Prevalence and causes of blindness at a tertiary hospital in Douala, Cameroon

PubMed Central

Eballé, André Omgbwa; Mvogo, Côme Ebana; Koki, Godefroy; Mounè, Nyouma; Teutu, Cyrille; Ellong, Augustin; Bella, Assumpta Lucienne

2011-01-01

Purpose The aim of this study was to determine the prevalence and causes of bilateral and unilateral blindness in the town of Douala and its environs based on data from the ophthalmic unit of a tertiary hospital in Douala. Methods We conducted a retrospective epidemiological survey of consultations at the eye unit of the Douala General Hospital over the last 20 years (from January 1, 1990 to December 31, 2009). Results Out of the 1927 cases of blindness, 1000 were unilateral, corresponding to a hospital prevalence of 1.84% and 927 cases were bilateral, corresponding to a hospital prevalence of 1.71%. No statistically significant difference was noted between the two (P = 0.14). The leading causes of bilateral blindness were cataract (50.1%), glaucoma (19.7%), and diabetic retinopathy (7.8%) while the leading causes of unilateral blindness were cataract (40.4%), glaucoma (14.1%), and retinal detachment (9.1%). Cataract (51.2%), cortical blindness (16.3%), and congenital glaucoma (10%) were the leading causes of bilateral blindness in children aged less than 10 years. Conclusion Blindness remains a public health problem in the Douala region with a hospital prevalence which is relatively higher than the national estimate given by the National Blindness Control Program. PMID:21966211

Contrast-balanced binocular treatment in children with deprivation amblyopia.

PubMed

Hamm, Lisa M; Chen, Zidong; Li, Jinrong; Dai, Shuan; Black, Joanna; Yuan, Junpeng; Yu, Minbin; Thompson, Benjamin

2017-11-28

Children with deprivation amblyopia due to childhood cataract have been excluded from much of the emerging research into amblyopia treatment. An investigation was conducted to determine whether contrast-balanced binocular treatment - a strategy currently being explored for children with anisometropic and strabismic amblyopia - may be effective in children with deprivation amblyopia. An unmasked, case-series design intended to assess proof of principle was employed. Eighteen children with deprivation amblyopia due to childhood cataracts (early bilateral n = 7, early unilateral n = 7, developmental n = 4), as well as 10 children with anisometropic (n = 8) or mixed anisometropic and strabismic amblyopia (n = 2) were prescribed one hour a day of treatment over a six-week period. Supervised treatment was available. Visual acuity, contrast sensitivity, global motion perception and interocular suppression were measured pre- and post-treatment. Visual acuity improvements occurred in the anisometropic/strabismic group (0.15 ± 0.05 logMAR, p = 0.014), but contrast sensitivity did not change. As a group, children with deprivation amblyopia had a smaller but statistically significant improvement in weaker eye visual acuity (0.09 ± 0.03 logMAR, p = 0.004), as well a significant improvement in weaker eye contrast sensitivity (p = 0.004). Subgroup analysis suggested that the children with early bilateral deprivation had the largest improvements, while children with early unilateral cataract did not improve. Interestingly, binocular contrast sensitivity also improved in children with early bilateral deprivation. Global motion perception improved for both subgroups with early visual deprivation, as well as children with anisometropic or mixed anisometropic/strabismic amblyopia. Interocular suppression improved for all subgroups except children with early unilateral deprivation. These data suggest that supervised contrast-balanced binocular treatment should be further investigated as a treatment option for children with deprivation amblyopia. However, for children with more severe deprivation amblyopia due to early unilateral cataracts, supplementary or alternative options should also be explored. © 2017 Optometry Australia.

Glaucoma-related adverse events in the first five years after unilateral cataract removal in the Infant Aphakia Treatment Study

PubMed Central

Freedman, Sharon F.; Lynn, Michael J.; Beck, Allen D.; Bothun, Erick D.; Orge, Faruk H.; Lambert, Scott R.

2015-01-01

Importance Glaucoma-related adverse events constitute major sight-threatening complications of cataract removal in infancy, yet their relationship to aphakia versus primary intraocular lens (IOL) implantation remains unsettled. Objective To identify and characterize cases of glaucoma and glaucoma-related adverse events (glaucoma+glaucoma suspect) among children in the Infant Aphakia Treatment Study (IATS) by the age of five years. Design, Setting, and Participants A multicenter randomized controlled trial of 114 infants with unilateral congenital cataract who were between age 1–6 months at surgery. Interventions Participants were randomized at cataract surgery to either primary IOL, or no IOL implantation (contact lens [CL]). Standardized definitions of glaucoma and glaucoma suspect were created for IATS and applied for surveillance and diagnosis. Main Outcome Measures Development of glaucoma and glaucoma+glaucoma suspect in operated eyes up to age five years, plus intraocular pressure, visual acuity, and axial length at age five years. Results Product limit estimates of the risk of glaucoma and glaucoma+glaucoma suspect at 4.8 years after surgery were 17% (95%CI=11%–25%) and 31% (95%CI=24%–41%), respectively. The CL and IOL groups were not significantly different for either outcome: glaucoma (hazard ratio(HR)=0.8[95%CI=0.3–2.0],p=0.62); glaucoma+glaucoma suspect: (HR=1.3[95%CI=0.6–2.5],p=0.58). Younger (versus older) age at surgery conferred increased risk of glaucoma (26% versus 9%, respectively at 4.8 years after surgery (HR=3.2[95%CI=1.2–8.3]), and smaller (versus larger) corneal diameter showed increased risk for glaucoma+glaucoma suspect (HR=2.5[95%CI=1.3–5.0]). Age and corneal diameter were significantly positively correlated. Glaucoma was predominantly open angle (19/20 cases, 95%), most eyes received medication (19/20, 95%), and 8/20 (40%) eyes had surgery. Conclusions and Relevance These results suggest that glaucoma-related adverse events are common and increase between one and five years in infants after unilateral cataract removal at 1–6 months of age; primary IOL placement does not mitigate their risk, but surgery at a younger age increases the risk. Longer follow-up of these children may further characterize risk factors, long-term outcomes, potential differences between eyes having primary IOL vs. aphakia, and optimal timing of unilateral congenital cataract removal. PMID:25996491

Incidence of environmental and genetic factors causing congenital cataract in Children of Lahore.

PubMed

Naz, Shagufta; Sharif, Saima; Badar, Hafsa; Rashid, Farzana; Kaleem, Afshan; Iqtedar, Mehwish

2016-07-01

To check the incidence of environmental and genetic factors causing congenital cataract in infants. The descriptive study was conducted at Layton Rahmatullah Benevolent Trust, Lahore, Pakistan, from October 2013 to April 2014, and comprised children under 15 years of age who had rubella syndrome, herpes simplex, birth trauma, trisomy 21, Nance-Horan syndrome or Lowe's syndrome. Of the 38,000 cases examined, 120(0.3%) patients were diagnosed with congenital cataract. Of them, 52(43.33%)were aged between 2 and 5 years,22(18.33%) <11 years and 10(8.33%) ?15 years. Bilateral congenital cataract was observed in 91(75.83%) patients and unilateral congenital cataract in 29(24.17%). Environmental factors caused 72(62.07%) cases and genetic factors caused 44(37.93%).. Congenital cataract predominated in boys compared to girls. Early diagnosis and adequate therapy requires specific technology, as well as long-term and permanent care..

Cataract surgery cost utility revisited in 2012: a new economic paradigm.

PubMed

Brown, Gary C; Brown, Melissa M; Menezes, Alicia; Busbee, Brandon G; Lieske, Heidi B; Lieske, Philip A

2013-12-01

To assess the 2012 cost utility of cataract surgery in the United States and to compare 2012 cost-utility data with those from 2000. Value-Based Medicine (Flourtown, PA), patient preference-based, comparative effectiveness analysis and cost-utility analysis using 2012 real United States dollars. Previously published Patient Outcomes Research Team Study data and time tradeoff utilities obtained from patients with vision loss. Visual acuity measurements from patients wtih untreated cataract were used as controls. Thirteen-year, average, first-eye and second-eye cataract surgery cost-utility analysis using the societal and third-party insurer cost perspectives. Patient value gain in quality-adjusted life years (QALYs) and percent gain in quality of life as well as the cost-utility ratio using the dollars expended per QALY gained. Patient and financial value outcomes were discounted at 3% annually with net present value analysis. First-eye cataract surgery conferred 1.6212 QALYs over the 13-year model, a 20.8% quality-of-life gain. Bilateral cataract surgery conferred 2.8152 QALYs over 13 years, a 36.2% improvement in quality of life. The direct ophthalmic medical cost for unilateral cataract surgery in 2012 United States nominal dollars was $2653, an inflation-adjusted 34.2% less than in 2000 and 85% less than in 1985. The 2012 inflation-adjusted physician fee was 10.1% of that in 1985. The 13-year societal cost perspective, financial return on investment (ROI) for first-eye cataract surgery was $121,198, a 4567% gain. The third-party insurer cost perspective average cost-utility ratio was $2653/1.6212 = $1636/QALY for unilateral cataract surgery, whereas the societal cost perspective average cost-utility ratio was -$121,198/1.6212 = -$74,759/QALY. The net 13-year $123.4-billion financial ROI from a 1-year cohort of cataract surgery patients was accrued: Medicare, $36.4 billion; Medicaid, $3.3 billion; other insurers, $9.6 billion; patients, $48.6 billion; and increased United States national productivity, $25.4 billion. Cataract surgery in 2012 greatly improved quality of life and was highly cost effective. It was 34.4% less expensive than in 2000 and 85% less expensive than in 1985. Initial cataract surgery yielded an extraordinary 4567% financial ROI to society over the 13-year model. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Rabbits with naturally occurring cataracts referred for phacoemulsification and intraocular lens implantation: a preliminary study of 12 cases.

PubMed

Sanchez, Rick F; Everson, Richard; Hedley, Joanna; Dawson, Charlotte; Lam, Richard; Priestnall, Simon L; Garcia de Carellan, Alejandra; de Miguel, Cristina; Seymour, Christopher

2017-12-04

To describe the presentation of 15 rabbits with naturally occurring cataracts referred for phacoemulsification surgery, the procedure in 13 cases and the follow-up in 12. Fifteen rabbits (30 eyes), nine of which stopped following visual cues in association with cataract progression. Rabbits underwent preoperative ophthalmic and ocular ultrasound examination. Thirteen rabbits (22 eyes) had mature cataracts. Ten were bilateral and three unilateral. Two rabbits had an anterior chamber abscess. The cataract in one of these was incipient. One rabbit had bilateral immature cataracts. One rabbit had a subluxated lens, and one had a retinal detachment. Thirteen rabbits (22 eyes) underwent phacoemulsification. Eighteen, 13.5-mm capsular tension rings (CTRs) and seventeen, 13-mm IOLs (Acrivet ® , Berlin, Germany) were fitted including one 41D 60V-model, and three 49D and thirteen 58D 20S-models. Intraoperative complications included one unilateral posterior-capsular tear, one lens subluxation, and one expulsive choroidal hemorrhage. One rabbit died during anesthetic recovery. Nine cases were PCR-tested for Encephalitozoon cuniculi, and only three were positive. The median follow-up time was 12 months (4-24 months). Rabbits that were not following visual cues preoperatively did so postoperatively, and surgery resulted in a clear visual axis for the follow-up period in every case except in two, due to reasons other than the surgery. Phacoemulsification with CTR and IOL implantation offers good long-term results and can improve the quality of life of pet rabbits. Retinal detachment, lens luxation, expulsive choroidal hemorrhage, and anesthetic death are potential complications. © 2017 American College of Veterinary Ophthalmologists.

Risk of cataract in persons with cytomegalovirus retinitis and the acquired immune deficiency syndrome.

PubMed

Kempen, John H; Sugar, Elizabeth A; Lyon, Alice T; Lewis, Richard Alan; Jabs, Douglas A; Heinemann, Murk-Hein; Dunn, James P

2012-11-01

To evaluate cataract risk in eyes of patients with AIDS and cytomegalovirus (CMV) retinitis and to identify risk factors. Prospective cohort study. Patients with AIDS and CMV retinitis. Patients 13 years of age and older were enrolled between 1998 and 2008. Demographic and clinical characteristics, slit-lamp biomicroscopy findings, and dilated ophthalmoscopy results were documented at quarterly visits. Cataract status was determined at the initial visit (prevalence) and at follow-up visits (incidence). For cataract, a high grade of lens opacity by biomicroscopy to which best-corrected visual acuity worse than 20/40 was attributed. Eyes that had undergone cataract surgery before enrollment or between visits also were counted as having cataract. Seven hundred twenty-nine eyes of 489 patients diagnosed with CMV retinitis were evaluated. Higher prevalence was observed for patients with bilateral versus unilateral CMV retinitis (adjusted odds ratio [aOR], 2.74; 95% confidence interval [CI], 1.76-4.26) and, among unilateral CMV retinitis cases, for eyes with retinitis versus without retinitis (15% vs. 1.4%; P<0.0001). The age-adjusted prevalence of cataract among CMV retinitis cases was higher than that in a population-based sample (P<0.0001). Cataract prevalence increased with age (aOR, 11.77; 95% CI, 2.28-60.65 for age ≥ 60 years vs. younger than 40 years) and longer duration of retinitis (aOR, 1.36; 95% CI, 1.20-1.54 per year). Among eyes with CMV retinitis initially free of cataract, the cataract incidence was 8.1%/eye-year (95% CI, 6.7%-10.0%). Prior retinal detachment was associated with higher cataract risk (if repaired with silicone oil: adjusted hazard ratio [aHR], 10.37; 95% CI, 6.51-16.52; otherwise: aHR, 2.90; 95% CI, 1.73-4.87). Large CMV retinitis lesions also were associated with higher risk of cataract (for involvement of 25-49% retinal area: aHR, 2.30; 95% CI, 1.51-3.50; for ≥ 50% involvement: aHR, 3.63; 95% CI, 2.18-6.04), each with respect to ≤ 24% involvement, as were anterior segment inflammation (aHR, 2.27; 95% CI, 1.59-3.25) and contralateral cataract (aHR, 2.52; 95% CI, 1.74-3.66). Cytomegalovirus retinitis is associated with a high absolute and relative risk of cataract. Among several risk factors, large retinal lesion size and use of silicone oil in retinal detachment repair are potentially modifiable, albeit not in all cases. Cataract is likely to be an increasingly important cause of visual morbidity in this population. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Risk of Cataract in Persons with Cytomegalovirus Retinitis and the Acquired Immune Deficiency Syndrome

PubMed Central

Kempen, John H.; Sugar, Elizabeth A.; Lyon, Alice T.; Lewis, Richard Alan; Jabs, Douglas A.; Heinemann, Murk-Hein; Dunn, James P.

2012-01-01

Objective To evaluate cataract risk in eyes of patients with AIDS and cytomegalovirus (CMV) retinitis and to identify risk factors. Design Prospective cohort study. Participants Patients with AIDS and CMV retinitis. Methods Patients 13 years of age and older were enrolled between 1998 and 2008. Demographic and clinical characteristics, slit-lamp biomicroscopy findings, and dilated ophthalmoscopy results were documented at quarterly visits. Cataract status was determined at the initial visit (prevalence) and at follow-up visits (incidence). Main Outcome Measures For cataract, a high grade of lens opacity by biomicroscopy to which best-corrected visual acuity worse than 20/40 was attributed. Eyes that had undergone cataract surgery before enrollment or between visits also were counted as having cataract. Results Seven hundred twenty-nine eyes of 489 patients diagnosed with CMV retinitis were evaluated. Higher prevalence was observed for patients with bilateral versus unilateral CMV retinitis (adjusted odds ratio [aOR], 2.74; 95% confidence interval [CI], 1.76–4.26) and, among unilateral CMV retinitis cases, for eyes with retinitis versus without retinitis (15% vs. 1.4%; P<0.0001). The age-adjusted prevalence of cataract among CMV retinitis cases was higher than that in a population-based sample (P<0.0001). Cataract prevalence increased with age (aOR, 11.77; 95% CI, 2.28–60.65 for age ≥60 years vs. younger than 40 years) and longer duration of retinitis (aOR, 1.36; 95% CI, 1.20–1.54 per year). Among eyes with CMV retinitis initially free of cataract, the cataract incidence was 8.1%/eye-year (95% CI, 6.7%–10.0%). Prior retinal detachment was associated with higher cataract risk (if repaired with silicone oil: adjusted hazard ratio [aHR], 10.37; 95% CI, 6.51–16.52; otherwise: aHR, 2.90; 95% CI, 1.73–4.87). Large CMV retinitis lesions also were associated with higher risk of cataract (for involvement of 25–49% retinal area: aHR, 2.30; 95% CI, 1.51–3.50; for ≥50% involvement: aHR, 3.63; 95% CI, 2.18–6.04), each with respect to ≤24% involvement, as were anterior segment inflammation (aHR, 2.27; 95% CI, 1.59–3.25) and contralateral cataract (aHR, 2.52; 95% CI, 1.74–3.66). Conclusions Cytomegalovirus retinitis is associated with a high absolute and relative risk of cataract. Among several risk factors, large retinal lesion size and use of silicone oil in retinal detachment repair are potentially modifiable, albeit not in all cases. Cataract is likely to be an increasingly important cause of visual morbidity in this population. PMID:22853972

Comparison of contact lens and intraocular lens correction of monocular aphakia during infancy: a randomized clinical trial of HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.

PubMed

Lambert, Scott R; Lynn, Michael J; Hartmann, E Eugenie; DuBois, Lindreth; Drews-Botsch, Carolyn; Freedman, Sharon F; Plager, David A; Buckley, Edward G; Wilson, M Edward

2014-06-01

The efficacy and safety of primary intraocular lens (IOL) implantation during early infancy is unknown. To compare the visual outcomes of patients optically corrected with contact lenses vs IOLs following unilateral cataract surgery during early infancy. The Infant Aphakia Treatment Study is a randomized clinical trial with 5 years of follow-up that involved 114 infants with unilateral congenital cataracts at 12 sites. A traveling examiner assessed visual acuity at age 4.5 years. Cataract surgery with or without primary IOL implantation. Contact lenses were used to correct aphakia in patients who did not receive IOLs. Treatment was determined through random assignment. HOTV optotype visual acuity at 4.5 years of age. The median logMAR visual acuity was not significantly different between the treated eyes in the 2 treatment groups (both, 0.90 [20/159]; P = .54). About 50% of treated eyes in both groups had visual acuity less than or equal to 20/200. Significantly more patients in the IOL group had at least 1 adverse event after cataract surgery (contact lens, 56%; IOL, 81%; P = .02). The most common adverse events in the IOL group were lens reproliferation into the visual axis, pupillary membranes, and corectopia. Glaucoma/glaucoma suspect occurred in 35% of treated eyes in the contact lens group vs 28% of eyes in the IOL group (P = .55). Since the initial cataract surgery, significantly more patients in the IOL group have had at least 1 additional intraocular surgery (contact lens, 21%; IOL, 72%; P < .001). There was no significant difference between the median visual acuity of operated eyes in children who underwent primary IOL implantation and those left aphakic. However, there were significantly more adverse events and additional intraoperative procedures in the IOL group. When operating on an infant younger than 7 months of age with a unilateral cataract, we recommend leaving the eye aphakic and focusing the eye with a contact lens. Primary IOL implantation should be reserved for those infants where, in the opinion of the surgeon, the cost and handling of a contact lens would be so burdensome as to result in significant periods of uncorrected aphakia. clinicaltrials.gov Identifier: NCT00212134

Survey of childhood blindness and visual impairment in Botswana.

PubMed

Nallasamy, Sudha; Anninger, William V; Quinn, Graham E; Kroener, Brian; Zetola, Nicola M; Nkomazana, Oathokwa

2011-10-01

In terms of blind-person years, the worldwide burden of childhood blindness is second only to cataracts. In many developing countries, 30-72% of childhood blindness is avoidable. The authors conducted this study to determine the causes of childhood blindness and visual impairment (VI) in Botswana, a middle-income country with limited access to ophthalmic care. This study was conducted over 4 weeks in eight cities and villages in Botswana. Children were recruited through a radio advertisement and local outreach programmes. Those ≤ 15 years of age with visual acuity <6/18 in either eye were enrolled. The WHO/Prevention of Blindness Eye Examination Record for Children with Blindness and Low Vision was used to record data. The authors enrolled 241 children, 79 with unilateral and 162 with bilateral VI. Of unilateral cases, 89% were avoidable: 23% preventable (83% trauma-related) and 66% treatable (40% refractive error and 31% amblyopia). Of bilateral cases, 63% were avoidable: 5% preventable and 58% treatable (33% refractive error and 31% congenital cataracts). Refractive error, which is easily correctable with glasses, is the most common cause of bilateral VI, with cataracts a close second. A nationwide intervention is currently being planned to reduce the burden of avoidable childhood VI in Botswana.

Causes of low vision and blindness in rural Indonesia

PubMed Central

Saw, S-M; Husain, R; Gazzard, G M; Koh, D; Widjaja, D; Tan, D T H

2003-01-01

Aim: To determine the prevalence rates and major contributing causes of low vision and blindness in adults in a rural setting in Indonesia Methods: A population based prevalence survey of adults 21 years or older (n=989) was conducted in five rural villages and one provincial town in Sumatra, Indonesia. One stage household cluster sampling procedure was employed where 100 households were randomly selected from each village or town. Bilateral low vision was defined as habitual VA (measured using tumbling “E” logMAR charts) in the better eye worse than 6/18 and 3/60 or better, based on the WHO criteria. Bilateral blindness was defined as habitual VA worse than 3/60 in the better eye. The anterior segment and lens of subjects with low vision or blindness (both unilateral and bilateral) (n=66) were examined using a portable slit lamp and fundus examination was performed using indirect ophthalmoscopy. Results: The overall age adjusted (adjusted to the 1990 Indonesia census population) prevalence rate of bilateral low vision was 5.8% (95% confidence interval (CI) 4.2 to 7.4) and bilateral blindness was 2.2% (95% CI 1.1 to 3.2). The rates of low vision and blindness increased with age. The major contributing causes for bilateral low vision were cataract (61.3%), uncorrected refractive error (12.9%), and amblyopia (12.9%), and the major cause of bilateral blindness was cataract (62.5%). The major causes of unilateral low vision were cataract (48.0%) and uncorrected refractive error (12.0%), and major causes of unilateral blindness were amblyopia (50.0%) and trauma (50.0%). Conclusions: The rates of habitual low vision and blindness in provincial Sumatra, Indonesia, are similar to other developing rural countries in Asia. Blindness is largely preventable, as the major contributing causes (cataract and uncorrected refractive error) are amenable to treatment. PMID:12928268

Incidence and risk factors for chronic uveitis following cataract surgery.

PubMed

Patel, Chirag; Kim, Stephen Jae; Chomsky, Amy; Saboori, Mazeyar

2013-04-01

To determine the incidence of and associated risk factors for uveitis after cataract surgery. A total of 17,757 eyes were identified and records of 42 eyes that developed uveitis and 2320 eyes that did not were reviewed. Postsurgical uveitis was defined as persistent inflammation for ≥ 6 months after surgery. Forty-two eyes of 35 patients developed uveitis (0.24%). Eleven patients underwent consecutive cataract surgery but developed unilateral uveitis, and intraoperative complications occurred in 55% of uveitic eyes compared to 0% in fellow eyes (p < 0.05). Median duration of inflammation was 8 and 11.5 months in eyes with and without vitrectomy (p < 0.05). Intraocular complications occurred in 44 and 8.3% of eyes that did and did not develop uveitis, respectively (p = 0.01). Postsurgical uveitis developed after approximately 1 in 400 cataract surgeries and occurred more frequently in eyes experiencing intraoperative complications.

21 CFR 886.1460 - Stereopsis measuring instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stereopsis measuring instrument. 886.1460 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1460 Stereopsis measuring instrument. (a) Identification. A stereopsis measuring instrument is a device intended to measure depth...

Survey of childhood blindness and visual impairment in Botswana

PubMed Central

Nallasamy, Sudha; Anninger, William V; Quinn, Graham E; Kroener, Brian; Zetola, Nicola M; Nkomazana, Oathokwa

2014-01-01

Background/aims In terms of blind-person years, the worldwide burden of childhood blindness is second only to cataracts. In many developing countries, 30–72% of childhood blindness is avoidable. The authors conducted this study to determine the causes of childhood blindness and visual impairment (VI) in Botswana, a middle-income country with limited access to ophthalmic care. Methods This study was conducted over 4 weeks in eight cities and villages in Botswana. Children were recruited through a radio advertisement and local outreach programmes. Those ≤15 years of age with visual acuity <6/18 in either eye were enrolled. The WHO/Prevention of Blindness Eye Examination Record for Children with Blindness and Low Vision was used to record data. Results The authors enrolled 241 children, 79 with unilateral and 162 with bilateral VI. Of unilateral cases, 89% were avoidable: 23% preventable (83% trauma-related) and 66% treatable (40% refractive error and 31% amblyopia). Of bilateral cases, 63% were avoidable: 5% preventable and 58% treatable (33% refractive error and 31% congenital cataracts). Conclusion Refractive error, which is easily correctable with glasses, is the most common cause of bilateral VI, with cataracts a close second. A nationwide intervention is currently being planned to reduce the burden of avoidable childhood VI in Botswana. PMID:21242581

Sensitive period in stereopsis: random dot stereopsis after long-standing strabismus.

PubMed

Hatch, S W; Laudon, R

1993-12-01

Bifoveal fixation is a requirement for random dot stereopsis. It is believed that random dot stereopsis is not possible after treatment of long-standing strabismus because binocular cortical cells are permanently damaged when strabismus is present during the sensitive period. Although the sensitive period for amblyopia has been clearly documented, the sensitive period for stereopsis is uncertain. We present a case we have followed from age 22 months to 10 years. This patient had intermittent esotropia until approximately age 3 years 4 months; he then had constant esotropia from about age 3 years 4 months to age 9 years 7 months. After orthoptic treatment at age 9 years, the patient returned to intermittent esotropia. He subsequently developed bifoveal fixation as measured by 30 sec arc of contour stereopsis and 250 to 500 sec arc of random dot stereopsis. This patient demonstrates that bifoveal fixation can be obtained after long-standing strabismus. We suggest that the sensitive period for stereopsis development, for this patient, was from birth to age 3 years.

Cataract formation associated with ocular toxocariasis.

PubMed

Ahn, Seong Joon; Woo, Se Joon; Hyon, Joon Young; Park, Kyu Hyung

2013-06-01

To report the clinical features of cataracts in eyes with ocular toxocariasis. Department of Ophthalmology, Seoul National University Bundang Hosptal, Seongnam, South Korea. Retrospective observational case series. The clinical diagnosis of ocular toxocariasis was based on the following characteristic features: retinal granuloma with or without ocular inflammation and positive results in serum antibody enzyme-linked immunosorbent assay. Patients younger than 60 years who presented with a unilateral cataract and were diagnosed with ocular toxocariasis between January 2009 and January 2012 were included. Demographic and ocular examination data for all patients showing atypical cataract features were collected. All cataracts were documented with anterior segment photography. Seven of 83 patients (8.4%) presented with an atypical cataract in the eye with ocular toxocariasis only. The mean patient age was 49.7 years ± 8.3 (SD) (range 38 to 59 years). All patients had small, round, white lens opacities resembling retinal granulomas. The granuloma-like opacities were located primarily in the lens midperiphery and in the subcapsular level. The lens opacity migrated in 1 patient. Ocular toxocariasis can cause a cataract with distinctive clinical features. These cataracts show a granuloma-like opacity primarily in the posterior subcapsular level; the opacity can migrate. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

The role of stereopsis (three-dimensional vision) in dentistry: review of the current literature.

PubMed

Syrimi, M; Ali, N

2015-05-22

Clinical dental work is placing increasing demands on a clinician's vision as new techniques that require fine detail become more common. High hand-eye coordination requires good visual acuity as well as other psychological and neurological qualities such as stereopsis. Stereopsis (three-dimensional vision) is the highest form of depth perception obtained by visual disparity of images formed in the retinas of two eyes. It is believed to confer functional benefits on everyday tasks such as hand-eye coordination. Although its role in depth perception has long been established, little is known regarding the importance of stereopsis in dentistry. This article reviews the role of stereopsis in everyday life and the available literature on the importance of stereopsis in dentistry.

Staphyloma in a cat.

PubMed

Skorobohach, Brian J; Hendrix, Diane V H

2003-06-01

A unilateral scleral staphyloma in an 18-month-old, female spayed Domestic Short-haired cat was treated with excision, primary closure and fascial graft. Other ocular abnormalities noted on examination included iris coloboma, anterior cortical cataract, focal lens equator flattening and retinal dysplasia. The staphyloma was presumed to be congenital in origin.

Outcomes and projected impact on vision restoration of the China Million Cataract Surgeries Program.

PubMed

Yan, Xixi; Guan, Chunhong; Mueller, Andreas; Iezzi, Beatrice; He, Mingguang; Liang, Hui; Meltzer, Mirjam; Congdon, Nathan G

2013-10-01

The recently completed Chinese "Million Cataract Surgeries Program" (MCSP) is among the largest such campaigns ever, providing 1.05 million operations. We report MCSP outcomes for the first time, in Jiangxi, the province with the greatest program output. Ten county hospitals participating in MCSP were selected in Jiangxi (range of gross domestic product per capita US$743-2998). Each hospital sought to enroll 75 consecutive MCSP patients aged ≥ 50 years. Data recorded included type of cataract procedure, bilateral uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), and refractive error pre- and ≥ 50 days postoperatively. Among 715 patients (mean age 72.3 ± 9.1 years, 55.5% female), preoperative UCVA was <3/60 (legally blind) bilaterally in 13.3% and unilaterally in the operated eye in 50.9%. No subjects had UCVA >6/18 preoperatively. Small incision cataract surgery was performed in 92.3% patients. Among 662 patients (92.6%) completing follow-up was ≥ 40 days after surgery, BCVA was ≥ 6/18 in 80.1%, UCVA was ≥ 6/18 in 57.1% and UCVA was <3/60 in 2.1%. Older age (p < 0.001), female sex (p = 0.04), worse refractive error (p = 0.02) and presence of intra- (p = 0.002) and postoperative surgical complications (p < 0.001), were independently associated with worse postoperative UCVA. Based on these results, the MCSP cured an estimated 124,950 cases (13.3% × [100-2.1%] × 1.05 million) of bilateral and 502,500 (50.9% × [100-2.1%] × 1.05 million) of unilateral blindness. Due to relatively good outcomes and the large number of surgeries performed on blind persons, the sight-restoring impact of the MCSP was probably substantial.

The pursuit of stereopsis.

PubMed

Sharma, Pradeep

2018-02-01

Pediatric ophthalmologists are increasingly expected to promote, preserve, and restore binocular vision. Clinical studies on restoring alignment and stereopsis in the management of amblyopia, esotropia, exotropia, and complex strabismus are reviewed from the perspective of the author's published work and personal experiences. Treatment of amblyopia by means of optical rehabilitation, occlusion, or penalization has been reinforced by medical treatment and perceptual training with monocular or binocular video games. Studies indicate that early management of esotropia and alignment within 8 Δ is required for regaining stereopsis. In the surgical management of intermittent exotropia, distance stereopsis by Frisby Davis Distance stereotest can predict better stereopsis, with patients having preoperative distance stereopsis of <70 arcsec less likely to improve after surgery. The surgeon's armamentarium for correcting alignment and restoring binocular vision include procedures such as adjustable, partial vertical rectus muscle transposition in cases of exotropic Duane syndrome and lateral rectus palsy, periosteal fixation of the globe or of the lateral rectus muscle, and medial transposition of the split lateral rectus muscle. The goal for present-day strabismologists is not merely to correct strabismus but also to achieve alignment of eyes in time to ensure normal development of stereopsis in children and to restore alignment and stereopsis in adults. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

The effects of absence of stereopsis on performance of a simulated surgical task in two-dimensional and three-dimensional viewing conditions

PubMed Central

Bloch, Edward; Uddin, Nabil; Gannon, Laura; Rantell, Khadija; Jain, Saurabh

2015-01-01

Background Stereopsis is believed to be advantageous for surgical tasks that require precise hand-eye coordination. We investigated the effects of short-term and long-term absence of stereopsis on motor task performance in three-dimensional (3D) and two-dimensional (2D) viewing conditions. Methods 30 participants with normal stereopsis and 15 participants with absent stereopsis performed a simulated surgical task both in free space under direct vision (3D) and via a monitor (2D), with both eyes open and one eye covered in each condition. Results The stereo-normal group scored higher, on average, than the stereo-absent group with both eyes open under direct vision (p<0.001). Both groups performed comparably in monocular and binocular monitor viewing conditions (p=0.579). Conclusions High-grade stereopsis confers an advantage when performing a fine motor task under direct vision. However, stereopsis does not appear advantageous to task performance under 2D viewing conditions, such as in video-assisted surgery. PMID:25185439

Visual functions in amblyopia as determinants of response to treatment.

PubMed

Singh, Vinita; Agrawal, Siddharth

2013-01-01

To describe the visual functions in amblyopia as determinants of response to treatment. Sixty-nine patients with unilateral and bilateral amblyopia (114 amblyopic eyes) 3 to 15 years old (mean age: 8.80 ± 2.9 years), 40 males (58%) and 29 females (42%), were included in this study. All patients were treated by conventional occlusion 6 hours per day for mild to moderate amblyopia (visual acuity 0.70 or better) and full-time for 4 weeks followed by 6 hours per day for severe amblyopia (visual acuity 0.8 or worse). During occlusion, near activities requiring hand-eye coordination were advised. The follow-up examination was done at 3 and 6 months. Improvement in visual acuity was evaluated on the logMAR chart and correlated with the visual functions. Statistical analysis was done using Wilcoxon rank sum test (Mann-Whitney U test) and Kruskal-Wallis analysis. There was a statistically significant association of poor contrast sensitivity with the grade of amblyopia (P < .001). The grade of amblyopia (P < .01), accommodation (P < .01), stereopsis (P = .01), and mesopic visual acuity (P < .03) were found to have a correlation with response to amblyopia therapy. The grade of amblyopia (initial visual acuity) and accommodation are strong determinants of response to amblyopia therapy, whereas stereopsis and mesopic visual acuity have some value as determinants. Copyright 2013, SLACK Incorporated.

Accidental injections of dexamethasone intravitreal implant (Ozurdex) into the crystalline lens.

PubMed

Coca-Robinot, Javier; Casco-Silva, Bruno; Armadá-Maresca, Felix; García-Martínez, Jesús

2014-01-01

To describe the side effects and management after inadvertent injection of a dexamethasone implant (Ozurdex) into the crystalline lens. Two case reports. Two patients with macular edema due to unilateral retinal vein occlusion were scheduled for an intravitreal injection of Ozurdex. During the procedure, the implant was accidentally injected into the crystalline lens. Both patients developed cataracts during the course of several weeks and in both there was an intraocular pressure (IOP) increase, which required treatment with topical hypotensives. Macular edema improved only slightly. Cataract surgery with uneventful removal of the implant was performed 3 (case 1) and 6 months (case 2) after the injection. After inadvertent injection of Ozurdex into the crystalline lens, cataract surgery with removal of the implant should be performed as soon as possible in order to avoid IOP increase and so that the underlying condition may be treated adequately.

Vision impairment and major causes of vision loss impacts on vision-specific functioning independent of socioeconomic factors.

PubMed

Chiang, Peggy P C; Zheng, Yingfeng; Wong, Tien Y; Lamoureux, Ecosse L

2013-02-01

To quantify the eye disease-specific impact of unilateral and bilateral vision impairment (VI) on vision-specific functioning (VF). The Singapore Indian Eye population-based study. Ethnic Indians older than 40 years of age living in Singapore. Participants underwent standardized ophthalmic assessments for VI and blindness, defined using presenting visual acuity (United States definition). Sociodemographic data were recorded using a standardized questionnaire. Rasch analysis was used to validate the Visual Function Index 11 and to determine its psychometric properties. The major causes of VI (i.e., cataract, refractive error, age-related macular degeneration, diabetic retinopathy [DR], and glaucoma) were determined by ophthalmologists on examination. Multivariate linear regression analysis was performed to assess the impact of VI on the overall VF Rasch score. Vision-specific functioning. Three thousand three hundred ninety-six persons were analyzed. Participants with VI had a systematic reduction in VF score compared with those with normal vision in both eyes, ranging from -11.2% normal vision in one eye and low vision in the other eye (95% confidence interval [CI], -12.2% to -10.3%; P<0.001), to -12.7% blindness in one eye and normal vision in the other eye (CI, -15.1% to -10.4%; P<0.001), to -19.4% low vision in both eyes (CI, -20.8% to -18.1%; P<0.001), to -52.9% blindness in one eye and low vision in other eye (CI, -55.3% to -50.4%; P<0.001), to -77.2% blindness in both eyes (CI, -82.4% to 72.0%; P<0.001). The impact of VI on VF score varied across different major causes of vision loss, regardless of socioeconomic factors. Vision impairment attributed to cataract in one or both eyes had a significant decrease in VF score by 17.7% and 22.3%, respectively, compared with those with normal vision in both eyes (P<0.001). The impact of unilateral and bilateral VI on VF score was greater in participants with glaucoma (32.2% in unilateral cases and 35.9% in bilateral cases; P<0.001) and DR (29.4% in unilateral cases and 33.3% in bilateral cases; P<0.001). Vision impairment and major age-related eye diseases such as cataract, DR, and glaucoma are associated significantly with worse deterioration in VF, regardless of education level, literacy adequacy, or immigration pattern. Glaucoma and DR seemed to have a greater negative impact on VF score compared with cataract. This study highlights the importance of disease-specific interventions in reducing the adverse impact of VI on daily activities. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Willingness to pay for cataract surgery in Kathmandu valley.

PubMed

Shrestha, M K; Thakur, J; Gurung, C K; Joshi, A B; Pokhrel, S; Ruit, S

2004-03-01

A cross sectional study was carried out on 78 screened cataract patients of two screening camps in Kathmandu valley, Nepal, to assess the willingness to pay for cataract surgery. A non-probability sampling technique with open ended and close ended questionnaires was used. The average age of patients was 68.8 years. The ratio of men and women was 0.9:1. 42.3% (33) of patients were willing to pay for cataract surgery. Among them 48.5% (16) of people were willing to pay less than dollars 13 and 51.5% (17) were willing to pay more than dollars 13. The mean was dollars 2.3 (SD dollars 15.5) per case. Patients with bilateral cataract were more willing to pay than unilateral cases. Poverty (44.4%, 20) was the main barrier for unwillingness to pay for cataract surgery. Other reasons were the lack of family support (28.9%, 13), lack of knowledge of surgery and belief that it was an unnecessary procedure (15.6%, seven), and waiting for a free surgical service (11.1%, five). This study clearly indicates that although there was awareness of the availability of treatment and services provided within the reach, people are not willing to pay for the surgery and use the facility primarily because of poverty. Hence, to change patients' attitudes, a more holistic approach is needed, keeping in view the cultural, social, and economic background of the society.

Long-Term Visual Outcomes of Secondary Intraocular Lens Implantation in Children with Congenital Cataracts

PubMed Central

Jiang, Yongxiang; Lu, Yi

2015-01-01

Aim The aim of this study was to evaluate the long-term visual outcomes and factors affecting visual results in children undergoing secondary intraocular lens (IOL) implantation following primary congenital cataract extraction. Methods Children with congenital cataracts who underwent secondary IOL implantation for aphakia at the Eye and ENT Hospital of Fudan University between January 1, 2001, and December 31, 2007, were retrospectively reviewed. One eye was randomly selected in children with bilateral cataracts. Laterality, type of cataract (total or partial opacity), sex, age at primary and secondary surgeries, visual axis opacity (VAO), compliance with amblyopia therapy, postoperative ocular complications, refractive error, ocular alignment, and best corrected visual acuity (BCVA) at last follow-up were recorded; potential factors that might have affected the visual results were evaluated. Results Seventy-six bilateral and 34 unilateral congenital cataract cases were analyzed; the mean ages of the children were 12.70±5.06 and 12.50±2.71 years at final follow-up, the mean follow-up periods from IOL implantation were 94.93±24.22 and 109.09±18.89 months, and the mean BCVA (Log MAR) values were 0.51±0.37 and 1.05±0.46, respectively. Final BCVA after secondary IOL implantation was significantly associated with laterality, type of cataract, age at primary cataract extraction, compliance with amblyopia therapy, and refractive correction after surgery. No significant associations were found between BCVA and sex, age at secondary IOL implantation, VAO, or other ocular complications. The most common ocular complications were VAO and elevated intraocular pressure after surgery. There were no other complications, with the exception of one eye with IOL dislocation. Conclusions The results indicate that the important determinants of long-term visual outcomes in children with congenital cataracts undergoing secondary IOL implantation are laterality, cataract type, age at initial cataract extraction, compliance with amblyopia therapy, and refractive error. PMID:26230501

Stereopsis and positional acuity under dark adaptation.

PubMed

Livingstone, M S; Hubel, D H

1994-03-01

Though experience tells us we can perceive depth in dim light, it is not so obvious that one of the chief mechanisms for depth perception, stereopsis, is possible under scotopic conditions. The only studies on human stereopsis in the dark adapted state seem to be those of Nagel [(1902) Zeitschrift für Psychologie, 27, 264-266] and Mueller and Lloyd [(1948) Proceedings of the National Academy of Science, U.S.A., 34, 223-227], both of which used real objects or line stereograms. We tested stereopsis using both random-dot and line stereograms and, in agreement with these studies, found that stereopsis is indeed possible in dark adaptation. We also measured stereo acuity and positional acuity (both of which are examples of hyperacuity) and compared these with grating acuity at several levels of light and dark adaptation. At all illumination levels tested, acuities for stereopsis and relative line position were both higher than for grating acuity. As light levels decreased, positional and grating acuity declined in parallel fashion, whereas stereoacuity declined more steeply.

Determination of depth-viewing volumes for stereo three-dimensional graphic displays

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Williams, Steven P.

1990-01-01

Real-world, 3-D, pictorial displays incorporating true depth cues via stereopsis techniques offer a potential means of displaying complex information in a natural way to prevent loss of situational awareness and provide increases in pilot/vehicle performance in advanced flight display concepts. Optimal use of stereopsis requires an understanding of the depth viewing volume available to the display designer. Suggested guidelines are presented for the depth viewing volume from an empirical determination of the effective region of stereopsis cueing (at several viewer-CRT screen distances) for a time multiplexed stereopsis display system. The results provide the display designer with information that will allow more effective placement of depth information to enable the full exploitation of stereopsis cueing. Increasing viewer-CRT screen distances provides increasing amounts of usable depth, but with decreasing fields-of-view. A stereopsis hardware system that permits an increased viewer-screen distance by incorporating larger screen sizes or collimation optics to maintain the field-of-view at required levels would provide a much larger stereo depth-viewing volume.

Cataract in a patient with 47,XYY sex chromosome aneuploidy.

PubMed

Medina-Andrade, A; Villanueva-Mendoza, C; Arenas, S; Cortés-González, V

2018-06-01

The case concerns a 16 year-old boy with a history of high myopia and unilateral congenital cataract, tall stature for age, facial dysmorphism, hypermobile metacarpal-phalangeal joints, as well as behavioural problems. The mother had a history of recurrent pregnancy loss. Chromosomal analysis of the peripheral blood lymphocytes reported 47,XYY. Patients with sex chromosome aneuploidy 47,XYY have higher risk of congenital malformations, although ophthalmological anomalies are unusual. Evaluation of patients with tall stature and behavioural problems should include a chromosomal analysis in order to determine the aetiology. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Unilateral retinitis pigmentosa: 30 years follow-up

PubMed Central

Weller, Julia M; Michelson, Georg; Juenemann, Anselm G

2014-01-01

This case report depicts the clinical course of a female patient with unilateral retinitis pigmentosa (RP), who presented first in 1984 at the age of 43 years. At the beginning, there were cells in the vitreous leading to the diagnosis of uveitis with vasculitis. Within 30 years, the complete clinical manifestation of RP developed with bone spicule-shaped pigment deposits, pale optic disc, narrowed arterioles, cystoid macular oedema, posterior subcapsular cataract, concentric narrowing of the visual field and undetectable electroretinogram signal. At the age of 72 years, there are still no signs of retinal dystrophy in the other eye. PMID:24515232

Monitoring and Morphologic Classification of Pediatric Cataract Using Slit-Lamp-Adapted Photography.

PubMed

Long, Erping; Lin, Zhuoling; Chen, Jingjing; Liu, Zhenzhen; Cao, Qianzhong; Lin, Haotian; Chen, Weirong; Liu, Yizhi

2017-11-01

To investigate the feasibility of pediatric cataract monitoring and morphologic classification using slit lamp-adapted anterior segmental photography in a large cohort that included uncooperative children. Patients registered in the Childhood Cataract Program of the Chinese Ministry of Health were prospectively selected. Eligible patients underwent slit-lamp adapted anterior segmental photography to record and monitor the morphology of their cataractous lenses. A set of assistance techniques for slit lamp-adapted photography was developed to instruct the parents of uncooperative children how to help maintain the child's head position and keep the eyes open after sleep aid administration. Briefly, slit lamp-adapted photography was completed for all 438 children, including 260 (59.4%) uncooperative children with our assistance techniques. All 746 images of 438 patients successfully confirmed the diagnoses and classifications. Considering the lesion location, pediatric cataract morphologies could be objectively classified into the seven following types: total; nuclear; polar, including two subtypes (anterior and posterior); lamellar; nuclear combined with cortical, including three subtypes (coral-like, dust-like, and blue-dot); cortical; and Y suture. The top three types of unilateral cataracts were polar (55, 42.3%), total (42, 32.3%), and nuclear (23, 17.7%); and the top three types of bilateral cataracts were nuclear (110, 35.8%), total (102, 33.2%), and lamellar (34, 11.1%). Slit lamp-adapted anterior segmental photography is applicable for monitoring and classifying the morphologies of pediatric cataracts and is even safe and feasible for uncooperative children with assistance techniques and sleep aid administration. This study proposes a novel strategy for the preoperative evaluation and evidence-based management of pediatric ophthalmology (Clinical Trials.gov, NCT02748031).

A laminar cortical model of stereopsis and 3D surface perception: closure and da Vinci stereopsis.

PubMed

Cao, Yongqiang; Grossberg, Stephen

2005-01-01

A laminar cortical model of stereopsis and 3D surface perception is developed and simulated. The model describes how monocular and binocular oriented filtering interact with later stages of 3D boundary formation and surface filling-in in the LGN and cortical areas V1, V2, and V4. It proposes how interactions between layers 4, 3B, and 2/3 in V1 and V2 contribute to stereopsis, and how binocular and monocular information combine to form 3D boundary and surface representations. The model includes two main new developments: (1) It clarifies how surface-to-boundary feedback from V2 thin stripes to pale stripes helps to explain data about stereopsis. This feedback has previously been used to explain data about 3D figure-ground perception. (2) It proposes that the binocular false match problem is subsumed under the Gestalt grouping problem. In particular, the disparity filter, which helps to solve the correspondence problem by eliminating false matches, is realized using inhibitory interneurons as part of the perceptual grouping process by horizontal connections in layer 2/3 of cortical area V2. The enhanced model explains all the psychophysical data previously simulated by Grossberg and Howe (2003), such as contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, Panum's limiting case, the Venetian blind illusion, stereopsis with polarity-reversed stereograms, and da Vinci stereopsis. It also explains psychophysical data about perceptual closure and variations of da Vinci stereopsis that previous models cannot yet explain.

Impact of examinees' stereopsis and near visual acuity on laparoscopic virtual reality performance.

PubMed

Hoffmann, Henry; Ruiz-Schirinzi, Rebecca; Goldblum, David; Dell-Kuster, Salome; Oertli, Daniel; Hahnloser, Dieter; Rosenthal, Rachel

2015-10-01

Laparoscopic surgery represents specific challenges, such as the reduction of a three-dimensional anatomic environment to two dimensions. The aim of this study was to investigate the impact of the loss of the third dimension on laparoscopic virtual reality (VR) performance. We compared a group of examinees with impaired stereopsis (group 1, n = 28) to a group with accurate stereopsis (group 2, n = 29). The primary outcome was the difference between the mean total score (MTS) of all tasks taken together and the performance in task 3 (eye-hand coordination), which was a priori considered to be the most dependent on intact stereopsis. The MTS and performance in task 3 tended to be slightly, but not significantly, better in group 2 than in group 1 [MTS: -0.12 (95 % CI -0.32, 0.08; p = 0.234); task 3: -0.09 (95 % CI -0.29, 0.11; p = 0.385)]. The difference of MTS between simulated impaired stereopsis between group 2 (by attaching an eye patch on the adominant eye in the 2nd run) and the first run of group 1 was not significant (MTS: p = 0.981; task 3: p = 0.527). We were unable to demonstrate an impact of impaired examinees' stereopsis on laparoscopic VR performance. Individuals with accurate stereopsis seem to be able to compensate for the loss of the third dimension in laparoscopic VR simulations.

Novel Retinal Lesion in Ebola Survivors, Sierra Leone, 2016

PubMed Central

Scott, Janet T.; Baxter, Julia M.; Parkes, Craig K.; Dwivedi, Rahul; Czanner, Gabriela; Vandy, Matthew J.; Momorie, Fayiah; Fornah, Alimamy D.; Komba, Patrick; Richards, Jade; Sahr, Foday; Beare, Nicholas A.V.; Semple, Malcolm G.

2017-01-01

We conducted a case–control study in Freetown, Sierra Leone, to investigate ocular signs in Ebola virus disease (EVD) survivors. A total of 82 EVD survivors with ocular symptoms and 105 controls from asymptomatic civilian and military personnel and symptomatic eye clinic attendees underwent ophthalmic examination, including widefield retinal imaging. Snellen visual acuity was <6/7.5 in 75.6% (97.5% CI 63%–85.7%) of EVD survivors and 75.5% (97.5% CI 59.1%–87.9%) of controls. Unilateral white cataracts were present in 7.4% (97.5% CI 2.4%–16.7%) of EVD survivors and no controls. Aqueous humor from 2 EVD survivors with cataract but no anterior chamber inflammation were PCR-negative for Zaire Ebola virus, permitting cataract surgery. A novel retinal lesion following the anatomic distribution of the optic nerve axons occurred in 14.6% (97.5% CI 7.1%–25.6%) of EVD survivors and no controls, suggesting neuronal transmission as a route of ocular entry. PMID:28628441

Novel Retinal Lesion in Ebola Survivors, Sierra Leone, 2016.

PubMed

Steptoe, Paul J; Scott, Janet T; Baxter, Julia M; Parkes, Craig K; Dwivedi, Rahul; Czanner, Gabriela; Vandy, Matthew J; Momorie, Fayiah; Fornah, Alimamy D; Komba, Patrick; Richards, Jade; Sahr, Foday; Beare, Nicholas A V; Semple, Malcolm G

2017-07-01

We conducted a case-control study in Freetown, Sierra Leone, to investigate ocular signs in Ebola virus disease (EVD) survivors. A total of 82 EVD survivors with ocular symptoms and 105 controls from asymptomatic civilian and military personnel and symptomatic eye clinic attendees underwent ophthalmic examination, including widefield retinal imaging. Snellen visual acuity was <6/7.5 in 75.6% (97.5% CI 63%-85.7%) of EVD survivors and 75.5% (97.5% CI 59.1%-87.9%) of controls. Unilateral white cataracts were present in 7.4% (97.5% CI 2.4%-16.7%) of EVD survivors and no controls. Aqueous humor from 2 EVD survivors with cataract but no anterior chamber inflammation were PCR-negative for Zaire Ebola virus, permitting cataract surgery. A novel retinal lesion following the anatomic distribution of the optic nerve axons occurred in 14.6% (97.5% CI 7.1%-25.6%) of EVD survivors and no controls, suggesting neuronal transmission as a route of ocular entry.

Cataract in children attending schools for the blind and resource centers in eastern Africa.

PubMed

Msukwa, Gerald; Njuguna, Margaret; Tumwesigye, Cillasy; Shilio, Bernadeth; Courtright, Paul; Lewallen, Susan

2009-05-01

The aim of this study was to describe results of a representative sample of children who have undergone cataract surgery in schools for the blind in 4 African countries. Cross-sectional study. Children enrolled at schools for the blind in Kenya, Malawi, Tanzania, and Uganda. We used a population-proportional-to-size methodology to select a representative sample of schools for the blind and annexes and included all the children attending the selected schools. Trained teams using standardized examination methods and a modified World Health Organization form examined the children. The form was modified specifically to collect information on outcomes of cataract surgery. Operative status and postoperative visual acuity. Of 1062 children examined, 196 (18%) had undergone cataract surgery or had cataract as the major cause of visual impairment; 140 (71%) had bilateral surgery, 24 (12%) had unilateral surgery, and 32 (16%) had not had surgery. Of operated eyes, 118 (41%) had visual acuity > or =20/200. Intraocular lenses were implanted in 65% of the operated eyes. Eyes with intraocular lens were more likely to have better vision than those without (P for trend = 0.04). Amblyopia was the most common cause of poor visual acuity in children who had undergone cataract surgery. The number of children in the schools who receive cataract surgery has increased greatly since 1995. The high rate of amblyopia highlights the critical need for programs to find children earlier and to ensure adequate follow-up after surgery. Without such programs, the value of training pediatric surgeons will not be fully realized. The authors have no proprietary or commercial interest in any materials discussed in this article.

High lenticular tolerance to ultraviolet radiation-B by pigmented guinea-pig; application of a safety limit strategy for UVR-induced cataract.

PubMed

Mody, Vino C; Kakar, Manoj; Söderberg, Per G; Löfgren, Stefan

2012-05-01

The purpose of this study was to determine a threshold measure, maximum tolerable dose (MTD), for avoidance of UVR-B-induced cataract in the pigmented guinea-pig. Thirty pupil-dilated anesthetized young female guinea-pigs, divided into five equal groups, received between 0 and 84.9 kJ/m(2) unilateral UVR-B. Lens extraction and in vitro lens photography occurred 24 hr after exposure. Measurement of intensity of lens light scattering served as quantifying tool for the degree of cataract. Data analysis included regression, using a second order polynomial model. The applied MTD concept was based on the UVR-B dose-response curve obtained for the pigmented guinea-pig. A smaller number of pigmented guinea-pigs, pigmented rats and albino rats underwent morphometric analysis of the anterior segment geometry. All eyes exposed to UVR-B developed cataract in the anterior subcapsular region. MTD for avoidance of UVR-B-induced cataract was 69.0 kJ/m(2) in the pigmented guinea-pig. Iris was considerably thicker in the guinea-pig than in the rats. Lens blockage by the dilated iris was lowest in the guinea-pig. Maximum tolerable dose for avoidance of UVR-B-induced cataract in the pigmented guinea-pig was 69.0 kJ/m(2), over 10-fold higher than the threshold 5 kJ/m(2) obtained by Pitts et al. in the pigmented rabbit. Maximum tolerable dose is an appropriate method for estimation of toxicity for UVR-B-induced cataract in the guinea-pig. The pigmented guinea-pig is significantly less sensitive to UVR-B exposure than the pigmented rabbit and pigmented rat. © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

New Perspectives in Amblyopia Therapy on Adults: A Critical Role for the Excitatory/Inhibitory Balance

PubMed Central

Baroncelli, Laura; Maffei, Lamberto; Sale, Alessandro

2011-01-01

Amblyopia is the most common form of impairment of visual function affecting one eye, with a prevalence of about 1–5% of the total world population. This pathology is caused by early abnormal visual experience with a functional imbalance between the two eyes owing to anisometropia, strabismus, or congenital cataract, resulting in a dramatic loss of visual acuity in an apparently healthy eye and various other perceptual abnormalities, including deficits in contrast sensitivity and in stereopsis. It is currently accepted that, due to a lack of sufficient plasticity within the brain, amblyopia is untreatable in adulthood. However, recent results obtained both in clinical trials and in animal models have challenged this traditional view, unmasking a previously unsuspected potential for promoting recovery after the end of the critical period for visual cortex plasticity. These studies point toward the intracortical inhibitory transmission as a crucial brake for therapeutic rehabilitation and recovery from amblyopia in the adult brain. PMID:22144947

Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis

PubMed Central

Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

2015-01-01

The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

Anterior segment optical coherence tomography parameters in phacomorphic angle closure and mature cataracts.

PubMed

Mansouri, Mohammadreza; Ramezani, Farshid; Moghimi, Sasan; Tabatabaie, Ali; Abdi, Fatemeh; He, Mingguang; Lin, Shan C

2014-10-21

To describe anterior segment optical coherence tomography (AS-OCT) parameters in phacomorphic angle closure eyes, mature cataract eyes, and their fellow eyes, and identify those parameters that could be used to differentiate phacomorphic angle closure eyes from those with mature cataract and no phacomorphic angle closure. In this cross-sectional study, a total of 33 phacomorphic angle closure subjects and 34 control patients with unilateral mature cataracts were enrolled. All patients underwent AS-OCT imaging and A-scan biometry of both eyes. Anterior chamber depth (ACD), anterior chamber area (ACA), iris thickness, iris curvature, lens vault (LV), and angle parameters, including angle opening distance (AOD750) and trabecular-iris space area (TISA750), were measured in qualified images using customized software and compared among eyes with phacomorphic angle closure, mature cataract eyes, and their fellow eyes. There was no significant difference in axial length among the four groups. Phacomorphic angle closure had the smallest angle (AOD750, TISA750) and anterior chamber parameters (ACD, ACA, anterior chamber width) and the greatest LV among the groups. This pattern was similar when comparing fellow eyes of mature cataract patients and fellow eyes of phacomorphic angle closure. Anterior chamber area less than 18.62 mm(2), ACD less than 2.60 mm, LV greater than 532.0 μm, and AOD750 less than 0.218 mm had the highest odds ratios (ORs) for distinguishing fellow eyes of phacomorphic angle closure versus fellow eyes of mature cataracts, with OR values of 9.90, 8.31, 7.91, and 7.91, respectively. Logistic regression showed that ACA less than 18.62 was the major parameter associated with fellow eyes of phacomorphic angle closure (OR = 10.96, P < 0.001). Anterior chamber depth, ACA, AOD750, and LV are powerful indicators in differentiating phacomorphic angle closure eyes from those with mature cataract and their fellow eyes. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Post-Cataract Surgery Optic Neuropathy: Prevalence, Incidence, Temporal Relationship, and Fellow Eye Involvement.

PubMed

Moradi, Ahmadreza; Kanagalingam, Sivashakthi; Diener-West, Marie; Miller, Neil R

2017-03-01

To reassess the prevalence and incidence of post-cataract surgery optic neuropathy (PCSON) in the modern era. Retrospective cohort study. Setting: Single-center tertiary care practice. All patients with a diagnosis of nonarteritic anterior ischemic optic neuropathy (NAION) seen in the Wilmer Eye Network system between January 1, 2010 and December 31, 2014 were included. Inclusion was based on the following: (1) a history of an acute unilateral decrease in vision, (2) a visual field defect consistent with NAION, (3) a relative afferent pupillary defect, (4) observed optic disc swelling, and (5) no other etiology being found. The prevalence and incidence of PCSON and the temporal association between surgery and onset of PCSON. The secondary outcome was the risk of PCSON in the fellow eye of patients with prior unilateral spontaneous NAION. One hundred eighty-eight patients had developed NAION during the study period. Of these, 18 (9.6%) had undergone cataract surgery (CS) during the year prior to developing NAION. There was no significant temporal pattern associated with the distribution of NAION cases (P = .28). The incidence of PCSON in patients who had noncomplex CS was 10.9 cases per 100 000 (95% CI, 1.3, 39.4). Our data indicate that both the prevalence and incidence of NAION after modern CS are comparable to those of the general population and that there is no significant temporal relationship between modern CS and the subsequent development of NAION in the operated eye. Thus, although this study has inherent biases owing to its retrospective nature, concern regarding an increased risk of PCSON in the fellow eye in patients who have experienced it or spontaneous NAION in 1 eye may be unwarranted. Copyright © 2016 Elsevier Inc. All rights reserved.

Sensorial status in patients with pure accomodative esotropia.

PubMed

Castro-Vite, O I; Vargas-Ortega, A J; Aguilar-Ruiz, A; Murillo-Correa, C E

2016-12-01

To evaluate the sensorial status in patients with pure accommodative esotropia. Ambispective study, patients with pure accommodative esotropia that were found in orthotropy when using its correction glasses were included. 67 patients were included, mean age was 3.68±1.28 years, the near and far ocular deviation was 19±8.8 PD and 18.71±10.61 PD respectively. The visual acuity in the right eye was 0.183 ±0.11 logMAR, in the left eye was 0.188±0.12 logMAR. The average spherical equivalent was +5.50 diopters, for the right eye was +5.46 ±1.61 diopters and for the left eye +5.71 v±1.6 diopters. The average AC/A ratio was 5.19±0.92 Δ/1. 90% of the patients had a grade of near stereopsis: 42% had stereopsis equal or better to 70 arc seconds and 81% had stereopsis equal or better to 400 arc seconds, having an average of 205 arc seconds. 85% of the patients had some grade of far stereopsis: 16% had stereopsis equal or better to 70 arc seconds and 66% had a stereopsis equal or better to 400 arc seconds, having an average of 334.9 arc seconds. There was not statistically significant correlation between the grade of deviation and the stereopsis when using its correction. This study has detected that the sensorial status is compromised even with adequate and appropriate treatment, nevertheless, there is a low frequency of amblyopia. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Solving da Vinci stereopsis with depth-edge-selective V2 cells

PubMed Central

Assee, Andrew; Qian, Ning

2007-01-01

We propose a new model for da Vinci stereopsis based on a coarse-to-fine disparity-energy computation in V1 and disparity-boundary-selective units in V2. Unlike previous work, our model contains only binocular cells, relies on distributed representations of disparity, and has a simple V1-to-V2 feedforward structure. We demonstrate with random dot stereograms that the V2 stage of our model is able to determine the location and the eye-of-origin of monocularly occluded regions and improve disparity map computation. We also examine a few related issues. First, we argue that since monocular regions are binocularly defined, they cannot generally be detected by monocular cells. Second, we show that our coarse-to-fine V1 model for conventional stereopsis explains double matching in Panum’s limiting case. This provides computational support to the notion that the perceived depth of a monocular bar next to a binocular rectangle may not be da Vinci stereopsis per se (Gillam et al., 2003). Third, we demonstrate that some stimuli previously deemed invalid have simple, valid geometric interpretations. Our work suggests that studies of da Vinci stereopsis should focus on stimuli more general than the bar-and-rectangle type and that disparity-boundary-selective V2 cells may provide a simple physiological mechanism for da Vinci stereopsis. PMID:17698163

da Vinci decoded: does da Vinci stereopsis rely on disparity?

PubMed

Tsirlin, Inna; Wilcox, Laurie M; Allison, Robert S

2012-11-01

In conventional stereopsis, the depth between two objects is computed based on the retinal disparity in the position of matching points in the two eyes. When an object is occluded by another object in the scene, so that it is visible only in one eye, its retinal disparity cannot be computed. Nakayama and Shimojo (1990) found that a precept of quantitative depth between the two objects could still be established for such stimuli and proposed that this precept is based on the constraints imposed by occlusion geometry. They named this and other occlusion-based depth phenomena "da Vinci stereopsis." Subsequent research found quantitative depth based on occlusion geometry in several other classes of stimuli grouped under the term da Vinci stereopsis. However, Nakayama and Shimojo's findings were later brought into question by Gillam, Cook, and Blackburn (2003), who suggested that quantitative depth in their stimuli was perceived based on conventional disparity. In order to understand whether da Vinci stereopsis relies on one type of mechanism or whether its function is stimulus dependent we examine the nature and source of depth in the class of stimuli used by Nakayama and Shimojo (1990). We use three different psychophysical and computational methods to show that the most likely source for depth in these stimuli is occlusion geometry. Based on these experiments and previous data we discuss the potential mechanisms responsible for processing depth from monocular features in da Vinci stereopsis.

Drinking water supplementation with ascorbate is not protective against UVR-B-induced cataract in the guinea pig.

PubMed

Mody, Vino C; Kakar, Manoj; Elfving, Ase; Löfgren, Stefan

2008-03-01

To study if ascorbate supplementation decreases ultraviolet radiation (UVR)-induced cataract development in the guinea pig. Sixty 6-9-week-old pigmented guinea pigs received drinking water supplemented with or without 5.5 mm l-ascorbate for 4 weeks. After supplementation, 40 animals were exposed unilaterally in vivo under anaesthesia to 80 kJ/m(2) UVR-B. One day later, the animals were killed and lenses were extracted. Degree of cataract was quantified by measurement of intensity of forward lens light scattering. Lens ascorbate concentration was determined with high-performance liquid chromatography (HPLC) with UVR detection at 254 nm. Twenty animals were used as non-exposed control. Supplementation increased lens ascorbate concentration significantly. In UVR-exposed animals, mean 95% confidence intervals (CIs) for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.54 +/- 0.07 (no ascorbate) and 0.83 +/- 0.05 (5.5 mm ascorbate). In non-exposed control animals, mean 95% CIs for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.72 +/- 0.12 (0 mm ascorbate) and 0.90 +/- 0.15 (5.5 mm ascorbate). All non-exposed lenses were devoid of cataract. Superficial anterior cataract developed in all UVR-exposed lenses. The lens light scattering was 39.2 +/- 14.1 milli transformed equivalent diazepam concentration (m(tEDC)) without and 35.9 +/- 14.0 m(tEDC) with ascorbate supplementation. Superficial anterior cataract develops in lenses exposed to UVR-B. Ascorbate supplementation is non-toxic to both UVR-B-exposed lenses and non-exposed control lenses. Ascorbate supplementation does not reduce in vivo lens forward light scattering secondary to UVR-B exposure in the guinea pig.

A three dimensional view of stereopsis in dentistry.

PubMed

Mon-Williams, M A; Mushtaq, F; Wilkie, R M; Khambay, B; Keeling, A; Manogue, M

2015-11-27

Stereopsis and its role in dental practice has been a topic of debate in recent editions of this Journal. These discussions are particularly timely as they come at a point when virtual reality simulators are becoming increasingly popular in the education of tomorrow's dentists. The aim of this article is to discuss the lack of robust empirical evidence to ascertain the relationship (if any) between stereopsis and dentistry and to build a case for the need for further research to build a strong evidence base on the topic.

Ultraviolet radiation exposure triggers neurokinin-1 receptor upregulation in ocular tissues in vivo.

PubMed

Gross, Janine; Wegener, Alfred R; Kronschlaeger, Martin; Holz, Frank G; Schönfeld, Carl-Ludwig; Meyer, Linda M

2018-04-26

The purpose of this study was to investigate the neurokinin receptor-1 (NKR-1) protein expression in ocular tissues before and after supra-cataract threshold ultraviolet radiation (UVR-B peak at 312 nm) exposure in vivo in a mouse model. Six-week-old C57Bl/6 mice were unilaterally exposed to a single (2.9 kJ/m 2 ) and an above 3-fold UVR-B cataract threshold dose (9.4 kJ/m 2 ) of UVR. UVR-exposure (λpeak = 312 nm) was performed in mydriasis using a Bio-Spectra exposure system. After latency periods of 3 and 7 days, eyes were fixed in 4% paraformaldehyde, embedded in paraffin, sectioned and stained with fluorescence coupled antibody for NKR-1 and DAPI for cell nuclei staining. Control animals received only anesthesia but no UVR-exposure. Cataract development was documented with a Leica dark-field microscope and quantified as integrated optical density (IOD). NKR-1 is ubiquitously present in ocular tissues. An above 3-fold cataract threshold dose of UV-radiation induced NKR-1 upregulation after days 3 and 7 in the epithelium and endothelium of the cornea, the endothelial cells of the iris vessels, the pigmented epithelium/stroma of the ciliary body, the lens epithelium, pronounced in the nuclear bow region and the inner plexiform layer of the retina. A significant upregulation of NKR-1 could not be provoked with a single cataract threshold dose (2.9 kJ/m 2 UVR-B) ultraviolet irradiation. All exposed eyes developed anterior subcapsular cataracts. Neurokinin-1 receptor is present ubiquitously in ocular tissues including the lens epithelium and the nuclear bow region of the lens. UV-radiation exposure to an above 3-fold UVR-B cataract threshold dose triggers NKR-1 upregulation in the eye in vivo. The involvement of inflammation in ultraviolet radiation induced cataract and the role of neuroinflammatory peptides such as substance P and its receptor, NKR-1, might have been underestimated to date. Copyright © 2018. Published by Elsevier Ltd.

Visual function among commercial vehicle drivers in the central region of Ghana

PubMed Central

Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

2015-01-01

Aim To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. Method A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. Results 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02 ± 0.08 logMAR. Protans were more likely to be involved in RTAs (χ2 = 6.194, p = 0.034). However, there was no statistically significant association between abnormal stereopsis (OR = 0.89 95% CI: 0.44–1.80, p = 0.56), poor vision due to refractive error (χ2 = 3.090, p = 0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r = 0.371, p < 0.005). Conclusion The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. PMID:26364760

Visual function among commercial vehicle drivers in the central region of Ghana.

PubMed

Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

2016-01-01

To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02±0.08 logMAR. Protans were more likely to be involved in RTAs (χ(2)=6.194, p=0.034). However, there was no statistically significant association between abnormal stereopsis (OR=0.89 95% CI: 0.44-1.80, p=0.56), poor vision due to refractive error (χ(2)=3.090, p=0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r=0.371, p<0.005). The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Stereopsis and fusion in anisometropia according to the presence of amblyopia.

PubMed

Jeon, Hyun Sun; Choi, Dong Gyu

2017-12-01

To evaluate the level of stereopsis and fusion in patients with anisometropia according to the presence of amblyopia. We included 107 children with anisometropia, divided into groups with non-amblyopic anisometropia (NA, n = 72) and amblyopic anisometropia (AA, n = 35). Normal subjects without anisometropia were enrolled in the control group (n = 73). Main outcome measures were the level of stereopsis and sensory fusion as evaluated by Titmus stereotest and Worth 4-dot test, respectively, using anisometropic glasses. The degree of anisometropia in the NA, AA, and control groups was 2.54 diopters (D), 4.29 D, and 0.30 D, respectively (P = 0.014). Stereopsis (arcsec) was significantly worse in the AA group than the NA and control groups (641.71, 76.25, 54.52, respectively, P < 0.001), while no significant difference was found between the NA and control groups. The rate of fusion was significantly lower in the AA than the NA group (14.3% vs. 65.3%, P < 0.001), and was significantly lower in the NA than the control group (65.3% vs. 80.6%, P = 0.001). The levels of stereopsis and sensory fusion with anisometropic glasses were significantly worse in the AA than in the NA group. The level of stereopsis in the NA group, however, did not differ significantly from that in the isometropic control, while the rate of fusion was significantly lower. Early prescription of anisometropic glasses is needed to improve visual acuity and binocularity in children with possible amblyopic anisometropia.

The role of transparency in da Vinci stereopsis.

PubMed

Zannoli, Marina; Mamassian, Pascal

2011-10-15

The majority of natural scenes contains zones that are visible to one eye only. Past studies have shown that these monocular regions can be seen at a precise depth even though there are no binocular disparities that uniquely constrain their locations in depth. In the so-called da Vinci stereopsis configuration, the monocular region is a vertical line placed next to a binocular rectangular occluder. The opacity of the occluder has been mentioned to be a necessary condition to obtain da Vinci stereopsis. However, this opacity constraint has never been empirically tested. In the present study, we tested whether da Vinci stereopsis and perceptual transparency can interact using a classical da Vinci configuration in which the opacity of the occluder varied. We used two different monocular objects: a line and a disk. We found no effect of the opacity of the occluder on the perceived depth of the monocular object. A careful analysis of the distribution of perceived depth revealed that the monocular object was perceived at a depth that increased with the distance between the object and the occluder. The analysis of the skewness of the distributions was not consistent with a double fusion explanation, favoring an implication of occlusion geometry in da Vinci stereopsis. A simple model that includes the geometry of the scene could account for the results. In summary, the mechanism responsible to locate monocular regions in depth is not sensitive to the material properties of objects, suggesting that da Vinci stereopsis is solved at relatively early stages of disparity processing. Copyright © 2011 Elsevier Ltd. All rights reserved.

Device for diagnosis and treatment of impairments on binocular vision and stereopsis

NASA Astrophysics Data System (ADS)

Bahn, Jieun; Choi, Yong-Jin; Son, Jung-Young; Kodratiev, N. V.; Elkhov, Victor A.; Ovechkis, Yuri N.; Chung, Chan-sup

2001-06-01

Strabismus and amblyopia are two main impairments of our visual system, which are responsible for the loss of stereovision. A device is developed for diagnosis and treatment of strabismus and amblyopia, and for training and developing stereopsis. This device is composed of a liquid crystal glasses (LCG), electronics for driving LCG and synchronizing with an IBM PC, and a special software. The software contains specially designed patterns and graphics for enabling to train and develop stereopsis, and do objective measurement of some stereoscopic vision parameters such as horizontal and vertical phoria, fusion, fixation disparity, and stereoscopic visual threshold.

Interactions between chromatic- and luminance-contrast-sensitive stereopsis mechanisms.

PubMed

Simmons, David R; Kingdom, Frederick A A

2002-06-01

It is well known that chromatic information can assist in solving the stereo correspondence problem. It has also been suggested that there are two independent first-order stereopsis mechanisms, one sensitive to chromatic contrast and the other sensitive to luminance contrast (Vision Research 37 (1997) 1271). Could the effect of chromatic information on stereo correspondence be subserved by interactions between these mechanisms? To address this question, disparity thresholds (1/stereoacuity) were measured using 0.5 cpd Gabor patches. The stimuli possessed different relative amounts of chromatic and luminance contrast which could be correlated or anti-correlated between the eyes. Stereoscopic performance with these compound stimuli was compared to that with purely isoluminant and isochromatic stimuli at different contrasts. It was found that anti-correlated chromatic contrast severely disrupted stereopsis with achromatic stimuli and that anti-correlated luminance contrast severely disrupted stereopsis with chromatic stimuli. Less dramatic, but still significant, was the improvement in stereoacuity obtained using correlated colour and luminance contrast. These data are consistent with there being positive and negative interactions between chromatic and achromatic stereopsis mechanisms that take place after the initial encoding of disparity information, but before the extraction of stereoscopic depth. These interactions can be modelled satisfactorily assuming probability summation of depth sign information between independent mechanisms.

Ophthalmological abnormalities in wild European hedgehogs (Erinaceus europaeus): a survey of 300 animals

PubMed Central

Williams, David; Adeyeye, Nina; Visser, Erni

2017-01-01

In this study we aimed to examine wild European hedgehogs (Erinaceus europaeus) in rescue centres and to determine ocular abnormalities in this animal population. Three hundred animals varying in age from 2 months to 5 years were examined, 147 being male and 153 female. All animals were evaluated with direct and indirect ophthalmoscopy and slit lamp biomicroscopy in animals where lesions were detected. Tonometry using the Tonovet rebound tonometer was undertaken in selected animals as was assessment of tear production using the Schirmer I tear test. Four animals were affected by orbital infection, 3 were anophthalmic, 2 unilaterally and one bilaterally, 3 by conjunctivitis, 3 by non-ulcerative keratitis and 4 by uveitis with corneal oedema. Fifty seven animals were affected by cataract, 54 with bilateral nuclear lens opacities. Twenty six of these animals were young animals considered too small to hibernate. This report documents the first prospective study of ocular disease in the European hedgehog. The predominant finding was bilateral nuclear cataract seen particularly in young poorly growing animals. Investigation into the potential causation of cataracts by poor nutrition or poor feeding ability by lens opacification requires further study. PMID:29038778

Stereopsis testing without polarized glasses: a comparison study on five new stereoacuity tests.

PubMed

Hatch, S W; Richman, J E

1994-09-01

Stereopsis testing is commonly used to assess the presence and level of binocular vision. A new series of stereopsis tests requiring no polarized goggles are available in the form of the Titmus Stereo Test, the Stereo Reindeer Test, the Random Dot Butterfly, the Random Dot Figures, and the Random E, Circle, Square. These polarized-free tests employ a special prismatic printing process creating a panagraphic presentation, i.e., a separate image is presented to each eye without the need for polarization. The purpose of this study was to compare the polarized-free stereo tests with their traditional polarized counterparts. Thirty four subjects, including several persons with strabismus, ages 10-35 years, were each tested with the polarized and polarized-free versions of the Titmus, Reindeer, Butterfly, and Figures. Twenty nine of these subjects were tested with the Random Dot E. Half the subjects were tested first with polarized-free and half were tested first with polarized tests. Tests were performed according to manufacturer instructions by the same examiner in clinical settings. The results (matched pair ranked correlation coefficients) indicate that the polarized-free tests were highly correlated (r = 0.997, r = 0.998, r = 0.997, r = 1.00, and r = 1.00 respectively) with the polarized comparison tests. No significant difference (Wilcoxon Ranked Sign) in the stereopsis level was obtained between the two versions of the tests. We conclude that these five polarized-free tests were just as valid in measuring the subjects' stereopsis as their traditional polarized version. The use of goggle-free testing has potential clinical advantages, e.g., testing of young children who will not wear the glasses or the improved observation of the ocular alignment during stereopsis testing.

Early light deprivation effects on human cone-driven retinal function.

PubMed

Esposito Veneruso, Paolo; Ziccardi, Lucia; Magli, Giulia; Parisi, Vincenzo; Falsini, Benedetto; Magli, Adriano

2017-03-01

To assess whether the early light deprivation induced by congenital cataract may influence the cone-driven retinal function in humans. Forty-one patients affected by congenital cataract (CC) who had undergone uncomplicated cataract extraction surgery and intraocular lens implant, and 14 healthy subjects (HS) were enrolled. All patients underwent complete ophthalmological and orthoptic evaluations and best-corrected visual acuity (BCVA) measurement; light-adapted full-field electroretinograms (ERG) and photopic negative responses (PhNR) were recorded to obtain a reliable measurement of the outer/inner retinal function and of the retinal ganglion cells' function respectively. Mean values of light-adapted ERG a- and b-wave and PhNR amplitude of CC eyes were significantly reduced and photopic ERG b-wave implicit time mean values were significantly delayed when compared to HS ones. When studying photopic ERG mean amplitudes at 5 ms, significant differences were found when comparing CC and control eyes. In CC eyes, statistically significant correlations were found between a- and b- wave amplitudes and PhNR amplitudes. No significant correlations were found between ERG parameters and BCVA, as well as between the age of CC patients at surgery and the time elapsed from lens extraction. No significant differences were found when functional parameters of bilateral and unilateral congenital cataract (uCC) eyes were compared, however uCC eyes showed significant differences when compared with contralateral healthy eyes. We found a significant impairment of cone-driven retinal responses in patients with a history of congenital cataract. These changes might result from the long-lasting effects of early light deprivation on the cone retinal pathways. Our findings support the relevance of retinal involvement in deficits induced by early light deprivation. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Caffeine Eye Drops Protect Against UV-B Cataract

PubMed Central

Kronschläger, Martin; Löfgren, Stefan; Yu, Zhaohua; Talebizadeh, Nooshin; Varma, Shambhu D.; Söderberg, Per

2013-01-01

The purpose of this study was to investigate if topically applied caffeine protects against in vivo ultraviolet radiation cataract and if so, to estimate the protection factor. Three experiments were carried out. First, two groups of Sprague-Dawley rats were pre-treated with a single application of either placebo or caffeine eye drops in both eyes. All animals were then unilaterally exposed in vivo to 8 kJ/m2 UV-B radiation for 15 min. One week later, the lens GSH levels were measured and the degree of cataract was quantified by measurement of in vitro lens light scattering. In the second experiment, placebo and caffeine pre-treated rats were divided in five UV-B radiation dose groups, receiving 0.0, 2.6, 3.7, 4.5 or 5.2 kJ/m2 UV-B radiation in one eye. Lens light scattering was determined after one week. In the third experiment, placebo and caffeine pre-treated rats were UV-B-exposed and the presence of activated caspase-3 was visualized by immunohistochemistry. There was significantly less UV-B radiation cataract in the caffeine group than in the placebo group (95% confidence interval for mean difference in lens light scattering between the groups = 0.10 ± 0.05 tEDC), and the protection factor for caffeine was 1.23. There was no difference in GSH levels between the placebo- and the caffeine group. There was more caspase-3 staining in UV-B-exposed lenses from the placebo group than in UV-B-exposed lenses from the caffeine group. Topically applied caffeine protects against ultraviolet radiation cataract, reducing lens sensitivity 1.23 times. PMID:23644096

Immediate sequential bilateral cataract surgery: A 5-year retrospective analysis of 2470 eyes from a tertiary care eye center in South India

PubMed Central

Ganesh, Sri; Brar, Sheetal; Sreenath, Rohit

2017-01-01

Purpose: The purpose of this study is to evaluate the safety and benefits of immediate sequential bilateral cataract surgery. Patients and Methods: Retrospective data analysis of patients who underwent immediate sequential bilateral phacoemulsification with foldable intraocular lens (IOL) implantation under topical anesthesia from January 2011 to September 2016 was performed. Patients with visually significant bilateral cataract within the axial length range of 21.0–26.5 mm were included in the study. Intraoperative and postoperative complications were evaluated. Results: Two thousand four hundred and seventy eyes from 1235 patients with a mean age of 68.34 years (range: 4–90 years) were analyzed. Best-corrected visual acuity improved from 0.40 ± 0.17 to 0.08 ± 0.10 (logarithm of the minimum angle of resolution). Nearly 92.05% eyes achieved a target postoperative refraction of ± 0.5 D spherical equivalent. Main complications observed were prolonged postoperative inflammation in 25% (n = 31), posterior capsular tears in 0.45% (n = 11), and unilateral cystoid macular edema in 0.08% (n = 2) eyes. No sight-threatening complications such as endophthalmitis, retinal detachment, corneal decompensation and intraocular hemorrhage occurred in any of the eyes. Out of the 288 (23.2%) patients who underwent bilateral multifocal IOL implantation, 23 patients (46 eyes) had femtolaser-assisted cataract surgery procedure. Two pediatric and one Downs syndrome patient underwent bilateral cataract surgery under general anesthesia and intravenous sedation, respectively. Conclusion: IBSCS may be considered as a preferred practice in eligible cases considering significant patient benefits such as early visual rehabilitation, time and cost-effectiveness, and better compliance with postoperative medications. In debilitated patients and special situations, such as pediatric cataract and Downs syndrome requiring general anesthesia it may be the ideal procedure. PMID:28573990

Rasch analysis of the hospital anxiety and depression scale among Chinese cataract patients.

