Investigating the role of visual and auditory search in reading and developmental dyslexia

PubMed Central

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-01-01

It has been suggested that auditory and visual sequential processing deficits contribute to phonological disorders in developmental dyslexia. As an alternative explanation to a phonological deficit as the proximal cause for reading disorders, the visual attention span hypothesis (VA Span) suggests that difficulties in processing visual elements simultaneously lead to dyslexia, regardless of the presence of a phonological disorder. In this study, we assessed whether deficits in processing simultaneously displayed visual or auditory elements is linked to dyslexia associated with a VA Span impairment. Sixteen children with developmental dyslexia and 16 age-matched skilled readers were assessed on visual and auditory search tasks. Participants were asked to detect a target presented simultaneously with 3, 9, or 15 distracters. In the visual modality, target detection was slower in the dyslexic children than in the control group on a “serial” search condition only: the intercepts (but not the slopes) of the search functions were higher in the dyslexic group than in the control group. In the auditory modality, although no group difference was observed, search performance was influenced by the number of distracters in the control group only. Within the dyslexic group, not only poor visual search (high reaction times and intercepts) but also low auditory search performance (d′) strongly correlated with poor irregular word reading accuracy. Moreover, both visual and auditory search performance was associated with the VA Span abilities of dyslexic participants but not with their phonological skills. The present data suggests that some visual mechanisms engaged in “serial” search contribute to reading and orthographic knowledge via VA Span skills regardless of phonological skills. The present results further open the question of the role of auditory simultaneous processing in reading as well as its link with VA Span skills. PMID:24093014

Investigating the role of visual and auditory search in reading and developmental dyslexia.

PubMed

Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

2013-01-01

It has been suggested that auditory and visual sequential processing deficits contribute to phonological disorders in developmental dyslexia. As an alternative explanation to a phonological deficit as the proximal cause for reading disorders, the visual attention span hypothesis (VA Span) suggests that difficulties in processing visual elements simultaneously lead to dyslexia, regardless of the presence of a phonological disorder. In this study, we assessed whether deficits in processing simultaneously displayed visual or auditory elements is linked to dyslexia associated with a VA Span impairment. Sixteen children with developmental dyslexia and 16 age-matched skilled readers were assessed on visual and auditory search tasks. Participants were asked to detect a target presented simultaneously with 3, 9, or 15 distracters. In the visual modality, target detection was slower in the dyslexic children than in the control group on a "serial" search condition only: the intercepts (but not the slopes) of the search functions were higher in the dyslexic group than in the control group. In the auditory modality, although no group difference was observed, search performance was influenced by the number of distracters in the control group only. Within the dyslexic group, not only poor visual search (high reaction times and intercepts) but also low auditory search performance (d') strongly correlated with poor irregular word reading accuracy. Moreover, both visual and auditory search performance was associated with the VA Span abilities of dyslexic participants but not with their phonological skills. The present data suggests that some visual mechanisms engaged in "serial" search contribute to reading and orthographic knowledge via VA Span skills regardless of phonological skills. The present results further open the question of the role of auditory simultaneous processing in reading as well as its link with VA Span skills.

Neural dissociation of phonological and visual attention span disorders in developmental dyslexia: FMRI evidence from two case reports.

PubMed

Peyrin, C; Lallier, M; Démonet, J F; Pernet, C; Baciu, M; Le Bas, J F; Valdois, S

2012-03-01

A dissociation between phonological and visual attention (VA) span disorders has been reported in dyslexic children. This study investigates whether this cognitively-based dissociation has a neurobiological counterpart through the investigation of two cases of developmental dyslexia. LL showed a phonological disorder but preserved VA span whereas FG exhibited the reverse pattern. During a phonological rhyme judgement task, LL showed decreased activation of the left inferior frontal gyrus whereas this region was activated at the level of the controls in FG. Conversely, during a visual categorization task, FG demonstrated decreased activation of the parietal lobules whereas these regions were activated in LL as in the controls. These contrasted patterns of brain activation thus mirror the cognitive disorders' dissociation. These findings provide the first evidence for an association between distinct brain mechanisms and distinct cognitive deficits in developmental dyslexia, emphasizing the importance of taking into account the heterogeneity of the reading disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

Being First Matters: Topographical Representational Similarity Analysis of ERP Signals Reveals Separate Networks for Audiovisual Temporal Binding Depending on the Leading Sense