PubMed

Lin, Xianchai; Chen, Ziyan; Jin, Ling; Gao, Wuyou; Qu, Bo; Zuo, Yajing; Liu, Rongjiao; Yu, Minbin

2017-01-01

To analyze the validity of the Hospital Anxiety and Depression Scale (HADS) among Chinese cataract population. A total of 275 participants with unilateral or bilateral cataract were recruited to complete the Chinese version of HADS. The patients' demographic and ophthalmic characteristics were documented. Rasch analysis was conducted to examine the model fit statistics, the thresholds ordering of the polytomous items, targeting, person separation index and reliability, local dependency, unidimentionality, differential item functioning (DIF) and construct validity of the HADS individual and summary measures. Rasch analysis was performed on anxiety and depression subscales as well as HADS-Total score respectively. The items of original HADS-Anxiety, HADS-Depression and HADS-Total demonstrated evidence of misfit of the Rasch model. Removing items A7 for anxiety subscale and rescoring items D14 for depression subscale significantly improved Rasch model fit. A 12-item higher order total scale with further removal of D12 was found to fit the Rasch model. The modified items had ordered response thresholds. No uniform DIF was detected, whereas notable non-uniform DIF in high-ability group was found. The revised cut-off points were given for the modified anxiety and depression subscales. The modified version of HADS with HADS-A and HADS-D as subscale and HADS-T as a higher-order measure is a reliable and valid instrument that may be useful for assessing anxiety and depression states in Chinese cataract population.

Clinically Normal Stereopsis Does Not Ensure Performance Benefit from Stereoscopic 3D Depth Cues

DTIC Science & Technology

2014-10-28

Stereopsis, Binocular Vision, Optometry , Depth Perception, 3D vision, 3D human factors, Stereoscopic displays, S3D, Virtual environment 16...Binocular Vision, Optometry , Depth Perception, 3D vision, 3D human factors, Stereoscopic displays, S3D, Virtual environment 1 Distribution A: Approved

Association of Radiation Dose to the Eyes With the Risk for Cataract After Nonretinoblastoma Solid Cancers in Childhood.

PubMed

Allodji, Rodrigue S; Diallo, Ibrahima; El-Fayech, Chiraz; Kahlouche, Amar; Dumas, Agnès; Schwartz, Boris; Oberlin, Odile; Benadjaoud, Mohamed Amine; Labbé, Martine; Jackson, Angela; Bullet, Julien; Rubino, Carole; Haddy, Nadia; De Vathaire, Florent

2016-04-01

Few studies have been published on the association of the radiation dose received to the eyes during radiotherapy (RT) for childhood cancer and the risk for later cataract. To investigate the risk for cataract after treatment of nonretinoblastoma solid cancer in childhood. The study used data from the Euro2K cohort that includes 4389 5-year survivors of solid tumors treated from January 1, 1945, to December 31, 1985; of these, 3172 patients were treated in France. A self-reported questionnaire was sent to French survivors from September 1, 2005, to December 31, 2012, when follow-up was considered completed for this study. However, 619 patients died before the beginning of the study and 128 patients treated for a retinoblastoma or who underwent enucleation were excluded. Likewise, 429 patients with unknown addresses or who did not return the consent form and 163 nonresponders did not participate. The remaining 1833 patients who completed the questionnaire underwent analysis for this study from June 1, 2014, to December 7, 2015. Radiation doses in both eyes for individuals were estimated for all patients who had received RT. The role of the radiation dose in cataract risk was investigated using the Cox proportional hazard regression model and the excess relative or the absolute risk model. The role of ctytotoxic chemotherapy was also investigated. The 1833 patients (961 men [52.4%]; 872 women [47.6%]; mean [SD] age, 37.0 [8.5]) who returned the questionnaire were included in the analysis. After a mean follow-up of 32 years, 33 patients with unilateral or bilateral cataract were identified, for a total of 47 cataract events. The 47 events were validated by medical record review and by contacting the patients and the corresponding medical physician or ophthalmologist to obtain copies of diagnostic examinations or surgical reports. Overall, in a multivariable Cox proportional hazard regression analysis, patients who received RT had a 4.4-fold (95% CI, 1.5- to 13.0-fold) increased risk for cataract compared with patients who did not receive RT. Exposure to radiation doses of at least 10 Gy to the eyes increased the hazard ratio 39-fold (95% CI, 12.0- to 127.9-fold), relative to no radiation exposure. Although based on few patients, a strong increase in cataract risk (hazard ratio, 26.3; 95% CI, 7.1-96.6) was observed in patients treated with melphalan hydrochloride. This study can inform guideline-based recommendations for long-term follow-up for cataract.

Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced

NASA Astrophysics Data System (ADS)

Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per

2015-01-01

The damage mechanism for near-infrared radiation (IRR) induced cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm2 IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344 kJ/cm2, respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0±1.1, 6.8±1.1, 7.6±1.3, and 7.4±1.1°C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00±0.02, 0.01±0.03, -0.01±0.02, and -0.01±0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm2 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm2 does not induce cataract if the temperature rise at the limbus is <8°C. This is consistent with a thermal damage mechanism for IRR-induced cataract.

Active training for amblyopia in adult rodents

PubMed Central

Sale, Alessandro; Berardi, Nicoletta

2015-01-01

Amblyopia is the most diffused form of visual function impairment affecting one eye, with a prevalence of 1–5% in the total world population. Amblyopia is usually caused by an early functional imbalance between the two eyes, deriving from anisometropia, strabismus, or congenital cataract, leading to severe deficits in visual acuity, contrast sensitivity and stereopsis. While amblyopia can be efficiently treated in children, it becomes irreversible in adults, as a result of a dramatic decline in visual cortex plasticity which occurs at the end of the critical period (CP) in the primary visual cortex. Notwithstanding this widely accepted dogma, recent evidence in animal models and in human patients have started to challenge this view, revealing a previously unsuspected possibility to enhance plasticity in the adult visual system and to achieve substantial visual function recovery. Among the new proposed intervention strategies, non invasive procedures based on environmental enrichment, physical exercise or visual perceptual learning (vPL) appear particularly promising in terms of future applicability in the clinical setting. In this survey, we will review recent literature concerning the application of these behavioral intervention strategies to the treatment of amblyopia, with a focus on possible underlying molecular and cellular mechanisms. PMID:26578911

Treatment of amblyopia in the adult: insights from a new rodent model of visual perceptual learning.

PubMed

Bonaccorsi, Joyce; Berardi, Nicoletta; Sale, Alessandro

2014-01-01

Amblyopia is the most common form of impairment of visual function affecting one eye, with a prevalence of about 1-5% of the total world population. Amblyopia usually derives from conditions of early functional imbalance between the two eyes, owing to anisometropia, strabismus, or congenital cataract, and results in a pronounced reduction of visual acuity and severe deficits in contrast sensitivity and stereopsis. It is widely accepted that, due to a lack of sufficient plasticity in the adult brain, amblyopia becomes untreatable after the closure of the critical period in the primary visual cortex. However, recent results obtained both in animal models and in clinical trials have challenged this view, unmasking a previously unsuspected potential for promoting recovery even in adulthood. In this context, non invasive procedures based on visual perceptual learning, i.e., the improvement in visual performance on a variety of simple visual tasks following practice, emerge as particularly promising to rescue discrimination abilities in adult amblyopic subjects. This review will survey recent work regarding the impact of visual perceptual learning on amblyopia, with a special focus on a new experimental model of perceptual learning in the amblyopic rat.

Treatment of amblyopia in the adult: insights from a new rodent model of visual perceptual learning

PubMed Central

Bonaccorsi, Joyce; Berardi, Nicoletta; Sale, Alessandro

2014-01-01

Amblyopia is the most common form of impairment of visual function affecting one eye, with a prevalence of about 1–5% of the total world population. Amblyopia usually derives from conditions of early functional imbalance between the two eyes, owing to anisometropia, strabismus, or congenital cataract, and results in a pronounced reduction of visual acuity and severe deficits in contrast sensitivity and stereopsis. It is widely accepted that, due to a lack of sufficient plasticity in the adult brain, amblyopia becomes untreatable after the closure of the critical period in the primary visual cortex. However, recent results obtained both in animal models and in clinical trials have challenged this view, unmasking a previously unsuspected potential for promoting recovery even in adulthood. In this context, non invasive procedures based on visual perceptual learning, i.e., the improvement in visual performance on a variety of simple visual tasks following practice, emerge as particularly promising to rescue discrimination abilities in adult amblyopic subjects. This review will survey recent work regarding the impact of visual perceptual learning on amblyopia, with a special focus on a new experimental model of perceptual learning in the amblyopic rat. PMID:25076874

Stereoscopically Observing Manipulative Actions.

PubMed

Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

2016-08-01

The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. © The Author 2016. Published by Oxford University Press.

Duane's retraction syndrome: a retrospective review from Kathmandu, Nepal.

PubMed

Shrestha, Gauri Shankar; Sharma, Ananda Kumar

2012-01-01

  The aim was to study the clinical characteristics of Duane's retraction syndrome (DRS) in Nepalese patients.   Medical records from 52 cases of DRS from May 2003 to April 2010 were retrospectively reviewed for age, gender, laterality and clinical characteristics. Forty-one case records (78.8 per cent) that had complete clinical findings were considered for further evaluation. Examination included visual acuity by Snellen chart, refraction, associated horizontal and vertical strabismus in primary gaze, upshoot and downshoot on attempted adduction, binocular vision assessed with the Worth four-dot test on adopted gaze and stereopsis examined with the Titmus stereo test.   DRS type I was the most common type observed in 73.2 per cent of cases, followed by DRS type II (14.6 per cent) and DRS type III (12.2 per cent). It was more common in female patients (58.5 per cent) than male patients (χ(2) = 4.6, df = 1, p = 0.03). DRS was more common in the left eye (68.3 per cent) than the right eye and unilaterally present in 95.1 per cent of subjects. In primary gaze, orthotropia (41.5 per cent) was more common than exotropia (34.1 per cent) and esotropia (24.4 per cent) and vertical strabismus was present in 24.4 per cent of subjects. Upshoot and downshoot on attempted adduction was seen in 14.6 and 9.8 per cent, respectively. Binocular single vision was present in 68.3 per cent of subjects by Worth four-dot test at near. Stereopsis of 3,000 seconds of arc was present in 9.8 per cent, 100 to 200 seconds of arc in 14.6 per cent and 40 to 60 seconds of arc in 43.9 per cent with the Titmus stereo test.   DRS is more common in female patients and the left eye. DRS type I is the most common type. © 2011 The Authors. Clinical and Experimental Optometry © 2011 Optometrists Association Australia.

Stereopsis and amblyopia: A mini-review

PubMed Central

Levi, Dennis M.; Knill, David C.; Bavelier, Daphne

2015-01-01

Amblyopia is a neuro-developmental disorder of the visual cortex that arises from abnormal visual experience early in life. Amblyopia is clinically important because it is a major cause of vision loss in infants and young children. Amblyopia is also of basic interest because it reflects the neural impairment that occurs when normal visual development is disrupted. Amblyopia provides an ideal model for understanding when and how brain plasticity may be harnessed for recovery of function. Over the past two decades there has been a rekindling of interest in developing more effective methods for treating amblyopia, and for extending the treatment beyond the critical period, as exemplified by new clinical trials and new basic research studies. The focus of this review is on stereopsis and its potential for recovery. Impaired stereoscopic depth perception is the most common deficit associated with amblyopia under ordinary (binocular) viewing conditions (Webber & Wood, 2005). Our review of the extant literature suggests that this impairment may have a substantial impact on visuomotor tasks, difficulties in playing sports in children and locomoting safely in older adults. Furthermore, impaired stereopsis may also limit career options for amblyopes. Finally, stereopsis is more impacted in strabismic than in anisometropic amblyopia. Our review of the various approaches to treating amblyopia (patching, perceptual learning, videogames) suggests that there are several promising new approaches to recovering stereopsis in both anisometropic and strabismic amblyopes. However, recovery of stereoacuity may require more active treatment in strabismic than in anisometropic amblyopia. Individuals with strabismic amblyopia have a very low probability of improvement with monocular training; however they fare better with dichoptic training than with monocular training, and even better with direct stereo training. PMID:25637854

Alternation frequency thresholds for stereopsis as a technique for exploring stereoscopic difficulties

PubMed Central

Rychkova, Svetlana; Ninio, Jacques

2011-01-01

When stereoscopic images are presented alternately to the two eyes, stereopsis occurs at F ≥ 1 Hz full-cycle frequencies for very simple stimuli, and F ≥ 3 Hz full-cycle frequencies for random-dot stereograms (eg Ludwig I, Pieper W, Lachnit H, 2007 “Temporal integration of monocular images separated in time: stereopsis, stereoacuity, and binocular luster” Perception & Psychophysics 69 92–102). Using twenty different stereograms presented through liquid crystal shutters, we studied the transition to stereopsis with fifteen subjects. The onset of stereopsis was observed during a stepwise increase of the alternation frequency, and its disappearance was observed during a stepwise decrease in frequency. The lowest F values (around 2.5 Hz) were observed with stimuli involving two to four simple disjoint elements (circles, arcs, rectangles). Higher F values were needed for stimuli containing slanted elements or curved surfaces (about 1 Hz increment), overlapping elements at two different depths (about 2.5 Hz increment), or camouflaged overlapping surfaces (> 7 Hz increment). A textured cylindrical surface with a horizontal axis appeared easier to interpret (5.7 Hz) than a pair of slanted segments separated in depth but forming a cross in projection (8 Hz). Training effects were minimal, and F usually increased as disparities were reduced. The hierarchy of difficulties revealed in the study may shed light on various problems that the brain needs to solve during stereoscopic interpretation. During the construction of the three-dimensional percept, the loss of information due to natural decay of the stimuli traces must be compensated by refreshes of visual input. In the discussion an attempt is made to link our results with recent advances in the comprehension of visual scene memory. PMID:23145225

AI And Early Vision - Part II

NASA Astrophysics Data System (ADS)

Julesz, Bela

1989-08-01

A quarter of a century ago I introduced two paradigms into psychology which in the intervening years have had a direct impact on the psychobiology of early vision and an indirect one on artificial intelligence (AI or machine vision). The first, the computer-generated random-dot stereogram (RDS) paradigm (Julesz, 1960) at its very inception posed a strategic question both for AI and neurophysiology. The finding that stereoscopic depth perception (stereopsis) is possible without the many enigmatic cues of monocular form recognition - as assumed previously - demonstrated that stereopsis with its basic problem of finding matches between corresponding random aggregates of dots in the left and right visual fields became ripe for modeling. Indeed, the binocular matching problem of stereopsis opened up an entire field of study, eventually leading to the computational models of David Marr (1982) and his coworkers. The fusion of RDS had an even greater impact on neurophysiologists - including Hubel and Wiesel (1962) - who realized that stereopsis must occur at an early stage, and can be studied easier than form perception. This insight recently culminated in the studies by Gian Poggio (1984) who found binocular-disparity - tuned neurons in the input stage to the visual cortex (layer IVB in V1) in the monkey that were selectively triggered by dynamic RDS. Thus the first paradigm led to a strategic insight: that with stereoscopic vision there is no camouflage, and as such was advantageous for our primate ancestors to evolve the cortical machinery of stereoscopic vision to capture camouflaged prey (insects) at a standstill. Amazingly, although stereopsis evolved relatively late in primates, it captured the very input stages of the visual cortex. (For a detailed review, see Julesz, 1986a)

An evaluation of stereoacuity (3D vision) in practising surgeons across a range of surgical specialities.

PubMed

Biddle, Mairiosa; Hamid, Sana; Ali, Nadeem

2014-02-01

Judging depth is important in surgery. Although there are several cues that permit depth perception, stereoacuity has been singled out as a possible predictor of surgical ability. However, it is not clear whether high-grade stereoacuity is necessary for a career in surgery. To help answer this, we aimed to evaluate stereoacuities in practising surgeons across a range of surgical specialities. We recorded stereoacuity values on 66 surgeons working at a London teaching hospital using three standard stereotests: Titmus, TNO and Frisby. There were 36 Trainees and 30 Consultants, covering 12 surgical specialities. Median stereoacuities (with range) for the whole group were: 40 s arc on Titmus (40-800), 30 s arc on TNO (15-480) and 20 s arc on Frisby (20-600). Four surgeons had no recordable stereoacuity on TNO, and one was also unrecordable on Titmus. Three of these four were Consultants. Depending on the test used, high-grade stereopsis was found in 74%-83% of surgeons while reduced stereopsis was found in 2%-14% of surgeons. While we found that most surgeons in current NHS practice have high-grade stereoacuity, there are also surgeons with reduced stereopsis and some with no stereopsis. The findings do not therefore support the assertion that high-grade stereopsis is a universal requirement for a career in surgery. It would be difficult to justify setting a stereoacuity criterion for entrance into a surgical training programme. Copyright © 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Stereopsis and amblyopia: A mini-review.

PubMed

Levi, Dennis M; Knill, David C; Bavelier, Daphne

2015-09-01

Amblyopia is a neuro-developmental disorder of the visual cortex that arises from abnormal visual experience early in life. Amblyopia is clinically important because it is a major cause of vision loss in infants and young children. Amblyopia is also of basic interest because it reflects the neural impairment that occurs when normal visual development is disrupted. Amblyopia provides an ideal model for understanding when and how brain plasticity may be harnessed for recovery of function. Over the past two decades there has been a rekindling of interest in developing more effective methods for treating amblyopia, and for extending the treatment beyond the critical period, as exemplified by new clinical trials and new basic research studies. The focus of this review is on stereopsis and its potential for recovery. Impaired stereoscopic depth perception is the most common deficit associated with amblyopia under ordinary (binocular) viewing conditions (Webber & Wood, 2005). Our review of the extant literature suggests that this impairment may have a substantial impact on visuomotor tasks, difficulties in playing sports in children and locomoting safely in older adults. Furthermore, impaired stereopsis may also limit career options for amblyopes. Finally, stereopsis is more impacted in strabismic than in anisometropic amblyopia. Our review of the various approaches to treating amblyopia (patching, perceptual learning, videogames) suggests that there are several promising new approaches to recovering stereopsis in both anisometropic and strabismic amblyopes. However, recovery of stereoacuity may require more active treatment in strabismic than in anisometropic amblyopia. Individuals with strabismic amblyopia have a very low probability of improvement with monocular training; however they fare better with dichoptic training than with monocular training, and even better with direct stereo training. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spatial constraints of stereopsis in video displays

NASA Technical Reports Server (NTRS)

Schor, Clifton

1989-01-01

Recent development in video technology, such as the liquid crystal displays and shutters, have made it feasible to incorporate stereoscopic depth into the 3-D representations on 2-D displays. However, depth has already been vividly portrayed in video displays without stereopsis using the classical artists' depth cues described by Helmholtz (1866) and the dynamic depth cues described in detail by Ittleson (1952). Successful static depth cues include overlap, size, linear perspective, texture gradients, and shading. Effective dynamic cues include looming (Regan and Beverly, 1979) and motion parallax (Rogers and Graham, 1982). Stereoscopic depth is superior to the monocular distance cues under certain circumstances. It is most useful at portraying depth intervals as small as 5 to 10 arc secs. For this reason it is extremely useful in user-video interactions such as telepresence. Objects can be manipulated in 3-D space, for example, while a person who controls the operations views a virtual image of the manipulated object on a remote 2-D video display. Stereopsis also provides structure and form information in camouflaged surfaces such as tree foliage. Motion parallax also reveals form; however, without other monocular cues such as overlap, motion parallax can yield an ambiguous perception. For example, a turning sphere, portrayed as solid by parallax can appear to rotate either leftward or rightward. However, only one direction of rotation is perceived when stereo-depth is included. If the scene is static, then stereopsis is the principal cue for revealing the camouflaged surface structure. Finally, dynamic stereopsis provides information about the direction of motion in depth (Regan and Beverly, 1979). Clearly there are many spatial constraints, including spatial frequency content, retinal eccentricity, exposure duration, target spacing, and disparity gradient, which - when properly adjusted - can greatly enhance stereodepth in video displays.

Binocular Vision

PubMed Central

Blake, Randolph; Wilson, Hugh

2010-01-01

This essay reviews major developments –empirical and theoretical –in the field of binocular vision during the last 25 years. We limit our survey primarily to work on human stereopsis, binocular rivalry and binocular contrast summation, with discussion where relevant of single-unit neurophysiology and human brain imaging. We identify several key controversies that have stimulated important work on these problems. In the case of stereopsis those controversies include position versus phase encoding of disparity, dependence of disparity limits on spatial scale, role of occlusion in binocular depth and surface perception, and motion in 3D. In the case of binocular rivalry, controversies include eye versus stimulus rivalry, role of “top-down” influences on rivalry dynamics, and the interaction of binocular rivalry and stereopsis. Concerning binocular contrast summation, the essay focuses on two representative models that highlight the evolving complexity in this field of study. PMID:20951722

The effects of surgical factors on postoperative astigmatism in patients enrolled in the Infant Aphakia Treatment Study (IATS).

PubMed

Wall, Palak B; Lee, Jason A; Lynn, Michael J; Lambert, Scott R; Traboulsi, Elias I

2014-10-01

To evaluate the effect of surgical factors on postoperative astigmatism in infants undergoing cataract extraction with or without intraocular lens (IOL) implantation. The Infant Aphakia Treatment Study is a multicenter clinical trial in which 114 infants with unilateral congenital cataracts were randomized to undergo cataract extraction with IOL placement or contact lens aphakic correction. Surgical videos were reviewed with regard to incision type and location, whether the incision was extended, the number of sutures placed, and technique of closure. Corneal astigmatism was measured using a handheld keratometer prior to surgery and at 1 year of age. Corneal astigmatism decreased from a mean of 1.92 D at baseline to 1.62 D at age 1 year in the contact lens group but remained almost unchanged from 2.00 D to 2.09 D in the IOL group (P = 0.023). There was no statistical difference between the amount of corneal astigmatism with regard to incision type (P = 0.214) and no increase in astigmatism with extension of the incision to facilitate IOL placement (P = 0.849) at 1 year. The number of sutures and technique of closure did not influence the amount of astigmatism at 1 year. At the age of 1 year following cataract extraction in infants, contact lens correction and the lack of IOL placement are associated with a significant decrease in postoperative corneal astigmatism compared to IOL placement. No other surgical factors considered in this study had a statistically significant effect on corneal astigmatism. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

The Effects of Surgical Factors on Postoperative Astigmatism in Patients Enrolled in the Infant Aphakia Treatment Study (IATS)

PubMed Central

Wall, Palak B.; Lee, Jason A.; Lynn, Michael; Lambert, Scott R.; Traboulsi, Elias I.

2015-01-01

Purpose To evaluate the impact of surgical factors such as incision type, number of sutures, and technique of closure on postoperative astigmatism in infants undergoing cataract extraction with or without intraocular lens implantation. Methods The IATS is a multicenter (n=12) clinical trial in which 114 infants with unilateral congenital cataracts were randomized to undergo cataract extraction with intraocular lens (IOL) placement or contact lens aphakic correction. Surgical videos were reviewed with regard to incision type and location, whether the incision was extended, the number of sutures placed, and technique of closure. Corneal astigmatism was measured using a handheld keratometer prior to surgery and at 1 year of age. Results Corneal astigmatism decreased from a mean of 1.92 D at baseline to 1.62 D at age 1 year in the CL group, but remained almost unchanged from 2.00 D to 2.09 D in the IOL group (p=0.023). There was no statistical difference between the amount of corneal astigmatism irrespective of incision type (p=0.214) and no increase in astigmatism with extension of the incision to facilitate IOL placement (p=0.849) at 1 year. The number of sutures and technique of closure did not influence the amount of astigmatism at 1 year. Conclusions At the age of one year following cataract extraction in infants, contact lens correction and the lack of IOL placement are associated with a significant decrease in postoperative corneal astigmatism compared to intraocular lens placement. No other surgical factors considered in this study had a statistically significant impact on corneal astigmatism. PMID:25266831

A retrospective study on the outcomes of cataract surgery in an Eastern Regional Health Authority hospital of Trinidad and Tobago

PubMed Central

Sonron, Ebiakpo-aboere; Bridgemohan, Petra; Sharma, Subash

2015-01-01

Background. Worldwide, cataract is a major cause of blindness. The paper aims to evaluate factors associated with borderline and poor outcomes of cataract surgery at an Eastern Regional Health Authority (ERHA) hospital in Trinidad and Tobago. Materials and Methods. A hospital-based, retrospective study was done on 401 patients who had undergone cataract surgery (unilateral and bilateral) at an ERHA Hospital between March 2009 and September 2014. Data was collected on variables concerning demographic, medical history, surgical history, ocular findings and visual acuity (VA). The outcome variable of interest was Snellen’s post-operative (presenting) VA which was transformed into a dichotomous variable with borderline and poor outcomes as one and good outcomes as the other. Data were analysed using univariate and multivariate logistic regression analyses. Results. Good outcome (presenting VA 6/18 or better) was seen in 350 (67%) eyes. The fitted model consisted of ocular co-morbidity (OR =2.133; 95% CI [1.346–3.380]), hypertension (OR = 0.520; 95% CI [0.381–0.928]), surgical procedure (OR = 1.56; 95% CI [1.004–2.425]), good preoperative VA (OR = 0.388, 95% CI [0.211–0.714]), borderline preoperative VA (OR = 0.485; 95% CI = [0.278–0.843]) and year of first visit to clinic (OR = 2.243; 95% CI [1.215–4.141]). Conclusion. There is a need for community-based outreach to increase awareness of eye health and diseases. It is recommended that the general population is encouraged to take responsibility for personal management. The facilities at the Hospital should also be enhanced. PMID:26357596

Safety, efficacy and cost-effectiveness of consecutive bilateral cataract surgery on two successive days in tribes at base hospital through community outreach program: A prospective study of Aravali Mountain, North West India

PubMed Central

Mohan, Amit; Kaur, Navjot; Bhatanagar, Vishal C

2017-01-01

Purpose: The aim of the study was to evaluate the safety and efficacy of consecutive bilateral cataract surgery (CBCS) on two successive days in a single hospital visit. Methods: Prospective study was conducted on 565 patients of various tribes of hilly area of West Rajasthan who had come to our hospital through community outreach programmed (CORP) between January 2015 and March 2016. Patients with significant bilateral cataract without any other ocular morbidity were advised bilateral manual small incision cataract surgery on two consecutive days. Intraoperative and postoperative complications were evaluated, and follow-up was done at 1 week, 1 month, and 3 months. Results: Out of 565 patients, 519 underwent both eye surgeries. Second eye surgery was deferred for a later date in 46 cases. Because of intraoperative and postoperative complications in the first eye, 31 had delayed surgeries while 15 patients refused to undergo another eye surgery either because of postoperative day 1 poor vision in the operated eye due to retinal pathologies (n = 8) or unwillingness (n = 7). The second eye surgery was performed for 519 patients, out of whom six had intra or postoperative complications. At 1 month follow-up, four patients had unilateral cystoid macular edema and three had prolonged postoperative inflammation. At 3 months, all patients were satisfied and had no complications. None of the patients had sight-threatening complications such as endophthalmitis, corneal decompensation, or vitreoretinal complications. Conclusion: CBCS may be considered safe and cost-effective for patients living in remote locations, dependent on CORP. PMID:29208839

Determinants of pediatric cataract program outcomes and follow-up in a large series in Mexico.

PubMed

Congdon, Nathan G; Ruiz, Sergio; Suzuki, Maki; Herrera, Veronica

2007-10-01

To report determinants of outcomes and follow-up in a large Mexican pediatric cataract project. Hospital Luis Sanchez Bulnes, Mexico City, Mexico. Data were collected prospectively from a pediatric cataract surgery program at the Hospital Luis Sanchez Bulnes, implemented by Helen Keller International. Preoperative data included age, sex, baseline visual acuity, type of cataract, laterality, and presence of conditions such as amblyopia. Surgical data included vitrectomy, capsulotomy, complications, and use of intraocular lenses (IOLs). Postoperative data included final visual acuity, refraction, number of follow-up visits, and program support for follow-up. Of 574 eyes of 415 children (mean age 7.1 years +/- 4.7 [SD]), IOLs were placed in 416 (87%). At least 1 follow-up was attended by 408 patients (98.3%) (mean total follow-up 3.5 +/- 1.8 months); 40% of eyes achieved a final visual acuity of 6/18 or better. Children living farther from the hospital had fewer postoperative visits (P = .04), while children receiving program support had more visits (P = .001). Factors predictive of better acuity included receiving an IOL during surgery (P = .04) and provision of postoperative spectacles (P = .001). Predictive of worse acuity were amblyopia (P = .003), postoperative complications (P = .0001), unilateral surgery (P = .0075), and female sex (P = .045). The results underscore the importance of surgical training in reducing complications, early intervention before amblyopia (observed in 40% of patients) can develop, and vigorous treatment if amblyopia is present. The positive impact of program support on follow-up is encouraging, although direct financial support may pose a problem for sustainability. More work is needed to understand reasons for worse outcomes in girls.

Exotropia in children with high hyperopia

PubMed Central

Kassem, Iris S; Rubin, Steven E; Kodsi, Sylvia R

2012-01-01

Purpose To describe the clinical characteristics, treatment, and subsequent clinical course of children with exotropia and high hyperopia. Methods The medical records of 26 patients seen between 1990 and 2009 who had an exotropia and ≥4.00 D of hyperopia were retrospectively reviewed. We analyzed the clinical characteristics, treatments and subsequent alignment outcomes. Results A total of 26 patients between the ages of 2.5 months and 9 years were included. Of these, 15 had associated medical conditions or developmental delay. Of 22 patients with measured visual acuities, 19 had amblyopia (10 unilateral, 9 bilateral). None of the patients demonstrated fine stereoacuity. Twenty-three exotropic children were treated with spectacles; 15 were fully corrected, 10 of whose exotropia improved; 8 received partial correction of their hyperopia, 3 of whose exotropia improved. Six patients who presented with large, poorly controlled exotropia and did not improve with spectacle correction required strabismus surgery. Conclusions Children with high hyperopia and exotropia are likely to have developmental delay or other systemic diseases, amblyopia, and poor stereopsis. Treatment of high hyperopia in exotropic children with their full cycloplegic refraction can result in excellent alignment. PMID:23084380

Psychophysical Studies of Visual Cortical Function

DTIC Science & Technology

1992-01-12

principle of generic image samplin& a hypothesis which provides ageometric tool to understand visual surface learning. We also have investigated the...perception of depth from unpaired points ( DaVinci stereopsis), showing that such points lead to depth andsubjective contours. In color filling in, we have...outlined and systematized a number of important phenomenon which we label under the rubric of DaVinci stereopsis. We summarize these results in a number of

Temporal integration property of stereopsis after higher-order aberration correction

PubMed Central

Kang, Jian; Dai, Yun; Zhang, Yudong

2015-01-01

Based on a binocular adaptive optics visual simulator, we investigated the effect of higher-order aberration correction on the temporal integration property of stereopsis. Stereo threshold for line stimuli, viewed in 550nm monochromatic light, was measured as a function of exposure duration, with higher-order aberrations uncorrected, binocularly corrected or monocularly corrected. Under all optical conditions, stereo threshold decreased with increasing exposure duration until a steady-state threshold was reached. The critical duration was determined by a quadratic summation model and the high goodness of fit suggested this model was reasonable. For normal subjects, the slope for stereo threshold versus exposure duration was about −0.5 on logarithmic coordinates, and the critical duration was about 200 ms. Both the slope and the critical duration were independent of the optical condition of the eye, showing no significant effect of higher-order aberration correction on the temporal integration property of stereopsis. PMID:26601010

Evolution of light scattering and redox balance in the rat lens after in vivo exposure to close-to-threshold dose ultraviolet radiation.

PubMed

Wang, Jing; Löfgren, Stefan; Dong, Xiuqin; Galichanin, Konstantin; Söderberg, Per G

2010-11-01

To investigate the evolution of cataract development and glutathione redox balance in the rat lens after in vivo close-to-threshold dose exposure to ultraviolet radiation (UVR) around 300 nm. Three groups of 10 Sprague-Dawley rats were unilaterally exposed to 8 kJ/m² UVR-300 nm for 15 min, and a fourth group of 10 rats was kept without UVR exposure as nonexposed control animals. The exposed animals were killed at 1, 3 and 7 days after exposure. Both lenses from all animals were extracted and photographed and the intensity of forward light scattering was measured quantitatively. Thereafter, the lenses were homogenized. The concentration of reduced glutathione (GSH) and oxidized glutathione (GSSG), and the activity of glutathione reductase (GR) and glutathione peroxidase (GPx), respectively, were determined spectrophotometrically. The mean paired differences between exposed and nonexposed lenses were used as primary data in the statistical analyses. All exposed lenses developed cataract. Lens light scattering increased throughout the 7 days after UVR exposure. GSH concentration and GPx rate transiently increased at 1 day after exposure and then decreased throughout follow-up, with GSH concentration having a negative balance at the end. GSSG concentration and GR activity did not change after UVR exposure. In vivo close-to-threshold UVR exposure induces a gradual increase in rat lens opacification/cataract development and time dependently alters the redox balance in the lens. © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

Comparison of topically applied flurbiprofen or bromfenac ophthalmic solution on post-operative ocular hypertension in canine patients following cataract surgery.

PubMed

Lu, Jennifer; English, Robert; Nadelstein, Brad; Weigt, Anne; Berdoulay, Andrew; Binder, Dan; Ngan, Esther

2017-03-01

To compare the prevalence and kinetics of ocular hypertension after routine cataract extraction when using a predominately COX-2 inhibitor (bromfenac) versus a predominately COX-1 inhibitor (flurbiprofen) in combination with a topical corticosteroid. Patients undergoing unilateral or bilateral cataract surgery were randomly assigned to receive flurbiprofen or bromfenac at the day of surgery and continued for 6 weeks postoperatively, along with topical neo poly dexamethasone. No systemic nonsteroidal anti-inflammatory medications were administered before or after surgery. Intraocular pressure was monitored pre and postoperatively. When an IOP of >25 mmHg was detected, therapeutic intervention was performed. Eyes in both treatment groups showed a similar IOP profile with the highest mean IOP occurring two hours postsurgery and slowly declining during the next 6 weeks. However, eyes receiving bromfenac had a higher mean IOP at 2 h post-op (22.1 mmHg) than eyes receiving flurbiprofen (18.8 mmHg) and a slower decrease in IOP in the weeks after surgery. Over the course of the study, a higher percentage of eyes receiving bromfenac had therapy discontinued over concerns of elevated IOP compared to eyes receiving flurbiprofen (bromfenac 23.1% and flurbiprofen 9.8%). On average, the risk of having elevated intraocular pressure with bromfenac is 1.04 times higher than with flurbiprofen. Elevated postoperative IOP was observed in both treatment groups; however, bromfenac-treated eyes were more likely to require intervention for elevated IOP. © 2016 American College of Veterinary Ophthalmologists.

Amblyopia treatment strategies and new drug therapies.

PubMed

Pescosolido, Nicola; Stefanucci, Alessio; Buomprisco, Giuseppe; Fazio, Stefano

2014-01-01

Amblyopia is a unilateral or bilateral reduction of visual acuity secondary to abnormal visual experience during early childhood. It is one of the most common causes of vision loss and monocular blindness and is commonly associated with strabismus, anisometropia, and visual deprivation (in particular congenital cataract and ptosis). It is clinically defined as a two-line difference of best-corrected visual acuity between the eyes. The purpose of this study was to understand the neural mechanisms of amblyopia and summarize the current therapeutic strategies. In particular, the authors focused on the concept of brain plasticity and its implication for new treatment strategies for children and adults with amblyopia. Copyright 2014, SLACK Incorporated.

Stereopsis and 3D surface perception by spiking neurons in laminar cortical circuits: a method for converting neural rate models into spiking models.

PubMed

Cao, Yongqiang; Grossberg, Stephen

2012-02-01

A laminar cortical model of stereopsis and 3D surface perception is developed and simulated. The model shows how spiking neurons that interact in hierarchically organized laminar circuits of the visual cortex can generate analog properties of 3D visual percepts. The model describes how monocular and binocular oriented filtering interact with later stages of 3D boundary formation and surface filling-in in the LGN and cortical areas V1, V2, and V4. It proposes how interactions between layers 4, 3B, and 2/3 in V1 and V2 contribute to stereopsis, and how binocular and monocular information combine to form 3D boundary and surface representations. The model suggests how surface-to-boundary feedback from V2 thin stripes to pale stripes helps to explain how computationally complementary boundary and surface formation properties lead to a single consistent percept, eliminate redundant 3D boundaries, and trigger figure-ground perception. The model also shows how false binocular boundary matches may be eliminated by Gestalt grouping properties. In particular, the disparity filter, which helps to solve the correspondence problem by eliminating false matches, is realized using inhibitory interneurons as part of the perceptual grouping process by horizontal connections in layer 2/3 of cortical area V2. The 3D sLAMINART model simulates 3D surface percepts that are consciously seen in 18 psychophysical experiments. These percepts include contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, Panum's limiting case, the Venetian blind illusion, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and perceptual closure. The model hereby illustrates a general method of unlumping rate-based models that use the membrane equations of neurophysiology into models that use spiking neurons, and which may be embodied in VLSI chips that use spiking neurons to minimize heat production. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Active Side of Stereopsis: Fixation Strategy and Adaptation to Natural Environments.

PubMed

Gibaldi, Agostino; Canessa, Andrea; Sabatini, Silvio P

2017-03-20

Depth perception in near viewing strongly relies on the interpretation of binocular retinal disparity to obtain stereopsis. Statistical regularities of retinal disparities have been claimed to greatly impact on the neural mechanisms that underlie binocular vision, both to facilitate perceptual decisions and to reduce computational load. In this paper, we designed a novel and unconventional approach in order to assess the role of fixation strategy in conditioning the statistics of retinal disparity. We integrated accurate realistic three-dimensional models of natural scenes with binocular eye movement recording, to obtain accurate ground-truth statistics of retinal disparity experienced by a subject in near viewing. Our results evidence how the organization of human binocular visual system is finely adapted to the disparity statistics characterizing actual fixations, thus revealing a novel role of the active fixation strategy over the binocular visual functionality. This suggests an ecological explanation for the intrinsic preference of stereopsis for a close central object surrounded by a far background, as an early binocular aspect of the figure-ground segregation process.

Clinical Outcomes of Intravitreal Preservative-Free Triamcinolone Preparation (Triesence®) for Cystoid Macular Oedema and Inflammation in Patients with Uveitis.

PubMed

Steeples, Laura R; Anand, Nitin; Moraji, Jiten; Jones, Nicholas P

2017-03-20

To assess the outcomes of intravitreal benzyl alcohol-free triamcinolone acetonide suspension in uveitis-related macular oedema. Single-center retrospective cohort study of 66 injections to 44 eyes of 40 patients. Uveitis diagnosis, systemic and local therapy, intraocular pressure (IOP), central retinal thickness (CRT), number of injections, time to re-injection and side-effects were noted during 6-months minimum follow-up. Sixty eight percent of eyes received a single injection. 18% required 2 injections, and 13% received ≥3 injections with mean time to second and third injections of 25.5 and 52.7 weeks, respectively. 90% of injections were unilateral. Mean CRT reduced, and by 12-weeks visual acuity improvement >0.3logMar was achieved in 46%. Cataract progression (47%) and IOP>21 mmHg (45%) were the commonest adverse events. Preservative-free triamcinolone is an additional option for uveitis-related macular oedema, particularly in unilateral cases, with favorable CRT and visual outcomes. Repeat injections may be necessary, and the period of efficacy varies between eyes.

[Amblyopia. Epidemiology, causes and risk factors].

PubMed

Elflein, H M

2016-04-01

Amblyopia is the main cause for mostly monocular, impaired vision in childhood. Treatment and prevention of amblyopia is only effective during childhood. Ophthalmological screening of children does not yet exist in Germany. The prevalence of amblyopia in Germany is 5.6%, which is higher than in reports from studies in Australia; however, the prevalence of amblyopia is not comparable in these studies due to different definitions of amblyopia and the inclusion/exclusion criteria of the study cohorts. At present it is unknown at what age ophthalmological screening should be carried out to prevent amblyopia and the appropriate frequency of screening examinations. Amblyopia is a disorder of the visual cortex that is due to suppression and deprivation of one eye leading to unilateral visual impairment. Approximately 50% of cases of amblyopia are caused by anisometropia, 25% by strabismus and in every sixth person by a combination of both. Other causes, such as unilateral congenital cataracts are relatively rare. A variety of factors, such as ocular pathologies, premature birth, familial disposition and general diseases are associated with an increased risk for amblyopia.

Extensive bilateral corneal edema 6 weeks after cataract surgery: Keratopathy due to Asclepias physocarpa: a case report.

PubMed

Matsuura, Kazuki; Hatta, Shiro; Terasaka, Yuki; Inoue, Yoshitsugu

2017-01-18

Surgeons may be unaware of the ability of plant toxins to cause corneal damage. Therefore, corneal damage following intraocular surgery due to plant toxins may be misdiagnosed as postoperative infection. A 74-year-old man presented with hyperemia and reduced visual acuity in both eyes 6 weeks after uneventful cataract surgery. We observed extensive hyperemia and corneal stromal edema with Descemet's folds in both eyes. After obtaining a detailed patient history, we diagnosed plant toxin-induced corneal edema due to Asclepias physocarpa, which can induce corneal edema by inhibiting the Na + /K + ATPase activity of the corneal endothelium. Antimicrobial and steroid eye drops and an oral steroid were prescribed accordingly. Symptons began to improve on day 3 and had almost completely resolved by day 6. At 1 month, the patient had fully recovered without any sequelae. The correct diagnosis was possible in the present case as symptoms were bilateral and the patient was able to report his potential exposure to plant toxins. However, if the symptoms had been unilateral and the patient had been unaware of these toxins, he may have undergone unnecessary surgical interventions to treat non-existent postoperative endophthalmitis.

Interocular suppression in children with deprivation amblyopia.

PubMed

Hamm, Lisa; Chen, Zidong; Li, Jinrong; Black, Joanna; Dai, Shuan; Yuan, Junpeng; Yu, Minbin; Thompson, Benjamin

2017-04-01

In patients with anisometropic or strabismic amblyopia, interocular suppression can be minimized by presenting high contrast stimulus elements to the amblyopic eye and lower contrast elements to the fellow eye. This suggests a structurally intact binocular visual system that is functionally suppressed. We investigated whether suppression can also be overcome by contrast balancing in children with deprivation amblyopia due to childhood cataracts. To quantify interocular contrast balance, contrast interference thresholds were measured using an established dichoptic global motion technique for 21 children with deprivation amblyopia, 14 with anisometropic or mixed strabismic/anisometropic amblyopia and 10 visually normal children (mean age mean=9.9years, range 5-16years). We found that interocular suppression could be overcome by contrast balancing in most children with deprivation amblyopia, at least intermittently, and all children with anisometropic or mixed anisometropic/strabismic amblyopia. However, children with deprivation amblyopia due to early unilateral or bilateral cataracts could tolerate only very low contrast levels to the stronger eye indicating strong suppression. Our results suggest that treatment options reliant on contrast balanced dichoptic presentation could be attempted in a subset of children with deprivation amblyopia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deficiency of adaptive control of the binocular coordination of saccades in strabismus.

PubMed

Bucci, M P; Kapoula, Z; Eggert, T; Garraud, L

1997-10-01

Disconjugate (different in the two eyes) oculomotor adaptation is driven by the need to maintain binocular vision. Since binocular vision is deficient in strabismus, we wondered whether oculomotor disconjugate adaptive capabilities are deficient in such subjects. We studied eight adult subjects with constant, long-standing convergent strabismus of variable angles (4-30 prism D). No subject had severe amblyopia. Binocular vision was evaluated with stereoacuity tests. Two subjects had peripheral binocular vision and gross stereopsis; two other subjects had abnormal retinal correspondence and abnormal or pseudo gross stereopsis. In the other subjects binocular vision and stereopsis were absent. To stimulate disconjugate changes of saccades, subjects viewed for 20 min an image that was magnified in one eye (aniseikonia). Subjects with residual peripheral binocular vision and even subjects with pseudo or abnormal binocular vision showed disconjugate changes of the binocular coordination of their saccades; these changes reduced the disparity resulting from the aniseikonia. In contrast, for subjects without binocular vision the changes were not correlated with the disparity induced by the aniseikonia. Rather, these changes served to improve fixation of one or the other eye individually.

The effect of mitomycin C trabeculectomy on the progression of visual field defect in normal-tension glaucoma.

PubMed

Hagiwara, Y; Yamamoto, T; Kitazawa, Y

2000-03-01

We investigated in a prospective fashion the visual prognosis and complications in normal-tension glaucoma following unilateral trabeculectomy with adjunctive mitomycin C. Trabeculectomy with adjunctive mitomycin C was carried out unilaterally in 21 cases of normal-tension glaucoma. Intraocular pressure (IOP), visual prognosis, and complications were compared between the operated eyes and the non-operated fellow eyes. The follow-up period ranged from 2 to 7 years. The IOP dropped significantly from 14.8+/-1.8 mmHg (mean +/- SD) to 9.6+/-3.9 mmHg in the operated eyes (P=0.0002, Wilcoxon signed-rank test), but did not drop in the non-operated eyes. The mean deviation (MD) was -12.69+/-6.41 dB preoperatively and -14.70+/-5.49 dB at the last clinic visit in the operated eyes, whereas in non-operated eyes it was -7.85+/-5.65 dB and -11.15+/-5.62 dB, respectively. The MD deteriorated significantly in both operated and non-operated eyes (operated eyes P=0.0239, non-operated eyes: P=0.0002; Wilcoxon signed-rank test). The MD slope was -0.37+/-0.60 dB/year and -0.71+/-0.89 dB/year for the operated and non-operated eyes, respectively (P=0.5243, Mann-Whitney U-test). Visual field deterioration was more frequently observed in the non-operated eyes by a pointwise definition of the progression (P<0.05, McNemar test). Visual acuity deteriorated in 6 of the operated eyes and in 5 of the non-operated eyes. Cataract developed in 6 (29%) of the 21 operated eyes, while among the non-operated eyes 4 (19%) developed cataract. Mitomycin C trabeculectomy is effective in delaying progression of visual field defect in normal-tension glaucoma, but complications may arise and cause some visual disturbance.

Binocular function in patients with pseudophakic monovision.

PubMed

Ito, Misae; Shimizu, Kimiya; Niida, Takahiro; Amano, Rie; Ishikawa, Hitoshi

2014-08-01

To evaluate the relationship between ocular deviation and stereopsis and fusion in patients who had pseudophakic monovision surgery. Department of Ophthalmology, Kitasato University Hospital, Kanagawa, Japan. Retrospective comparative case series. Patients had surgical monovision correction with monofocal intraocular lens placement followed by routine postoperative examinations. The alternate prism cover test was used to measure motor alignment. Sensory tests for binocularity included sensory fusion determinations using the Worth 4-dot test, near stereopsis test, and fusion amplitude measured with a prism bar. Patients with monovision were categorized as having small-angle exophoria (≤10.0 prism diopters [Δ]) or moderate-angle exophoria (>10.0 Δ). This study comprised 60 patients with a mean age of 70.2 years ± 7.7 (SD). The difference in the mean stereopsis values between patients with small-angle exophoria and patients with moderate-angle exophoria was statistically significant (P<.001). In the moderate-angle exophoria group, 10 patients (62.5%) developed intermittent exotropia after surgery; however, no serious ocular deviation problems were observed. The fusion amplitudes in patients with pseudophakic monovision were approximately similar to normal values. Patients with moderate-angle exophoria were more likely to fail the Worth 4-dot test than those with small-angle exophoria. In patients with pseudophakic monovision having a near exophoria angle of more than 10.0 Δ, the possibility of changes in ocular deviation and stereopsis after surgery is a concern. Moreover, the application of monovision in patients with a previous moderate-angle exophoria should be carefully considered. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Comparison of Objective and Subjective Changes Induced by Multiple-Pinhole Glasses and Single-Pinhole Glasses

PubMed Central

2017-01-01

Multiple-pinhole (MPH) glasses are currently sold in many countries with unproven advertisements; however, their objective and subjective effects have not been investigated. Therefore, to investigate the effects of MPH glasses excluding the single-pinhole (SPH) effect, we compared the visual functional changes, reading speed, and ocular discomfort after reading caused by MPH and SPH glasses. Healthy 36 participants with a mean age of 33.1 years underwent examinations of pupil size, visual acuity (VA), depth of focus (DOF), and near point accommodation (NPA); tests for visual field (VF), contrast sensitivity (CS), stereopsis, and reading speed; and a survey of ocular discomfort after reading. Both types of pinhole glasses enlarged pupil diameter and improved VA, DOF, and NPA. However, CS, stereopsis, and VF parameters deteriorated. In comparison with SPH glasses, MPH glasses induced smaller pupil dilation (5.3 and 5.9 mm, P < 0.001) and showed better VF parameters with preserved peripheral VF. However, no significant difference was observed for VA, DOF, NPA, stereopsis, and CS. Reading speed using pinhole glasses was significantly slower than baseline; SPH glasses showed the slowest reading speed. Both types of glasses caused significant ocular discomfort after reading compared with baseline, and symptoms were worst with MPH glasses. In conclusion, both types of pinhole glasses had positive effects due to the pinhole effect; however, they had negative effects on VF, CS, stereopsis, reading speed, and ocular discomfort. In spite of the increased luminance and preserved peripheral VF with MPHs, these glasses caused more severe ocular discomfort than SPH glasses. This clinical trial was registered at www.ClinicalTrials.gov (Identifier: NCT02572544). PMID:28378561

Perceptual Learning in Children With Infantile Nystagmus: Effects on Visual Performance.

PubMed

Huurneman, Bianca; Boonstra, F Nienke; Goossens, Jeroen

2016-08-01

To evaluate whether computerized training with a crowded or uncrowded letter-discrimination task reduces visual impairment (VI) in 6- to 11-year-old children with infantile nystagmus (IN) who suffer from increased foveal crowding, reduced visual acuity, and reduced stereopsis. Thirty-six children with IN were included. Eighteen had idiopathic IN and 18 had oculocutaneous albinism. These children were divided in two training groups matched on age and diagnosis: a crowded training group (n = 18) and an uncrowded training group (n = 18). Training occurred two times per week during 5 weeks (3500 trials per training). Eleven age-matched children with normal vision were included to assess baseline differences in task performance and test-retest learning. Main outcome measures were task-specific performance, distance and near visual acuity (DVA and NVA), intensity and extent of (foveal) crowding at 5 m and 40 cm, and stereopsis. Training resulted in task-specific improvements. Both training groups also showed uncrowded and crowded DVA improvements (0.10 ± 0.02 and 0.11 ± 0.02 logMAR) and improved stereopsis (670 ± 249″). Crowded NVA improved only in the crowded training group (0.15 ± 0.02 logMAR), which was also the only group showing a reduction in near crowding intensity (0.08 ± 0.03 logMAR). Effects were not due to test-retest learning. Perceptual learning with or without distractors reduces the extent of crowding and improves visual acuity in children with IN. Training with distractors improves near vision more than training with single optotypes. Perceptual learning also transfers to DVA and NVA under uncrowded and crowded conditions and even stereopsis. Learning curves indicated that improvements may be larger after longer training.

Prevalence and risk factors for refractive errors in the Singapore Malay Eye Survey.

PubMed

Saw, Seang-Mei; Chan, Yiong-Huak; Wong, Wan-Ling; Shankar, Anoop; Sandar, Mya; Aung, Tin; Tan, Donald T H; Mitchell, Paul; Wong, Tien Yin

2008-10-01

To describe the prevalence and risk factors for myopia and other refractive errors in an urban Malay population in Singapore. Population-based, cross-sectional study. Persons of Malay ethnicity, between 40 and 80 years of age, living in Singapore. Refractive error was determined by subjective refraction and if unavailable by autorefraction. Data were analyzed for 2974 adults without previous cataract surgery and who had right eye refraction data. Risk factor data, such as education levels and near work activity, were obtained from a face-to-face interview. Myopia, defined as spherical equivalent (SE) refraction less than -0.5 diopters (D), astigmatism as cylinder less than -0.5 D, hyperopia as SE greater than 0.5 D, and anisometropia as the difference in SE greater than 1.0 D. The prevalence of myopia in the right eye was 30.7% (9.4% unilateral myopia and 21.3% bilateral myopia), the prevalence of astigmatism in the right eye was 33.3% (95% confidence interval [CI, 33.0-33.5), the prevalence of hyperopia in the right eye was 27.4% (95% CI, 24.7-27.6), and the prevalence of anisometropia was 9.9% (95% CI, 9.7-10.0). There was a U-shaped relationship between increasing age and the prevalence of myopia, which was partially explained by the age-related increase in the prevalence of cataract. In a multiple logistic regression model, female sex, age, higher educational level, and cataract were associated with myopia. Adults with myopia were more likely to have astigmatism (P<0.001) in multivariate analyses. A quarter of older adult Malay people in Singapore had myopia. Compared with previous reports of similarly aged Singapore Chinese adults, the prevalence of myopia, astigmatism, and anisometropia was lower, whereas the prevalence of hyperopia was similar.

Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

PubMed Central

Vorstenbosch, Marc; Kooloos, Jan

2017-01-01

A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F(1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items. PMID:28656109

Mechanisms of recovery of visual function in adult amblyopia through a tailored action video game.

PubMed

Vedamurthy, Indu; Nahum, Mor; Bavelier, Daphne; Levi, Dennis M

2015-02-26

Amblyopia is a deficit in vision that arises from abnormal visual experience early in life. It was long thought to develop into a permanent deficit, unless properly treated before the end of the sensitive period for visual recovery. However, a number of studies now suggest that adults with long-standing amblyopia may at least partially recover visual acuity and stereopsis following perceptual training. Eliminating or reducing interocular suppression has been hypothesized to be at the root of these changes. Here we show that playing a novel dichoptic video game indeed results in reduced suppression, improved visual acuity and, in some cases, improved stereopsis. Our relatively large cohort of adults with amblyopia, allowed us, for the first time, to assess the link between visual function recovery and reduction in suppression. Surprisingly, no significant correlation was found between decreased suppression and improved visual function. This finding challenges the prevailing view and suggests that while dichoptic training improves visual acuity and stereopsis in adult amblyopia, reduced suppression is unlikely to be at the root of visual recovery. These results are discussed in the context of their implication on recovery of amblyopia in adults.

Stereopsis cueing effects on hover-in-turbulence performance in a simulated rotorcraft

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Williams, Steven P.

1990-01-01

The efficacy of stereopsis cueing in pictorial displays was assessed in a real-time piloted simulation experiment of a rotorcraft precision hover-in-turbulence task. Seven pilots endeavored to maintain a hover by visually aligning a set of inner and outer wickets (major elements of a real-world pictorial display, thus attaining the desired hover position, in a full factorial experimental design. The display conditions examined included the presence or absence of a velocity display element (a velocity head-up display) as well as the stereopsis cueing conditions, which included non-stereo (binoptic or monoscopic - no depth cues other than those provided by a perspective, real-world display), stereo 3-D, and hyper stereo (telestereoscopic). Subjective and objective results indicated that the depth cues provided by the stereo displays enhanced the situational awareness of the pilot and enabled improved hover performance to be achieved. The velocity display element also improved the hover performance, with the best hover performance being achieved with the combined use of stereo and the velocity display element. Pilot control input data revealed that less control action was required to attain the improved hover performance with the stereo displays.

Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning.

PubMed

Luursema, Jan-Maarten; Vorstenbosch, Marc; Kooloos, Jan

2017-01-01

A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F (1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

Stereoscopically Observing Manipulative Actions

PubMed Central

Ferri, S.; Pauwels, K.; Rizzolatti, G.; Orban, G. A.

2016-01-01

The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors “stimulus type” (action, static control, and dynamic control), “stereopsis” (present, absent) and “viewpoint” (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. PMID:27252350

Color constrains depth in da Vinci stereopsis for camouflage but not occlusion.

PubMed

Wardle, Susan G; Gillam, Barbara J

2013-12-01

Monocular regions that occur with binocular viewing of natural scenes can produce a strong perception of depth--"da Vinci stereopsis." They occur either when part of the background is occluded in one eye, or when a nearer object is camouflaged against a background surface in one eye's view. There has been some controversy over whether da Vinci depth is constrained by geometric or ecological factors. Here we show that the color of the monocular region constrains the depth perceived from camouflage, but not occlusion, as predicted by ecological considerations. Quantitative depth was found in both cases, but for camouflage only when the color of the monocular region matched the binocular background. Unlike previous reports, depth failed even when nonmatching colors satisfied conditions for perceptual transparency. We show that placing a colored line at the boundary between the binocular and monocular regions is sufficient to eliminate depth from camouflage. When both the background and the monocular region contained vertical contours that could be fused, some observers appeared to use fusion, and others da Vinci constraints, supporting the existence of a separate da Vinci mechanism. The results show that da Vinci stereopsis incorporates color constraints and is more complex than previously assumed.

Mechanisms of recovery of visual function in adult amblyopia through a tailored action video game

PubMed Central

Vedamurthy, Indu; Nahum, Mor; Bavelier, Daphne; Levi, Dennis M.

2015-01-01

Amblyopia is a deficit in vision that arises from abnormal visual experience early in life. It was long thought to develop into a permanent deficit, unless properly treated before the end of the sensitive period for visual recovery. However, a number of studies now suggest that adults with long-standing amblyopia may at least partially recover visual acuity and stereopsis following perceptual training. Eliminating or reducing interocular suppression has been hypothesized to be at the root of these changes. Here we show that playing a novel dichoptic video game indeed results in reduced suppression, improved visual acuity and, in some cases, improved stereopsis. Our relatively large cohort of adults with amblyopia, allowed us, for the first time, to assess the link between visual function recovery and reduction in suppression. Surprisingly, no significant correlation was found between decreased suppression and improved visual function. This finding challenges the prevailing view and suggests that while dichoptic training improves visual acuity and stereopsis in adult amblyopia, reduced suppression is unlikely to be at the root of visual recovery. These results are discussed in the context of their implication on recovery of amblyopia in adults. PMID:25719537

Effect of microgravity on several visual functions during STS shuttle missions

NASA Technical Reports Server (NTRS)

Oneal, Melvin R.; Task, H. Lee; Genco, Louis V.

1992-01-01

Changes in the acuity of astronaut vision during flight are discussed. Parameters such as critical flicker vision, stereopsis to 10 seconds of arc, visual acuity in small steps to 20/7.7, cyclophoria, lateral and vertical phoria and retinal rivalry were tested using a visual function tester. Twenty-three Space Transportation System (STS) astronauts participated in the experiments. Their vision was assessed twice before launch and after landing, and three to four times while on-orbit and landing. No significant differences during space flight were observed for any of the visual parameters tested. In some cases, slight changes in acuity and stereopsis were observed with a subsequent return to normal vision after flight.

Special tinted contact lens on colour-defects.

PubMed

Mutilab, H A; Sharanjeet-Kaur; Keu, L K; Choo, P F

2012-01-01

The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses. A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red). The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without. The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.

Clinical Spectrum of HLA-B27-associated Ocular Inflammation.

PubMed

Pathanapitoon, Kessara; Dodds, Emilio M; Cunningham, Emmett T; Rothova, Aniki

2017-08-01

Human leukocyte antigen (HLA)-B27-associated anterior uveitis (AU) is the most commonly diagnosed form of AU and represents the largest entity of non-infectious uveitis around the world. The most typical ocular manifestation associated with HLA-B27 consists of unilateral AU of acute onset. The HLA-B27-associated acute AU represents a distinct clinical entity occurring typically in young adults between the ages of 20 and 40 years. HLA-B27-associated acute AU is typically unilateral and lasts usually several weeks and diminishes within 3 months in the majority of patients. The anterior chamber shows typically severe cellular reaction and flare, as well as a fibrinous exudate. Frequently, posterior synechiae are formed and occasionally hypopyon is present. The pattern of the disease is recurrent with a full remission between the attacks. Intraocular pressure during active periods is typically low due to inflammation of ciliary body and decreased aqueous production. Less typical presentations are also recognized and include the development of chronic inflammation, posterior segment involvement, episcleritis, and scleritis. An isolated retinal vasculitis in HLA-B27-positive patients may develop, mostly in those with inflammatory bowel disease. Chronic AU, which may be either unilateral or bilateral affects up to 20% of patients. Ocular complications of HLA-B27-associated AU are diverse and include commonly posterior synechiae, cataract, glaucoma and/or hypotony. The visual outcome and complications of HLA-B27-associated AAU are frequently being compared with HLA B27-negative patients with AU and show that the prognosis of HLA-B27-associated uveitis is rather favorable, as <2% developed legal blindness and <5% visual impairment. A novel algorithm called the "Dublin Uveitis Evaluation Tool (DUET)" has been proposed to guide ophthalmologists to refer appropriate HLA-B27-positive patients with uveitis to rheumatologists.

Familial trends in a population with macular holes.

PubMed

Kay, Christine Nichols; Pavan, Peter Reed; Small, Laurie Buccina; Zhang, Tao; Zamba, Gideon K D; Cohen, Steven Myles

2012-04-01

To determine if patients with macular hole report an increased family history of macular hole compared with control patients and compare the report of family history between patients with unilateral and bilateral macular holes. This was a multicenter case-control study. Charts of patients coded with diagnosis of macular hole were reviewed, and the diagnosis of idiopathic full-thickness macular hole was ascertained in 166 patients. The control group comprised 136 patients without macular hole or trauma who presented with senile cataract. Family history was obtained from all patients through a telephone interview. Six of 166 (3.6%) macular hole patients surveyed reported a history of macular hole in a primary relative compared with none of 136 (0.0%) control patients (odds ratio is infinity, with 95% confidence interval 1.295 to infinity); however, this finding may be explained by confounders such as age and number of family members. Two of the 142 (1.4%) patients with unilateral holes versus 4 of the 24 (16.7%) patients with bilateral holes reported a family history (odds ratio is 0.0714, with 95% confidence interval 0.0063 to 0.5537), and this finding remains significant when logistic regression is performed to evaluate variables of age and number of family members as potential confounders. There is an increased report of familial occurrence of macular hole in patients with macular holes compared with control patients; however, logistic regression relates this finding to variables of age and number of family members. Patients with bilateral macular holes are more likely to report a family history of macular hole than patients with unilateral macular holes, and this finding remains significant in the presence of age and number of family members. These findings may suggest a familial component to macular hole.

Evaluating motion parallax and stereopsis as depth cues for autostereoscopic displays

NASA Astrophysics Data System (ADS)

Braun, Marius; Leiner, Ulrich; Ruschin, Detlef

2011-03-01

The perception of space in the real world is based on multifaceted depth cues, most of them monocular, some binocular. Developing 3D-displays raises the question, which of these depth cues are predominant and should be simulated by computational means in such a panel. Beyond the cues based on image content, such as shadows or patterns, Stereopsis and depth from motion parallax are the most significant mechanisms supporting observers with depth information. We set up a carefully designed test situation, widely excluding undesired other distance hints. Thereafter we conducted a user test to find out, which of these two depth cues is more relevant and whether a combination of both would increase accuracy in a depth estimation task. The trials were conducting utilizing our autostereoscopic "Free2C"-displays, which are capable to detect the user eye position and steer the image lobes dynamically into that direction. At the same time, eye position was used to update the virtual camera's location and thereby offering motion parallax to the observer. As far as we know, this was the first time that such a test has been conducted using an autosteresocopic display without any assistive technologies. Our results showed, in accordance with prior experiments, that both cues are effective, however Stereopsis is by order of magnitude more relevant. Combining both cues improved the precision of distance estimation by another 30-40%.

Orthoptic Changes following Photorefractive Keratectomy

PubMed Central

Rajavi, Zhale; Nassiri, Nader; Azizzadeh, Monir; Ramezani, Alireza; yaseri, Mehdi

2011-01-01

Purpose To report orthoptic changes after photorefractive keratectomy (PRK). Methods This interventional case series included 297 eyes of 150 patients scheduled for PRK. Complete ophthalmologic evaluations focusing on orthoptic examinations were performed before and 3 months after PRK. Results Before PRK, 2 (1.3%) patients had esotropia which remained unchanged; 3 (2%) patients had far exotropia which improved after the procedure. Of 12 cases (8%) with initial exotropia at near, 3 (2%) cases became orthophoric, however 6 patients (4%) developed new near exotropia. A significant reduction in convergence and divergence amplitudes (P < 0.001) and a significant increase in near point of convergence (NPC) (P < 0.006) were noticed after PRK. A reduction ≥ 10 PD in convergence amplitude and ≥ 5 PD in divergence amplitude occurred in 10 and 5 patients, respectively. Four patients had initial NPC > 10 cm which remained unchanged after surgery. Out of 9 (6%) patients with baseline stereopsis > 60 seconds of arc, 2 (1.33%) showed an improvement in stereopsis following PRK. No patient developed diplopia postoperatively. Conclusion Preexisting strabismus may improve or remain unchanged after PRK, and new deviations can develop following the procedure. A decrease in fusional amplitudes, an increase in NPC, and an improvement in stereopsis may also occur after PRK. Preoperative evaluation of orthoptic status for detection of baseline abnormalities and identification of susceptible patients seem advisable. PMID:22454717

Early vision and focal attention

NASA Astrophysics Data System (ADS)

Julesz, Bela

1991-07-01

At the thirty-year anniversary of the introduction of the technique of computer-generated random-dot stereograms and random-dot cinematograms into psychology, the impact of the technique on brain research and on the study of artificial intelligence is reviewed. The main finding-that stereoscopic depth perception (stereopsis), motion perception, and preattentive texture discrimination are basically bottom-up processes, which occur without the help of the top-down processes of cognition and semantic memory-greatly simplifies the study of these processes of early vision and permits the linking of human perception with monkey neurophysiology. Particularly interesting are the unexpected findings that stereopsis (assumed to be local) is a global process, while texture discrimination (assumed to be a global process, governed by statistics) is local, based on some conspicuous local features (textons). It is shown that the top-down process of "shape (depth) from shading" does not affect stereopsis, and some of the models of machine vision are evaluated. The asymmetry effect of human texture discrimination is discussed, together with recent nonlinear spatial filter models and a novel extension of the texton theory that can cope with the asymmetry problem. This didactic review attempts to introduce the physicist to the field of psychobiology and its problems-including metascientific problems of brain research, problems of scientific creativity, the state of artificial intelligence research (including connectionist neural networks) aimed at modeling brain activity, and the fundamental role of focal attention in mental events.

Topical anesthesia with or without propofol sedation versus retrobulbar/peribulbar anesthesia for cataract extraction: prospective randomized trial.

PubMed

Kallio, H; Uusitalo, R J; Maunuksela, E L

2001-09-01

To evaluate the feasibility of intravenous sedation in addition to topical anesthesia during cataract extraction. Helsinki University Eye Hospital, Helsinki, Finland. Three hundred seventeen eyes of 291 consecutive patients having cataract surgery were prospectively randomized to receive topical (oxybuprocaine 0.4%, n = 96), combined (topical anesthesia and propofol sedation, n = 107), or retrobulbar/peribulbar (prilocaine 1.5%, n = 114) anesthesia. The intraoperative conditions were judged by the surgeon. A numerical scale (0 to 10) was used to assess the degree of pain during surgery. Outcome measures were the number of complications and adverse events registered perioperatively and 1 week postoperatively as well as Snellen visual acuity. The success of posterior chamber intraocular lens (IOL) implantation through a self-sealing clear corneal incision was 97.9%, 96.3%, and 98.2% in the topical, combined, and retrobulbar/peribulbar groups, respectively. There was no difference among the groups in pain during surgery, frequency of complications, or outcome measures. One week postoperatively, visual acuity was 20/40 or better in 81.7%, 78.5%, and 77.5% of eyes in the topical, combined, and retrobulbar/peribulbar groups, respectively. The surgeon reported significantly fewer difficulties in the retrobulbar/peribulbar group (9.8%) than in the topical (26.0%) (P =.004) or combined (21.0%) (P =.036) groups. Additional sedative/analgesic medication given intraoperatively was required significantly more often in the topical (15.6%) than in the retrobulbar/peribulbar group (2.6%) (P =.002). Patients with bilateral surgery preferred combined anesthesia over retrobulbar/peribulbar anesthesia; however, there was no significant difference in patient acceptance among groups in patients having unilateral surgery. Intravenous propofol sedation added to topical anesthesia did not improve the operative conditions or surgical outcome. Retrobulbar/peribulbar anesthesia ensured the best surgical conditions. Patients in all anesthesia groups reported high satisfaction. However, patients having bilateral surgery seemed to prefer combined anesthesia over retrobulbar/peribulbar anesthesia.

A Bayesian model of stereopsis depth and motion direction discrimination.

PubMed

Read, J C A

2002-02-01

The extraction of stereoscopic depth from retinal disparity, and motion direction from two-frame kinematograms, requires the solution of a correspondence problem. In previous psychophysical work [Read and Eagle (2000) Vision Res 40: 3345-3358], we compared the performance of the human stereopsis and motion systems with correlated and anti-correlated stimuli. We found that, although the two systems performed similarly for narrow-band stimuli, broadband anti-correlated kinematograms produced a strong perception of reversed motion, whereas the stereograms appeared merely rivalrous. I now model these psychophysical data with a computational model of the correspondence problem based on the known properties of visual cortical cells. Noisy retinal images are filtered through a set of Fourier channels tuned to different spatial frequencies and orientations. Within each channel, a Bayesian analysis incorporating a prior preference for small disparities is used to assess the probability of each possible match. Finally, information from the different channels is combined to arrive at a judgement of stimulus disparity. Each model system--stereopsis and motion--has two free parameters: the amount of noise they are subject to, and the strength of their preference for small disparities. By adjusting these parameters independently for each system, qualitative matches are produced to psychophysical data, for both correlated and anti-correlated stimuli, across a range of spatial frequency and orientation bandwidths. The motion model is found to require much higher noise levels and a weaker preference for small disparities. This makes the motion model more tolerant of poor-quality reverse-direction false matches encountered with anti-correlated stimuli, matching the strong perception of reversed motion that humans experience with these stimuli. In contrast, the lower noise level and tighter prior preference used with the stereopsis model means that it performs close to chance with anti-correlated stimuli, in accordance with human psychophysics. Thus, the key features of the experimental data can be reproduced assuming that the motion system experiences more effective noise than the stereoscopy system and imposes a less stringent preference for small disparities.

Characterization and prevalence of cataracts in Labrador Retrievers in The Netherlands.

PubMed

Kraijer-Huver, Ingrid M G; Gubbels, Ed J; Scholten, Janneke; Djajadiningrat-Laanen, Sylvia C; Boevé, Michael H; Stades, Frans C

2008-10-01

To assess the prevalence and distribution of types of cataract, investigate the effects of selective breeding on cataract development, and identify the relationship between posterior polar cataract and other types of cortical cataracts in Labrador Retrievers in The Netherlands. 9,017 Labrador Retrievers. Records of 18,283 ophthalmic examinations performed by veterinary ophthalmologists from 1977 through 2005 were reviewed. There were 522 dogs affected by hereditary cataracts in 1 or both eyes without progressive retinal atrophy (PRA) and 166 PRA-affected dogs with cataracts. These cataracts were divided into 3 groups: posterior polar (triangular) cataract, extensive immature and mature cataract, and a miscellaneous group. Dogs with PRA were analyzed separately. From 1980 through 2000, the prevalence of hereditary cataracts was stable at 8%. The prevalence of cataracts in offspring of cataract-affected dogs was significantly increased, compared with the prevalence in offspring of nonaffected dogs. The distribution of types of cataract was significantly different between dogs with primary cataracts and PRA-affected dogs. Dogs with posterior polar (triangular) cataracts produced affected offspring with the same distribution of types of cataracts as the entire population of primary cataract-affected dogs. Cataract development in the Labrador Retriever population in The Netherlands appears to be a predominantly genetic disorder. Posterior polar (triangular) cataracts appear to be related to other types of hereditary cataract. Although there is no conclusive evidence, it seems valid to continue exclusion of all Labrador Retrievers affected by any type of primary cataract from breeding.

Photochemical effects in the lens from near infrared radiation?

NASA Astrophysics Data System (ADS)

Söderberg, Per G.; Al-Saqry, Riyadh; Schulmeister, Karl; Gallichanin, Konstantin; Kronschläger, Martin; Yu, Zhaohua

2009-02-01

Conclusion: The current data are consistent with a potential photochemical effect of in vivo exposure of the crystalline lens to near infrared radiation since the onset of cataract after in just above threshold dose was at least 18 hrs delayed after the exposure. Materials and methods: The eyes of 6 weeks old Sprague-Dawley rats were exposed unilaterally in vivo to 1090 nm, 6.2 W quasi-top hat spatial distribution with a 3 mm spot on the anterior lens surface within the dilated pupil. First, four exposure time groups of rats were exposed to increasing exposure times. At 24 hrs after exposure, the difference of light scattering between the lenses from the same animal was measured. Then, based on the first experiment, four post-exposure time groups were exposed unilaterally in vivo to 8 s of 1090 nm, 6.2 W quasi-top hat spatial distribution with a 3 mm spot on the anterior lens surface within the dilated pupil. After, the intended post-exposure time, the difference of light scattering between the lenses from the same animal was measured. Results: A 3 mm spot of 6.2 W induces light scattering in the lens with exposures of at least 8 s. Further, after 8 s of 6.2 W within a 3 mm spot on the lens surface, the light scattering increase in the lens was delayed at least 18 hrs after the exposure.

Effectiveness of the 3D Monitor System for Medical Education During Neurosurgical Operation.

PubMed

Wanibuchi, Masahiko; Komatsu, Katsuya; Akiyama, Yukinori; Mikami, Takeshi; Mikuni, Nobuhiro

2018-01-01

Three-dimensional (3D) graphics are used in the medical field, especially during surgery. Although 3D monitoring is useful for medical education, its effectiveness needs to be objectively evaluated. The aim of this study was to investigate the efficacy of 3D monitoring in the surgical education of medical students. A questionnaire on high-definition 3D monitoring was given to fifth-year medical students in a 6-year program. Sixty-four students wore polarized glasses and observed a microsurgical operation through a 3D monitor. The questionnaire contained questions on stereopsis, neurosurgical interest, visual impact, comprehension of surgical anatomy and procedures, optical sharpness, active learning enhancement, and eye exhaustion. These parameters were evaluated on a 5-point scale that spanned negative and positive scores. The average score of each parameter ranged from 3.13 to 3.78, except for eye exhaustion, which was 0.88. The items for which the students reported positive perceptions (scores of 4 or 5) were stereopsis (67.2% of students), neurosurgical interest (62.5%), visual impact and optical sharpness (60.9% for both), active learning enhancement (57.8%), and comprehension of surgical anatomy (50.0%) and procedures (42.2%). By contrast, only eye exhaustion was evaluated negatively (26.6%). The use of 3D monitoring systems in medical education offers the advantage of stereopsis and contributes to surgical training. However, improvements are required to decrease eye exhaustion. Copyright © 2017 Elsevier Inc. All rights reserved.

Oscillopsia in "inverse latent" infantile nystagmus syndrome.

PubMed

Abel, Larry A; Malesic, Linda A

2007-11-01

A possibly unique individual with infantile nystagmus syndrome presented with incessant oscillopsia but good stereopsis when viewing binocularly; her nystagmus was greatly reduced with left eye occlusion. We have attempted to explain this and to identify an intervention that preserves binocular vision while maximizing perceptual stability. Eye movements were recorded and analyzed for duration of foveation (% time when the target was on or near the fovea and the eye was moving at < or = 4 degrees /sec) under different viewing conditions. Changes in foveation were compared with the patient's reports of her perceptual stability. In her right gaze null with her right eye fixating, foveation was 52.9%. This fell to 32.3% for the same eye in primary position and to 0.8% when viewing binocularly in primary position. When viewing binocularly oscillopsia was incessant; when viewing with her right eye vision was stable except in left gaze. Prism correction of her phoria greatly reduced her oscillopsia when viewing binocularly while preserving stereopsis; foveation went up to 33.7%. The patient's ability to maintain good foveation only when viewing with her right eye forces her to choose between stereopsis and stable vision. This may result from the rare combination of (1) requiring good foveation for oscillopsia suppression and (2) nystagmus deteriorating under the stress of maintaining binocularity. There may be many other infantile nystagmus syndrome patients who do not develop oscillopsia but may suffer sufficient asthenopia from a phoria to exacerbate their nystagmus.

Does partial occlusion promote normal binocular function?

PubMed

Li, Jingrong; Thompson, Benjamin; Ding, Zhaofeng; Chan, Lily Y L; Chen, Xiang; Yu, Minbin; Deng, Daming; Hess, Robert F

2012-10-03

There is growing evidence that abnormal binocular interactions play a key role in the amblyopia syndrome and represent a viable target for treatment interventions. In this context the use of partial occlusion using optical devices such as Bangerter filters as an alternative to complete occlusion is of particular interest. The aims of this study were to understand why Bangerter filters do not result in improved binocular outcomes compared to complete occlusion, and to compare the effects of Bangerter filters, optical blur and neutral density (ND) filters on normal binocular function. The effects of four strengths of Bangerter filters (0.8, 0.6, 0.4, 0.2) on letter and vernier acuity, contrast sensitivity, stereoacuity, and interocular suppression were measured in 21 observers with normal vision. In a subset of 14 observers, the partial occlusion effects of Bangerter filters, ND filters and plus lenses on stereopsis and interocular suppression were compared. Bangerter filters did not have graded effect on vision and induced significant disruption to binocular function. This disruption was greater than that of monocular defocus but weaker than that of ND filters. The effect of the Bangerter filters on stereopsis was more pronounced than their effect on monocular acuity, and the induced monocular acuity deficits did not predict the induced deficits in stereopsis. Bangerter filters appear to be particularly disruptive to binocular function. Other interventions, such as optical defocus and those employing computer generated dichoptic stimulus presentation, may be more appropriate than partial occlusion for targeting binocular function during amblyopia treatment.

Test--retest variability of Randot stereoacuity measures gathered in an unselected sample of UK primary school children.

PubMed

Adler, Paul; Scally, Andrew J; Barrett, Brendan T

2012-05-01

To determine the test-retest reliability of the Randot stereoacuity test when used as part of vision screening in schools. Randot stereoacuity (graded-circles) and logMAR visual acuity measures were gathered in an unselected sample of 139 children (aged 4-12, mean 8.1±2.1 years) in two schools. Randot testing was repeated on two occasions (average interval between successive tests 8 days, range: 1-21 days). Three Randot scores were obtained in 97.8% of children. Randot stereoacuity improved by an average of one plate (ie, one test level) on repeat testing but was little changed when tested on the third occasion. Within-subject variability was up to three test levels on repeat testing. When stereoacuity was categorised as 'fine', 'intermediate' or 'coarse', the greatest variability was found among younger children who exhibited 'intermediate' or 'coarse'/nil stereopsis on initial testing. Whereas 90.8% of children with 'fine' stereopsis (≤50 arc-seconds) on the first test exhibited 'fine' stereopsis on both subsequent tests, only ∼16% of children with 'intermediate' (>50 but ≤140 arc-seconds) or 'coarse'/nil (≥200 arc-seconds) stereoacuity on initial testing exhibited stable test results on repeat testing. Children exhibiting abnormal stereoacuity on initial testing are very likely to exhibit a normal result when retested. The value of a single, abnormal Randot graded-circles stereoacuity measure from school screening is therefore questionable.

Stereopsis and aging.

PubMed

Norman, J Farley; Norman, Hideko F; Craft, Amy E; Walton, Crystal L; Bartholomew, Ashley N; Burton, Cory L; Wiesemann, Elizabeth Y; Crabtree, Charles E

2008-10-01

Three experiments investigated whether and to what extent increases in age affect the functionality of stereopsis. The observers' ages ranged from 18 to 83 years. The overall goal was to challenge the older stereoscopic visual system by utilizing high magnitudes of binocular disparity, ambiguous binocular disparity [cf., Julesz, B., & Chang, J. (1976). Interaction between pools of binocular disparity detectors tuned to different disparities. Biological Cybernetics, 22, 107-119], and by making binocular matching more difficult. In particular, Experiment 1 evaluated observers' abilities to discriminate ordinal depth differences away from the horopter using standing disparities of 6.5-46 min arc. Experiment 2 assessed observers' abilities to discriminate stereoscopic shape using line-element stereograms. The direction (crossed vs. uncrossed) and magnitude of the binocular disparity (13.7 and 51.5 min arc) were manipulated. Binocular matching was made more difficult by varying the orientations of corresponding line elements across the two eyes' views. The purpose of Experiment 3 was to determine whether the aging stereoscopic system can resolve ambiguous binocular disparities in a manner similar to that of younger observers. The results of all experiments demonstrated that older observers' stereoscopic vision is functionally comparable to that of younger observers in many respects. For example, both age groups exhibited a similar ability to discriminate depth and surface shape. The results also showed, however, that age-related differences in stereopsis do exist, and they become most noticeable when the older stereoscopic system is challenged by multiple simultaneous factors.

Cataracts

MedlinePlus

... Oncology Oculoplastics/Orbit Refractive Management/Intervention Retina/Vitreous Uveitis Focus On Pediatric Ophthalmology ... Are Cataracts? Pediatric Cataracts Cataract Diagnosis and Treatment Cataract Surgery IOL Implants: Lens Replacement After Cataracts ...

Treatment of ligneous conjunctivitis with amniotic membrane transplantation and topical cyclosporine

PubMed Central

Tok, Ozlem Yalcin; Kocaoglu, Fatma Akbas; Tok, Levent; Burcu, Ayse; Ornek, Firdevs

2012-01-01

Ligneous conjunctivitis (LC) is a rare form of bilateral chronic recurrent disease in which thick membranes form on the palpebral conjunctiva and other mucosal sites. We report the clinical features and describe the management of two cases. Case 1 was an 8-month-old patient with bilateral membranous conjunctivitis. Case 2 was a 5-year-old patient with unilateral membranous conjunctivitis, esotropia, mechanical ptosis and complicated cataract, and had been treated with a number of medications. Histological investigation of the membrane in both cases showed LC. Treatments with amniotic membrane transplantation and institution of topical cyclosporine have shown good response. There has been complete resolution of the membranes with no recurrence at the end of 40- and 28-month follow-ups, respectively. No treatment related side effects were seen. Thus, it appears that amniotic membrane transplantation and topical cyclosporine are effective alternatives for the treatment of LC. PMID:23202401

Autosomal dominant congenital nuclear cataracts in strain 13/N guinea pigs.

PubMed

Amsbaugh, D F; Stone, S H

1984-01-01

Bilateral cataracts observed in the eyes of a 13/N guinea pig and one of her two offspring led to studies to determine the nature of this cataract and its possible heritability. The cataract was determined to be of the nuclear type, was congenital, and apparently transmitted by a single autosomal dominant gene. The cataractous condition of the mother had no effect on the percentage of litters containing stillborns. The cataractous condition of the offspring had no effect on their viability in utero, i.e., there was no greater incidence of stillborns among cataractous than among non-cataractous offspring. The birthweights of the cataractous animals were lower, but not significantly, than those of their non-cataractous littermates; however, the survivability to weaning of the cataractous offspring was reduced significantly when compared to their non-cataractous siblings.

Suppression of metabolic activity caused by infantile strabismus and strabismic amblyopia in striate visual cortex of macaque monkeys.