PubMed Central

2017-01-01

In multisensory integration, processing in one sensory modality is enhanced by complementary information from other modalities. Intersensory timing is crucial in this process because only inputs reaching the brain within a restricted temporal window are perceptually bound. Previous research in the audiovisual field has investigated various features of the temporal binding window, revealing asymmetries in its size and plasticity depending on the leading input: auditory–visual (AV) or visual–auditory (VA). Here, we tested whether separate neuronal mechanisms underlie this AV–VA dichotomy in humans. We recorded high-density EEG while participants performed an audiovisual simultaneity judgment task including various AV–VA asynchronies and unisensory control conditions (visual-only, auditory-only) and tested whether AV and VA processing generate different patterns of brain activity. After isolating the multisensory components of AV–VA event-related potentials (ERPs) from the sum of their unisensory constituents, we ran a time-resolved topographical representational similarity analysis (tRSA) comparing the AV and VA ERP maps. Spatial cross-correlation matrices were built from real data to index the similarity between the AV and VA maps at each time point (500 ms window after stimulus) and then correlated with two alternative similarity model matrices: AVmaps = VAmaps versus AVmaps ≠ VAmaps. The tRSA results favored the AVmaps ≠ VAmaps model across all time points, suggesting that audiovisual temporal binding (indexed by synchrony perception) engages different neural pathways depending on the leading sense. The existence of such dual route supports recent theoretical accounts proposing that multiple binding mechanisms are implemented in the brain to accommodate different information parsing strategies in auditory and visual sensory systems. SIGNIFICANCE STATEMENT Intersensory timing is a crucial aspect of multisensory integration, determining whether and how inputs in one modality enhance stimulus processing in another modality. Our research demonstrates that evaluating synchrony of auditory-leading (AV) versus visual-leading (VA) audiovisual stimulus pairs is characterized by two distinct patterns of brain activity. This suggests that audiovisual integration is not a unitary process and that different binding mechanisms are recruited in the brain based on the leading sense. These mechanisms may be relevant for supporting different classes of multisensory operations, for example, auditory enhancement of visual attention (AV) and visual enhancement of auditory speech (VA). PMID:28450537

Impaired letter-string processing in developmental dyslexia: what visual-to-phonology code mapping disorder?

PubMed

Valdois, Sylviane; Lassus-Sangosse, Delphine; Lobier, Muriel

2012-05-01

Poor parallel letter-string processing in developmental dyslexia was taken as evidence of poor visual attention (VA) span, that is, a limitation of visual attentional resources that affects multi-character processing. However, the use of letter stimuli in oral report tasks was challenged on its capacity to highlight a VA span disorder. In particular, report of poor letter/digit-string processing but preserved symbol-string processing was viewed as evidence of poor visual-to-phonology code mapping, in line with the phonological theory of developmental dyslexia. We assessed here the visual-to-phonological-code mapping disorder hypothesis. In Experiment 1, letter-string, digit-string and colour-string processing was assessed to disentangle a phonological versus visual familiarity account of the letter/digit versus symbol dissociation. Against a visual-to-phonological-code mapping disorder but in support of a familiarity account, results showed poor letter/digit-string processing but preserved colour-string processing in dyslexic children. In Experiment 2, two tasks of letter-string report were used, one of which was performed simultaneously to a high-taxing phonological task. Results show that dyslexic children are similarly impaired in letter-string report whether a concurrent phonological task is simultaneously performed or not. Taken together, these results provide strong evidence against a phonological account of poor letter-string processing in developmental dyslexia. Copyright © 2012 John Wiley & Sons, Ltd.

Impact of orthographic transparency on typical and atypical reading development: evidence in French-Spanish bilingual children.