PubMed

Wong, Agnes M F; Burkhalter, Andreas; Tychsen, Lawrence

2005-02-01

Suppression is a major sensorial abnormality in humans and monkeys with infantile strabismus. We previously reported evidence of metabolic suppression in the visual cortex of strabismic macaques, using the mitochondrial enzyme cytochrome oxidase as an anatomic label. The purpose of this study was to further elucidate alterations in cortical metabolic activity, with or without amblyopia. Six macaque monkeys were used in the experiments (four strabismic and two control). Three of the strabismic monkeys had naturally occurring, infantile strabismus (two esotropic, one exotropic). The fourth strabismic monkey had infantile microesotropia induced by alternating monocular occlusion in the first months of life. Ocular motor behaviors and visual acuity were tested after infancy in each animal, and development of stereopsis was recorded during infancy in one strabismic and one control monkey. Ocular dominance columns (ODCs) of the striate visual cortex (area V1) were labeled using cytochrome oxidase (CO) histochemistry alone, or CO in conjunction with an anterograde tracer ([H 3 ]proline or WGA-HRP) injected into one eye. Each of the strabismic monkeys showed inequalities of metabolic activity in ODCs of opposite ocularity, visible as rows of lighter CO staining, corresponding to ODCs of lower metabolic activity, alternating with rows of darker CO staining, corresponding to ODCs of higher metabolic activity. In monkeys who had infantile strabismus and unilateral amblyopia, lower metabolic activity was found in (suppressed) ODCs driven by the nondominant eye in each hemisphere. In monkeys who had infantile esotropia and alternating fixation (no amblyopia), metabolic activity was lower in ODCs driven by the ipsilateral eye in each hemisphere. The suppression included a monocular core zone at the center of ODCs and binocular border zones at the boundaries of ODCs. This suppression was not evident in the monocular lamina of the LGN, indicating an intracortical rather than subcortical mechanism. Suppression of metabolic activity in ODCs of V1 differs depending upon whether infantile strabismus is alternating or occurs in conjunction with unilateral amblyopia. Our findings reinforce the principle that unrepaired strabismus promotes abnormal competition in V1, observable as interocular suppression of ODCs.

Paradoxical monocular stereopsis and perspective vergence

NASA Technical Reports Server (NTRS)

Enright, J. T.

1989-01-01

The question of how to most effectively convey depth in a picture is a multifaceted problem, both because of potential limitations of the chosen medium (stereopsis, image motion), and because effectiveness can be defined in various ways. Practical applications usually focus on information transfer, i.e., effective techniques for evoking recognition of implied depth relationships, but this issue depends on subjective judgements which are difficult to scale when stimuli are above threshold. Two new approaches to this question are proposed here which are based on alternative criteria for effectiveness. Paradoxical monocular stereopsis is a remarkably compelling impression of depth which is evoked during one-eyed viewing of only certain illustrations; it can be unequivocally recognized because the feeling of depth collapses when one shifts to binocular viewing. An exploration of the stimulus properties which are effective for this phenomenon may contribute useful answers for the more general perceptual problem. Positive vergence is an eye-movement response associated with changes of fixation point within a picture which implies depth; it also arises only during monocular viewing. The response is directionally appropriate (i.e., apparently nearer objects evoke convergence, and vice versa), but the magnitude of the response can be altered consistently by making relatively minor changes in the illustration. The cross-subject agreement in changes of response magnitude would permit systematic exploration to determine which stimulus configurations are most effective in evoking perspective vergence, with quantitative answers based upon this involuntary reflex. It may well be that most effective pictures in this context will embody features which would increase effectiveness of pictures in a more general sense.

Comparison of a hydrogel corneal inlay and monovision laser in situ keratomileusis in presbyopic patients: focus on visual performance and optical quality.

PubMed

Verdoorn, Cornelis

2017-01-01

To compare the visual performance and optical quality after Raindrop Near Vision Inlay implantation or monovision LASIK for the correction of presbyopia. In this retrospective case-series study, patients previously treated in the nondominant eye with monovision LASIK were compared with patients previously implanted with Raindrop Near Vision Inlay. The study enrolled 16 inlay and 15 monovision LASIK patients. Uncorrected near visual acuity, uncorrected distance visual acuity, binocular stereopsis, patient satisfaction, and patient task performance were assessed. Postoperatively, the mean spherical equivalent was -0.66 D (0.78 SD) for the inlay group and -1.03 D (0.56 SD) for the monovision LASIK group. Monocularly, at uncorrected near distances, 60% of inlay patients and 47% of monovision LASIK patients achieved ≥20/20. Monocularly, at uncorrected far distances, 75% of inlay patients and 40% of monovision LASIK patients achieved ≥20/32 vision. Binocularly, at near distances, 79% of inlay patients and 53% of monovision LASIK patients obtained ≥20/20 vision. All patients achieved ≥20/20 binocularly for distance. On average, inlay patients obtained 98 seconds of arc and monovision LASIK patients obtained 286 seconds of arc for stereopsis. Most (79%) of the inlay patients and 66% of monovision LASIK patients were satisfied with their near vision, while 86% of inlay patients and 67% of monovision LASIK patients were satisfied with their distance vision. Patients receiving corneal inlays demonstrated better near and distance visual acuities, binocular stereopsis, task performance, and satisfaction, when compared to patients treated with monovision LASIK.

Pseudoexfoliation in southern India: the Andhra Pradesh Eye Disease Study.

PubMed

Thomas, Ravi; Nirmalan, Praveen Kumar; Krishnaiah, Sannapaneni

2005-04-01

To report the prevalence of pseudoexfoliation (PXF) and its associations with ocular diseases in a south Indian population. This was a population-based, cross-sectional epidemiologic study in the south Indian state of Andhra Pradesh (AP). A total of 10,293 subjects of all ages from one urban and three rural areas representative of the population of AP were interviewed and underwent a comprehensive ophthalmic evaluation. PXF was diagnosed on slit lamp biomicroscopy by the presence of white dandruff-like material in the pupillary margin, on the trabecular meshwork, and/or on the anterior lens capsule of one or both eyes. The age-gender-area-adjusted overall prevalence of PXF was 0.69% (95% CI: 0.53-0.86). The prevalence of PXF increased with increasing age: 3.01% (95% CI: 2.45-3.80), in those 40 years of age or older, and 6.28% (95% CI: 4.80-7.76), in those 60 years of age or older. The prevalence of PXF was significantly higher among people whose occupation involved outdoor activities (adjusted odds ratio [OR], 2.14; 95% CI: 1.10-4.16). After adjustment for age, the prevalence of PXF was significantly higher in those with nuclear cataract (adjusted OR, 2.00; 95% CI: 1.13-3.54). PXF was significantly associated with blindness (adjusted OR, 2.19; 95% CI: 1.16-4.13). Fifteen (20.5%; 95% CI: 11.20-29.80) of those with PXF were blind, with age-adjusted relative risk (RR) = 4.25 (95% CI: 4.01-4.51). Unilateral blindness (41.2%; 95% CI: 29.81-52.39) and visual impairment (45.21%; 95% CI: 34.29-57.13) were also more common with PXF. Four subjects (5.5%; 95% CI: 0.27-10.2) of those with PXF had glaucoma. The prevalence of PXF in those with glaucoma was 4.2%; (95% CI: 0.17-8.23). In general linear models, the estimated mean +/- SE of IOP with glaucoma and PXF was 24.14 +/- 1.41 mm Hg and was 18.94 +/- 0.26 mm Hg with glaucoma in the absence of PXF; the difference was statistically significant (P < 0.0001). The association of PXF with blindness and aging has public health implications for India. This is especially so considering the burden of cataract with aging and the association of PXF with cataract as well as complications of cataract surgery. The diagnosis of PXF may also be important in the management of glaucoma in this population.

Bilateral cataract extraction with posterior chamber intraocular lens implantation simultaneous in pediatric cataracts.

PubMed

Caça, Ihsan; Sakalar, Yildirim Bayezit; Ari, Seyhmus; Alakus, Fuat; Dogan, Eyüp

2008-01-01

We evaluated the results of simultaneous bilateral cataract extraction with intraocular lens (IOL) inplantation 32 pediatric cataract patients. Simultaneous cataract extraction and posterior capsulotomy with anterior vitrectomy and IOL implantation is an effective and safe procedure in bilateral pediatric cataracts treatment.

[Evaluation of visual functions in elderly patients with femoral neck fracture].

PubMed

Oner, Mithat; Oner, Ayşe; Güney, Ahmet; Halici, Mehmet; Arda, Hatice; Bilal, Okkeş

2009-01-01

We aimed at assessing the visual functions in elderly patients with femoral neck fracture and to compare the results with age-matched controls in this three-year prospective study. Seventy-one patients with a history of fall related hip fracture (39 females, 32 males; mean age 76.3+/-9.7 years; range 64 to 90 years) and who were diagnosed with femoral neck fracture after direct graphy were treated by means of bipolar partial prosthesis and they were contacted postoperatively or prior to discharge to participate in the study. Visual acuity, depth perception, the presence of cataract in the red reflex were evaluated. A dilated fundus and slit-lamp examination were performed if possible. On completion of the examination, the ophthalmologist documented the causes of any visual impairment found. Control group was comprised of age-matched 40 subjects (22 females, 18 males; mean age 73.2+/-7.6 years; range 62 to 90 years) who applied to ophtalmology clinic for routine examination. The visual acuity was significantly decreased in the patient group as was stereopsis (p<0.05). We found no difference between the study group and the controls when we evaluate the distribution of self reported eye disease and eye disease found on ocular examination. The rate of cases who reported not usually wearing glasses was 35% while it was 5% in the control group. When we evaluate the time since last examination, 38% of cases had not had an eye examination for over four years, as compared with 22.5% of controls. This study shows that elderly people should have their eyes tested at least once every two years, refractive errors should be corrected and eye diseases should be treated to decrease the risk of fall-related femoral neck fractures.

Cataracts in congenital toxoplasmosis.

PubMed

Arun, Veena; Noble, A Gwendolyn; Latkany, Paul; Troia, Robert N; Jalbrzikowski, Jessica; Kasza, Kristen; Karrison, Ted; Cezar, Simone; Sautter, Mari; Greenwald, Mark J; Mieler, William; Mets, Marilyn B; Alam, Ambereen; Boyer, Kenneth; Swisher, Charles N; Roizen, Nancy; Rabiah, Peter; Del Monte, Monte A; McLeod, Rima

2007-12-01

To determine the incidence and natural history of cataracts in children with congenital toxoplasmosis. Children referred to the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS) between 1981 and 2005 were examined by ophthalmologists at predetermined times according to a specific protocol. The clinical course and treatment of patients who developed cataracts were reviewed. In the first year of life, 134 of 173 children examined were treated with pyrimethamine, sulfadiazine, and leukovorin, while the remaining 39 were not treated. Cataracts occurred in 27 eyes of 20 patients (11.6%, 95% confidence interval [7.2%, 17.3%]). Fourteen cataracts were present at birth and 13 developed postnatally. Locations of the cataracts included anterior polar (three eyes), anterior subcapsular (six eyes), nuclear (five eyes), posterior subcapsular (seven eyes), and unknown (six eyes). Thirteen cataracts were partial, nine total, and five with unknown complexity. Twelve cataracts remained stable, 12 progressed, and progression was not known for 3. Five of 27 eyes had cataract surgery, with 2 of these developing glaucoma. Sixteen eyes of 11 patients had retinal detachment and cataract. All eyes with cataracts had additional ocular lesions. In the NCCCTS cohort, 11.6% of patients were diagnosed with cataracts. There was considerable variability in the presentation, morphology, and progression of the cataracts. Associated intraocular pathology was an important cause of morbidity.

Biometry and clinical characteristics of congenital cataracts and microphthalmia in the Miniature Schnauzer.

PubMed

Gelatt, K N; Samuelson, D A; Barrie, K P; Das, N D; Wolf, E D; Bauer, J E; Andresen, T L

1983-07-01

Forty-two Miniature Schnauzer pups and adults with congenital cataracts and microphthalmia were evaluated by serial ophthalmic examinations, slit lamp biomicroscopic photography, and A-scan ultrasonography. The cataracts were evident when the eyelids opened at 2 weeks, affecting predominantly the lens nucleus and posterior cortex. Lenticonus was evident in 19% of the cataractous lenses. Progression of the cataracts was variable and related to involvement of the equatorial and posterior cortices. Lens-induced uveitis developed in some adult dogs with advanced hypermature cataracts. The globe and lens were smaller than normal in the cataractous eyes, as ascertained by A-scan ultrasonography. Age-matched comparisons of clear lens carrier Miniature Schnauzers and normal Beagles with the cataractous Miniature Schnauzers indicated affected globes and cataractous lenses were reduced 10% to 20% in their anteroposterior lengths. The microphthalmia appeared related to the congenital microphakic cataract.

Cataract surgery practices in the United States Veterans Health Administration.

PubMed

Havnaer, Annika G; Greenberg, Paul B; Cockerham, Glenn C; Clark, Melissa A; Chomsky, Amy

2017-04-01

To describe current cataract surgery practices within the United States Veterans Health Administration (VHA). Veterans Health Administration hospitals in the U.S. Retrospective data analysis. An initial e-mail containing a link to an anonymous 32-question survey of cataract surgery practices was sent to participants in May 2016. Two reminder e-mails were sent to nonresponders 1 week and 2 weeks after the initial survey was sent; the remaining nonresponders were called twice over a 2-week period. The data were analyzed using descriptive statistics. The response rate was 75% (67/89). Cataract surgeons routinely ordered preoperative testing in 29 (45%) of 65 sections and preoperative consultations in 26 (39%) of 66 sections. In 22 (33%) of 66 sections, cataract surgeons administered intracameral antibiotics. In 61 (92%) of 66 sections, cataract surgeons used toric intraocular lenses (IOLs). In 20 (30%) of 66 sections, cataract surgeons used multifocal IOLs. Cataract surgeons in 6 (9%) of 66 sections performed femtosecond laser-assisted cataract surgery. In 6 (9%) of 66 sections, cataract surgeons performed immediate sequential bilateral cataract surgery. Forty-nine (74%) ophthalmology chiefs reported a high level of satisfaction with Veterans Affairs ophthalmology. The survey results indicate that in cataract surgery in the VHA, routine preoperative testing is commonly performed and emerging practices, such as femtosecond laser-assisted cataract surgery and immediate sequential bilateral cataract surgery, have limited roles. The results of this survey could benchmark future trends in U.S. cataract surgery practices, especially in teaching hospital settings. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Femtosecond laser-assisted compared with standard cataract surgery for removal of advanced cataracts.

PubMed

Hatch, Kathryn M; Schultz, Tim; Talamo, Jonathan H; Dick, H Burkhard

2015-09-01

To compare effective phacoemulsification time (EPT) for the removal of brunescent cataracts treated with femtosecond laser-assisted cataract surgery with standard cataract phacoemulsification techniques. Ruhr University Eye Hospital, Bochum, Germany. Comparative prospective case study. The Lens Opacities Classification System III (LOCS III) grading system was used to measure eyes divided into 4 groups having cataract surgery. Groups 1 and 2 contained eyes with LOCS III grade nuclear opalescence (NO) 3 cataracts treated with standard cataract surgery and femtosecond laser-assisted cataract surgery, respectively. Groups 3 and 4 contained brunescent cataracts, LOCS III grades NO5, treated with standard cataract surgery and femtosecond laser-assisted cataract surgery, respectively. There were 240 eyes, with 60 eyes in each group. The EPT in Group 1 ranged from 0.46 to 3.10 (mean 1.38); the EPT in all eyes in Group 2 was 0 (P < .001). The EPT in Groups 3 and 4 was 2.12 to 19.29 (mean 6.85) and 0 to 6.75 (mean 1.35), respectively (P < .001). A comparison between EPT in Groups 1 and 4 showed that EPT in Group 4 was also lower than in Group 1 (P = .013). Groups 4 and 1 were the most statistically similar of all groups compared, suggesting that EPT for a femtosecond laser-treated grade 5 cataract was most similar to that of a standard-treated grade 3 cataract. Femtosecond laser pretreatment for brunescent cataracts allowed for a significant reduction in EPT compared with manual standard phacoemulsification techniques. Drs. Hatch, Talamo, and Dick are consultants to Abbott Medical Optics, Inc. Dr. Schultz has no financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Cataract prevalence varies substantially with assessment systems: comparison of clinical and photographic grading in a population-based study.

PubMed

Tan, Anna C S; Wang, Jie Jin; Lamoureux, Ecosse L; Wong, Wanling; Mitchell, Paul; Li, Jialiang; Tan, Ava Grace; Wong, Tien Y

2011-08-01

Cataract is the major cause of blindness worldwide yet there is no consensus on its assessment and definition. This study compares age-related cataract prevalence derived from two commonly used methods: clinical assessment using the Lens Opacity Classification System (LOCS III) and photographic grading using the Wisconsin Cataract Grading System (Wisconsin System). The Singapore Malay Eye Study is a population-based study of 3,280 Singapore Malays aged 40-80 years. Presence of nuclear, cortical and posterior sub-capsular cataract was assessed clinically during slit-lamp examination using LOCS III, and via slit-lamp and retro-illumination photographic grading using the Wisconsin System. Analyses were conducted to determine agreement in cataract prevalence estimates between the two grading Systems and approaches. Poor agreement was found between severity levels of the two grading scales for all three cataract types. Using currently accepted cut-offs to define nuclear (≥ 4 on both LOCS III and Wisconsin System), cortical (≥ 2 in LOCS III, ≥ 25% in Wisconsin) and PSC (≥ 2 in LOCS III, ≥ 5 % in Wisconsin) cataract, the LOCS III overestimated the prevalence of significant cataract as compared to the Wisconsin System, with nuclear cataract prevalence, 27.5% (LOCS III) versus 17.0% (Wisconsin System), cortical cataract prevalence, 27.9% versus 7.0% and posterior sub-capsular cataract prevalence, 7.8% versus 5.1%. The prevalence of cataract in a population varies substantially by measurement methods, with systematically different estimates found using the two most frequent cataract grading systems. This study re-emphasizes the need for global standards to assess and define cataract for epidemiologic and clinical studies.

Smoking, socioeconomic factors, and age-related cataract: The Singapore Malay Eye study.

PubMed

Wu, Renyi; Wang, Jie Jin; Mitchell, Paul; Lamoureux, Ecosse L; Zheng, Yingfeng; Rochtchina, Elena; Tan, Ava G; Wong, Tien Yin

2010-08-01

To describe the relationship of smoking, sex, and socioeconomic factors with age-related cataract in Malay adults in Singapore. In a population-based study, 3280 Malay individuals aged 40 to 80 years participated (78.7% response rate). All had interviews, systemic examination, and laboratory investigations. Lens opacity was graded from slitlamp and retroillumination photographs using the Wisconsin Cataract Grading System. Smoking-cataract associations were compared with the Blue Mountains Eye Study in Australia. Of 2927 participants (89.2%) with gradable lens photographs, 1338 (45.7%) had cataract. After adjusting for age, sex, body mass index, hypertension, and diabetes, current smokers had a higher prevalence of nuclear cataract (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.46-2.98), cortical cataract (OR, 1.33; 95% CI, 1.02-1.74), posterior subcapsular cataract (OR, 1.39; 95% CI, 1.02-1.91), or any cataract (OR, 1.48; 95% CI, 1.10-1.99). These associations were not seen in the Blue Mountains Eye Study. Primary or lower education (OR, 1.67; 95% CI, 1.06-2.64) and low monthly income (OR, 1.43; 95% CI, 1.09-1.87) were both associated with nuclear cataract, while small-sized public housing was associated with posterior subcapsular cataract (OR, 1.70; 95% CI, 1.28-2.25). Among men, 43.5% currently smoked compared with only 3.2% of women. The population attributable risk of nuclear cataract due to smoking was estimated to be 17.6% in men. Smoking and indicators of low socioeconomic status were associated with cataract in Malay persons, with 1 in 6 nuclear cataract cases in men attributable to smoking. Smoking-cataract associations were stronger in Malay than in white persons.

A new computer program for mass screening of visual defects in preschool children.

PubMed

Briscoe, D; Lifshitz, T; Grotman, M; Kushelevsky, A; Vardi, H; Weizman, S; Biedner, B

1998-04-01

To test the effectiveness of a PC computer program for detecting vision disorders which could be used by non-trained personnel, and to determine the prevalence of visual impairment in a sample population of preschool children in the city of Beer-Sheba, Israel. 292 preschool children, aged 4-6 years, were examined in the kindergarten setting, using the computer system and "gold standard" tests. Visual acuity and stereopsis were tested and compared using Snellen type symbol charts and random dot stereograms respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and kappa test were evaluated. A computer pseudo Worth four dot test was also performed but could not be compared with the standard Worth four dot test owing to the inability of many children to count. Agreement between computer and gold standard tests was 83% and 97.3% for visual acuity and stereopsis respectively. The sensitivity of the computer stereogram was only 50%, but it had a specificity of 98.9%, whereas the sensitivity and specificity of the visual acuity test were 81.5% and 83% respectively. The positive predictive value of both tests was about 63%. 27.7% of children tested had a visual acuity of 6/12 or less and stereopsis was absent in 28% using standard tests. Impairment of fusion was found in 5% of children using the computer pseudo Worth four dot test. The computer program was found to be stimulating, rapid, and easy to perform. The wide availability of computers in schools and at home allow it to be used as an additional screening tool by non-trained personnel, such as teachers and parents, but it is not a replacement for standard testing.

Latent stereopsis for motion in depth in strabismic amblyopia.

PubMed

Hess, Robert F; Mansouri, Behzad; Thompson, Benjamin; Gheorghiu, Elena

2009-10-01

To investigate the residual stereo function of a group of 15 patients with strabismic amblyopia, by using motion-in-depth stimuli that allow discrimination of contributions from local disparity as opposed to those from local velocity mechanisms as a function of the rate of depth change. The stereo performance (percentage correct) was measured as a function of the rate of depth change for dynamic random dot stimuli that were either temporally correlated or uncorrelated. Residual stereoscopic function was demonstrated for motion in depth based on local disparity information in 2 of the 15 observers with strabismic amblyopia. The use of a neutral-density (ND) filter in front of the fixing eye enhanced motion-in-depth performance in four subjects randomly selected from the group that originally displayed only chance performance. This finding was true across temporal rate and for correlated and uncorrelated stimuli, suggesting that it was disparity based. The opposite occurred in a group of normal subjects. In a separate experiment, the hypothesis was that the beneficial effect of the ND filter is due to its contrast and/or mean luminance-reducing effects rather than any interocular time delay that it may introduce and that it is specific to motion-in-depth performance, as similar improvements were not found for static stereopsis. A small proportion of observers with strabismic amblyopia exhibit residual performance for motion in depth, and it is disparity based. Furthermore, some observers with strabismic amblyopia who do not display any significant stereo performance for motion in depth under normal binocular viewing may display above-chance stereo performance if the degree of interocular suppression is reduced. The authors term this phenomenon latent stereopsis.

Effects of strabismic amblyopia and strabismus without amblyopia on visuomotor behavior, I: saccadic eye movements.

PubMed

Niechwiej-Szwedo, Ewa; Chandrakumar, Manokaraananthan; Goltz, Herbert C; Wong, Agnes M F

2012-11-01

It has previously been shown that anisometropic amblyopia affects the programming and execution of saccades. The aim of the current study was to investigate the impact of strabismic amblyopia on saccade performance. Fourteen adults with strabismic amblyopia, 13 adults with strabismus without amblyopia, and 14 visually normal adults performed saccades and reach-to-touch movements to targets presented at ± 5° and ± 10° eccentricity during binocular and monocular viewing. Latency, amplitude, and peak velocity of primary and secondary saccades were measured. In contrast to visually normal participants who had shorter primary saccade latency during binocular viewing, no binocular advantage was found in patients with strabismus with or without amblyopia. Patients with amblyopia had longer saccade latency during amblyopic eye viewing (P < 0.0001); however, there were no significant differences in saccade amplitude precision among the three groups across viewing conditions. Further analysis showed that only patients with severe amblyopia and no stereopsis (n = 4) exhibited longer latency (which was more pronounced for more central targets; P < 0.0001), and they also had reduced amplitude precision during amblyopic eye viewing. In contrast, patients with mild amblyopia (n = 5) and no stereopsis had normal latency and reduced precision during amblyopic eye viewing (P < 0.001), whereas those with gross stereopsis (n = 5) had normal latency and precision. There were no differences in peak velocity among the groups. Distinct patterns of saccade performance according to different levels of visual acuity and stereoscopic losses in strabismic amblyopia were found. These findings were in contrast to those in anisometropic amblyopia in which the altered saccade performance was independent of the extent of visual acuity or stereoscopic deficits. These results were most likely due to different long-term sensory suppression mechanisms in strabismic versus anisometropic amblyopia.

Partial correction of irregular aniseikonia secondary to retinal traction.

PubMed

Currie, Debra

2012-07-01

This case report presents the management of symptomatic retinally induced aniseikonia and a short review of the literature pertaining to two clinical tests used in the measurement and management of aniseikonia. The clinician is also provided a review of how to design eikonic lenses. A 30-year-old white male presented with symptoms of perceived image size difference after scleral buckle repair for retinal detachment in the right eye. Three measures of aniseikonia resulted in markedly different values, but all indicated larger perceived left eye image. Stereopsis was measured before and after placing an afocal magnifying lens over the right eye. Stereopsis improved immediately upon placement of the afocal lens, with further improvement after 20 minutes, and stereopsis decreased upon removal. The patient reported improved visual comfort for near work with the afocal lens. Eikonic glasses were designed, and the patient reported improved comfort for near work that has remained for over 1 year of wear. Studies evaluating the validity and reliability of the New Aniseikonia Test and the Aniseikonia Inspector are reviewed. Most studies report that induced aniseikonia is underestimated. This case report illustrates that despite the problem with underestimation, these tests are useful clinical tools to identify whether aniseikonia exists and which eye has the larger perceived image. Results can be used as a starting point when making clinical decisions about managing aniseikonia. The Aniseikonia Inspector also assists in the design of eikonic glasses. Even when aniseikonia is substantial, variable in magnitude, and irregular due to retinal disease, reducing the overall aniseikonia can improve binocularity and patient's comfort noticeably for the long term. The underestimation of induced aniseikonia in clinical tests does not preclude their use as a tool in the management of symptomatic aniseikonia.

Cat-Map: putting cataract on the map

PubMed Central

Bennett, Thomas M.; Hejtmancik, J. Fielding

2010-01-01

Lens opacities, or cataract(s), may be inherited as a classic Mendelian disorder usually with early-onset or, more commonly, acquired with age as a multi-factorial or complex trait. Many genetic forms of cataract have been described in mice and other animal models. Considerable progress has been made in mapping and identifying the genes and mutations responsible for inherited forms of cataract, and genetic determinants of age-related cataract are beginning to be discovered. To provide a convenient and accurate summary of current information focused on the increasing genetic complexity of Mendelian and age-related cataract we have created an online chromosome map and reference database for cataract in humans and mice (Cat-Map). PMID:21042563

Cataract surgery among Medicare beneficiaries.

PubMed

Schein, Oliver D; Cassard, Sandra D; Tielsch, James M; Gower, Emily W

2012-10-01

To present descriptive epidemiology of cataract surgery among Medicare recipients in the United States. Cataract surgery performed on Medicare beneficiaries in 2003 and 2004. Medicare claims data were used to identify all cataract surgery claims for procedures performed in the United States in 2003-2004. Standard assumptions were used to limit the claims to actual cataract surgery procedures performed. Summary statistics were created to determine the number of procedures performed for each outcome of interest: cataract surgery rates by age, sex, race and state; surgical volume by facility type and surgeon characteristics; time interval between first- and second-eye cataract surgery. The national cataract surgery rate for 2003-2004 was 61.8 per 1000 Medicare beneficiary person-years. The rate was significantly higher for females and for those aged 75-84 years. After adjustment for age and sex, blacks had approximately a 30% lower rate of surgery than whites. While only 5% of cataract surgeons performed more than 500 cataract surgeries annually, these surgeons performed 26% of the total cataract surgeries. Increasing surgical volume was found to be highly correlated with use of ambulatory surgical centers and reduced time interval between first- and second-eye surgery in the same patient. The epidemiology of cataract surgery in the United States Medicare population documents substantial variation in surgical rates by race, sex, age, and by certain provider characteristics.

Elimination of avoidable blindness due to cataract: Where do we prioritize and how should we monitor this decade?

PubMed Central

Murthy, Gudlavalleti V S; John, Neena; Shamanna, Bindiganavale R; Pant, Hira B

2012-01-01

Background: In the final push toward the elimination of avoidable blindness, cataract occupies a position of eminence for the success of the Right to Sight initiative. Aims: Review existing situation and assess what monitoring indicators may be useful to chart progress towards attaining the goals of Vision 2020. Settings and Design: Review of published papers from low and middle income countries since 2000. Materials and Methods: Published population-based data on prevalence of cataract blindness/visual impairment were accessed and prevalence of cataract blindness/visual impairment computed, where not reported. Data on prevalence of cataract blindness, cataract surgical coverage at different visual acuity cut offs, surgical outcomes, and prevalence of cataract surgery were analyzed. Scatter plots were used to look at relationships of some variables, with Human Development Index (HDI) rank. Available data on Cataract Surgical Rate (CSR) was plotted against prevalence of cataract surgery reported from surveys. Results: Worse HDI Ranks were associated with higher prevalence of cataract blindness. Most studies showed that a significant proportion of the blind were covered by surgery, while a fifth showed that a significant proportion, were operated before they went blind. A good visual outcome after surgery was positively correlated with higher surgical coverage. CSR was positively correlated with cataract surgical coverage. Conclusions: Cataract surgical coverage is increasing in most countries at vision <3/60 and visual outcomes after cataract surgery are improving. Establishing population-based surveillance of cataract surgical need and performance is a strong monitoring tool and will help program planners immensely. PMID:22944756

First and second eye cataract surgery and driver self-regulation among older drivers with bilateral cataract: a prospective cohort study.

PubMed

Agramunt, Seraina; Meuleners, Lynn B; Fraser, Michelle L; Chow, Kyle C; Ng, Jonathon Q; Raja, Vignesh

2018-02-17

Driving a car is the most common form of transport among the older population. Common medical conditions such as cataract, increase with age and impact on the ability to drive. To compensate for visual decline, some cataract patients may self-regulate their driving while waiting for cataract surgery. However, little is known about the self-regulation practices of older drivers throughout the cataract surgery process. The aim of this study is to assess the impact of first and second eye cataract surgery on driver self-regulation practices, and to determine which objective measures of vision are associated with driver self-regulation. Fifty-five older drivers with bilateral cataract aged 55+ years were assessed using the self-reported Driving Habits Questionnaire, the Mini-Mental State Examination and three objective visual measures in the month before cataract surgery, at least one to three months after first eye cataract surgery and at least one month after second eye cataract surgery. Participants' natural driving behaviour in four driving situations was also examined for one week using an in-vehicle monitoring device. Two separate Generalised Estimating Equation logistic models were undertaken to assess the impact of first and second eye cataract surgery on driver-self-regulation status and which changes in visual measures were associated with driver self-regulation status. The odds of being a self-regulator in at least one driving situation significantly decreased by 70% after first eye cataract surgery (OR: 0.3, 95% CI: 0.1-0.7) and by 90% after second eye surgery (OR: 0.1, 95% CI: 0.1-0.4), compared to before first eye surgery. Improvement in contrast sensitivity after cataract surgery was significantly associated with decreased odds of self-regulation (OR: 0.02, 95% CI: 0.01-0.4). The findings provide a strong rationale for providing timely first and second eye cataract surgery for older drivers with bilateral cataract, in order to improve their mobility and independence.

Risk of Cataract among Subjects with the Acquired Immune Deficiency Syndrome Free of Ocular Opportunistic Infections

PubMed Central

Kempen, John H.; Sugar, Elizabeth A.; Varma, Rohit; Dunn, James P.; Heinemann, Murk-Hein; Jabs, Douglas A.; Lyon, Alice T.; Lewis, Richard A.

2014-01-01

Purpose To evaluate the risk of cataract in the setting of AIDS. Design Prospective cohort study. Participants Subjects with AIDS free of ocular opportunistic infections throughout catamnesis. Methods During 1998–2008 inclusive, subjects ≥13 years of age were enrolled. Demographic characteristics and clinical characteristics were documented at enrollment and semiannually. Main Outcome Measures Cataract was defined as high-grade lens opacity observed by biomicroscopy and judged to be the cause of a best-corrected visual acuity worse than 20/40. Eyes that underwent cataract surgery during follow-up were considered to have developed cataract prior to the first visit when pseudophakia or aphakia was observed. Results Among 1,606 participants (3,212 eyes), at enrollment 1.9% (95% confidence interval (CI): 1.3%−2.7%) were observed to have cataract or prior cataract surgery. Among the 2,812 eyes initially free of cataract, and followed longitudinally (median follow-up=4.6 years), the incidence of cataract was 0.37%/eye-year (95% CI: 0.26%– 0.53%). In addition to age, significant cataract risk factors included prior cataract in the contralateral eye (adjusted hazard ratio (aHR)=21.6, 95% CI: 10.4–44.8), anterior segment inflammation (aHR=4.40, 95% CI: 1.64–11.9), prior retinal detachment (aHR=4.94, 95% CI: 2.21–11.0), and vitreous inflammation (aHR=7.12, 95% CI: 2.02– 25.0), each studied as a time-updated characteristic. Detectable HIV RNA in peripheral blood was associated with lower risk of cataract at enrollment (adjusted odds ratio=0.32, 95% CI: 0.12–0.80) but not of incident cataract (aHR=1.58, 95% CI: 0.90–2.76). After adjustment for other factors, neither the then current absolute CD4+ T cell count nor antiretroviral therapy status showed consistent association with cataract risk, nor did an additive diagnosis of other other co-morbidities. Compared to the available population-based studies that used similar definitions of cataract, the age-specific prevalence of cataract in our cohort was higher than in one of two such studies, and the age-specific incidence of cataract surgery was higher. Conclusions Our results suggest cataract may occur earlier among patients with AIDS free of ocular opportunistic infections than in the general population. Cataract risk was associated most strongly with age and with other ocular morbidity in this population. With improved survival, the burden of cataract likely will increase for persons with HIV/AIDS. PMID:25109932

Size matters: Perceived depth magnitude varies with stimulus height.

PubMed

Tsirlin, Inna; Wilcox, Laurie M; Allison, Robert S

2016-06-01

Both the upper and lower disparity limits for stereopsis vary with the size of the targets. Recently, Tsirlin, Wilcox, and Allison (2012) suggested that perceived depth magnitude from stereopsis might also depend on the vertical extent of a stimulus. To test this hypothesis we compared apparent depth in small discs to depth in long bars with equivalent width and disparity. We used three estimation techniques: a virtual ruler, a touch-sensor (for haptic estimates) and a disparity probe. We found that depth estimates were significantly larger for the bar stimuli than for the disc stimuli for all methods of estimation and different configurations. In a second experiment, we measured perceived depth as a function of the height of the bar and the radius of the disc. Perceived depth increased with increasing bar height and disc radius suggesting that disparity is integrated along the vertical edges. We discuss size-disparity correlation and inter-neural excitatory connections as potential mechanisms that could account for these results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pictorial communication in virtual and real environments

NASA Technical Reports Server (NTRS)

Ellis, Stephen R. (Editor)

1991-01-01

Papers about the communication between human users and machines in real and synthetic environments are presented. Individual topics addressed include: pictorial communication, distortions in memory for visual displays, cartography and map displays, efficiency of graphical perception, volumetric visualization of 3D data, spatial displays to increase pilot situational awareness, teleoperation of land vehicles, computer graphics system for visualizing spacecraft in orbit, visual display aid for orbital maneuvering, multiaxis control in telemanipulation and vehicle guidance, visual enhancements in pick-and-place tasks, target axis effects under transformed visual-motor mappings, adapting to variable prismatic displacement. Also discussed are: spatial vision within egocentric and exocentric frames of reference, sensory conflict in motion sickness, interactions of form and orientation, perception of geometrical structure from congruence, prediction of three-dimensionality across continuous surfaces, effects of viewpoint in the virtual space of pictures, visual slant underestimation, spatial constraints of stereopsis in video displays, stereoscopic stance perception, paradoxical monocular stereopsis and perspective vergence. (No individual items are abstracted in this volume)

The first cataract surgeons in Latin America: 1611–1830

PubMed Central

Leffler, Christopher T; Wainsztein, Ricardo D

2016-01-01

We strove to identify the earliest cataract surgeons in Latin America. Probably by 1611, the Genovese oculist Francisco Drago was couching cataracts in Mexico City. The surgeon Melchor Vásquez de Valenzuela probably performed cataract couching in Lima by 1697. Juan Peré of France demonstrated cataract couching in Veracruz and Mexico City between 1779 and 1784. Juan Ablanedo of Spain performed couching in Veracruz in 1791. Cataract extraction might have been performed in Havana and Caracas by 1793 and in Mexico by 1797. The earliest contemporaneously documented cataract extractions in Latin America were performed in Guatemala City by Narciso Esparragosa in 1797. In addition to Esparragosa, surgeons born in the New World who established the academic teaching of cataract surgery included José Miguel Muñoz in Mexico and José María Vargas in Caracas. Although cataract surgery came quite early to Latin America, its availability was initially inconsistent and limited. PMID:27143845

Evaluation of antioxidants and argpyrimidine in normal and cataractous lenses in north Indian population

PubMed Central

Mynampati, Bharani K; Ghosh, Sujata; Muthukumarappa, Thungapathra; Ram, Jagat

2017-01-01

AIM To assess the level of glutathione, thioltransferase, and argpyrimidine in nuclear and cortical cataractous lenses as well as in the clear lenses in the north Indian population. METHODS Human cataractous lenses were collected from the patients who underwent extracapsular cataract extraction surgery; clear lenses were collected from the freshly donated eye bank eyes. Antioxidant molecules such as glutathione and thioltransferase enzyme activity were measured; simultaneously in these lenses a blue fluorophore argpyrimidine, an advanced glycation end (AGE) product level was assessed using high performance liquid chromatography (HPLC). RESULTS The protein concentration was found to be present at higher levels in the control lenses compared to cataract lenses. A significant decrease in the glutathione level was observed in the nuclear cataractous lenses compared to cortical cataractous (P=0.004) and clear lenses (P≤0.005), but no significant change in the level of antioxidant enzyme thioltransferase was observed. Further, argpyrimidine a blue fluorophore (AGE) was found to be significantly higher in the nuclear cataract (P=0.013) compared to cortical cataract lenses. CONCLUSION Antioxidants such as glutathione significantly decrease in age-related nuclear and cortical cataract and an AGE, argpyrimidine are present at significantly higher levels in nuclear cataract. PMID:28730112

Differential cataract blindness by sex in India: Evidence from two large national surveys.

PubMed

Pant, Hira B; Bandyopadhyay, Souvik; John, Neena; Chandran, Anil; Gudlavalleti, Murthy Venkata S

2017-02-01

Women suffer disproportionately more from cataract blindness compared to males in low- and middle-income countries. Two large population-based surveys have been undertaken in India at an interval of 7 years and data from these surveys provided an opportunity to assess the trends in gender differentials in cataract blindness. Data were extracted from the surveys to discern sex differences in cataract blindness. Multivariate analysis was performed to adjust for confounders and their impact on gender differences in cataract blindness. Blindness was defined as presenting vision <20/400 in the better eye, and a cataract blind person was defined as a blind person where the principal cause of loss of vision was cataract. Prevalence of cataract blindness was higher in females compared to males in both surveys. The odds of cataract blindness for females did not change over time as observed in the surveys (1999-2001 and 2006-2007). Adjusted odds ratio from logistic regression analysis revealed that females continued to be at a higher risk of cataract blindness. Sex differences continued in India in relation to cataract blindness despite the gains made by the national program.

Intraocular Lens Use in an Astronaut During Long Duration Spaceflight.

PubMed

Mader, Thomas H; Gibson, C Robert; Schmid, Josef F; Lipsky, William; Sargsyan, Ashot E; Garcia, Kathleen; Williams, Jeffrey N

2018-01-01

The purpose of this paper is to report the first use of an intraocular lens (IOL) in an astronaut during long duration spaceflight (LDSF). An astronaut developed a unilateral cataract and underwent phacoemulsification with insertion of an acrylic IOL. Approximately 15 mo later he flew on a Soyuz spacecraft to the International Space Station (ISS), where he successfully completed a 6-mo mission. Ocular examination, including ultrasound (US), was performed before, during, and after his mission and he was questioned regarding visual changes during each portion of his flight. We documented no change in IOL position during his space mission. This astronaut reported excellent and stable vision during liftoff, entry into microgravity (MG), 6 mo on the ISS, descent, and landing. Our results suggest that modern IOLs are stable, effective, and well tolerated during LDSF.Mader TH, Gibson CR, Schmid JF, Lipsky W, Sargsyan AE, Garcia K, Williams JN. Intraocular lens use in an astronaut during long duration spaceflight. Aerosp Med Hum Perform. 2018; 89(1):63-65.

Inverse association of vitamin C with cataract in older people in India.

PubMed

Ravindran, Ravilla D; Vashist, Praveen; Gupta, Sanjeev K; Young, Ian S; Maraini, Giovanni; Camparini, Monica; Jayanthi, R; John, Neena; Fitzpatrick, Kathryn E; Chakravarthy, Usha; Ravilla, Thulasiraj D; Fletcher, Astrid E

2011-10-01

To examine the association between vitamin C and cataract in the Indian setting. Population-based cross-sectional analytic study. A total of 5638 people aged ≥60 years. Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants were measured by reverse-phase high-pressure liquid chromatography. Cataract and type of cataract were graded from digital lens images using the Lens Opacity Classification System III (LOCS III), and cataract was classified from the grade in the worse eye of ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any cataract was defined as any unoperated or operated cataract. Of 7518 enumerated people, 5638 (75%) provided data on vitamin C, antioxidants, and potential confounders. Vitamin C was inversely associated with cataract (adjusted odds ratio [OR] for highest to lowest quartile = 0.61; 95% confidence interval (CI), 0.51-0.74; P=1.1×10(-6)). Inclusion of other antioxidants in the model (lutein, zeaxanthin, retinol, β-carotene, and α-tocopherol) made only a small attenuation to the result (OR 0.68; 95% CI, 0.57-0.82; P < 0.0001). Similar results were seen with vitamin C by type of cataract: nuclear cataract (adjusted OR 0.66; CI, 0.54-0.80; P < 0.0001), cortical cataract (adjusted OR 0.70; CI, 0.54-0.90; P < 0.002), and PSC (adjusted OR 0.58; CI, 0.45-0.74; P < 0.00003). Lutein, zeaxanthin, and retinol were significantly inversely associated with cataract, but the associations were weaker and not consistently observed by type of cataract. Inverse associations were also observed for dietary vitamin C and cataract. We found a strong association with vitamin C and cataract in a vitamin C-depleted population. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Relationship between socioeconomic and lifestyle factors and cataracts in Koreans: the Korea National Health and Nutrition Examination Survey 2008-2011.

PubMed

Nam, G E; Han, K; Ha, S G; Han, B-D; Kim, D H; Kim, Y-H; Cho, K H; Park, Y G; Ko, B-J

2015-07-01

Cataracts are the leading cause of visual impairment and blindness, and therefore early identification and modification of the risk factors for cataracts are meaningful. This study aimed to investigate the relationship between socioeconomic status (SES) and lifestyle factors, and age-related cataracts in South Korea. This cross-sectional study was based on data collected in the 2008-2011 Korea National Health and Nutrition Examination Survey. A total of 15 866 subjects, aged ≥40 years, were included. SES was defined using household income and education level. Sociodemographic, lifestyle, and other associated factors were assessed by health interviews and examinations. Cataracts were diagnosed via slit-lamp examination using the Lens Opacities Classification System III. The prevalence of any cataract was 38.9% in men and 42.3% in women (P<0.001). In women, the risk of cataracts increased with decreases in household income (P-value for trend=0.016 and 0.041 in any, and cortical cataract, respectively) and education level (P-value for trend=0.009, 0.027, and 0.016 in any, nuclear, and cortical cataract, respectively) after adjusting for confounding factors. Current smoking was correlated with nuclear cataracts in men (OR 1.21; 95% CI: 1.00, 1.46 in age-adjusted analysis) and cataract surgery in women (OR 2.25; 95% CI: 1.00, 5.04 in multivariate-adjusted analysis). Socioeconomic disparities in cataract prevalence were observed in women; current smoking increased the risk of nuclear cataracts in men and surgery in women. Public health interventions focusing on gender differences are warranted to prevent and treat cataracts.

Cataract Surgery among Medicare Beneficiaries

PubMed Central

Schein, Oliver D.; Cassard, Sandra D.; Tielsch, James M.; Gower, Emily W.

2014-01-01

Purpose To present descriptive epidemiology of cataract surgery among Medicare recipients in the United States. Setting Cataract surgery performed on Medicare beneficiaries in 2003 and 2004. Methods Medicare claims data were used to identify all cataract surgery claims for procedures performed in the United States in 2003-2004. Standard assumptions were used to limit the claims to actual cataract surgery procedures performed. Summary statistics were created to determine the number of procedures performed for each outcome of interest: cataract surgery rates by age, race, and gender; surgical volume by facility type, surgeon characteristics, and state; time interval between first- and second-eye cataract surgery. Results The national cataract surgery rate for 2003-2004 was 61.8 per 1000 Medicare beneficiary person-years. The rate was significantly higher for females and for those 75-84. After adjustment for age and gender, blacks had approximately a 30% lower rate of surgery than whites. While only 5% of cataract surgeons performed more than 500 cataract surgeries annually, these surgeons performed 26% of the total cataract surgeries. Increasing surgical volume was found to be highly correlated with use of ambulatory surgical centers and reduced time interval between first- and second-eye surgery in the same patient. Conclusions The epidemiology of cataract surgery in the United States Medicare population documents substantial variation in surgical rates by race, gender, age, and by certain provider characteristics. PMID:22978526

Identification of cataract and post-cataract surgery optical images using artificial intelligence techniques.

PubMed

Acharya, Rajendra Udyavara; Yu, Wenwei; Zhu, Kuanyi; Nayak, Jagadish; Lim, Teik-Cheng; Chan, Joey Yiptong

2010-08-01

Human eyes are most sophisticated organ, with perfect and interrelated subsystems such as retina, pupil, iris, cornea, lens and optic nerve. The eye disorder such as cataract is a major health problem in the old age. Cataract is formed by clouding of lens, which is painless and developed slowly over a long period. Cataract will slowly diminish the vision leading to the blindness. At an average age of 65, it is most common and one third of the people of this age in world have cataract in one or both the eyes. A system for detection of the cataract and to test for the efficacy of the post-cataract surgery using optical images is proposed using artificial intelligence techniques. Images processing and Fuzzy K-means clustering algorithm is applied on the raw optical images to detect the features specific to three classes to be classified. Then the backpropagation algorithm (BPA) was used for the classification. In this work, we have used 140 optical image belonging to the three classes. The ANN classifier showed an average rate of 93.3% in detecting normal, cataract and post cataract optical images. The system proposed exhibited 98% sensitivity and 100% specificity, which indicates that the results are clinically significant. This system can also be used to test the efficacy of the cataract operation by testing the post-cataract surgery optical images.

The global state of cataract blindness.

PubMed

Lee, Cameron M; Afshari, Natalie A

2017-01-01

Cataracts are a significant cause of blindness and visual impairment worldwide. The present article reviews the literature and describes the current extent of cataracts globally, barriers to treatment, and recommendations for improving the treatment of cataracts. Prevalence and absolute number of blind because of cataracts remain high, although rates are declining in many areas globally. The age-standardized prevalence of blindness in adults older than 50 remains highest in western sub-Saharan Africa, with a rate of 6.0%. The greatest declines in age-standardized blindness because of cataracts in adults older than 50 between 1990 and 2010 were in East Asia, tropical Latin America, and western Europe. Recent studies have largely found higher rates of cataracts in women than in men. A new simulator for training ophthalmologists in manual small-incision cataract surgery holds promise for the future. The rates of cataract surgery are increasing and postoperative outcomes are improving worldwide, yet challenges to reducing the cataract burden further remain. Cost, an insufficient number of ophthalmologists, and low government funding remain significant barriers but investment in further eye care infrastructure and training of additional ophthalmologists would improve the current situation.

Different alpha crystallin expression in human age-related and congenital cataract lens epithelium.

PubMed

Yang, Jing; Zhou, Sheng; Guo, Minfei; Li, Yuting; Gu, Jianjun

2016-05-28

The purpose of this study was to investigate the different expressions of αA-crystallin and αB-crystallin in human lens epithelium of age-related and congenital cataracts. The central part of the human anterior lens capsule approximately 5 mm in diameter together with the adhering epithelial cells, were harvested and processed within 6 hours after cataract surgery from age-related and congenital cataract patients or from normal eyes of fresh cadavers. The mRNA and soluble protein levels of αA-crystallin and αB-crystallin in the human lens epithelium were detected by real-time PCR and western blots, respectively. The mRNA and soluble protein expressions of αA-crystallin and αB-crystallin in the lens epithelium were both reduced in age-related and congenital cataract groups when compared with the normal control group. However, the degree of α-crystallin loss in the lens epithelium was highly correlated with different cataract types. The α-crystallin expression of the lens epithelium was greatly reduced in the congenital cataract group but only moderately decreased in the age-related cataract group. The reduction of αA-crystallin soluble protein levels in the congenital cataract group was approximately 2.4 fold decrease compared with that of the age-related cataract group, while an mRNA fold change of 1.67 decrease was observed for the age-related cataract group. Similarly, the reduction of soluble protein levels of αB-crystallin in the congenital cataract group was approximately a 1.57 fold change compared with that of the age-related cataract group. A 1.75 fold change for mRNA levels compared with that of the age-related cataract group was observed. The results suggest that the differential loss of α-crystallin in the human lens epithelium could be associated with the different mechanisms of cataractogenesis in age-related versus congenital cataracts, subsequently resulting in different clinical presentations.

Elevated Frequency of Cataracts in Birds from Chernobyl

PubMed Central

Mousseau, Timothy Alexander; Møller, Anders Pape

2013-01-01

Background Radiation cataracts develop as a consequence of the effects of ionizing radiation on the development of the lens of the eye with an opaque lens reducing or eliminating the ability to see. Therefore, we would expect cataracts to be associated with reduced fitness in free-living animals. Methodology/Principal Findings We investigated the incidence of lens opacities typical of cataracts in more than 1100 free-living birds in the Chernobyl region in relation to background radiation. The incidence of cataracts increased with level of background radiation both in analyses based on a dichotomous score and in analyses of continuous scores of intensity of cataracts. The odds ratio per unit change in the regressor was 0.722 (95% CI 0.648, 0.804), which was less than odds ratios from investigations of radiation cataracts in humans. The relatively small odds ratio may be due to increased mortality in birds with cataracts. We found a stronger negative relationship between bird abundance and background radiation when the frequency of cataracts was higher, but also a direct effect of radiation on abundance, suggesting that radiation indirectly affects abundance negatively through an increase in the frequency of cataracts in bird populations, but also through direct effects of radiation on other diseases, food abundance and interactions with other species. There was no increase in incidence of cataracts with increasing age, suggesting that yearlings and older individuals were similarly affected as is typical of radiation cataract. Conclusions/Significance These findings suggest that cataracts are an under-estimated cause of morbidity in free-living birds and, by inference, other vertebrates in areas contaminated with radioactive materials. PMID:23935827

Serum 25-hydroxyvitamin D and Age-Related Cataract.

PubMed

Park, Sangshin; Choi, Nam-Kyong

2017-10-01

Cataract and insufficient vitamin D intake are both increasing worldwide concerns, yet little is known about the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and age-related cataract. We performed this study to determine the association between serum 25(OH)D levels and age-related cataract in adults. Study participants comprised 16,086 adults aged 40 years or older who had never been diagnosed with or undergone surgery for cataract using Korean National Health and Nutrition Examination Survey data from 2008 to 2012. Participants were assessed to have cataract when diagnosed with cortical, nuclear, anterior subcapsular, posterior subcapsular, or mixed cataract. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the magnitude and significance of the association between serum 25(OH)D levels and cataract in multivariable logistic regression models. The OR for nuclear cataract with the highest quintile of serum 25(OH)D levels was 0.86 (95% CI 0.75-0.99) compared to the lowest quintile. A linear trend across quintiles was significant. Natural log-transformed serum 25(OH)D levels were also significantly associated with nuclear cataract (OR 0.84, 95% CI 0.75-0.95). The opulation-attributable fraction of nuclear cataract due to serum 25(OH)D insufficiency (<30 ng/mL) was 8.8% (p = 0.048). Serum 25(OH)D levels were inversely associated with the risk of nuclear cataract. Prospective studies investigating the effects of serum 25(OH)D levels on the development of nuclear cataract are needed to confirm our findings.

Molecular Genetics of Cataract

PubMed Central

Shiels, Alan; Hejtmancik, J. Fielding

2017-01-01

Lens opacities or cataract(s) represent a universally important cause of visual impairment and blindness. Typically, cataract is acquired with aging as a complex disorder involving environmental and genetic risk factors. Cataract may also be inherited with an early onset either in association with other ocular and/or systemic abnormalities or as an isolated lens phenotype. Here we briefly review recent advances in gene discovery for inherited and age-related forms of cataract that are providing new insights into lens development and aging. PMID:26310156

Development of Relative Disparity Sensitivity in Human Visual Cortex.

PubMed

Norcia, Anthony M; Gerhard, Holly E; Meredith, Wesley J

2017-06-07

Stereopsis is the primary cue underlying our ability to make fine depth judgments. In adults, depth discriminations are supported largely by relative rather than absolute binocular disparity, and depth is perceived primarily for horizontal rather than vertical disparities. Although human infants begin to exhibit disparity-specific responses between 3 and 5 months of age, it is not known how relative disparity mechanisms develop. Here we show that the specialization for relative disparity is highly immature in 4- to 6-month-old infants but is adult-like in 4- to 7-year-old children. Disparity-tuning functions for horizontal and vertical disparities were measured using the visual evoked potential. Infant relative disparity thresholds, unlike those of adults, were equal for vertical and horizontal disparities. Their horizontal disparity thresholds were a factor of ∼10 higher than adults, but their vertical disparity thresholds differed by a factor of only ∼4. Horizontal relative disparity thresholds for 4- to 7-year-old children were comparable with those of adults at ∼0.5 arcmin. To test whether infant immaturity was due to spatial limitations or insensitivity to interocular correlation, highly suprathreshold horizontal and vertical disparities were presented in alternate regions of the display, and the interocular correlation of the interdigitated regions was varied from 0% to 100%. This manipulation regulated the availability of coarse-scale relative disparity cues. Adult and infant responses both increased with increasing interocular correlation by similar magnitudes, but adult responses increased much more for horizontal disparities, further evidence for qualitatively immature stereopsis based on relative disparity at 4-6 months of age. SIGNIFICANCE STATEMENT Stereopsis, our ability to sense depth from horizontal image disparity, is among the finest spatial discriminations made by the primate visual system. Fine stereoscopic depth discriminations depend critically on comparisons of disparity relationships in the image that are supported by relative disparity cues rather than the estimation of single, absolute disparities. Very young human and macaque infants are sensitive to absolute disparity, but no previous study has specifically studied the development of relative disparity sensitivity, a hallmark feature of adult stereopsis. Here, using high-density EEG recordings, we show that 4- to 6-month-old infants display both quantitative and qualitative response immaturities for relative disparity information. Relative disparity responses are adult-like no later than 4-7 years of age. Copyright © 2017 the authors 0270-6474/17/375608-12$15.00/0.

A cost and policy analysis comparing immediate sequential cataract surgery and delayed sequential cataract surgery from the physician perspective in the United States.

PubMed

Neel, Sean T

2014-11-01

A cost analysis was performed to evaluate the effect on physicians in the United States of a transition from delayed sequential cataract surgery to immediate sequential cataract surgery. Financial and efficiency impacts of this change were evaluated to determine whether efficiency gains could offset potential reduced revenue. A cost analysis using Medicare cataract surgery volume estimates, Medicare 2012 physician cataract surgery reimbursement schedules, and estimates of potential additional office visit revenue comparing immediate sequential cataract surgery with delayed sequential cataract surgery for a single specialty ophthalmology practice in West Tennessee. This model should give an indication of the effect on physicians on a national basis. A single specialty ophthalmology practice in West Tennessee was found to have a cataract surgery revenue loss of $126,000, increased revenue from office visits of $34,449 to $106,271 (minimum and maximum offset methods), and a net loss of $19,900 to $91,700 (base case) with the conversion to immediate sequential cataract surgery. Physicians likely stand to lose financially, and this loss cannot be offset by increased patient visits under the current reimbursement system. This may result in physician resistance to converting to immediate sequential cataract surgery, gaming, and supplier-induced demand.

Review Recent progress in identification and characterization of loci associated with sex-linked congenital cataract.

PubMed

Zhang, D D; Du, J Z; Topolewski, J; Wang, X M

2016-07-29

Congenital cataract is a common cause of blindness in children; however, its pathogenesis remains unclear. Genetic factors have been shown to play an important role in the pathogenesis of congenital cataract. The current genetic models of congenital cataract include autosomal dominant, autosomal recessive, and sex-linked inheritance. Sex-linked congenital cataract could be inherited through the X or Y chromosome. Congenital cataract is a symptom associated with several X-linked disorders, including Nance-Horan syndrome, Lowe syndrome, Conradi-Hünermann-Happle syndrome, oculo-facio-cardio-dental syndrome, and Alport syndrome. On the other hand, the mechanism and characteristics of Y-linked congenital cataract remains to be identified. Despite its rarity, sex-linked congenital cataract has been known to seriously affect the quality of life of patients. In this review, we present our current understanding of the genes and loci associated with sex-linked congenital cataract. This could help identify novel approaches for the prevention, early diagnosis, and comprehensive disease treatment.

Barriers to Cataract Surgery in Africa: A Systematic Review.

PubMed

Aboobaker, Shaheer; Courtright, Paul

2016-01-01

Cataract remains the leading cause of blindness in Africa. We performed a systematic literature search of articles reporting barriers to cataract surgery in Africa. PubMed and Google Scholar databases were searched with the terms "barriers, cataract, Africa, cataract surgery, cataract surgical coverage (CSC), and rapid assessment of avoidable blindness (RAAB)." The review covered from 1999 to 2014. In RAAB studies, barriers related to awareness and access were more commonly reported than acceptance. Other type of studies reported cost as the most common barrier. Some qualitative studies tended to report community and family dynamics as barriers to cataract surgery. CSC was lower in females in 88.2% of the studies. The variability in outcomes of studies of barriers to cataract surgery could be due to context and the type of data collection. It is likely that qualitative data will provide a deeper understanding of the complex social, family, community, financial and gender issues relating to barriers to uptake of cataract surgery in Africa.

Measuring colour rivalry suppression in amblyopia.

PubMed

Hofeldt, T S; Hofeldt, A J

1999-11-01

To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes. To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed. In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1. 8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (beta=1.21, p<0.0001), and negatively related to stereoacuity (beta=-0.16, p=0.019). The interocular difference in logMAR acuity was negatively related to stereoacuity (beta=-0.13, p=0.009). Colour rivalry suppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.

The lens and cataracts.

PubMed

Matthews, Andrew G

2004-08-01

It is conservatively estimated that some form of lens opacity is present in 5% to 7% of horses with otherwise clinically normal eyes.These opacities can range from small epicapsular remnants of the fetal vasculature to dense and extensive cataract. A cataract is defined technically as any opacity or alteration in the optical homogeneity of the lens involving one or more of the following: anterior epithelium, capsule, cortex, or nucleus. In the horse, cataracts rarely involve the entire lens structure (ie, complete cataracts) and are more usually localized to one anatomic landmark or sector of the lens. Complete cataracts are invariably associated with overt and significant visual disability. Focal or incomplete cataracts alone seldom cause any apparent visual dysfunction in affected horses,however.

A Computer Based Cognitive Simulation of Cataract Surgery

DTIC Science & Technology

2011-12-01

for zonular absence, assess for notable lenticular astigmatism ** How and when do you decide to use a capsular tension ring? (Expert) Zonular...INTRODUCTION The Virtual Mentor Cataract Surgery Trainer is a computer based, cognitive simulation of phacoemulsification cataract surgery. It is...the Cataract Trainer. BODY Phacoemulsification cataract surgery (phaco) is a difficult procedure to learn, with little margin for error. As in other

Blindness and cataract surgical services in Atsinanana region, Madagascar.

PubMed

Randrianaivo, Jean-Baptiste; Anholt, R Michele; Tendrisoa, Diarimirindra Lazaharivony; Margiano, Nestor Jean; Courtright, Paul; Lewallen, Susan

2014-01-01

To assess the prevalence and causes of avoidable blindness in Atsinanana Region, Madagascar, with the Rapid Assessment of Avoidable Blindness (RAAB) survey. We analyzed the hospital records to supplement the findings for public health care planning. Only villages within a two-hour walk from a road, about half of the population of Atsinanana was included. Seventy-two villages were selected by population-proportional-to-size sampling. In each village, compact segment sampling was used to select 50 people over age 50 for eye examination using standard RAAB methods. Records at the two hospitals providing cataract surgery in the region were analyzed for information on patients who underwent cataract surgery in 2010. Cataract incidence rate and target cataract surgery rate (CSR) was modeled from age-specific prevalence of cataract. The participation rate was 87% and the sample prevalence of blindness was 1.96%. Cataract was responsible for 64% and 85.7% of blindness and severe visual impairment, respectively. Visual impairment was due to cataract (69.4%) and refractive error (14.1%). There was a strong positive correlation between cataract surgical rate by district and the proportion of people living within 2 hours of a road. There were marked differences in the profiles of the cataract patients at the two facilities. The estimated incidence of cataract at the 6/18 level was 2.4 eyes per 100 people over age 50 per year. Although the survey included only people with reasonable access, the main cause of visual impairment was still cataract. The incidence of cataract is such that it ought to be possible to eliminate it as a cause of visual impairment, but changes in service delivery at hospitals and strategies to improve access will be necessary for this change.

Aging and Health: Cataracts

MedlinePlus

... Community Home › Aging & Health A to Z › Cataracts Font size A A A Print Share Glossary Basic ... every year in the US. The Most Common Types of Cataracts Cataracts are categorized depending on their ...

Thromboembolism and congenital malformations: from Duane syndrome to thalidomide embryopathy.

PubMed

Parsa, Cameron F; Robert, Matthieu P

2013-04-01

To propose a pathophysiologic mechanism to unify a variety of disparate sporadic congenital malformations. Inductive and deductive analyses to correlate malformation laterality with asymmetries in thoracic anatomy, critical analysis of malformations with female predominance, and concepts of hydrodynamic pressure gradients in vascular growth were applied to the ensuing development of guiding tissue scaffolds for cellular proliferation, differentiation, and apoptosis. Duane syndrome may develop following a focal vascular insult to the sixth nerve trunk with axonal degeneration, allowing for substitutive innervation from third nerve axons to the lateral rectus muscle. Causative fibrin clots may originate from the venous system and paradoxically migrate through physiological right-to left shunts, or they may arise directly from the heart. Hence, the unilateral, left-sided, and female predominance of Duane syndrome results from the asymmetry in the thoracic anatomy and from thrombosis risk factors. Embolic occlusions may also alter local hemodynamic pressure gradients, leading to the compensatory enlargement and persistence of the fetal vasculature and may dysregulate tissue growth. Within the eye, this results in forms of Peters anomaly, unilateral congenital cataracts, and the morning glory disc anomaly, all in the vascular territory of the carotid arteries that also share a propensity for left-sided involvement in girls. Most aberrant misinnervation phenomena (eg, jaw-winking syndrome, crocodile tear syndrome, Brown syndrome, and congenital fibrosis syndrome) and, by extrapolation, the hypoplasia or dysgenesis of noncephalic anatomical structures (including limbs) may be similarly explained. Such malformations will occur more frequently under thrombogenic conditions, such as those induced by thalidomide. Fibrin emboli and focal hypoperfusion may explain the development of many sporadic congenital malformations.

Clinical Features and Complications of the HLA-B27-associated Acute Anterior Uveitis: A Metanalysis.

PubMed

D'Ambrosio, Enzo Maria; La Cava, Maurizio; Tortorella, Paolo; Gharbiya, Magda; Campanella, Michelangelo; Iannetti, Ludovico

2017-01-01

In this article, we report a literature-based metanalysis we have conducted to outline the clinical features of the HLA-B27 Acute Anterior Uveitis (AAU). The examined material was based on observational studies in which participants were affected by Acute Anterior Uveitis and divided into HLA B27+ and HLA B27-. We performed a search on articles with the words "HLA B27 uveitis" dated before May 2014. Among these, 29 articles were selected for a second review. After a further evaluation, 22 articles were analyzed. The clinical characteristics studied in the metanalysis were: (1) systemic disease; (2) sex distribution; (3) laterality; (4) visual acuity; (5) hypopion; (6) anterior chamber's fibrin; (7) elevated intraocular pressure (IOP) during inflammation; (8) glaucoma; (9) posterior synechiae; (10) cataract; (11) cystoid macular edema; (12) papillitis. We have calculated a relative risk (RR) for each outcome measured. The results obtained remark some of the peculiar features linked to the HLA B27 Acute Anterior Uveitis, such as strong association with ankylosing spondylitis (RR = 6.80) and systemic diseases (RR = 9.9), male prevalence (RR = 1.2), unilateral (RR = 1.1) or alternating bilateral (RR = 2.2) involvement, hypopion (RR = 5.5), fibrinous reaction and even papillitis (R = 7.7). Simultaneous bilateral (RR = 0.3) AAU is more frequent in HLA-B27 negative form. We report higher risk of elevated IOP and glaucoma (RR = 0.6) in B27- Acute Anterior Uveitis. No significant difference between HLA B 27 positive and negative AAU was observed according to final visual acuity and complications such as posterior synechiae, cataract, and maculare edema. We trust that this will inform on the clinical evaluation and therapeutic decision in addressing a still ill-defined ophthalmologic condition.

General analysis of factors influencing cataract surgery practice in Shanghai residents.

PubMed

Xu, Yi; He, Jiangnan; Lin, Senlin; Zhang, Bo; Zhu, Jianfeng; Resnikoff, Serge; Lu, Lina; Zou, Haidong

2018-04-18

It was reported that lack of knowledge, less confidence of medical services, commute difficulties, and poor economic conditions would be the main barriers for cataract surgery practice. The influencing factors could have changed in cities with high developing speed. Shanghai is one of the biggest cities in China and the world. The purpose of the study was to explore the factors influencing cataract surgery practice in Shanghai. This was a population-based, cross-sectional study. A total of 2342 cataract patients older than 50 years old with cataract-induced visual impairment or who had undergone cataract surgery were recruited from rural and urban areas of Shanghai. Participants accepted a face-to-face structured questionnaire. Data were collected on patient demographics, education, work, income, health insurance, awareness about cataracts disease, treatment and related medical resources and deration policy, transportation and degree of satisfaction with hospitals. There were 417 patients who had received cataract surgery, 404 of them supplied complete information in the questionnaire. More female subjects (64.6%) than male subjects (35.4%) accepted cataract surgery among the 404 patients. Of the patients with cataract history, 36.4% of surgery patients were equal or older than 80. More people with urban medical insurance received surgery (p = 0.036). Patients who received surgery were more satisfied with local medical service (p = 0.032). In urban area, Lower income and difficulties with commutes were related to a higher rate of surgery. Cataract patients with the following features were more inclined to receive surgery: female, old age, better awareness. In urban areas low income and difficult commutes did not represent barriers for cataract surgery, probably because of appropriate cataract surgery promotion policies recent years in Shanghai. In rural areas, better healthcare reimbursement policies would likely lead to a higher uptake of cataract surgery. Further cohort studies with more controls could supply stronger evidence for our viewpoint.

Understanding Cataract Risk in Aerospace Flight Crew And Review of Mechanisms of Cataract Formation

NASA Technical Reports Server (NTRS)

Jones, Jeffrey A.; McCarten, M.; Manuel, K.; Djojonegoro, B.; Murray, J.; Cucinotta, F.; Feiversen, A.; Wear, M.

2006-01-01

Induction of cataracts by occupational exposure in flight crew has been an important topic of interest in aerospace medicine in the past five years, in association with numerous reports of flight-associated disease incidences. Due to numerous confounding variables, it has been difficult to determine if there is increased cataract risk directly caused by interaction with the flight environment, specifically associated with added radiation exposure during flight. Military aviator records from the United States Air Force (USAF) and Navy (USN) and US astronauts at the National Aeronautics and Space Administration (NASA)/Lyndon B. Johnson Space Center (JSC) were evaluated for the presence, location and age of diagnosis of cataracts. Military aviators were found to have a statistically significant younger average age of onset of their cataracts compared with astronauts, however the incidence density of cataracts was found to be statistically higher in astronauts than in military aviators. USAF and USN aviator s cataracts were most commonly located in the posterior subcapsular region of the lens while astronauts cataracts were most likely to originate generally in the cortical zone. A prospective clinical trial which controls for confounding variables in examination technique, cataract classification, diet, exposure, and pharmacological intervention is needed to determine what percentage of the risk for cataracts are due to radiation, and how to best develop countermeasures to protect flight crews from radiation bioeffects in the future.

Pre-cataract surgery test using speckle pattern

NASA Astrophysics Data System (ADS)

Jutamulia, Suganda; Wihardjo, Erning; Widjaja, Joewono

2016-11-01

A laser diode device for pre cataract surgery test is proposed. The operation is based on the speckle generated on the retina by the cataract lens, when the cataract lens is illuminated with a coherent laser light.

Mimicking cataract-induced visual dysfunction by means of protein denaturation in egg albumen

NASA Astrophysics Data System (ADS)

Mandracchia, B.; Finizio, A.; Ferraro, P.

2016-03-01

As the world's population ages, cataract-induced visual dysfunction and blindness is on the increase. This is a significant global problem. The most common symptoms of cataracts are glared and blurred vision. Usually, people with cataract have trouble seeing and reading at distance or in low light and also their color perception is altered. Furthermore, cataract is a sneaky disease as it is usually a very slow but progressive process, which creates adaptation so that patients find it difficult to recognize. All this can be very difficult to explain, so we built and tested an optical device to help doctors giving comprehensive answers to the patients' symptoms. This device allows visualizing how cataract impairs vision mimicking the optical degradation of the crystalline related cataracts. This can be a valuable optical tool for medical education as well as to provide a method to illustrate the patients how cataract progression process will affect their vision.

Relationship of cataract symptoms of preoperative patients and vision-related quality of life.

PubMed

Lee, Jae Eun; Fos, Peter J; Sung, Jung Hye; Amy, Brian W; Zuniga, Miguel A; Lee, Won Jae; Kim, Jae Chang

2005-10-01

This study was conducted in an attempt to describe the status of cataract symptoms of preoperative cataract patients, as well as to determine the relationship between cataract symptom and vision-related quality of life measures. A cross-sectional study design was used. Study subjects were selected using non-probabilistic methods. The study sample consisted of 132 patients scheduled for cataract surgery in one eye. Information was obtained from study subjects by conducting face-to-face interviews. Study subjects were adult cataract patients at Samsung and Kunyang General Hospitals in Seoul, Korea, and Tulane University Hospital and Clinics in New Orleans, Louisiana, United States of America. Degree to which study subjects were "bothered" by cataract symptoms was measured by using the 5-item Cataract Symptom Scores (CSS). The number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean of cataract symptom score were created based on the CSS measure. Vision-related quality of life was assessed by using the Visual Function 14 Items (VF-14) and Global Measure of Vision (GMV) for trouble and satisfaction. The symptoms "blurry vision" and "worsening of vision" were most frequently reported. The symptom "colors looking different" was rarely reported among preoperative cataract patients. The degree to which study subjects were bothered by "blurry vision" and "seeing glare, halo, or rings" was highly associated with visual function, visual trouble, and visual satisfaction. Multiple regression analysis revealed that the newly developed cataract symptom-related scales, as well as total amount of degree to which study subjects were "bothered" by symptoms were highly related to vision-related quality of life measures. These relationships were persistent after controlling for major socio-demographic variables. The results indicate that cataract symptoms are highly associated with vision-related quality of life. The results also suggest that the number of symptoms, highest scored symptom among the five, number of symptoms extremely bothering, and the mean cataract symptom scores should be considered an important cataract symptom-related scale when analyzing quality of life, including cataract symptom.

Number of People Blind or Visually Impaired by Cataract Worldwide and in World Regions, 1990 to 2010.

PubMed

Khairallah, Moncef; Kahloun, Rim; Bourne, Rupert; Limburg, Hans; Flaxman, Seth R; Jonas, Jost B; Keeffe, Jill; Leasher, Janet; Naidoo, Kovin; Pesudovs, Konrad; Price, Holly; White, Richard A; Wong, Tien Y; Resnikoff, Serge; Taylor, Hugh R

2015-10-01

To estimate prevalence and number of people visually impaired or blind due to cataract. Based on the Global Burden of Diseases Study 2010 and ongoing literature research, we examined how many people were affected by moderate to severe vision impairment (MSVI; presenting visual acuity <6/18, ≥3/60) and blindness (presenting visual acuity <3/60) due to cataract. In 2010, of overall 32.4 million blind and 191 million vision impaired, 10.8 million people were blind and 35.1 million were visually impaired due to cataract. Cataract caused worldwide 33.4% of all blindness in 2010, and 18.4% of all MSVI. These figures were lower in the high-income regions (<15%) and higher (>40%) in South and Southeast Asia and Oceania. From 1990 to 2010, the number of blind or visually impaired due to cataract decreased by 11.4% and by 20.2%, respectively; the age-standardized global prevalence of cataract-related blindness and MSVI reduced by 46% and 50%, respectively, and the worldwide crude prevalence of cataract-related blindness and MSVI reduced by 32% and 39%, respectively. The percentage of global blindness and MSVI caused by cataract decreased from 38.6% to 33.4%, and from 25.6% to 18.4%, respectively. This decrease took place in almost all world regions, except East Sub-Saharan Africa. In 2010, one in three blind people was blind due to cataract, and one of six visually impaired people was visually impaired due to cataract. Despite major improvements in terms of reduction of prevalence, cataract remains a major public health problem.

Epidemiological correlates of cataract cases in tertiary health care center in rural area of maharashtra.

PubMed

Avachat, Shubhada Sunil; Phalke, Vaishali; Kambale, Suchit

2014-01-01

The most recent estimates from World Health Organization (WHO) reveal that 47.8% of global blindness is due to cataract. Cataract has been documented to be the most significant cause of bilateral blindness in India. The most recent estimates from WHO reveal that 47.8% of global blindness is due to cataract and in south Asia region which includes India, 51% of blindness is due to cataract. In India cataract is the principal cause of blindness accounting for 62.6% cases of blindness. The key to the success of the Global Vision 2020: The right to sight initiative is a special effort to tackle cataract blindness which includes estimation of magnitude of the problem and understanding factors associated with it. Therefore, a study was conducted in the hospital to estimate the magnitude of cataract and study various epidemiological factors associated with it. A cross-sectional study was conducted in a tertiary health center in rural area. Total 746 patients who availed services from ophthalmology department during study period were included in the study and relevant data was collected from them. Data analysis was done by percentages, proportions, and tests of significance (Chi-square test). Out of 746 patients, 400 (53.6%) were suffering from cataract. Senile cataract was the most common cause (54%). Fifty-five percent patients were in the age group of 60-80 years and majority of them were from low socioeconomic strata. The prevalence of cataract in a medical college hospital in rural area was 53.6%. Age, sex, and educational status were significantly associated with cataract.

Nutritional modulation of cataract

USDA-ARS?s Scientific Manuscript database

Cataract, or lens opacification, remains a major cause of blindness worldwide. Cataracts reduce vision in over eighty million people, causing blindness in eighteen million people. The number afflicted by cataract will increase dramatically as the proportion of the elderly global population increase...

Fruit and vegetable intake and vitamins C and E are associated with a reduced prevalence of cataract in a Spanish Mediterranean population

PubMed Central

2013-01-01

Background Cataract is among the major causes of vision impairment and blindness worldwide. Epidemiological studies support the role of antioxidants in the etiology of cataract, but the evidence for one specific antioxidant over another is inconsistent. Few studies have examined the association of cataract with fruit and vegetable intake with inconclusive results. In the present study, the relationship between cataract and fruit and vegetable intake and dietary and blood levels of carotenoids, vitamins C and E were examined in a Spanish Mediterranean population. Methods The present work is an analysis of data from 599 elderly ( ≥ 65 years) participants from the Spanish segment of the EUREYE study. This is a European multi-center cross-sectional population-based study. Cataract was diagnosed using a slit-lamp examination and defined as any lens opacity in either eye or evidence of its removal (cataract extraction). Energy-adjusted intake of fruit and vegetables and antioxidant vitamins was estimated using a semi-quantitative food frequency questionnaire. Plasma concentrations of vitamin C were analyzed by a colorimetric method and carotenoids and α-tocopherol by a HPLC method. The associations between cataract and quartiles of fruit and vegetable intake and plasma antioxidants were investigated using logistic regression models. Results Of the 599 elderly recruited, 433 (73%) had cataract or cataract extraction, 54% were women and 46% were men. After adjustments, increasing quartiles of combined fruit and vegetable intake were associated with decreasing reduction of odds of cataract or cataract extraction, (P for trend = 0.008). Increasing quartiles of dietary intakes from 107 mg/d of vitamin C showed a significant decreasing association with prevalence of cataract or cataract extraction (P for trend = 0.047). For vitamin E, a protective association was found from intakes from 8 mg/d, but no linear trend was observed across quartiles of intake (P for trend = 0.944). Conclusions High daily intakes of fruit and vegetables and vitamins C and E were associated with a significantly decreased of the prevalence of cataract or cataract surgery. This study reinforces the WHO recommendations on the benefits of diets rich in fruit and vegetables. PMID:24106773

Ancestry, Socioeconomic Status, and Age-Related Cataract in Asians: The Singapore Epidemiology of Eye Diseases Study.

PubMed

Chua, Jacqueline; Koh, Jia Yu; Tan, Ava Grace; Zhao, Wanting; Lamoureux, Ecosse; Mitchell, Paul; Wang, Jie Jin; Wong, Tien Yin; Cheng, Ching-Yu

2015-11-01

To determine the prevalence of age-related cataract and its ancestral and socioeconomic risk factors in a multi-ethnic Asian population. Population-based, cross-sectional study. A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years in the Singapore Epidemiology of Eye Diseases Study. Study participants were invited for a structured interview and received a standardized comprehensive eye examination. Digital lens photographs were taken from eyes of each participant and graded for nuclear, cortical, and posterior subcapsular (PSC) cataract, following the Wisconsin Cataract Grading System. Prevalence data were compared with the Blue Mountains Eye Study (BMES) in Australia. Information on medical and lifestyle factors was collected using questionnaires and blood samples. To increase the precision of racial definition, genetic ancestry was derived from genome-wide single nucleotide polymorphism markers using principal component analysis. Regression models were used to investigate the association of cataract with socioeconomic factors (education and income) and genetic ancestry. Age-related cataract. A total of 8750 participants (94.0%) had gradable lens photographs. The age-standardized prevalence of cataract surgery in Chinese (16.0%), Malays (10.6%), and Indians (20.2%) was higher than in white subjects (4.1%). We found the age-standardized cataract prevalence in Chinese (30.4%), Malays (37.8%), and Indians (33.1%) was higher than in whites (18.5%). Cataract was 1.5 to 2 times more common in Asians and began 10 years earlier than in white subjects. Malays had significantly higher age-standardized prevalence of nuclear, cortical, and PSC cataract than Chinese (P<0.001). The severity of nuclear, cortical, and PSC cataract was significantly correlated with genetic ancestry in our South East Asian population. Less education and lower income were associated with cataract for Chinese and Indians but not Malays. The presence of visual impairment associated with cataract was higher in people aged ≥60 years and Malays. We showed that people of different Asian ethnicities had a higher prevalence and earlier age of onset of cataract than Europeans. People of Malay ancestry have a greater severity for all cataract subtypes than people of Chinese ancestry. Education and income were associated with cataract for certain Asian subgroups. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Smoking and its association with cataract: results of the Andhra Pradesh eye disease study from India.

PubMed

Krishnaiah, Sannapaneni; Vilas, Kovai; Shamanna, Bindiganavale R; Rao, Gullapalli N; Thomas, Ravi; Balasubramanian, Dorairajan

2005-01-01

To investigate the associations between tobacco smoking and various forms of cataracts among the people of a state in India. A population-based cross-sectional epidemiologic study was conducted in the south Indian state of Andhra Pradesh (AP). A total of 10,293 subjects of all ages from one urban and three rural areas, representative of the population of AP, were interviewed, and each underwent a detailed dilated ocular evaluation by trained professionals. Data were analyzed for 7416 (72%) of the subjects aged >15 years. Increasing age was significantly associated with all cataract types and history of prior cataract surgery and/or total cataract. In multivariate analyses, after adjusting for all demographic factors and for history of smoking, females, illiterate persons, and those belonging to the extreme lower socioeconomic status group were found to have a significantly higher prevalence of any cataract, adjusted odds ratio (OR)=1.60 (95% confidence interval [CI]: 1.24-1.96), 1.46 (95% CI: 1.17-1.70), and 1.92 (95% CI: 1.14-3.24), respectively. After adjustment, cigarette and cigar smokers had a significantly higher prevalence of any cataract, adjusted OR=1.51 (95% CI: 1.10-2.06) and 1.44 (95% CI: 1.12-1.84), respectively, compared with those who had never smoked ("never-smokers"). A significantly higher prevalence of nuclear, cortical cataract, and history of prior cataract surgery and/ or total cataract was found among cigarette smokers. A dose-response relationship was seen with respect to cigarette and cigar smoking. After adjustment, compared with never-smokers, cigarette smokers who smoked heavily (>14 "pack-years" of smoking) had a significantly higher prevalence of nuclear cataract (OR=1.65; 95% CI: 1.10-2.59), cortical cataract (OR=2.11; 95% CI: 1.38-3.24), and history of prior cataract surgery and/or total cataract (OR=2.10; 95% CI: 1.05-4.22). Nuclear cataract was significantly higher in cigar smokers (adjusted OR=1.55; 95% CI: 1.16-2.01) and in cigar smokers who smoked heavily (>21 person-years of smoking; OR=1.50; 95% CI: 1.10-1.95), compared with never-smokers. Consistent with other studies, tobacco smoking was strongly associated with a higher prevalence of nuclear and cortical cataracts and history of prior cataract surgery in this population. These findings suggest yet another need to educate the community on the importance of cessation of tobacco smoking and perhaps incorporating an antismoking message into school health programs.

Cataract - Multiple Languages

MedlinePlus

... Section Cataract - العربية (Arabic) Bilingual PDF Health Information Translations Chinese, Simplified (Mandarin dialect) (简体中文) Expand Section Cataract - ... Chinese, Simplified (Mandarin dialect)) Bilingual PDF ... Health Information Translations Chinese, Traditional (Cantonese dialect) (繁體中文) Expand Section Cataract - ...

Lenticular abnormalities in children.

PubMed

Khokhar, Sudarshan; Agarwal, Tushar; Kumar, Gaurav; Kushmesh, Rakhi; Tejwani, Lalit Kumar

2012-01-01

To study the lenticular problems in children presenting at an apex institute. Retrospective analysis of records (< 14 years) of new lens clinic cases was done. Of 1,047 children, 687 were males. Mean age at presentation was 6.35 ± 4.13 years. Developmental cataract was seen in 45.6% and posttraumatic cataract in 29.7% of patients. Other abnormalities were cataract with retinal detachment, persistent hyperplastic primary vitreous, subluxated lens, micro/spherophakia, cataract secondary to uveitis, intraocular lens complications, cataract with choroidal coloboma, and visual axis opacification. Developmental and posttraumatic cataracts were the most common abnormalities. Delayed presentation is of concern. Copyright 2012, SLACK Incorporated.

Effects of two antioxidants; α-lipoic acid and fisetin against diabetic cataract in mice.

PubMed

Kan, Emrah; Kiliçkan, Elif; Ayar, Ahmet; Çolak, Ramis

2015-02-01

The purpose of this study was to determine whether α-lipoic acid and fisetin have protective effects against cataract in a streptozotocin-induced experimental cataract model. Twenty-eight male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). Three weeks after induction of diabetes, mice were divided randomly into 4 groups in which each group contained 7 mice; fisetin-treated group (group 1), α-lipoic acid-treated group (group 2), fisetin placebo group (group 3), α-lipoic acid placebo group (group 4). Fisetin and α-lipoic acid were administered intraperitoneally weekly for 5 weeks. Cataract development was assessed at the end of 8 weeks by slit lamp examination, and cataract formation was graded using a scale. All groups developed at least grade 1 cataract formation. In the fisetin-treated group, the cataract stages were significantly lower than in the placebo group (p = 0.02). In the α-lipoic acid-treated group, the cataract stages were lower than in the placebo group but it did not reach to a significant value. Both fisetin and α-lipoic acid had a protective effect on cataract development in a streptozotocin-induced experimental cataract model. The protective effect of fisetin appears as though more effective than α-lipoic acid.

Exome Sequencing of 18 Chinese Families with Congenital Cataracts: A New Sight of the NHS Gene

PubMed Central

Sun, Wenmin; Xiao, Xueshan; Li, Shiqiang; Guo, Xiangming; Zhang, Qingjiong

2014-01-01

Purpose The aim of this study was to investigate the mutation spectrum and frequency of 34 known genes in 18 Chinese families with congenital cataracts. Methods Genomic DNA and clinical data was collected from 18 families with congenital cataracts. Variations in 34 cataract-associated genes were screened by whole exome sequencing and then validated by Sanger sequencing. Results Eleven candidate variants in seven of the 34 genes were detected by exome sequencing and then confirmed by Sanger sequencing, including two variants predicted to be benign and the other pathogenic mutations. The nine mutations were present in 9 of the 18 (50%) families with congenital cataracts. Of the four families with mutations in the X-linked NHS gene, no other abnormalities were recorded except for cataract, in which a pseudo-dominant inheritance form was suggested, as female carriers also had different forms of cataracts. Conclusion This study expands the mutation spectrum and frequency of genes responsible for congenital cataract. Mutation in NHS is a common cause of nonsyndromic congenital cataract with pseudo-autosomal dominant inheritance. Combined with our previous studies, a genetic basis could be identified in 67.6% of families with congenital cataracts in our case series, in which mutations in genes encoding crystallins, genes encoding connexins, and NHS are responsible for 29.4%, 14.7%, and 11.8% of families, respectively. Our results suggest that mutations in NHS are the common cause of congenital cataract, both syndromic and nonsyndromic. PMID:24968223

[Analysis of cataract surgical rate and its influencing factors in Shanghai, China].

PubMed

Zhu, Ming-ming; Zhu, Jian-feng; Zou, Hai-dong; He, Xian-gui; Zhao, Rong; Lu, Li-na

2013-12-17

To explore the cataract surgical rate (CSR) of Shanghai from 2006 to 2012 and examine its influencing factors. As of 2003, a cataract surgery registration form had been filled by physicians after every cataract surgery in Shanghai. The local eye disease prevention team then entered the relevant information into the Shanghai Cataract Operations Database. Based upon this database, CSR of Shanghai was calculated. And the number of cataract surgeries was compared between Shanghai urban and suburban districts as well as among different medical institutions. The overall CSR in Shanghai increased from 1741 in 2006 to 2313 in 2012. In 2012, CSR in urban districts reached 6013 while it stood at 460 and 584 in inner and outer suburb districts respectively. The number of hospitals performing cataract surgery in urban districts was much more than that in suburbs. And the average number of cataract surgeries per hospital per year in suburbs was only one third of that (748 cases) in urban areas. The number of cataract surgeries at in private hospitals increased rapidly during the past 7 years. The number of 1921 cases was nearly twice as many as that at tertiary hospitals in 2012. Phacoemulsification surgery was the most popular surgical choice for cataract removal, accounting for 98.40% of total cataract surgeries in 2012. Until 2012, CSR in Shanghai dropped below the target of World Health Organization (WHO). A low level of CSR in suburbs is a major influencing factor for the overall level of CSR in Shanghai.

Selenite and ebselen supplementation attenuates D-galactose-induced oxidative stress and increases expression of SELR and SEP15 in rat lens.

PubMed

Dai, Jie; Zhou, Jun; Liu, Hongmei; Huang, Kaixun

2016-12-01

Selenite and ebselen supplementation has been shown to possess anti-cataract potential in some experimental animal models of cataract, however, the underlying mechanisms remain unclear. The present study was designed to evaluate the anti-cataract effects and the underlying mechanisms of selenite and ebselen supplementation on galactose induced cataract in rats, a common animal model of sugar cataract. Transmission electron microscopy images of lens fiber cells (LFC) and lens epithelial cells (LEC) were observed in D-galactose-induced experimental cataractous rats treated with or without selenite and ebselen, also redox homeostasis and expression of proteins such as selenoprotein R (SELR), 15kD selenoprotein (SEP15), superoxide dismutase 1 (SOD1), catalase (CAT), β-crystallin protein, aldose reductase (AR) and glucose-regulated protein 78 (GRP78) were estimated in the lenses. The results showed that D-galactose injection injured rat lens and resulted in cataract formation; however, selenite and ebselen supplementation markedly alleviated ultrastructural injury of LFC and LEC. Moreover, selenite and ebselen supplementation could mitigate the oxidative damage in rat lens and increase the protein expressions of SELR, SEP15, SOD1, CAT and β-crystallin, as well as decrease the protein expressions of AR and GRP78. Taken together, these findings for the first time reveal the anti-cataract potential of selenite and ebselen in galactosemic cataract, and provide important new insights into the anti-cataract mechanisms of selenite and ebselen in sugar cataract.

Quantifying changes in lens biomechanical properties due to cold cataract with optical coherence elastography

NASA Astrophysics Data System (ADS)

Zhang, Hongqiu; Wu, Chen; Singh, Manmohan; Larin, Kirill V.

2018-02-01

Cataract is the most prevalent cause of visual impairment worldwide. Cataracts can be formed due to trauma, radiation, drug abuse, or low temperatures. Thus, early detection of cataract can be immensely helpful for preserving visual acuity by ensuring that the appropriate therapeutic procedures are performed at earlier stages of disease onset and progression. In this work, we utilized a phase-sensitive optical coherence elastography (OCE) system to quantify changes in biomechanical properties of porcine lenses in vitro with induced cold cataracts. The results show significant increase in lens Young's modulus due to formation of the cold cataract (from 35 kPa to 60 kPa). These results show that OCE can assess lenticular biomechanical properties and may be useful for detecting and, potentially, characterizing cataracts.

Cataract Blindness in Osun State, Nigeria: Results of a Survey

PubMed Central

Kolawole, Olubayo U.; Ashaye, Adeyinka O.; Mahmoud, Abdulraheem O.; Adeoti, Caroline O.

2012-01-01

Purpose: To estimate the burden of blindness and visual impairment due to cataract in Egbedore Local Government Area of Osun State, Nigeria. Materials and Methods: Twenty clusters of 60 individuals who were 50 years or older were selected by systematic random sampling from the entire community. A total of 1,183 persons were examined. Results: The age- and sex-adjusted prevalence of bilateral cataract-related blindness (visual acuity (VA) < 3/60) in people of 50 years and older was 2.0% (95% confidence interval (CI): 1.6–2.4%). The Cataract Surgical Coverage (CSC) (persons) was 12.1% and Couching Coverage (persons) was 11.8%. The age- and sex-adjusted prevalence of bilateral operable cataract (VA < 6/60) in people of 50 years and older was 2.7% (95% CI: 2.3–3.1%). In this last group, the cataract intervention (surgery + couching) coverage was 22.2%. The proportion of patients who could not attain 6/60 vision after surgery were 12.5, 87.5, and 92.9%, respectively, for patients who underwent intraocular lens (IOL) implantation, cataract surgery without IOL implantation and those who underwent couching. “Lack of awareness” (30.4%), “no need for surgery” (17.6%), cost (14.6%), fear (10.2%), “waiting for cataract to mature” (8.8%), AND “surgical services not available” (5.8%) were reasons why individuals with operable cataract did not undergo cataract surgery. Conclusions: Over 600 operable cataracts exist in this region of Nigeria. There is an urgent need for an effective, affordable, and accessible cataract outreach program. Sustained efforts have to be made to increase the number of IOL surgeries, by making IOL surgery available locally at an affordable cost, if not completely free. PMID:23248537

Prevalence and risk factors for cataract in diabetes: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study, report no. 17.

PubMed

Raman, Rajiv; Pal, Swakshyar Saumya; Adams, James Subrat Kumar; Rani, Padmaja Kumari; Vaitheeswaran, Kulothungan; Sharma, Tarun

2010-12-01

To report the prevalence of cataract and its subtypes in patients with type 2 diabetes mellitus and the risk factors associated with these cataracts. One thousand two hundred eighty-three eligible subjects with type 2 diabetes mellitus, enrolled from a cross-sectional study, underwent examination at the base hospital. Lens opacity was graded by a trained ophthalmologist according to the Lens Opacity Classification System (LOCS) III system. The age- and sex-adjusted prevalence of cataract in the study was 65.7% (95% confidence interval [CI], 65.6-65.8). Mixed cataracts were more common than monotype ones (41.6% vs. 19.4%). The prevalence of cataract was higher in women, subjects with known diabetes and those with longer duration of diabetes (51.4%, 50.3%, and 64.5%, respectively). The risk factors for any type of cataract were increasing age (odds ratio [OR], 1.14; 95% CI, 1.11-1.16), macroalbuminuria (OR, 4.61; 95% CI, 1.56-13.59) and increasing glycosylated hemoglobin (OR, 1.92; 95% CI, 1.22-3.00); higher hemoglobin (OR, 0.38; 95% CI, 0.22-0.64) was the protective factor. The risk factors for nuclear cataract included increasing age (OR, 1.15) and high serum triglycerides (OR, 6.83). For cortical cataract, increasing age (OR, 1.14) and poor glycemic control (OR, 2.43) were the risk factors; increasing hemoglobin (OR, 0.41) was the protective factor. For posterior subcapsular cataract, the risk factors included increasing age (OR, 1.11), being of the female sex (OR, 9.12), employment (OR, 9.80), and duration of diabetes (OR, 21.37). Nearly two thirds of the diabetic population showed evidence of cataract; mixed cataracts were more common than the monotypes ones.

Carbohydrate nutrition, glycemic index, and the 10-y incidence of cataract.

PubMed

Tan, Jennifer; Wang, Jie Jin; Flood, Victoria; Kaushik, Shweta; Barclay, Alan; Brand-Miller, Jennie; Mitchell, Paul

2007-11-01

Although dietary carbohydrates are thought to play a role in cataractogenesis, few epidemiologic studies have examined links between carbohydrate nutrition and cataract. We investigated the associations between dietary glycemic index (GI), glycemic load (GL), total carbohydrate intake, and 10-y incident nuclear, cortical, and posterior subcapsular cataract. Of 3654 baseline participants in an Australian population aged >/=49 y (1992-1994), 933 were seen after 5 and/or 10 y, had completed a detailed semiquantitative food-frequency questionnaire, had no previous cataract surgery or baseline cataract, and had photographs taken to assess incident cataract with the Wisconsin Cataract Grading System. Dietary information was collected with a validated food questionnaire. GI was calculated from a customized database of Australian foods. GI, GL, and all other nutrients were energy adjusted. Hazard ratios (HRs) and 95% CIs were calculated with the use of discrete logistic models. After age, sex, diabetes, and other factors were controlled for, each SD increase in GI significantly predicted incident cortical cataract (HR: 1.19; 95% CI: 1.01, 1.39). Participants within the highest compared with the lowest quartile of GI were more likely to develop incident cortical cataract (HR: 1.77; 95% CI: 1.13, 2.78; P for trend = 0.035). These findings were similar after excluding participants with diabetes, although they were slightly attenuated and marginally nonsignificant (HR: 1.16; 95% CI: 0.98, 1.37, per SD increase in GI). No association was found between GI and nuclear or posterior subcapsular cataract and between GL or carbohydrate quantity and any cataract subtype. In an Australian cohort, poorer dietary carbohydrate quality, reflected by high GI, predicted incident cortical cataract.

Cataract surgical coverage and outcome in the Tibet Autonomous Region of China

PubMed Central

Bassett, K L; Noertjojo, K; Liu, L; Wang, F S; Tenzing, C; Wilkie, A; Santangelo, M; Courtright, P

2005-01-01

Background: A recently published, population based survey of the Tibet Autonomous Region (TAR) of China reported on low vision, blindness, and blinding conditions. This paper presents detailed findings from that survey regarding cataract, including prevalence, cataract surgical coverage, surgical outcome, and barriers to use of services. Methods: The Tibet Eye Care Assessment (TECA) was a prevalence survey of people from randomly selected households from three of the seven provinces of the TAR (Lhoka, Nakchu, and Lingzhr), representing its three main environmental regions. The survey, conducted in 1999 and 2000, assessed visual acuity, cause of vision loss, and eye care services. Results: Among the 15 900 people enumerated, 12 644 were examined (79.6%). Cataract prevalence was 5.2% and 13.8%, for the total population, and those over age 50, respectively. Cataract surgical coverage (vision <6/60) for people age 50 and older (85–90% of cataract blind) was 56% overall, 70% for men and 47% for women. The most common barriers to use of cataract surgical services were distance and cost. In the 216 eyes with cataract surgery, 60% were aphakic and 40% were pseudophakic. Pseudophakic surgery left 19% of eyes blind (<6/60) and an additional 20% of eyes with poor vision (6/24–6/60). Aphakic surgery left 24% of eyes blind and an additional 21% of eyes with poor vision. Even though more women remained blind than men, 28% versus 18% respectively, the different was not statistically significant (p = 0.25). Conclusions: Cataract surgical coverage was remarkably high despite the difficulty of providing services to such an isolated and sparse population. Cataract surgical outcome was poor for both aphakic and pseudophakic surgery. Two main priorities are improving cataract surgical quality and cataract surgical coverage, particularly for women. PMID:15615736

Current status of cataract blindness and Vision 2020: the right to sight initiative in India.

PubMed

Murthy, Gvs; Gupta, Sanjeev K; John, Neena; Vashist, Praveen

2008-01-01

India is a signatory to the World Health Organization resolution on Vision 2020: The right to sight. Efforts of all stakeholders have resulted in increased number of cataract surgeries performed in India, but the impact of these efforts on the elimination of avoidable blindness is unknown. Projection of performance of cataract surgery over the next 15 years to determine whether India is likely to eliminate cataract blindness by 2020. Data from three national level blindness surveys in India over three decades, and projected age-specific population till 2020 from US Census Bureau were used to develop a model to predict the magnitude of cataract blindness and impact of Vision 2020: the right to sight initiatives. Using age-specific data for those aged 50+ years it was observed that prevalence of blindness at different age cohorts (above 50 years) reduced over three decades with a peak in 1989. Projections show that among those aged 50+ years, the quantum of cataract surgery would double (3.38 million in 2001 to 7.63 million in 2020) and cataract surgical rate would increase from 24025/million 50+ in 2001 to 27817/million 50+ in 2020. Though the prevalence of cataract blindness would decrease, the absolute number of cataract blind would increase from 7.75 million in 2001 to 8.25 million in 2020 due to a substantial increase in the population above 50 years in India over this period. Considering existing prevalence and projected incidence of cataract blindness over the period 2001-2020, visual outcomes after cataract surgery and sight restoration rate, elimination of cataract blindness may not be achieved by 2020 in India.

Folic Acid, Vitamin B6, and Vitamin B12 in Combination and Age-Related Cataract in a Randomized Trial of Women.

PubMed

Christen, William G; Glynn, Robert J; Chew, Emily Y; Albert, Christine M; Manson, JoAnn E

2016-01-01

To examine the incidence of cataract and cataract extraction in a trial of folic acid and vitamins B6 and B12. In a randomized, double-masked, placebo-controlled trial, 5442 female health professionals aged 40 years or older with preexisting cardiovascular disease (CVD) or three or more CVD risk factors were randomly assigned to receive a combination of folic acid (2.5 mg/day), vitamin B6 (50 mg/day), and vitamin B12 (1 mg/day), or placebo. A total of 3925 of these women did not have a diagnosis of cataract at baseline and were included in this analysis. The primary endpoint was age-related cataract, defined as an incident age-related lens opacity, responsible for a reduction in best-corrected visual acuity to 20/30 or worse, based on self-report confirmed by medical record review. Extraction of incident age-related cataract was a secondary endpoint of the trial. During an average of 7.3 years of treatment and follow-up, 408 cataracts and 275 cataract extractions were documented. There were 215 cataracts in the combination treatment group and 193 in the placebo group (hazard ratio, HR, 1.10, 95% confidence interval, CI, 0.90-1.33; p = 0.36). For the secondary endpoint of cataract extraction, there were 155 in the combination treatment group and 120 in the placebo group (HR 1.28, 95% CI 1.01-1.63; p = 0.04). In this large-scale randomized trial of women at high risk of CVD, daily supplementation with a combination of folic acid, vitamin B6, and vitamin B12 had no significant effect on cataract, but may have increased the risk of cataract extraction.

Dynamic Light-Scattering Probe Used for the Very Early Detection of Cataracts and to Measure Response to Therapy (or Treatment)

NASA Technical Reports Server (NTRS)

Ansari,Rafat R.; Clark, John I.; King, James F.

2002-01-01

Half of all blindness worldwide is due to cataracts, and 34 million Americans over the age of 65 have cataracts. This figure is expected to rise to 70 million by the year 2030. Currently, no medical treatment is available to prevent or halt the progression of a cataract; nor is there any way to reverse a cataract once it has been detected by conventional methods. The only known treatment is surgical removal of the lens. It is estimated that over $5 billion will be spent this year for the treatment of cataract patients in the United States alone. According to Carl Kupfer, M.D., former Director of the National Eye Institute at the National Institutes of Health, "A delay in cataract formation of about 10 years would reduce the prevalence of visually disabling cataracts by about 45 percent." However, this vision remains a dream because of the lack of objective methods that can be used to detect cataracts very early and, hence, can be used for screening potential anticataract drugs. This is about to change. The National Eye Institute and NASA entered into a formal interagency agreement in late 1996 to develop and test a dynamic light-scattering (DLS) device to detect the earliest changes due to cataract formation. The new DLS probe developed by Dr. Ansari at the NASA Glenn Research Center is several orders of magnitude more sensitive than conventional clinical systems. This ultrahigh sensitivity enables the probe to detect the onset of a cataract before it has any effect on vision and allows researchers to test the effectiveness of anticataract drugs in reversing cataracts. This device (see the following illustration) was originally designed to study transport phenomena in microgravity fluid physics experiments onboard the space shuttle orbiters and space station. It will be very useful in testing anticataract drugs to halt or reverse the progression of cataracts during longitudinal clinical trials.

Cerebral gigantism (Sotos' syndrome) and cataracts.

PubMed

Yeh, H; Price, R L; Lonsdale, D

1978-01-01

A five-year-old girl with cerebral gigantism (Sotos' syndrome) and cataracts is described. Sotos' syndrome, characterized by generalized gigantism with normal endocrine studies has rarely been reported with ocular abnormalities and never with cataracts. It is important to study any child with cataracts for systemic disease.

Etiopathogenesis of cataract: An appraisal

PubMed Central

Gupta, Varun B; Rajagopala, Manjusha; Ravishankar, Basavaiah

2014-01-01

Natural eye lens is a crystalline substance to produce a clear passage for light. Cataract is opacity within the clear lens of the eye and is the dominant cause of socio-medical problem i.e., blindness worldwide. The only available treatment of cataract is surgery. However, insufficient surgical facilities in poor and developing countries and post-operative complications inspire researchers to find out other modes of treatment for cataract. In this review, an attempt has been made to appraise various etiological factors of cataract to make their perception clear to build up counterpart treatment. Present study is an assortment of various available literatures and electronic information in view of cataract etiopathogenesis. Various risk factors have been identified in development of cataracts. They can be classified in to genetic factors, ageing (systemic diseases, nutritional and trace metals deficiencies, smoking, oxidative stress etc.), traumatic, complicated (inflammatory and degenerative diseases of eye), metabolic (diabetes, galactosemia etc.), toxic substances including drugs abuses, alcohol etc., radiation (ultraviolet, electromagnetic waves etc.) are implicated as significant risk factors in the development of cataract. PMID:24618482

The results of ab interno laser thermal sclerostomy combined with cataract surgery versus trabeculectomy combined with cataract surgery 6 to 12 months postoperatively.

PubMed

Kendrick, R; Kollarits, C R; Khan, N

1996-07-01

When cataract surgery and glaucoma surgery are combined, the theoretical advantages of pressure control, removal of the visual impairment, and protection against an increase in intraocular pressure (IOP) in the immediate postoperative period are gained. The authors' objective was to determine whether ab interno laser thermal sclerostomy (LTS) combined with cataract surgery would be as effective as trabeculectomy combined with cataract surgery. Ab interno LTS was compared with trabeculectomy, retrospectively, for patients who had undergone combined cataract and glaucoma surgery. There was no significant difference in the numbers of patients using no medications or fewer medications at 6 and 12 months. There was a greater reduction in IOP in the LTS group. LTS may be better than trabeculectomy in combined cataract and glaucoma surgery because it reduces the IOP more. Compared with trabeculectomy, LTS is simpler to perform and adds less operating time to cataract surgery. Continued follow-up is recommended.

The advanced glaucoma intervention study, 6: effect of cataract on visual field and visual acuity. The AGIS Investigators.

PubMed

2000-12-01

To investigate the effect of cataract on visual function and the role of cataract in explaining a race-treatment interaction in outcomes of glaucoma surgery. The Advanced Glaucoma Intervention Study (AGIS) enrolled 332 black patients (451 eyes) and 249 white patients (325 eyes) with advanced glaucoma. Eyes were randomly assigned to an argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy sequence or a trabeculectomy-ALT-trabeculectomy sequence. From the AGIS experience with cataract surgery during follow-up, we estimated the expected change in visual function scores from before cataract surgery to after cataract surgery. Then, for eyes with cataract not removed, we used these estimates of expected change to adjust visual function scores for the presumed effects of cataract. In turn, we used the adjusted scores to obtain cataract-adjusted main outcome measures. Average percent of eyes with decrease of visual field (APDVF) and average percent of eyes with decrease of visual acuity (APDVA). Within the 2 months before cataract surgery, visual acuity was better in eyes of white patients than of black patients by an average of approximately 2 lines on the visual acuity test chart. Cataract surgery improved visual acuity and visual field defect scores, with the amounts of improvement greater when preoperative visual acuity was lower. Adjustments for cataract brought about the following relative reductions: for APDVF, a relative reduction of 5% to 11% in black patients and 9% to 11% in white patients; for APDVA, a relative reduction of 45% to 49% in black patients and 31% to 38% in white patients; and for the APDVF and APDVA race-treatment interactions, relative reductions of 25% and 45%, respectively. On average, visual function scores improved after cataract surgery. The findings of reduced race-treatment interactions after adjustment for cataract do not alter our earlier conclusion that the AGIS 7-year results support use of the ALT-trabeculectomy-trabeculectomy sequence for black patients and of the trabeculectomy-ALT-trabeculectomy sequence for white patients without life-threatening health problems. The choice of treatment should take into account individual patient characteristics and needs.

Inheritance of congenital cataracts and microphthalmia in the Miniature Schnauzer.

PubMed

Gelatt, K N; Samuelson, D A; Bauer, J E; Das, N D; Wolf, E D; Barrie, K P; Andresen, T L

1983-06-01

Congenital cataracts and microphthalmia in the Miniature Schnauzer were inherited as an autosomal recessive trait. Eighteen matings of affected X affected Miniature Schnauzers resulted in 87 offspring with congenital cataracts and microphthalmia (49 males/38 females). Two matings of congenital cataractous and microphthalmic Miniature Schnauzers (2 females) X a normal Miniature Schnauzer (1 male) yielded 11 clinically normal Miniature Schnauzers (7 males/4 females). Eighteen matings of congenital cataractous and microphthalmic Miniature Schnauzers (6 males) X carrier Miniature Schnauzers (9 females) produced 81 offspring; 39 exhibited congenital cataracts and microphthalmia (20 males/19 females) and 42 had clinically normal eyes (17 males/25 females).

Carbon footprint and cost-effectiveness of cataract surgery.

PubMed

Venkatesh, Rengaraj; van Landingham, Suzanne W; Khodifad, Ashish M; Haripriya, Aravind; Thiel, Cassandra L; Ramulu, Pradeep; Robin, Alan L

2016-01-01

This article raises awareness about the cost-effectiveness and carbon footprint of various cataract surgery techniques, comparing their relative carbon emissions and expenses: manual small-incision cataract surgery (MSICS), phacoemulsification, and femtosecond laser-assisted cataract surgery. As the most commonly performed surgical procedure worldwide, cataract surgery contributes significantly to global climate change. The carbon footprint of a single phacoemulsification cataract surgery is estimated to be comparable to that of a typical person's life for 1 week. Phacoemulsification has been estimated to be between 1.4 and 4.7 times more expensive than MSICS; however, given the lower degree of postoperative astigmatism and other potential complications, phacoemulsification may still be preferable to MSICS in relatively resource-rich settings requiring high levels of visual function. Limited data are currently available regarding the environmental and financial impact of femtosecond laser-assisted cataract surgery; however, in its current form, it appears to be the least cost-effective option. Cataract surgery has a high value to patients. The relative environmental impact and cost of different types of cataract surgery should be considered as this treatment becomes even more broadly available globally and as new technologies are developed and implemented.

Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

PubMed

Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

2016-01-27

A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

Three hundred and three dogs with cataracts seen in Rio de Janeiro, Brazil.

PubMed

Baumworcel, Natasha; Soares, Ana M B; Helms, Gustavo; Rei, Paulo R L; Castro, Maria Cristina N

2009-01-01

To describe the most common canine breeds affected with cataracts in Rio de Janeiro. Three hundred and three dogs were included in this retrospective study. Animal ages ranged from 6 months to 14.8 years. All records of dogs seen by the Ophthalmology Service of Policlínica Veterinária Botafogo between January 2005 and June 2008 were reviewed. Animals with cataracts were separated, and breed and age were evaluated. Most of the dogs presented with cataracts were Toy Poodles with a mean age of 8.2 years, followed by Cocker Spaniels and Bichon Frises. The percentage of Toy Poodles affected with cataracts was 13.8% while 33.3% of Bichon Frise was diagnosed with cataracts. Toy Poodles are a popular breed in Rio de Janeiro. Without regulations on breeding, the prevalence of cataracts may increase rapidly. Furthermore, due to the relatively late onset of cataract formation in the Toy Poodle (mean 8.2 years of age), affected animals may have produced several litters of puppies. This study emphasizes the importance of screening for the presence of inherited ocular abnormalities such as cataracts prior to breeding.

Historical Study of Radiation Exposures and the Incidence of Cataracts in Astronauts

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Manuel, F. K.; Iszard, G.; Feiveson, A.; Peterson, L. E.; Hardy, D.; Marak, L.; Tung, W.; Wear, M.; Chylack, L. T., Jr.

2004-01-01

For over 35 years, astronauts in low Earth orbit or on missions to the moon have been exposed to space radiation comprised of high-energy protons, heavy ions, and secondary neutrons. We reviewed the radiation exposures received by astronauts in space and on Earth, and presented results from the first epidemiological study of cataract incidence in the astronauts. Our data suggested an increased risk for cataracts from space radiation exposures. Using parametric survival analysis and the maximum likelihood method, we estimated the dose-response and age distribution for cataract incidence in astronauts by space radiation. Considering the high-LET dose contributions on specific space missions as well as data from animal studies with neutrons and heavy ions, suggested a linear response with no dose-threshold for cataracts. However, there are unanswered questions related to the importance and the definition of clinically significant cataracts commonly used in radiation protection, especially in light of epidemiological data suggesting that the probability that sub-clinical cataracts will progress is highly dependent on the age at which cataracts appear. We briefly describe a new study that will address the measurement of cataract progression-rates in astronauts and a ground-based comparison group.

Historical Study of Radiation Exposures and the Incidence of Cataracts in Astronauts

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Manuel, F. K.; Iszard, G.; Feiveson, A.; Peterson, L. E.; Hardy, D.; Marak, L.; Tung, W.; Wear, M.; Chylack, L. T., Jr.

2004-01-01

For over 35 years, astronauts in low Earth orbit or on missions to the moon have been exposed to space radiation comprised of high-energy protons, heavy ions, and secondary neutrons. We reviewed the radiation exposures received by astronauts in space and on Earth, and presented results from the first epidemiological study of cataract incidence in the astronauts. Our data suggested an increased risk for cataracts from space radiation exposures*. Using parametric survival analysis and the maximum likelihood method, we estimated the dose-response and age distribution for cataract incidence in astronauts by space radiation. Considering the high-LET dose contributions on specific space missions as well as data from animal studies with neutrons and heavy ions, suggested a linear response with no dose-threshold for cataracts. However, there are unanswered questions related to the importance and the definition of "clinically significant" cataracts commonly used in radiation protection, especially in light of epidemiological data suggesting that the probability that "sub-clinical" cataracts will progress is highly dependent on the age at which cataracts appear. We briefly describe a new study that will address the measurement of cataract progression-rates in astronauts and a ground-based comparison group.

A link between maternal malnutrition and depletion of glutathione in the developing lens: a possible explanation for idiopathic childhood cataract?

PubMed

Kumar, Deepa; Lim, Julie C; Donaldson, Paul J

2013-11-01

Lens cataract is the leading cause of blindness in developing countries. While cataract is primarily a disease of old age and is relatively rare in children, accounting for only four per cent of global blindness, childhood cataract is responsible for a third of the economic cost of blindness. While many of the causes of cataract in children are known, over half of childhood cataracts are idiopathic with no known cause. The incidence of idiopathic cataract is highest in developing countries and studies have discovered that low birth weight is a risk factor in the development of idiopathic childhood cataract. As low birth weight is a reflection of poor foetal growth, it is possible that maternal malnutrition, which is endemic in some developing countries, results in the altered physiology of the foetal lens. We have conducted a review of the literature that provides evidence for a link between maternal malnutrition, low birth weight and the development of childhood cataract. Using our accumulated knowledge on the pathways that deliver nutrients to the adult lens, we propose a cellular mechanism, by which oxidative stress caused by maternal malnutrition affects the development of antioxidant defence pathways in the embryonic lens, leading to an accelerated onset of nuclear cataract in childhood. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

Identification of a novel missense mutation of MAF in a Japanese family with congenital cataract by whole exome sequencing: a clinical report and review of literature.

PubMed

Narumi, Yoko; Nishina, Sachiko; Tokimitsu, Motoharu; Aoki, Yoko; Kosaki, Rika; Wakui, Keiko; Azuma, Noriyuki; Murata, Toshinori; Takada, Fumio; Fukushima, Yoshimitsu; Kosho, Tomoki

2014-05-01

Congenital cataracts are the most important cause of severe visual impairment in infants. Genetic factors contribute to the disease development and 29 genes are known to cause congenital cataracts. Identifying the genetic cause of congenital cataracts can be difficult because of genetic heterogeneity. V-maf avian musculoaponeurotic fibrosarcoma oncogene homolog (MAF) encodes a basic region/leucine zipper transcription factor that plays a key role as a regulator of embryonic lens fiber cell development. MAF mutations have been reported to cause juvenile-onset pulverulent cataract, microcornea, iris coloboma, and other anterior segment dysgenesis. We report on six patients in a family who have congenital cataracts were identified MAF mutation by whole exome sequencing (WES). The heterozygous MAF mutation Q303L detected in the present family occurs in a well conserved glutamine residue at the basic region of the DNA-binding domain. All affected members showed congenital cataracts. Three of the six members showed microcornea and one showed iris coloboma. Congenital cataracts with MAF mutation exhibited phenotypically variable cataracts within the family. Review of the patients with MAF mutations supports the notion that congenital cataracts caused by MAF mutations could be accompanied by microcornea and/or iris coloboma. WES is a useful tool for detecting disease-causing mutations in patients with genetically heterogeneous conditions. © 2014 Wiley Periodicals, Inc.

On Applications of Pyramid Doubly Joint Bilateral Filtering in Dense Disparity Propagation

NASA Astrophysics Data System (ADS)

Abadpour, Arash

2014-06-01

Stereopsis is the basis for numerous tasks in machine vision, robotics, and 3D data acquisition and processing. In order for the subsequent algorithms to function properly, it is important that an affordable method exists that, given a pair of images taken by two cameras, can produce a representation of disparity or depth. This topic has been an active research field since the early days of work on image processing problems and rich literature is available on the topic. Joint bilateral filters have been recently proposed as a more affordable alternative to anisotropic diffusion. This class of image operators utilizes correlation in multiple modalities for purposes such as interpolation and upscaling. In this work, we develop the application of bilateral filtering for converting a large set of sparse disparity measurements into a dense disparity map. This paper develops novel methods for utilizing bilateral filters in joint, pyramid, and doubly joint settings, for purposes including missing value estimation and upscaling. We utilize images of natural and man-made scenes in order to exhibit the possibilities offered through the use of pyramid doubly joint bilateral filtering for stereopsis.

Human Stereopsis is not Limited by the Optics of the Well-focused Eye

PubMed Central

Vlaskamp, Björn N.S.; Yoon, Geunyoung; Banks, Martin S.

2011-01-01

Human stereopsis—the perception of depth from differences in the two eyes’ images—is very precise: Image differences smaller than a single photoreceptor can be converted into a perceived difference in depth. To better understand what determines this precision, we examined how the eyes’ optics affects stereo resolution. We did this by comparing performance with normal, well-focused optics and with optics improved by eliminating chromatic aberration and correcting higher-order aberrations. We first measured luminance contrast sensitivity in both eyes and showed that we had indeed improved optical quality significantly. We then measured stereo resolution in two ways: by finding the finest corrugation in depth that one can perceive, and by finding the smallest disparity one can perceive as different from zero. Our optical manipulation had no effect on stereo performance. We checked this by redoing the experiments at low contrast and again found no effect of improving optical quality. Thus, the resolution of human stereopsis is not limited by the optics of the well-focused eye. We discuss the implications of this remarkable finding. PMID:21734272

Trends in cataract surgical rate and resource utilisation in Egypt.

PubMed

Elbieh, Islam; Bascaran, Covadonga; Blanchet, Karl; Foster, Allen

2018-06-08

To describe cataract services in Egypt and explore resources and practices in public and private sectors. The study was conducted between June and August 2015. All facilities in the country providing cataract services were contacted to obtain information on surgeries performed in 2014. Hospitals performing eye surgery in Quena, Sharkia, and Fayoum regions were visited and a questionnaire on resources for cataract surgery was completed. Cataract surgery was offered in the public sector by 64 government and 16 university teaching hospitals and in the private sector by 101 hospitals. Over 90% of all facilities in the country contacted participated in the study. In 2014, the national cataract surgical rate (CSR) was 3674 varying in governorates from 7579 in Ismailia to 402 in Suez. The private sector performed 70% of cataract surgeries. Analysis of three regions showed an 11.7% increase in cataract output between 2010 and 2014. The average number of cataract surgeries per unit in 2014 was 2272 in private, 1633 in university, and 824 in government hospitals. Private hospitals had 60% of human resources for eye care. Phacoemulsification was the surgical technique in 85.6% of private, 72.1% of university, and 41% of government hospitals. Reasons explaining the differences in output between public and private sectors were the lack of trainers, supervisors, and incentives. The private sector provides most of the cataract services in Egypt, resulting in inadequate services for the poor. There is a 15-fold variation in CSR between the best and least served regions. The public sector could increase cataract output by improving training, supervision, and incentives.

Grading nuclear, cortical and posterior subcapsular cataracts using an objective scatter index measured with a double-pass system.

PubMed

Vilaseca, Meritxell; Romero, Maria José; Arjona, Montserrat; Luque, Sergio Oscar; Ondategui, Juan Carlos; Salvador, Antoni; Güell, José L; Artal, Pablo; Pujol, Jaume

2012-09-01

To evaluate objectively intraocular scattering in eyes with nuclear, cortical and posterior subcapsular cataracts by means of an objective scatter index (OSI) obtained from double-pass images. To compare the results with those obtained using clinical conventional procedures. In this prospective, observational, cross-sectional, non-consecutive case series study, 188 eyes with cataracts of 136 patients were analysed (123 eyes had nuclear, 41 eyes had cortical and 24 eyes had posterior subcapsular cataracts). The control group consisted of 117 eyes of 68 healthy patients. Patient examination included subjective refraction, best spectacle-corrected visual acuity (BSCVA), cataract grade using the lens opacities classification system III (LOCS III) and OSI. We found a decrease in the BSCVA and an increase in the OSI with increasing cataract grade. Statistically significant differences were observed when the OSI of eyes without cataracts and those with different LOCS III were compared. The comparison between the OSI and LOCS III reported good percentages of agreement regarding the number of eyes classified in equivalent levels: 72.4% (nuclear cataracts), 86.6% (cortical cataracts) and 84.3% (posterior subcapsular cataracts). A non-linear regression model was applied between OSI and BSCVA, which resulted in the following multiple correlation coefficients: r=0.878 (nuclear), r=0.843 (cortical) and r=0.844 (posterior subcapsular). The results of the study showed that OSI is a useful parameter for evaluating large amounts of intraocular scattering that can be used, in combination with other conventional procedures, as a valuable tool in clinical practice to grade cataracts objectively.

Mortality after endophthalmitis following contemporary phacoemulsification cataract surgery.

PubMed

Crosby, Niall; Polkinghorne, Philip J; Kim, Bia; McGhee, Charles; Welch, Sarah; Riley, Andrew

2018-04-24

To determine if endophthalmitis following cataract surgery is linked to increased mortality. Increased mortality has been linked to patients with cataract and cataract surgery. We tested the hypothesis that post-cataract endophthalmitis has a greater risk of death than pseudophakes who do not develop this complication. Case-control study conducted in a tertiary public hospital. The study group comprised 50 consecutive patients with post-cataract endophthalmitis, and these were matched with selected controls. Patients with endophthalmitis following cataract surgery were identified from a prospective electronic surgical database. Subsequently, it was determined if the patient was deceased at the time of sequestration (September 2015), and the date of death was recorded. A previously described population who had undergone cataract surgery in the same facility was selected as a control group, and the population was case-matched in terms age, gender, presence or absence of diabetes and/or hypertension. The median survival rates were determined for the control group and the patients with post-cataract endophthalmitis. Fifty patients were identified as undergoing endophthalmitis post-cataract surgery, and 48 (n = 48) met inclusion criteria (mean age 72 years ±12 SD with 30:18 F:M); 17% were diabetic, and 50% had systemic hypertension. No statistically significant difference in median survival between the study and control cases was identified (100 months (95% confidence interval 86-114) vs. 106 months (95% confidence interval 66-146), respectively, P = 0.756). Post-cataract endophthalmitis was not associated with an increased rate of mortality in this study. © 2018 Royal Australian and New Zealand College of Ophthalmologists.

Cataracts in retired actinide-exposed radiation workers.

PubMed

Jacobson, Baruch S

2005-01-01

Radiation-induced cataracts are predominantly of the posterior sub-capsular (PSC) type, whereas about 90% of age-related cataracts are of other types. Retired workers, likely to have transuranic body burdens, from three DOE-supported installations were questioned regarding their eye-care history and asked for permission to contact their eye-care providers regarding any cataracts. In 97 cases with lifetime exposure records 20 cases (20.6%) were reported to have PSC cataracts. However, of 24 individuals with recorded lifetime doses of 200-600 mSv, nine (37.5%) had PSC cataracts, compared with 15.1% of 73 cases with doses of less than 200 mSv. This difference is statistically significant at the 5% level.

Mutations and mechanisms in congenital and age-related cataracts

PubMed Central

Shiels, Alan; Hejtmancik, J. Fielding

2017-01-01

The crystalline lens plays an important role in the refractive vision of vertebrates by facilitating variable fine focusing of light onto the retina. Loss of lens transparency, or cataract, is a frequently acquired cause of visual impairment in adults and may also present during childhood. Genetic studies have identified mutations in over 30 causative genes for congenital or other early-onset forms of cataract as well as several gene variants associated with age-related cataract. However, the pathogenic mechanisms resulting from genetic determinants of cataract are only just beginning to be understood. Here, we briefly summarize current concepts pointing to differences in the molecular mechanisms underlying congenital and age-related forms of cataract. PMID:27334249

Changing trends in barriers to cataract surgery in India.

PubMed

Vaidyanathan, K; Limburg, H; Foster, A; Pandey, R M

1999-01-01

Cataract is a major cause of blindness in Asia. Efforts in India to provide cataract surgical services have had limited success in reaching the cataract-blind population. Earlier studies identified the major barriers to cataract surgery as poverty, lack of transportation or felt need, or sex related; and the critical barriers in rural areas as lack of awareness, difficult access, and cost. Compared with these earlier data, the results of the present study in Karnataka State indicate a shift in the character of the barriers. They now appear to be more related to case selection and service provision. These shifts are analysed and alternative strategies to increase the uptake to cataract surgery are recommended.

[Application of disparity discriminating accuracy test in evaluating the stereopsis of postoperative intermittent exotropia].

PubMed

Feng, L X; Yao, J Y; Chen, L; Tang, Y; Hou, F

2016-08-01

To discuss the application of disparity discriminating accuracy test in evaluating the stereopsis of postoperative intermittent exotropia. Patients with intermittent exotropia who underwent surgery during July 2011 to June 2013 were followed up. The stereoacuity was examined by Titmus Stereotest, Randot Stereotest and Frisby Stereotest. Twenty adult cases whose stereoacuity reached normal were chosen as experimental group. Twenty healthy adults were selected as normal control group. Both groups were examined with disparity discriminating accuracy test. Discriminating accuracy of the two groups were analyzed with Two-Way ANOVA method. Test-retest reliability was analyzed with Intraclass Correlation Coefficient analysis. The test-retest reliability of disparity discriminating accuracy test is excellent (ICC=0.99, P<0.01) . Discriminating accuracy under different disparities in experimental group were 0.56±0.09, 0.67±0.14, 0.77±0.15, 0.82±0.14, 0.85±0.11, 0.85±0.14, 0.87±0.10, 0.84±0.16, while those in control group were 0.77±0.09, 0.88±0.09, 0.93±0.08, 0.91±0.09, 0.95±0.08, 0.96±0.05, 0.97±0.06, 0.96±0.04. There were statistically significant differences between them (F=38.06, P<0.01) . The discriminating ability of group grating in both groups was affected by the size of disparity. Under situation of small disparity, a large difference was found between the experimental group (0.67±0.12)and control group(0.86±0.07) (F=4.84, P<0.05). Stereoscopic function can be evaluated comprehensively with disparity discriminating accuracy test. Use this test, a certain degree of dysfunction in stereopsis can still be found in postoperative intermittent exotropic patients who reached normal stereoacuity examined with traditional stereotests. (Chin J Ophthalmol, 2016, 52: 584-588).

Inherited Congenital Cataract: A Guide to Suspect the Genetic Etiology in the Cataract Genesis

PubMed Central

Messina-Baas, Olga; Cuevas-Covarrubias, Sergio A.

2017-01-01

Cataracts are the principal cause of treatable blindness worldwide. Inherited congenital cataract (CC) shows all types of inheritance patterns in a syndromic and nonsyndromic form. There are more than 100 genes associated with cataract with a predominance of autosomal dominant inheritance. A cataract is defined as an opacity of the lens producing a variation of the refractive index of the lens. This variation derives from modifications in the lens structure resulting in light scattering, frequently a consequence of a significant concentration of high-molecular-weight protein aggregates. The aim of this review is to introduce a guide to identify the gene involved in inherited CC. Due to the manifold clinical and genetic heterogeneity, we discarded the cataract phenotype as a cardinal sign; a 4-group classification with the genes implicated in inherited CC is proposed. We consider that this classification will assist in identifying the probable gene involved in inherited CC. PMID:28611546

Cataract surgery in juvenile xanthogranuloma: case report and a brief review of literature.

PubMed

Muralidhar, R; Jain, Ashish; Vijayalakshmi, P; Suparna, G; Santhi, R; Shetty, Shashikanth

2013-11-01

There is limited literature on the management of cataracts in juvenile xanthogranuloma (JXG). A 2-month-old girl presented to us with hyphema, secondary glaucoma OU and skin nodules suggestive of JXG. She developed bilateral cataracts during her follow-up and was treated successfully with cataract surgery and aphakic rehabilitation.

Objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity

PubMed Central

Zhu, X; Ye, H; He, W; Yang, J; Dai, J; Lu, Y

2017-01-01

Purpose To explore the objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity. Methods We enrolled 130 cataract patients whose best-corrected visual acuity (BCVA) was 20/40 or better preoperatively. Objective visual functions were evaluated with a KR-1W analyzer before and at 1 month after cataract surgery. Results The nuclear (N), cortical (C), and N+C groups had very high preoperative ocular and internal total high-order aberrations (HOAs), coma, and abnormal spherical aberrations. At 1 month after cataract surgery, in addition to the remarkable increase of both uncorrected visual acuity and BCVA, both ocular and internal HOAs in the three groups decreased significantly after cataract surgery (all P<0.05). Point spread function and modulation transfer functions were also improved significantly in these patients (all P<0.05). Conclusions The objective functional vision of patients with 20/40 or better preoperative BCVA improved significantly after cataract surgery. This finding shows that the arbitrary threshold of BCVA worse than 20/40 in China cannot always be used to determine who will benefit from cataract surgery. PMID:27858933

Surgical, medical and developmental outcomes in patients with Down syndrome and cataracts.

PubMed

Santoro, Stephanie L; Atoum, Dema; Hufnagel, Robert B; Motley, William W

2017-01-01

Individuals with Down syndrome have an increased risk for congenital cataracts, but descriptions of surgical, medical and developmental outcomes are sparse. Retrospective review of medical charts of patients with Down syndrome with visits to Cincinnati Children's Hospital from 1988 to 2013 was performed. A case series of five patients with Down syndrome and cataracts is presented. A total of 47 patients with Down syndrome without cataracts were used as a developmental control. Developmental quotients were compared using an independent-sample, unequal variance t-test. Post-operative cataract complication rates ranged from 20% to 60%. Visual outcomes were varied; significant associations between complication rate and visual outcome were not found. Developmental quotients did not show an association with number of complications, but were lower for children with Down syndrome with cataracts requiring surgery compared to children with Down syndrome without cataracts. In children with Down syndrome and congenital cataract, surgical intervention has risk for post-operative complications. Further investigation is needed to determine if there is an association between surgical complications and visual or developmental outcomes.

Automatic Cataract Hardness Classification Ex Vivo by Ultrasound Techniques.

PubMed

Caixinha, Miguel; Santos, Mário; Santos, Jaime

2016-04-01

To demonstrate the feasibility of a new methodology for cataract hardness characterization and automatic classification using ultrasound techniques, different cataract degrees were induced in 210 porcine lenses. A 25-MHz ultrasound transducer was used to obtain acoustical parameters (velocity and attenuation) and backscattering signals. B-Scan and parametric Nakagami images were constructed. Ninety-seven parameters were extracted and subjected to a Principal Component Analysis. Bayes, K-Nearest-Neighbours, Fisher Linear Discriminant and Support Vector Machine (SVM) classifiers were used to automatically classify the different cataract severities. Statistically significant increases with cataract formation were found for velocity, attenuation, mean brightness intensity of the B-Scan images and mean Nakagami m parameter (p < 0.01). The four classifiers showed a good performance for healthy versus cataractous lenses (F-measure ≥ 92.68%), while for initial versus severe cataracts the SVM classifier showed the higher performance (90.62%). The results showed that ultrasound techniques can be used for non-invasive cataract hardness characterization and automatic classification. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Pediatric cataract: challenges and future directions

PubMed Central

Medsinge, Anagha; Nischal, Ken K

2015-01-01

Cataract is a significant cause of visual disability in the pediatric population worldwide and can significantly impact the neurobiological development of a child. Early diagnosis and prompt surgical intervention is critical to prevent irreversible amblyopia. Thorough ocular evaluation, including the onset, duration, and morphology of a cataract, is essential to determine the timing for surgical intervention. Detailed assessment of the general health of the child, preferably in conjunction with a pediatrician, is helpful to rule out any associated systemic condition. Although pediatric cataracts have a diverse etiology, with the majority being idiopathic, genetic counseling and molecular testing should be undertaken with the help of a genetic counselor and/or geneticist in cases of hereditary cataracts. Advancement in surgical techniques and methods of optical rehabilitation has substantially improved the functional and anatomic outcomes of pediatric cataract surgeries in recent years. However, the phenomenon of refractive growth and the process of emmetropization have continued to puzzle pediatric ophthalmologists and highlight the need for future prospective studies. Posterior capsule opacification and secondary glaucoma are still the major postoperative complications necessitating long-term surveillance in children undergoing cataract surgery early in life. Successful management of pediatric cataracts depends on individualized care and experienced teamwork. We reviewed the etiology, preoperative evaluation including biometry, choice of intraocular lens, surgical techniques, and recent developments in the field of childhood cataract. PMID:25609909

Incidence and Characteristics of Cataract Surgery in Poland, during 2010-2015.

PubMed

Nowak, Michał S; Grabska-Liberek, Iwona; Michalska-Małecka, Katarzyna; Grzybowski, Andrzej; Kozioł, Milena; Niemczyk, Wojciech; Więckowska, Barbara; Szaflik, Jacek P

2018-03-02

Background: To assess the incidence and characteristic of cataract surgery in Poland from 2010 to 2015 and to interpret these findings. Patients and methods: Data from all patients who underwent cataract surgery alone or in combined procedures in Poland between January 2010 and December 2015 were evaluated. Patient data were from the national database of hospitalizations maintained by National Health Fund. Data on the population of Poland were obtained from Central Statistical Office of Poland. Results: In total, 1,218,777 cataract extractions (alone or combined with other procedures) were performed in 1,081,345 patients during 2010-2015. Overall, the incidence of cataract surgery increased from 5.22/1000 person-years in 2010 to 6.17/1000 person-years in 2015. Phacoemulsification was performed in 97.46% of cataract extractions, and 3.02% of cataract extractions were combined procedures. The rate of one-day procedures increased from 28.3% in 2010 to 43.1% in 2015. The probability of second-eye surgery 12 months after the first-eye surgery increased from 44% in 2010 to 73% in 2015 (log-rank test p < 0.0001). Conclusion: In Poland, from 2010 to 2015, the total incidence of cataract surgery, the number of people who underwent surgery, and the number of one-day cataract surgeries increased significantly.

Lanosterol reverses protein aggregation in cataracts.

PubMed

Zhao, Ling; Chen, Xiang-Jun; Zhu, Jie; Xi, Yi-Bo; Yang, Xu; Hu, Li-Dan; Ouyang, Hong; Patel, Sherrina H; Jin, Xin; Lin, Danni; Wu, Frances; Flagg, Ken; Cai, Huimin; Li, Gen; Cao, Guiqun; Lin, Ying; Chen, Daniel; Wen, Cindy; Chung, Christopher; Wang, Yandong; Qiu, Austin; Yeh, Emily; Wang, Wenqiu; Hu, Xun; Grob, Seanna; Abagyan, Ruben; Su, Zhiguang; Tjondro, Harry Christianto; Zhao, Xi-Juan; Luo, Hongrong; Hou, Rui; Jefferson, J; Perry, P; Gao, Weiwei; Kozak, Igor; Granet, David; Li, Yingrui; Sun, Xiaodong; Wang, Jun; Zhang, Liangfang; Liu, Yizhi; Yan, Yong-Bin; Zhang, Kang

2015-07-30

The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Lenticular changes in congenital iridolenticular choroidal coloboma.

PubMed

Mohamed, Ashik; Chaurasia, Sunita; Ramappa, Muralidhar; Sangwan, Virender S; Jalali, Subhadra

2014-10-01

To evaluate the lenticular changes associated with congenital iridolenticular choroidal coloboma. Retrospective, observational case series. setting: Tertiary eye care center in south India. study population: Total of 145 eyes of 98 patients. observation procedure: Medical records of all patients with the diagnosis of congenital iridolenticular choroidal coloboma between January 2011 and December 2012 were reviewed retrospectively for demographic profile, extent of coloboma, and associated lenticular changes. Median age of patients at the time of initial visit was 23 years (interquartile range, 13-38 years). The male-to-female ratio was ∼ 1:1. Forty-eight percent had bilateral involvement. Lens showed cataract changes in 68 eyes (48.9%). The most common type of cataract was nuclear sclerosis, which was noted in 51% of cases. A distinct type of cataract, called "coloboma cataract" (characterized by linear opacity in the region of the coloboma), was observed in 29% of cases. Other associated findings were phacodonesis in 3 eyes, dislocation in 3 eyes, and subluxation in 5 eyes. Disc and/or macular involvement in 57 eyes (39.3%) did not influence the type or density of cataract (P > .05). Congenital iridolenticular choroidal coloboma is associated with early cataractous changes. The most common type of cataract is nuclear sclerosis. The type and density of cataract do not seem to be related to the extent of the choroidal coloboma. We suggest a distinct description with the nomenclature "coloboma cataract" to be considered in the clinical grading of cataracts in patients with this condition. Copyright © 2014 Elsevier Inc. All rights reserved.

Plasma catalase activity and malondialdehyde level in patients with cataract.

PubMed

Ateş, N A; Yildirim, O; Tamer, L; Unlü, A; Ercan, B; Muşlu, N; Kanik, A; Hatungil, R; Atik, U

2004-08-01

Oxidative mechanisms play a major role in the aetiology and pathogenesis of cataract, especially in age-related cataract. Our study aims to investigate systemic oxidant and antioxidant markers in cataract patients. The activity of erythrocyte catalase and the level of malondialdehyde in plasma were measured in 40 patients with cataract and 60 healthy control subjects. The malondialdehyde level, as an index of lipid peroxidation, was determined by thiobarbitüric acid reaction according to Yagi. The determination of catalase activity was measured by a method that was defined by Beutler. Catalase enzyme activity and malondialdehyde level were evaluated to find out whether there was a significant difference in these variables. Analysis of variance was used by forming a general linear model that takes age and gender as the covariate. CAT activity was found to be 13 920.2 +/- 847.9 U/l in cataract patients and 16 061.3 +/- 1126.6 U/l in control subjects. CAT activity in cataract patients was significantly lower than the control subjects (P = 0.008). Plasma MDA level is significantly higher in patients with cataract 4.47 +/- 0.35 nmol/ml compared to the control subjects 2.94 +/- 0.26 nmol/ml (P = 0.0001). There was no significant difference between different cataract subgroups when erythrocyte CAT activities and plasma MDA levels were compared (P = 0.322, 0.062). This study shows that oxidant/antioxidant balances alter in the presence of cataract.

Impact of cataract surgery in reducing visual impairment: a review.

PubMed

Khandekar, Rajiv; Sudhan, Anand; Jain, B K; Deshpande, Madan; Dole, Kuldeep; Shah, Mahul; Shah, Shreya

2015-01-01

The aim was to assess the impact of cataract surgeries in reducing visual disabilities and factors influencing it at three institutes of India. A retrospective chart review was performed in 2013. Data of 4 years were collected on gender, age, residence, presenting a vision in each eye, eye that underwent surgery, type of surgery and the amount the patient paid out of pocket for surgery. Visual impairment was categorized as; absolute blindness (no perception of light); blind (<3/60); severe visual impairment (SVI) (<6/60-3/60); moderate visual impairment (6/18-6/60) and; normal vision (≥6/12). Statistically analysis was performed to evaluate the association between visual disabilities and demographics or other possible barriers. The trend of visual impairment over time was also evaluated. We compared the data of 2011 to data available about cataract cases from institutions between 2002 and 2009. There were 108,238 cataract cases (50.6% were female) that underwent cataract surgery at the three institutions. In 2011, 71,615 (66.2%) cases underwent surgery. There were 45,336 (41.9%) with presenting vision < 3/60 and 75,393 (69.7%) had SVI in the fellow eye. Blindness at presentation for cataract surgery was associated to, male patients, Institution 3 (Dristi Netralaya, Dahod) surgeries after 2009, cataract surgeries without Intra ocular lens implant implantation, and patients paying <25 US $ for surgery. Predictors of SVI at time of cataract surgery were, male, Institution 3 (OM), phaco surgeries, those opting to pay 250 US $ for cataract surgeries. Patients with cataract seek eye care in late stages of visual disability. The goal of improving vision related quality of life for cataract patients during the early stages of visual impairment that is common in industrialized countries seems to be non-attainable in the rural India.

Older drivers and cataract: driving habits and crash risk.

PubMed

Owsley, C; Stalvey, B; Wells, J; Sloane, M E

1999-04-01

Cataract is a leading cause of vision impairment in older adults, affecting almost half of those over age 75 years. Driving is a highly visual task and, as with other age groups, older adults rely on the personal automobile for travel. The purpose of this study was to examine the role of cataract in driving. Older adults (aged 55-85 years) with cataract (n = 279) and those without cataract (n = 105) who were legally licensed to drive were recruited from eye clinics to participate in a driving habits interview to assess driving status, exposure, difficulty, and "space" (the distance of driving excursions from home base). Crash data over the prior 5 years were procured from state records. Visual functional tests documented the severity of vision impairment. Compared to those without cataract, older drivers with cataract were approximately two times more likely to report reductions in days driven and number of destinations per week, driving slower than the general traffic flow, and preferring someone else to drive. Those with cataract were five times more likely to have received advice about limiting their driving. Those with cataract were four times more likely to report difficulty with challenging driving situations, and those reporting driving difficulty were two times more likely to reduce their driving exposure. Drivers with cataract were 2.5 times more likely to have a history of at-fault crash involvement in the prior 5 years (adjusted for miles driven/week and days driven/week). These associations remained even after adjustments for the confounding effects of advanced age, impaired general health, mental status deficit, or depression. Older drivers with cataract experience a restriction in their driving mobility and a decrease in their safety on the road. These findings serve as a baseline for our ongoing study evaluating whether improvements in vision following cataract surgery expand driving mobility and improve driver safety.

Awareness and eye health-seeking practices for cataract among urban slum population of Delhi: The North India eye disease awareness study.

PubMed

Misra, Vasundhra; Vashist, Praveen; Singh, Senjam Suraj; Malhotra, Sumit; Gupta, Vivek; Dwivedi, S N; Gupta, Sanjeev K

2017-12-01

The objective of the study was to assess the awareness and health-seeking practices related to cataract in urban slums of Delhi. This study design was a population-based cross-sectional study. Participants aged 18-60 years were recruited from randomly selected five slums of South Delhi. They were interviewed using a semi-structured interview schedule on awareness and eye health-seeking practices related to cataract. The practices were recorded if the respondents themselves or any other member of the family was diagnosed with cataract in previous 2 years. A total of 1552 respondents participated in the study, of which, 89.9% had heard of cataract but only (42%) were aware of any symptom of cataract. The common symptoms of cataract reported by the participants were white opacity in eyes (25.9%) and loss of vision (20.6%). Surgery as a treatment of cataract was known to only 559 (40.1%) participants. Awareness about surgery as treatment of cataract was significantly higher among people aged 45-60 years (adjusted odds ratio = 2.89, 95% confidence interval = 2.11-3.97) and in educated people (adjusted OR = 3.69 95% CI = 2.37-5.73). Out of 84 respondents who had been diagnosed with cataract, the health-seeking practices were observed by 70 (83.3%) participants. Among them, 51 (72.9%) had undergone surgery and another 19 (27.1%) had been advised to wait for surgery. Most of the operated patients 48 (94.1%) attended the postoperative follow-up. The study findings suggest the majority of participants have heard of cataract, but there is low awareness of its symptoms and treatment, and good eye health-seeking practices observed for cataract in urban slum population. Gaps in awareness observed can be filled up by implementing proper eye health education programs.

Evaluation of advanced glycation end-products in diabetic and inherited canine cataracts.

PubMed

Bras, I Dineli; Colitz, Carmen M H; Kusewitt, Donna F; Chandler, Heather; Lu, Ping; Gemensky-Metzler, Anne J; Wilkie, David A

2007-02-01

The receptor for advanced glycation end-products (RAGE) increases in the human cataract and should correlate with increased DNA damage and proliferation of lens epithelial cells (LECs). The purpose of this study was to measure and immunolocalize RAGE in normal and cataractous canine LECs, and to determine whether there was a correlation between RAGE and DNA damage (gadd45), cell-cycle regulation (p21), and LEC proliferation (proliferating cell nuclear antigen, PCNA). Thirty-two anterior lens capsules from 22 dogs that underwent cataract surgery and 10 lenses from dogs with normal eyes were evaluated. Eleven of the cataractous lenses were from diabetic patients (n=16), and eleven were from patients with inherited cataracts (n=16). Standard immunohistochemical staining was performed using antibodies against RAGE, gadd45, p21, PCNA, alpha-smooth muscle actin, and TGF-beta. Immunostaining intensity for each antibody was given a score of 0-4+. Standard Western blot analysis on normal and cataractous lens capsules was performed using the same antibodies as in the immunohistochemical staining. Comparisons were also made based on age and sex. Real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed for RAGE. There was an increase in RAGE expression with age in normal LECs, but no significant difference was seen when normal adult LECs were compared to cataractous LECs. The stage of the cataract and the presence of LIU were not associated with a significant increase in RAGE expression. There was no age-dependent difference in the normal lenses for gadd45, p21, or PCNA. Significant up-regulation of p21 (P < 0.05) and PCNA (P < 0.05) was seen in diabetic cataracts compared to inherited cataracts. RAGE and PCNA expression did not increase with cataractogenesis, possibly due to overexpression associated with normal aging and constant exposure to oxidative stress from sunlight-related ultraviolet irradiation, respectively. However, p21 and PCNA increased in diabetic cataractogenesis suggesting cell cycle and proliferation dysregulation. This may be related to the rapid onset in this type of cataract compared with the more chronic and slower-to-develop inherited cataracts.

Association of Sex With the Global Burden of Cataract.

PubMed

Lou, Lixia; Ye, Xin; Xu, Peifang; Wang, Jingyi; Xu, Yufeng; Jin, Kai; Ye, Juan

2018-02-01

Eye disease burden could help guide health policy making. Differences in cataract burden by sex is a major concern of reducing avoidable blindness caused by cataract. To investigate the association of sex with the global burden of cataract by year, age, and socioeconomic status using disability-adjusted life-years (DALYs). This international, comparative burden-of-disease study extracted the global, regional, and national sex-specific DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataract by year and age from the Global Burden of Disease Study 2015. The DALY data were collected from January 1, 1990, through December 31, 2015, for ever 5 years. The human development index (HDI) in 2015 was extracted as an indicator of national socioeconomic status from the Human Development Report. Comparisons of sex-specific DALY estimates due to cataract by year, age, and socioeconomic status at the global level. Paired Wilcoxon signed rank test, Pearson correlation, and linear regression analyses were performed to evaluate the socioeconomic-associated sex differences in cataract burden. Differences in rates of cataract by sex were similar between 1990 and 2015, with age-standardized DALY rates of 54.5 among men vs 65.0 among women in 1990 and 52.3 among men vs 67.0 among women in 2015. Women had higher rates than men of the same age, and sexual differences increased with age. Paired Wilcoxon signed rank test revealed that age-standardized DALY rates among women were higher than those among men for each HDI-based country group (z range, -4.236 to -6.093; P < .001). The difference (female minus male) in age-standardized DALY rates (r = -0.610 [P < .001]; standardized β = -0.610 [P < .001]) and the female to male age-standardized DALY rate ratios (r = -0.180 [P = .02]; standardized β = -0.180 [P = .02]) were inversely correlated with HDI. Although global cataract health care is progressing, sexual differences in cataract burden showed little improvement in the past few decades. Worldwide, women have a higher cataract burden than men. Older age and lower socioeconomic status are associated with greater differences in rates of cataract by sex. Our findings may enhance public awareness of sexual differences in global cataract burden and emphasize the importance of making sex-sensitive health policy to manage global vision loss caused by cataract.

Changing patterns of cataract services in North-West Nigeria: 2005–2016

PubMed Central

Muhammad, Nasiru; Adamu, Mohammed Dantani; Caleb, Mpyet; Maishanu, Nuhu Mohammed; Jabo, Aliyu Mohammed; Rabiu, Muhammad Mansur; Bascaran, Covadonga; Isiyaku, Sunday

2017-01-01

Purpose This study was conducted to assess the impact of the eye care programme on cataract blindness and cataract surgical services in Sokoto, Nigeria over a 12 year period 2005–2016. Methods Data from the 2005 population based cross-sectional study of blindness in Sokoto state was re-analysed to obtain baseline estimates of the prevalence of cataract blindness and cataract surgical coverage for persons 50 years and over in Wurno health zone. A population based survey of a representative sample of persons 50 years and over in Wurno health zone was conducted in July 2016. Data on eye health workforce, infrastructure and cataract surgical services between 2005 and 2016 were analysed from relevant documents. Results In 2005 the unadjusted prevalence of bilateral cataract blindness (<3/60) in people 50 years and over in Wurno health zone was 5.6% (95% CI: 3.1, 10.1). By 2016 this had fallen to 2.1% (95% CI 1.5%, 2.7%), with the age-sex adjusted prevalence being 1.9% (95% CI 1.3%, 2.5%). The CSC for persons with visual acuity <3/60, <6/60, <6/18 for Wurno health zone was 9.1%, 7.1% and 5.5% respectively in 2005 and this had increased to 67.3%, 62.1% and 34.7% respectively in 2016. The CSR in Sokoto state increased from 272 (1005 operations) in 2006, to 596 (2799 operations) in 2014. In the 2005 survey, couching (a procedure used by traditional practitioners to dislocate the lens into the vitreous cavity) accounted for 87.5% of all cataract interventions, compared to 45.8% in the 2016 survey participants. In 2016 18% of eyes having a cataract operation with IOL implantation had a presenting visual acuity of <6/60 (poor outcome) with the main causes being postoperative complications (53%) and uncorrected refractive error (29%). Conclusion Between 2005 and 2016 there was a doubling in cataract surgical rate, a 7 times increase in cataract surgical coverage (<3/60), and a decrease in cataract blindness and the proportion of eyes being couched. However, there remains a high prevalence of un-operated cataract in 2016 indicating a need to further improve access to affordable and good quality cataract surgical services. PMID:28817733

Association of Cataract Surgery With Mortality in Older Women: Findings from the Women's Health Initiative.

PubMed

Tseng, Victoria L; Chlebowski, Rowan T; Yu, Fei; Cauley, Jane A; Li, Wenjun; Thomas, Fridtjof; Virnig, Beth A; Coleman, Anne L

2018-01-01

Previous studies have suggested an association between cataract surgery and decreased risk for all-cause mortality potentially through a mechanism of improved health status and functional independence, but the association between cataract surgery and cause-specific mortality has not been previously studied and is not well understood. To examine the association between cataract surgery and total and cause-specific mortality in older women with cataract. This prospective cohort study included nationwide data collected from the Women's Health Initiative (WHI) clinical trial and observational study linked with the Medicare claims database. Participants in the present study were 65 years or older with a diagnosis of cataract in the linked Medicare claims database. The WHI data were collected from January 1, 1993, through December 31, 2015. Data were analyzed for the present study from July 1, 2014, through September 1, 2017. Cataract surgery as determined by Medicare claims codes. The outcomes of interest included all-cause mortality and mortality attributed to vascular, cancer, accidental, neurologic, pulmonary, and infectious causes. Mortality rates were compared by cataract surgery status using the log-rank test and Cox proportional hazards regression models adjusting for demographics, systemic and ocular comorbidities, smoking, alcohol use, body mass index, and physical activity. A total of 74 044 women with cataract in the WHI included 41 735 who underwent cataract surgery. Mean (SD) age was 70.5 (4.6) years; the most common ethnicity was white (64 430 [87.0%]), followed by black (5293 [7.1%]) and Hispanic (1723 [2.3%]). The mortality rate was 2.56 per 100 person-years in both groups. In covariate-adjusted Cox models, cataract surgery was associated with lower all-cause mortality (adjusted hazards ratio [AHR], 0.40; 95% CI, 0.39-0.42) as well as lower mortality specific to vascular (AHR, 0.42; 95% CI, 0.39-0.46), cancer (AHR, 0.31; 95% CI, 0.29-0.34), accidental (AHR, 0.44; 95% CI, 0.33-0.58), neurologic (AHR, 0.43; 95% CI, 0.36-0.53), pulmonary (AHR, 0.63; 95% CI, 0.52-0.78), and infectious (AHR, 0.44; 95% CI, 0.36-0.54) diseases. In older women with cataract in the WHI, cataract surgery is associated with lower risk for total and cause-specific mortality, although whether this association is explained by the intervention of cataract surgery is unclear. Further study of the interplay of cataract surgery, systemic disease, and disease-related mortality would be informative for improved patient care.

The Association of Outdoor Activity and Age-Related Cataract in a Rural Population of Taizhou Eye Study: Phase 1 Report

PubMed Central

Ye, Xiaofang; Wang, Xiaofeng; Cai, Lei; Xu, Jianming; Lu, Yi

2015-01-01

Purpose To study the relationship between outdoor activity and risk of age-related cataract (ARC) in a rural population of Taizhou Eye Study (phrase 1 report). Method A population-based, cross-sectional study of 2006 eligible rural adults (≥45 years old) from Taizhou Eye Study was conducted from Jul. to Sep. 2012. Participants underwent detailed ophthalmologic examinations including uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp and fundus examinations as well as questionnaires about previous outdoor activity and sunlight protection methods. ARC was recorded by LOCSⅢ classification system. The prevalence of cortical, nuclear and posterior subcapsular cataract were assessed separately for the risk factors and its association with outdoor activity. Results Of all 2006 eligible participants, 883 (44.0%) adults were diagnosed with ARC. The prevalence rates of cortical, nuclear and posterior subcapsular cataract per person were 41.4%, 30.4% and 1.5%, respectively. Women had a higher tendency of nuclear and cortical cataract than men (OR = 1.559, 95% CI 1.204–2.019 and OR = 1.862, 95% CI 1.456–2.380, respectively). Adults with high myopia had a higher prevalence of nuclear cataract than adults without that (OR = 2.528, 95% CI 1.055–6.062). Multivariable logistic regression revealed that age was risk factor of nuclear (OR = 1.190, 95% CI 1.167–1.213) and cortical (OR = 1.203, 95% CI 1.181–1.226) cataract; eyes with fundus diseases was risk factor of posterior subcapsular cataract (OR = 6.529, 95% CI 2.512–16.970). Outdoor activity was an independent risk factor of cortical cataract (OR = 1.043, 95% CI 1.004–1.083). The risk of cortical cataract increased 4.3% (95% CI 0.4%-8.3%) when outdoor activity time increased every one hour. Furthermore, the risk of cortical cataract increased 1.1% (95% CI 0.1%-2.0%) when cumulative UV-B exposure time increased every one year. Conclusion Outdoor activity was an independent risk factor for cortical cataract, but was not risk factor for nuclear and posterior subcapsular cataract. The risk of cortical cataract increased 4.3% when outdoor activity time increased every one hour. In addition, the risk of cortical cataract increased 1.1% (95% CI 0.1%-2.0%) when cumulative UV-B exposure time increased every one year. PMID:26284359

Neurological and developmental findings in children with cataracts.

PubMed

Pike, M G; Jan, J E; Wong, P K

1989-06-01

Ninety-seven children who were born between 1954 and 1986 and presented to the Visually Impaired Program of British Columbia's Children's Hospital, Vancouver, Canada, with a primary ophthalmologic diagnosis of cataracts, were assessed neurologically, ophthalmologically, audiologically, and developmentally. Causal factors included prenatal infection (35 cases), hereditary cataracts (22 cases), various syndromes and metabolic disorders (9 cases), trauma (1 case), and unknown (30 cases). Ninety children were diagnosed to have congenital cataracts while 7 acquired them. Findings indicated that prenatal infection continues to be a cause of infantile cataracts, despite rubella immunization; that prematurity is not, as has been stated in the past, a cause of infantile cataract; and that careful neurological, audiological, and developmental examination is vital in the assessment of likely causes of this condition.

Depth of Monocular Elements in a Binocular Scene: The Conditions for da Vinci Stereopsis

ERIC Educational Resources Information Center

Cook, Michael; Gillam, Barbara

2004-01-01

Quantitative depth based on binocular resolution of visibility constraints is demonstrated in a novel stereogram representing an object, visible to 1 eye only, and seen through an aperture or camouflaged against a background. The monocular region in the display is attached to the binocular region, so that the stereogram represents an object which…

Image-Aided Navigation Using Cooperative Binocular Stereopsis

DTIC Science & Technology

2014-03-27

Global Postioning System . . . . . . . . . . . . . . . . . . . . . . . . . 1 IMU Inertial Measurement Unit...an intertial measurement unit ( IMU ). This technique capitalizes on an IMU’s ability to capture quick motion and the ability of GPS to constrain long...the sensor-aided IMU framework. Visual sensors provide a number of benefits, such as low cost and weight. These sensors are also able to measure

Myopic refractive shift represents dense nuclear sclerosis and thin lens in lenticular myopia.

PubMed

Cho, Yang Kyung; Huang, Wei; Nishimura, Eiichi

2013-09-01

It is not rare to meet unilateral nuclear sclerotic cataracts with myopic refractive changes (lenticular myopia) compared with the fellow eye in the ophthalmic examination of patients with decreased visual acuity. To determine the relationship between the myopic refractive changes and interocular differences of parameters, we investigated the interocular differences of ocular parameters between a lenticular myopic eye and the fellow eye. This retrospective study included 68 eyes of 34 patients, who showed unilateral lenticular myopia. We compared the dimensions of ocular component, such as anterior chamber depth, anterior chamber volume, lens thickness, vitreous chamber depth, lens position, lens density of nuclear sclerosis, anterior lens curvature and myopic refractive changes (spherical equivalent refraction) between the lenticular myopic eye and the myopic refractive change were examined. Statistically significant differences were found between the lenticular myopic eye and the fellow eye for anterior chamber depth (p = 0.015) anterior chamber volume (p = 0.031), lens thickness (p < 0.001), lens density of the nuclear sclerosis (p < 0.001) and the spherical equivalent myopic refractive changes (p < 0.001). Based on univariate analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of the density of the nuclear sclerosis (r = 0.79, p < 0.001), lens thickness (r = -0.70, p < 0.001) and vitreous chamber depth (r = 0.43, p = 0.012). Based on multiple regression analysis, the interocular difference in spherical equivalent refraction was significantly correlated with interocular differences of density of nuclear sclerosis (p < 0.001) and lens thickness (p = 0.007). The difference in myopic spherical change reflects the differences in the severity of nuclear sclerosis and lens thickness between the lenticular myopic eye and the fellow eye. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

Near infrared radiation damage mechanism in the lens

NASA Astrophysics Data System (ADS)

Söderberg, Per G.; Talebizadeh, Nooshin; Galichanin, Konstantin; Kronschläger, Martin; Schulmeister, Karl; Yu, Zhaohua

2015-03-01

The current data strongly indicates that there is no photochemical effect of in vivo exposure to 1090 nm near IRR radiation within the pupil. Four groups of 20 Sprague-Dawley rats were unilaterally exposed in vivo to 96 W·cm-2 centered inside the pupil for 10, 18, 33 and 60 min, respectively depending on group belonging. This resulted in radiant exposure doses of 57, 103, 198 and 344 kJ·cm-2. Temperature evolution at the limbus during the exposure and difference of intensity of forward light scattering between the exposed and the contralateral not exposed eye was measured at 1 week after exposure. The temperature at the limbus was found to increase exponentially towards an asymptote with an asymptote temperature of around 7 °C and a time constant (1/k) of around 15 s. No increase of light scattering was found despite that the cumulated radiant exposure dose was [80;250] times the threshold for photochemically induced cataract suggested by previous empirical data. It is concluded that at 1090 nm near IRR there is no photochemical effect.

Mouse genetic corneal disease resulting from transgenic insertional mutagenesis

PubMed Central

Ramalho, J S; Gregory-Evans, K; Huxley, C; Seabra, M C

2004-01-01

Background/aims: To report the generation of a new mouse model for a genetically determined corneal abnormality that occurred in transgenesis experiments. Methods: Transgenic mice expressing mutant forms of Rab27a, a GTPase that has been implicated in the pathogenesis of choroideremia, were generated. Results: Only one transgenic line (T27aT15) exhibited an unexpected eye phenotype. T27aT15 mice developed corneal opacities, usually unilateral, and cataracts, resulting in some cases in phthisical eyes. Histologically, the corneal stroma was thickened and vacuolated, and both epithelium and endothelium were thinned. The posterior segment of the eye was also affected with abnormal pigmentation, vessel narrowing, and abnormal leakage of dye upon angiography but was histologically normal. Conclusion: Eye abnormality in T27aT15 mice results from random insertional mutagenesis of the transgene as it was only observed in one line. The corneal lesion observed in T27aT15 mice most closely resembles posterior polymorphous corneal dystrophy and might result from the disruption of the equivalent mouse locus. PMID:14977782

Whole Exome Sequencing in Dominant Cataract Identifies a New Causative Factor, CRYBA2, and a Variety of Novel Alleles in Known Genes

PubMed Central

Reis, Linda M.; Tyler, Rebecca C.; Muheisen, Sanaa; Raggio, Victor; Salviati, Leonardo; Han, Dennis P.; Costakos, Deborah; Yonath, Hagith; Hall, Sarah; Power, Patricia; Semina, Elena V.

2013-01-01

Pediatric cataracts are observed in 1–15 per 10,000 births with 10–25% of cases attributed to genetic causes; autosomal dominant inheritance is the most commonly observed pattern. Since the specific cataract phenotype is not sufficient to predict which gene is mutated, whole exome sequencing (WES) was utilized to concurrently screen all known cataract genes and to examine novel candidate factors for a disease-causing mutation in probands from 23 pedigrees affected with familial dominant cataract. Review of WES data for 36 known cataract genes identified causative mutations in nine pedigrees (39%) in CRYAA, CRYBB1, CRYBB3, CRYGC (2), CRYGD, GJA8 (2), and MIP and an additional likely causative mutation in EYA1; the CRYBB3 mutation represents the first dominant allele in this gene and demonstrates incomplete penetrance. Examination of crystallin genes not yet linked to human disease identified a novel cataract gene, CRYBA2, a member of the βγ-crystallin superfamily. The p.(Val50Met) mutation in CRYBA2 cosegregated with disease phenotype in a four-generation pedigree with autosomal dominant congenital cataracts with incomplete penetrance. Expression studies detected cryba2 transcripts during early lens development in zebrafish, supporting its role in congenital disease. Our data highlight the extreme genetic heterogeneity of dominant cataract as the eleven causative/likely causative mutations affected nine different genes and the majority of mutant alleles were novel. Furthermore, these data suggest that less than half of dominant cataract can be explained by mutations in currently known genes. PMID:23508780

Effect of cataract surgery on retinal nerve fiber layer thickness parameters using scanning laser polarimetry (GDxVCC).

PubMed

Dada, Tanuj; Behera, Geeta; Agarwal, Anand; Kumar, Sanjeev; Sihota, Ramanjit; Panda, Anita

2010-01-01

To study the effect of cataract extraction on the retinal nerve fiber layer (RNFL) thickness, and assessment by scanning laser polarimetry (SLP), with variable corneal compensation (GDx VCC), at the glaucoma service of a tertiary care center in North India. Thirty-two eyes of 32 subjects were enrolled in the study. The subjects underwent RNFL analysis by SLP (GDx VCC) before undergoing phacoemulsification cataract extraction with intraocular lens (IOL) implantation (Acrysof SA 60 AT) four weeks following cataract surgery. The RNFL thickness parameters evaluated both before and after surgery included temporal, superior, nasal, inferior, temporal (TSNIT) average, superior average, inferior average, and nerve fiber index (NFI). The mean age of subjects was 57.6 +/- 11.7 years (18 males, 14 females). Mean TSNIT average thickness (microm) pre- and post-cataract surgery was 49.2 +/- 14.1 and 56.5 +/- 7.6 ( P = 0.001). There was a statistically significant increase in RNFL thickness parameters (TSNIT average, superior average, and inferior average) and decrease in NFI post-cataract surgery as compared to the baseline values. Mean NFI pre- and post-cataract surgery was 41.3 +/- 15.3 and 21.6 +/- 11.8 ( P = 0.001). Measurement of RNFL thickness parameters by scanning laser polarimetry is significantly altered following cataract surgery. Post the cataract surgery, a new baseline needs to be established for assessing the longitudinal follow-up of a glaucoma patient. The presence of cataract may lead to an underestimation of the RNFL thickness, and this should be taken into account when analyzing progression in a glaucoma patient.

Unfolded protein response activation in cataracts.

PubMed

Torres-Bernal, Beatriz E; Torres-Bernal, Luis Fernando; Gutiérrez-Campos, Rafael R; Kershenobich Stalnikowitz, David D; Barba-Gallardo, Luis Fernando; Chayet, Arturo A; Ventura-Juárez, Javier

2014-10-01

To analyze the expression of 78 kDa glucose-regulated protein (GRP78) and activating transcription factor 6 (ATF6), 2 factors in the unfolded protein response (UPR), in age-related and diabetes-associated cataract. Universidad Autónoma de Aguascalientes, Aguascalientes, México. Experimental study. The qualitative and quantitative expression of GRP78 and ATF6 were measured in surgical samples from 11 senile cataracts, 9 diabetic-associated cataracts, and 3 normal lenses. Both proteins were detected by immunofluorescence and immunogold-conjugated antibodies. Quantitative morphometry was used to analyze the differences in GRP78 and ATF6 between samples. The Mann-Whitney test was used for statistical analysis. Scanning electron microscopy showed the characteristic organization of fibers in normal lenses with regular alignment and interdigitation between them. On the other hand, lenses from eyes with senile or diabetic cataract showed the same pattern of misalignment and disorganization of the fibers. Both proteins were detected through immunofluorescence in senile and diabetic cataracts, but not in normal lenses. Immunogold-conjugated antibodies and transmission electron microscopy showed that GRP78 and ATF6 grains were 30% higher and 35% higher, respectively, in diabetic cataracts than in senile cataracts (P<.05). These data show for the first time in humans that GRP78 and ATF6 are present in lens fibers of senile cataracts and diabetic cataracts, establishing that the UPR may be important in the process of cataractogenesis. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Prevalence of pterygium and cataract in indigenous populations of the Brazilian Amazon rain forest.