PubMed

Lallier, Marie; Valdois, Sylviane; Lassus-Sangosse, Delphine; Prado, Chloé; Kandel, Sonia

2014-05-01

The present study aimed to quantify cross-linguistic modulations of the contribution of phonemic awareness skills and visual attention span (VA Span) skills (number of visual elements that can be processed simultaneously) to reading speed and accuracy in 18 Spanish-French balanced bilingual children with and without developmental dyslexia. The children were administered two similar reading batteries in French and Spanish. The deficits of the dyslexic children in reading accuracy were mainly visible in their opaque orthography (French) whereas difficulties indexed by reading speed were observed in both their opaque and transparent orthographies. Dyslexic children did not exhibit any phonemic awareness problems in French or in Spanish, but showed poor VA Span skills compared to their control peers. VA span skills correlated with reading accuracy and speed measures in both Spanish and French, whereas phonemic awareness correlated with reading accuracy only. Overall, the present results show that the VA Span is tightly related to reading speed regardless of orthographic transparency, and that it accounts for differences in reading performance between good and poor readers across languages. The present findings further suggest that VA Span skills may play a particularly important role in building-up specific word knowledge which is critical for lexical reading strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

PubMed Central

Lobier, Muriel A.; Peyrin, Carole; Pichat, Cédric; Le Bas, Jean-François; Valdois, Sylviane

2014-01-01

The visual attention (VA) span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT) in dyslexia have yet to be explored. Using functional magnetic resonance imaging, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric), similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL) activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined regions of interest, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity was related to vOT activity in each group. In the left hemisphere, SPL activity covaried with vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity covaried with vOT activity only for dyslexic readers. These results bring critical support to the VA interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia. PMID:25071509

Local and non-local deficits in amblyopia: acuity and spatial interactions.

PubMed

Bonneh, Yoram S; Sagi, Dov; Polat, Uri

2004-12-01

Amblyopic vision is thought to be limited by abnormal long-range spatial interactions, but their exact mode of action and relationship to the main amblyopic deficit in visual acuity is largely unknown. We studied this relationship in a group (N=59) of anisometropic (N=21) and strabismic (or combined, N=38) subjects, using (1) a single and multi-pattern (crowded) computerized static Tumbling-E test with scaled spacing of two pattern widths (TeVA), in addition to an optotype (ETDRS chart) acuity test (VA) and (2) contrast detection of Gabor patches with lateral flankers (lateral masking) along the horizontal and vertical axes as well as in collinear and parallel configurations. By correlating the different measures of visual acuity and contrast suppression, we found that (1) the VA of the strabismic subjects could be decomposed into two uncorrelated components measured in TeVA: acuity for isolated patterns and acuity reduction due to flanking patterns. The latter comprised over 60% of the VA magnitude, on the average and accounted for over 50% of its variance. In contrast, a slight reduction in acuity was found in the anisometropic subjects, and the acuity for a single pattern could account for 70% of the VA variance. (2) The lateral suppression (contrast threshold elevation) in a parallel configuration along the horizontal axis was correlated with the VA (R2=0.7), as well as with the crowding effect (TeVA elevation, R2=0.5) for the strabismic group. Some correlation with the VA was also found for the collinear configuration in the anisometropic group, but less suppression and no correlation were found for all the vertical configurations in all the groups. The results indicate the existence of a specific non-local component of the strabismic deficit, in addition to the local acuity deficit in all amblyopia types. This deficit might reflect long-range lateral inhibition, or alternatively, an inaccurate and scattered top-down attentional selection mechanism.

A nationwide population-based survey on visual acuity, near vision, and self-reported visual function in the adult population in Finland.

PubMed

Laitinen, Arja; Koskinen, Seppo; Härkänen, Tommi; Reunanen, Antti; Laatikainen, Leila; Aromaa, Arpo

2005-12-01

To estimate the prevalence rates of habitual visual acuity (VA) levels and visual impairment in Finland and to assess their correlation with self-reported visual function. Cross-sectional population-based study. Subjects were selected randomly from the Finnish population aged 30 years or older. Of 7979 eligible people, 7393 (93%) were interviewed, 6771 (85%) were examined, and 6663 (84%) had distance VA assessed. Participants underwent a home interview and a comprehensive examination including measuring binocular VA for distance and for near with the participants' current spectacles, if any. The level of VA for distance and for near with current spectacle correction. The self-reported capability to read newsprint and television text and the ability to move about without being restricted by reduced vision. The prevalence of good to moderate VA for distance (VA> or =0.5 [> or =20/40]) measured with current spectacles was 95.9%, and 87.4% had a VA level of 0.8 (20/25) or better. The prevalence of habitual visual impairment (VA< or =0.25 [< or =20/80]) was 1.6%, and 0.5% were blind (VA<0.1 [<20/200]). The prevalence of visual impairment increased significantly with age (P<0.001), especially in the age group of 65 to 74 years and upward. There was no gender difference in VA for distance, but decreased near vision (VA< or =0.25 [< or =20/80]) was significantly more common in men than in women (P<0.01). By applying the imputated numbers of visually impaired and blind participants to the Finnish population (approximately 3 million aged 30 years or older), there were approximately 65000 (2.1%) visually impaired and 17000 (0.6%) blind adult persons in the country in 2000. The correlation between self-reported visual ability and measured visual function was moderate but statistically significant (r = 0.27-0.40; P<0.0001). The proportion of people with reading difficulties or who were unable to read newsprint has decreased 7% during the last 2 decades. Functional visual impairment increased with age especially in the age group of 65 to 74 years and upward and was as prevalent in women as in men. The prevalence of people with reading difficulties has decreased considerably since 1980.