PubMed

Paula, J S; Thorn, F; Cruz, A A V

2006-05-01

To compare the prevalence of pterygium and cataract in four indigenous populations of the Brazilian Amazonian rain forest (Arawak, Tukano, Maku, and Yanomami) with different ethnic and social behaviour backgrounds. A cross-sectional pterygium and cataract survey was performed in 624 adult Indians of the Brazilian rain forest belonging to four different ethnic groups. The Indians were classified according to their social behaviour in two groups: Arawak and Tukano (group 1) and Maku and Yanomami (group 2). Slit-lamp biomicroscopy was employed to examine the entire sample. All subjects were classified as 1 or 0 according to the presence or absence pterygium and cataract. Sex and age were also recorded. chi(2)-tests revealed that the prevalence of pterygium and cataract differed significantly between groups 1 and 2. For pterygia: 36.6% (97/265) and 5.0% (18/359), respectively (chi(2)=101.2, P<0.0001), and for cataracts: 24.5% (65/265) and 13.7% (49/359) respectively (chi(2)=12.09, P=0.0005). Gender was not associated with pterygium (P=0.1326) and cataract (P=0.2263) in both groups. Elderly subjects showed a significantly higher prevalence of cataract (P<0.0001). The prevalence of pterygia did not increase with age (P=0.8079) in both groups. Indians of group 1 have higher prevalence of pterygia and cataract than Indians of group 2. Social behaviour, especially the rate of sun exposure, appears to be the main factor for the different rates of pterygium and cataract displayed by these indigenous people of the Brazilian rain forest.

The Comparison between Torsional and Conventional Mode Phacoemulsification in Moderate and Hard Cataracts

PubMed Central

Kim, Dong-Hyun; Wee, Won-Ryang; Lee, Jin-Hak

2010-01-01

Purpose To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. Methods Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30. Results Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30. Conclusions Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage. PMID:21165231

The comparison between torsional and conventional mode phacoemulsification in moderate and hard cataracts.

PubMed

Kim, Dong-Hyun; Wee, Won-Ryang; Lee, Jin-Hak; Kim, Mee-Kum

2010-12-01

To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30. Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30. Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage.

Prevalence and vision-related outcomes of cataract surgery in Gujarat, India.

PubMed

Murthy, Gudlavalleti V S; Vashist, Praveen; John, Neena; Pokharel, Gopal; Ellwein, Leon B

2009-01-01

Investigate the prevalence and vision-related outcomes of cataract surgery in an area of high cataract surgical rate. Cluster sampling was used in randomly selecting individuals > or = 50 years of age in 2007. Participants were queried regarding year and place of previous cataract surgery. Cataract surgical procedures and evidence of surgical complications were recorded. The principal cause was identified for eyes presenting with visual acuity (VA) < or = 20/40. A total of 4,738 persons were examined and 834 (17.6%) had cataract surgery. Intra-ocular lenses (IOLs) were used in 84.1% of the 1,299 cataract-operated eyes, with more than half of these having manual small incision surgery. Surgical coverage among the cataract blind (visual acuity [VA] < 20/200) was estimated as 72.2%. Coverage was associated with older age, literacy, and urban residence; gender was not significant. Among cataract-operated eyes, 18.7% presented with VA > or = 20/32 and 18.0% were < 20/200. With best-corrected acuity, the corresponding percentages were 55.7% and 11.0%. Presenting and best-corrected VA > or = 20/63 were associated with young age, literacy, and IOL surgery; urban residence and surgery in non-governmental organizations (NGO)/private facilities were also significant for presenting VA; and recent surgery was significant for best-corrected VA. Refractive error was the main cause of vision impairment/blindness in cataract-operated eyes. Refractive error and posterior capsule opacification, easily treatable causes of visual impairment, are common among the operated. A greater emphasis on the quality of visual acuity outcomes along with sustained efforts to provide access to affordable surgery is needed.

Trends in Medicare Service Volume for Cataract Surgery and the Impact of the Medicare Physician Fee Schedule.

PubMed

Gong, Dan; Jun, Lin; Tsai, James C

2017-08-01

To calculate the associations between Medicare payment and service volume for complex and noncomplex cataract surgeries. The 2005-2009 CMS Part B National Summary Data Files, CMS Part B Carrier Summary Data Files, and the Medicare Physician Fee Schedule. Conducting a retrospective, longitudinal analysis using a fixed-effects model of Medicare Part B carriers representing all 50 states and the District of Columbia from 2005 to 2009, we calculated the Medicare payment-service volume elasticities for noncomplex (CPT 66984) and complex (CPT 66982) cataract surgeries. Service volume data were extracted from the CMS Part B National Summary and Carrier Summary Data Files. Payment data were extracted from the Medicare Physician Fee Schedule. From 2005 to 2009, the proportion of total cataract services billed as complex increased from 3.2 to 6.7 percent. Every 1 percent decrease in Medicare payment was associated with a nonsignificant change in noncomplex cataract service volume (elasticity = 0.15, 95 percent CI [-0.09, 0.38]) but a statistically significant increase in complex cataract service volume (elasticity = -1.12, 95 percent CI [-1.60, -0.63]). Reduced Medicare payment was associated with a significant increase in complex cataract service volume but not in noncomplex cataract service volume, resulting in a shift toward performing a greater proportion of complex cataract surgeries from 2005 to 2009. © Health Research and Educational Trust.

Exploiting ensemble learning for automatic cataract detection and grading.

PubMed

Yang, Ji-Jiang; Li, Jianqiang; Shen, Ruifang; Zeng, Yang; He, Jian; Bi, Jing; Li, Yong; Zhang, Qinyan; Peng, Lihui; Wang, Qing

2016-02-01

Cataract is defined as a lenticular opacity presenting usually with poor visual acuity. It is one of the most common causes of visual impairment worldwide. Early diagnosis demands the expertise of trained healthcare professionals, which may present a barrier to early intervention due to underlying costs. To date, studies reported in the literature utilize a single learning model for retinal image classification in grading cataract severity. We present an ensemble learning based approach as a means to improving diagnostic accuracy. Three independent feature sets, i.e., wavelet-, sketch-, and texture-based features, are extracted from each fundus image. For each feature set, two base learning models, i.e., Support Vector Machine and Back Propagation Neural Network, are built. Then, the ensemble methods, majority voting and stacking, are investigated to combine the multiple base learning models for final fundus image classification. Empirical experiments are conducted for cataract detection (two-class task, i.e., cataract or non-cataractous) and cataract grading (four-class task, i.e., non-cataractous, mild, moderate or severe) tasks. The best performance of the ensemble classifier is 93.2% and 84.5% in terms of the correct classification rates for cataract detection and grading tasks, respectively. The results demonstrate that the ensemble classifier outperforms the single learning model significantly, which also illustrates the effectiveness of the proposed approach. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Relationship between postoperative refractive outcomes and cataract density: multiple regression analysis.

PubMed

Ueda, Tetsuo; Ikeda, Hitoe; Ota, Takeo; Matsuura, Toyoaki; Hara, Yoshiaki

2010-05-01

To evaluate the relationship between cataract density and the deviation from the predicted refraction. Department of Ophthalmology, Nara Medical University, Kashihara, Japan. Axial length (AL) was measured in eyes with mainly nuclear cataract using partial coherence interferometry (IOLMaster). The postoperative AL was measured in pseudophakic mode. The AL difference was calculated by subtracting the postoperative AL from the preoperative AL. Cataract density was measured with the pupil dilated using anterior segment Scheimpflug imaging (EAS-1000). The predicted postoperative refraction was calculated using the SRK/T formula. The subjective refraction 3 months postoperatively was also measured. The mean absolute prediction error (MAE) (mean of absolute difference between predicted postoperative refraction and spherical equivalent of postoperative subjective refraction) was calculated. The relationship between the MAE and cataract density, age, preoperative visual acuity, anterior chamber depth, corneal radius of curvature, and AL difference was evaluated using multiple regression analysis. In the 96 eyes evaluated, the MAE was correlated with cataract density (r = 0.37, P = .001) and the AL difference (r = 0.34, P = .003) but not with the other parameters. The AL difference was correlated with cataract density (r = 0.53, P<.0001). The postoperative refractive outcome was affected by cataract density. This should be taken into consideration in eyes with a higher density cataract. (c) 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

The challenges in improving outcome of cataract surgery in low and middle income countries

PubMed Central

Lindfield, Robert; Vishwanath, Kalluru; Ngounou, Faustin; Khanna, Rohit C

2012-01-01

Cataract is the leading cause of blindness globally and surgery is the only known measure to deal with it effectively. Providing high quality cataract surgical services is critical if patients with cataract are to have their sight restored. A key focus of surgery is the outcome of the procedure. In cataract surgery this is measured predominantly, using visual acuity. Population- and hospital-based studies have revealed that the visual outcome of cataract surgery in many low and middle income settings is frequently sub-optimal, often failing to reach the recommended standards set by the World Health Organization (WHO). Another way of measuring outcome of cataract surgery is to ask patients for their views on whether surgery has changed the functioning of their eyes and their quality of life. There are different tools available to capture patient views and now, these patient-reported outcomes are becoming more widely used. This paper discusses the visual outcome of cataract surgery and frames the outcome of surgery within the context of the surgical service, suggesting that the process and outcome of care cannot be separated. It also discusses the components of patient-reported outcome tools and describes some available tools in more detail. Finally, it describes a hierarchy of challenges that need to be addressed before a high quality cataract surgical service can be achieved. PMID:22944761

Operating Room Performance Improves after Proficiency-Based Virtual Reality Cataract Surgery Training.

PubMed

Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Kjærbo, Hadi; Højgaard-Olsen, Klavs; Subhi, Yousif; Saleh, George M; Park, Yoon Soo; la Cour, Morten; Konge, Lars

2017-04-01

To investigate the effect of virtual reality proficiency-based training on actual cataract surgery performance. The secondary purpose of the study was to define which surgeons benefit from virtual reality training. Multicenter masked clinical trial. Eighteen cataract surgeons with different levels of experience. Cataract surgical training on a virtual reality simulator (EyeSi) until a proficiency-based test was passed. Technical performance in the operating room (OR) assessed by 3 independent, masked raters using a previously validated task-specific assessment tool for cataract surgery (Objective Structured Assessment of Cataract Surgical Skill). Three surgeries before and 3 surgeries after the virtual reality training were video-recorded, anonymized, and presented to the raters in random order. Novices (non-independently operating surgeons) and surgeons having performed fewer than 75 independent cataract surgeries showed significant improvements in the OR-32% and 38%, respectively-after virtual reality training (P = 0.008 and P = 0.018). More experienced cataract surgeons did not benefit from simulator training. The reliability of the assessments was high with a generalizability coefficient of 0.92 and 0.86 before and after the virtual reality training, respectively. Clinically relevant cataract surgical skills can be improved by proficiency-based training on a virtual reality simulator. Novices as well as surgeons with an intermediate level of experience showed improvement in OR performance score. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The risk of cataract in relation to metal arc welding.

PubMed

Slagor, Rebekka Michaelsen; La Cour, Morten; Bonde, Jens Peter

2016-09-01

There are indications that solar ultraviolet radiation (UVR) increases the risk of cataract, but there is only circumstantial evidence that metal welding, an important occupational source of UVR exposure, is a risk factor. The objective of this study is to unravel if metal welding increases the risk of cataract. We compared the risk of being diagnosed with cataract from 1987-2012 in a historic cohort of 4288 male metal arc welders against a reference group comprised of Danish skilled and unskilled male workers with similar age distribution. For the welders' cohort, information on welding was collected from questionnaires and, for both cohorts, information about cataract diagnosis and operation was gathered from Danish national registers. Using Cox regression analysis, the hazard ratio (HR) for cataract diagnosis and/or operation was calculated in the follow-up period adjusted for baseline data regarding age, diabetes, and social group. There were 266 welders and 29 007 referents with a diagnosis and/or operation for cataract. The unadjusted HR for cataract comparing ever-welders with referents was 1.07 [95% confidence interval (95% CI) 0.95-1.21] and the adjusted HR was 1.08 (95% CI 0.95-1.22). Age and diabetes were as expected strong risk factors. We found no increased risk of developing cataract among Danish metal welders who worked with arc welding from 1950-1985. This may be attributed to the effectiveness of personal safety equipment.

Association of vitamin C with the risk of age-related cataract: a meta-analysis.

PubMed

Wei, Lin; Liang, Ge; Cai, Chunmei; Lv, Jin

2016-05-01

Whether vitamin C is a protective factor for age-related cataract remains unclear. Thus, we conducted a meta-analysis to summarize the evidence from epidemiological studies of vitamin C and the risk of age-related cataract. Pertinent studies were identified by searching in PubMed and in Webscience. The random effect model was used to combine the results. Meta-regression and subgroups analyses were used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Egger's regression asymmetry test. Finally, 15 articles with 20 studies for vitamin C intake and eight articles with 10 studies for serum ascorbate were included in this meta-analysis. The relative risk (RR) and 95% confidence interval of cataract for the highest versus the lowest category of vitamin C intake was 0.814 (0.707-0.938), and the associations were significant in America and Asia. Significant association of cataract risk with highest versus the lowest category of serum ascorbate was found in general [0.704 (0.564-0.879)]. Inverse associations were also found between serum ascorbate and nuclear cataract and posterior subcapsular cataract. Higher vitamin C intake and serum ascorbate might be inversely associated with risk of cataract. Vitamin C intake should be advocated for the primary prevention of cataract. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Simultaneous versus Sequential Bilateral Cataract Surgery for Infants with Congenital Cataracts: Visual Outcomes and Economic Costs

PubMed Central

Dave, Hreem; Phoenix, Vidya; Becker, Edmund R.; Lambert, Scott R.

2015-01-01

OBJECTIVES To compare the incidence of adverse events, visual outcomes and economic costs of sequential versus simultaneous bilateral cataract surgery for infants with congenital cataracts. METHODS We retrospectively reviewed the incidence of adverse events, visual outcomes and medical payments associated with simultaneous versus sequential bilateral cataract surgery for infants with congenital cataracts who underwent cataract surgery when 6 months of age or younger at our institution. RESULTS Records were available for 10 children who underwent sequential surgery at a mean age of 49 days for the first eye and 17 children who underwent simultaneous surgery at a mean age of 68 days (p=.25). We found a similar incidence of adverse events between the two treatment groups. Intraoperative or postoperative complications occurred in 14 eyes. The most common postoperative complication was glaucoma. No eyes developed endophthalmitis. The mean absolute interocular difference in logMAR visual acuities between the two treatment groups was 0.47±0.76 for the sequential group and 0.44±0.40 for the simultaneous group (p=.92). Hospital, drugs, supplies and professional payments were on average 21.9% lower per patient in the simultaneous group. CONCLUSIONS Simultaneous bilateral cataract surgery for infants with congenital cataracts was associated with a 21.9% reduction in medical payments and no discernible difference in the incidence of adverse events or visual outcome. PMID:20697007

Factors predisposing to consecutive esotropia after surgery to correct intermittent exotropia.

PubMed

Jang, Jung Hyun; Park, Jung Min; Lee, Soo Jung

2012-10-01

To investigate the incidence of and factors predisposing to consecutive esotropia after intermittent exotropia surgery, and to prevent the onset of consecutive esotropia. We retrospectively surveyed 226 patients who had been followed up for more than 1 year after surgery for intermittent exotropia conducted between February 2005 and September 2010. Consecutive esotropia was defined as an esotropia of at least 10 prism diopters (PD) at distance or near at least once in 2 weeks after surgery. Presumed risk factors for consecutive esotropia were analyzed. Gender, age at surgery, average binocular spherical equivalent, anisometropia, high myopia, amblyopia, preoperative angle of deviation, vertical deviation, A-V pattern strabismus, exotropia type, type of surgery, stereopsis, and suppression were investigated to evaluate factors influencing the onset of consecutive esotropia. Consecutive esotropia occurred in 22 patients (9.7 %). Significant correlations with occurrence of the condition were found with high myopia (P = 0.013), amblyopia (P = 0.047), preoperative angle of deviation of 25-40 PD at distance (P = 0.016), deviation at distance - deviation at near > 10 PD (P = 0.041), lateral incomitance (P = 0.007), tenacious proximal convergence fusion type (P = 0.001), unilateral lateral rectus muscle recession and medial rectus muscle resection (P = 0.001). High myopia, amblyopia, and lateral incomitance were predisposing factors for consecutive esotropia. Furthermore, the preoperative angle of deviation at distance, differences between the angle of deviation at near and at distance, the type of intermittent exotropia, and the type of surgery affected the incidence of consecutive esotropia. More attention must be paid to patients with such factors.

Estrogen Protects Lenses against Cataract Induced by Transforming Growth Factor-β (TGFβ)

PubMed Central

Hales, Angela M.; Chamberlain, Coral G.; Murphy, Christopher R.; McAvoy, John W.

1997-01-01

Cataract, already a major cause of visual impairment and blindness, is likely to become an increasing problem as the world population ages. In a previous study, we showed that transforming growth factor-β (TGFβ) induces rat lenses in culture to develop opacities and other changes that have many features of human subcapsular cataracts. Here we show that estrogen protects against cataract. Lenses from female rats are more resistant to TGFβ-induced cataract than those from males. Furthermore, lenses from ovariectomized females show increased sensitivity to the damaging effects of TGFβ and estrogen replacement in vivo, or exposure to estrogen in vitro, restores resistance. Sex-dependent and estrogen-related differences in susceptibility to cataract formation, consistent with a protective role for estrogen, have been noted in some epidemiological studies. The present study in the rat indicates that estrogen provides protection against cataract by countering the damaging effects of TGFβ. It also adds to an increasing body of evidence that hormone replacement therapy protects postmenopausal women against various diseases. PMID:9016876

Solar ultraviolet radiation cataract.

PubMed

Löfgren, Stefan

2017-03-01

Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

Time-reversed ultrasonically encoded optical focusing through highly scattering ex vivo human cataractous lenses

NASA Astrophysics Data System (ADS)

Liu, Yan; Shen, Yuecheng; Ruan, Haowen; Brodie, Frank L.; Wong, Terence T. W.; Yang, Changhuei; Wang, Lihong V.

2018-01-01

Normal development of the visual system in infants relies on clear images being projected onto the retina, which can be disrupted by lens opacity caused by congenital cataract. This disruption, if uncorrected in early life, results in amblyopia (permanently decreased vision even after removal of the cataract). Doctors are able to prevent amblyopia by removing the cataract during the first several weeks of life, but this surgery risks a host of complications, which can be equally visually disabling. Here, we investigated the feasibility of focusing light noninvasively through highly scattering cataractous lenses to stimulate the retina, thereby preventing amblyopia. This approach would allow the cataractous lens removal surgery to be delayed and hence greatly reduce the risk of complications from early surgery. Employing a wavefront shaping technique named time-reversed ultrasonically encoded optical focusing in reflection mode, we focused 532-nm light through a highly scattering ex vivo adult human cataractous lens. This work demonstrates a potential clinical application of wavefront shaping techniques.

The global burden of cataract.

PubMed

Rao, Gullapalli N; Khanna, Rohit; Payal, Abhishek

2011-01-01

To review the previous year's literature related to prevalence of blindness in general, blindness due to cataract, cataract surgical coverage (CSC) and cataract surgical rates (CSRs). Cataracts are the major cause of blindness and visual impairment in developing countries and contributes to more than 90% of the total disability adjusted life years. This review shows that coverage continues to be a problem in many countries, especially for the female population, those residing in rural areas and those who are illiterate. Although CSR is an indicator of the availability and acceptability of services, for measuring the impact of the program, we should look at combining CSR with CSC. This strategy would also enable us achieve our goal of eliminating avoidable blindness due to cataracts by the year 2020. Cataracts still continue- to be a major cause of blindness globally and with the rapidly aging population, it is a challenge to tackle. We need to plan a comprehensive strategy addressing issues related to availability, affordability, accessibility and acceptability of eye-care services.

Rosmarinic Acid Restores Complete Transparency of Sonicated Human Cataract Ex Vivo and Delays Cataract Formation In Vivo.

PubMed

Chemerovski-Glikman, Marina; Mimouni, Michael; Dagan, Yarden; Haj, Esraa; Vainer, Igor; Allon, Raviv; Blumenthal, Eytan Z; Adler-Abramovich, Lihi; Segal, Daniel; Gazit, Ehud; Zayit-Soudry, Shiri

2018-06-19

Cataract, the leading cause of vision impairment worldwide, arises from abnormal aggregation of crystallin lens proteins. Presently, surgical removal is the only therapeutic approach. Recent findings have triggered renewed interest in development of non-surgical treatment alternatives. However, emerging treatments are yet to achieve full and consistent lens clearance. Here, the first ex vivo assay to screen for drug candidates that reduce human lenticular protein aggregation was developed. This assay allowed the identification of two leading compounds as facilitating the restoration of nearly-complete transparency of phacoemulsified cataractous preparation ex vivo. Mechanistic studies demonstrated that both compounds reduce cataract microparticle size and modify their amyloid-like features. In vivo studies confirmed that the lead compound, rosmarinic acid, delays cataract formation and reduces the severity of lens opacification in model rats. Thus, the ex vivo assay may provide an initial platform for broad screening of potential novel therapeutic agents towards pharmacological treatment of cataract.

Impact of Oncoming Headlight Glare With Cataracts: A Pilot Study

PubMed Central

Hwang, Alex D.; Tuccar-Burak, Merve; Goldstein, Robert; Peli, Eli

2018-01-01

Purpose: Oncoming headlight glare (HLG) reduces the visibility of objects on the road and may affect the safety of nighttime driving. With cataracts, the impact of oncoming HLG is expected to be more severe. We used our custom HLG simulator in a driving simulator to measure the impact of HLG on pedestrian detection by normal vision subjects with simulated mild cataracts and by patients with real cataracts. Methods: Five normal vision subjects drove nighttime scenarios under two HLG conditions (with and without HLG: HLGY and HLGN, respectively), and three vision conditions (with plano lens, simulated mild cataract, and optically blurred clip-on). Mild cataract was simulated by applying a 0.8 Bangerter diffusion foil to clip-on plano lenses. The visual acuity with the optically blurred lenses was individually chosen to match the visual acuity with the simulated cataract clip-ons under HLGN. Each nighttime driving scenario contains 24 pedestrian encounters, encompassing four pedestrian types; walking along the left side of the road, walking along the right side of the road, crossing the road from left to right, and crossing the road from right to left. Pedestrian detection performances of five patients with mild real cataracts were measured using the same setup. The cataract patients were tested only in HLGY and HLGN conditions. Participants’ visual acuity and contrast sensitivity were also measured in the simulator with and without stationary HLG. Results: For normal vision subjects, both the presence of oncoming HLG and wearing the simulated cataract clip-on reduced pedestrian detection performance. The subjects performed worst in events where the pedestrian crossed from the left, followed by events where the pedestrian crossed from the right. Significant interactions between HLG condition and other factors were also found: (1) the impact of oncoming HLG with the simulated cataract clip-on was larger than with the plano lens clip-on, (2) the impact of oncoming HLG was larger with the optically blurred clip-on than with the plano lens clip-on, but smaller than with the simulated cataract clip-on, and (3) the impact was larger for the pedestrians that crossed from the left than those that crossed from the right, and for the pedestrians walking along the left side of the road than walking along the right side of the road, suggesting that the pedestrian proximity to the glare source contributed to the performance reduction. Under HLGN, almost no pedestrians were missed with the plano lens or the simulated cataract clip-on (0 and 0.5%, respectively), but under HLGY, the rate of pedestrian misses increased to 0.5 and 6%, respectively. With the optically blurred clip-on, the percent of missed pedestrians under HLGN and HLGY did not change much (5% and 6%, respectively). Untimely response rate increased under HLGY with the plano lens and simulated cataract clip-ons, but the increase with the simulated cataract clip-on was significantly larger than with the plano lens clip-on. The contrast sensitivity with the simulated cataract clip-on was significantly degraded under HLGY. The visual acuity with the plano lens clip-on was significantly improved under HLGY, possibly due to pupil myosis. The impact of HLG measured for real cataract patients was similar to the impact on performance of normal vision subjects with simulated cataract clip-ons. Conclusion: Even with mild (simulated or real) cataracts, a substantial negative effect of oncoming HLG was measurable in the detection of crossing and walking-along pedestrians. The lowered pedestrian detection rates and longer response times with HLGY demonstrate a possible risk that oncoming HLG poses to patients driving with cataracts. PMID:29559933

Topical Anesthesia for Cataract Surgery: The Patients' Perspective

PubMed Central

Apil, Aytekin; Ekinci, Metin; Cagatay, Halil Huseyin; Keles, Sadullah; Ceylan, Erdinc; Cakici, Ozgur

2014-01-01

Purpose. To evaluate the analgesic efficacy of 0.5% propacaine hydrochloride as topical anesthesia during phacoemulsification surgery. Methods. Intraoperative pain intensity was assessed using a 5-category verbal rating scale during each of three surgical stages. Pain scores from each surgical stage and total pain scores were compared for the factors of patient age, gender, cataract laterality, and type. Results. In comparison of cataract type subgroups, the mean total pain scores and mean stage 2 pain scores in both white mature cataract (WMC) and corticonuclear plus posterior subcapsular cataract (CN + PSC) groups were significantly higher than in the PSC-only (PSC) group (P < 0.05). Conclusion. Phacoemulsification with topical anesthesia is not a completely painless procedure. Pain intensity varies with cataract type and stage of surgery. PMID:25050180

Cataract, visual impairment and long-term mortality in a rural cohort in India: the Andhra Pradesh Eye Disease Study.

PubMed

Khanna, Rohit C; Murthy, Gudlavalleti V S; Giridhar, Pyda; Krishnaiah, Sannapaneni; Pant, Hira B; Palamaner Subash Shantha, Ghanshyam; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N

2013-01-01

A large-scale prevalence survey of blindness and visual impairment (The Andhra Pradesh Eye Diseases Study [APEDS1]) was conducted between 1996-2000 on 10,293 individuals of all ages in three rural and one urban clusters in Andhra Pradesh, Southern India. More than a decade later (June 2009-March 2010), APEDS1 participants in rural clusters were traced (termed APEDS2) to determine ocular risk factors for mortality in this longitudinal cohort. Mortality hazard ratio (HR) analysis was performed for those aged >30 years at APEDS1, using Cox proportional hazard regression models to identify associations between ocular exposures and risk of mortality. Blindness and visual impairment (VI) were defined using Indian definitions. 799/4,188 (19.1%) participants had died and 308 (7.3%) had migrated. Mortality was higher in males than females (p<0.001). In multivariable analysis, after adjusting for age, gender, diabetes, hypertension, body mass index, smoking and education status the mortality HR was 1.9 (95% CI: 1.5-2.5) for blindness; 1.4 (95% CI: 1.2-1.7) for VI; 1.8 (95% CI: 1.4-2.3) for pure nuclear cataract, 1.5 (95% CI: 1.1-2.1) for pure cortical cataract; 1.96 (95% CI: 1.6-2.4) for mixed cataract, 2.0 (95% CI: 1.4-2.9) for history of cataract surgery, and 1.58 (95% CI: 1.3-1.9) for any cataract. When all these factors were included in the model, the HRs were attenuated, being 1.5 (95% CI: 1.1-2.0) for blindness and 1.2 (95% CI: 0.9-1.5) for VI. For lens type, the HRs were as follows: pure nuclear cataract, 1.6 (95% CI: 1.3-2.1); pure cortical cataract, 1.5 (95% CI: 1.1-2.1); mixed cataract, 1.8 (95% CI: 1.4-2.2), and history of previous cataract surgery, 1.8 (95% CI: 1.3-2.6). All types of cataract, history of cataract surgery and VI had an increased risk of mortality that further suggests that these could be potential markers of ageing.

Prevention and reversal of selenite-induced cataracts by N-acetylcysteine amide in Wistar rats.

PubMed

Maddirala, Yasaswi; Tobwala, Shakila; Karacal, Humeyra; Ercal, Nuran

2017-04-26

The present study sought to evaluate the efficacy of N-acetylcysteine amide (NACA) eye drops in reversing the cataract formation induced by sodium selenite in male Wistar rat pups. Forty male Wistar rat pups were randomly divided into a control group, an N-acetylcysteine amide-only group, a sodium selenite-induced cataract group, and a NACA-treated sodium selenite-induced cataract group. Sodium selenite was injected intraperitoneally on postpartum day 10, whereas N-acetylcysteine amide was injected intraperitoneally on postpartum days 9, 11, and 13 in the respective groups. Cataracts were evaluated at the end of week 2 (postpartum day 14) when the rat pups opened their eyes. N-acetylcysteine amide eye drops were administered beginning on week 3 until the end of week 4 (postpartum days 15 to 30), and the rats were sacrificed at the end of week 4. Lenses were isolated and examined for oxidative stress parameters such as glutathione, lipid peroxidation, and calcium levels along with the glutathione reductase and thioltransferase enzyme activities. Casein zymography and Western blot of m-calpain were performed using the water soluble fraction of lens proteins. Morphological examination of the lenses in the NACA-treated group indicated that NACA was able to reverse the cataract grade. In addition, glutathione level, thioltransferase activity, m-calpain activity, and m-calpain level (as assessed by Western blot) were all significantly higher in the NACA-treated group than in the sodium selenite-induced cataract group. Furthermore, sodium selenite- injected rat pups had significantly higher levels of malondialdehyde, glutathione reductase enzyme activity, and calcium levels, which were reduced to control levels upon treatment with NACA. The data suggest that NACA has the potential to significantly improve vision and decrease the burden of cataract-related loss of function. Prevention and reversal of cataract formation could have a global impact. Development of pharmacological agents like NACA may eventually prevent cataract formation in high-risk populations and may prevent progression of early-stage cataracts. This brings a paradigm shift from expensive surgical treatment of cataracts to relatively inexpensive prevention of vision loss.

Long-term physical activity and risk of age-related cataract: a population-based prospective study of male and female cohorts.

PubMed

Zheng Selin, Jinjin; Orsini, Nicola; Ejdervik Lindblad, Birgitta; Wolk, Alicja

2015-02-01

To examine the association of total and specific types of physical activity, including walking or bicycling, exercising, work or occupational activity, home or housework, and leisure time inactivity with the risk of age-related cataract in women and men. Population-based prospective cohort study. A total of 52 660 participants (23 853 women and 28 807 men) 45 to 83 years of age from the Swedish Mammography Cohort and the Cohort of Swedish Men. Physical activity was assessed using a self-administered questionnaire at baseline. Cataract diagnosis and extraction were identified through linkage to registers. Incident age-related cataract diagnosis and cataract extraction. During a mean 12.1 years of follow-up (between January 1, 1998, and December 31, 2011; 634 631 person-years), 11 580 incident age-related cataract cases were identified. After adjusting for potential confounders, the highest quartile of total physical activity was statistically significantly associated with 13% decreased risk of cataract compared with the lowest (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.82-0.92). Walking or bicycling (>60 minutes/day vs. hardly ever; HR, 0.88; 95% CI, 0.82-0.95) and work or occupational activity (heavy manual labor vs. mostly sitting; HR, 0.84; 95% CI, 0.78-0.91) also were associated with decreased risk of cataract. Exercise training and home or housework were not associated with cataract risk. Leisure time inactivity was associated with increased risk of cataract (>6 vs. <1 hours/day; HR, 1.27; 95% CI, 1.07-1.50). The HR for high long-term total physical activity compared with low levels both at 30 years of age and at baseline was 0.76 (95% CI, 0.69-0.85). Our findings indicate that high total physical activity, especially in the long term, and such specific types of physical activity as walking or bicycling and work or occupational activity, may be associated with decreased risk of age-related cataract. Conversely, high inactivity levels may be associated with increased risk of cataract. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Global prevalence and economic and humanistic burden of astigmatism in cataract patients: a systematic literature review.

PubMed

Anderson, David F; Dhariwal, Mukesh; Bouchet, Christine; Keith, Michael S

2018-01-01

To systematically review the published evidence on the prevalence and economic and humanistic burden of astigmatism in cataract patients. For this systematic literature review, the Medline, PubMed, Embase, and Cochrane databases were searched from 1996 to September 2015 for available scientific literature that met the inclusion criteria. Studies published in the English language reporting prevalence and humanistic and economic burden in patients diagnosed with cataract and astigmatism were included. Of 3,649 papers reviewed, 31 studies from 32 publications met the inclusion criteria of this review. Preexisting astigmatism ≥1 D was present in up to 47% of cataract eyes. The cost burden of residual uncorrected astigmatism after cataract surgery was driven by the cost of spectacles, which was estimated to range from $2,151 to $3,440 in the US and $1,786 to $4,629 in Europe over a lifetime. In cataract patients, both preexisting and postoperative residual astigmatism were associated with poor vision-related patient satisfaction and quality of life, as well as higher spectacle burden. Astigmatism correction during cataract surgery appears to improve visual outcomes and results in overall lifetime cost savings compared to astigmatism correction with postoperative vision correction. There is a high prevalence of preexisting astigmatism in cataract patients. Although published data are limited, both preoperative astigmatism and postoperative residual astigmatism affect visual function and vision-related quality of life, resulting in increased humanistic burden. Suboptimal correction of astigmatism during cataract surgery drives the continuous need for vision correction with spectacles in the postoperative period. Patients must bear the out-of-pocket expenses, since payers often do not reimburse the cost of spectacles. Greater access to astigmatism correction during cataract surgery could improve visual outcomes and quality of life in patients. More research is required to gain a better understanding of the disease burden of astigmatism in cataract patients.

Global prevalence and economic and humanistic burden of astigmatism in cataract patients: a systematic literature review

PubMed Central

Anderson, David F; Dhariwal, Mukesh; Bouchet, Christine; Keith, Michael S

2018-01-01

Purpose To systematically review the published evidence on the prevalence and economic and humanistic burden of astigmatism in cataract patients. Materials and methods For this systematic literature review, the Medline, PubMed, Embase, and Cochrane databases were searched from 1996 to September 2015 for available scientific literature that met the inclusion criteria. Studies published in the English language reporting prevalence and humanistic and economic burden in patients diagnosed with cataract and astigmatism were included. Results Of 3,649 papers reviewed, 31 studies from 32 publications met the inclusion criteria of this review. Preexisting astigmatism ≥1 D was present in up to 47% of cataract eyes. The cost burden of residual uncorrected astigmatism after cataract surgery was driven by the cost of spectacles, which was estimated to range from $2,151 to $3,440 in the US and $1,786 to $4,629 in Europe over a lifetime. In cataract patients, both preexisting and postoperative residual astigmatism were associated with poor vision-related patient satisfaction and quality of life, as well as higher spectacle burden. Astigmatism correction during cataract surgery appears to improve visual outcomes and results in overall lifetime cost savings compared to astigmatism correction with postoperative vision correction. Conclusion There is a high prevalence of preexisting astigmatism in cataract patients. Although published data are limited, both preoperative astigmatism and postoperative residual astigmatism affect visual function and vision-related quality of life, resulting in increased humanistic burden. Suboptimal correction of astigmatism during cataract surgery drives the continuous need for vision correction with spectacles in the postoperative period. Patients must bear the out-of-pocket expenses, since payers often do not reimburse the cost of spectacles. Greater access to astigmatism correction during cataract surgery could improve visual outcomes and quality of life in patients. More research is required to gain a better understanding of the disease burden of astigmatism in cataract patients. PMID:29563768

Protective effects of ebselen on sodium-selenite-induced experimental cataract in rats.

PubMed

Aydemir, Orhan; Güler, Mete; Kaya, Mehmet Kaan; Deniz, Nurettin; Üstündağ, Bilal

2012-12-01

To determine whether ebselen has a protective effect or antioxidative potential in a sodium-selenite-induced experimental cataract model. Fırat University, Elazığ, Turkey. Experimental study. Twenty-one Sprague-Dawley rat pups were randomly divided into a control group, a sodium-selenite-induced-cataract group, and an ebselen-treated group; each group contained 7 rat pups. Rats in the control group received dimethyl sulfoxide (DMSO) intraperitoneally only and rats in the sodium-selenite-induced-cataract group received 30 nmol/g body weight sodium selenite subcutaneously and DMSO intraperitoneally 10 days postpartum. Rats in the ebselen group received 30 nmol/g body weight sodium selenite subcutaneously 10 days postpartum and were treated with 5 mg/kg body weight ebselen once a day for 4 consecutive days. Cataract development was assessed weekly for 3 weeks by slitlamp examination and graded using a scale. Reduced glutathione (GSH), total nitrite, and malondialdehyde (MDA) levels in lens supernatants were measured at the end of 3 weeks. In the control group, all lenses were clear. In the ebselen-treated group, the mean cataract stage was significantly lower than in the sodium-selenite-induced-cataract group (P = .022). The GSH levels were significantly lower in the sodium-selenite-induced-cataract group than in the control and ebselen groups (P < .001). The MDA levels were lower in the ebselen group than in the sodium-selenite-induced-cataract group (P < .001). The mean total nitrite level was significantly lower in the sodium-selenite-induced-cataract group than in the ebselen group (P = .001). Ebselen had a protective effect on cataract development in a sodium-selenite-induced experimental model. The protective effect of ebselen appears to be due to inhibition of oxidative stress. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study

PubMed Central

Ravilla, Thulasiraj D.; Gupta, Sanjeev; Ravindran, Ravilla D.; Vashist, Praveen; Krishnan, Tiruvengada; Maraini, Giovanni; Chakravarthy, Usha; Fletcher, Astrid E.

2016-01-01

Background: Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. Objectives: To examine the association of biomass cooking fuels with cataract and type of cataract. Methods: We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution. Results: Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men. Conclusions: Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857–1862; http://dx.doi.org/10.1289/EHP193 PMID:27227523

Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study.

PubMed

Ravilla, Thulasiraj D; Gupta, Sanjeev; Ravindran, Ravilla D; Vashist, Praveen; Krishnan, Tiruvengada; Maraini, Giovanni; Chakravarthy, Usha; Fletcher, Astrid E

2016-12-01

Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. To examine the association of biomass cooking fuels with cataract and type of cataract. We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution. Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men. Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857-1862; http://dx.doi.org/10.1289/EHP193.

Recognizing Cataracts

MedlinePlus

... age-related cataract. They recommend eating plenty of green leafy vegetables, fruits, nuts and other healthy foods. Also, don’t smoke, because smoking may speed cataract development. To screen for early signs of eye disease, Bishop recommends ...

Effect of cataract surgery on retinal nerve fiber layer thickness parameters using scanning laser polarimetry (GDxVCC)

PubMed Central

Dada, Tanuj; Behera, Geeta; Agarwal, Anand; Kumar, Sanjeev; Sihota, Ramanjit; Panda, Anita

2010-01-01

Purpose: To study the effect of cataract extraction on the retinal nerve fiber layer (RNFL) thickness, and assessment by scanning laser polarimetry (SLP), with variable corneal compensation (GDx VCC), at the glaucoma service of a tertiary care center in North India. Materials and Methods: Thirty-two eyes of 32 subjects were enrolled in the study. The subjects underwent RNFL analysis by SLP (GDx VCC) before undergoing phacoemulsification cataract extraction with intraocular lens (IOL) implantation (Acrysof SA 60 AT) four weeks following cataract surgery. The RNFL thickness parameters evaluated both before and after surgery included temporal, superior, nasal, inferior, temporal (TSNIT) average, superior average, inferior average, and nerve fiber index (NFI). Results: The mean age of subjects was 57.6 ± 11.7 years (18 males, 14 females). Mean TSNIT average thickness (μm) pre- and post-cataract surgery was 49.2 ± 14.1 and 56.5 ± 7.6 (P = 0.001). There was a statistically significant increase in RNFL thickness parameters (TSNIT average, superior average, and inferior average) and decrease in NFI post-cataract surgery as compared to the baseline values. Mean NFI pre- and post-cataract surgery was 41.3 ± 15.3 and 21.6 ± 11.8 (P = 0.001). Conclusions: Measurement of RNFL thickness parameters by scanning laser polarimetry is significantly altered following cataract surgery. Post the cataract surgery, a new baseline needs to be established for assessing the longitudinal follow-up of a glaucoma patient. The presence of cataract may lead to an underestimation of the RNFL thickness, and this should be taken into account when analyzing progression in a glaucoma patient. PMID:20689193

Risk of occupational radiation-induced cataract in medical workers.

PubMed

Milacic, Snezana

2009-01-01

ionizing radiation on the lens of the eye can produce a progressive cataract. Small cumulative doses, over a long time period, can produce adverse effects on the professional capabilities of health workers in the ionizing radiation zone. The aim of this study was to ascertain whether occupational exposure to low levels of ionizing radiation can cause an increase in prevalence of cataract. We compared a group with occupational cataract, consisting of 115 health workers in the ionizing radiation zone, and two control groups: a group of 100 health-care workers in the ionizing radiation zone, with a higher incidence of chromosomal aberrations, but without cataract; and another control group of 26 health-care workers with cataract, outside the zone; all risk factors for the development of cataract were considered: age, sex, diference in profession, duration of occupational exposure, years of service, level of blood sugar, blood pressure, arrhythmias, etc. A more significant incidence of cataract was found in workers in the ionizing radiation zone, where the relative risk was 4.6; p < 0.01. Radiology technicians showed the highest prevalence (63.5%), while physicians-radiologists and pneumologists were second (15.7%) and third (10.3%) respectively; nurses showed a 3.5% incidence and nuclear medicine department workers showed an incidence of only 1.7%. Other risk factors had an effect on the development of cataract (p < 0.05). Occupational exposure to low doses of ionizing radiation, together with other risk factors, is a significant cofactor in the occurrence of cataract as an occupational disease among x-ray exposed health care workers. The categories most at risk are radiology technicians,followed by radiologists.

[Rehabilitation methods for children with complicated cataract].

PubMed

Ivanov, G; Cuşnir, V; Septichina, Natalia; Cuşnir, Vitalie

2010-01-01

The work deals with the results of surgical treatment of 155 patients, who had uveal cataract, by method of facoemulsification with artificial crystalline lens transplanting. The age of the sick varied from 3 to 15 as a result of a complex treatment, involving determination of ethnic factor in the development of uveal cataract, before- and after-operation conservative medical treatment, surgical treatment of abscuration ambliopia 78.1% children and the keenness of sight 0.4 and 68.7% got binocularious sight. The study lot of posttraumatic cataract affected children included 189 patients, from them 68 with stationary cataract, 87 with intumescent cataract and 34 with postoperatorial aphakia. Age from 2 to 15 years. 76.3% cases of evolution without postoperatorial complications, in 13.7% intraoperatorial were observed different complications. The work presents the results of surgical treatment 196 of children, who had innate cataract, by the method of facoasoriation with soft intra-eyepiece lens transplanting from 133 patients who had two-sided cataract, 63 had monolateral cataract. All children underwent laser simulation and videocomputer auto-training in post-operation period. As a result of the treatment, 66.8% patients got the amelioration of sight with 0.4, and 58% got binocular sight. The children's age varied between 6 months and 15 years. This article presents a review of the treatment results of 213 children with posttraumatic, congenital and complicated cataracts. The rehabilitation of the patients with the lens pathology includes a complex of measures of early diagnosis, surgery, optimal correction, medical treatment before and after surgery, the prophilaxis and treatment of complications. This approach permits to increase the visual acuity in 83.8% and to restore the binocular vision in 71.4% patients.

Coverage of hospital-based cataract surgery and barriers to the uptake of surgery among cataract blind persons in nigeria: the Nigeria National Blindness and Visual Impairment Survey.

PubMed

Abubakar, Tafida; Gudlavalleti, Murthy V S; Sivasubramaniam, Selvaraj; Gilbert, Clare E; Abdull, Mohammed M; Imam, Abdullahi U

2012-04-01

To determine cataract surgical coverage, and barriers to modern cataract surgery in Nigeria. Multistage stratified cluster random sampling was used to identify a nationally representative sample of 15,027 persons aged 40+ years. All underwent visual acuity testing, frequency doubling technology visual field testing, autorefraction, and measurement of best corrected vision if <6/12 in one or both eyes. An ophthalmologist examined the anterior segment and fundus through an undilated pupil for all participants. Participants were examined by a second ophthalmologist using a slit lamp and dilated fundus examination using a 90 diopter condensing lens if vision was <6/12 in one or both eyes, there were optic disc changes suggestive of glaucoma, and 1 in 7 participants regardless of findings. All those who had undergone cataract surgery were asked where and when this had taken place. Individuals who were severely visually impaired or blind from unoperated cataract were asked to explain why they had not undergone surgery. A total of 13,591 participants were examined (response rate 89.9%). Prevalence of cataract surgery was 1.6% (95% confidence interval 1.4-1.8), significantly higher among those aged ≥70 years. Cataract surgical coverage (persons) in Nigeria was 38.3%. Coverage was 1.7 times higher among males than females. Coverage was only 9.1% among women in the South-South geopolitical zone. Over one third of those who were cataract blind said they could not afford surgery (36%). Cataract surgical coverage in Nigeria was among the lowest in the world. Urgent initiatives are necessary to improve surgical output and access to surgery.

Revalidation and electronic cataract surgery audit: a Scottish survey on current practice and opinion.

PubMed

Megaw, R; Rane-Malcolm, T; Brannan, S; Smith, R; Sanders, R

2011-11-01

To determine current knowledge and opinion on revalidation, and methods of cataract surgery audit in Scotland and to outline the current and future possibilities for electronic cataract surgery audit. In 2010 we conducted a prospective, cross-sectional, Scottish-wide survey on revalidation knowledge and opinion, and cataract audit practice among all senior NHS ophthalmologists. Results were anonymised and recorded manually for analysis. In all, 61% of the ophthalmologists surveyed took part. Only 33% felt ready to take part in revalidation, whereas 76% felt they did not have adequate information about the process. Also, 71% did not feel revalidation would improve patient care, but 85% agreed that cataract surgery audit is essential for ophthalmic practice. In addition, 91% audit their cataract outcomes; 52% do so continuously. Further, 63% audit their subspecialist surgical results. Only 25% audit their cataract surgery practice electronically, and only 12% collect clinical data using a hospital PAS system. Funding and system incompatibility were the main reasons cited for the lack of electronic audit setup. Currently, eight separate hospital IT patient administration systems are used across 14 health boards in Scotland. Revalidation is set to commence in 2012. The Royal College of Ophthalmologists will use cataract outcome audit as a tool to ensure surgical competency for the process. Retrospective manual auditing of cataract outcome is time consuming, and can be avoided with an electronic system. Scottish ophthalmologists view revalidation with scepticism and appear to have inadequate knowledge of the process. However, they strongly agree with the concept of cataract surgery audit. The existing and future electronic applications that may support surgical audit are commercial electronic records, web-based applications, centrally funded software applications, and robust NHS connections between community and hospital.

Willingness to Pay for Cataract Surgery Provided by a Senior Surgeon in Urban Southern China

PubMed Central

Lin, Xianhua; Ling, Yunlan; Lin, Xiaofeng; Li, Mingge; Lamoureux, Ecosse; Zheng, Yingfeng

2015-01-01

Purpose To study willingness to pay for cataract surgery and surgical service provided by a senior cataract surgeon in urban Southern China. Methods This study was a cross-sectional willingness-to-pay (WTP) interview using bidding formats. Two-hundred eleven persons with presenting visual impairment in either eye due to cataract were enrolled at a tertiary eye hospital. Participants underwent a comprehensive eye examination and a WTP interview for both surgery and service provided by a senior surgeon. Demographic information, socioeconomic status and clinical data were recorded. Results Among 211 (98% response rate) persons completing the interview, 53.6% were women and 80.6% were retired. About 72.2% had a monthly income lower than 1000 renminbi (US $161). A total of 189 (89.6%) were willing to pay for cataract and the median amount of WTP was 6000 renminbi (US$968). And 102 (50.7%) were willing to pay additional fees for surgery performed by a senior surgeon, and the median amount of WTP was 500 renminbi (US$81). In regression models adjusting for age and gender, persons with preexisting eye diseases other than cataract, were more likely to pay for cataract surgery and service provided by a senior surgeon (P = 0.04 for both). Conclusions In urban China, cataract patients, especially those with preexisting eye conditions, are willing to pay additional fees for a senior surgeon. Moving to a system where the price of cataract surgery is proportional to the consultant’ skill and expertise is possible and may have a potential impact on waiting list and quality of eye care. Further studies are needed to examine the impact of such pricing system on attitudes and choices of cataract patients. PMID:26575284

Nuclear Cataract Shows Significant Familial Aggregation in an Older Population after Adjustment for Possible Shared Environmental Factors

PubMed Central

Congdon, Nathan; Broman, Karl W.; Lai, Hong; Munoz, Beatriz; Bowie, Heidi; Gilber, Donna; Wojciechowski, Robert; Alston, Christine; West, Sheila K.

2011-01-01

Purpose To quantify the association between siblings in age-related nuclear cataract, after adjusting for known environmental and personal risk factors. Methods All participants (probands) in the Salisbury Eye Evaluation (SEE) project and their locally resident siblings underwent digital slit lamp photography and were administered a questionnaire to assess risk factors for cataract including: age, gender, lifetime sun exposure, smoking and diabetes history, and use of alcohol and medications such as estrogens and steroids. In addition, blood pressure, body mass index, and serum antioxidants were measured in all participants. Lens photographs were graded by trained observers masked to the subjects' identity, using the Wilmer Cataract Grading System. The odds ratio for siblings for affectedness with nuclear cataract and the sibling correlation of nuclear cataract grade, after adjusting for covariates, were estimated with generalized estimating equations. Results Among 307 probands (mean age, 77.6 ± 4.5 years) and 434 full siblings (mean age, 72.4 ± 7.4 years), the average sibship size was 2.7 per family. After adjustment for covariates, the probability of development of nuclear cataract was significantly increased (odds ratio [OR] = 2.07, 95% confidence interval [CI], 1.30–3.30) among individuals with a sibling with nuclear cataract (nuclear grade ≥ 3.0). The final fitted model indicated a magnitude of heritability for nuclear cataract of 35.6% (95% CI: 21.0%–50.3%) after adjustment for the covariates. Conclusions Findings in this study are consistent with a genetic effect for age-related nuclear cataract, a common and clinically significant form of lens opacity. PMID:15223793

Enhancement and restoration of non-uniform illuminated Fundus Image of Retina obtained through thin layer of cataract.

PubMed

Mitra, Anirban; Roy, Sudipta; Roy, Somais; Setua, Sanjit Kumar

2018-03-01

Retinal fundus images are extensively used in manually or without human intervention to identify and analyze various diseases. Due to the comprehensive imaging arrangement, there is a large radiance, reflectance and contrast inconsistency within and across images. A novel method is proposed based on the cataract physical model to reduce the generated blurriness of the fundus image at the time of image acquisition through the thin layer of cataract by the fundus camera. After the blurriness reduction the method is proposed the enhancement procedure of the images with an objective on contrast perfection with no preamble of artifacts. Due to the uneven distribution of thickness of the cataract, the cataract surroundings are first predicted in the domain of frequency. Second, the resultant image of first step enhanced by the intensity histogram equalization in the adapted Hue Saturation Intensity (HSI) color image space such as the gamut problem can be avoided. The concluding image with suitable color and disparity is acquired by using the proposed max-min color correction approach. The result indicates that not only the proposed method can more effectively enhanced the non-uniform image of retina obtain through thin layer of cataract, but also the resulting image show appropriate brightness and saturation and maintain complete color space information. The projected enhancement method has been tested on the openly available datasets and the result evaluated with the standard used image enhancement algorithms and the cataract removal method. Results show noticeable development over existing methods. Cataract often prevents the clinician from objectively evaluating fundus feature. Cataract also affect subjective test. Enhancement and restoration of non-uniform illuminated Fundus Image of Retina obtained through thin layer of Cataract has shown here to be potentially beneficial. Copyright © 2018 Elsevier B.V. All rights reserved.

Amyloid β1-43 Accumulates in the Lens Epithelium of Cortical Opacification in Japanese Patients.

PubMed

Nagai, Noriaki; Mano, Yu; Otake, Hiroko; Shibata, Teppei; Kubo, Eri; Sasaki, Hiroshi

2017-06-01

We investigated the accumulation of amyloid β (Aβ1-40, Aβ1-42, Aβ1-43) in the lens epithelium of patients with opacification of five different types (cortical cataract [COR]; nuclear cataract [NUC]; posterior subcapsular cataract [PSC]; retrodots [RD]; and water clefts [WC]). Samples were collected from Japanese patients taken during cataract surgery; Aβ levels and mRNA expression were determined by ELISA and a real-time RT-PCR method, respectively. Levels of Aβ1-40 and Aβ1-42 in the lens epithelium of patients with COR, NUC, PSC, RD, and WC showed no significant differences in comparison with transparent lens epithelium. Levels of Aβ1-43 in the lens epithelium of patients with PSC and WC were not detected, and NUC and RD were slightly elevated. In contrast to the results in these cataract types, high Aβ1-43 levels were observed in the lens epithelium of patients with COR, and a close relationship was observed between Aβ1-43 levels and the degree of lens opacification (R = 0.8229, n = 6). The levels of Aβ1-43 were also higher in the lens epithelium of patients with mixed-cataract showing cortical opacification, and the Aβ1-43 levels in the lens epithelium of mixed-cataract patients with cortical opacification was significantly higher than in that of mixed-cataract patients without cortical opacification. In addition, the level of an amyloid precursor protein mRNA in the lens epithelium of mixed-cataract patients with cortical opacification was significantly higher than in transparent lens and mixed-cataract patients without cortical opacification. We found high levels of Aβ1-43 accumulation in the lens epithelium of Japanese patients with cortical opacification.

Indication for cataract surgery. Do we have evidence of who will benefit from surgery? A systematic review and meta-analysis.

PubMed

Kessel, Line; Andresen, Jens; Erngaard, Ditte; Flesner, Per; Tendal, Britta; Hjortdal, Jesper

2016-02-01

The need for cataract surgery is expected to rise dramatically in the future due to the increasing proportion of elderly citizens and increasing demands for optimum visual function. The aim of this study was to provide an evidence-based recommendation for the indication of cataract surgery based on which group of patients are most likely to benefit from surgery. A systematic literature search was performed in the MEDLINE, CINAHL, EMBASE and COCHRANE LIBRARY databases. Studies evaluating the outcome after cataract surgery according to preoperative visual acuity and visual complaints were included in a meta-analysis. We identified eight observational studies comparing outcome after cataract surgery in patients with poor (<20/40) and fair (>20/40) preoperative visual acuity. We could not find any studies that compared outcome after cataract surgery in patients with few or many preoperative visual complaints. A meta-analysis showed that the outcome of cataract surgery, evaluated as objective and subjective visual improvement, was independent on preoperative visual acuity. There is a lack of scientific evidence to guide the clinician in deciding which patients are most likely to benefit from surgery. To overcome this shortage of evidence, many systems have been developed internationally to prioritize patients on waiting lists for cataract surgery, but the Swedish NIKE (Nationell Indikationsmodell för Katarakt Ekstraktion) is the only system where an association to the preoperative scoring of a patient has been related to outcome of cataract surgery. We advise that clinicians are inspired by the NIKE system when they decide which patients to operate to ensure that surgery is only offered to patients who are expected to benefit from cataract surgery. © 2015 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Willingness to Pay for Cataract Surgery Provided by a Senior Surgeon in Urban Southern China.

PubMed

Wang, Mei; Zuo, Yajing; Lin, Xianhua; Ling, Yunlan; Lin, Xiaofeng; Li, Mingge; Lamoureux, Ecosse; Zheng, Yingfeng

2015-01-01

To study willingness to pay for cataract surgery and surgical service provided by a senior cataract surgeon in urban Southern China. This study was a cross-sectional willingness-to-pay (WTP) interview using bidding formats. Two-hundred eleven persons with presenting visual impairment in either eye due to cataract were enrolled at a tertiary eye hospital. Participants underwent a comprehensive eye examination and a WTP interview for both surgery and service provided by a senior surgeon. Demographic information, socioeconomic status and clinical data were recorded. Among 211 (98% response rate) persons completing the interview, 53.6% were women and 80.6% were retired. About 72.2% had a monthly income lower than 1000 renminbi (US $161). A total of 189 (89.6%) were willing to pay for cataract and the median amount of WTP was 6000 renminbi (US$968). And 102 (50.7%) were willing to pay additional fees for surgery performed by a senior surgeon, and the median amount of WTP was 500 renminbi (US$81). In regression models adjusting for age and gender, persons with preexisting eye diseases other than cataract, were more likely to pay for cataract surgery and service provided by a senior surgeon (P = 0.04 for both). In urban China, cataract patients, especially those with preexisting eye conditions, are willing to pay additional fees for a senior surgeon. Moving to a system where the price of cataract surgery is proportional to the consultant' skill and expertise is possible and may have a potential impact on waiting list and quality of eye care. Further studies are needed to examine the impact of such pricing system on attitudes and choices of cataract patients.

Clinical study on evaluation of anti-cataract effect of Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in Timira (immature cataract).

PubMed

Bhati, Hitesh; Manjusha, R

2015-01-01

Senile cataract is the leading cause of blindness according to the World Health Report, 1998. Till date no accepted medical treatment is available for cataract. In Ayurveda visual disturbances are described in the context of Timira, Kacha and Linganasha. Timira is an early stage characterized by blurring of vision and Linganasha is end stage where complete loss of vision occurs. Ancient scholars have advocated different Anjana application and oral medications in the Timira and Kacha stage. To study the efficacy of test drugs Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in immature cataract. In this trial patients having Senile Immature Cataract were randomized with equal probability to one of the two treatment Groups A and B (n = 20 each). In Group A Triphaladi Ghana Vati 500 mg internally for 3 months and in Group B Triphaladi Ghana Vati 500 mg internally and Elaneer Kuzhambu Anjana for local application were given. Assessment was done on the basis of blurring of vision, visualization of nonexisting things, difficulty in bright light and dim light or night vision, distant visual acuity, pinhole vision, best corrected visual acuity and cataract grading on slit lamp. Both groups showed statistically significant changes in blurring of vision, difficulty in glare, daytime and bright light, distant visual activity, pinhole vision, and best-corrected visual acuity. Group B also showed significant changes in difficulty in night time, visualization of nonexisting things and in nuclear cataract. The study establishes that test drugs can reduce and control the progress of immature cataract, and combined therapy was found more effective. Chakshushya Rasayana, early diagnosis and proper management on Doshic lines can prevent arrest or delay senile cataract.

Clinical study on evaluation of anti-cataract effect of Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in Timira (immature cataract)

PubMed Central

Bhati, Hitesh; Manjusha, R.

2015-01-01

Introduction: Senile cataract is the leading cause of blindness according to the World Health Report, 1998. Till date no accepted medical treatment is available for cataract. In Ayurveda visual disturbances are described in the context of Timira, Kacha and Linganasha. Timira is an early stage characterized by blurring of vision and Linganasha is end stage where complete loss of vision occurs. Ancient scholars have advocated different Anjana application and oral medications in the Timira and Kacha stage. Aim: To study the efficacy of test drugs Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in immature cataract. Materials and Methods: In this trial patients having Senile Immature Cataract were randomized with equal probability to one of the two treatment Groups A and B (n = 20 each). In Group A Triphaladi Ghana Vati 500 mg internally for 3 months and in Group B Triphaladi Ghana Vati 500 mg internally and Elaneer Kuzhambu Anjana for local application were given. Assessment was done on the basis of blurring of vision, visualization of nonexisting things, difficulty in bright light and dim light or night vision, distant visual acuity, pinhole vision, best corrected visual acuity and cataract grading on slit lamp. Results: Both groups showed statistically significant changes in blurring of vision, difficulty in glare, daytime and bright light, distant visual activity, pinhole vision, and best-corrected visual acuity. Group B also showed significant changes in difficulty in night time, visualization of nonexisting things and in nuclear cataract. Conclusion: The study establishes that test drugs can reduce and control the progress of immature cataract, and combined therapy was found more effective. Chakshushya Rasayana, early diagnosis and proper management on Doshic lines can prevent arrest or delay senile cataract. PMID:27313415

Hereditary pediatric cataract on the Arabian Peninsula

PubMed Central

Khan, Arif O.

2011-01-01

Hereditary pediatric cataract on the Arabian Peninsula does not follow the same epidemiological patterns as described for Western populations. This article describes selected genetic causes for inherited pediatric cataract in the region. PMID:23960971

Pediatric cataract

PubMed Central

Khokhar, Sudarshan Kumar; Pillay, Ganesh; Dhull, Chirakshi; Agarwal, Esha; Mahabir, Manish; Aggarwal, Pulak

2017-01-01

Pediatric cataract is a leading cause of childhood blindness. Untreated cataracts in children lead to tremendous social, economical, and emotional burden to the child, family, and society. Blindness related to pediatric cataract can be treated with early identification and appropriate management. Most cases are diagnosed on routine screening whereas some may be diagnosed after the parents have noticed leukocoria or strabismus. Etiology of pediatric cataract is varied and diagnosis of specific etiology aids in prognostication and effective management. Pediatric cataract surgery has evolved over years, and with improving knowledge of myopic shift and axial length growth, outcomes of these patients have become more predictable. Favorable outcomes depend not only on effective surgery, but also on meticulous postoperative care and visual rehabilitation. Hence, it is the combined effort of parents, surgeons, anesthesiologists, pediatricians, and optometrists that can make all the difference. PMID:29208814

Paediatric cataract blindness in the developing world: surgical techniques and intraocular lenses in the new millennium

PubMed Central

Wilson, M E; Pandey, S K; Thakur, J

2003-01-01

Paediatric cataract blindness presents an enormous problem to developing countries in terms of human morbidity, economic loss, and social burden. Managing cataracts in children remains a challenge: treatment is often difficult, tedious, and requires a dedicated team effort. To assure the best long term outcome for cataract blind children, appropriate paediatric surgical techniques need to be defined and adopted by ophthalmic surgeons of developing countries. The high cost of operative equipment and the uneven world distribution of ophthalmologists, paediatricians, and anaesthetists create unique challenges. This review focuses on issues related to paediatric cataract management that are appropriate and suitable for ophthalmic surgeons in the developing world. Practical guidelines and recommendations have also been provided for ophthalmic surgeons and health planners dealing with childhood cataract management in the developing world. PMID:12488254

EPHA2 Polymorphisms in Estonian Patients with Age-Related Cataract.

PubMed

Celojevic, Dragana; Abramsson, Alexandra; Seibt Palmér, Mona; Tasa, Gunnar; Juronen, Erkki; Zetterberg, Henrik; Zetterberg, Madeleine

2016-01-01

Ephrin receptors (Ephs) are tyrosine kinases that together with their ligands, ephrins, are considered important in cell-cell communication, especially during embryogenesis but also for epithelium homeostasis. Studies have demonstrated the involvement of mutations or common variants of the gene encoding Eph receptor A2 (EPHA2), in congenital cataract and in age-related cataract. This study investigated a number of disease-associated single nucleotide polymorphisms (SNPs) in EPHA2 in patients with age-related cataract. The study included 491 Estonian patients who had surgery for age-related cataract, classified as nuclear, cortical, posterior subcapsular and mixed lens opacities, and 185 controls of the same ethnical origin. Seven SNPs in EPHA2 (rs7543472, rs11260867, rs7548209, rs3768293, rs6603867, rs6678616, rs477558) were genotyped using TaqMan Allelic Discrimination. Statistical analyses for single factor associations used χ(2)-test and logistic regression was performed including relevant covariates (age, sex and smoking). In single-SNP allele analysis, only the rs7543472 showed a borderline significant association with risk of cataract (p = 0.048). Regression analysis with known risk factors for cataract showed no significant associations of the studied SNPs with cataract. Stratification by cataract subtype did not alter the results. Adjusted odds ratios were between 0.82 and 1.16 (95% confidence interval 0.61-1.60). The present study does not support a major role of EphA2 in cataractogenesis in an Estonian population.

Simultaneous vs sequential bilateral cataract surgery for infants with congenital cataracts: Visual outcomes, adverse events, and economic costs.

PubMed

Dave, Hreem; Phoenix, Vidya; Becker, Edmund R; Lambert, Scott R

2010-08-01

To compare the incidence of adverse events and visual outcomes and to compare the economic costs of sequential vs simultaneous bilateral cataract surgery for infants with congenital cataracts. Retrospective review of simultaneous vs sequential bilateral cataract surgery for infants with congenital cataracts who underwent cataract surgery when 6 months or younger at our institution. Records were available for 10 children who underwent sequential surgery at a mean age of 49 days for the first eye and 17 children who underwent simultaneous surgery at a mean age of 68 days (P = .25). We found a similar incidence of adverse events between the 2 treatment groups. Intraoperative or postoperative complications occurred in 14 eyes. The most common postoperative complication was glaucoma. No eyes developed endophthalmitis. The mean (SD) absolute interocular difference in logMAR visual acuities between the 2 treatment groups was 0.47 (0.76) for the sequential group and 0.44 (0.40) for the simultaneous group (P = .92). Payments for the hospital, drugs, supplies, and professional services were on average 21.9% lower per patient in the simultaneous group. Simultaneous bilateral cataract surgery for infants with congenital cataracts is associated with a 21.9% reduction in medical payments and no discernible difference in the incidence of adverse events or visual outcomes. However, our small sample size limits our ability to make meaningful comparisons of the relative risks and visual benefits of the 2 procedures.

A Comparison of Endothelial Cell Loss in Combined Cataract and MIGS (Hydrus) Procedure to Phacoemulsification Alone: 6-Month Results

PubMed Central

Fea, Antonio M.; Consolandi, Giulia; Pignata, Giulia; Cannizzo, Paola Maria Loredana; Lavia, Carlo; Billia, Filippo; Rolle, Teresa; Grignolo, Federico M.

2015-01-01

Purpose. To compare the corneal endothelial cell loss after phacoemulsification, alone or combined with microinvasive glaucoma surgery (MIGS), in nonglaucomatous versus primary open angle glaucoma (POAG) eyes affected by age-related cataract. Methods. 62 eyes of 62 patients were divided into group 1 (n = 25, affected by age-related cataract) and group 2 (n = 37, affected by age-related cataract and POAG). All patients underwent cataract surgery. Group 2 was divided into subgroups A (n = 19, cataract surgery alone) and B (n = 18, cataract surgery and MIGS). Prior to and 6 months after surgery the patients' endothelium was studied. Main outcomes were CD (cell density), SD (standard deviation), CV (coefficient of variation), and 6A (hexagonality coefficient) variations after surgeries. Results. There were no significant differences among the groups concerning preoperative endothelial parameters. The differences in CD before and after surgery were significant in all groups: 9.1% in group 1, 17.24% in group 2A, and 11.71% in group 2B. All endothelial parameters did not significantly change after surgery. Conclusions. Phacoemulsification determined a loss of endothelial cells in all groups. After surgery the change in endothelial parameters after MIGS was comparable to the ones of patients who underwent cataract surgery alone. PMID:26664740

Macroeconomic landscape of refractive surgery in the United States.

PubMed

Corcoran, Kevin J

2015-07-01

This review examines the economic history of refractive surgery and the decline of laser-assisted in-situ keratomileusis (LASIK) in the USA, and the emergence of refractive cataract surgery as an area of growth. Since it peaked in 2007 at 1.4 million procedures per year, LASIK has declined 50% in the USA, whereas refractive cataract surgery, including presbyopia-correcting intraocular lenses (IOLs), astigmatism-correcting IOLs, and femtosecond laser-assisted cataract surgery, has grown to 350 000 procedures per year, beginning in 2003. Patients are price-sensitive and responsive to publicity (good or bad) about refractive surgery and refractive cataract surgery. LASIK's decline has been partially offset by the emergence of refractive cataract surgery. About 11% of all cataract surgery in the USA involves presbyopia-correcting IOLs, astigmatism-correcting IOLs, or a femtosecond laser. From the surgeon's perspective, there are high barriers to entry into the marketplace for refractive surgery and refractive cataract surgery due to the high capital cost of excimer and femtosecond lasers, the high skill level required to deliver spectacular results to demanding patients who pay out of pocket, and the necessity to perform a high volume of surgeries to satisfy both of these requirements. Probably, less than 7% of US cataract surgeons can readily meet all of these requirements.

[Pay attention to the complexity of cataract surgery of no vitreous eyes].

PubMed

Bao, Y Z

2017-04-11

With wide-spread performance of pars plana vitrectomy, cataract surgeries with no vitreous are getting more and more. This kind of surgery has great difference between individuals and it lacks randomized large sample clinical trial. Surgical strategy decision was basically relied on the surgeon's personal experience. We should fully aware the individual and common characteristics of no vitreous cataract surgery. Surgical time should be carefully decided. Complete ocular examination, evaluation, design of cataract surgical procedure and appropriate intra-ocular lens selection are needed. We must pay highly attention on the cataract surgery of no vitreous eyes. (Chin J Ophthalmol, 2017, 53: 241-243) .

Resident and young physician experience with complex cataract surgery and new cataract and refractive technology: Results of the ASCRS 2016 Young Eye Surgeons survey.

PubMed

Schallhorn, Julie M; Ciralsky, Jessica B; Yeu, Elizabeth

2017-05-01

A survey was offered to attendees of the 2016 annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS) as well as online to ASCRS members. Of the 429 self-identified surgeons in training or those with fewer than 5 years in practice, 83% had performed complex cataract surgery using iris expansion devices or capsular tension rings (63%) and 70% had implanted a toric intraocular lens (IOL). A minority of respondents had performed laser-assisted cataract surgery (27%) or implanted presbyopia-correcting IOLs (39%), and only half (50%) had performed laser vision correction (LVC). Comfort with complex cataract and IOL procedures improved with increasing number of cases performed until greater than 10 cases. From this we can conclude that young surgeons have adequate exposure to complex cataracts but lack experience in refractive surgery and new IOL technology. Reported surgeon confidence improved with increased experience and exposure. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Light-focusing human micro-lenses generated from pluripotent stem cells model lens development and drug-induced cataract in vitro

PubMed Central

Murphy, Patricia; Kabir, Md Humayun; Srivastava, Tarini; Mason, Michele E.; Dewi, Chitra U.; Lim, Seakcheng; Yang, Andrian; Djordjevic, Djordje; Killingsworth, Murray C.; Ho, Joshua W. K.; Harman, David G.

2018-01-01

ABSTRACT Cataracts cause vision loss and blindness by impairing the ability of the ocular lens to focus light onto the retina. Various cataract risk factors have been identified, including drug treatments, age, smoking and diabetes. However, the molecular events responsible for these different forms of cataract are ill-defined, and the advent of modern cataract surgery in the 1960s virtually eliminated access to human lenses for research. Here, we demonstrate large-scale production of light-focusing human micro-lenses from spheroidal masses of human lens epithelial cells purified from differentiating pluripotent stem cells. The purified lens cells and micro-lenses display similar morphology, cellular arrangement, mRNA expression and protein expression to human lens cells and lenses. Exposing the micro-lenses to the emergent cystic fibrosis drug Vx-770 reduces micro-lens transparency and focusing ability. These human micro-lenses provide a powerful and large-scale platform for defining molecular disease mechanisms caused by cataract risk factors, for anti-cataract drug screening and for clinically relevant toxicity assays. PMID:29217756

Light-focusing human micro-lenses generated from pluripotent stem cells model lens development and drug-induced cataract in vitro.

PubMed

Murphy, Patricia; Kabir, Md Humayun; Srivastava, Tarini; Mason, Michele E; Dewi, Chitra U; Lim, Seakcheng; Yang, Andrian; Djordjevic, Djordje; Killingsworth, Murray C; Ho, Joshua W K; Harman, David G; O'Connor, Michael D

2018-01-09

Cataracts cause vision loss and blindness by impairing the ability of the ocular lens to focus light onto the retina. Various cataract risk factors have been identified, including drug treatments, age, smoking and diabetes. However, the molecular events responsible for these different forms of cataract are ill-defined, and the advent of modern cataract surgery in the 1960s virtually eliminated access to human lenses for research. Here, we demonstrate large-scale production of light-focusing human micro-lenses from spheroidal masses of human lens epithelial cells purified from differentiating pluripotent stem cells. The purified lens cells and micro-lenses display similar morphology, cellular arrangement, mRNA expression and protein expression to human lens cells and lenses. Exposing the micro-lenses to the emergent cystic fibrosis drug Vx-770 reduces micro-lens transparency and focusing ability. These human micro-lenses provide a powerful and large-scale platform for defining molecular disease mechanisms caused by cataract risk factors, for anti-cataract drug screening and for clinically relevant toxicity assays. © 2018. Published by The Company of Biologists Ltd.

Visual functions of commercial drivers in relation to road accidents in Nigeria

PubMed Central

Oladehinde, M. K.; Adeoye, A. O.; Adegbehingbe, B. O.; Onakoya, A. O.

2007-01-01

Objective: To determine the effects of the visual functions on the occurrence of road traffic accidents (RTA) amongst commercial drivers in Ife central local government area (LGA) of Osun state of Nigeria. Design: A cross-sectional study. Settings: Four major motor parks located at Ife Central LGA. Materials and Methods: Of the estimated 270 commercial drivers in the four major parks of the LGA, 215 consecutive drivers were interviewed and had their eyes examined. Structured questionnaires were administered by an ophthalmologist. Results: The prevalence of visual impairment (visual acuity < 6/18) in the better eye without correction was 3.3% ± 2.4 and there was a significant association between uncorrected visual acuity impairment in the better eye and RTA (P = 0.0152). Refractive error was seen in 8.4% of the drivers, but none of these wear corrective glasses. Visual field defect, abnormal stereopsis and color vision impairment did not have any significant association with RTA. Conclusion: Poor visual acuity is strongly associated with RTA amongst Nigerian commercial drivers as opposed to visual field defect, abnormal color vision and stereopsis. A significant proportion of visual impairment was due to uncorrected refractive errors. PMID:21938219

Stereopsidales - A New Order of Mushroom-Forming Fungi

PubMed Central

Sjökvist, Elisabet; Pfeil, Bernard E.; Larsson, Ellen; Larsson, Karl-Henrik

2014-01-01

One new order, one new family, and one new combination are presented, as the result of molecular phylogenetic analyses. The new order Stereopsidales and the new family Stereopsidaceae are described incorporating Stereopsis radicans and S. globosa, formerly Clavulicium globosum. We show that not only do these species represent an old overlooked lineage, but both species harbor cryptic diversity. In addition, a third species, C. macounii, appears as a plausible sister to the new lineage, but there is conflict in the data. All specimens of S. radicans and S. globosa analysed here are from the South and Central Americas; several records of S. radicans have been made also from tropical Asia. We expect the true diversity in this group to be a lot higher than presented in this paper. Stereopsis radicans was formerly included in Polyporales, but a placement within that order is rejected by our data through SH tests. The dataset consisted of four nuclear markers: rpb2, tef1, LSU and SSU, each of which was analysed separately using maximum likelihood and Bayesian inference. Recombination detection tests indicate no plausible recombinations. The potential of S. radicans, S. globosa and C. macounii being amphitallic is briefly discussed. PMID:24777067

The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study

PubMed Central

2013-01-01

Background To screen for visual impairment in Malaysian preschool children. Methods Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. Results The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). Conclusion The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group. PMID:23601160

Vision training methods for sports concussion mitigation and management.

PubMed

Clark, Joseph F; Colosimo, Angelo; Ellis, James K; Mangine, Robert; Bixenmann, Benjamin; Hasselfeld, Kimberly; Graman, Patricia; Elgendy, Hagar; Myer, Gregory; Divine, Jon

2015-05-05

There is emerging evidence supporting the use vision training, including light board training tools, as a concussion baseline and neuro-diagnostic tool and potentially as a supportive component to concussion prevention strategies. This paper is focused on providing detailed methods for select vision training tools and reporting normative data for comparison when vision training is a part of a sports management program. The overall program includes standard vision training methods including tachistoscope, Brock's string, and strobe glasses, as well as specialized light board training algorithms. Stereopsis is measured as a means to monitor vision training affects. In addition, quantitative results for vision training methods as well as baseline and post-testing *A and Reaction Test measures with progressive scores are reported. Collegiate athletes consistently improve after six weeks of training in their stereopsis, *A and Reaction Test scores. When vision training is initiated as a team wide exercise, the incidence of concussion decreases in players who participate in training compared to players who do not receive the vision training. Vision training produces functional and performance changes that, when monitored, can be used to assess the success of the vision training and can be initiated as part of a sports medical intervention for concussion prevention.

The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study.

PubMed

Premsenthil, Mallika; Manju, Rose; Thanaraj, Asokumaran; Rahman, Syed Alwi Syed Abdul; Kah, Tan Aik

2013-04-19

To screen for visual impairment in Malaysian preschool children. Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group.

Adaptive Neuromorphic Circuit for Stereoscopic Disparity Using Ocular Dominance Map

PubMed Central

Sharma, Sheena; Gupta, Priti; Markan, C. M.

2016-01-01

Stereopsis or depth perception is a critical aspect of information processing in the brain and is computed from the positional shift or disparity between the images seen by the two eyes. Various algorithms and their hardware implementation that compute disparity in real time have been proposed; however, most of them compute disparity through complex mathematical calculations that are difficult to realize in hardware and are biologically unrealistic. The brain presumably uses simpler methods to extract depth information from the environment and hence newer methodologies that could perform stereopsis with brain like elegance need to be explored. This paper proposes an innovative aVLSI design that leverages the columnar organization of ocular dominance in the brain and uses time-staggered Winner Take All (ts-WTA) to adaptively create disparity tuned cells. Physiological findings support the presence of disparity cells in the visual cortex and show that these cells surface as a result of binocular stimulation received after birth. Therefore, creating in hardware cells that can learn different disparities with experience not only is novel but also is biologically more realistic. These disparity cells, when allowed to interact diffusively on a larger scale, can be used to adaptively create stable topological disparity maps in silicon. PMID:27243029

[Clinical observation on the relation between laser in situ keratomileusis treating myopic anisometropia and binocular vision].

PubMed

Huang, Jing; Lu, Wei

2009-09-29

To analyze the effect of LASIK on visual quality of anisometropia, and evaluate its clinical value in the view of visual quality. Prospective observational case series. Assayed the naked vision, glasses-corrected vision and binocular vision of 45 cases with anisometropia >or= 2.25D before and after the operation of LASIK. 91.57% of the eyes after the operation reached the vision >or= 0.8, which says a significant improvement for binocular vision after the operation (P < 0.05). There was a significant difference on diopter between the pre-operation and post-operation (P < 0.05). As for anisometropia, there was no significant difference between simultaneous binocular visions (P = 0.431), but there was of great significance among combined, short and long distance stereopsis visions (P = 0.000). Binocular vision deteriorated as anisometropia increased (P < 0.05). The short distance stereopsis visions of LASIK-treated myopic anisometropia were better than that of glasses-corrected patients (P < 0.05). The operation of LASIK can improve the visual quality and resume the binocular vision. LASIK can correct anisometropia and its therapeutic efficacy deserves to confirm.

Glaucoma and cataract surgery: two roads merging into one.

PubMed

Shah, Manjool; Law, Geoffrey; Ahmed, Iqbal Ike K

2016-01-01

To discuss the increasing utilization of cataract extraction in the management of glaucoma and to highlight advances in surgical care that can promote synergistic treatment of these comorbid conditions. Recent years have demonstrated significant advances in the management of glaucoma through the use of novel microinvasive glaucoma devices. Furthermore, an increased understanding of the role of cataract surgery in the treatment of various glaucomas warrants review. Nevertheless, cataract surgery in the glaucoma patient warrants specific preoperative, intraoperative, and postoperative planning to optimize visual function and quality of life while mitigating potential risk factors for adverse events. Although the challenges of performing cataract extraction on glaucoma patients exist, the potential benefit to these patients is substantial. With attention to pre- and perioperative surgical planning and intraoperative technique, as well as with awareness and potential utilization of novel devices and treatment strategies, cataract extraction offers a unique platform for anatomical and functional improvement in this increasingly common cohort of patients.

Bacterial endophthalmitis after resident-performed cataract surgery.

PubMed

Hollander, David A; Vagefi, M Reza; Seiff, Stuart R; Stewart, Jay M

2006-05-01

To determine if there is an increased rate of postoperative bacterial endophthalmitis after resident-performed cataract extraction relative to the reported rates of experienced surgeons. Retrospective, observational case series. The operative reports of the resident-performed cataract surgeries at San Francisco General Hospital between 1983 and 2002 were reviewed. Cases of culture-positive bacterial endophthalmitis and vitreous loss were identified. Between 1983 and 2002, three cases (0.11%) of culture-positive bacterial endophthalmitis occurred after 2718 resident-performed cataract extractions. The overall vitreous loss rate was 6.7%. Two endophthalmitis cases were acute (Staphylococcus epidermidis, Streptococcus viridans), presenting within five days of surgeries complicated by vitreous loss, and one case was delayed-onset (Corynebacterium species) after Nd:YAG posterior capsulotomy after uncomplicated cataract extraction. Despite higher rates of vitreous loss, the rate of endophthalmitis following resident-performed cataract surgery remains comparable with the rates of more experienced surgeons.

Rapid assessment of cataract surgical coverage in rural Zululand.

PubMed

Rotchford, A P; Johnson, G J

2000-10-01

Cataract surgical coverage (CSC) is a useful indicator of the degree of success of a cataract intervention programme. However, because previously described methods are time-consuming and labour-intensive, they are rarely performed. This study describes a simple and inexpensive assessment of CSC based on screening of pensioners at pension delivery sites in a rural district. Random cluster-based cross-sectional survey. State pension distribution sites in Hlabisa, a rural district in KwaZulu-Natal, South Africa. 562 old-age pensioners. Subjects found to be blind (visual acuity < 3/60) and those reporting a history of eye surgery were examined using a torch and direct ophthalmoscope by an ophthalmologist. Cases of blindness due to operable cataract and post-cataract surgical subjects were identified. CSC was found to be 38.5% (95% confidence interval 29.1-47.9%). Blindness prevalence was 10.3%, with 69.0% due to cataract.

Nutritional modulation of cataract

PubMed Central

Weikel, Karen A; Garber, Caren; Baburins, Alyssa; Taylor, Allen

2014-01-01

Lens opacification or cataract reduces vision in over 80 million people worldwide and blinds 18 million. These numbers will increase dramatically as both the size of the elderly demographic and the number of those with carbohydrate metabolism-related problems increase. Preventative measures for cataract are critical because the availability of cataract surgery in much of the world is insuficient. Epidemiologic literature suggests that the risk of cataract can be diminished by diets that are optimized for vitamin C, lutein/zeaxanthin, B vitamins, omega-3 fatty acids, multivitamins, and carbohydrates: recommended levels of micronutrients are salutary. The limited data from intervention trials provide some support for observational studies with regard to nuclear – but not other types of – cataracts. Presented here are the beneficial levels of nutrients in diets or blood and the total number of participants surveyed in epidemiologic studies since a previous review in 2007. PMID:24279748

Oxidative stress markers in aqueous humor of patients with senile cataracts.

PubMed

Sawada, Hideko; Fukuchi, Takeo; Abe, Haruki

2009-01-01

To investigate the levels of oxidative stress markers in human eyes with senile cataracts. We conducted a retrospective, case-controlled study of 57 patients with senile cataracts. To assess oxidative stress markers in the eye, we measured the enzymatic activities of superoxide dismutase (SOD) and catalase (CAT) as well as the total protein levels in aqueous humor. In aqueous humor, SOD and CAT activity levels were 0.133 +/- 0.020 and 1.223 +/- 0.081 U/ml, respectively; protein levels were 2.372 +/- 0.166 mg/ml (means +/- SEM). We observed a significant increase in SOD activity and the protein level in progressed nuclear cataracts. No significant age-associated difference in antioxidant enzyme levels was detected. Significant increases in the levels of SOD activity and total protein correlated with the severity of the cataract but not with patient age, suggesting that progressed cataract is associated with molecules leaking from the lens capsule.