The impact of visual impairment on self-reported visual functioning in Latinos: The Los Angeles Latino Eye Study.

PubMed

Globe, Denise R; Wu, Joanne; Azen, Stanley P; Varma, Rohit

2004-06-01

To assess the association between presenting binocular visual acuity (VA) and self-reported visual function as measured by the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). A population-based, prevalence study of eye disease in Latinos 40 years and older residing in La Puente, California (Los Angeles Latino Eye Study [LALES]). Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in La Puente. All participants completed a standardized interview, including the NEI-VFQ-25 to measure visual functioning, and a detailed eye examination. Two definitions of visual impairment were used: (1) presenting binocular distance VA of 20/40 or worse and (2) presenting binocular distance VA worse than 20/40. Analysis of variance was used to determine any systematic differences in mean NEI-VFQ-25 scores by visual impairment. Regression analyses were completed (1) to determine the association of age, gender, number of systemic comorbidities, depression, and VA with self-reported visual function and (2) to estimate a visual impairment-related difference for each subscale based on differences in VA. The NEI-VFQ-25 scores in persons with visual impairment. Of the 5287 LALES participants with complete NEI-VFQ-25 data, 6.3% (including 20/40) and 4.2% (excluding 20/40) were visually impaired. In the visually impaired participants, the NEI-VFQ-25 subscale scores ranged from 46.2 (General Health) to 93.8 (Color Vision). In the regression model, only VA, depression, and number of comorbidities were significantly associated with all subscale scores (R(2) ranged from 0.09 for Ocular Pain to 0.33 for the composite score). For 9 of 11 subscales, a 5-point change was equivalent to a 1- or 2-line difference in VA. Relationships were similar regardless of the definition of visual impairment. In this population-based study of Latinos, the NEI-VFQ-25 was sensitive to differences in VA. A 5-point difference on the NEI-VFQ-25 seems to be a minimal criterion for a visual impairment-related difference. Self-reported visual function is essentially unchanged if the definition of visual impairment includes or excludes a VA of 20/40.

The correlation between visual acuity and color vision as an indicator of the cause of visual loss.

PubMed

Almog, Yehoshua; Nemet, Arie

2010-06-01

To explore the correlation between visual acuity (VA) and color vision and to establish a guide for the diagnosis of the cause of visual loss based on this correlation. Retrospective comparative evaluation of a diagnostic test. A total of 259 patients with visual impairment caused by 1 of 4 possible disease categories were included. Patients were divided into 4 groups according to the etiology of visual loss: 1) optic neuropathies, 2) macular diseases, 3) media opacities, and 4) amblyopia. The best-corrected VA was established and a standard Ishihara 15 color plates was tested and correlated to the VA in every group separately. Correlation between the VA and the color vision along the different etiologies was evaluated. Frequency of each combination of color vision and VA in every disease category was established. VA is correlated with color vision in all 4 disease categories. For the same degree of VA loss, patients with optic neuropathy are most likely and patients with amblyopia are the least expected to have a significant color vision loss. Patients with optic neuropathy had considerably worse average color vision (6.7/15) compared to patients in the other 3 disease categories: 11.1/15 (macular diseases), 13.2/15 (media opacities), and 13.4/15 (amblyopia). Diseases of the optic nerve affect color vision earlier and more profoundly than other diseases. When the cause of visual loss is uncertain, the correlation between the severity of color vision and VA loss can imply the possible etiology of the visual loss. Copyright 2010 Elsevier Inc. All rights reserved.