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery.

PubMed

García-Layana, Alfredo; Ciufo, Gianfranco; Toledo, Estefania; Martínez-González, Miguel A; Corella, Dolores; Fitó, Montse; Estruch, Ramon; Gómez-Gracia, Enrique; Fiol, Miguel; Lapetra, José; Serra-Majem, Lluís; Pintó, Xavier; Portillo, Maria P; Sorli, José V; Bulló, Mónica; Vinyoles, Ernest; Sala-Vila, Aleix; Ros, Emilio; Salas-Salvadó, Jordi; Arós, Fernando

2017-05-03

Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects. We included 5802 men and women (age range: 55-80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) ( n = 1998); (2) a MedDiet enriched with nuts ( n = 1914), and a control group recommended to follow a low-fat diet ( n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery. During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84-1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86-1.31, p = 0.58) for the control group versus the MedDiet + Nuts group. To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery.

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

PubMed Central

García-Layana, Alfredo; Ciufo, Gianfranco; Toledo, Estefania; Martínez-González, Miguel A.; Corella, Dolores; Fitó, Montse; Estruch, Ramon; Gómez-Gracia, Enrique; Fiol, Miguel; Lapetra, José; Serra-Majem, Lluís; Pintó, Xavier; Portillo, Maria P.; Sorli, José V.; Bulló, Mónica; Vinyoles, Ernest; Sala-Vila, Aleix; Ros, Emilio; Salas-Salvadó, Jordi; Arós, Fernando

2017-01-01

Background: Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects. Methods: We included 5802 men and women (age range: 55–80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery. Results: During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84–1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86–1.31, p = 0.58) for the control group versus the MedDiet + Nuts group. Conclusions: To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery. PMID:28467363

Cosmic Radiation and Cataracts in Airline Pilots

NASA Astrophysics Data System (ADS)

Rafnsson, V.; Olafsdottir, E.; Hrafnkelsson, J.; de Angelis, G.; Sasaki, H.; Arnarson, A.; Jonasson, F.

Nuclear cataracts have been associated with ionising radiation exposure in previous studies. A population based case-control study on airline pilots has been performed to investigate whether employment as a commercial pilot and consequent exposure to cosmic radiation were associated to lens opacification, when adjusted for known risk factors for cataracts. Cases of opacification of the ocular lens were found in surveys among pilots and a random sample of the Icelandic population. Altogether 445 male subjects underwent a detailed eye examination and answered a questionnaire. Information from the airline company on the 79 pilots employment time, annual hours flown per aircraft type, the timetables and the flight profiles made calculation of individual cumulated radiation dose (mSv) possible. Lens opacification were classified and graded according to WHO simplified cataracts grading system using slit lamp. The odds ratio from logistic regression of nuclear cataracts risk among cases and controls was 3.02 (95% CI 1.44 to 6.35) for pilots compared with non-pilots, adjusted for age, smoking and sunbathing habits, whereas that of cortical cataracts risk among cases and controls was lower than unity (non significant) for pilots compared with non-pilots in a logistic regression analysis adjusted for same factors. Length of employment as a pilot and cumulated radiation dose (mSv) were significantly related to the risk of nuclear cataracts. So the association between radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking and sunbathing habits, indicates that cosmic radiation may be cause of nuclear cataract among commercial pilots.

Three-Dimensional Cataract Crystalline Lens Imaging With Swept-Source Optical Coherence Tomography.

PubMed

de Castro, Alberto; Benito, Antonio; Manzanera, Silvestre; Mompeán, Juan; Cañizares, Belén; Martínez, David; Marín, Jose María; Grulkowski, Ireneusz; Artal, Pablo

2018-02-01

To image, describe, and characterize different features visible in the crystalline lens of older adults with and without cataract when imaged three-dimensionally with a swept-source optical coherence tomography (SS-OCT) system. We used a new SS-OCT laboratory prototype designed to enhance the visualization of the crystalline lens and imaged the entire anterior segment of both eyes in two groups of participants: patients scheduled to undergo cataract surgery, n = 17, age range 36 to 91 years old, and volunteers without visual complains, n = 14, age range 20 to 81 years old. Pre-cataract surgery patients were also clinically graded according to the Lens Opacification Classification System III. The three-dimensional location and shape of the visible opacities were compared with the clinical grading. Hypo- and hyperreflective features were visible in the lens of all pre-cataract surgery patients and in some of the older adults in the volunteer group. When the clinical examination revealed cortical or subcapsular cataracts, hyperreflective features were visible either in the cortex parallel to the surfaces of the lens or in the posterior pole. Other type of opacities that appeared as hyporeflective localized features were identified in the cortex of the lens. The OCT signal in the nucleus of the crystalline lens correlated with the nuclear cataract clinical grade. A dedicated OCT is a useful tool to study in vivo the subtle opacities in the cataractous crystalline lens, revealing its position and size three-dimensionally. The use of these images allows obtaining more detailed information on the age-related changes leading to cataract.

Factors Associated with Complications and Postoperative Visual Outcomes of Cataract Surgery; a Study of 1,632 Cases

PubMed Central

Thanigasalam, Thevi; Reddy, Sagili Chandrashekara; Zaki, Rafdzah Ahmad

2015-01-01

Purpose: Cataract surgery is the most common intraocular surgery performed all over the world and has advanced technically in recent years. As in all surgeries, complications are unavoidable. Herein we report factors associated with complications and visual outcomes of cataract surgery. Methods: This retrospective cohort study included data of 1,632 cataract surgeries performed from 2007 to 2010 which was obtained from the cataract registry of the Malaysian National Eye Database. Demographic features, ocular and systemic comorbidites, grade of surgeon expertise and duration of surgery, type of anesthesia, intraoperative and postoperative complications, and the type of intraocular lens were recorded. Best corrected visual acuities were compared before and after the operation. Results: Mean patient age was 66.9 years with equal gender distribution. The majority of subjects had age related cataracts. Phacoemulsification was done faster than other surgeries, especially by specialist surgeons. History of prior ocular surgery and operations performed under general anesthesia were associated with greater complications. Phacoemulsification was associated with less complications and better visual outcomes. The age and etiology of cataract did not affect complications. Malays, absence of ocular comorbidities, left eyes and eyes operated under local anesthesia were more likely to experience more visual improvement. Gender, age, cause of cataract, systemic comorbidities and surgeon expertise as well as intra-and postoperative complications did not affect the visual outcomes. Conclusion: Phacoemulsification had good visual outcomes in cataract surgery. Duration of surgery, expertise of the surgeon and complications did not affect the visual outcomes. PMID:27051481

Recurrent mutation in the crystallin alpha A gene associated with inherited paediatric cataract.

PubMed

Javadiyan, Shari; Craig, Jamie E; Souzeau, Emmanuelle; Sharma, Shiwani; Lower, Karen M; Pater, John; Casey, Theresa; Hodson, Trevor; Burdon, Kathryn P

2016-02-11

Cataract is a major cause of childhood blindness worldwide. The purpose of this study was to determine the genetic cause of paediatric cataract in a South Australian family with a bilateral lamellar paediatric cataract displaying variable phenotypes. Fifty-one genes implicated in congenital cataract in human or mouse were sequenced in an affected individual from an Australian (Caucasian) family using a custom Ampliseq library on the Ion Torrent Personal Genome Machine. Reads were mapped against the human genome (hg19) and variants called with the Torrent Suite software. Variants were annotated to dbSNP 137 using Ion Reporter (IR 1.6.2) and were prioritised for validation if they were novel or rare and were predicted to be protein changing. We identified a previously reported oligomerization disrupting mutation, c.62G > A (p.R21Q), in the Crystallin alpha A (CRYAA) gene segregating in this three generation family. No other novel or rare coding mutations were detected in the known cataract genes sequenced. Microsatellite markers were used to compare the haplotypes between the family reported here and a previously published family with the same segregating mutation. Haplotype analysis indicated a potential common ancestry between the two South Australian families with this mutation. The work strengthens the genotype-phenotype correlations between this functional mutation in the crystallin alpha A (CRYAA) gene and paediatric cataract. The p.R21Q mutation is the most likely cause of paediatric cataract in this family. The recurrence of this mutation in paediatric cataract families is likely due to a familial relationship.

[Outcome of cataract surgery in patients with pigmentary retinal degeneration].

PubMed

Grześk, Magdalena; Kałuzny, Józef; Malukiewicz-Wiśniewska, Grazyna

2007-01-01

To evaluate the results of cataract surgery in patients with RP because retinitis pigmentosa is one of the disease entities that belongs to tapeto-retinal degenerations. The occurrence of RP appearance is 1:4000 to 1:3000. Twenty patients with RP (7 women and 13 men, 33 eyes), who underwent cataract surgery were examined retrospectively. Average age in our group was 46.6 years. Visual acuity, intraocular pressure, slip lamp examination, fundus examination, cataract morphology, visual field were taken before surgery and on discharge, on the basis of medical documentation. Control examination was taken, on average, eighty one months after cataract surgery. Nine eyes were operated by phacoemulsification, 24 eyes by means of extracapsular cataract extraction. In the same way control group of 18 patients who underwent cataract surgery without RP (33 eyes) was examined. In RP group in 63.6% patients on discharge from the hospital and in 60.6% patients during the control examination, improvement of visual acuity was revealed. Deterioration was noted in 18.2% of patients on discharge from hospital and in 24.2% of patients during the control examination. In the control group improvement of visual acuity was revealed in 90.9% of patients on discharge and in 97% patients during the control examination, whereas deterioration of visual acuity occurred in 6.1% patients on discharge and in 3% patients during the check examination. In patients with retinitis pigmentosa cataract occurs earlier then in the control group. Cataract surgery for relatively minor opacities is beneficial in patients with RP, and causes improvement of visual acuity in most of eyes undergoing surgery.

A Mutation in the Start Codon of γ-Crystallin D Leads to Nuclear Cataracts in the Dahl SS/Jr-Ctr Strain

PubMed Central

Johnson, Ashley C.; Lee, Jonathan W.; Harmon, Ashlyn C.; Morris, Zaliya; Wang, Xuexiang; Fratkin, Jonathan; Rapp, John P.; Gomez-Sanchez, Elise; Garrett, Michael R.

2013-01-01

Cataracts are a major cause of blindness. The most common forms of cataracts are age and UV related and develops mostly in the elderly, while congenital cataracts appear at birth or in early childhood. The Dahl salt-sensitive (SS/Jr) rat is an extensively used model of salt-sensitive hypertension that exhibits concomitant renal disease. In the mid 1980’s, cataracts appeared in a few animals in the Dahl S colony, presumably the result of a spontaneous mutation. The mutation was fixed and bred to establish the SS/Jr-Ctr substrain. The SS/Jr-Ctr substrain has been exclusively used by a single investigator to study the role of steroids and hypertension. Using a classical positional cloning approach, we localized the cataract gene with high-resolution to a less than 1 Mbp region on chromosome 9 using an F1 (SS/Jr-Ctr X SHR) X SHR backcross population. The 1 Mbp region contained only 13 genes, including 4 genes from the γ-crystallins (Cryg) gene family which are known to play a role in cataract formation. All of the γ-crystallins were sequenced and a novel point mutation in the start codon (ATG → GTG) of the Crygd gene was identified which led to the complete absence of CRYGD protein in the eyes of the SS/Jr-Ctr strain. In summary, the identification of the genetic cause in this novel cataract model may provide an opportunity to better understand the development of cataracts, particularly in the context of hypertension. PMID:23404175

Ophthalmic nepafenac use in the Netherlands and Denmark.

PubMed

Margulis, Andrea V; Houben, Eline; Hallas, Jesper; Overbeek, Jetty A; Pottegård, Anton; Torp-Pedersen, Tobias; Perez-Gutthann, Susana; Arana, Alejandro

2017-08-01

To describe nepafenac use in the Netherlands and Denmark with reference to its approved indications. For context, we also describe the use of ketorolac and diclofenac. We identified users in the PHARMO Database Network (the Netherlands, 2008-2013) and the Danish national health registers (Denmark, 1994-2014). We described prevalence of cataract surgery and duration of use in patients with cataract surgery with and without diabetes. In the Netherlands, 9530 nepafenac users (mean age, 71 years; 60% women) contributed 12 691 therapy episodes, of which 21% had a recently recorded cataract surgery. Of 2266 episodes in adult non-diabetic patients with cataract surgery, 60% had one bottle dispensed (treatment duration ≤21 days). Of 441 episodes in adult diabetic patients with cataract surgery, 90% had up to two bottles dispensed (≤60 days). Denmark had 60 403 nepafenac users (mean age, 72 years; 58% women) and 73 648 episodes (41% had recorded cataract surgery). Of 26 649 nepafenac episodes in adult non-diabetic patients with cataract surgery, 92% had one bottle dispensed. Of 3801 episodes in adult diabetic patients with cataract surgery, 99.8% had up to two bottles dispensed. Use patterns of nepafenac, ketorolac and diclofenac were roughly similar in the Netherlands, but not in Denmark. Less than half of therapy episodes were related to cataract surgery; around 90% of episodes with surgery were within the approved duration. Underrecording of ophthalmic conditions and procedures was a challenge in this study. © 2017 The Authors Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Age-related Cataract in a Randomized Trial of Vitamins E and C in Men

PubMed Central

Christen, William G.; Glynn, Robert J.; Sesso, Howard D.; Kurth, Tobias; MacFadyen, Jean; Bubes, Vadim; Buring, Julie E.; Manson, JoAnn E.; Michael Gaziano, J.

2010-01-01

Objective To test whether supplementation with alternate day vitamin E or daily vitamin C affects the incidence of age-related cataract in a large-scale randomized trial of men. Design Randomized, double-masked, placebo-controlled trial. Participants Eleven thousand five hundred forty-five apparently healthy US male physicians aged 50 years or older who were without a diagnosis of cataract at baseline. Intervention Participants were randomly assigned to receive 400 IU of vitamin E or placebo on alternate days, and 500 mg of vitamin C or placebo daily. Main Outcome Measure Incident cataract responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review. Results After 8 years of treatment and follow-up, a total of 1,174 incident cataracts were confirmed. There were 579 cataracts in the vitamin E treated group and 595 in the vitamin E placebo group (hazard ratio [HR], 0.99; 95 percent confidence interval [CI], 0.88 to 1.11). For vitamin C, there were 593 cataracts in the treated group and 581 in the placebo group (HR, 1.02; CI, 0.91 to 1.14). Conclusions In a large-scale randomized trial of US male physicians, long-term alternate day use of 400 IU of vitamin E and/or daily use of 500 mg of vitamin C had no significant beneficial or harmful effect on the risk of cataract. Application to Clinical Practice Long-term use of vitamin E and/or vitamin C supplements has no appreciable effect on cataract. PMID:21060040

Cataract, Visual Impairment and Long-Term Mortality in a Rural Cohort in India: The Andhra Pradesh Eye Disease Study

PubMed Central

Khanna, Rohit C.; Murthy, Gudlavalleti V. S.; Giridhar, Pyda; Krishnaiah, Sannapaneni; Pant, Hira B.; Palamaner Subash Shantha, Ghanshyam; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N.

2013-01-01

Background A large-scale prevalence survey of blindness and visual impairment (The Andhra Pradesh Eye Diseases Study [APEDS1]) was conducted between 1996-2000 on 10,293 individuals of all ages in three rural and one urban clusters in Andhra Pradesh, Southern India. More than a decade later (June 2009-March 2010), APEDS1 participants in rural clusters were traced (termed APEDS2) to determine ocular risk factors for mortality in this longitudinal cohort. Methods and Findings Mortality hazard ratio (HR) analysis was performed for those aged >30 years at APEDS1, using Cox proportional hazard regression models to identify associations between ocular exposures and risk of mortality. Blindness and visual impairment (VI) were defined using Indian definitions. 799/4,188 (19.1%) participants had died and 308 (7.3%) had migrated. Mortality was higher in males than females (p<0.001). In multivariable analysis, after adjusting for age, gender, diabetes, hypertension, body mass index, smoking and education status the mortality HR was 1.9 (95% CI: 1.5-2.5) for blindness; 1.4 (95% CI: 1.2-1.7) for VI; 1.8 (95% CI: 1.4-2.3) for pure nuclear cataract, 1.5 (95% CI: 1.1-2.1) for pure cortical cataract; 1.96 (95% CI: 1.6-2.4) for mixed cataract, 2.0 (95% CI: 1.4-2.9) for history of cataract surgery, and 1.58 (95% CI: 1.3-1.9) for any cataract. When all these factors were included in the model, the HRs were attenuated, being 1.5 (95% CI: 1.1-2.0) for blindness and 1.2 (95% CI: 0.9-1.5) for VI. For lens type, the HRs were as follows: pure nuclear cataract, 1.6 (95% CI: 1.3-2.1); pure cortical cataract, 1.5 (95% CI: 1.1-2.1); mixed cataract, 1.8 (95% CI: 1.4-2.2), and history of previous cataract surgery, 1.8 (95% CI: 1.3-2.6). Conclusions All types of cataract, history of cataract surgery and VI had an increased risk of mortality that further suggests that these could be potential markers of ageing. PMID:24282482

Epidemiologic study of age-related cataracts among an elderly Chinese population in Shih-Pai, Taiwan.

PubMed

Tsai, Su-Ying; Hsu, Wen-Ming; Cheng, Ching-Yu; Liu, Jorn-Hon; Chou, Pesus

2003-06-01

The purpose of this study was to determine the prevalence and risk factors for age-related cataracts in a metropolitan elderly Chinese population in Shihpai, Taipei, Taiwan. Population-based cross-sectional study. A total of 2045 subjects at least 65 years of age were invited to participate, and 1361 (66.6%) participated in the survey. An eye examination, including lens opacity grading, was conducted by ophthalmologists using the Lens Opacity Classification System III (LOCS III). A structured questionnaire was used for data collection. Interviewers also collected information on subjects' blood pressure, lifestyle (cigarette smoking and alcohol intake), medical history, and waist and hip circumferences. Subjects were defined as having age-related cataracts if there was any type of lens opacity with an LOCS III grade of more than 2 in one or both eyes. When both eyes of an individual had age-related cataracts, the more affected eye was used for analysis. Among the 1361 participants, 806 were diagnosed with age-related cataracts. The prevalence was 59.2% (95% confidence interval, 56.6%-61.8%). Women had a higher prevalence of cataracts than men (64.0% vs. 56.1%, P = 0.004). The prevalence of age-related cataracts increased with age (P = 0.001). Nuclear opacity was the most prevalent type (38.9%), followed by cortical opacity (21.9%) and posterior subcapsular opacity (9.2%). On the basis of the final logistic regression model, after controlling for all other covariates, increased age and female gender were factors that were associated with an increased risk for all types of cataracts. Besides age and gender, the most significant risk factor for nuclear cataracts was current cigarette smoking; the significant predictors for cortical cataracts were higher systolic blood pressure, a history of cigarette smoking in the past, and history of diabetes; the significant predictor for posterior subcapsular cataracts was higher systolic blood pressure. The increasing prevalence of age-related cataracts with age highlights the need to seek appropriate medical services and for preventative interventions. Elderly people often ignore the importance of seeking vision services and care to prevent blindness or visual impairment. These findings suggest that the elderly need to be educated regarding the importance of eye care by physicians and hygiene authorities in Taiwan.

Advances in pharmacological strategies for the prevention of cataract development

PubMed Central

Gupta, S K; Selvan, V Kalai; Agrawal, S S; Saxena, Rohit

2009-01-01

Cataractous-opacification of the lens is one of the leading causes of blindness in India. The situation can be managed by surgical removal of the cataractous lens. Various pharmacological strategies have been proposed for the prevention and treatment of cataract. Information on possible benefits of putative anticataract agents comes from a variety of approaches, ranging from laboratory experiments, both in vitro and in vivo, to epidemiological studies in patients. This review deals with the various mechanisms, and possible pharmacological interventions for the prevention of cataract. The article also reviews research on potential anticataractous agents, including aldose reductase inhibitors, glutathione boosters, antiglycating agents, vitamins and various drugs from indigenous sources. PMID:19384010

Cataract Surgery Tool

NASA Technical Reports Server (NTRS)

1977-01-01

The NASA-McGannon cataract surgery tool is a tiny cutter-pump which liquefies and pumps the cataract lens material from the eye. Inserted through a small incision in the cornea, the tool can be used on the hardest cataract lens. The cutter is driven by a turbine which operates at about 200,000 revolutions per minute. Incorporated in the mechanism are two passages for saline solutions, one to maintain constant pressure within the eye, the other for removal of the fragmented lens material and fluids. Three years of effort have produced a design, now being clinically evaluated, with excellent potential for improved cataract surgery. The use of this tool is expected to reduce the patient's hospital stay and recovery period significantly.

Identification of proteins in the aqueous humor associated with cataract development using iTRAQ methodology.

PubMed

Xiang, Minhong; Zhang, Xingru; Li, Qingsong; Wang, Hanmin; Zhang, Zhenyong; Han, Zhumei; Ke, Meiqing; Chen, Xingxing

2017-05-01

Proteins in the aqueous humor (AH) are important in the induction of cataract development. The identification of cataract-associated proteins assists in identifying patients and predisposed to the condition and improve treatment efficacy. Proteomics analysis has previously been used for identifying protein markers associated with eye diseases; however, few studies have examined the proteomic alterations in cataract development due to high myopia, glaucoma and diabetes. The present study, using the isobaric tagging for relative and absolute protein quantification methodology, aimed to examine cataract-associated proteins in the AH from patients with high myopia, glaucoma or diabetes, and controls. The results revealed that 445 proteins were identified in the AH groups, compared with the control groups, and 146, 264 and 130 proteins were differentially expressed in the three groups of patients, respectively. In addition, 44 of these proteins were determined to be cataract‑associated, and the alterations of five randomly selected proteins were confirmed using enzyme-linked immunosorbent assays. The biological functions of these 44 cataract-associated proteins were analyzed using Gen Ontology/pathways annotation, in addition to protein‑protein interaction network analysis. The results aimed to expand current knowledge of the pathophysiologic characteristics of cataract development and provided a panel of candidates for biomarkers of the disease, which may assist in further diagnosis and the monitoring of cataract development.

Lightless cataract surgery using a near-infrared operating microscope.

PubMed

Kim, Bong-Hyun

2006-10-01

To describe the near-infrared (NIR) operating microscopy (NIOM) system using the NIR wavelength as the illumination source and to evaluate the feasibility of this system for lightless cataract surgery. HenAm Kim Eye Center, Haenam-Gun, South Korea. In this noncomparative interventional case series, cataract surgery was performed in 4 patients with bilateral cataract using the NIOM system in 1 eye and conventional microscopy in the fellow eye. The primary components of the system include an optical filter, a stereoscopic camera, head-mounted displays, and a recording system. This system uses invisible NIR (wavelength 850 to 1300 nm) illumination to facilitate cataract surgery without light. The differences between the NIOM system and conventional microscopy during cataract surgery were evaluated. The NIOM system provided excellent 3-dimensional viewing in real time. The image resolution was sufficient while performing all steps of cataract surgery. Immediately postoperatively and at 10 and 30 minutes and 1 hour, the visual acuity was better in the 4 eyes in which the NIOM system was used than in the 4 eyes in which conventional microscopy was used. However, using the NIOM system required good surgical skill. Lightless cataract surgery using the NIOM system seems useful for obtaining good visual acuity immediately postoperatively. The system may also reduce the incidence of light-induced retinal toxicity and the need for mydriatic administration and be a good educational tool.

Task shifting for cataract surgery in eastern Africa: productivity and attrition of non-physician cataract surgeons in Kenya, Malawi and Tanzania.

PubMed

Eliah, Edson; Lewallen, Susan; Kalua, Khumbo; Courtright, Paul; Gichangi, Michael; Bassett, Ken

2014-01-01

This project examined the surgical productivity and attrition of non-physician cataract surgeons (NPCSs) in Tanzania, Malawi, and Kenya. Baseline (2008-9) data on training, support, and productivity (annual cataract surgery rate) were collected from officially trained NPCSs using mailed questionnaires followed by telephone interviews. Telephone interviews were used to collect follow-up data annually on productivity and semi-annually on attrition. A detailed telephone interview was conducted if a surgeon left his/her post. Data were entered into and analysed using STATA. Among the 135 NPCSs, 129 were enrolled in the study (Kenya 88, Tanzania 38, and Malawi 3) mean age 42 years; average time since completing training 6.6 years. Employment was in District 44%, Regional 24% or mission/ private 32% hospitals. Small incision cataract surgery was practiced by 38% of the NPCSs. The mean cataract surgery rate was 188/year, median 76 (range 0-1700). For 39 (31%) NPCSs their surgical rate was more than 200/year. Approximately 22% in Kenya and 25% in Tanzania had years where the cataract surgical rate was zero. About 11% of the surgeons had no support staff. High quality training is necessary but not sufficient to result in cataract surgical activity that meets population needs and maintains surgical skill. Needed are supporting institutions and staff, functioning equipment and programs to recruit and transport patients.

[Impact of timing of surgery on outcome in children with bilateral congenital cataract].

PubMed

Kuhli-Hattenbach, C; Fronius, M; Kohnen, T

2017-03-01

The optimal time for surgical intervention in bilateral congenital cataract is still a matter of controversy. Herein, we evaluated clinical and functional results after bilateral congenital cataract surgery and performed subgroup analysis based on the age at the time of surgery. We retrospectively reviewed the records of 52 eyes of 26 children who underwent surgery for bilateral congenital cataract without intraocular lens implantation within the first 12 months of life; 16 eyes underwent phacoaspiration within the first 10 weeks of life (group A) and 26 eyes had cataract extraction at an age of >10 weeks (group B). We defined the primary outcome measure to be the prevalence of mild, moderate, and severe amblyopia in relationship to age-dependent visual acuity norms after a mean follow-up of 59.7 ± 43.2 months. Secondary outcome measures were interocular difference of visual acuity and the presence of strabismus, nystagmus, posterior capsule opacification, and aphakic glaucoma. The prevalence of amblyopia was not statistically different between the two age groups. Of all children, 62.5 % (A) and 61.1 % (B) developed age-dependent normal visual acuity or mild amblyopia. However, the younger cohort developed significantly less strabismus than the older cohort (P = 0.03). There was a strong relationship between cataract surgery within the first 14 weeks of life and the development of aphakic glaucoma. All children developing secondary cataract formation underwent cataract surgery in the first 20 weeks of life. Our results suggest that long-term prevalence of mild, moderate, and severe amblyopia is similar between the two cohorts of bilateral congenital cataract eyes based on the age ≤ or >10 weeks at the time of surgery. Because there is a strong relationship between postoperative complications and a young age at the time of cataract surgery, close postoperative follow-up is essential. Strabismus is less likely to develop in infants after bilateral cataract surgery within the first 10 weeks of life.

Orally Active Multi-Functional Antioxidants Delay Cataract Formation in Streptozotocin (Type 1) Diabetic and Gamma-Irradiated Rats

PubMed Central

Randazzo, James; Zhang, Peng; Makita, Jun; Blessing, Karen; Kador, Peter F.

2011-01-01

Background Age-related cataract is a worldwide health care problem whose progression has been linked to oxidative stress and the accumulation of redox-active metals. Since there is no specific animal model for human age-related cataract, multiple animal models must be used to evaluate potential therapies that may delay and/or prevent cataract formation. Methods/Principal Findings Proof of concept studies were conducted to evaluate 4-(5-hydroxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4) and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8), multi-functional antioxidants that can independently chelate redox metals and quench free radicals, on their ability to delay the progression of diabetic “sugar” cataracts and gamma radiation-induced cataracts. Prior to 15 Gy of whole head irradiation, select groups of Long Evans rats received either diet containing compound 4 or 8, or a single i.p. injection of panthethine, a radioprotective agent. Compared to untreated, irradiated rats, treatment with pantethine, 4 and 8 delayed initial lens changes by 4, 47, and 38 days, respectively, and the average formation of posterior subcapsular opacities by 23, 53 and 58 days, respectively. In the second study, select groups of diabetic Sprague Dawley rats were administered chow containing compounds 4, 8 or the aldose reductase inhibitor AL1576. As anticipated, treatment with AL1576 prevented cataract by inhibiting sorbitol formation in the lens. However, compared to untreated rats, compounds 4 and 8 delayed vacuole formation by 20 days and 12 days, respectively, and cortical cataract formation by 8 and 3 days, respectively, without reducing lenticular sorbitol. Using in vitro lens culture in 30 mM xylose to model diabetic “sugar” cataract formation, western blots confirmed that multi-functional antioxidants reduced endoplasmic reticulum stress. Conclusions/Significance Multi-functional antioxidants delayed cataract formation in two diverse rat models. These studies provide a proof of concept that a general cataract treatment focused on reducing oxidative stress instead of a specific mechanism of cataractogenesis can be developed. PMID:21541328

Cataract surgery in Southern Ethiopia: distribution, rates and determinants of service provision.

PubMed

Habtamu, Esmael; Eshete, Zebiba; Burton, Matthew J

2013-11-19

Cataract is the leading cause of blindness worldwide, with the greatest burden found in low-income countries. Cataract surgery is a curative and cost-effective intervention. Despite major non-governmental organization (NGO) support, the cataract surgery performed in Southern Region, Ethiopia is currently insufficient to address the need. We analyzed the distribution, productivity, cost and determinants of cataract surgery services. Confidential interviews were conducted with all eye surgeons (Ophthalmologists & Non-Physician Cataract Surgeons [NPCS]) in Southern Region using semi-structured questionnaires. Eye care project managers were interviewed using open-ended qualitative questionnaires. All eye units were visited. Information on resources, costs, and the rates and determinants of surgical output were collected. Cataract surgery provision is uneven across Southern Region: 66% of the units are within 200 km of the regional capital. Surgeon to population ratios varied widely from 1:70,000 in the capital to no service provision in areas containing 7 million people. The Cataract Surgical Rate (CSR) in 2010 was 406 operations/million/year with zonal CSRs ranging between 204 and 1349. Average number of surgeries performed was 374 operations/surgeon/year. Ophthalmologists and NPCS performed a mean of 682 and 280 cataract operations/surgeon/year, respectively (p = 0.03). Resources are underutilized, at 56% of capacity. Community awareness programs were associated with increased activity (p = 0.009). Several factors were associated with increased surgeon productivity (p < 0.05): working for >2 years, working in a NGO/private clinic, working in an urban unit, having a unit manger, conducting outreach programs and a satisfactory work environment. The average cost of cataract surgery in 2010 was US$141.6 (Range: US$37.6-312.6). Units received >70% of their consumables from NGOs. Mangers identified poor staff motivation, community awareness and limited government support as major challenges. The uneven distribution of infrastructure and personnel, underutilization by the community and inadequate attention and support from the government are limiting cataract surgery service delivery in Southern Ethiopia. Improved human resource management and implementing community-oriented strategies may help increase surgical output and achieve the "Vision 2020: The Right to Sight" targets for treating avoidable blindness.

Self-reported cataracts in older adults in Ghana: sociodemographic and health related factors.

PubMed

Yawson, Alfred E; Ackuaku-Dogbe, Edith M; Seneadza, Nana A Hagan; Mensah, George; Minicuci, Nadia; Naidoo, Nirmala; Chatterji, Somnath; Kowal, Paul; Biritwum, Richard B

2014-09-12

Changes in function of sensory organs with increasing age have significant impact on health and wellbeing of older persons. This paper describes cataract, a chronic eye condition, self-reported among older adults in Ghana and the need for improving access to eye care services. This work was based on the World Health Organization's multi-country Study on global AGEing and adult health (SAGE), conducted in six countries including Ghana. SAGE Wave 1 in Ghana was conducted in 2007-2008 in a nationally representative sample of 4278 older adults, ≥ 50 years. Data were obtained on sociodemographic and health factors related to self-reported cataracts in older persons in Ghana. Data were analysed using descriptive measures (frequencies and proportions), chi-square test for associations in categorical outcome measures, and logistic regression for predictors of cataracts with SPSS version 21. Overall prevalence of self-reported cataracts among 4278 older adults in Ghana was 5.4%. Prevalence was proportionately higher for women (5.9%) than men (4.7%). Reported cataracts increased with age, among urban residents, in older adults living without partners and among those with the worse life satisfaction index. Older adults in lower income groups, poorly educated or living alone had difficulty seeking vision care services. Prevalence was 8.4% among persons with diabetes, 10.4% among hypertensives and 11.4% in persons with previous history of stroke. Among older persons who had ever used alcohol or tobacco, prevalence rates of reported cataracts were 5.7% and 4.9%, respectively. Logistic regression analysis indicated that increasing age, lower income status and self-reported hypertension were significantly associated with cataract among older adults in Ghana. Cataract is prevalent in older people in Ghana with approximately 1 in 20 people aged 50 years or older reporting a previous diagnosis of cataract. As cataract surgery is restorative, a public health approach on behavioural modification, well structured national outreach eye care services (for rural residents), inclusion of basic eye health services at sub-district levels, increased family support and national health insurance for older persons is indicated.

Lutein/zeaxanthin for the treatment of age-related cataract: AREDS2 randomized trial report no. 4.

PubMed

Chew, Emily Y; SanGiovanni, John Paul; Ferris, Frederick L; Wong, Wai T; Agron, Elvira; Clemons, Traci E; Sperduto, Robert; Danis, Ronald; Chandra, Suresh R; Blodi, Barbara A; Domalpally, Amitha; Elman, Michael J; Antoszyk, Andrew N; Ruby, Alan J; Orth, David; Bressler, Susan B; Fish, Gary E; Hubbard, George B; Klein, Michael L; Friberg, Thomas R; Rosenfeld, Philip J; Toth, Cynthia A; Bernstein, Paul

2013-07-01

Age-related cataract is a leading cause of visual impairment in the United States. The prevalence of age-related cataract is increasing, with an estimated 30.1 million Americans likely to be affected by 2020. To determine whether daily oral supplementation with lutein/zeaxanthin affects the risk for cataract surgery. The Age-Related Eye Disease Study 2 (AREDS2), a multicenter, double-masked clinical trial, enrolled 4203 participants, aged 50 to 85 years, at risk for progression to advanced age-related macular degeneration. Participants were randomly assigned to daily placebo; lutein/zeaxanthin, 10mg/2mg; omega-3 long-chain polyunsaturated fatty acids, 1 g; or a combination to evaluate the effects on the primary outcome of progression to advanced age-related macular degeneration. Cataract surgery was documented at annual study examination with the presence of pseudophakia or aphakia, or reported during telephone calls at 6-month intervals between study visits. Annual best-corrected visual acuity testing was performed. A secondary outcome of AREDS2 was to evaluate the effects of lutein/zeaxanthin on the subsequent need for cataract surgery. A total of 3159 AREDS2 participants were phakic in at least 1 eye and 1389 of 6027 study eyes underwent cataract surgery during the study, with median follow-up of 4.7 years. The 5-year probability of progression to cataract surgery in the no lutein/zeaxanthin group was 24%. For lutein/zeaxanthin vs no lutein/zeaxanthin, the hazard ratios for progression to cataract surgery was 0.96 (95% CI, 0.84-1.10; P = .54). For participants in the lowest quintile of dietary intake of lutein/zeaxanthin, the hazard ratio comparing lutein/zeaxanthin vs no lutein/zeaxanthin for progression to cataract surgery was 0.68 (95% CI, 0.48-0.96; P = .03). The hazard ratio for 3 or more lines of vision loss was 1.03 (95% CI, 0.93-1.13; P = .61 for lutein/zeaxanthin vs no lutein/zeaxanthin). Daily supplementation with lutein/zeaxanthin had no statistically significant overall effect on rates of cataract surgery or vision loss. clinicaltrials.gov Identifier: NCT00345176.

Thioredoxin, thioredoxin reductase, and alpha-crystallin revive inactivated glyceraldehyde 3-phosphate dehydrogenase in human aged and cataract lens extracts.

PubMed

Yan, Hong; Lou, Marjorie F; Fernando, M Rohan; Harding, John J

2006-10-02

To investigate whether mammalian thioredoxin (Trx) and thioredoxin reductase (TrxR), with or without alpha-crystallin can revive inactivated glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in both the cortex and nucleus of human aged clear and cataract lenses. The lens cortex (including capsule-epithelium) and the nucleus were separated from human aged clear and cataract lenses (grade II and grade IV) with similar average age. The activity of GAPDH in the water-soluble fraction after incubation with or without Trx or/and TrxR for 60 min at 30 degrees C was measured spectrophotometrically. In addition, the effect of a combination of Trx/TrxR and bovine lens alpha-crystallin was investigated. GAPDH activity was lower in the nucleus of clear lenses than in the cortex, and considerably diminished in the cataractous lenses, particularly in the nucleus of cataract lenses grade IV. Trx and TrxR were able to revive the activity of GAPDH markedly in both the cortex and nucleus of the clear and cataract lenses. The percentage increase of activity in the cortex of the clear lenses was less than that of the nucleus in the presence of Trx and TrxR, whereas it was opposite in the cataract lenses. The revival of activity in both the cortex and nucleus from the cataract lenses grade II was higher than that of the grade IV. Moreover, Trx alone, but not TrxR, efficiently enhanced GAPDH activity. The combination of Trx and TrxR had greater effect than that of either alone. In addition, alpha(L)-crystallin enhanced the activity in the cortex of cataract grade II with Trx and TrxR present. However, it failed to provide a statistically significant increase of activity in the nucleus. This is the first evidence to show that mammalian Trx and TrxR are able to revive inactivated GAPDH in human aged clear and cataract lenses, and alpha-crystallin helped this effect. The inactivation of GAPDH during aging and cataract development must be caused in part by disulphide formation and in part by unfolding, and can be recovered by reducing agents and a molecular chaperone.

Age-related Cataract in a Randomized Trial of Selenium and Vitamin E in Men: The SELECT Eye Endpoints (SEE) Study

PubMed Central

Christen, William G.; Glynn, Robert J.; Gaziano, J. Michael; Darke, Amy K.; Crowley, John J.; Goodman, Phyllis J.; Lippman, Scott M.; Lad, Thomas E.; Bearden, James D.; Goodman, Gary E.; Minasian, Lori M.; Thompson, Ian M.; Blanke, Charles D.; Klein, Eric A.

2014-01-01

Importance Observational studies suggest a role for dietary nutrients such as vitamin E and selenium in cataract prevention. However, the results of randomized trials of vitamin E supplements and cataract have been disappointing, and are not yet available for selenium. Objective To test whether long-term supplementation with selenium and vitamin E affects the incidence of cataract in a large cohort of men. Design, Setting, and Participants The SELECT Eye Endpoints (SEE) study was an ancillary study of the SWOG-coordinated Selenium and Vitamin E Cancer Prevention Trial (SELECT), a randomized, placebo-controlled, four arm trial of selenium and vitamin E conducted among 35,533 men aged 50 years and older for African Americans and 55 and older for all other men, at 427 participating sites in the US, Canada, and Puerto Rico. A total of 11,267 SELECT participants from 128 SELECT sites participated in the SEE ancillary study. Intervention Individual supplements of selenium (200 µg/d from L-selenomethionine) and vitamin E (400 IU/d of all rac-α-tocopheryl acetate). Main Outcome Measures Incident cataract, defined as a lens opacity, age-related in origin, responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review, and cataract extraction, defined as the surgical removal of an incident cataract. Results During a mean (SD) of 5.6 (1.2) years of treatment and follow-up, 389 cases of cataract were documented. There were 185 cataracts in the selenium group and 204 in the no selenium group (hazard ratio [HR], 0.91; 95 percent confidence interval [CI], 0.75 to 1.11; P=.37). For vitamin E, there were 197 cases in the treated group and 192 in the placebo group (HR, 1.02; CI, 0.84 to 1.25; P=.81). Similar results were observed for cataract extraction. Conclusions and Relevance These randomized trial data from a large cohort of apparently healthy men indicate that long-term daily supplementation with selenium and/or vitamin E is unlikely to have a large beneficial effect on age-related cataract. PMID:25232809

Is current eye-care-policy focus almost exclusively on cataract adequate to deal with blindness in India?

PubMed

Dandona, L; Dandona, R; Naduvilath, T J; McCarty, C A; Nanda, A; Srinivas, M; Mandal, P; Rao, G N

1998-05-02

India's National Programme for Control of Blindness focuses almost exclusively on cataract, based on a national survey done in the 1980s which reported that cataract caused 80% of the blindness in India. No current population-based data on the causes of blindness in India are available. We assessed the rate and causes of blindness in an urban population in southern India. We selected 2954 participants by stratified, random, cluster, systematic sampling from Hyderabad city. Eligible participants were interviewed and given a detailed ocular assessment, including visual acuity, refraction, slitlamp biomicroscopy, applanation intraocular pressure, gonioscopy, dilatation, grading of cataract, stereoscopic fundus assessment, and automated-threshold visual fields. 2522 participants, including 1399 aged 30 years or more, were assessed. 49 participants (all aged > or =30 years) were blind (presenting distance visual acuity <6/60 or central visual field <200 in the better eye). The rate of blindness among those aged 30 years or more, adjusted for age and sex, was 3.08% ([95% CI 1.95-4.21]). Causes included cataract (29.7%), retinal disease (17.1%), corneal disease (15.4%), refractive error (12.5%), glaucoma (12.1%), and optic atrophy (11.0%). 15.7% of the blindness caused by visual-field constriction would have been missed without visual-field examination. Also without visual-field and detailed dilated-fundus assessments, blindness attributed to cataract would have been overestimated by up to 75.8%. If the use of cataract surgery in this urban population was half that found in this study, which simulates the situation in rural India, cataract would have caused 51.8% (39.4-64.2) of blindness, significantly less than the 80% accepted by current policy. Much of the blindness in this Indian population was due to non-cataract causes. The previous national survey did not include detailed dilated-fundus assessment and visual-field examination which could have led to overestimation of cataract as a cause of blindness in India. Policy-makers in India should encourage well-designed population-based epidemiological studies from which to develop a comprehensive long-term policy on blindness in addition to dealing with cataract.

Non-destructive analysis of the conformational changes in human lens lipid and protein structures of the immature cataracts associated with glaucoma

NASA Astrophysics Data System (ADS)

Lin, Shan-Yang; Li, Mei-Jane; Liang, Run-Chu; Lee, Shui-Mei

1998-09-01

Previous study has supposed a possible mechanism of exacerbating cataract formation in cataractous human lens capsules induced by hypertension or glaucoma. To clarify the glaucoma-induced cataract formation of the eyes lens, changes in the human lens lipid and protein structures of immature cataractous patients with or without glaucoma were investigated. Two normal lenses, ten immature cataractous lenses without any complication and four immature cataractous lenses with glaucoma were used after surgical operation. Each de-capsulated human lens sample was sliced with a number 15 surgical blade. The intact nuclear lens regions were used for non-destructive analysis. The lens lipid and protein structures, as well as compositions of these lens samples, were determined using a Fourier transform infrared (FTIR) microspectroscopy with second-derivative, de-convolution and curve-fitting methods. The results indicate that the IR spectrum of glaucomatous lenses appeared as a shoulder only at 2853 cm -1, thus the composition of the symmetric CH 2 stretching band at 2853 (2852) cm -1 decreased more significantly in glaucomatous lens to only one half of that in normal and immature cataractous lenses. The composition of the asymmetric CH 3 stretching band at 2965 cm -1 for normal lens decreases markedly from 32 to 20% for immature cataractous lenses with or without glaucoma. The compositional ratio of component at 2965 cm -1 to component at 2928 (2930) cm -1 for normal lenses was about 0.702, and that ratio for cataractous lenses without glaucoma was 0.382 but for glaucomatous lenses was 0.377. The maximum peak position of amide I band for IR spectra of the normal lens, immature cataractous lenses without complications or glaucomatous lenses appeared respectively at 1632, 1630 or 1622 cm -1, assigned to β sheet structure. A marked difference in peak intensity of amide I band for the normal lenses and immature cataractous human lenses with or without glaucoma was observed. The peak intensity ratio of amide I /amide II (1632/1545 cm -1) for normal lenses was in the range of 2.20-2.33, whereas in the spectra of immature cataractous lenses without glaucoma this ratio (1630/1545 cm -1) was 1.28-1.41 but was 1.04-1.13 for glaucomatous lens in the intensity ratio of 1622/1545 cm -1. The intensity of the glycogen bands in the wavenumber region 1135-1076 and 1069-1032 cm -1 was found to increase for the immature cataractous lenses with or without glaucoma, as compared with the normal ones. The peaks ranging from 1633 to 1610 cm -1 assigned to β-sheet structure also exhibited a pronounced compositional difference, particularly in glaucomatous lenses. The human lens lipid and protein secondary structures were more affected by glaucoma. Higher protein side chains and reduced lipid content contributed predominantly to the CH stretching vibrations of normal lens structure, whereas high lipid content and less protein side chains dominated the CH stretching vibrations of cataractous lenses with or without glaucoma. Decrease α-helix and random coil structures but enhanced β-sheet structure in the immature cataractous human lens induced by glaucoma might result from the formation of intermolecular hydrogen-bonding insoluble protein aggregates that modify the secondary structure of protein in lenses.

Predictors of attendance and barriers to cataract surgery in Kenya, Bangladesh and the Philippines.

PubMed

Syed, Alishbah; Polack, Sarah; Eusebio, Cristina; Mathenge, Wanjiku; Wadud, Zakia; Mamunur, A K M; Foster, Allen; Kuper, Hannah

2013-09-01

Cataract is the leading cause of blindness worldwide, and is particularly common in low- and middle-income countries. Our study aims to identify the predictors for and barriers to acceptance of cataract surgery in Kenya, Bangladesh and the Philippines. Cases were individuals aged ≥50 years and with best corrected VA of <6/24 in the better eye due to cataract who were identified through population-based surveys and community-based case detection. Cases were asked why they had not attended for surgery. They were offered free cataract surgery and followed-up at one year. Non-acceptors were interviewed to identify barriers to accepting surgery. Of all participants, 58.6% attended for cataract surgery in Kenya, 53.9% Bangladesh and 47.1% the Philippines. Younger age was a predictor for attendance for surgery in all three countries. In Bangladesh and Kenya, male gender and psychosocial score were predictors. At baseline "cost" and "unaware of cataract" were most frequently reported barriers to uptake of surgery in the three settings. At follow-up, "surgical services inaccessible" was one of the two most frequently reported barriers in Kenya and the Philippines while "fear" was most frequently reported in Bangladesh and the Philippines. There were no consistent predictors of the most frequently reported barriers across the different settings. Future services need to focus on increasing uptake among older people and women. Cost is often reported as a barrier but this may conceal more complicated underlying barriers which need to be explored through in-depth qualitative research. Cataract is the leading cause of blindness worldwide, and is particularly common in low- and middle-income countries. Evidence suggests that even when surgical services are available, there can be a lack of demand and low utilization resulting from barriers to uptake. Older cataract patients, females and especially older females are least likely to attend for surgery. Future cataract surgical programmes should put special emphasis on targeting and increasing uptake in these groups.

The changing pattern of cataract surgery indications: a 5-year study of 2 cataract surgery databases.

PubMed

Lundström, Mats; Goh, Pik-Pin; Henry, Ype; Salowi, Mohamad A; Barry, Peter; Manning, Sonia; Rosen, Paul; Stenevi, Ulf

2015-01-01

The aim of this study was to describe changes over time in the indications and outcomes of cataract surgery and to discuss optimal timing for the surgery. Database study. Patients who had undergone cataract extraction in the Netherlands, Sweden, or Malaysia from 2008 through 2012. We analyzed preoperative, surgical, and postoperative data from 2 databases: the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) and the Malaysian National Cataract Registry. The EUREQUO contains complete data from the national cataract registries in the Netherlands and Sweden. Preoperative and postoperative corrected distance visual acuity, preoperative ocular comorbidity in the surgery eye, and capsule complications during surgery. There were substantial differences in indication for surgery between the 3 national data sets. The percentage of eyes with a preoperative best-corrected visual acuity of 20/200 or worse varied from 7.1% to 72%. In all 3 data sets, the visual thresholds for cataract surgery decreased over time by 6% to 28% of the baseline values. The frequency of capsule complications varied between the 3 data sets, from 1.1% to 3.7% in 2008 and from 0.6% to 2.7% in 2012. An increasing postoperative visual acuity was also seen for all 3 data sets. A high frequency of capsule complication was related significantly to poor preoperative visual acuity, and a high frequency of decreased visual acuity after surgery was related significantly to excellent preoperative visual acuity. The 5-year trend in all 3 national data sets showed decreasing visual thresholds for surgery, decreasing surgical complication rates, and increasing visual outcomes regardless of the initial preoperative visual level. Cataract surgery on eyes with poor preoperative visual acuity was related to surgical complications, and cataract surgery on eyes with excellent preoperative visual acuity was related to adverse visual results. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Pediatric cataract surgery in Madagascar.

PubMed

Randrianotahina, H C L; Nkumbe, H E

2014-01-01

Cataract is the main cause of blindness among children in Africa, having replaced vitamin A deficiency and measles. The management of childhood cataract in Africa, especially francophone countries, is inadequate. The objective is to study the age at presentation of children diagnosed with cataract, their visual outcomes, and follow-up patterns after surgery in Madagascar. This was a retrospective case series of children operated on for cataract in one of the busiest eye hospitals in Madagascar between September 1999 and July 2009. Data were obtained from theater logs and patient case notes and entered in a Microsoft Excel spreadsheet. Data entry was carried out using Microsoft Excel and analysis using Intercooled Stata version 9.0. Student t-test and Pearson's Chi-square were used to test associations where appropriate. A total of 60.5 percent of the 86 children operated on during the study period were boys. The mean age at presentation was 6.9 years (±SD 4.3) for congenital cataract, 13.1 years (±SD 2.9) for developmental cataract and 9.4 years (±SD 4.0) for traumatic cataract. A total of 36 children (41.9%) came back for follow-up, while 72 children (83.7%) were lost to follow-up 5 weeks after surgery. The mean follow-up period was 5 weeks (±SD 17.9). Children, who were brought back for follow-up were younger than those who were not. Although 64 (74.4%) of children had refraction during their encounters with the eye care facility, only 3 (3.5%) were provided with glasses. At last documented follow-up, 2.7% of the children had 6/18 vision or better. In Madagascar, presentation for congenital and developmental cataract is very late, visual outcome poor and follow-up inadequate. There is an urgent need for a childhood blindness program to effectively deal with pediatric cataract, an avoidable cause of blindness and visual disability in children on the island nation.

Germ-line and somatic EPHA2 coding variants in lens aging and cataract.

PubMed

Bennett, Thomas M; M'Hamdi, Oussama; Hejtmancik, J Fielding; Shiels, Alan

2017-01-01

Rare germ-line mutations in the coding regions of the human EPHA2 gene (EPHA2) have been associated with inherited forms of pediatric cataract, whereas, frequent, non-coding, single nucleotide variants (SNVs) have been associated with age-related cataract. Here we sought to determine if germ-line EPHA2 coding SNVs were associated with age-related cataract in a case-control DNA panel (> 50 years) and if somatic EPHA2 coding SNVs were associated with lens aging and/or cataract in a post-mortem lens DNA panel (> 48 years). Micro-fluidic PCR amplification followed by targeted amplicon (exon) next-generation (deep) sequencing of EPHA2 (17-exons) afforded high read-depth coverage (1000x) for > 82% of reads in the cataract case-control panel (161 cases, 64 controls) and > 70% of reads in the post-mortem lens panel (35 clear lens pairs, 22 cataract lens pairs). Novel and reference (known) missense SNVs in EPHA2 that were predicted in silico to be functionally damaging were found in both cases and controls from the age-related cataract panel at variant allele frequencies (VAFs) consistent with germ-line transmission (VAF > 20%). Similarly, both novel and reference missense SNVs in EPHA2 were found in the post-mortem lens panel at VAFs consistent with a somatic origin (VAF > 3%). The majority of SNVs found in the cataract case-control panel and post-mortem lens panel were transitions and many occurred at di-pyrimidine sites that are susceptible to ultraviolet (UV) radiation induced mutation. These data suggest that novel germ-line (blood) and somatic (lens) coding SNVs in EPHA2 that are predicted to be functionally deleterious occur in adults over 50 years of age. However, both types of EPHA2 coding variants were present at comparable levels in individuals with or without age-related cataract making simple genotype-phenotype correlations inconclusive.

Germ-line and somatic EPHA2 coding variants in lens aging and cataract

PubMed Central

Bennett, Thomas M.; M’Hamdi, Oussama; Hejtmancik, J. Fielding

2017-01-01

Rare germ-line mutations in the coding regions of the human EPHA2 gene (EPHA2) have been associated with inherited forms of pediatric cataract, whereas, frequent, non-coding, single nucleotide variants (SNVs) have been associated with age-related cataract. Here we sought to determine if germ-line EPHA2 coding SNVs were associated with age-related cataract in a case-control DNA panel (> 50 years) and if somatic EPHA2 coding SNVs were associated with lens aging and/or cataract in a post-mortem lens DNA panel (> 48 years). Micro-fluidic PCR amplification followed by targeted amplicon (exon) next-generation (deep) sequencing of EPHA2 (17-exons) afforded high read-depth coverage (1000x) for > 82% of reads in the cataract case-control panel (161 cases, 64 controls) and > 70% of reads in the post-mortem lens panel (35 clear lens pairs, 22 cataract lens pairs). Novel and reference (known) missense SNVs in EPHA2 that were predicted in silico to be functionally damaging were found in both cases and controls from the age-related cataract panel at variant allele frequencies (VAFs) consistent with germ-line transmission (VAF > 20%). Similarly, both novel and reference missense SNVs in EPHA2 were found in the post-mortem lens panel at VAFs consistent with a somatic origin (VAF > 3%). The majority of SNVs found in the cataract case-control panel and post-mortem lens panel were transitions and many occurred at di-pyrimidine sites that are susceptible to ultraviolet (UV) radiation induced mutation. These data suggest that novel germ-line (blood) and somatic (lens) coding SNVs in EPHA2 that are predicted to be functionally deleterious occur in adults over 50 years of age. However, both types of EPHA2 coding variants were present at comparable levels in individuals with or without age-related cataract making simple genotype-phenotype correlations inconclusive. PMID:29267365

Association of Dietary Vitamin K1 Intake With the Incidence of Cataract Surgery in an Adult Mediterranean Population: A Secondary Analysis of a Randomized Clinical Trial.

PubMed

Camacho-Barcia, María L; Bulló, Mònica; Garcia-Gavilán, Jesús F; Ruiz-Canela, Miguel; Corella, Dolores; Estruch, Ramón; Fitó, Montserrat; García-Layana, Alfredo; Arós, Fernando; Fiol, Miquel; Lapetra, José; Serra-Majem, Lluis; Pintó, Xavier; García-Arellano, Ana; Vinyoles, Ernest; Sorli, José Vicente; Salas-Salvadó, Jordi

2017-06-01

Cataract, one of the most frequent causes of blindness in developed countries, is strongly associated with aging. The exact mechanisms underlying cataract formation are still unclear, but growing evidence suggests a potential role of inflammatory and oxidative processes. Therefore, antioxidant and anti-inflammatory factors of the diet, such as vitamin K1, could play a protective role. To examine the association between dietary vitamin K1 intake and the risk of incident cataracts in an elderly Mediterranean population. A prospective analysis was conducted in 5860 participants from the Prevención con Dieta Mediterránea Study, a randomized clinical trial executed between 2003 and 2011. Participants were community-dwelling men (44.2%) and women (55.8%), and the mean (SD) age was 66.3 (6.1) years. Dietary vitamin K1 intake was evaluated using a validated food frequency questionnaire. The time to the cataract event was calculated as the time between recruitment and the date of the occurrence to cataract surgery, the time to the last visit of the follow-up, date of death, or the end of the study. Hazard ratios and 95% CIs for cataract incidence were estimated with a multivariable Cox proportional hazards model. Participants were community-dwelling men (44.2%; n = 868) and women (55.8%; n = 1086), and the mean (SD) age was 66.3 (6.1) years. After a median of 5.6 years follow-up, we documented a total of 768 new cataracts. Participants in the highest tertile of dietary vitamin K1 intake had a lower risk of cataracts than those in the lowest tertile (hazard ratio, 0.71; 95% CI, 0.58-0.88; P = .002), after adjusting for potential confounders. High intake of dietary vitamin K1 was associated with a reduced risk of cataracts in an elderly Mediterranean population even after adjusting by other potential confounders. isrctn.org: ISRCTN35739639.

Parity and the risk of cataract: a cross-sectional analysis in the Dongfeng-Tongji cohort study.

PubMed

Tian, Yaohua; Wu, Jing; Xu, Guiqiang; Shen, Lijun; Yang, Siyi; Mandiwa, Chrispin; Yang, Handong; Liang, Yuan; Wang, Youjie

2015-12-01

Epidemiological evidence showed that prevalence rates of cataract were higher in women than in men. Female reproductive factors were hypothesised to be linked with this sex difference. In this study, we explored possible effects of parity and reproductive factors on the risk of cataract. Women (14 337 total; aged 45-86 years) were recruited from the Dongfeng-Tongji cohort study. All subjects completed baseline questionnaires and medical examinations and provided baseline blood samples. Cataract was diagnosed by the ophthalmologist in the ocular examination. Logistic regression models were used to evaluate the association between parity and the risk of cataract. The prevalence rate of cataract in the study population was 6.8% (972/14 337). After adjustment for potential confounders, women who had undergone two, three, and four or more live births had 1.52 times (95% CI 1.13 to 2.04), 1.67 times (95% CI 1.27 to 2.29) and 1.72 times (95% CI 1.22 to 2.42), respectively, higher risk of cataract compared with women who had undergone one live birth. The risk increased by an estimated 11.3% for each additional live birth. Women who had undergone hormone replacement therapy (OR 1.61; 95% CI 1.05 to 2.47), had diabetes mellitus (OR 1.33; 95% CI 1.11 to 1.58) and/or had the habit of drinking alcohol (OR 1.51; 95% CI 1.08 to 2.10) had a higher risk of cataract. Neither menopause status nor history of contraceptive use was associated with cataract. The findings suggested that parity was an independent risk factor for the development of cataract in Chinese women. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Prevalence and causes of blindness, visual impairment, and cataract surgery in Timor-Leste

PubMed Central

Correia, Marcelino; Das, Taraprasad; Magno, Julia; Pereira, Bernadette M; Andrade, Valerio; Limburg, Hans; Trevelyan, John; Keeffe, Jill; Verma, Nitin; Sapkota, Yuddha

2017-01-01

Purpose To estimate the prevalence and causes of blindness and visual impairment, cataract surgical coverage (CSC), visual outcome of cataract surgery, and barriers to uptake cataract surgery in Timor-Leste. Method In a nationwide rapid assessment of avoidable blindness (RAAB), the latest population (1,066,409) and household data were used to create a sampling frame which consists of 2,227 population units (study clusters) from all 13 districts, with populations of 450–900 per unit. The sample size of 3,350 was calculated with the assumed prevalence of blindness at 4.5% among people aged ≥50 years with a 20% tolerable error, 95% CI, and a 90% response rate. The team was trained in the survey methodology, and inter-observer variation was measured. Door-to-door visits, led by an ophthalmologist, were made in preselected study clusters, and data were collected in line with the RAAB5 survey protocol. An Android smart phone installed with mRAAB software was used for data collection. Result The age–gender standardized prevalence of blindness, severe visual impairment, and visual impairment were 2.8%, (1.8–3.8), 1.7% (1.7–2.3), and 8.1% (6.6–9.6), respectively. Cataract was the leading cause of blindness (79.4%). Blindness was more prevalent in the older age group and in women. CSC was 41.5% in cataract blind eyes and 48.6% in cataract blind people. Good visual outcome in the cataract-operated eyes was 62% (presenting) and 75.2% (best corrected). Two important barriers to not using available cataract surgical services were accessibility (45.5%) and lack of attendants to accompany (24.8%). Conclusion The prevalence of blindness and visual impairment in Timor-Leste remains high. CSC is unacceptably low; gender inequity in blindness and CSC exists. Lack of access is the prominent barrier to cataract surgery. PMID:29238161

Changes of visual-field global indices after cataract surgery in primary open-angle glaucoma patients.

PubMed

Seol, Bo Ram; Jeoung, Jin Wook; Park, Ki Ho

2016-11-01

To determine changes of visual-field (VF) global indices after cataract surgery and the factors associated with the effect of cataracts on those indices in primary open-angle glaucoma (POAG) patients. A retrospective chart review of 60 POAG patients who had undergone phacoemulsification and intraocular lens insertion was conducted. All of the patients were evaluated with standard automated perimetry (SAP; 30-2 Swedish interactive threshold algorithm; Carl Zeiss Meditec Inc.) before and after surgery. VF global indices before surgery were compared with those after surgery. The best-corrected visual acuity, intraocular pressure (IOP), number of glaucoma medications before surgery, mean total deviation (TD) values, mean pattern deviation (PD) value, and mean TD-PD value were also compared with the corresponding postoperative values. Additionally, postoperative peak IOP and mean IOP were evaluated. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with the effect of cataract on global indices. Mean deviation (MD) after cataract surgery was significantly improved compared with the preoperative MD. Pattern standard deviation (PSD) and visual-field index (VFI) after surgery were similar to those before surgery. Also, mean TD and mean TD-PD were significantly improved after surgery. The posterior subcapsular cataract (PSC) type showed greater MD changes than did the non-PSC type in both the univariate and multivariate logistic regression analyses. In the univariate logistic regression analysis, the preoperative TD-PD value and type of cataract were associated with MD change. However, in the multivariate logistic regression analysis, type of cataract was the only associated factor. None of the other factors was associated with MD change. MD was significantly affected by cataracts, whereas PSD and VFI were not. Most notably, the PSC type showed better MD improvement compared with the non-PSC type after cataract surgery. Clinicians therefore should carefully analyze VF examination results for POAG patients with the PSC type.

Activation of sorbitol pathway in metabolic syndrome and increased susceptibility to cataract in Wistar-Obese rats

PubMed Central

Giridharan, Nappan Veettil

2012-01-01

Purpose Obesity is a major public health problem worldwide, and of late, epidemiological studies indicate a preponderance of cataracts under obesity conditions. Although cataract is a multifactorial disorder and various biochemical mechanisms have been proposed, the influence of obesity on cataractogenesis has yet to be investigated. In such a scenario, a suitable animal model that develops cataract following the onset of obesity will be a welcome tool for biomedical research. Therefore, we investigated the molecular and biochemical basis for predisposition to cataract in the obese mutant rat models established in our institute because 15%–20% of these rats develop cataracts spontaneously as they reach 12–15 months of age. Methods We analyzed the major biochemical pathways in the normal lenses of different age groups of our obese mutant rat strains, Wistar/Obese (WNIN/Ob) and WNIN/GR-Ob, the former with euglycemia and the latter with an additional impaired glucose tolerance trait. In addition, sorbitol levels were estimated in the cataractous lenses of the obese rats. Results Except for the polyol pathway, all the principal pathways of the lens remained unaltered. Therefore, sorbitol levels were found to be high in the normal eye lenses of obese rats (WNIN/Ob and WNIN/GR-Ob) compared to their lean controls from three months of age onwards. Between WNIN/Ob and WNIN/GR-Ob, the levels of sorbitol were higher in the latter, suggesting a synergistic effect of impaired glucose tolerance along with obesity in the activation of the sorbitol pathway. Either way, an elevated sorbitol pathway seemed to be the predisposing factor responsible for cataract formation in these mutant rats. Conclusions Activation of the sorbitol pathway indeed enhances the risk of cataract development in conditions such as metabolic syndrome. These rat models thus may be valuable tools for investigating obesity-associated cataract and for developing intervention strategies, based on these findings. PMID:22393276

Activation of sorbitol pathway in metabolic syndrome and increased susceptibility to cataract in Wistar-Obese rats.

PubMed

Reddy, Paduru Yadagiri; Giridharan, Nappan Veettil; Reddy, Geereddy Bhanuprakash

2012-01-01

Obesity is a major public health problem worldwide, and of late, epidemiological studies indicate a preponderance of cataracts under obesity conditions. Although cataract is a multifactorial disorder and various biochemical mechanisms have been proposed, the influence of obesity on cataractogenesis has yet to be investigated. In such a scenario, a suitable animal model that develops cataract following the onset of obesity will be a welcome tool for biomedical research. Therefore, we investigated the molecular and biochemical basis for predisposition to cataract in the obese mutant rat models established in our institute because 15%-20% of these rats develop cataracts spontaneously as they reach 12-15 months of age. We analyzed the major biochemical pathways in the normal lenses of different age groups of our obese mutant rat strains, Wistar/Obese (WNIN/Ob) and WNIN/GR-Ob, the former with euglycemia and the latter with an additional impaired glucose tolerance trait. In addition, sorbitol levels were estimated in the cataractous lenses of the obese rats. Except for the polyol pathway, all the principal pathways of the lens remained unaltered. Therefore, sorbitol levels were found to be high in the normal eye lenses of obese rats (WNIN/Ob and WNIN/GR-Ob) compared to their lean controls from three months of age onwards. Between WNIN/Ob and WNIN/GR-Ob, the levels of sorbitol were higher in the latter, suggesting a synergistic effect of impaired glucose tolerance along with obesity in the activation of the sorbitol pathway. Either way, an elevated sorbitol pathway seemed to be the predisposing factor responsible for cataract formation in these mutant rats. Activation of the sorbitol pathway indeed enhances the risk of cataract development in conditions such as metabolic syndrome. These rat models thus may be valuable tools for investigating obesity-associated cataract and for developing intervention strategies, based on these findings.

Associations among cataract prevalence, sunlight hours, and altitude in the Himalayas.

PubMed

Brilliant, L B; Grasset, N C; Pokhrel, R P; Kolstad, A; Lepkowski, J M; Brilliant, G E; Hawks, W N; Pararajasegaram, R

1983-08-01

The relationship between cataract prevalence, altitude, and sunlight hours was investigated in a large national probability sample survey of 105 sites in the Himalayan kingdom of Nepal, December 1980 through April 1981. Cataract of senile or unknown etiology was diagnosed by ophthalmologists in 873 of 30,565 full-time life-long residents of survey sites. Simultaneously, the altitude of sites was measured using a standard mountain altimeter. Seasonally adjusted average daily duration of sunlight exposure for each site was calculated by a method which took into account latitude and obstructions along the skyline. Age- and sex-standardized cataract prevalence was 2.7 times higher in sites at an altitude of 185 meters or less than in sites over 1000 meters. Cataract prevalence was negatively correlated with altitude (r = -0.533, p less than 0.0001). However, a positive correlation between cataract prevalence and sunlight was observed (r = 0.563, p less than 0.0001). Sites with an average of 12 hours of sunlight exposure had 3.8 times as much cataract as sites with an average of only seven hours of exposure. Sunlight was blocked from reaching certain high altitude sites by tall neighboring mountains.

A VidEo-Based Intelligent Recognition and Decision System for the Phacoemulsification Cataract Surgery.

PubMed

Tian, Shu; Yin, Xu-Cheng; Wang, Zhi-Bin; Zhou, Fang; Hao, Hong-Wei

2015-01-01

The phacoemulsification surgery is one of the most advanced surgeries to treat cataract. However, the conventional surgeries are always with low automatic level of operation and over reliance on the ability of surgeons. Alternatively, one imaginative scene is to use video processing and pattern recognition technologies to automatically detect the cataract grade and intelligently control the release of the ultrasonic energy while operating. Unlike cataract grading in the diagnosis system with static images, complicated background, unexpected noise, and varied information are always introduced in dynamic videos of the surgery. Here we develop a Video-Based Intelligent Recognitionand Decision (VeBIRD) system, which breaks new ground by providing a generic framework for automatically tracking the operation process and classifying the cataract grade in microscope videos of the phacoemulsification cataract surgery. VeBIRD comprises a robust eye (iris) detector with randomized Hough transform to precisely locate the eye in the noise background, an effective probe tracker with Tracking-Learning-Detection to thereafter track the operation probe in the dynamic process, and an intelligent decider with discriminative learning to finally recognize the cataract grade in the complicated video. Experiments with a variety of real microscope videos of phacoemulsification verify VeBIRD's effectiveness.

A VidEo-Based Intelligent Recognition and Decision System for the Phacoemulsification Cataract Surgery

PubMed Central

Yin, Xu-Cheng; Wang, Zhi-Bin; Zhou, Fang; Hao, Hong-Wei

2015-01-01

The phacoemulsification surgery is one of the most advanced surgeries to treat cataract. However, the conventional surgeries are always with low automatic level of operation and over reliance on the ability of surgeons. Alternatively, one imaginative scene is to use video processing and pattern recognition technologies to automatically detect the cataract grade and intelligently control the release of the ultrasonic energy while operating. Unlike cataract grading in the diagnosis system with static images, complicated background, unexpected noise, and varied information are always introduced in dynamic videos of the surgery. Here we develop a Video-Based Intelligent Recognitionand Decision (VeBIRD) system, which breaks new ground by providing a generic framework for automatically tracking the operation process and classifying the cataract grade in microscope videos of the phacoemulsification cataract surgery. VeBIRD comprises a robust eye (iris) detector with randomized Hough transform to precisely locate the eye in the noise background, an effective probe tracker with Tracking-Learning-Detection to thereafter track the operation probe in the dynamic process, and an intelligent decider with discriminative learning to finally recognize the cataract grade in the complicated video. Experiments with a variety of real microscope videos of phacoemulsification verify VeBIRD's effectiveness. PMID:26693249

Comparison of distance and near visual acuity in patients with vision loss due to cataract.

PubMed

Mercado, Carmel L; Doroslovački, Pavle; Wang, Jiangxia; Siddiqui, Aazim A; Kolker, Andrew F; Kolker, Richard J

2017-02-01

The purpose of this study was to assess whether there is a disparity in distance and near best-corrected visual acuity (BCVA) in cataract eyes. 102 patients with cataract (N = 121 eyes) were seen in clinic between January and November 2013 at the Wilmer Eye Institute Comprehensive Eye Service. An age-related macular degeneration (ARMD) group (N = 27 eyes) was also identified for comparison. Distance and near BCVA were measured as part of the standard ophthalmic evaluation. Snellen measurements were converted to their LogMAR equivalents for statistical analysis. Near was better than distance BCVA with mean difference of 1.38 lines (P < 0.001) in the cataract eyes. This disparity was not seen in the ARMD eyes. Near-distance BCVA disparity is a statistically significant finding seen with cataracts. This may have further implications in patients with both cataract and ARMD as the presence of disparity may suggest a cataract etiology playing a greater role in vision loss. This comparison may be useful for surgical prognostication and as a quick triage tool in conjunction with, or in place of, a potential acuity meter and dilated near-pinhole test.

Manual small incision extracapsular cataract surgery in Australia.

PubMed

van Zyl, Lourens; Kahawita, Shyalle; Goggin, Michael

2014-11-01

Examination of the results and describing the technique of manual small incision extracapsular cataract extraction on patients with advanced cataracts in urban Australia. A descriptive case series. Thirty-eight patients at three public hospitals, one tertiary and two secondary ophthalmic units in urban Australia. Forty eyes with dense mature cataracts with hand movement vision or worse underwent a planned manual small incision extracapsular cataract extraction instead of traditional phaco-emulsification. Postoperative visual aquity, surgically induced astigmatism and complications. Seventy-eight per cent of patients had an uncorrected visual acuity of 6/12 or better on the first postoperative day. Eighty-three per cent of patients had a distance corrected visual acuity of 6/9 or better 3 months postoperatively. One case was complicated by a posterior capsule rupture. No cases of endophthalmitis were reported. The summated vector mean of the surgically induced astigmatism was 0.089D at 93°. Manual small incision extracapsular cataract extraction is an efficacious cataract surgery technique with good visual outcome and is a safe alternative to phaco-emulsification in suitable cases in a first-world setting. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

[Increased occurrence of nuclear cataract in the calf after erection of a mobile phone base station].

PubMed

Hässig, M; Jud, F; Spiess, B

2012-02-01

We examined and monitored a dairy farm in which a large number of calves were born with nuclear cataracts after a mobile phone base station had been erected in the vicinity of the barn. Calves showed a 3.5 times higher risk for heavy cataract if born there compared to Swiss average. All usual causes such as infection or poisoning, common in Switzerland, could be excluded. The real cause of the increased incidence of cataracts remains unknown.

Cataract and keratoconus: minimizing complications in intraocular lens calculations.

PubMed

Bozorg, Sara; Pineda, Roberto

2014-01-01

Patients with both cataract and keratoconus present unique challenges for the surgeon. Accurate keratometry (K) and axial length (AL) readings may be impossible, and uncertainty is introduced when estimating the corneal power for intraocular lens (IOL) selection. Different options on how to choose an IOL and how to manage irregular astigmatism of a keratoconic patient with cataract have been proposed and are reviewed. The stage of keratoconus and the history of the patient are both critical in determining the strategy used in treatment of cataracts.

Outbreak of toxic anterior segment syndrome following cataract surgery associated with impurities in autoclave steam moisture.

PubMed

Hellinger, Walter C; Hasan, Saiyid A; Bacalis, Laura P; Thornblom, Deborah M; Beckmann, Susan C; Blackmore, Carina; Forster, Terri S; Tirey, Jason F; Ross, Mary J; Nilson, Christian D; Mamalis, Nick; Crook, Julia E; Bendel, Rick E; Shetty, Rajesh; Stewart, Michael W; Bolling, James P; Edelhauser, Henry F

2006-03-01

Toxic anterior segment syndrome (TASS), a complication of cataract surgery, is a sterile inflammation of the anterior chamber of the eye. An outbreak of TASS was recognized at an outpatient surgical center and its affiliated hospital in December 2002. Medical records of patients who underwent cataract surgery during the outbreak were reviewed, and surgical team members who participated in the operations were interviewed. Potential causes of TASS were identified and eliminated. Feedwater from autoclave steam generators and steam condensates were analyzed by use of spectroscopy and ion chromatography. During the outbreak, 8 (38%) of 21 cataract operations were complicated by TASS, compared with 2 (0.07%) of 2,713 operations performed from January 1996 through November 2002. Results of an initial investigation suggested that cataract surgical equipment may have been contaminated by suboptimal equipment reprocessing or as a result of personnel changes. The frequency of TASS decreased (1 of 44 cataract operations) after reassignment of personnel and revision of equipment reprocessing procedures. Further investigation identified the presence of impurities (eg, sulfates, copper, zinc, nickel, and silica) in autoclave steam moisture, which was attributed to improper maintenance of the autoclave steam generator in the outpatient surgical center. When impurities in autoclave steam moisture were eliminated, no cases of TASS were observed after more than 1,000 cataract operations. Suboptimal reprocessing of cataract surgical equipment may evolve over time in busy, multidisciplinary surgical centers. Clinically significant contamination of surgical equipment may result from inappropriate maintenance of steam sterilization systems. Standardization of protocols for reprocessing of cataract surgical equipment may prevent outbreaks of TASS and may be of assistance during outbreak investigations.

Evaluating the validity of clinical codes to identify cataract and glaucoma in the UK Clinical Practice Research Datalink.

PubMed

Kang, Elizabeth M; Pinheiro, Simone P; Hammad, Tarek A; Abou-Ali, Adel

2015-01-01

The aim of this study is to determine (i) the positive predictive value (PPV) of an algorithm using clinical codes to identify incident glaucoma and cataract events in the Clinical Practice Research Datalink (CPRD) and (ii) the ability to capture the correct timing of these clinical events. A total of 21,339 and 5349 potential cataract and glaucoma cases, respectively, were identified in CPRD between 1 January 1990 and 31 December 2010. Questionnaires were sent to the general practitioners (GP) of 1169 (5.5%) cataract and 1163 (21.7%) glaucoma cases for validation. GPs were asked to verify the diagnosis and the timing of the diagnosis and to provide other supporting information. A total of 986 (84.3%) valid cataract questionnaires and 863 (74.2%) glaucoma questionnaires were completed. 92.1% and 92.4% of these used information beyond EMR to verify the diagnosis. Cataract and glaucoma diagnoses were confirmed in the large majority of the cases. The PPV (95% CI) of the cataract and glaucoma Read code algorithm were 92.0% (90.3-93.7%) and 84.1% (81.7-86.6%), respectively. However, timing of diagnosis was incorrect for a substantial proportion of the cases (20.3% and 32.8% of the cataract and glaucoma cases, respectively) among whom 30.4% and 49.2% had discrepancies in diagnosis timing greater than 1 year. High PPV suggests that the algorithms based on the clinical Read codes are sufficient to identify the cataract and glaucoma cases in CPRD. However, these codes alone may not be able to accurately identify the timing of the diagnosis of these eye disorders. Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Rapid diagnosis of retina and optic nerve abnormalities in canine patients with and without cataracts using chromatic pupil light reflex testing.

PubMed

Grozdanic, Sinisa D; Kecova, Helga; Lazic, Tatjana

2013-09-01

To develop fast and reliable testing routines for diagnosing retina and optic nerve diseases in canine cataract patients based on chromatic properties of the pupillary light reflex response. Seventy-seven canine patients with a history of cataract and decreased vision (43 patients with cataracts and no evidence of retina or optic nerve disease, 21 patients with cataracts and retinal degeneration [RD], 13 patients with cataracts and retinal detachment [RDT]), 11 canine patients with optic neuritis (ON) and 23 healthy dogs were examined using chromatic pupillary light reflex (cPLR) analysis with red and blue light and electroretinography. Electroretinography analysis showed statistically significant deficits in a- and b-wave amplitudes in dogs with cataracts and RD, or cataracts and RDT, when compared to dogs with cataracts without evidence of retinal abnormalities. Evaluation of b-wave amplitudes showed that presence of 78.5-μV (or lower) amplitudes had high sensitivity of 100% (95% CI: 87.2-100%) and high specificity of 96.7% (95% CI: 88.4-100%) in RD and RDT. Evaluation of cPLR responses using red light showed that presence of the pupil end constriction diameter of 5.5 mm (or higher) had moderately high sensitivity of 76.5% (95% CI: 50.1-93.2%) and high specificity of 100% (95% CI: 91.2-100%) in detecting RD and RDT. Optic neuritis patients had absent cPLR responses, regardless of the visual status. Chromatic evaluation of the pupillary light reflex is a rapid and accurate test for diagnosing retina and optic nerve diseases in canine patients. © 2012 American College of Veterinary Ophthalmologists.

[Analysis of eye ultrasonography in patients with trinitrotoluene cataract].

PubMed

Huang, Dongmei; Zhu, Linping; Yang, Jinping; Wu, Donping

2015-04-01

To evaluate the diagnostic value of ultrasonography for trinitrotoluene (TNT) cataract. The morphology and internal echoes of 90 lenses of 45 TNT cataract patients and 120 lenses of 60 healthy adults were observed and compared using ultrasonography and slit lamp, and the hemodynamic parameters of the post-ophthalmic artery were also measured. The findings of the slit-lamp microscope were regarded as diagnostic criteria, and the sensitivity, specificity, and accordance rate of ultrasonography in the diagnosis of TNT cataract were calculated. The sensitivity, specificity, and accordance rate of ultrasonography in the diagnosis of TNT cataract were 93.33%, 100.00%, and 97.14%, respectively; the positive and negative predictive values were 100% and 95.23%, respectively; the positive and negative likelihood ratios were 93.33 and 0.67, especuvey. With the progression TNT cataract, utrasonography showed that the lenses demonstrated morphological changes (spindle-shaped, spherical, and discoid morphologies), and the arc echoes of the posterior capsule were thickened and enhanced. The TNT cataract patients showed significantly lower peak systolic velocity and end-diastolic velocity of the ophthalmic artery (OA) and central retinal artery (P<0.01) and a significantly higher resistance index (P<0.05) than the healthy adults. The sensitivity of ultrasonography in the diagnosis of TNT cataract is similar to that of slit lamp. Ultrasonography can demonstrate objectively the shape, range, and degree of lens opacity in an efficient manner, which is conducive to the diagnosis and staging of TNT cataract by slit lamp, and can also provide hemodynamic information of the OA, thus providing new ideas for clinical physicians in evaluating the disease and clinical efficacy as well as exploring therapies.

Catquest questionnaire for use in cataract surgery care: assessment of surgical outcomes.

PubMed

Lundström, M; Stenevi, U; Thorburn, W; Roos, P

1998-07-01

To demonstrate the outcome for patients after cataract extraction using the Catquest cataract questionnaire and discuss the models validity in assessing outcome. Thirty-five Swedish departments of ophthalmology. Patients having cataract extraction performed by surgeons from 35 Swedish departments of opthalmology participated in the study. The questionnaire was given to 2970 consecutive patients having surgery during March 1995 at the participating surgical units. The questionnaire was sent by mail to patients and completed on a voluntary basis. It focuses on visual disabilities in daily life, activity level, cataract symptoms, and degree of independence. The results form the questionnaire are interpreted using a benefit matrix that credits not only a decrease in visual disabilities and cataract symptoms but also an improvement in or maintenance of a preoperative activity level. Complete surgical outcome data and completed preoperative and postoperative questionnaires were available in 1933 cases (65.1%). Benefit from surgery according to the model was achieved by 90.9% of the patients. Patients having their second cataract extraction had the highest frequency of the greatest benefit form surgery. There was good agreement between the different levels of benefit from surgery according to the model and the patient's global rating of his or her vision or achieved visual acuity after surgery, respectively. Patients with missing data (did not return postoperative questionnaire or had missing surgical result variables) were older and had a higher frequency of other diseases and handicaps. The Catquest cataract questionnaire allowed the outcome of cataract surgery to be graded by different levels of benefit. There seemed to be good agreement between this model of assessment and the patient's global rating of his or her vision. Missing data may be a problem when a postal questionnaire is used.

Visual outcomes of bilateral congenital and developmental cataracts in young children in south India and causes of poor outcome.

PubMed

Khanna, Rohit C; Foster, Allen; Krishnaiah, Sannapaneni; Mehta, Manohar K; Gogate, Parikshit M

2013-02-01

Bilateral pediatric cataracts are important cause of visual impairment in children. To study the outcome of bilateral pediatric cataract surgery in young children. Retrospective case series in a tertiary center. Records of pediatric cataracts operated between January 2001 and December 2003, with a minimum follow-up of 3 months, were reviewed retrospectively. Independent sample t-test, Fisher's exact test, and logistic regression using SPSS (Statistical Package for Social Science, Chicago, USA) version 12. 215/257 (83.7%) patients had a minimum follow-up of 3 months. The mean age of presentation to the hospital was 53 months (range: 0-168 months). Congenital cataract was present in 107 patients (58.2%) and developmental cataract in 77 patients (41.8%). The mean age at surgery was 55.2 months (range: 1-168 months). Out of 430 eyes, 269 (62.6%) had an intraocular lens implanted. The mean duration of follow-up was 13.1 months (range: 3-38 months). Pre-operatively, 102 patients (47.3%) had visual acuity <6/60, in the better eye, compared to 37 patients (17.2%) post-operatively ( P < 0.001). Eighty-five patients (39.5%) had visual acuity >6/18. The most common early post-operative complication was fibrinous uveitis in 57 eyes (13.3%) and the most common delayed post-operative complication was posterior capsular opacification in 118 eyes (27.4%). The most important prognostic factor for poor outcome was congenital cataract (odds ratio [OR]: 26.3; 95% confidence interval [CI], 4.4-158.5) and total cataract (OR: 4.8; 95% CI, 1.3-17). Nearly half of the eyes had visual acuity >6/18. The outcome was poorer in congenital cataracts, especially those operated after >1 year of age.