Long-term effect of surface light scattering and glistenings of intraocular lenses on visual function.

PubMed

Hayashi, Ken; Hirata, Akira; Yoshida, Motoaki; Yoshimura, Koichi; Hayashi, Hideyuki

2012-08-01

To investigate the long-term effect of surface light scattering and glistenings of various intraocular lenses (IOLs) on visual function and optical aberrations after cataract surgery. Case-control study. Thirty-five eyes that underwent implantation of a hydrophobic acrylic, silicone, or polymethyl methacrylate (PMMA) IOL more than 10 years ago were recruited. The scattering light intensity of the surface and internal matrix of the optic was measured using Scheimpflug photography. Visual acuity (VA) was measured using VA charts, and contrast VA and that with glare (glare VA) were examined using a contrast sensitivity tester. Ocular higher-order aberrations (HOAs) were measured using a Hartmann-Shack aberrometer. Mean scattering light intensity of the surface and internal matrix of the optic was significantly higher in the acrylic group than in the silicone and PMMA groups (P < .0001). Mean uncorrected VA, photopic and mesopic contrast VA and glare VA, and HOAs did not differ significantly among groups, although mean corrected VA in the acrylic group was significantly better than that in the other groups (P = .0023). Scattering light intensity of the surface and internal matrix did not correlate with VA, contrast VA, or glare VA, and did not correlate with ocular and internal optic HOAs in the acrylic group. At more than 10 years postoperatively, visual function, including contrast sensitivity, and ocular HOAs were comparable among eyes that received acrylic, silicone, and PMMA IOLs. Surface scattering and glistenings with the acrylic IOLs were not significantly correlated with visual function and optical aberrations. Copyright © 2012 Elsevier Inc. All rights reserved.

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

PubMed

Kaido, Minako; Toda, Ikuko; Oobayashi, Tomoo; Kawashima, Motoko; Katada, Yusaku; Tsubota, Kazuo

2016-01-01

To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23-43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20-49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05). Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity

PubMed Central

Kaido, Minako

2016-01-01

Purpose To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Methods Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23–43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20–49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. Results The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05), Conclusions Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE. PMID:27045760

Predictors of visual outcome in patients operated for craniopharyngioma - a Danish national study.

PubMed

Jacobsen, Mads Forslund; Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Doroudian, Ghazaleh; Nissen, Kamilla Rothe; Fugleholm, Kåre; Poulsgaard, Lars; Siersma, Volkert; Heegaard, Steffen

2018-02-01

Craniopharyngioma often causes visual loss due to the close relation to the anterior visual pathways. This study investigates the incidence and predictors of visual outcomes in patients with craniopharyngioma. Data from sixty-six patients who underwent surgery for craniopharyngioma from 2009 to 2013 in Denmark were reviewed. Primary outcomes were visual acuity (VA) and visual field (VF) defects from pre-and postoperative visits. Secondary outcomes were optic nerve atrophy (OA) and papilledema. Fifty-eight patients were included. The VA of the patients 1-year after surgery improved by -0.16 log(MAR) (95%CI: -0.30 to -0.02; p = 0.0266). Visual field (VF) defects worsened in 17 eyes (30%), remained stable in 21 eyes (37%) and improved in 19 eyes (33%). The presence of papilledema and the absence of OA were significantly correlated with an improvement in VA postoperatively (p = 0.011 and p = 0.011, respectively). Patients undergoing surgery within a week or less after their first ophthalmological examination had a significant improvement in VA (-0.36; 95%CI: -0.62 to -0.09; p = 0.0099). Patients undergoing surgery using a subfrontal approach also showed improvement in VA (p = 0.048). Tumour recurrence had a significantly worse VA outcome (p = 0.0074). Patients show a slight improvement in VA 1-year after operation for craniopharyngioma. The presence of papilledema and early surgical intervention is associated with a significant improvement in VA. Early involvement of a dedicated ophthalmologist is recommended to secure an early detection of a visual decline and potential tumour recurrence. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Ophthalmic Manifestations and Causes of Vision Impairment in Ebola Virus Disease Survivors in Monrovia, Liberia.

PubMed

Shantha, Jessica G; Crozier, Ian; Hayek, Brent R; Bruce, Beau B; Gargu, Catherine; Brown, Jerry; Fankhauser, John; Yeh, Steven

2017-02-01

To describe the ocular findings, visual impairment, and association of structural complications of uveitis with visual impairment in a cohort of survivors of Ebola virus disease (EVD) in Monrovia, Liberia. Retrospective, uncontrolled, cross-sectional study. Survivors of EVD who were evaluated in an ophthalmology clinic at Eternal Love Winning Africa (ELWA) Hospital in Monrovia, Liberia. A cohort of EVD survivors who underwent baseline ophthalmic evaluation at ELWA Hospital were retrospectively reviewed for demographic information, length of Ebola treatment unit (ETU) stay, visual acuity (VA), and ophthalmic examination findings. For patients with uveitis, disease activity (active vs. inactive) and grade of inflammation were recorded according to Standardization of Uveitis Nomenclature criteria. The level of VA impairment was categorized according to World Health Organization classification for VA impairment as follows: normal/mild, VA 20/70 or better; moderate, VA 20/70-20/200; severe, VA 20/200-20/400; blindness, VA <20/400. Visual acuity, length of ETU stay, and structural complications were compared between EVD survivors with and without uveitis. Structural complications associated with moderate VA impairment or poorer were analyzed. Frequency of ocular complications including uveitis and optic neuropathy in EVD survivors, level of VA impairment in EVD survivors with uveitis, and structural complications associated with VA impairment in EVD survivors. A total of 96 survivors of EVD were examined. A total of 21 patients developed an EVD-associated uveitis, and 3 patients developed an EVD-associated optic neuropathy. Visual acuity was blind (VA >20/400) in 38.5% of eyes with uveitis. Anatomic subtypes of uveitis included anterior, posterior, and panuveitis in 2, 13, and 6 patients, respectively. Examination findings associated with at least moderate visual impairment by World Health Organization criteria (VA <20/70) included keratic precipitates (P < 0.002), posterior synechiae (P < 0.002), vitritis (P < 0.005), and chorioretinal scars (P < 0.02). Survivors of EVD are at risk for uveitis, which may lead to secondary structural complications, visual impairment, and blindness. Eye care resources should be mobilized for EVD survivors in West Africa because of the frequency of this spectrum of disease complication and its potential for severe VA impairment and blindness. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

All-distance visual acuity and contrast visual acuity in eyes with a refractive multifocal intraocular lens with minimal added power.

PubMed

Hayashi, Ken; Yoshida, Motoaki; Hayashi, Hideyuki

2009-03-01

To compare visual acuity (VA) from far to near distances, photopic and mesopic contrast VA, and contrast VA in the presence of a glare source (glare VA), between eyes with a new refractive multifocal intraocular lens (IOL) with added power of only +3.0 diopters and those with a monofocal IOL. Comparative, nonrandomized, interventional study. Forty-four eyes of 22 patients who were scheduled for implantation of a refractive multifocal IOL (Hoya SFX MV1; Tokyo, Japan) and 44 eyes of 22 patients scheduled for implantation of a monofocal IOL. All patients underwent phacoemulsification with bilateral implantation of either multifocal or monofocal IOLs. At approximately 3 months after surgery, monocular and binocular VA from far to near distances was measured using the all-distance vision tester (Kowa AS-15; Tokyo, Japan), whereas photopic and mesopic contrast VA and glare VA were examined using the Contrast Sensitivity Accurate Tester (Menicon CAT-2000, Nagoya, Japan). Pupillary diameter and the degree of IOL decentration and tilt were correlated with VA at all distances. Mean VA in both the multifocal and monofocal IOL groups decreased gradually from far to near distances. When comparing the 2 groups, however, both uncorrected and best distance-corrected intermediate VA at 0.5 m and near VA at 0.3 m in the multifocal IOL group were significantly better than those in the monofocal IOL group (P

An ERP study on whether semantic integration exists in processing ecologically unrelated audio-visual information.