Phenotypes of Recessive Pediatric Cataract in a Cohort of Children with Identified Homozygous Gene Mutations (An American Ophthalmological Society Thesis)

PubMed Central

Khan, Arif O.; Aldahmesh, Mohammed A.; Alkuraya, Fowzan S.

2015-01-01

Purpose: To assess for phenotype-genotype correlations in families with recessive pediatric cataract and identified gene mutations. Methods: Retrospective review (2004 through 2013) of 26 Saudi Arabian apparently nonsyndromic pediatric cataract families referred to one of the authors (A.O.K.) and for which recessive gene mutations were identified. Results: Fifteen different homozygous recessive gene mutations were identified in the 26 consanguineous families; two genes and five families are novel to this study. Ten families had a founder CRYBB1 deletion (all with bilateral central pulverulent cataract), two had the same missense mutation in CRYAB (both with bilateral juvenile cataract with marked variable expressivity), and two had different mutations in FYCO1 (both with bilateral posterior capsular abnormality). The remaining 12 families each had mutations in 12 different genes (CRYAA, CRYBA1, AKR1E2, AGK, BFSP2, CYP27A1, CYP51A1, EPHA2, GCNT2, LONP1, RNLS, WDR87) with unique phenotypes noted for CYP27A1 (bilateral juvenile fleck with anterior and/or posterior capsular cataract and later cerebrotendinous xanthomatosis), EPHA2 (bilateral anterior persistent fetal vasculature), and BFSP2 (bilateral flecklike with cloudy cortex). Potential carrier signs were documented for several families. Conclusions: In this recessive pediatric cataract case series most identified genes are noncrystallin. Recessive pediatric cataract phenotypes are generally nonspecific, but some notable phenotypes are distinct and associated with specific gene mutations. Marked variable expressivity can occur from a recessive missense CRYAB mutation. Genetic analysis of apparently isolated pediatric cataract can sometimes uncover mutations in a syndromic gene. Some gene mutations seem to be associated with apparent heterozygous carrier signs. PMID:26622071

Cortical, but Not Posterior Subcapsular, Cataract Shows Significant Familial Aggregation in an Older Population after Adjustment for Possible Shared Environmental Factors

PubMed Central

Congdon, Nathan; Broman, Karl W.; Lai, Hong; Munoz, Beatriz; Bowie, Heidi; Gilbert, Donna; Wojciechowski, Robert; West, Sheila K.

2011-01-01

Purpose To quantify the risk for age-related cortical cataract and posterior subcapsular cataract (PSC) associated with having an affected sibling after adjusting for known environmental and personal risk factors. Design Sibling cohort study. Participants Participants in the ongoing Salisbury Eye Evaluation (SEE) study (n = 321; mean age, 78.1±4.2 years) and their locally resident siblings (n = 453; mean age, 72.6±7.4 years) were recruited at the time of Rounds 3 and 4 of the SEE study. Intervention/Testing Methods Retroillumination photographs of the lens were graded for the presence of cortical cataract and PSC with the Wilmer grading system. The residual correlation between siblings' cataract grades was estimated after adjustment for a number of factors (age; gender; race; lifetime exposure to ultraviolet-B light; cigarette, alcohol, estrogen, and steroid use; serum antioxidants; history of diabetes; blood pressure; and body mass index) suspected to be associated with the presence of cataract. Results The average sibship size was 2.7 per family. Multivariate analysis revealed the magnitude of heritability (h2) for cortical cataract to be 24% (95% CI, 6%–42%), whereas that for PSC was not statistically significant (h2 4%; 95% CI, 0%–11%) after adjustment for the covariates. The model revealed that increasing age, female gender, a history of diabetes, and black race increased the odds of cortical cataract, whereas higher levels of provitamin A were protective. A history of diabetes and steroid use increased the odds for PSC. Conclusions This study is consistent with a significant genetic effect for age-related cortical cataract but not PSC. PMID:15629823

Cataract Surgery Outcomes in Glaucomatous Eyes: Results From the Veterans Affairs Ophthalmic Surgery Outcomes Data Project.

PubMed

Turalba, Angela; Payal, Abhishek R; Gonzalez-Gonzalez, Luis A; Cakiner-Egilmez, Tulay; Chomsky, Amy S; Vollman, David E; Baze, Elizabeth F; Lawrence, Mary; Daly, Mary K

2015-10-01

To compare visual acuity outcomes, vision-related quality of life, and complications related to cataract surgery in eyes with and without glaucoma. Retrospective cohort study. Cataract surgery outcomes in cases with and without glaucoma from the Veterans Affairs Ophthalmic Surgical Outcomes Data Project were compared. We identified 608 glaucoma cases and 4306 controls undergoing planned cataract surgery alone. After adjusting for age, pseudoexfoliation, small pupil, prior ocular surgery, and anterior chamber depth, we found that glaucoma cases were more likely to have posterior capsular tear with vitrectomy (odds ratio [OR] 1.8, P = .03) and sulcus intraocular lens placement (OR 1.65, P = .03) during cataract surgery. Glaucoma cases were more likely to have postoperative inflammation (OR 1.73, P < .0001), prolonged elevated intraocular pressure (OR 2.96, P = .0003), and additional surgery within 30 days (OR 1.92, P = .03). Mean best-corrected visual acuity (BCVA) and Visual Function Questionnaire (VFQ) scores significantly improved after cataract surgery in both groups (P < .0001), but there were larger improvements in BCVA (P = .01) and VFQ composite scores (P < .0001) in the nonglaucoma vs the glaucoma group. A total of 3621 nonglaucoma cases (94.1%) had postoperative BCVA 20/40 or better, compared to 466 glaucoma cases (89.6%) (P = .0003). Eyes with glaucoma are at increased risk for complications and have more modest visual outcomes after cataract surgery compared to eyes without glaucoma. Despite this, glaucoma patients still experience significant improvement in vision-related outcomes after cataract extraction. Further study is needed to explore potential factors that influence cataract surgery outcomes in glaucomatous eyes. Published by Elsevier Inc.

Prevalence and causes of visual impairment and blindness, cataract surgical coverage and outcomes of cataract surgery in Libya.

PubMed

Rabiu, Muhammad Mansur; Jenf, Mansour; Fituri, Suad; Choudhury, Abdulhanan; Agbabiaka, Idris; Mousa, Ahmed

2013-01-01

To assess the major causes of avoidable blindness, and outcomes and barriers to cataract services in Libya. A stratified multistage cluster random sample study was conducted in the four regions of Libya. Visual acuity and lens assessment were performed on all subjects. Those with presenting visual acuity <6/18 in either or both eyes were further investigated to determine cause(s) of impairment. Barriers to cataract surgery were investigated. Visual outcomes of subjects with surgery performed were assessed. A total of 8538 persons aged ≥50 years were examined across the four regions. The prevalence of blindness was 3.25% (3.15% with best correction), which varied across the regions (2.94-3.80%); after adjustment for age and sex, the prevalence was 2.66%. Major causes of blindness were cataract (29%), glaucoma (24%) and other corneal scars (14%). Causes were similar across all regions except in the south. Avoidable causes were responsible for 60.6% of blindness. Major causes of visual impairment were cataract (31.2%), diabetic retinopathy (16.6%) and posterior segment diseases (15.1%). Cataract surgical coverage among those with visual acuity <3/60 was 95.4%, with no sex differences. About 38% of cataract-operated eyes had poor outcome even after best correction (35%). There was poor outcome in 33% of pseudophakic eyes with best correction. The major barriers to service uptake were "waiting for maturity" (26%), "unaware of treatment" (24%) and "God's will/destiny" (17%). Libya needs to improve the quality of cataract surgery across all the regions. The southern region needs improvement in both quality and coverage of services.

Long term outcomes of bilateral congenital and developmental cataracts operated in Maharashtra, India. Miraj pediatric cataract study III.

PubMed

Gogate, Parikshit M; Sahasrabudhe, Mohini; Shah, Mitali; Patil, Shailbala; Kulkarni, Anil N; Trivedi, Rupal; Bhasa, Divya; Tamboli, Rahin; Mane, Rekha

2014-02-01

To study long term outcome of bilateral congenital and developmental cataract surgery. 258 pediatric cataract operated eyes of 129 children. Children who underwent pediatric cataract surgery in 2004-8 were traced and examined prospectively in 2010-11. Demographic and clinical factors were noted from retrospective chart readings. All children underwent visual acuity estimation and comprehensive ocular examination in a standardized manner. L. V. Prasad Child Vision Function scores (LVP-CVF) were noted for before and after surgery. Statistical analysis was done with SPSS version 16 including multi-variate analysis. Children aged 9.1 years (std dev 4.6, range 7 weeks-15 years) at the time of surgery. 74/129 (57.4%) were boys. The average duration of follow-up was 4.4 years (stddev 1.6, range 3-8 years). 177 (68.6%) eyes had vision <3/60 before surgery, while 109 (42.2%) had best corrected visual acuity (BCVA) >6/18 and 157 (60.9%) had BCVA >6/60 3-8 years after surgery. 48 (37.2%) had binocular stereoacuity <480 sec of arc by TNO test. Visual outcome depended on type of cataract (P = 0.004), type of cataract surgery (P < 0.001), type of intra-ocular lens (P = 0.05), age at surgery (P = 0.004), absence of post-operative uveitis (P = 0.01) and pre-operative vision (P < 0.001), but did not depend on delay (0.612) between diagnosis and surgery. There was a statistically significant improvement for all the 20 questions of the LVP-CVF scale (P < 0.001). Pediatric cataract surgery improved the children's visual acuity, stereo acuity and vision function. Developmental cataract, use of phacoemulsification, older children and those with better pre-operative vision had betterlong-termoutcomes.

How the venetian blind percept emerges from the laminar cortical dynamics of 3D vision

PubMed Central

Cao, Yongqiang; Grossberg, Stephen

2014-01-01

The 3D LAMINART model of 3D vision and figure-ground perception is used to explain and simulate a key example of the Venetian blind effect and to show how it is related to other well-known perceptual phenomena such as Panum's limiting case. The model proposes how lateral geniculate nucleus (LGN) and hierarchically organized laminar circuits in cortical areas V1, V2, and V4 interact to control processes of 3D boundary formation and surface filling-in that simulate many properties of 3D vision percepts, notably consciously seen surface percepts, which are predicted to arise when filled-in surface representations are integrated into surface-shroud resonances between visual and parietal cortex. Interactions between layers 4, 3B, and 2/3 in V1 and V2 carry out stereopsis and 3D boundary formation. Both binocular and monocular information combine to form 3D boundary and surface representations. Surface contour surface-to-boundary feedback from V2 thin stripes to V2 pale stripes combines computationally complementary boundary and surface formation properties, leading to a single consistent percept, while also eliminating redundant 3D boundaries, and triggering figure-ground perception. False binocular boundary matches are eliminated by Gestalt grouping properties during boundary formation. In particular, a disparity filter, which helps to solve the Correspondence Problem by eliminating false matches, is predicted to be realized as part of the boundary grouping process in layer 2/3 of cortical area V2. The model has been used to simulate the consciously seen 3D surface percepts in 18 psychophysical experiments. These percepts include the Venetian blind effect, Panum's limiting case, contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and perceptual closure. These model mechanisms have also simulated properties of 3D neon color spreading, binocular rivalry, 3D Necker cube, and many examples of 3D figure-ground separation. PMID:25309467

How the venetian blind percept emerges from the laminar cortical dynamics of 3D vision.

PubMed

Cao, Yongqiang; Grossberg, Stephen

2014-01-01

The 3D LAMINART model of 3D vision and figure-ground perception is used to explain and simulate a key example of the Venetian blind effect and to show how it is related to other well-known perceptual phenomena such as Panum's limiting case. The model proposes how lateral geniculate nucleus (LGN) and hierarchically organized laminar circuits in cortical areas V1, V2, and V4 interact to control processes of 3D boundary formation and surface filling-in that simulate many properties of 3D vision percepts, notably consciously seen surface percepts, which are predicted to arise when filled-in surface representations are integrated into surface-shroud resonances between visual and parietal cortex. Interactions between layers 4, 3B, and 2/3 in V1 and V2 carry out stereopsis and 3D boundary formation. Both binocular and monocular information combine to form 3D boundary and surface representations. Surface contour surface-to-boundary feedback from V2 thin stripes to V2 pale stripes combines computationally complementary boundary and surface formation properties, leading to a single consistent percept, while also eliminating redundant 3D boundaries, and triggering figure-ground perception. False binocular boundary matches are eliminated by Gestalt grouping properties during boundary formation. In particular, a disparity filter, which helps to solve the Correspondence Problem by eliminating false matches, is predicted to be realized as part of the boundary grouping process in layer 2/3 of cortical area V2. The model has been used to simulate the consciously seen 3D surface percepts in 18 psychophysical experiments. These percepts include the Venetian blind effect, Panum's limiting case, contrast variations of dichoptic masking and the correspondence problem, the effect of interocular contrast differences on stereoacuity, stereopsis with polarity-reversed stereograms, da Vinci stereopsis, and perceptual closure. These model mechanisms have also simulated properties of 3D neon color spreading, binocular rivalry, 3D Necker cube, and many examples of 3D figure-ground separation.

Intraocular lens employed for cataract surgery

NASA Astrophysics Data System (ADS)

Roszkowska, A. M.; Torrisi, L.

2014-04-01

The aim of this paper is to illustrate the techniques of cataract surgery with implantation of intraocular lenses and some physical properties of the used materials. The new technology, coupled with extensive experience and the studied cases, permits to increase the standardization and accuracy of the engravings, by reducing the use and handling of surgical instruments inside the eye. At present it is possible to replace the cataract with crystalline lenses based on biopolymers such as PMMA, silicone, acrylic hydrophilic and hydrophobic acrylic. These materials are increasingly able to replace the natural lens and to ensure the fully functional of the eye. The role of femtosecond lasers in cataract surgery, to assist or replace several aspects of the manual cataract surgery, are discussed.

Cataract surgery audit at an Australian urban teaching hospital.

PubMed

Kahawita, Shyalle K; Goggin, Michael

2015-08-01

To provide local data on visual acuity and surgical outcomes for cataract surgery performed in an Australian teaching hospital. Continuous audit over 7 years in a public teaching hospital. A total of 3740 eyes had cataract surgery performed at The Queen Elizabeth Hospital, South Australia, from May 2006 to September 2013. Visual acuity and complication rates were recorded for cataract surgery cases operated on between May 2006 and September 2013 on a digital database with data entry contemporaneous with final follow-up. Visual acuity and surgical complications. Of the patients, 91.4% achieved postoperative best-measured vision better than preoperative best-measured vision. The rate of posterior capsular tear was 2.59%, endophthalmitis was 0.11% and the overall complication rate was 11.7%. This audit is the first to document modern cataract surgery, overwhelmingly dominated by phacoemulsification in an Australian population and can be used to benchmark cataract surgery outcome in an urban Australian population. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

Impact of nuclear cataract density on postoperative refractive outcome: IOL Master versus ultrasound.

PubMed

Ueda, Tetsuo; Taketani, Futoshi; Ota, Takeo; Hara, Yoshiaki

2007-01-01

To evaluate the effect of cataract density on the postoperative refractive outcome. For 59 nuclear cataract eyes, the axial length was preoperatively measured by the IOL Master (Zeiss, Germany) and ultrasound (US; UD-6000, Tomey, Japan) and the cataract density by EAS-1000 (Nidek, Japan). The prediction error was used as evaluation of the accuracy of ocular biometry. There were significant differences between IOL Master and US in the mean error (0.24 +/- 0.63 vs. 0.69 +/- 0.64 dpt, p < 0.001) and the mean absolute error (0.57 +/- 0.36 vs. 0.79 +/- 0.53 dpt, p < 0.001). The cataract density was significantly correlated with the prediction error with IOL Master (r = 0.24, p = 0.03) and US (r = 0.29, p = 0.01). Measurements with the IOL Master are slightly affected by the cataract density due to the refractive index change, but its accuracy is less affected than US. (c) 2007 S. Karger AG, Basel.

Laser-assisted cataract surgery: benefits and barriers.

PubMed

Hatch, Kathryn M; Talamo, Jonathan H

2014-01-01

The use of the femtosecond laser (FSL) in cataract surgery may represent the largest advancement in the field since the inception of phacoemulsification. The goal of this review is to outline the benefits of and barriers to this technology. There are several significant potential benefits of the FSL in cataract surgery over conventional manual cataract surgery: precise capsulotomy formation, clear corneal and limbal relaxing incision construction, lens fragmentation, and lens softening. Evidence suggests that refractive benefits include more precise effective lens position as well as reduced effective phacoemulsification time with the use of FSL compared with manual surgery. Patients with conditions such as Fuchs' endothelial dystrophy, pseudoexfoliation, history of trauma, or brunescent cataracts may particularly benefit from this technology. There are significant financial and logistical issues to consider prior to the purchase of a FSL, including the cost of the laser, and charges to patients, and how the laser affects the patient flow in the operating room. The FSL may significantly change the current approach to cataract surgery.

A computer-aided diagnosis system of nuclear cataract.

PubMed

Li, Huiqi; Lim, Joo Hwee; Liu, Jiang; Mitchell, Paul; Tan, Ava Grace; Wang, Jie Jin; Wong, Tien Yin

2010-07-01

Cataracts are the leading cause of blindness worldwide, and nuclear cataract is the most common form of cataract. An algorithm for automatic diagnosis of nuclear cataract is investigated in this paper. Nuclear cataract is graded according to the severity of opacity using slit lamp lens images. Anatomical structure in the lens image is detected using a modified active shape model. On the basis of the anatomical landmark, local features are extracted according to clinical grading protocol. Support vector machine regression is employed for grade prediction. This is the first time that the nucleus region can be detected automatically in slit lamp images. The system is validated using clinical images and clinical ground truth on >5000 images. The success rate of structure detection is 95% and the average grading difference is 0.36 on a 5.0 scale. The automatic diagnosis system can improve the grading objectivity and potentially be used in clinics and population studies to save the workload of ophthalmologists.

The First Cataract Surgeons in Anglo-America

PubMed Central

Leffler, Christopher T.; Schwartz, Stephen G.; Grzybowski, Andrzej; Braich, Puneet S.

2014-01-01

We tried to identify the earliest cataract surgeons in the English-speaking areas of America. In 1751, couching was performed on the Caribbean island of Montserrat by John Morphy. William Stork of England, who couched cataracts, practiced in Jamaica in 1760 and then in cities from Annapolis to Boston between 1761 and 1764. Frederick William Jericho of Germany, upon completion of his training at Utrecht, published his 1767 treatise on his preferred surgical technique of extracapsular cataract extraction. Jericho had practiced in the Leeward Islands by 1776 and then in cities from Charleston to Boston between 1783 and 1785. The French surgeon Lewis Leprilete was the first to advertise cataract extraction in the United States in 1782 and probably passed on the skill to his protégé, Nathaniel Miller of Massachusetts. Leprilete was also the first to publicize Benjamin Franklin's invention of bifocals.. These pioneers exposed American doctors and the public to cataract surgery. Shortly after their arrival, evidence emerges of other surgeons performing these procedures in America. PMID:25444521

[Cataract surgery under topical anesthesia with oral anticoagulants].

PubMed

Wirbelauer, C; Weller, A; Häberle, H; Pham, D T

2004-09-01

Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective study, the influence of oral anticoagulants on intraoperative and postoperative hemorrhages in patients undergoing cataract surgery in topical anesthesia was investigated. 128 patients presenting for cataract surgery under oral anticoagulation were included. The mean preoperative prothrombin time was 39 +/- 18 %. Most patients (81 %) continued their oral anticoagulation (prothrombin time 34 +/- 13 %). All surgeries were performed in topical anesthesia. In 9 patients (7 %) an ocular hemorrhagic event was observed. These were not sight-threatening and resorbed spontaneously within a few days. Only one patient (0.8 %) had a slight hemorrhage in the anterior chamber. There were no differences (P > 0.05) between patients with or without hemorrhagic complications in the postoperative visual acuity, the intraocular pressure, the prothrombin time or the discontinuation of oral anticoagulants. Cataract surgery in topical anesthesia under oral anticoagulation did not increase the risk of sight-threatening hemorrhages. The continuation of oral anticoagulation seems particularly indicated for ambulatory cataract surgery.

Cataract frequency and subtypes involved in workers assessed for their solar radiation exposure: a systematic review.

PubMed

Modenese, Alberto; Gobba, Fabriziomaria

2018-04-16

Cataract is currently the primary cause of blindness worldwide, and one of its main risk factors is solar ultraviolet radiation exposure. According to the localization of lens opacities, three main subtypes of cataract are recognized: nuclear, cortical and posterior subcapsular cataract. One of the main determinants of individual long-term solar radiation exposure is outdoor work. We systematically reviewed scientific literature from the last 20 years to update the recent development of research on the risk of cataract in outdoor workers and on the specific subtypes involved, also investigating the methods applied to evaluate the occupational risk. A total of 15 studies were included in the review, of which 12 showed a positive association. The studies confirm the relationship of long-term occupational solar radiation exposure with cortical cataract and give new support for nuclear cataract, although no substantial new data were available to support a relation with the posterior subcapsular subtype. In most of the studies, the exposure assessment was not adequate to support a representative evaluation of the ocular risk; however, outdoor work is clearly a relevant risk factor for cataract. Further research providing a better evaluation of the relation between solar radiation exposure levels and lens damage in workers is needed and aimed to establish adequate occupational exposure limits and better preventive measures, studying also their effectiveness. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Importance of multi-modal approaches to effectively identify cataract cases from electronic health records.

PubMed

Peissig, Peggy L; Rasmussen, Luke V; Berg, Richard L; Linneman, James G; McCarty, Catherine A; Waudby, Carol; Chen, Lin; Denny, Joshua C; Wilke, Russell A; Pathak, Jyotishman; Carrell, David; Kho, Abel N; Starren, Justin B

2012-01-01

There is increasing interest in using electronic health records (EHRs) to identify subjects for genomic association studies, due in part to the availability of large amounts of clinical data and the expected cost efficiencies of subject identification. We describe the construction and validation of an EHR-based algorithm to identify subjects with age-related cataracts. We used a multi-modal strategy consisting of structured database querying, natural language processing on free-text documents, and optical character recognition on scanned clinical images to identify cataract subjects and related cataract attributes. Extensive validation on 3657 subjects compared the multi-modal results to manual chart review. The algorithm was also implemented at participating electronic MEdical Records and GEnomics (eMERGE) institutions. An EHR-based cataract phenotyping algorithm was successfully developed and validated, resulting in positive predictive values (PPVs) >95%. The multi-modal approach increased the identification of cataract subject attributes by a factor of three compared to single-mode approaches while maintaining high PPV. Components of the cataract algorithm were successfully deployed at three other institutions with similar accuracy. A multi-modal strategy incorporating optical character recognition and natural language processing may increase the number of cases identified while maintaining similar PPVs. Such algorithms, however, require that the needed information be embedded within clinical documents. We have demonstrated that algorithms to identify and characterize cataracts can be developed utilizing data collected via the EHR. These algorithms provide a high level of accuracy even when implemented across multiple EHRs and institutional boundaries.

Electronic medical records and genomics (eMERGE) network exploration in cataract: Several new potential susceptibility loci

PubMed Central

Verma, Shefali S.; Hall, Molly A.; Goodloe, Robert J.; Berg, Richard L.; Carrell, Dave S.; Carlson, Christopher S.; Chen, Lin; Crosslin, David R.; Denny, Joshua C.; Jarvik, Gail; Li, Rongling; Linneman, James G.; Pathak, Jyoti; Peissig, Peggy; Rasmussen, Luke V.; Ramirez, Andrea H.; Wang, Xiaoming; Wilke, Russell A.; Wolf, Wendy A.; Torstenson, Eric S.; Turner, Stephen D.; McCarty, Catherine A.

2014-01-01

Purpose Cataract is the leading cause of blindness in the world, and in the United States accounts for approximately 60% of Medicare costs related to vision. The purpose of this study was to identify genetic markers for age-related cataract through a genome-wide association study (GWAS). Methods In the electronic medical records and genomics (eMERGE) network, we ran an electronic phenotyping algorithm on individuals in each of five sites with electronic medical records linked to DNA biobanks. We performed a GWAS using 530,101 SNPs from the Illumina 660W-Quad in a total of 7,397 individuals (5,503 cases and 1,894 controls). We also performed an age-at-diagnosis case-only analysis. Results We identified several statistically significant associations with age-related cataract (45 SNPs) as well as age at diagnosis (44 SNPs). The 45 SNPs associated with cataract at p<1×10−5 are in several interesting genes, including ALDOB, MAP3K1, and MEF2C. All have potential biologic relationships with cataracts. Conclusions This is the first genome-wide association study of age-related cataract, and several regions of interest have been identified. The eMERGE network has pioneered the exploration of genomic associations in biobanks linked to electronic health records, and this study is another example of the utility of such resources. Explorations of age-related cataract including validation and replication of the association results identified herein are needed in future studies. PMID:25352737

Cataract blindness in Turkmenistan: results of a national survey

PubMed Central

Amansakhatov, S; Volokhovskaya, Z P; Afanasyeva, A N; Limburg, H

2002-01-01

Aim: To present results of a rapid assessment of cataract in Turkmenistan. Methods: 6120 eligible people of 50 years and older were selected by systematic random sampling from the whole of Turkmenistan. A total of 6011 people were examined (coverage 98.2%). Results: Cataract is the major cause of bilateral blindness (54%), followed by glaucoma (25%). The age and sex adjusted prevalence of bilateral cataract blindness (VA <3/60) in people of 50 years and older was 0.6% (95% CI: 0.4 to 0.9), with a cataract surgical coverage of 75% (people). For VA <6/60 the prevalence was 2.6% (95% CI: 2.1 to 3.2) in people aged 50 and above, approximately 0.26% of the total population. In this last group the surgical coverage was 44% (people) and 32% (eyes). Of the patients operated with IOL implantation 8.2% could not see 6/60, 44.8% of those operated without IOL could not see 6/60. The main barrier to cataract surgery was indifference (“old age, no need for surgery”), followed by “waiting for maturity.” Conclusion: To increase the cataract surgical coverage in Turkmenistan the intake criteria should be lowered to VA <6/60 or less. At the same time the visual outcome of surgery can be improved by expanding the number of IOL surgeries and routine monitoring of cataract outcome. Additional investments will be required to provide all eye surgeons with appropriate equipment and skills for IOL surgery. PMID:12386068

Healthy Diets and the Subsequent Prevalence of Nuclear Cataract in Women

PubMed Central

Mares, Julie A.; Voland, Rick; Adler, Rachel; Tinker, Lesley; Millen, AE; Moeller, Suzen M.; Blodi, Barbara; Gehrs, Karen M.; Wallace, Robert B.; Chappell, Richard J.; Neuhouser, Marian L.; Sarto, G

2009-01-01

Objective and Design The association between healthy diet scores which reflect adherence to the US Dietary Guidelines and prevalence of nuclear cataract, assessed four to seven years later, was assessed in a sample of Women's Health Initiative (WHI) Observational Study participants (50–79 years of age) who were residing in Iowa, Wisconsin and Oregon. Scores on the 1995 Healthy Eating Index (HEI-95), which reflect adherence to 1990 guidelines, were assigned from responses to food frequency questionnaires at WHI-baseline (1994–1998). Presence of nuclear cataract was determined from slit-lamp photographs and self-report of cataract extractions were assessed from 2001–04 in the Carotenoids in Age-Related Eye Disease Study (N=1,808). Results Having a high HEI-95 score was the strongest modifiable predictor of low prevalence of nuclear cataract among numerous risk factors investigated in this sample. The multivariable-adjusted OR and 95% confidence interval for high vs. low quintile for diet score were 0.6 (0.4–0.9). Higher prevalence of nuclear cataract was also associated with other modifiable factors (smoking and marked obesity) and non-modifiable factors (having brown eyes, myopia and high pulse pressure). Vitamin supplement use was not related to cataract. Conclusion These data add to the body of evidence suggesting that eating foods that are rich in a variety of vitamins and minerals, may contribute to postponing the occurrence of the most common type of cataract in the US. PMID:20547952

Cerebrotendinous xanthomatosis (CTX): an association of pulverulent cataracts and pseudo-dominant developmental delay in a family with a splice site mutation in CYP27A1--a case report.

PubMed

Bourkiza, Rabia; Joyce, Sarah; Patel, Himanshu; Chan, Michelle; Meyer, Esther; Maher, Eamonn R; Reddy, M Ashwin

2010-06-01

A 15-year-old boy with developmental delay presented to the pediatric ophthalmology clinic with bilateral pulverulent cataracts. The family was examined for developmental delay, cataracts and systemic problems. The parents were consanguineous and originally from Bangladesh. All the children were born in the UK. The mother and 5 children had developmental delay. Three children had global developmental delay, diarrhea and pulverulent cataracts. Two children had microcephaly, developmental delay, constipation and no cataracts. The mother did not have microcephaly, cataracts or gastrointestinal problems. Linkage analysis via autozygosity testing was performed for detection of loci and candidate genes. The patients with cataracts were segregated with homozygous mutations in the CYP27A1 (G to A substitution at position +1 of intron 6). The complex nature of this family's findings suggested that it had an unusual autosomal dominant condition with variable expression. Autozygosity testing demonstrated that three members had Cerebrotendinous xanthomatosis (CTX), which is inherited in an autosomal recessive manner. The aetiology of the developmental delay in other family members remains unknown. Cerebrotendinous xanthomatosis is a rare autosomal recessive condition that can result in neurological deficits and early death if left untreated. In view of the reversible nature of the condition with appropriate treatment, there needs to be a high level of suspicion of CTX for any child with cataracts and developmental delay even if the pattern of inheritance is not straightforward at initial assessment.

Visual field changes after cataract extraction: the AGIS experience.

PubMed

Koucheki, Behrooz; Nouri-Mahdavi, Kouros; Patel, Gitane; Gaasterland, Douglas; Caprioli, Joseph

2004-12-01

To test the hypothesis that cataract extraction in glaucomatous eyes improves overall sensitivity of visual function without affecting the size or depth of glaucomatous scotomas. Experimental study with no control group. One hundred fifty-eight eyes (of 140 patients) from the Advanced Glaucoma Intervention Study with at least two reliable visual fields within a year both before and after cataract surgery were included. Average mean deviation (MD), pattern standard deviation (PSD), and corrected pattern standard deviation (CPSD) were compared before and after cataract extraction. To evaluate changes in scotoma size, the number of abnormal points (P < .05) on the pattern deviation plot was compared before and after surgery. We described an index ("scotoma depth index") to investigate changes of scotoma depth after surgery. Mean values for MD, PSD, and CPSD were -13.2, 6.4, and 5.9 dB before and -11.9, 6.8, and 6.2 dB after cataract surgery (P < or = .001 for all comparisons). Mean (+/- SD) number of abnormal points on pattern deviation plot was 26.7 +/- 9.4 and 27.5 +/- 9.0 before and after cataract surgery, respectively (P = .02). Scotoma depth index did not change after cataract extraction (-19.3 vs -19.2 dB, P = .90). Cataract extraction caused generalized improvement of the visual field, which was most marked in eyes with less advanced glaucomatous damage. Although the enlargement of scotomas was statistically significant, it was not clinically meaningful. No improvement of sensitivity was observed in the deepest part of the scotomas.

Measurements of attenuation coefficient for evaluating the hardness of a cataract lens by a high-frequency ultrasonic needle transducer.

PubMed

Huang, Chih-Chung; Chen, Ruimin; Tsui, Po-Hsiang; Zhou, Qifa; Humayun, Mark S; Shung, K Kirk

2009-10-07

A cataract is a clouding of the lens in the eye that affects vision. Phacoemulsification is the mostly common surgical method for treating cataracts, and determining that the optimal phacoemulsification energy is dependent on measuring the hardness of the lens. This study explored the use of an ultrasound needle transducer for invasive measurements of ultrasound attenuation coefficient to evaluate the hardness of the cataract lens. A 47 MHz high-frequency needle transducer with a diameter of 0.9 mm was fabricated by a polarized PMN-33%PT single crystal in the present study. The attenuation coefficients at different stages of an artificial porcine cataract lens were measured using the spectral shift approach. The hardness of the cataract lens was also evaluated by mechanical measurement of its elastic properties. The results demonstrated that the ultrasonic attenuation coefficient was increased from 0.048 +/- 0.02 to 0.520 +/- 0.06 dB mm(-1) MHz(-1) corresponding to an increase in Young's modulus from 6 +/- 0.4 to 96 +/- 6.2 kPa as the cataract further developed. In order to evaluate the feasibility of combining needle transducer and phacoemulsification probe for real-time measurement during cataract surgery, the needle transducer was mounted on the phacoemulsification probe for a vibration test. The results indicated that there was no apparent damage to the tip of the needle transducer and the pulse-echo test showed that a good performance in sensitivity was maintained after the vibration test.

Waiting time for cataract surgery and its influence on patient attitudes.

PubMed

Chan, Frank Wan-kin; Fan, Alex Hoi; Wong, Fiona Yan-yan; Lam, Philip Tsze-ho; Yeoh, Eng-kiong; Yam, Carrie Ho-kwan; Griffiths, Sian; Lam, Dennis Shun-chiu; Congdon, Nathan

2009-08-01

To characterize willingness to pay for private operations and preferred waiting time among patients awaiting cataract surgery in Hong Kong. This was a cross-sectional survey. Subjects randomly selected from cataract surgical waiting lists in Hong Kong (n = 467) underwent a telephone interview based on a structured, validated questionnaire. Data were collected on private insurance coverage, preferred waiting time, amount willing to pay for surgery, and self-reported visual function and health status. Among 300 subjects completing the interview, 144 (48.2%) were 76 years of age or older, 177 (59%) were women, and mean time waiting for surgery was 17 +/- 15 months. Among 220 subjects (73.3%) willing to pay anything for surgery, the mean amount was US$552 +/- 443. With adjustment for age, education, and monthly household income, subjects willing to pay anything were less willing to wait 12 months for surgery (OR = 4.34; P = 0.002), more likely to know someone having had cataract surgery (OR = 2.20; P = 0.03), and more likely to use their own savings to pay for the surgery (OR = 2.21; P = 0.04). Subjects considering private cataract surgery, knowing people who have had cataract surgery, using nongovernment sources to pay for surgery, and having lower visual function were willing to pay more. Many patients wait significant periods for cataract surgery in Hong Kong, and are willing to pay substantial amounts for private operations. These results may have implications for other countries with cataract waiting lists.

Managing the posterior polar cataract: An update

PubMed Central

Vasavada, Abhay R; Vasavada, Vaishali A

2017-01-01

Posterior polar cataracts (PPC) have always been a challenge for cataract surgeons due to their inherently higher propensity for posterior capsule rupture. Over the years, several technical modifications have been suggested to enhance safety and reduce posterior capsule rupture rates in these polar cataracts. This review article tries to present the various techniques and strategies to published in literature to manage PPCs. It also discusses pearls for making surgery more reproducible and consistent, as well as the role of newer diagnostic and surgical technology based on the published literature on the subject. PMID:29208815

Femtosecond laser-assisted cataract surgery in pediatric patients.

PubMed

Corredor-Ortega, Claudia; Gonzalez-Salinas, Roberto; Montero, María José; González-Flores, Rocío; Collura-Merlier, Allan; Cervantes-Coste, Guadalupe; Mendoza-Schuster, Erick; Velasco-Barona, Cecilio

2018-04-01

Pediatric cataract surgery poses a significant challenge for the cataract surgeon, in part because an elastic anterior capsule can make capsulorhexis difficult. With the use of femtosecond laser-assisted cataract surgery (FLACS), however, the continuous curvilinear capsulorhexis can be made with predictable size, circular shape, centration, and accuracy. In addition, topical anesthesia can be used for the FLACS docking procedure in cooperative children above 6 years of age, using transparent adhesive polyurethane film segments. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Disease and Surgery of the Equine Lens.

PubMed

Townsend, Wendy M

2017-12-01

Examination of the lens is critical, particularly when evaluating horses with visual impairment or performing prepurchase examinations. To adequately evaluate the lens, the pupil must be pharmacologically dilated. A cataract is any lens opacity. The size, density, and position of a cataract determine the impact on vision. Cataracts may be congenital or inherited or occur secondary to trauma or equine recurrent uveitis. Surgical removal is the only treatment option for vision impairing cataracts, but careful selection of surgical candidates is critical for successful outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Presumptive electric cataracts in a Great Horned owl (Bubo virginianus).

PubMed

Dees, D Dustin; MacLaren, Nicole E

2013-01-01

This case report describes suspected electrocution in a juvenile female Great Horned owl (Bubo virginianus) with subsequent bilateral cataract formation. The bird flew into a high-voltage power line and was immediately rescued. Burn wounds of the head and ataxia with apparent blindness were noted. Initial ophthalmic examination 5 days after the incident revealed bilaterally symmetrical anterior subcapsular vacuolar cataracts with absence of intraocular inflammation and a predominantly clear view to the normal appearing fundus. The bird appeared to be nonvisual. No ophthalmic medications were prescribed at initial examination. Subsequent recheck examination at 8 weeks revealed moderate resolution of the cataracts and improved vision. To the authors' knowledge, this is the first published report of suspected electric cataracts in an avian species. © 2012 American College of Veterinary Ophthalmologists.

[Cataract surgery and its impact on balance and autonomy in elderly].

PubMed

Raynal, M; Aupy, B; Jahidi, A; Ettien, D; Le Page, P; Briche, T; Kossowski, M; Pailllaud, E

2009-01-01

Cataract is a major cause of visual impairment among elderly. Cataract surgery improves visual afferencies and can have an impact on balance. The present study assessed the impact of cataract surgery upon balance and autonomy in elderly. We realized clinical examinations and objective tests the day before surgery and 2-months later. The initial cohort consisted of 66 patients that had to undergo a cataract surgery. Their mean age was 79 +/- 0.5. For logistic reasons, only 33 patients have been completely evaluated before and after surgery. Each patient underwent a history and examination that have assessed autonomy, walking, visual and then cochleo-vestibular functions including bone vibratory test and dynamic computerized posturography (Equitest). After 2 months, cataract surgery had no incidence on balance. The fear of falling has stayed the same whereas the number of falls has been noticeably reduced by surgery. The overall score of Equitest has shown an increase in visual dependence after surgery. Although cataract surgery has no incidence on autonomy, it may improve the quality of life among older people by leisure activities recovery. An early physical rehabilitation facilitated by visual improvement after surgery can also prevent visual dependence and autonomy loss. We recommend vestibular rehabilitation in elderly with major visual dependence.

Wavefront aberrations and retinal image quality in different lenticular opacity types and densities.

PubMed

Wu, Cheng-Zhe; Jin, Hua; Shen, Zhen-Nv; Li, Ying-Jun; Cui, Xun

2017-11-10

To investigate wavefront aberrations in the entire eye and in the internal optics (lens) and retinal image qualities according to different lenticular opacity types and densities. Forty-one eyes with nuclear cataract, 33 eyes with cortical cataract, and 29 eyes with posterior subcapsular cataract were examined. In each group, wavefront aberrations in the entire eye and in the internal optics and retinal image quality were measured using a raytracing aberrometer. Eyes with cortical cataracts showed significantly higher coma-like aberrations compared to the other two groups in both entire eye and internal optic aberrations (P = 0.012 and P = 0.007, respectively). Eyes with nuclear cataract had lower spherical-like aberrations than the other two groups in both entire eye and internal optics aberrations (P < 0.001 and P < 0.001, respectively). In the nuclear cataract group, nuclear lens density was negatively correlated with internal spherical aberrations (r = -0.527, P = 0.005). Wavefront technology is useful for objective and quantitative analysis of retinal image quality deterioration in eyes with different early lenticular opacity types and densities. Understanding the wavefront optical properties of different crystalline lens opacities may help ophthalmic surgeons determine the optimal time to perform cataract surgery.

Polyphenols of Cassia tora leaves prevents lenticular apoptosis and modulates cataract pathology in Sprague-Dawley rat pups.

PubMed

Sreelakshmi, V; Abraham, Annie

2016-07-01

Cataract is a leading cause of visual impairment worldwide with multifactorial etiology and is a significant global health problem with increasing prevalence with age. Currently, no pharmacological measures are discovered to prevent and treat cataract and a significant number of epidemiological studies have suggested the potential role of antioxidants in the prevention of cataract by scavenging free radicals and preventing lens protein derangement and lenticular cell damage. The main goal of the present study is to evaluate Cassia tora leaves; an edible leafy vegetable employed in Ayurvedic and Chinese system of medicine for eye rejuvenation in preventing selenite-induced cataract in rat pups and to identify the active components that produce the effect. ECT pre-treatment effectively restored both enzymatic and metabolic antioxidant levels, membrane integrity and reduced metal accumulation and thus down-regulate epithelial cell death. Gene expression studies also confirmed these findings. ESI-MS analysis of ECT revealed the presence of chrysophanol, emodin, kaemferol, quercetin, stigmasterol and isoquercetin. The study suggests the possible role of C. tora in alleviating cataract pathology and presence of many anthraquinones and flavonoids. As it is an edible plant, the incorporation of these leaves in daily vegetables might prevent or delay the onset and maturation of cataract. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Bilateral cataract formation via acute spontaneous fracture of the lens following treatment of hyperglycemic hyperosmolar syndrome.

PubMed

Sychev, Yevgeniy V; Zepeda, Emily M; Lam, Deborah L

2017-09-01

Acute development of cataracts that may be transient is known to occur during correction of diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome. Nettleship in 1885 was the first to describe the presence of a transient cataract in three diabetic patients that grew worse and eventually cleared with treatment. 1 We present a case of irreversible cataracts formed by nuclear fracture of the crystalline lens after hyperglycemia correction, an entity that has not yet been described. A 67 year-old Caucasian man presented with sudden bilateral vision loss one week after a week-long hospitalization in the intensive care unit for correction of hyperglycemia in the setting of hyperglycemic hyperosmolar syndrome requiring an insulin drip. This was caused by spontaneous fractures of the lens nuclei causing bilateral irreversible cataracts. The patient underwent uncomplicated bilateral cataract extraction resulting in restoration of normal vision. Acute transient cataracts that develop during correction of hyperglycemic hyperosmolar syndrome are thought to result from osmotic lens swelling. In this case report, internal fracture of the lens was produced by mechanical forces generated in the process of lens swelling occurring as a consequence of initial hyperglycemia and its subsequent correction. This case represents a rare ocular complication of hyperglycemia correction, and provides new evidence that mechanical forces can be part of diabetic cataractogenesis.

Eye healthcare services in eastern Europe: Part 1. Cataract surgery.

PubMed

Kocur, I; Resnikoff, S; Foster, A

2002-08-01

To describe cataract surgical services in 1998 in 12 eastern European countries and to identify their needs to reduce cataract blindness. All inpatient eye departments in the 12 countries received a standardised questionnaire; the data obtained were further processed at the coordinating centre in Prague. All 458 eye departments in the region were involved. The response rate was 100%, except for Bulgaria (93%) and Romania (93%). The total number of cataract surgeries per one million inhabitants in 1998 was calculated: Belarus (800), Federation of Bosnia and Herzegovina (1275), Bulgaria (1730), the Czech Republic (4210), Estonia (2530), Hungary (3530), Latvia (1860), Lithuania (1550), Trans-Dniester Moldova (1300), Poland (1475), Romania (1260), and Slovakia (2430). Cataracts were mostly operated on by the extracapsular technique. Intracapsular extractions were frequently performed in Federation of Bosnia and Herzegovina (47%), Belarus (46%), Bulgaria (18%), and Romania (14.3%). Phacoemulsification was uncommonly used in 1998, except for the Czech Republic (86%), Estonia (50%), Slovakia (38%), and Hungary (16%). An IOL was implanted in more than 90% of patients in the Czech Republic, Estonia, Hungary, Latvia, Lithuania, and Slovakia. Conditions for cataract surgery in the eastern European region differ. The main barriers to cataract surgery were state budget limitations, insufficient supply of consumables, underutilisation of operating theatres, and poor detection of patients requiring surgery.

Impact of a national system for waitlist prioritization: the experience with NIKE and cataract surgery in Sweden.

PubMed

Ng, Jonathon Q; Lundström, Mats

2014-06-01

  To evaluate waiting times for first-eye cataract surgery in Sweden following widespread adoption of the Nationell Indikationsmodell for Kataraktextraktion (NIKE) tool for prioritizing patients for cataract surgery.   Waiting times for all first-eye cataract surgeries in Sweden in 2009-2011 were identified from the Swedish National Cataract Register. Waiting times were compared according to demographic, clinical and NIKE indication group for surgery. Multivariate logistic regression modelling was used to determine factors associated with waiting times less than the 3-month Government guarantee period.   There were 141,070 first-eye cataract surgeries in 2009 to 2011; an annual increase of around 6%. Over the study period, mean waiting times decreased across all NIKE groups. The proportion waiting <3 months for surgery also increased across all NIKE groups. Surgery within 3 months of waitlisting was more likely for patients with a NIKE 1 indication classification (most need for surgery), in later years, male patients, younger patients and patients with a preoperative visual acuity in the better eye worse than 6/24.   Prioritizing patients for cataract surgery using NIKE reduces waiting times for those with the greatest need. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Influence of Corticosteroids and Vitamin E Deficiency on Onset and Cytopathology of Radiation-Induced Cataract

NASA Astrophysics Data System (ADS)

Junk, A. K.; Worgul, B. V.

Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of 72 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on regular chow. In each nutritional group 18 rats additionally received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of 6 months. Cataract onset and development were followed by weekly slit-lamp exam. After 6 month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks versus 11 wks in controls (p<0.0001)]. Corticosteroids accounted for accelerated cataract development in both irradiated (p<0.0005) and non-irradiated eyes (p<0.0001) relative to respective control eyes. Vitamin E deficiency did not affect cataract incidence in combination with radiation or steroids alone. Unexpectedly, when compared to irradiated controls, cataract development was inhibited in the group that received radiation, dexamethasone and the Vitamin E free diet (p<0.0005). Radiation, at the applied dose, was the predominant risk factor for early cataract onset. However, corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

Influence of corticosteroids and vitamin E deficiency on onset of radiation-induced cataract

NASA Astrophysics Data System (ADS)

Junk, A. K.; Worgul, B. W.

Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with, and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of seventy-two 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on standard chow. Fifty per cent of the animals in each nutritional group received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of six months. Cataract onset and development were followed by weekly slit-lamp exam. After six month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks vs. 11 wks in controls ( p < 0.0001)]. Corticosteroids accounted for accelerated cataract development in both irradiated ( p < 0.0005) and non-irradiated eyes ( p < 0.0001) relative to respective control eyes. Vitamin E deficiency did not affect cataract incidence in combination with radiation or steroids alone. Unexpectedly, when compared to irradiated controls, cataract development was inhibited in the group that received radiation, dexamethasone and the Vitamin E free diet ( p < 0.0005). Radiation, at the applied dose, was the predominant risk factor for early cataract onset. However, corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

Association of Dietary Vitamin K1 Intake With the Incidence of Cataract Surgery in an Adult Mediterranean Population

PubMed Central

Camacho-Barcia, María L.; Garcia-Gavilán, Jesús F.; Ruiz-Canela, Miguel; Corella, Dolores; Estruch, Ramón; Fitó, Montserrat; García-Layana, Alfredo; Arós, Fernando; Fiol, Miquel; Lapetra, José; Serra-Majem, Lluis; Pintó, Xavier; García-Arellano, Ana; Vinyoles, Ernest; Sorli, José Vicente; Salas-Salvadó, Jordi

2017-01-01

Importance Cataract, one of the most frequent causes of blindness in developed countries, is strongly associated with aging. The exact mechanisms underlying cataract formation are still unclear, but growing evidence suggests a potential role of inflammatory and oxidative processes. Therefore, antioxidant and anti-inflammatory factors of the diet, such as vitamin K1, could play a protective role. Objective To examine the association between dietary vitamin K1 intake and the risk of incident cataracts in an elderly Mediterranean population. Design, Setting, and Participants A prospective analysis was conducted in 5860 participants from the Prevención con Dieta Mediterránea Study, a randomized clinical trial executed between 2003 and 2011. Participants were community-dwelling men (44.2%) and women (55.8%), and the mean (SD) age was 66.3 (6.1) years. Main Outcomes and Measures Dietary vitamin K1 intake was evaluated using a validated food frequency questionnaire. The time to the cataract event was calculated as the time between recruitment and the date of the occurrence to cataract surgery, the time to the last visit of the follow-up, date of death, or the end of the study. Hazard ratios and 95% CIs for cataract incidence were estimated with a multivariable Cox proportional hazards model. Results Participants were community-dwelling men (44.2%; n = 868) and women (55.8%; n = 1086), and the mean (SD) age was 66.3 (6.1) years. After a median of 5.6 years follow-up, we documented a total of 768 new cataracts. Participants in the highest tertile of dietary vitamin K1 intake had a lower risk of cataracts than those in the lowest tertile (hazard ratio, 0.71; 95% CI, 0.58-0.88; P = .002), after adjusting for potential confounders. Conclusions and Relevance High intake of dietary vitamin K1 was associated with a reduced risk of cataracts in an elderly Mediterranean population even after adjusting by other potential confounders. Trial Registration isrctn.org: ISRCTN35739639 PMID:28494067

Genome-wide transcription analysis of histidine-related cataract in Atlantic salmon (Salmo salar L)

PubMed Central

Waagbø, Rune; Breck, Olav; Stavrum, Anne-Kristin; Petersen, Kjell; Olsvik, Pål A.

2009-01-01

Purpose Elevated levels of dietary histidine have previously been shown to prevent or mitigate cataract formation in farmed Atlantic salmon (Salmo salar L). The aim of this study was to shed light on the mechanisms by which histidine acts. Applying microarray analysis to the lens transcriptome, we screened for differentially expressed genes in search for a model explaining cataract development in Atlantic salmon and possible markers for early cataract diagnosis. Methods Adult Atlantic salmon (1.7 kg) were fed three standard commercial salmon diets only differing in the histidine content (9, 13, and 17 g histidine/kg diet) for four months. Individual cataract scores for both eyes were assessed by slit-lamp biomicroscopy. Lens N-acetyl histidine contents were measured by high performance liquid chromatography (HPLC). Total RNA extracted from whole lenses was analyzed using the GRASP 16K salmonid microarray. The microarray data were analyzed using J-Express Pro 2.7 and validated by quantitative real-time polymerase chain reaction (qRT–PCR). Results Fish developed cataracts with different severity in response to dietary histidine levels. Lens N-acetyl histidine contents reflected the dietary histidine levels and were negatively correlated to cataract scores. Significance analysis of microarrays (SAM) revealed 248 significantly up-regulated transcripts and 266 significantly down-regulated transcripts in fish that were fed a low level of histidine compared to fish fed a higher histidine level. Among the differentially expressed transcripts were metallothionein A and B as well as transcripts involved in lipid metabolism, carbohydrate metabolism, regulation of ion homeostasis, and protein degradation. Hierarchical clustering and correspondence analysis plot confirmed differences in gene expression between the feeding groups. The differentially expressed genes could be categorized as “early” and “late” responsive according to their expression pattern relative to progression in cataract formation. Conclusions Dietary histidine regimes affected cataract formation and lens gene expression in adult Atlantic salmon. Regulated transcripts selected from the results of this genome-wide transcription analysis might be used as possible biological markers for cataract development in Atlantic salmon. PMID:19597568

The Claim of Anti-Cataract Potential of Heliotropium indicum: A Myth or Reality?

PubMed

Kyei, Samuel; Koffuor, George Asumeng; Ramkissoon, Paul; Afari, Clement; Asiamah, Emmanuel Akomanin

2015-12-01

Heliotropium indicum has several uses in traditional medicine attributable to its numerous bioactive compounds. It is used as a traditional remedy for cataracts in Ghana without any scientific verification. This study aimed at verifying the anti-cataract properties of an aqueous whole plant extract of H. indicum. The effect (cataract score) of 30, 100, and 300 mg kg(-1) extract (bid for 21 days, per os) on the development of 30 µmol kg(-1) sodium selenite-induced cataract in 10-day-old rat pups was investigated. Soluble lens proteins alpha A and alpha B crystallins, total lens protein, total lens glutathione, and aquaporin 0 in enucleated lens homogenates were determined spectrophotometrically using commercially available kits. Histopathological studies on the lenses were also performed. The 2,2-diphenyl-1-picrylhydrazyl scavenging effect and linoleic acid autoxidation (antioxidant properties) of the extract (0.1-3.0 mg ml(-1)), compared to n-propyl gallate, were ascertained using standard procedures. Cataract scores showed that the extract, at all dose levels, significantly alleviated selenite-induced cataracts (P ≤ 0.001). Markers of lens transparency (aquaporin 0, alpha A and B crystallins), as well as total lens proteins and lens glutathione levels, were significantly preserved (P ≤ 0.01-0.001). The extract exhibited activity relevant for scavenging free radicals and inhibition of lipid peroxidation. Epithelial and lens fiber integrity in the histopathological assessment were maintained with HIE treatment. The aqueous whole plant extract of H. indicum significantly inhibited the development of cataracts in rats via multiple mechanisms.

The carbon footprint of cataract surgery.

PubMed

Morris, D S; Wright, T; Somner, J E A; Connor, A

2013-04-01

Climate change is predicted to be one of the largest global health threats of the 21st century. Health care itself is a large contributor to carbon emissions. Determining the carbon footprint of specific health care activities such as cataract surgery allows the assessment of associated emissions and identifies opportunities for reduction. To assess the carbon footprint of a cataract pathway in a British teaching hospital. This was a component analysis study for one patient having first eye cataract surgery in the University Hospital of Wales, Cardiff. Activity data was collected from three sectors, building and energy use, travel and procurement. Published emissions factors were applied to this data to provide figures in carbon dioxide equivalents (CO2eq). The carbon footprint for one cataract operation was 181.8 kg CO2eq. On the basis that 2230 patients were treated for cataracts during 2011 in Cardiff, this has an associated carbon footprint of 405.4 tonnes CO2eq. Building and energy use was estimated to account for 36.1% of overall emissions, travel 10.1% and procurement 53.8%, with medical equipment accounting for the most emissions at 32.6%. This is the first published carbon footprint of cataract surgery and acts as a benchmark for other studies as well as identifying areas for emissions reduction. Within the procurement sector, dialogue with industry is important to reduce the overall carbon footprint. Sustainability should be considered when cataract pathways are designed as there is potential for reduction in all sectors with the possible side effects of saving costs and improving patient care.

The carbon footprint of cataract surgery

PubMed Central

Morris, D S; Wright, T; Somner, J E A; Connor, A

2013-01-01

Background Climate change is predicted to be one of the largest global health threats of the 21st century. Health care itself is a large contributor to carbon emissions. Determining the carbon footprint of specific health care activities such as cataract surgery allows the assessment of associated emissions and identifies opportunities for reduction. Aim To assess the carbon footprint of a cataract pathway in a British teaching hospital. Methods This was a component analysis study for one patient having first eye cataract surgery in the University Hospital of Wales, Cardiff. Activity data was collected from three sectors, building and energy use, travel and procurement. Published emissions factors were applied to this data to provide figures in carbon dioxide equivalents (CO2eq). Results The carbon footprint for one cataract operation was 181.8 kg CO2eq. On the basis that 2230 patients were treated for cataracts during 2011 in Cardiff, this has an associated carbon footprint of 405.4 tonnes CO2eq. Building and energy use was estimated to account for 36.1% of overall emissions, travel 10.1% and procurement 53.8%, with medical equipment accounting for the most emissions at 32.6%. Conclusions This is the first published carbon footprint of cataract surgery and acts as a benchmark for other studies as well as identifying areas for emissions reduction. Within the procurement sector, dialogue with industry is important to reduce the overall carbon footprint. Sustainability should be considered when cataract pathways are designed as there is potential for reduction in all sectors with the possible side effects of saving costs and improving patient care. PMID:23429413

Cataract Avoidance With Proton Therapy in Ocular Melanomas.

PubMed

Thariat, Juliette; Jacob, Sophie; Caujolle, Jean-Pierre; Maschi, Celia; Baillif, Stéphanie; Angellier, Gaelle; Mathis, Thibaud; Rosier, Laurence; Carnicer, Adela; Hérault, Joel; Salleron, Julia

2017-10-01

The lens is a radiosensitive organ. Any dose of cephalic irradiation can give rise to radiation-induced cataracts. Contrary to other forms of radiotherapy, proton therapy (PT) can spare all or part of the lens due to accurate dose deposition. We investigated whether a lens-sparing approach was relevant to avoid cataracts in uveal melanoma patients. Patients were referred for PT from onco-ophthalmologists of private and academic institutions. Patients without preexisting cataracts or implants were entered in a prospective database. Dose thresholds responsible for cataracts were investigated in volumes of lens or lens periphery. Lens opacifications and de novo vision-impairing cataracts (VICs) had biannual follow up by ophthalmologists blinded to lens dose. Correlations between dose-volume relationships and VICs were assessed using univariate/multivariate regressions. Between 1991 and 2015, 1696 uveal melanoma patients were consecutively treated with PT. After a median follow up of 48 months, 14.4% and 8.7% of patients had cataracts and VIC within median times of 19 and 28 months, respectively. Median values of mean lens and lens periphery doses were 1.1 (radiobiologically effective [RBE] dose in photon-equivalent grays [GyRBE]) and 6.5 GyRBE, respectively. The lens received no dose in 25% of the patients. At an irradiated lens volume of ≤5%, there was no significantly increased risk for VIC below a dose of 10 GyRBE. A lens-sparing approach is feasible and results not only in reduced need for cataract surgery but also in better fundus-based tumor control. Reassessment of radioprotection rules for lens dose thresholds may follow.

Importance of multi-modal approaches to effectively identify cataract cases from electronic health records

PubMed Central

Rasmussen, Luke V; Berg, Richard L; Linneman, James G; McCarty, Catherine A; Waudby, Carol; Chen, Lin; Denny, Joshua C; Wilke, Russell A; Pathak, Jyotishman; Carrell, David; Kho, Abel N; Starren, Justin B

2012-01-01

Objective There is increasing interest in using electronic health records (EHRs) to identify subjects for genomic association studies, due in part to the availability of large amounts of clinical data and the expected cost efficiencies of subject identification. We describe the construction and validation of an EHR-based algorithm to identify subjects with age-related cataracts. Materials and methods We used a multi-modal strategy consisting of structured database querying, natural language processing on free-text documents, and optical character recognition on scanned clinical images to identify cataract subjects and related cataract attributes. Extensive validation on 3657 subjects compared the multi-modal results to manual chart review. The algorithm was also implemented at participating electronic MEdical Records and GEnomics (eMERGE) institutions. Results An EHR-based cataract phenotyping algorithm was successfully developed and validated, resulting in positive predictive values (PPVs) >95%. The multi-modal approach increased the identification of cataract subject attributes by a factor of three compared to single-mode approaches while maintaining high PPV. Components of the cataract algorithm were successfully deployed at three other institutions with similar accuracy. Discussion A multi-modal strategy incorporating optical character recognition and natural language processing may increase the number of cases identified while maintaining similar PPVs. Such algorithms, however, require that the needed information be embedded within clinical documents. Conclusion We have demonstrated that algorithms to identify and characterize cataracts can be developed utilizing data collected via the EHR. These algorithms provide a high level of accuracy even when implemented across multiple EHRs and institutional boundaries. PMID:22319176

[Determining factors for deciding whether or not to treat refractive errors and cataract in people with a learning disability].

PubMed

van Isterdael, C E D; Stilma, J S; Bezemer, P D; Tijmes, N T

2008-05-03

A study into the treatment of refractive errors and cataract in a selected population with learning disabilities. Design. Retrospective. In the years 1993-2003, 5205 people (mean age: 39 years) were referred to the visual advisory centre of Bartiméus (one of three institutes for the visually impaired in the Netherlands) by learning disability physicians and were assessed ophthalmologically. This assessment consisted of a measurement of visual acuity and refractive error, slitlamp examination and retinoscopy, and was performed at the client's accommodation. Advised treatment for spectacle prescriptions and referral for cataract surgery were registered. Refractive errors were found in 35% (1845/5205) of the patients with learning disabilities; 49% (905/1845) already wore spectacles; another 14% (265/1845) were prescribed spectacles for the first time. Of those with presbyopia, 12% (232/1865) had reading glasses and 10% (181/1865) were given a first prescription for spectacles. The most important determinant for not prescribing spectacles was: presence of severe learning disability (odds ratio (OR): 3.7). Cataract was present in 10% (497/5205) of the population; 399 patients were advised to be referred for surgery, 55% (219/399) were referred ofwhom 26% (57/219) had surgery. Moderately severe bilateral cataract was the only determinant of cataract surgery (OR: 7.8). Refractive errors and cataract were not always treated in this group. One of the reasons for non-treatment of refractive errors was a severe learning disability. The reason for treatment or non-treatment in patients with cataract was less clear.

YouTube videos in the English language as a patient education resource for cataract surgery.

PubMed

Bae, Steven S; Baxter, Stephanie

2017-08-28

To assess the quality of the content of YouTube videos for cataract surgery patient education. Hotel Dieu Hospital, Kingston, Ontario, Canada. Observational study. "Cataract surgery," "cataract surgery for patients," and "cataract surgery patient education" were used as search terms. The first two pages of search results were reviewed. Descriptive statistics such as video length and view count were obtained. Two cataract surgeons devised 14 criteria important for educating patients about the procedure. Videos were analyzed based on the presence or absence of these criteria. Videos were also assessed for whether they had a primary commercial intent. Seventy-two videos were analyzed after excluding 48 videos that were duplicate, irrelevant, or not in English. The majority of videos came from a medical professional (71%) and many depicted a real cataract surgery procedure (43%). Twenty-one percent of the videos had a primary commercial intent to promote a practice or product. Out of a total possible 14 points, the mean number of usefulness criteria satisfied was only 2.28 ± 1.80. There was no significant difference in view count between the most useful videos and other videos (p = 0.94). Videos from medical organizations such as the National Health Service were more useful (p < 0.0001). Cataract surgery videos are popular on YouTube, but most are not adequately educational. Patients may be receiving biased information from videos created with primary commercial intent. Physicians should be aware of the type of information patients may be accessing on YouTube.

Methods for assessing forward and backward light scatter in patients with cataract.

PubMed

Crnej, Alja; Hirnschall, Nino; Petsoglou, Con; Findl, Oliver

2017-08-01

To compare objective methods for assessing backward and forward light scatter and psychophysical tests in patients with cataracts. Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. Prospective case series. This study included patients scheduled for cataract surgery. Lens opacities were grouped into predominantly nuclear sclerotic, cortical, posterior subcapsular, and mixed cataracts. Backward light scatter was assessed using a rotating Scheimpflug imaging technique (Pentacam HR), forward light scatter using a straylight meter (C-Quant), and straylight using the double-pass method (Optical Quality Analysis System, point-spread function [PSF] meter). The results were correlated with visual acuity under photopic conditions as well as photopic and mesopic contrast sensitivity. The study comprised 56 eyes of 56 patients. The mean age of the 23 men and 33 women was 71 years (range 48 to 84 years). Two patients were excluded. Of the remaining, 15 patients had predominantly nuclear sclerotic cataracts, 13 had cortical cataracts, 11 had posterior subcapsular cataracts, and 15 had mixed cataracts. Correlations between devices were low. The highest correlation was between PSF meter measurements and Scheimpflug measurements (r = 0.32). The best correlation between corrected distance visual acuity was with the PSF meter (r = 0.45). Forward and backward light-scatter measurements cannot be used interchangeably. Scatter as an aspect of quality of vision was independent of acuity. Measuring forward light scatter with the straylight meter can be a useful additional tool in preoperative decision-making. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Influence of cataract surgery on optical coherence tomography and neurophysiology measurements in patients with retinitis pigmentosa.

PubMed

Garcia-Martin, Elena; Rodriguez-Mena, Diego; Dolz, Isabel; Almarcegui, Carmen; Gil-Arribas, Laura; Bambo, Maria P; Larrosa, Jose M; Polo, Vicente; Pablo, Luis E

2013-08-01

To evaluate the effect of uncomplicated cataract phacoemulsification on the measurements of visual evoked potentials (VEP), pattern electroretinogram (PERG), and macular and retinal nerve fiber layer (RNFL) using 2 spectral-domain optical coherence tomography (OCT) instruments, the Cirrus OCT (Carl Zeiss Meditech) and Spectralis OCT (Heidelberg Engineering), in patients with retinitis pigmentosa (RP), and to assess the reliability of the OCT measurements before and after cataract surgery. Observational cross-sectional study. Thirty-five eyes of 35 patients with RP (20 men and 15 women, 45-66 years) who underwent cataract phacoemulsification were studied. At 1 month before and 1 month after surgery, visual acuity, VEP, PERG, and 3 repetitions of scans using the RNFL and macular analysis protocols of the Cirrus and Spectralis OCT instruments were performed. The differences in measurements between the 2 visits were analyzed. Repeatability of OCT measurements was evaluated by calculating the coefficients of variation. VEP amplitude, RNFL thicknesses provided by Cirrus and Spectralis, and macular measurements provided by Cirrus OCT differed between the 2 visits. VEP latency, PERG measurements, and macular thicknesses provided by the Spectralis OCT before surgery did not differ significantly from those after surgery. The OCT repeatability was better after surgery, with lower coefficients of variation for scans performed after surgical removal of the cataract. The nuclear, cortical, and posterior subcapsular types of cataracts did not show different repeatability. The presence of cataracts affects VEP amplitude, RNFL, and macular measurements performed with OCT in eyes with RP. Image repeatability significantly improves after cataract phacoemulsification. Copyright © 2013 Elsevier Inc. All rights reserved.

Age and Smoking Related Changes in Metal Ion Levels in Human Lens: Implications for Cataract Formation

PubMed Central

Langford-Smith, Alex; Tilakaratna, Viranga; Lythgoe, Paul R.; Clark, Simon J.; Bishop, Paul N.; Day, Anthony J.

2016-01-01

Age-related cataract formation is the primary cause of blindness worldwide and although treatable by surgical removal of the lens the majority of sufferers have neither the finances nor access to the medical facilities required. Therefore, a better understanding of the pathogenesis of cataract may identify new therapeutic targets to prevent or slow its progression. Cataract incidence is strongly correlated with age and cigarette smoking, factors that are often associated with accumulation of metal ions in other tissues. Therefore this study evaluated the age-related changes in 14 metal ions in 32 post mortem human lenses without known cataract from donors of 11 to 82 years of age by inductively coupled plasma mass spectrometry; smoking-related changes in 10 smokers verses 14 non-smokers were also analysed. A significant age-related increase in selenium and decrease in copper ions was observed for the first time in the lens tissue, where cadmium ion levels were also increased as has been seen previously. Aluminium and vanadium ions were found to be increased in smokers compared to non-smokers (an analysis that has only been carried out before in lenses with cataract). These changes in metal ions, i.e. that occur as a consequence of normal ageing and of smoking, could contribute to cataract formation via induction of oxidative stress pathways, modulation of extracellular matrix structure/function and cellular toxicity. Thus, this study has identified novel changes in metal ions in human lens that could potentially drive the pathology of cataract formation. PMID:26794210

Secondary glaucoma after pediatric cataract surgery

PubMed Central

Şahin, Alparslan; Çaça, Ihsan; Cingü, Abdullah Kürşat; Türkcü, Fatih Mehmet; Yüksel, Harun; Şahin, Muhammed; Çinar, Yasin; Ari, Şeyhmus

2013-01-01

AIM To determine the incidence and risk factors of secondary glaucoma after pediatric cataract surgery. METHODS Two hundred and forty nine eyes of 148 patients underwent cataract surgery without intraocular lens (IOL) implantation (group 1), and 220 eyes of 129 patients underwent cataract surgery with IOL implantation (group 2) retrospectively, were evaluated between 2000 and 2011. The outcome measure was the presence or absence of post-cataract surgery glaucoma, defined as an intraocular pressure (IOP) ≥26mmHg, as measured on at least two occasions along with corneal or optic nerve changes. RESULTS The mean follow-up periods of group 1 and 2 were (60.86±30.95) months (12-123 months) and (62.11±31.29) months (14-115 months) respectively. In group 1, 12 eyes of 8 patients (4.8%) developed glaucoma. None of the patients developed glaucoma after surgery in group 2. The mean age of the patients at the cataract surgery was (2.58±0.90) months (1 month-4 months) and the average period for glaucoma development after surgery was (9.50±4.33) months (4-16 months) in group 1. Three of the 12 glaucomatous eyes were controlled with antiglaucomatous medication and 9 eyes underwent trabeculectomy+mitomycin C surgery. One patient underwent a second trabeculectomy + mitomycin C operation for both of his eyes. CONCLUSION The incidence of glaucoma after pediatric cataract surgery is very low in patients in whom IOL is implanted. The aphakic eyes after pediatric cataract surgery are at an increased risk for glaucoma development particularly if they underwent surgery before 4 months of age. PMID:23638427

Visual outcomes of phacoemulsification cataract surgery in horses: 1990-2013.

PubMed

Brooks, Dennis E; Plummer, Caryn E; Carastro, Susan M; Utter, Mary E

2014-07-01

To evaluate the long-term visual outcome of phacoemulsification lens extraction surgery in foals and horses and identify any unique postoperative complications that affect the visual outcome. This is a retrospective medical records study of phacoemulsification cataract surgery in 95 foals and horses from 1990 to 2013. Cataracts were removed by phacoemulsification from 111 eyes of 95 horses ranging in age from 22 days to 26 years (average 8.0 ± 5.7 years). Forty-four of the 95 animals were foals (46.3%). Sixteen horses or foals had surgery bilaterally. One hundred and two eyes were blind preoperatively with 97 eyes (95.1%) having evidence of vision immediately postoperatively. Ninety of the 95 horses (94.7%) regained vision in the immediate postoperative period. Five horses did not recover vision postoperatively. Twenty-four horses had cataracts associated with equine recurrent uveitis (ERU). Trauma was noted as the cause of cataract in 10 horses, and no specific cause for the cataract identified in 61 horses. The combined visual outcome data from horses with all types of cataracts (n = 95) found 83 (87.3%) horses to be visual ≤1 month postoperatively, 47 (49.4%) horses visual for >1-6 months postoperatively, 33 (34.7%) horses visual from >6 to 12 months postoperatively, and 25 horses (26.3%) visual >24 months postoperatively. The results of phacoemulsification cataract surgery in horses indicate at least 26.3% of horses are still visual and able to continue their natural activity for 2 years or more postoperatively. © 2014 American College of Veterinary Ophthalmologists.

Outcomes of cataract surgery in patients with exudative age-related macular degeneration and macular fluid.

PubMed

Starr, Matthew R; Mahr, Michael A; Barkmeier, Andrew J; Iezzi, Raymond; Smith, Wendy M; Bakri, Sophie J

2018-05-23

The purpose of this study was to investigate whether having macular fluid on the OCT prior to cataract surgery adversely affected vision or anatomic outcomes after cataract surgery in patients with exudative AMD. Retrospective, cohort study. We examined all patients who underwent cataract surgery and were receiving intravitreal anti-VEGF injections from January 1 st , 2012 through December 31 st , 2016. There were 81 eyes that underwent cataract surgery and had received at least one intravitreal anti-VEGF injection for a diagnosis of exudative AMD within 6 months prior to surgery. Data collected included the development of subretinal or intraretinal macular fluid, or subretinal hemorrhage in the 6 months following surgery, number of injections, best corrected visual acuity (BCVA), and central subfield thickness (CST). There was a significant improvement between pre- and post-operative BCVA when comparing all patients (p values <0.0001) and no significant difference in CST before and after surgery (p >0.05). There were 23 eyes with fluid on the pre-operative OCT. There were no differences in final BCVA or CST and no difference in the development of fluid post-operatively when compared to patients without fluid pre-operatively (all p values >0.05). These patients also saw a significant improvement in BCVA (p = 0.006). In a real world setting, patients with both cataracts and wet AMD may safely undergo cataract surgery. Patients with stable pre-operative fluid on OCT should be considered for cataract surgery as these patients did well post-operatively with no worsening of their neovascular process. Copyright © 2018. Published by Elsevier Inc.

Operational Based Vision Assessment Research: Depth Perception

DTIC Science & Technology

2014-11-01

13-072 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) USAF School of Aerospace Medicine...Aeromedical Research Department 2510 Fifth St. Wright-Patterson AFB, OH 45433-7913 8. PERFORMING ORGANIZATION REPORT NUMBER AFRL-SA-WP-JA-2014...tests are tests of stereopsis, such as the AFVT and AO Vectograph. Others evaluate depth perception with stereo as a contributor to performance , such

Transcranial direct current stimulation enhances recovery of stereopsis in adults with amblyopia.

PubMed

Spiegel, Daniel P; Li, Jinrong; Hess, Robert F; Byblow, Winston D; Deng, Daming; Yu, Minbin; Thompson, Benjamin

2013-10-01

Amblyopia is a neurodevelopmental disorder of vision caused by abnormal visual experience during early childhood that is often considered to be untreatable in adulthood. Recently, it has been shown that a novel dichoptic videogame-based treatment for amblyopia can improve visual function in adult patients, at least in part, by reducing inhibition of inputs from the amblyopic eye to the visual cortex. Non-invasive anodal transcranial direct current stimulation has been shown to reduce the activity of inhibitory cortical interneurons when applied to the primary motor or visual cortex. In this double-blind, sham-controlled cross-over study we tested the hypothesis that anodal transcranial direct current stimulation of the visual cortex would enhance the therapeutic effects of dichoptic videogame-based treatment. A homogeneous group of 16 young adults (mean age 22.1 ± 1.1 years) with amblyopia were studied to compare the effect of dichoptic treatment alone and dichoptic treatment combined with visual cortex direct current stimulation on measures of binocular (stereopsis) and monocular (visual acuity) visual function. The combined treatment led to greater improvements in stereoacuity than dichoptic treatment alone, indicating that direct current stimulation of the visual cortex boosts the efficacy of dichoptic videogame-based treatment. This intervention warrants further evaluation as a novel therapeutic approach for adults with amblyopia.

Stereopsis, vertical disparity and relief transformations.

PubMed

Gårding, J; Porrill, J; Mayhew, J E; Frisby, J P

1995-03-01

The pattern of retinal binocular disparities acquired by a fixating visual system depends on both the depth structure of the scene and the viewing geometry. This paper treats the problem of interpreting the disparity pattern in terms of scene structure without relying on estimates of fixation position from eye movement control and proprioception mechanisms. We propose a sequential decomposition of this interpretation process into disparity correction, which is used to compute three-dimensional structure up to a relief transformation, and disparity normalization, which is used to resolve the relief ambiguity to obtain metric structure. We point out that the disparity normalization stage can often be omitted, since relief transformations preserve important properties such as depth ordering and coplanarity. Based on this framework we analyse three previously proposed computational models of disparity processing; the Mayhew and Longuet-Higgins model, the deformation model and the polar angle disparity model. We show how these models are related, and argue that none of them can account satisfactorily for available psychophysical data. We therefore propose an alternative model, regional disparity correction. Using this model we derive predictions for a number of experiments based on vertical disparity manipulations, and compare them to available experimental data. The paper is concluded with a summary and a discussion of the possible architectures and mechanisms underling stereopsis in the human visual system.

Vision Training Methods for Sports Concussion Mitigation and Management

PubMed Central

Clark, Joseph F.; Colosimo, Angelo; Ellis, James K.; Mangine, Robert; Bixenmann, Benjamin; Hasselfeld, Kimberly; Graman, Patricia; Elgendy, Hagar; Myer, Gregory; Divine, Jon

2015-01-01

There is emerging evidence supporting the use vision training, including light board training tools, as a concussion baseline and neuro-diagnostic tool and potentially as a supportive component to concussion prevention strategies. This paper is focused on providing detailed methods for select vision training tools and reporting normative data for comparison when vision training is a part of a sports management program. The overall program includes standard vision training methods including tachistoscope, Brock’s string, and strobe glasses, as well as specialized light board training algorithms. Stereopsis is measured as a means to monitor vision training affects. In addition, quantitative results for vision training methods as well as baseline and post-testing *A and Reaction Test measures with progressive scores are reported. Collegiate athletes consistently improve after six weeks of training in their stereopsis, *A and Reaction Test scores. When vision training is initiated as a team wide exercise, the incidence of concussion decreases in players who participate in training compared to players who do not receive the vision training. Vision training produces functional and performance changes that, when monitored, can be used to assess the success of the vision training and can be initiated as part of a sports medical intervention for concussion prevention. PMID:25992878

[Binocular functions in amblyopia and strabismus].

PubMed

Awaya, S; Sato, M; Tsuzuki, K; Takara, T; Hiraiwa, S; Ota, K; Arai, M; Yoshida, M; Miyake, Y; Terasaki, H; Horiguchi, M; Hirano, K; Hirose, H; Uno, Y; Suzuki, Y; Iwata, M; Takai, Y; Maeda, M; Hisano, S; Kawakita, T; Omura, T; Ota, Y; Kondo, N; Takashi, A; Kawakami, O

1997-12-01

Regarding the changing trends in the concept, definition, etiological classification, and criteria for diagnosis of amblyopia, we reviewed a total of 4,693 cases of amblyopia seen during the past 37 years. The amblyopia was divided into four types: strabismic, anisometropic, ametropic, and form vision deprivative. There was a definite trend for the incidence to decrease and for the diagnosis to be made during earlier age in recent years. Although favorable recovery of visual acuity is obtained after treatment of amblyopia and strabismus, there are difficulties in obtaining good binocular functions in early-onset amblyopia and strabismus. This feature was evaluated in regard to motion perception asymmetry (MPA) and binocular depth from motion (DFM). Many cases of early-onset amblyopia and strabismus showed no disparity stereopsis, or position stereopsis, in spite of the presence of DFM. The MPA appeared to be closely related to early-onset esotropia regardless of age, while it disappeared and motion perception became symmetric 4 to 5 months after birth in normal infants. The DFM seemed to play an important role in maintaining good motor alignment for several years after surgery. I developed a checkerboard pattern stimulator in 1978. This method proved to be useful in developing binocular functions and motor alignment by applying simultaneous bifoveolar stimulation and anti-suppression. Extensive exposure to the stimulation was essential for therapeutic success.

Image-size differences worsen stereopsis independent of eye position

PubMed Central

Vlaskamp, Björn N. S.; Filippini, Heather R.; Banks, Martin S.

2010-01-01

With the eyes in forward gaze, stereo performance worsens when one eye’s image is larger than the other’s. Near, eccentric objects naturally create retinal images of different sizes. Does this mean that stereopsis exhibits deficits for such stimuli? Or does the visual system compensate for the predictable image-size differences? To answer this, we measured discrimination of a disparity-defined shape for different relative image sizes. We did so for different gaze directions, some compatible with the image-size difference and some not. Magnifications of 10–15% caused a clear worsening of stereo performance. The worsening was determined only by relative image size and not by eye position. This shows that no neural compensation for image-size differences accompanies eye-position changes, at least prior to disparity estimation. We also found that a local cross-correlation model for disparity estimation performs like humans in the same task, suggesting that the decrease in stereo performance due to image-size differences is a byproduct of the disparity-estimation method. Finally, we looked for compensation in an observer who has constantly different image sizes due to differing eye lengths. She performed best when the presented images were roughly the same size, indicating that she has compensated for the persistent image-size difference. PMID:19271927

Outcome of cataract surgery following simple limbal epithelial transplantation for lime injury-induced limbal stem cell deficiency

PubMed Central

Nair, Dhanyasree

2015-01-01

A 19-year-old woman presented to us after being diagnosed elsewhere with right eye total limbal stem cell deficiency resulting from a lime burn. She was advised to undergo limbal stem cell transplantation, but failed to immediately do so. Two years later, she underwent cultivated limbal epithelial transplantation (CLET). As she had severe loss of vision with persisting conjunctival nodule and symblepharon 2 years following surgery, an impression of failed CLET was formed. Subsequently, simple limbal epithelial transplantation (SLET) was performed. Nine months later, she developed a cataract in her right eye; the cataract was extracted and posterior chamber intraocular lens implanted. The unaided visual acuity improved from light perception at presentation to 20/60 at 1-week postoperatively. At 5 months follow-up, the patient continued to maintain 20/60 visual acuity in her right eye. This case describes the outcome of cataract surgery following SLET, emphasising the need to perform cataract surgery in complicated cataracts for a better visual prognosis. PMID:26698204

Use of non-subjective analysis of lens transparency in experimental radiation cataract research

NASA Technical Reports Server (NTRS)

Worgul, B. V.; Medvedovsky, C.; Wu, B.

1995-01-01

Historically the major impediment to radiation cataract follow-up has been the necessarily subjective nature of assessing the degree of lens transparency. This has spurred the development of instruments which produce video images amenable to digital analysis. One such system, the Zeiss Scheimpflug slit lamp measuring system (SLC), was incorporated into our ongoing studies of radiation cataractogenesis. It was found that the Zeiss SLC measuring system has high resolution and permits the acquisition of reproducible images of the anterior segment of the eye. Our results, based on about 650 images of lenses followed over a period of 91 weeks of radiation cataract development, showed that the changes in the light scatter of the lens correlated well with conventional assessment of radiation cataracts with the added advantages of objectivity, permanent and transportable records and linearity as cataracts become more severe. This continuous data acquisition, commencing with cataract onset, can proceed through more advanced stages. The SLC exhibits much greater sensitivity reflected in a continuously progressive severity thereby avoiding the artifactual plateaus in staging which occur using conventional scoring methods.

Mapping of the X-linked cataract (Xcat) mutation, the gene implicated in the Nance Horan syndrome, on the mouse X chromosome.

PubMed

Stambolian, D; Favor, J; Silvers, W; Avner, P; Chapman, V; Zhou, E

1994-07-15

The Xcat mutation in the mouse, an X-linked inherited disorder, is characterized by the congenital onset of cataracts. The cataracts have morphologies similar to those of cataracts found in the human Nance Horan (X-linked cataract dental) syndrome, suggesting that Xcat is an animal model for Nance Horan. The Xcat mutation provides an opportunity to investigate, at the molecular level, the pathogenesis of cataract. As a first step to cloning the Xcat gene, we report the localization of the Xcat mutation with respect to known molecular markers on the mouse X chromosome. Back-cross progeny carrying the Xcat mutation were obtained from an interspecific cross. Genomic DNA from each mouse was subjected to Southern and PCR analysis to identify restriction fragment length polymorphisms and simple sequence length polymorphisms, respectively. Our results refine the location of Xcat to a 2-cM region, eliminate several genes from consideration as the Xcat mutation, identify molecular probes tightly linked with Xcat, and suggest candidate genes responsible for the Xcat phenotype.

Infectious agents in congenital cataract in a tertiary care referral center in North India.