PubMed

Liu, Baolin; Meng, Xianyao; Wang, Zhongning; Wu, Guangning

2011-11-14

In the present study, we used event-related potentials (ERPs) to examine whether semantic integration occurs for ecologically unrelated audio-visual information. Videos with synchronous audio-visual information were used as stimuli, where the auditory stimuli were sine wave sounds with different sound levels, and the visual stimuli were simple geometric figures with different areas. In the experiment, participants were shown an initial display containing a single shape (drawn from a set of 6 shapes) with a fixed size (14cm(2)) simultaneously with a 3500Hz tone of a fixed intensity (80dB). Following a short delay, another shape/tone pair was presented and the relationship between the size of the shape and the intensity of the tone varied across trials: in the V+A- condition, a large shape was paired with a soft tone; in the V+A+ condition, a large shape was paired with a loud tone, and so forth. The ERPs results revealed that N400 effect was elicited under the VA- condition (V+A- and V-A+) as compared to the VA+ condition (V+A+ and V-A-). It was shown that semantic integration would occur when simultaneous, ecologically unrelated auditory and visual stimuli enter the human brain. We considered that this semantic integration was based on semantic constraint of audio-visual information, which might come from the long-term learned association stored in the human brain and short-term experience of incoming information. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

VA Health Professional Scholarship and Visual Impairment and Orientation and Mobility Professional Scholarship Programs. Final rule.

PubMed

2013-08-20

The Department of Veterans Affairs (VA) is amending its VA Health Professional Scholarship Program (HPSP) regulations. VA is also establishing regulations for a new program, the Visual Impairment and Orientation and Mobility Professional Scholarship Program (VIOMPSP). These regulations comply with and implement sections 302 and 603 of the Caregivers and Veterans Omnibus Health Services Act of 2010 (the 2010 Act). Section 302 of the 2010 Act established the VIOMPSP, which authorizes VA to provide financial assistance to certain students seeking a degree in visual impairment or orientation or mobility, in order to increase the supply of qualified blind rehabilitation specialists for VA and the United States. Section 603 of the 2010 Act reauthorized and modified HPSP, a program that provides scholarships for education or training in certain health care occupations.

Influences of selective adaptation on perception of audiovisual speech

PubMed Central

Dias, James W.; Cook, Theresa C.; Rosenblum, Lawrence D.

2016-01-01

Research suggests that selective adaptation in speech is a low-level process dependent on sensory-specific information shared between the adaptor and test-stimuli. However, previous research has only examined how adaptors shift perception of unimodal test stimuli, either auditory or visual. In the current series of experiments, we investigated whether adaptation to cross-sensory phonetic information can influence perception of integrated audio-visual phonetic information. We examined how selective adaptation to audio and visual adaptors shift perception of speech along an audiovisual test continuum. This test-continuum consisted of nine audio-/ba/-visual-/va/ stimuli, ranging in visual clarity of the mouth. When the mouth was clearly visible, perceivers “heard” the audio-visual stimulus as an integrated “va” percept 93.7% of the time (e.g., McGurk & MacDonald, 1976). As visibility of the mouth became less clear across the nine-item continuum, the audio-visual “va” percept weakened, resulting in a continuum ranging in audio-visual percepts from /va/ to /ba/. Perception of the test-stimuli was tested before and after adaptation. Changes in audiovisual speech perception were observed following adaptation to visual-/va/ and audiovisual-/va/, but not following adaptation to auditory-/va/, auditory-/ba/, or visual-/ba/. Adaptation modulates perception of integrated audio-visual speech by modulating the processing of sensory-specific information. The results suggest that auditory and visual speech information are not completely integrated at the level of selective adaptation. PMID:27041781

Functional and visual acuity outcomes of cataract surgery in Timor-Leste (East Timor).

PubMed

Naidu, Girish; Correia, Marcelino; Nirmalan, Praveen; Verma, Nitin; Thomas, Ravi

2014-12-01

To report functional outcomes following cataract surgery in Timor-Leste. Pre- and post-intervention study measuring visual function improvement following cataract surgery. Presenting visual acuity (VA) was measured and visual function documented using the Indian vision function questionnaire (IND-VFQ). All 174 persons undergoing cataract surgery from November 2009 to January 2011 in Timor-Leste were included. Mean age was 65.4 years; 113 (64.9%) were male, 143 (82.1%) were from a rural background and 151 (86.8%) were illiterate. Pre-operatively, 77 of 174 patients (44.3%, 95% confidence interval, CI, 37.0-51.7%) were blind (VA ≤3/60), 77 (44.3%, 95% CI 37.0-51.7%) were visually impaired (VA <6/18->3/60), while 20 (11.5%, 95% CI 7.4-16.9%) had presenting acuity ≥6/18 in the better eye. Following surgery, significant improvement in visual function was demonstrated by an effect size of 2.8, 3.7 and 3.9 in the domains of general functioning, psychosocial impact and visual symptoms, respectively. Four weeks following surgery, 85 patients (48.9%, 95% CI 41.5-66.3%) had a presenting VA ≥6/18, 74 (42.5%, 95% CI 35.3-45.9%) were visually impaired and 15 (8.6%, 95% CI 5.0-13.6%) were blind. IND-VFQ improvement occurred even in patients remaining visually impaired or blind following surgery. In this setting, cataract surgery led to a significant improvement in visual function but the VA results did not meet World Health Organization quality criteria. IND-VFQ results, although complementary to clinical VA outcomes did not, in isolation, reflect the need to improve program quality.