PubMed

Singh, Mini P; Ram, Jagat; Kumar, Archit; Khurana, Jasmine; Marbaniang, Merinda; Ratho, Radha Kanta

2016-08-01

Congenital cataract has the potential for inhibiting early visual development. Intrauterine infections with Rubella virus, Herpes simplex virus (HSV) and Toxoplasma gondii plays an important role in the development of congenital cataract. The study included 120 children under the age of 6 years presenting with congenital cataract and diagnosed using serology and polymerase chain reaction (PCR). The IgM positivity for rubella, HSV, T. gondii was found to be 5.8%, 1.6% and 8.3% respectively. The overall PCR positivity was found to be 40(33.3%), 25 (20.8%) and 39 (32.5%) for rubella, HSV and T. gondii with mean copy number of 1599 copies/μL; 1716 copies/μL and 1503 copies/μL respectively. Infective etiology significantly contributes to the causation of congenital cataract particularly for rubella virus which is a potentially eradicable disease. This study provides an epidemiological data for rubella, HSV and T. gondii in children with congenital cataract and highlights the need to introduce rubella vaccine in the National Immunization Programme of India. Copyright © 2016 Elsevier Inc. All rights reserved.

Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract

PubMed Central

Mathew, Milan C; Ervin, Ann-Margret; Tao, Jeremiah; Davis, Richard M

2013-01-01

Background Age-related cataract is a major cause of visual impairment in the elderly. Oxidative stress has been implicated in its formation and progression. Antioxidant vitamin supplementation has been investigated in this context. Objectives To assess the effectiveness of antioxidant vitamin supplementation in preventing and slowing the progression of age-related cataract. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to March 2012), EMBASE (January 1980 to March 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 2 March 2012. We also checked the reference lists of included studies and ongoing trials and contacted investigators to identify eligible randomized trials. Selection criteria We included only randomized controlled trials in which supplementation with one or more antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in any form, dosage or combination for at least one year was compared to another antioxidant vitamin or to placebo. Data collection and analysis Two authors extracted data and assessed trial quality independently. We pooled results for the primary outcomes, i.e., incidence of cataract and incidence of cataract extraction. We did not pool results of the secondary outcomes - progression of cataract and loss of visual acuity, because of differences in definitions of outcomes and data presentation. We pooled results by type of cataract when data were available. We did not perform a sensitivity analysis. Main results Nine trials involving 117,272 individuals of age 35 years or older are included in this review. The trials were conducted in Australia, Finland, India, Italy, the United Kingdom and the United States, with duration of follow-up ranging from 2.1 to 12 years. The doses of antioxidant vitamins were higher than the recommended daily allowance. There was no evidence of effect of antioxidant vitamin supplementation in reducing the risk of cataract, cataract extraction, progression of cataract or in slowing the loss of visual acuity. In the pooled analyses, there was no evidence of effect of beta-carotene supplementation in reducing the risk of cataract (two trials) (relative risk (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.08; n = 57,703) or in reducing the risk of cataract extraction (three trials) (RR 1.00, 95% CI 0.91 to 1.10; n = 86,836) or of vitamin E supplementation in reducing the risk of cataract (three trials) (RR 0.97, 95% CI 0.91 to 1.04; n = 50,059) or of cataract extraction (five trials) (RR 0.98, 95% CI 0.91 to 1.05; n = 83,956). The proportion of participants developing hypercarotenodermia (yellowing of skin) while on beta-carotene ranged from 7.4% to 15.8%. Authors’ conclusions There is no evidence from RCTs that supplementation with antioxidant vitamins (beta-carotene, vitamin C or vitamin E) prevents or slows the progression of age-related cataract. We do not recommend any further studies to examine the role of antioxidant vitamins beta-carotene, vitamin C and vitamin E in preventing or slowing the progression of age-related cataract. Costs and adverse effects should be weighed carefully with unproven benefits before recommending their intake above recommended daily allowances. PMID:22696344

Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract.

PubMed

Mathew, Milan C; Ervin, Ann-Margret; Tao, Jeremiah; Davis, Richard M

2012-06-13

Age-related cataract is a major cause of visual impairment in the elderly. Oxidative stress has been implicated in its formation and progression. Antioxidant vitamin supplementation has been investigated in this context. To assess the effectiveness of antioxidant vitamin supplementation in preventing and slowing the progression of age-related cataract. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to March 2012), EMBASE (January 1980 to March 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 2 March 2012. We also checked the reference lists of included studies and ongoing trials and contacted investigators to identify eligible randomized trials. We included only randomized controlled trials in which supplementation with one or more antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in any form, dosage or combination for at least one year was compared to another antioxidant vitamin or to placebo. Two authors extracted data and assessed trial quality independently. We pooled results for the primary outcomes, i.e., incidence of cataract and incidence of cataract extraction. We did not pool results of the secondary outcomes - progression of cataract and loss of visual acuity, because of differences in definitions of outcomes and data presentation. We pooled results by type of cataract when data were available. We did not perform a sensitivity analysis. Nine trials involving 117,272 individuals of age 35 years or older are included in this review. The trials were conducted in Australia, Finland, India, Italy, the United Kingdom and the United States, with duration of follow-up ranging from 2.1 to 12 years. The doses of antioxidant vitamins were higher than the recommended daily allowance. There was no evidence of effect of antioxidant vitamin supplementation in reducing the risk of cataract, cataract extraction, progression of cataract or in slowing the loss of visual acuity. In the pooled analyses, there was no evidence of effect of beta-carotene supplementation in reducing the risk of cataract (two trials) (relative risk (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.08; n = 57,703) or in reducing the risk of cataract extraction (three trials) (RR 1.00, 95% CI 0.91 to 1.10; n = 86,836) or of vitamin E supplementation in reducing the risk of cataract (three trials) (RR 0.97, 95% CI 0.91 to 1.04; n = 50,059) or of cataract extraction (five trials) (RR 0.98, 95% CI 0.91 to 1.05; n = 83,956). The proportion of participants developing hypercarotenodermia (yellowing of skin) while on beta-carotene ranged from 7.4% to 15.8%. There is no evidence from RCTs that supplementation with antioxidant vitamins (beta-carotene, vitamin C or vitamin E) prevents or slows the progression of age-related cataract. We do not recommend any further studies to examine the role of antioxidant vitamins beta-carotene, vitamin C and vitamin E in preventing or slowing the progression of age-related cataract. Costs and adverse effects should be weighed carefully with unproven benefits before recommending their intake above recommended daily allowances.

Nutraceuticals in prevention of cataract - An evidence based approach.

PubMed

Kaur, Amandeep; Gupta, Vikas; Christopher, Ajay Francis; Malik, Manzoor Ahmad; Bansal, Parveen

2017-01-01

Cataract is a principal cause of blindness in the world and is characterized by clouding of eye's natural lens. Surgery is the major therapeutic step taken to cure cataract; however, it is having its own limitations and complications such as iris prolapse, raised IOP, infection, cystoid macular edema and posterior capsular opacification (PCO). So world is looking toward more robust and natural ways to prevent cataract. One of the important factors that can play a role in prevention of any and many diseases is diet of the people. The inclusion of certain naturally occurring food and nutraceuticals is coming up as a best alternative for curing cataract because of their presumed safety, potential nutritional and therapeutic effects. Some nutraceuticals can act as an anticataract agent through some or the other molecular mechanism if consumed by normal population deliberately or inadvertently.

Evaluating visual function in cataract.

PubMed

Elliott, D B

1993-11-01

This paper reviews recent research on the evaluation of visual function in cataract. Visual impairment in cataract is principally caused by increased intraocular forward light scatter. It is assumed that visual acuity (VA) measurements assess the impact of narrow angle light scatter. This also makes the measurement of high spatial frequency contrast sensitivity (CS) unnecessary. However, VA measurements alone are an inadequate assessment of visual impairment in some patients with cataract. In addition, it is suggested that a measurement of wide-angle light scatter is required. This can be evaluated directly using the van den Berg Straylightmeter, or indirectly using low spatial frequency CS or disability glare (DG) tests. The following are discussed: (1) the relative usefulness of these tests; (2) how they can be incorporated into the decision as to when to extract a cataract; and (3) the importance of considering binocular visual function.

The concentration of light in the human lens.

PubMed Central

Merriam, J C

1996-01-01

PURPOSE: This thesis explores the idea that light energy, especially ultraviolet light, contributes to the unequal distribution of cataract around the world and to the development of cortical opacities. METHODS: In the first section, the thesis reviews historical concepts of the function of the lens and the nature of cataract, epidemiologic data on the global distribution of cataract, and clinical observations of the predominant location of cortical opacification. Second, computer ray tracings and geometric optics demonstrate the passage of light of varying angle of incidence within the lens. Third, two models of the human eye are used to study the refraction of light by the cornea and lens and illustrate the concentration of energy at the equatorial plane of the lens. RESULTS: Cataract prevalence increases with proximity to the earth's equator, and cortical cataract is most common in the inferior and inferonasal lens. Theoretical studies and the eye models both demonstrate that the concentration of light within the lens increases with angle of incidence, and the eye models suggest that the inferior and inferonasal lens receives significantly more energy than other sections of the lens. CONCLUSION: The prevalence of cataract and exposure to ultraviolet energy both increase with decreasing latitude. The most common location of cortical cataract in the inferonasal lens is consistent with the greater dose of light energy received by this portion of the lens. These studies suggest that the global distribution of cataract and the development of cortical cataract are at least in part dependent on the dose of ultraviolet light received by the lens. Images FIGURE 1 FIGURE 2 FIGURE 27 FIGURE 28 FIGURE 29 FIGURE 31 FIGURE 32 FIGURE 33 FIGURE 34 FIGURE 36 FIGURE 37 FIGURE 38 FIGURE 50 FIGURE 51 FIGURE 52 FIGURE 53 FIGURE 54 FIGURE 56 FIGURE 60 FIGURE 61 FIGURE 63 FIGURE 64 FIGURE 65 FIGURE 68 FIGURE 69 FIGURE 70 FIGURE 71 PMID:8981716

Prevalence of visual impairment and outcomes of cataract surgery in Chaonan, South China

PubMed Central

Zhang, Xiujuan; Li, Emmy Y.; Leung, Christopher Kai-Shun; Musch, David C.; Tang, Xin; Zheng, Chongren; He, Mingguang; Chang, David F.

2017-01-01

Purpose To estimate the prevalence and causes of blindness and visual impairment (VI), and report the outcomes of cataract surgery in Chaonan Region, Guangdong Province, southern China Design Cross-sectional population-based survey Participants A total of 3484 participants including 1397 men (40.1%) and 2087 women (59.9%) aged ≥50 years were examined (94.2% response rate). Method A two-stage cluster sampling procedure was used to select 3700 participants aged ≥50 years from 74 clusters of Chaonan Region. Participants were examined according to the Rapid Assessment of Avoidable Blindness (RAAB) method. Blindness and visual impairment (VI) were defined by the World Health Organization criteria. Participants with visual acuity (VA) < 6/18 in either eye were examined by ophthalmologists. The primary causes of blindness and VI were reported with reference to the participant’s better eye. Main outcome measures Prevalence and main causes of blindness, severe visual impairment (SVI), VI and the outcomes of cataract surgery Results The standardized prevalence rates of blindness, SVI, and VI were 2.4% (95% confidence interval [CI], 1.9–2.9%), 1.0% (95% CI, 0.7–1.4%), and 6.4% (95% CI, 5.6%– 7.1%), respectively. The principal cause of blindness and SVI was cataract, accounting for 67.1% and 67.6% respectively, and the principal cause of VI was refractive error (46.9%). One hundred and fifty five out of 3484 (4.4%) people (211 eyes) had cataract surgery. Of the 211 eyes that had cataract surgery, 96.7% were pseudophakic. 67.2% of the 211 operated eyes had a presenting visual acuity (PVA) of 6/18 or better. Conclusions The prevalence of blindness, SVI, and VI was high among rural residents in Chaonan. Cataract remained the leading cause of avoidable blindness. Outcomes of cataract surgery performed in rural private clinics were suboptimal. Quality-control initiatives such as hands-on training program should be introduced to improve cataract surgery outcomes. PMID:28797099

Reducing Older Driver Motor Vehicle Collisions via Earlier Cataract Surgery

PubMed Central

Mennemeyer, Stephen T.; Owsley, Cynthia; McGwin, Gerald

2013-01-01

Older adults who undergo cataract extraction have roughly half the rate of motor vehicle collision (MVC) involvement per mile driven compared to cataract patients who do not elect cataract surgery. Currently in the U.S., most insurers do not allow payment for cataract surgery based upon the findings of a vision exam unless accompanied by an individual’s complaint of visual difficulties that seriously interfere with driving or other daily activities and individuals themselves may be slow or reluctant to complain and seek relief. As a consequence, surgery tends to occur after significant vision problems have emerged. We hypothesize that a proactive policy encouraging cataract surgery earlier for a lesser level of complaint would significantly reduce MVCs among older drivers. We used a Monte Carlo model to simulate the MVC experience of the U.S. population from age 60 to 89 under alternative protocols for the timing of cataract surgery which we call “Current Practice” (CP) and “Earlier Surgery” (ES). Our base model finds, from a societal perspective with undiscounted 2010 dollars, that switching to ES from CP reduces by about 21% the average number of MVCs, fatalities, and MVC cost per person. The net effect on total cost – all MVC costs plus cataract surgery expenditures -- is a reduction of about 16%. Quality Adjusted Life Years would increase by about 5%. From the perspective of payers for healthcare, the switch would increase cataract surgery expenditure for ages 65+ by about 8% and for ages 60 to 64 by about 47% but these expenditures are substantially offset after age 65 by reductions in the medical and emergency services component of MVC cost. Similar results occur with discounting at 3% and with various sensitivity analyses. We conclude that a policy of ES would significantly reduce MVCs and their associated consequences. PMID:23369786

Prevalence of blindness and cataract surgery in Gandaki Zone, Nepal

PubMed Central

Sapkota, Y D; Pokharel, G P; Nirmalan, P K; Dulal, S; Maharjan, I M; Prakash, K

2006-01-01

Background/aim Himalaya Eye Hospital (HEH), established in 1993, is rendering eye care services in the Gandaki and Dhaulagiri zones. The hospital has extensive community outreach activities along with services for outpatients, emergencies, and subspecialties such as vitreoretinal, paediatric, and low vision. The operation theatre is well equipped to match the surgical needs including phaco surgery for cataract. The hospital has performed more than 14 000 cataract surgeries and 250 000 treatment services during this period. The aim of this study was to estimate the prevalence of blindness, visual impairment, and cataract surgical coverage among the older adult population of three districts of Gandaki Zone, where 80% of the hospital's service recipients reside. Methods People aged 45 years and older were enrolled in the study using a stratified cluster design. Subjects in 25 randomly selected clusters from the listed 806 were recruited through door to door visits. Each recruited subject had visual acuity (VA) and clinical examination conducted by an ophthalmologist. The survey was preceded by pre‐pilot and pilot studies to refine the operational method. To assess quality assurance the interobserver variation in VA measurement was also carried out in five different clusters. Results Out of 5863 selected subjects 85.3% were examined. Blindness defined as presenting VA <6/60 in both eyes was found in 2.6% (95% confidence interval (CI): 2.2 to 3.9), whereas 16.8% individuals examined had vision <6/19 in one or both eyes. Cataract was the principal cause of blindness in 60.5%, and refractive error was the dominant cause of vision impairment (<6/19) 83.3%. Cataract surgical coverage was 59.5% among the cataract blind and associated with younger age, literacy, and male sex. Conclusion The finding suggests a positive impact of the HEH programme on the prevalence of blindness and cataract surgical services in the survey area. Strategies to further improve access and utilisation of facilities and increase cataract surgical coverage need to be developed. PMID:16547315

Patient considerations in cataract surgery - the role of combined therapy using phenylephrine and ketorolac.

PubMed

Gonzalez-Salinas, Roberto; Guarnieri, Adriano; Guirao Navarro, María Concepción; Saenz-de-Viteri, Manuel

2016-01-01

Cataract, a degradation of the optical quality of the crystalline lens, progressive and age-related, is the leading cause of treatable blindness worldwide. Cataract surgery is the most common surgical procedure performed by ophthalmologists and is the only effective treatment for cataracts. Advances in the surgical techniques and better postoperative visual outcomes have progressively changed the primary concern of cataract surgery to become a procedure refined to yield the best possible refractive results. Sufficient mydriasis during cataract removal is critical to a successful surgical outcome. Poor pupil dilation can lead to serious sight-threatening complications that significantly increase the cost of surgery and decrease patients comfort. Mydriasis is obtained using anticholinergic and sympathomimetic drugs. Phenylephrine, an α1-adrenergic receptor agonist, can efficiently dilate the pupil when administered by intracameral injection. Additionally, nonsteroidal anti-inflammatory drugs (NSAIDs) like ketorolac, which inhibit the synthesis of prostaglandins, are used to decrease intraoperative miosis, control pain and inflammation associated with cataract surgery, and to prevent the development of cystoid macular edema following surgery. Recently, a new combination of phenylephrine and ketorolac (Omidria ® ) has been approved by United States Food and Drug Administration for use during cataract surgery to maintain intraoperative mydriasis, prevent miosis, and reduce postoperative pain and inflammation. Clinical trials have shown that this new combination is effective, combining the positive effects of both drugs with a good safety profile and patient tolerability. Moreover, recent reports suggest that this combination is also effective in patients with high risk of poor pupil dilation. In conclusion, cataract is a global problem that significantly affects patients' quality of life. However, they can be managed with a safe and minimally invasive surgery. Advances in surgical techniques and newer pharmacological agents such as the combination of phenylephrine and ketorolac, together with better intraocular lenses, have greatly improved visual outcomes and thus patients' expectations regarding visual recovery are also increasing.

Congenital cataracts and other abnormalities in a female with 46.X, del(X)(q26q28)mat: A new locus for X-linked congenital cataract?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babul, R.; Chitayat, D.; Teshima, I.

1994-09-01

Three forms of X-linked congenital cataracts have been delineated: congenital cataract with posterior Y-sutural opacities in heterozygotes, congenital cataract and microcornea or microphthalmia and congenital cataract-dental syndrome (Nance-Horan syndrome). Of these, only the Nance-Horan syndrome has been mapped to Xp22.3-p21.1. However, Warburg has suggested that these different forms of X-linked congenital cataracts are due to deletions of varying sizes, placing them in the vicinity of the Nance-Horan syndrome region. We report on a female patient born to a 29-year-old primigravida woman who at birth was found to have hypotonia, dysmorphic facial features, hydrocephalus and dense white congenital bilateral cataracts. Othermore » ophthalmological findings included bilateral nystagmus and shallow orbits. Chromosome analysis revealed 46,X,del(X)(q26q28)mat. The mother, however, is phenotypically normal. Brain CT scan on the female infant revealed communicating hydrocephalus and a muscle biopsy showed congenital muscle fiber disproportion. An EMG and NCV were normal. At 4 years of age, her height and weight were below -3SD and her OFC was +2SD. Molecular studies using DNA markers located in Xq26-qter have revealed that the proximal breakpoint in the patient and her mother is defined by the HPRT locus while the distal breakpoint is defined by the locus DXS1108. This indicates that the deletion is not terminal but rather interstitial, retaining sequences proximal to the telomeric region. Other molecular studies are in progress to determine the X-inactivation status of the deleted chromosome in our patient and her mother as a possible explanation for the variation in the phenotype. These clinical and molecular findings suggest that another locus for X-linked congenital cataract exists at Xq26-28.« less

Willingness to pay for cataract surgery is much lower than actual costs in Zamfara state, northern Nigeria.

PubMed

Ibrahim, Nazaradden; Ramke, Jacqueline; Pozo-Martin, Francisco; Gilbert, Clare E

2018-06-01

Direct medical and non-medical costs incurred by those undergoing subsidised cataract surgery at Gusau eye clinic, Zamfara state, were recently determined. The aim of this study was to assess the willingness to pay for cataract surgery among adults with severe visual impairment or blindness from cataract in rural Zamfara and to compare this to actual costs. In three rural villages served by Gusau eye clinic, key informants helped identify 80 adults with bilateral severe visual impairment or blindness (<6/60), with cataract being the cause in at least one eye. The median amount participants were willing to pay for cataract surgery was determined. The proportion willing to pay actual costs of the (i) subsidised surgical fee (US$18.5), (ii) average non-medical expenses (US$25.2), and (iii) average total expenses (US$51.2) at Gusau eye clinic were calculated. Where participants would seek funds for surgery was determined. Among 80 participants (38% women), most (n = 73, 91%) were willing to pay something, ranging from

Cataract, ocular surgery, aphakia, and the chromatic expression of the painter Jovan Bijelić.

PubMed

Nikolić, Ljubiša; Jovanović, Vesna

2016-11-01

Approaching art from the standpoint of optics and the artist’s eye pathology can sometimes explain the shift of the spectral colors in the work of some artists with cataract and aphakia. This may not be obvious in the paintings of other artists with the same eye pathology. The aim of this study was to create a timeline from the recently obtained details of the cataract surgery, his best corrected aphakic visual acuity, and the last paintings of the artist Jovan Bijelić. The research included primary and secondary source material: Bijelić’s paintings from all stages of his career, interviews with Bijelić and his eye surgeon, art criticism, sources with the description of Bijelić’s symptoms, hospital archives, discussion with art historians, comparison of his palette from different periods. Jovan Bijelić was nearly blind from cataract in 1957. He underwent an unsuccessful cataract surgery in 1956, followed by enucleation of the operated eye. In 1958, 20/25–20/20 vision was regained, after the extracapsular cataract extraction and sector iridectomy in his right eye, with the posterior lens capsule discision afterwards. Xanthopsia and cyanopsia are not present in his art, which is not a representation of visualized objects. The response of Jovan Bijelić to cataract and aphakia was predominantly a change of his style.

Microscope Integrated Intraoperative Spectral Domain Optical Coherence Tomography for Cataract Surgery: Uses and Applications.

PubMed

Das, Sudeep; Kummelil, Mathew Kurian; Kharbanda, Varun; Arora, Vishal; Nagappa, Somshekar; Shetty, Rohit; Shetty, Bhujang K

2016-05-01

To demonstrate the uses and applications of a microscope integrated intraoperative Optical Coherence Tomography in Micro Incision Cataract Surgery (MICS) and Femtosecond Laser Assisted Cataract Surgery (FLACS). Intraoperative real time imaging using the RESCAN™ 700 (Carl Zeiss Meditec, Oberkochen, Germany) was done for patients undergoing MICS as well as FLACS. The OCT videos were reviewed at each step of the procedure and the findings were noted and analyzed. Microscope Integrated Intraoperative Optical Coherence Tomography was found to be beneficial during all the critical steps of cataract surgery. We were able to qualitatively assess wound morphology in clear corneal incisions, in terms of subclinical Descemet's detachments, tears in the inner or outer wound lips, wound gaping at the end of surgery and in identifying the adequacy of stromal hydration, for both FLACS as well as MICS. It also enabled us to segregate true posterior polar cataracts from suspected cases intraoperatively. Deciding the adequate depth of trenching was made simpler with direct visualization. The final position of the intraocular lens in the capsular bag and the lack of bioadhesivity of hydrophobic acrylic lenses were also observed. Even though Microscope Integrated Intraoperative Optical Coherence Tomography is in its early stages for its application in cataract surgery, this initial assessment does show a very promising role for this technology in the future for cataract surgery both in intraoperative decision making as well as for training purposes.

Eye healthcare services in eastern Europe: Part 1 Cataract surgery

PubMed Central

Kocur, I; Resnikoff, S; Foster, A

2002-01-01

Aim: To describe cataract surgical services in 1998 in 12 eastern European countries and to identify their needs to reduce cataract blindness. Methods: All inpatient eye departments in the 12 countries received a standardised questionnaire; the data obtained were further processed at the coordinating centre in Prague. Results: All 458 eye departments in the region were involved. The response rate was 100%, except for Bulgaria (93%) and Romania (93%). The total number of cataract surgeries per one million inhabitants in 1998 was calculated: Belarus (800), Federation of Bosnia and Herzegovina (1275), Bulgaria (1730), the Czech Republic (4210), Estonia (2530), Hungary (3530), Latvia (1860), Lithuania (1550), Trans-Dniester Moldova (1300), Poland (1475), Romania (1260), and Slovakia (2430). Cataracts were mostly operated on by the extracapsular technique. Intracapsular extractions were frequently performed in Federation of Bosnia and Herzegovina (47%), Belarus (46%), Bulgaria (18%), and Romania (14.3%). Phacoemulsification was uncommonly used in 1998, except for the Czech Republic (86%), Estonia (50%), Slovakia (38%), and Hungary (16%). An IOL was implanted in more than 90% of patients in the Czech Republic, Estonia, Hungary, Latvia, Lithuania, and Slovakia. Conclusions: Conditions for cataract surgery in the eastern European region differ. The main barriers to cataract surgery were state budget limitations, insufficient supply of consumables, underutilisation of operating theatres, and poor detection of patients requiring surgery. PMID:12140200

Gestational diabetes and the long-term risk of cataract surgery: A longitudinal cohort study.

PubMed

Auger, Nathalie; Tang, Tina; Healy-Profitós, Jessica; Paradis, Gilles

2017-11-01

We assessed the long-term risk of cataract following a pregnancy complicated by gestational diabetes. We carried out a longitudinal cohort study of 1,108,541 women who delivered infants between 1989-2013 in Quebec, Canada, with follow-up extending up to 25years later. The cohort included 71,862 women with gestational diabetes and 5247 with cataracts. We used Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association of gestational diabetes with subsequent risk of cataract, adjusted for age, parity, socioeconomic status, time period, comorbidity, and type 2 diabetes. Women with gestational diabetes had an elevated incidence of cataract (22.6 per 1000) compared with no gestational diabetes (15.1 per 1000), with 1.15 times the risk (95% CI 1.04-1.28). Women with gestational diabetes who subsequently developed type 2 diabetes had a higher risk of cataract compared with no gestational and type 2 diabetes (HR 3.62, 95% CI 3.01-4.35), but women with gestational diabetes who did not develop type 2 diabetes continued to be at risk (HR 1.12, 95% CI 1.00-1.25). Gestational diabetes may be an independent risk factor for cataract later in life, although risks are greatest for women who subsequently develop type 2 diabetes. Copyright © 2017 Elsevier Inc. All rights reserved.

Changes in Intraocular Straylight and Visual Acuity with Age in Cataracts of Different Morphologies

PubMed Central

Reus, Nicolaas J.; van den Berg, Thomas J. T. P.

2017-01-01

Purpose To investigate the significance of difference in straylight of cataract eyes with different morphologies, as a function of age and visual acuity. Methods A literature review to collect relevant papers on straylight, age, and visual acuity of three common cataract morphologies leads to including five eligible papers for the analysis. The effect of morphology was incorporated to categorize straylight dependency on the two variables. We also determined the amount of progression in a cataract group using a control group. Results The mean straylight was 1.22 log units ± 0.20 (SD) in nuclear (592 eyes), 1.26 log units ± 0.23 in cortical (776 eyes), and 1.48 log units ± 0.34 in posterior subcapsular (75 eyes) groups. The slope of straylight-age relationship was 0.009 (R 2 = 0.20) in nuclear, 0.012 (R 2 = 0.22) in cortical, and 0.014 (R 2 = 0.11) in posterior subcapsular groups. The slope of straylight-visual acuity relationship was 0.62 (R 2 = 0.25) in nuclear, 0.33 (R 2 = 0.13) in cortical, and 1.03 (R 2 = 0.34) in posterior subcapsular groups. Conclusion Considering morphology of cataract provides a better insight in assessing visual functions of cataract eyes, in posterior subcapsular cataract, particularly, in spite of notable elevated straylight, visual acuity might not manifest severe loss. PMID:28831307

Inhibition of aldose reductase from cataracted eye lenses by finger millet (Eleusine coracana) polyphenols.

PubMed

Chethan, S; Dharmesh, Shylaja M; Malleshi, Nagappa G

2008-12-01

Retinopathy is a major cause of blindness in the Western world, while cataract is one of the three major causes of blindness worldwide. Diabetes is one of the major risk factor in retinopathy and cataract. The prevalence of blindness in India is 15 per 1000 while cataract alone accounts for 80% of this blindness. Diabetes induced cataract is characterized by an accumulation of sorbitol which is mediated by the action of a key enzyme aldose reductase (AR). Non-enzymatic glycation (binding of glucose to protein molecule) induced during diabetes appear to be the key factor for AR mediated sugar-induced cataract. Finger millet polyphenols (FMP) being a major anti-diabetic and antioxidant component, we have evaluated them for AR inhibiting activity. Phenolic constituents in FMP such as gallic, protocatechuic, p-hydroxy benzoic, p-coumaric, vanillic, syringic, ferulic, trans-cinnamic acids and the quercetin inhibited cataract eye lens effectively, the latter was more potent with an IC(50) of 14.8nM. Structure function analysis revealed that phenolics with OH group at 4th position was important for aldose reductase inhibitory property. Also the presence of neighboring O-methyl group in phenolics denatured the AR activity. Finger millet seed coat polyphenols (SCP) has been found to inhibit AR reversibly by non-competitive inhibition. Results thus, provide a stronger evidence for the potentials of FMP in inhibiting cataractogenesis in humans.

Virtual Mentor Cataract Surgery Trainer

DTIC Science & Technology

2009-09-01

excessive lens movement), look for zonular absence, assess for notable lenticular astigmatism ** How and when do you decide to use a capsular...AD_________________ AWARD NUMBER: W81XWH-08-1-0531 TITLE: Virtual Mentor Cataract Surgery Trainer...REPORT TYPE Annual 3. DATES COVERED 20 Aug 2008 – 19 Aug 2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Virtual Mentor Cataract Surgery

Femtosecond laser-assisted cataract surgery in anterior lenticonus due to Alport syndrome.

PubMed

Barnes, Alexander C; Roth, Allen S

2017-06-01

We describe a case of bilateral anterior lenticonus in a patient with Alport syndrome treated with femtosecond laser-assisted cataract surgery (FLACS). FLACS was performed without complication, and a desirable postoperative visual acuity was achieved. Femtosecond laser-assisted cataract surgery is an effective approach for managing patients with anterior lenticonus secondary to Alport syndrome.

42 CFR 1001.1701 - Billing for services of assistant at surgery during cataract operations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 5 2013-10-01 2013-10-01 false Billing for services of assistant at surgery during... PROGRAMS Permissive Exclusions § 1001.1701 Billing for services of assistant at surgery during cataract... surgery during a cataract operation, or (ii) Charges that include a charge for an assistant at surgery...

42 CFR 1001.1701 - Billing for services of assistant at surgery during cataract operations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Billing for services of assistant at surgery during... PROGRAMS Permissive Exclusions § 1001.1701 Billing for services of assistant at surgery during cataract... surgery during a cataract operation, or (ii) Charges that include a charge for an assistant at surgery...

42 CFR 1001.1701 - Billing for services of assistant at surgery during cataract operations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 5 2012-10-01 2012-10-01 false Billing for services of assistant at surgery during... PROGRAMS Permissive Exclusions § 1001.1701 Billing for services of assistant at surgery during cataract... surgery during a cataract operation, or (ii) Charges that include a charge for an assistant at surgery...

42 CFR 1001.1701 - Billing for services of assistant at surgery during cataract operations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 5 2014-10-01 2014-10-01 false Billing for services of assistant at surgery during... PROGRAMS Permissive Exclusions § 1001.1701 Billing for services of assistant at surgery during cataract... surgery during a cataract operation, or (ii) Charges that include a charge for an assistant at surgery...

42 CFR 1001.1701 - Billing for services of assistant at surgery during cataract operations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 5 2011-10-01 2011-10-01 false Billing for services of assistant at surgery during... PROGRAMS Permissive Exclusions § 1001.1701 Billing for services of assistant at surgery during cataract... surgery during a cataract operation, or (ii) Charges that include a charge for an assistant at surgery...

Association of Social Support Network Size With Receipt of Cataract Surgery in Older Adults.

PubMed

Stagg, Brian C; Choi, HwaJung; Woodward, Maria A; Ehrlich, Joshua R

2018-04-01

Cataract-related vision impairment is an important public health issue that tends to affect older adults. Little is known about the association between older adults' social support networks and their likelihood of receiving cataract surgery. To determine if older adults with smaller social support networks are less likely to receive cataract surgery. Retrospective cohort study. The National Health and Aging Trends Study, a nationally representative US survey, administered annually from 2011 to 2015 to a cohort of Medicare beneficiaries 65 years and older with no cataract surgery prior to the start of the study. Multivariable logistic regression was performed to evaluate if the number of persons in an individual's social support network influenced whether that individual received cataract surgery during a given year of the study. Overall, 3448 participants were interviewed from 2011 to 2015 for a total of 9760 observations. Of these observations, 3084 (weighted, 38.81%; 95% CI, 37.28-40.35) were aged 70 to 74 years, 5211 (weighted, 52.32%; 95% CI, 50.19-54.44) were women; 5899 (weighted, 78.53%; 95% CI, 76.29-80.61) were white, 2249 (weighted, 9.55%; 95% CI, 8.45-10.78) were black, 537 (weighted, 7.18%; 95% CI, 5.88-8.73) were Hispanic, and 303 (weighted, 4.74%; 95% CI, 3.56-62.9) reported other races. Medicare beneficiaries with smaller social support networks (0-2 individuals) were less likely to receive cataract surgery in a given year (adjusted odds ratio, 0.60; 95% CI, 0.37-0.96) than those with larger support networks (≥3 individuals). The adjusted predicted proportion of Medicare beneficiaries undergoing cataract surgery was 4.7% (95% CI, 2.7%-6.7%) and 7.5% (95% CI, 6.9%-8.1%) for those with small and large social support networks, respectively. Having fewer non-spouse/partner family members in the support network was associated with decreased odds of receiving cataract surgery (adjusted odds ratio, 0.60; 95% CI, 0.43-0.85), but having spouses/partners (adjusted odds ratio, 0.97; 95% CI, 0.77-1.22) and nonfamily members (adjusted odds ratio, 0.90; 95% CI, 0.72-1.11) did not have a significant association. Medicare beneficiaries with fewer non-spouse/partner family members in their social support networks were less likely to receive cataract surgery. These findings suggest that attention should be given to patients with smaller support networks to ensure that they receive cataract surgery when it is indicated.

CHANGES IN FERRITIN H- AND L-CHAINS IN CANINE LENSES WITH AGE-RELATED NUCLEAR CATARACT

PubMed Central

Goralska, Małgorzata; Nagar, Steven; Colitz, Carmen M.H.; Fleisher, Lloyd N.; McGahan, M. Christine

2014-01-01

PURPOSE To determine potential differences in the characteristics of the iron storage protein, ferritin and its heavy (H) and light (L) subunits in fiber cells from cataractous and normal lenses of older dogs. METHODS Lens fiber cell homogenates were analyzed by SDS-PAGE and ferritin chains were immunodetected with ferritin chain-specific antibodies. Ferritin concentration was measured by ELISA. Immunohistochemistry was used to localize ferritin chains in lens sections. RESULTS The concentration of assembled ferritin was comparable in normal and cataractous lenses of similarly aged dogs. The ferritin L-chain detected in both lens types was modified and was about 11 kDa larger (30 kDa) than standard L-chain (19 kDa) purified from canine liver. The H-chain identified in cataractous fiber cells (29 kDa) differed from 21 kDa standard canine H-chain and from 12 kDa modified H-chain present in fiber cells of normal lenses. Histologic analysis revealed that the H-chain was distributed differently throughout cataractous lenses when compared to normal lenses. There was also a difference in subunit makeup of assembled ferritin between the two lens types. Ferritin from cataractous lenses contained more H-chain and bound 11-fold more iron than ferritin from normal lenses. CONCLUSIONS There are significant differences in the characteristics of ferritin H-chain and its distribution in canine cataractous lenses as compared to normal lenses. The higher content of H-chain in assembled ferritin allows this molecule to sequester more iron. In addition the accumulation of H-chain in deeper fiber layers of the lens may be part of a defense mechanism by which the cataractous lens limits iron-catalyzed oxidative damage. PMID:18708625

Relation between the axial length and lenticular progressive myopia.

PubMed

Lin, H-Y; Chang, C-W; Wang, H-Z; Tsai, R-K

2005-08-01

To investigate the possible risk factors associated with lenticular progressive myopia and to compare the differences between patients with lenticular progressive myopias and senile cataracts. We retrospectively reviewed cases that had been diagnosed as lenticular progressive myopia with a discrete nuclear sclerotic cataract and progressive myopic changes in one hospital from January 1998 to February 2003. A total of 47 eyes of 35 patients were enrolled in this study. In all, 32 eyes of 29 cases of common senile cataract receiving cataract extraction surgery during the study period were randomly chosen (every four cases in time sequence within a 2-month period by two ophthalmologists' clinic in 2002) as the control group. We compared the preoperative refraction status, keratometry (K-values) and axial lengths between these two groups. The possible ocular or systemic associating diseases were also investigated in the study group. In the lenticular progressive myopia group, the mean age at surgery (52.9+/-9.2 years) is younger than that in the senile cataract group (68.1+/-7.3 years). The mean axial length in the study group (25.68+/-1.93 mm) is statistically significant longer than that in the control group (22.97+/-0.83 mm) (P<0.0001). Besides, patients with lenticular progressive myopia had significantly lower mean K-values (43.25+/-1.42 diopters) than patients with senile cataracts (44.25+/-1.28 diopters) (P<0.01). There were no other ocular or systemic diseases closely associated with lenticular progressive myopia. Patients with nuclear cataract combined with lenticular progressive myopia have longer axial length than patients with senile cataract. The longer axial length may be one of the important risk factors predisposing to lenticular progressive myopia.

Initial experience using a femtosecond laser cataract surgery system at a UK National Health Service cataract surgery day care centre

PubMed Central

Dhallu, Sandeep K; Maurino, Vincenzo; Wilkins, Mark R

2016-01-01

Objectives To describe the initial outcomes following installation of a cataract surgery laser system. Setting National Health Service cataract surgery day care unit in North London, UK. Participants 158 eyes of 150 patients undergoing laser-assisted cataract surgery. Interventions Laser cataract surgery using the AMO Catalys femtosecond laser platform. Primary and secondary outcome measures Primary outcome measure: intraoperative complications including anterior and posterior capsule tears. Secondary outcome measures: docking to the laser platform, successful treatment delivery, postoperative visual acuities. Results Mean case age was 67.7±10.8 years (range 29–88 years). Docking was successful in 94% (148/158 cases), and in 4% (6/148 cases) of these, the laser delivery was aborted part way during delivery due to patient movement. A total of 32 surgeons, of grades from junior trainee to consultant, performed the surgeries. Median case number per surgeon was 3 (range from 1–20). The anterior capsulotomy was complete in 99.3% of cases, there were no anterior capsule tears (0%). There were 3 cases with posterior capsule rupture requiring anterior vitrectomy, and 1 with zonular dialysis requiring anterior vitrectomy (4/148 eyes, 2.7%). These 4 cases were performed by trainee surgeons, and were either their first laser cataract surgery (2 surgeons) or their first and second laser cataract surgeries (1 surgeon). Conclusions Despite the learning curve, docking and laser delivery were successfully performed in almost all cases, and surgical complication rates and visual outcomes were similar to those expected based on national data. Complications were predominately confined to trainee surgeons, and with the exception of intraoperative pupil constriction appeared unrelated to the laser-performed steps. PMID:27466243

Visual outcomes of bilateral congenital and developmental cataracts in young children in south India and causes of poor outcome

PubMed Central

Khanna, Rohit C; Foster, Allen; Krishnaiah, Sannapaneni; Mehta, Manohar K; Gogate, Parikshit M

2013-01-01

Context: Bilateral pediatric cataracts are important cause of visual impairment in children. Aim: To study the outcome of bilateral pediatric cataract surgery in young children. Setting and Design: Retrospective case series in a tertiary center. Materials and Methods: Records of pediatric cataracts operated between January 2001 and December 2003, with a minimum follow-up of 3 months, were reviewed retrospectively. Statistical Methods: Independent sample t-test, Fisher's exact test, and logistic regression using SPSS (Statistical Package for Social Science, Chicago, USA) version 12. Results: 215/257 (83.7%) patients had a minimum follow-up of 3 months. The mean age of presentation to the hospital was 53 months (range: 0-168 months). Congenital cataract was present in 107 patients (58.2%) and developmental cataract in 77 patients (41.8%). The mean age at surgery was 55.2 months (range: 1-168 months). Out of 430 eyes, 269 (62.6%) had an intraocular lens implanted. The mean duration of follow-up was 13.1 months (range: 3-38 months). Pre-operatively, 102 patients (47.3%) had visual acuity <6/60, in the better eye, compared to 37 patients (17.2%) post-operatively (P < 0.001). Eighty-five patients (39.5%) had visual acuity >6/18. The most common early post-operative complication was fibrinous uveitis in 57 eyes (13.3%) and the most common delayed post-operative complication was posterior capsular opacification in 118 eyes (27.4%). The most important prognostic factor for poor outcome was congenital cataract (odds ratio [OR]: 26.3; 95% confidence interval [CI], 4.4-158.5) and total cataract (OR: 4.8; 95% CI, 1.3-17). PMID:23412523

Visual outcome of cataract surgery; study from the European Registry of Quality Outcomes for Cataract and Refractive Surgery.

PubMed

Lundström, Mats; Barry, Peter; Henry, Ype; Rosen, Paul; Stenevi, Ulf

2013-05-01

To analyze the visual outcome after cataract surgery. Cataract surgery clinics in 15 European countries. Database study. Data were drawn from case series of cataract extractions reported to the European Registry of Quality Outcomes for Cataract and Refractive Surgery database. These data were entered into the database via the Web by surgeons or by transfer from existing national registries or electronic medical record systems. The database contains individual anonymous data on preoperative, intraoperative, and postoperative measurements. Data on 368,256 cataract extractions were available for analysis. The best visual outcome was achieved in age groups 40 to 74 years, and men showed a higher percentage of excellent vision (1.0 [20/20] or better) than women. A corrected distance visual acuity (CDVA) of 0.5 (20/40) or better and of 1.0 (20/20) or better was achieved in 94.3% and 61.3% of cases, respectively. Ocular comorbidity and postoperative complications were the strongest influences on the visual outcome; however, surgical complications and ocular changes requiring complex surgery also had a negative influence. Deterioration of visual acuity after the surgery (n= 6112 [1.7% of all cases]) was most common in patients with a good preoperative visual acuity. The visual outcomes of cataract surgery were excellent, with 61.3% of patients achieving a corrected distance visual acuity of 1.0 (20/20) or better. Age and sex influenced the visual outcomes, but the greatest influences were short-term postoperative complications, ocular comorbidity, surgical complications, and complex surgery. A weakness of the study could be that some of the data is self-reported to the registry. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

NIKE: a new clinical tool for establishing levels of indications for cataract surgery.

PubMed

Lundström, Mats; Albrecht, Susanne; Håkansson, Ingemar; Lorefors, Ragnhild; Ohlsson, Sven; Polland, Werner; Schmid, Andrea; Svensson, Göran; Wendel, Eva

2006-08-01

The purpose of this study was to construct a new clinical tool for establishing levels of indications for cataract surgery, and to validate this tool. Teams from nine eye clinics reached an agreement about the need to develop a clinical tool for setting levels of indications for cataract surgery and about the items that should be included in the tool. The tool was to be called 'NIKE' (Nationell Indikationsmodell för Kataraktextraktion). The Canadian Cataract Priority Criteria Tool served as a model for the NIKE tool, which was modified for Swedish conditions. Items included in the tool were visual acuity of both eyes, patients' perceived difficulties in day-to-day life, cataract symptoms, the ability to live independently, and medical/ophthalmic reasons for surgery. The tool was validated and tested in 343 cataract surgery patients. Validity, stability and reliability were tested and the outcome of surgery was studied in relation to the indication setting. Four indication groups (IGs) were suggested. The group with the greatest indications for surgery was named group 1 and that with the lowest, group 4. Validity was proved to be good. Surgery had the greatest impact on the group with the highest indications for surgery. Test-retest reliability test and interexaminer tests of indication settings showed statistically significant intraclass correlations (intraclass correlation coefficients [ICCs] 0.526 and 0.923, respectively). A new clinical tool for indication setting in cataract surgery is presented. This tool, the NIKE, takes into account both visual acuity and the patient's perceived problems in day-to-day life because of cataract. The tool seems to be stable and reliable and neutral towards different examiners.

Ultrasonographic Findings in Patients Examined in Cataract Detection-and-Treatment Campaigns: A Retrospective Study

PubMed Central

Mendes, Marcio Henrique; Betinjane, Alberto Jorge; de Sá Cavalcante, Adhele; Te Cheng, Cheng; Kara-José, Newton

2009-01-01

INTRODUCTION: A cataract is defined as an opacity of any portion of the lens, regardless of visual acuity. In some advanced cases of cataracts, in which good fundus visualization is not possible, an ultrasound examination provides better assessment of the posterior segment of the globe. OBJECTIVES: This study aims to evaluate the ultrasonographic records of patients with advanced cataracts who were examined during cataract campaigns. METHODS: The ultrasonographic findings obtained from 215 patients examined in cataract campaigns conducted by the Hospital das Clínicas Department of Ophthalmology of the Faculdade de Medicina da Universidade de São Paulo between the years of 2005 and 2007 were evaluated, and the utility of this exam in changing the treatment procedures was studied. RESULTS: A total of 289 eyes from 215 patients were examined. Of the eyes examined, 77.5% presented with findings in the vitreous cavity and the posterior pole. A posterior vitreous detachment with no other complications was observed in 47.4% of the eyes. The remaining 30.1% presented with eye diseases that could result in a reduced visual function after surgery. The most frequent eye diseases observed were diffuse vitreous opacity (12.1% of the eyes) and detachment of the retina (9.3% of the eyes). DISCUSSION: In many cases, the ultrasonographic evaluation of the posterior segment revealed significant anomalies that changed the original treatment plan or contra-indicated surgery. At the very least, the evaluation was useful for patient counseling. CONCLUSION: The ultrasonographic examination revealed and differentiated between eyes with cataracts and eyes with ocular abnormalities other than cataracts as the cause of poor vision, thereby indicating the importance of its use during ocular evaluation. PMID:19606238

Epidemiology and intermediate-term outcomes of open- and closed-globe injuries in traumatic childhood cataract.

PubMed

Khokhar, Sudarshan; Gupta, Shikha; Yogi, Rohit; Gogia, Varun; Agarwal, Tushar

2014-01-01

To study epidemiology and intermediate-term outcomes of open- and closed-globe injuries (CGI) in traumatic childhood cataract. In this retrospective interventional case series, demographic parameters and history including type of injury of 57 children younger than 16 years with traumatic cataract were recorded; ocular examination included best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, and posterior segment evaluation. Patients underwent cataract surgery with or without intraocular lens (IOL) implantation. Main surgical outcomes at 6 months comprised BCVA, residual refractive spherical error (SE), and postoperative complications, namely visual axis opacification (VAO) and amblyopia. Bow and arrow was the most common causal agent. Open-globe injury (OGI) was 3 times more frequent than CGI. There was a significant visual gain from baseline in both groups after cataract surgery (p<0.001); residual SE was greater in OGI (1.6 ± 0.95 SD) compared to blunt trauma (0.8 ± 0.55 SD; p = 0.001). Incidence of corneal scarring, iris distortion, posterior synechiae, and intraoperative posterior capsular tear was greater with OGI (p<0.05). A total of 86% of patients were rehabilitated with a primary/secondary IOL. Single-piece IOL implantation rate (p = 0.004) was significantly greater in CGI, with no statistical difference for in-the-bag IOL (p = 0.053) and IOL implantation rate (p = 0.16). Final BCVA was significantly better for in-the-bag IOL implantation compared to sulcus fixation. Postoperative complications included amblyopia (51%) and VAO (12%). Bow and arrow injury caused the maximum cases of traumatic cataract; cataract extraction resulted in significant visual improvement; and CGI tended to have better prognosis in pediatric traumatic cataracts.

Autosomal Dominant Cataract: Intrafamilial Phenotypic Variability, Interocular Asymmetry, and Variable Progression in Four Chilean Families

PubMed Central

Shafie, Suraiya M.; Barria von-Bischhoffshausen, Fernando R.; Bateman, J. Bronwyn

2006-01-01

PURPOSE To document intrafamilial and interocular phenotypic variability of autosomal dominant cataract (ADC). DESIGN Prospective observational case series. METHODS We performed ophthalmologic examination in four Chilean ADC families. RESULTS The families exhibited variability with respect to morphology, location with the lens, color and density of cataracts among affected members. We documented asymmetry between eyes in the morphology, location within the lens, color and density of cataracts, and a variable rate of progression. CONCLUSIONS The cataracts in these families exhibit wide intrafamilial and interocular phenotypic variability, supporting the premise that the mutated genes are expressed differentially in individuals and between eyes; other genes or environmental factors may be the bases for this variability. Marked progression among some family members underscores the variable clinical course of a common mutation within a family. Like retinitis pigmentosa, classification of ADC will be most useful if based on the gene and specific mutation. PMID:16564818

Space radiation and cataracts in astronauts.

PubMed

Cucinotta, F A; Manuel, F K; Jones, J; Iszard, G; Murrey, J; Djojonegro, B; Wear, M

2001-11-01

For over 30 years, astronauts in Earth orbit or on missions to the moon have been exposed to space radiation comprised of high-energy protons and heavy ions and secondary particles produced in collisions with spacecraft and tissue. Large uncertainties exist in the projection of risks of late effects from space radiation such as cancer and cataracts due to the paucity [corrected] of epidemiological data. Here we present epidemiological [corrected] data linking an increased risk of cataracts for astronauts with higher lens doses (>8 mSv) of space radiation relative to other astronauts with lower lens doses (<8 mSv). Our study uses historical data for cataract incidence in the 295 astronauts participating in NASA's Longitudinal Study of Astronaut Health (LSAH) and individual occupational radiation exposure data. These results, while preliminary because of the use of subjective scoring methods, suggest that relatively low doses of space radiation may predispose crew to [corrected] an increased incidence and early appearance of cataracts.

Space radiation and cataracts in astronauts

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Manuel, F. K.; Jones, J.; Iszard, G.; Murrey, J.; Djojonegro, B.; Wear, M.

2001-01-01

For over 30 years, astronauts in Earth orbit or on missions to the moon have been exposed to space radiation comprised of high-energy protons and heavy ions and secondary particles produced in collisions with spacecraft and tissue. Large uncertainties exist in the projection of risks of late effects from space radiation such as cancer and cataracts due to the paucity [corrected] of epidemiological data. Here we present epidemiological [corrected] data linking an increased risk of cataracts for astronauts with higher lens doses (>8 mSv) of space radiation relative to other astronauts with lower lens doses (<8 mSv). Our study uses historical data for cataract incidence in the 295 astronauts participating in NASA's Longitudinal Study of Astronaut Health (LSAH) and individual occupational radiation exposure data. These results, while preliminary because of the use of subjective scoring methods, suggest that relatively low doses of space radiation may predispose crew to [corrected] an increased incidence and early appearance of cataracts.

Expert System Diagnosis of Cataract Eyes Using Fuzzy Mamdani Method

NASA Astrophysics Data System (ADS)

Santosa, I.; Romla, L.; Herawati, S.

2018-01-01

Cataracts are eye diseases characterized by cloudy or opacity of the lens of the eye by changing the colour of black into grey-white which slowly continues to grow and develop without feeling pain and pain that can cause blindness in human vision. Therefore, researchers make an expert system of cataract eye disease diagnosis by using Fuzzy Mamdani and how to care. The fuzzy method can convert the crisp value to linguistic value by fuzzification and includes in the rule. So this system produces an application program that can help the public in knowing cataract eye disease and how to care based on the symptoms suffered. From the results of the design implementation and testing of expert system applications to diagnose eye disease cataracts, it can be concluded that from a trial of 50 cases of data, obtained test results accuracy between system predictions with expert predictions obtained a value of 78% truth.

A Preoperative Medical History and Physical Should Not Be a Requirement for All Cataract Patients.

PubMed

Schein, Oliver D; Pronovost, Peter J

2017-07-01

Cataract surgery poses minimal systemic medical risk, yet a preoperative general medical history and physical is required by the Centers for Medicare and Medicaid Services and other regulatory bodies within 1 month of cataract surgery. Based on prior research and practice guidelines, there is professional consensus that preoperative laboratory testing confers no benefit when routinely performed on cataract surgical patients. Such testing remains commonplace. Although not yet tested in a large-scale trial, there is also no evidence that the required history and physical yields a benefit for most cataract surgical patients above and beyond the screening performed by anesthesia staff on the day of surgery. We propose that the minority of patients who might benefit from a preoperative medical history and physical can be identified prospectively. Regulatory agencies should not constrain medical practice in a way that adds enormous cost and patient burden in the absence of value.

Postoperative Refractive Errors Following Pediatric Cataract Extraction with Intraocular Lens Implantation.

PubMed

Indaram, Maanasa; VanderVeen, Deborah K

2018-01-01

Advances in surgical techniques allow implantation of intraocular lenses (IOL) with cataract extraction, even in young children. However, there are several challenges unique to the pediatric population that result in greater degrees of postoperative refractive error compared to adults. Literature review of the techniques and outcomes of pediatric cataract surgery with IOL implantation. Pediatric cataract surgery is associated with several sources of postoperative refractive error. These include planned refractive error based on age or fellow eye status, loss of accommodation, and unexpected refractive errors due to inaccuracies in biometry technique, use of IOL power formulas based on adult normative values, and late refractive changes due to unpredictable eye growth. Several factors can preclude the achievement of optimal refractive status following pediatric cataract extraction with IOL implantation. There is a need for new technology to reduce postoperative refractive surprises and address refractive adjustment in a growing eye.

Human cataract: the mechanisms responsible; light and butterfly eyes.

PubMed

Truscott, R J W

2003-11-01

Age-related cataract is the leading cause of world blindness. Until recently, the biochemical mechanisms that result in human cataract formation have remained a mystery. In the case of nuclear cataract, it is becoming apparent that changes that take place within the lens at middle age may be ultimately responsible. The centre of the lens contains proteins that were synthesised prior to birth and while these crystallins are remarkably stable, it appears that an antioxidant environment may be necessary in order for them to remain soluble and for lens transparency. Once an internal barrier to the movement of small molecules, such as antioxidants, develops in the normal lens at middle age, the long-lived proteins in the lens centre become susceptible both to covalent attachment of reactive molecules, such as UV filters, and to oxidation. These processes of protein modification may, over time, lead inevitably to lens opacification and cataract.

Globe rupture with post cataract-surgery safety sunglasses.

PubMed

Brooks, Clifford W; Howard, Robert C; Lyons, Robert A; Reilly, Charles D

2010-07-01

We report a case of globe rupture associated with the use of post cataract-surgery protective eyewear. The patient had routine cataract surgery 3 months before presentation and had adapted his post cataract-surgery glasses to use on the tennis court. He experienced a large posterior globe rupture after falling directly onto his face during a match. Spectacle torsion is the suspected biomechanical process that led to the rupture. We conclude that although the glasses given to many patients after cataract surgery are protective for most low-impact injuries, patients should be aware they are not designed for activities with a risk for significant impact. Patients should also be counseled to use protective eyewear specifically designed and approved for the sport or activity in which they participate. No author has a financial or proprietary interest in any material or method mentioned. Published by Elsevier Inc.

A case control study of senile cataract in a hospital based population.

PubMed

Badrinath, S S; Sharma, T; Biswas, J; Srinivas, V

1996-12-01

A case-control study (244 cases and 264 controls) was done during 1986-89 on a hospital based population to evaluate the risk factors associated with the etiology of senile cataract. Patient with age between 40-60 years, visual acuity of 6/9 or less, and presence of lenticular opacity of senile origin were included as cases. Age matched individuals with absence of lenticular opacity made up the controls. Multivariate logistic regression analysis revealed that higher systolic BP and number of meals were significantly (P < or = 0.05) associated with presence of senile cataract; whereas higher weight, education and income, and utilization of cooking water had a significant protective effect against senile cataract. The present study helps the clinician to understand the possible risk factors associated with the development of senile cataract and could be helpful in designing a intervention strategy in future.

Cataract surgery in a case of carotid cavernous fistula

PubMed Central

Nair, Akshay Gopinathan; Praveen, Smita Vittal; Noronha, Veena Olma

2014-01-01

A carotid-cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system. The ocular manifestations include conjunctival chemosis, proptosis, globe displacement, raised intraocular pressure and optic neuropathy. Although management of CCF in these patients is necessary, the ophthalmologist may also have to treat other ocular morbidities such as cataract. Cataract surgery in patients with CCF may be associated with many possible complications, including suprachoroidal hemorrhage. We describe cataract extraction surgery in 60-year-old female with bilateral spontaneous low-flow CCF. She underwent phacoemulsification via a clear corneal route under topical anesthesia and had an uneventful postoperative phase and recovered successfully. Given the various possible ocular changes in CCF, one must proceed with an intraocular surgery with caution. In this communication, we wish to describe the surgical precautions and the possible pitfalls in cataract surgery in patients with CCF. PMID:25370401

Prenatal detection of congenital bilateral cataract leading to the diagnosis of Nance-Horan syndrome in the extended family.

PubMed

Reches, Adi; Yaron, Yuval; Burdon, Kathryn; Crystal-Shalit, Ornit; Kidron, Dvora; Malcov, Mira; Tepper, Ron

2007-07-01

To describe a family in which it was possible to perform prenatal diagnosis of Nance-Horan Syndrome (NHS). The fetus was evaluated by 2nd trimester ultrasound. The family underwent genetic counseling and ophthalmologic evaluation. The NHS gene was sequenced. Ultrasound demonstrated fetal bilateral congenital cataract. Clinical evaluation revealed other family members with cataract, leading to the diagnosis of NHS in the family. Sequencing confirmed a frameshift mutation (3908del11bp) in the NHS gene. Evaluation of prenatally diagnosed congenital cataract should include a multidisciplinary approach, combining experience and input from sonographer, clinical geneticist, ophthalmologist, and molecular geneticist.

Effect of coffee (caffeine) against human cataract blindness

PubMed Central

Varma, Shambhu D

2016-01-01

Previous biochemical and morphological studies with animal experiments have demonstrated that caffeine given topically or orally to certain experimental animal models has significant inhibitory effect on cataract formation. The present studies were undertaken to examine if there is a correlation between coffee drinking and incidence of cataract blindness in human beings. That has been found to be the case. Incidence of cataract blindness was found to be significantly lower in groups consuming higher amounts of coffee in comparison to the groups with lower coffee intake. Mechanistically, the caffeine effect could be multifactorial, involving its antioxidant as well as its bioenergetic effects on the lens. PMID:26869755

The willingness to pay for wait reduction: the disutility of queues for cataract surgery in Canada, Denmark, and Spain.

PubMed

Bishai, D M; Lang, H C

2000-03-01

We estimate demand curves for a one month reduction in waiting time for cataract surgery based on survey data collected in 1992 in Manitoba, Barcelona, and Denmark. Patients answered, "Would you be willing to pay [Bid, B] to reduce your waiting time for cataract surgery to less than one month?" Controlling for SES and visual status, Barcelonan patients have greater WTP for shortened waiting time than the Danes and Manitobans. We estimate the value (in 1992 $) of lost consumer surplus due to the cataract surgery queue at $128 per patient in Manitoba, $160 in Denmark, and $243 in Barcelona.

Eye fluke-induced cataracts in natural fish populations: is there potential for host manipulation?

PubMed

Seppälä, O; Karvonen, A; Valtonen, E T

2011-02-01

Manipulation of host phenotype (e.g. behaviour, appearance) is suggested to be a common strategy to enhance transmission in trophically transmitted parasites. However, in many systems, evidence of manipulation comes exclusively from laboratory studies and its occurrence in natural host populations is poorly understood. Here, we examined the potential for host manipulation by Diplostomum eye flukes indirectly by quantifying the physiological effects of parasites on fish. Earlier laboratory studies have shown that Diplostomum infection predisposes fish to predation by birds (definitive hosts of the parasites) by reducing fish vision through cataract formation. However, occurrence of cataracts and the subsequent potential for host manipulation in natural fish populations has remained poorly explored. We studied the occurrence of eye fluke-induced cataracts from 7 common fish species (Gymnocephalus cernuus, Rutilus rutilus, Leuciscus leuciscus, Alburnus alburnus, Osmerus eperlanus, Coregonus lavaretus and Gasterosteus aculeatus) from the Bothnian Bay in the Baltic Sea. We found that the parasite-induced cataracts were common in fish and they also reached high levels which are likely to predispose fish to predation. However, we observed such cataracts only in species with the highest parasite abundances, which suggests that only certain hosts may be strongly affected by the infection.

Achieving target refraction after cataract surgery.

PubMed

Simon, Shira S; Chee, Yewlin E; Haddadin, Ramez I; Veldman, Peter B; Borboli-Gerogiannis, Sheila; Brauner, Stacey C; Chang, Kenneth K; Chen, Sherleen H; Gardiner, Matthew F; Greenstein, Scott H; Kloek, Carolyn E; Chen, Teresa C

2014-02-01

To evaluate the difference between target and actual refraction after phacoemulsification and intraocular lens implantation at an academic teaching institution's Comprehensive Ophthalmology Service. Retrospective study. We examined 1275 eye surgeries for this study. All consecutive cataract surgeries were included if they were performed by an attending or resident surgeon from January through December 2010. Postoperative refractions were compared with preoperative target refractions. Patients were excluded if they did not have a preoperative target refraction documented or if they did not have a recorded postoperative manifest refraction within 90 days. The main outcome measure was percentage of cases achieving a postoperative spherical equivalent ± 1.0 diopter (D) of target spherical equivalent. We performed 1368 cataract surgeries from January through December of 2010. Of these, 1275 (93%) had sufficient information for analysis. Of the included cases, 94% (1196 of 1275) achieved ± 1.0 D of target refraction by 90 days after cataract surgery. This paper establishes a new benchmark for a teaching hospital, where 94% of patients achieved within 1.0 D of target refraction after cataract surgery. The refractive outcomes after cataract surgery at this academic teaching institution were higher than average international benchmarks. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Topical anesthesia for transpupillary silicone oil removal combined with cataract surgery.

PubMed

Jonas, Jost B; Hugger, Philipp; Sauder, Gangolf

2005-09-01

To assess safety of topical anesthesia for transpupillary silicone oil removal in combination with cataract surgery. Department of Ophthalmology Mannheim, University of Heidelberg, Mannheim, Germany. The clinical interventional study included 37 consecutive patients having transpupillary silicone oil removal combined with cataract surgery. Without exception, surgery was carried out in topical anesthesia for all patients. During the study period, there were no patients having transpupillary silicone oil removal in another type of local anesthesia than topical anesthesia. Topical anesthesia was achieved with oxybuprocaine 0.4% eyedrops installed 4 to 5 times prior to surgery. Cataract surgery was performed using the clear cornea technique with implantation of a foldable intraocular posterior chamber lens. Silicone oil was released through a planned posterior capsulotomy during cataract surgery prior to implantation of the intraocular lens (IOL). For all patients, surgery could be carried out in topical anesthesia without switching to peribulbar or any other type of anesthesia. None of the patients complained about severe pain intraoperatively or postoperatively. No severe complications such as expulsive hemorrhage, luxation of the IOL, or iris incarceration were encountered in any of the surgeries. Transpupillary silicone oil through a planned posterior capsulotomy during cataract surgery may be performed in topical surgery.

Reprint of: Relationship between cataract severity and socioeconomic status.

PubMed

Wesolosky, Jason D; Rudnisky, Christopher J

2015-06-01

To determine the relationship between cataract severity and socioeconomic status (SES). Retrospective, observational case series. A total of 1350 eyes underwent phacoemulsification cataract extraction by a single surgeon using an Alcon Infiniti system. Cataract severity was measured using phaco time in seconds. SES was measured using area-level aggregate census data: median income, education, proportion of common-law couples, and employment rate. Preoperative best corrected visual acuity was obtained and converted to logarithm of the minimum angle of resolution values. For patients undergoing bilateral surgery, the generalized estimating equation was used to account for the correlation between eyes. Univariate analyses were performed using simple regression, and multivariate analyses were performed to account for variables with significant relationships (p < 0.05) on univariate testing. Sensitivity analyses were performed to assess the effect of including patient age in the controlled analyses. Multivariate analyses demonstrated that cataracts were more severe when the median income was lower (p = 0.001) and the proportion of common-law couples living in a patient's community (p = 0.012) and the unemployment rate (p = 0.002) were higher. These associations persisted even when controlling for patient age. Patients of lower SES have more severe cataracts. Copyright © 2015. Published by Elsevier Inc.

Loupe magnification for small incision cataract surgery--an alternative to microscope magnification?

PubMed

Singh, S K; Winter, I; Hennig, A

2008-01-01

A Prospective randomized controlled study was conducted to compare outcome of Small Incision Cataract Surgery (SICS) using microscope or loupe magnification. Two hundred fifty one patient with mature cataract were randomly allocated to SICS-Fishhook Technique with either microscope (127 eyes) or loupe (124 eyes) magnification. Intra- and postoperative complications and immediate visual outcome were analyzed. Nearly two third (microscope 65% and magnifying loupe 62.9%) of all patients had good visual outcome on first postoperative day. Poor outcome (<6/60) was recorded in 8% (microscope group) and 7% (magnifying loupe group). Mean visual acuity with Snellen was 0.39 (SD 0.2) in microscope group and 0.38 (SD 0.2) in magnifying loupe group. Intra operative complications were comparable in both groups. Mean surgery time with loupe magnification was significantly shorter. Comparatively equivalent good surgical outcome was achieved with loupe as well as with microscope magnification. However performing SICS with loupe magnification is significantly faster. Small incision cataract surgery with loupe magnification is safe and effective procedure for cataract surgery so it can play a role in reducing cataract blindness in developing countries of the world.

A Novel Form of “Central Pouchlike” Cataract, with Sutural Opacities, Maps to Chromosome 15q21-22

PubMed Central

Vanita; Singh, Jai Rup; Sarhadi, Virinder K.; Singh, Daljit; Reis, André; Rueschendorf, Franz; Becker-Follmann, Johannes; Jung, Martin; Sperling, Karl

2001-01-01

Congenital cataract is a clinically and genetically highly heterogeneous eye disorder, with autosomal dominant inheritance being most common. We investigated a large seven-generation family with 74 individuals affected by autosomal dominant congenital cataract (ADCC). The phenotype in this family can be described as “central pouchlike” cataract with sutural opacities, and it differs from the other mapped cataracts. We performed linkage analysis with microsatellite markers in this family and excluded the known candidate genes. A genomewide search revealed linkage to markers on chromosome 15, with a maximum two-point LOD score of 5.98 at θ=0 with marker D15S117. Multipoint analysis also gave a maximum LOD score of 5.98 at D15S117. Multipoint and haplotype analysis narrowed the cataract locus to a 10-cM region between markers D15S209 and D15S1036, closely linked to marker D15S117 in q21-q22 region of chromosome 15. This is the first report of a gene for a clinically new type of ADCC at 15q21-22 locus. PMID:11133359

Demographic characteristics and visual status of patients undergoing cataract surgery at a tertiary hospital in Kano, Nigeria.

PubMed

Kurawa, Musbahu Sani; Abdu, Lawan

2017-01-01

Objective/Purpose: To describe the demographic and baseline ocular characteristics, prevalence of blindness and visual impairment among patients undergoing extracapsular cataract extraction for age related cataract at the study hospital over a one year period. Materials/Patients: All consecutive patients aged 40 years and above identified with age related cataract in one or both eyes who voluntarily agree to participate were included. The study adhered to the tenets of the Helsinki declaration. Written informed consent was obtained from all eligible patients. All patients underwent basic eye examination by the ophthalmologist. Visual impairment was determined for each eye according to the standard WHO categorizations. Information obtained also included age, sex and history of previous cataract surgery. Data were recorded in manual tally sheets and on modified computer Cataract Surgery Record forms. Analyses were done using SPSS (version 16, SPSS Inc., Chicago, USA). The participation rate was 91.2%. There were 495 eyes of 487 consecutive patients. This include 212 males and 275 females (M:F, 1:1.3). The age range was 40 to 99 years with a mean age of 62.76 ± 10.49 years (61.35 ± 9.75 years in men and 63.85±10.9 years in females). Most of the patients (n = 451; 92.6%, 95% CI: 89.9-94.6%) were aged 50 years and above. Sixty patients (12.3%, 95% CI: 9.6-15.5%) had cataract in both eyes, 427 (87.7%, 95% CI: 84.5-90.3%) were in one eye. Among these, preoperatively 16 (3.3%, 95% CI: 2.0-5.3%) had aphakia, 21 (4.3%, 95% CI: 2.8-6.5%) had uniocular pseudophakia. About 63.2% (95% CI: 58.9-67.4%) of patients had normal vision in the better eye (presenting VA ≥6/18). Overall 9.5% (95% CI: 7.3-12.7%) were bilaterally blind. About 96.8% of eyes (95% CI: 94.5-98.0%) undergoing cataract surgery were blind (presenting VAConclusion: The study highlights preponderance of females and high incidence of blinding cataract. Education and early disease awareness may play an important role in these patients and could improve cataract surgical services in our hospital..

Surgery for post-vitrectomy cataract

PubMed Central

Do, Diana V; Gichuhi, Stephen; Vedula, Satyanarayana S; Hawkins, Barbara S

2014-01-01

Background Cataract formation or acceleration can occur after intraocular surgery, especially following vitrectomy, a surgical technique for removing the vitreous which is used in the treatment of disorders that affect the posterior segment of the eye. The underlying problem that led to vitrectomy may limit the benefit from cataract surgery. Objectives The objective of this review was to evaluate the effectiveness and safety of surgery for post-vitrectomy cataract with respect to visual acuity, quality of life, and other outcomes. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 4), Ovid MEDLINE, Ovid MEDLINE in-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily Update, Ovid OLDMED-LINE (January 1946 to May 2013), EMBASE (January 1980 to May 2013, Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to May 2013), PubMed (January 1946 to May 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 May 2013. Selection criteria We planned to include randomized and quasi-randomized controlled trials comparing cataract surgery with no surgery in adult patients who developed cataract following vitrectomy. Data collection and analysis Two authors screened the search results independently according to the standard methodological procedures expected by The Cochrane Collaboration. Main results We found no randomized or quasi-randomized controlled trials comparing cataract surgery with no cataract surgery for patients who developed cataracts following vitrectomy surgery. Authors' conclusions There is no evidence from randomized or quasi-randomized controlled trials on which to base clinical recommendations for surgery for post-vitrectomy cataract. There is a clear need for randomized controlled trials to address this evidence gap. Such trials should stratify participants by their age, the retinal disorder leading to vitrectomy, and the status of the underlying disease process in the contralateral eye. Outcomes assessed in such trials may include gain of vision on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, quality of life, and adverse events such as posterior capsular rupture. Both short-term (six-month) and long-term (one-year or two-year) outcomes should be examined. PMID:24357418

Influence of galactose cataract on erythrocytic and lenticular glutathione metabolism in albino rats.

PubMed

Jyothi, M; Sanil, R; Shashidhar, S

2011-01-01

Glutathione depletion has been postulated to be the prime reason for galactose cataract. The current research seeks the prospect of targeting erythrocytes to pursue the lens metabolism by studying the glutathione system. To study the activity of the glutathione-linked scavenger enzyme system in the erythrocyte and lens of rats with cataract. Experiments were conducted in 36 male albino rats weighing 80 ± 20 g of 28 days of age. The rats were divided into two major groups, viz. experimental and control. Six rats in each group were sacrificed every 10 days, for 30 days. Cataract was induced in the experimental group by feeding the rats 30% galactose (w/w). The involvement of reduced glutathione (GSH) and the linked enzymes was studied in the erythrocytes and lens of cataractous as well as control rats. Parametric tests like one-way ANOVA and Student's 't' test were used for comparison. Correlation linear plot was used to compare the erythrocyte and lens metabolism. The concentration of GSH and the activity of linked enzymes were found decreased with the progression of cataract, and also in comparison to the control. The same linear fashion was also observed in the erythrocytes. Depletion of GSH was the prime factor for initiating galactose cataract in the rat model. This depletion may in turn result in enzyme inactivation leading to cross-linking of protein and glycation. The correlation analysis specifies that the biochemical mechanism in the erythrocytes and lens is similar in the rat model.

[Study of free radicals in aqueous humor in glaucoma and cataracts: differences in presence or absence of diabetes mellitus and neovascular glaucoma].

PubMed

Oshida, Eiki; Arai, Kiyomi; Sakai, Miki; Chikuda, Makoto

2014-09-01

This study was conducted for the purpose of comparing differences in the types of free radicals in the aqueous humor of glaucoma and cataract patients. Free radicals in the aqueous humor of 44 glaucoma eyes and 15 cataract eyes were measured by electron spin resonance (ESR), followed by comparing the detection rates. In addition, subgroup analyses were also conducted for the presence or absence of complications of diabetes mellitus (DM) and neovascular glaucoma (NVG) in the patients. Three types of free radicals were measured, ascorbate-free radical (AFR), AFR containing a trace amount of superoxide (SO) (AFR +), and SO containing a trace amount of AFR (SO +). Significant differences were observed in the detection rates of each type between the glaucoma group (maximum SO +) and the cataract group (maximum AFR), between the DM group (maximum SO +) and the non-DM group (maximum AFR) in the glaucoma, and between the DM group (maximum AFR +) and the non-DM group (maximum AFR) in the cataract. SO + was detected in all cases of NVG regardless of whether they were DM or non-DM. Glaucoma cases are more susceptible to the generation of SO in the aqueous humor than cataracts, and they are more liable to occur in DM than in non-DM in both glaucoma and cataract cases. This study suggest an evidence for a strong correlation with SO and vascularization in NVG.

Association of presenile cataract with galactose-1-phosphate uridyl transferase gene mutations.

PubMed

Nema, Nitin; Kumar, Ravindra; Verma, Abha; Verma, Sonam; Chaturvedi, Kiran

2017-01-01

Presenile cataract is commonly idiopathic in origin. However, patients with presenile cataract could have an underlying genetic abnormality of galactose metabolism. We studied the association, if any, between idiopathic presenile cataract and galactose-1 -phosphate uridyl transferase (GALT) gene mutation. We selected 50 patients with idiopathic presenile cataract, <45 years of age, and 50 age- and sex-matched controls for the study. Mutations in the GALT gene were determined by polymerase chain reaction restriction fragment length polymorphism. The classical galactosaemia was characterized by Q188R and K285N mutations, whereas Duarte galactosaemia by N314D mutations (Duarte-2: N314D with IVS5-24G >A and Duarte-1: N314D without IVS5- 24G>A). The most common mutation observed was the N314D (Duarte) mutation. The frequencies of classical and N31 4D alleles in patients with presenile cataract (16%) and controls (26%) were not statistically different (p=0.32, OR 0.54, 95% CI 0.20-1.45). Similarly, there was no statistically significant difference in the frequency distribution of Duarte-1 (p=0.77, OR 0.77, 95% CI 0.23-0.24) and Duarte-2 (p=0.44, OR 0.38, 95% CI 0.07-2.03) galactosaemia mutations in patients and controls. Duarte galactosaemia, a milder form of the disease, is more common than classical galactosaemia in the Indian population. Duarte galactosaemia is unlikely to be a causative factor in presenile cataract.

Effect of cataract surgery and pupil dilation on iris pattern recognition for personal authentication.

PubMed

Dhir, L; Habib, N E; Monro, D M; Rakshit, S

2010-06-01

The purpose of this study was to investigate the effect of cataract surgery and pupil dilation on iris pattern recognition for personal authentication. Prospective non-comparative cohort study. Images of 15 subjects were captured before (enrolment), and 5, 10, and 15 min after instillation of mydriatics before routine cataract surgery. After cataract surgery, images were captured 2 weeks thereafter. Enrolled and test images (after pupillary dilation and after cataract surgery) were segmented to extract the iris. This was then unwrapped onto a rectangular format for normalization and a novel method using the Discrete Cosine Transform was applied to encode the image into binary bits. The numerical difference between two iris codes (Hamming distance, HD) was calculated. The HD between identification and enrolment codes was used as a score and was compared with a confidence threshold for specific equipment, giving a match or non-match result. The Correct Recognition Rate (CRR) and Equal Error Rates (EERs) were calculated to analyse overall system performance. After cataract surgery, perfect identification and verification was achieved, with zero false acceptance rate, zero false rejection rate, and zero EER. After pupillary dilation, non-elastic deformation occurs and a CRR of 86.67% and EER of 9.33% were obtained. Conventional circle-based localization methods are inadequate. Matching reliability decreases considerably with increase in pupillary dilation. Cataract surgery has no effect on iris pattern recognition, whereas pupil dilation may be used to defeat an iris-based authentication system.

Comparison of the efficacy and patients' tolerability of Nepafenac and Ketorolac in the treatment of ocular inflammation following cataract surgery: A meta-analysis of randomized controlled trials.

PubMed

Zhao, Xinyu; Xia, Song; Wang, Erqian; Chen, Youxin

2017-01-01

As a new ophthalmic non-steroidal anti-inflammatory drug (NSAID) with prodrug structure, Nepafenac was supposed to have a better efficacy than conventional NSAIDs both in patients' tolerability and ocular inflammation associated with cataract surgery. However, many current studies reached contradictory conclusions on the superiority of Nepafenac over Ketorolac. The objective of our study is to evaluate the efficacy and patients' tolerability of Nepafenac and Ketorolac following cataract surgery. To clarify this, we conducted a meta-analysis of randomized controlled trials. Eleven articles were included in this study. The dataset consisted of 1165 patients, including 1175 cataract surgeries. Among them, 574 patients were in the Nepafenac group and 591 in the Ketorolac group. Our analysis indicated that these two drugs were equally effective in controlling post cataract surgery ocular inflammation, reducing macular edema, achieving a better visual ability and maintaining intraoperative mydriasis during cataract surgery. However, Nepafenac was more effective than Ketorolac in reducing the incidence of postoperative conjunctival hyperemia and ocular discomfort. This meta-analysis indicated that topical Nepafenac is superior to Ketorolac in patients' tolerability following cataract surgery. However, these two drugs are equally desirable in the management of anterior chamber inflammation, visual rehabilitation and intraoperative mydriasis. Given the limitations in our study, more researches with larger sample sizes and focused on more specific indicators such as peak aqueous concentrations of drugs or PEG2 levels are required to reach a firmer conclusion.

A population based eye survey of older adults in Tirunelveli district of south India: blindness, cataract surgery, and visual outcomes

PubMed Central

Nirmalan, P K; Thulasiraj, R D; Maneksha, V; Rahmathullah, R; Ramakrishnan, R; Padmavathi, A; Munoz, S R; Ellwein, L B

2002-01-01

Aims: To assess the prevalence of vision impairment, blindness, and cataract surgery and to evaluate visual acuity outcomes after cataract surgery in a south Indian population. Methods: Cluster sampling was used to randomly select a cross sectional sample of people ≥50 years of age living in the Tirunelveli district of south India. Eligible subjects in 28 clusters were enumerated through a door to door household survey. Visual acuity measurements and ocular examinations were performed at a selected site within each of the clusters in early 2000. The principal cause of visual impairment was identified for eyes with presenting visual acuity <6/18. Independent replicate testing for quality assurance monitoring was performed in subjects with reduced vision and in a sample of those with normal vision for six of the study clusters. Results: A total of 5795 people in 3986 households were enumerated and 5411 (93.37%) were examined. The prevalence of presenting and best corrected visual acuity ≥6/18 in both eyes was 59.4% and 75.7%, respectively. Presenting vision <6/60 in both eyes (the definition of blindness in India) was found in 11.0%, and in 4.6% with best correction. Presenting blindness was associated with older age, female sex, and illiteracy. Cataract was the principal cause of blindness in at least one eye in 70.6% of blind people. The prevalence of cataract surgery was 11.8%—with an estimated 56.5% of the cataract blind already operated on. Surgical coverage was inversely associated with illiteracy and with female sex in rural areas. Within the cataract operated sample, 31.7% had presenting visual acuity ≥6/18 in both eyes and 11.8% were <6/60; 40% were bilaterally operated on, with 63% pseudophakic. Presenting vision was <6/60 in 40.7% of aphakic eyes and in 5.1% of pseudophakic eyes; with best correction the percentages were 17.6% and 3.7%, respectively. Refractive error, including uncorrected aphakia, was the main cause of visual impairment in cataract operated eyes. Vision <6/18 was associated with cataract surgery in government, as opposed to that in non-governmental/private facilities. Age, sex, literacy, and area of residence were not predictors of visual outcomes. Conclusion: Treatable blindness, particularly that associated with cataract and refractive error, remains a significant problem among older adults in south Indian populations, especially in females, the illiterate, and those living in rural areas. Further study is needed to better understand why a significant proportion of the cataract blind are not taking advantage of free of charge eye care services offered by the Aravind Eye Hospital and others in the district. While continuing to increase cataract surgical volume to reduce blindness, emphasis must also be placed on improving postoperative visual acuity outcomes. PMID:11973242

Virtual Mentor Cataract Surgery Trainer

DTIC Science & Technology

2010-09-01

absence, assess for notable lenticular astigmatism ** How and when do you decide to use a capsular tension ring? (Expert) Zonular dialysis noted on...TITLE: Virtual Mentor Cataract Surgery Trainer PRINCIPAL INVESTIGATOR: Principal Investigator: John I. Loewenstein MD Co-Investigator: Bonnie A...AND SUBTITLE Virtual Mentor Cataract Surgery Trainer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-08-1-0531 5c. PROGRAM ELEMENT NUMBER

Globular bodies: a primary cause of the opacity in senile and diabetic posterior cortical subcapsular cataracts?

PubMed

Creighton, M O; Trevithick, J R; Mousa, G Y; Percy, D H; McKinna, A J; Dyson, C; Maisel, H; Bradley, R

1978-07-01

We examined 9 cataracts from maturity onset diabetics and 4 senile posterior subcapsular cataracts by scanning electron microscopy, transmission electron microscopy, immunofluorescence for crystallin proteins and actin, histochemical methods and x-ray diffraction. The cataractous regions contained spherical globules up to 20 mu in diameter, often in a fibrous matrix. Some were extracellular Morgagnian globules, apparently formed by blebbing from the cell surface; others appeared to have been formed intracellularly. The area of globular degeneration was usually 300 mu deep, but had deeper fusiform extensions. Morphological changes in the cell cytoplasm varied according to their depth in the cataract. Electron microscopy showed intracellular and extracellular globules, many of them were bounded by lipid bilayer membranes. Immunofluorescent staining showed that all the globules contained gamma-crystallin; some contained alpha- and beta-crystallins and actin. All the globules contained higher concentrations of cysteine or cystine than the surrounding lens tissue but they did not react to stains for carbohydrate or calcium. X-ray diffraction studies showed that crystalline calcium salts were absent. Globules and cavities averaged 45% of the total area in cross section. Assuming an area of cataract to be 300 micron thick and that globules 1 mu in diameter scattered, while 2--20 mu in diameter reflected light, we calculated that light passing through such a thickness would be reduced by 65%. Thus the globules could account for most of the opacity of the cataractous area. Presumably the fibrous degeneration of the cells causes enough light scattering to account for the remainder of the reduction. Cataract patients complain of decreased visual acuity, a golden halo around objects, and difficulties when driving while facing oncoming traffic at night. These probably result from light scattering. In our previous experiments, globular bodies containing gamma-crystallin were found in cells grown in tissue culture, and blebs with increased acitn content similar to Morgagnian globules were formed in tissue culture by treating differentiated rat lens cells of stage 2 by cytochalasin D (which impaired microfilament function). These results suggest the possibility of simulating in tissue culture the morphological alterations seen in the cataractous cell.