Gains following perceptual learning are closely linked to the initial visual acuity.

PubMed

Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

2016-04-28

The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA.

A graph algebra for scalable visual analytics.

PubMed

Shaverdian, Anna A; Zhou, Hao; Michailidis, George; Jagadish, Hosagrahar V

2012-01-01

Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data.

COMPARISON OF VISUAL PROGNOSIS AND CLINICAL FEATURES OF CYTOMEGALOVIRUS RETINITIS IN HIV AND NON-HIV PATIENTS.

PubMed

Kim, Dong Yoon; Jo, Jaehyuck; Joe, Soo Geun; Kim, June-Gone; Yoon, Young Hee; Lee, Joo Yong

2017-02-01

To compare the visual prognosis and clinical features of cytomegalovirus (CMV) retinitis between HIV and non-HIV patients. Retrospective cross-sectional study on patients diagnosed with CMV retinitis. Depending on the presence of HIV infection, best-corrected visual acuity (VA) and clinical feature of CMV retinitis were analyzed. The clinical characteristics associated with poor visual prognosis after antiviral treatment were also identified. A total of 78 eyes (58 patients) with CMV retinitis were included in this study: 21 eyes and 57 eyes in HIV and non-HIV patients, respectively. Best-corrected VA was not significantly different between HIV and non-HIV patients. The rate of foveal involvement, retinal detachment, involved zone, and mortality did not significantly differ between the two groups. Visual acuity after antiviral treatment was significantly worse (pretreatment logarithm of the minimal angle of resolution best-corrected VA, 0.54 ± 0.67 [Snellen VA, 20/63]; posttreatment logarithm of the minimal angle of resolution best-corrected VA, 0.77 ± 0.94 [Snellen VA, 20/125]; P = 0.014). Poor visual prognosis was significantly associated with Zone 1 involvement, retinal detachment, and a poor general condition. The overall visual prognosis and the clinical features of CMV retinitis do not differ between HIV and non-HIV patients. The visual prognosis of CMV retinitis still remains quite poor despite advancements in antiviral treatment. This poor prognosis after antiviral treatment is associated with retinal detachment during follow-up, Zone 1 involvement, and the poor general condition of the patient.

Longitudinal Changes in Visual Acuity and Health Related Quality of Life. The Los Angeles Latino Eye Study

PubMed Central

McKean-Cowdin, Roberta; Varma, Rohit; Hays, Ron D.; Wu, Joanne; Choudhury, Farzana; Azen, Stanley P.

2010-01-01

Purpose To examine the association between longitudinal changes in visual acuity (VA) and Health Related Quality of Life (HRQOL) in a population-based sample of adult Latinos. Design A population-based cohort study of eye disease in Latinos. Participants 3,169 adult Latino participants who live in the city of La Puente, California. Methods Data for these analyses were collected for the Los Angeles Latino Eye Study (LALES). Distance visual acuity (VA) was measured during a detailed ophthalmologic examination using the standard Early Treatment Diabetic Retinopathy Study protocol at baseline and a 4 year follow-up examination. HRQOL was assessed by the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and the Medical Outcomes Study 12-Item Short-Form Health Survey version 1 (SF-12 v.1). Main Outcome Measures Mean differences in HRQOL composite and subscale scores between baseline and follow-up were calculated for 3,169 participants with complete clinical examination and HRQOL data at both time points. Mean differences and effect sizes (ES) for NEI-VFQ and SF-12 v.1 scores were calculated for 3 categories of VA change over the 4 year follow-up period (VA improved ≥ 2 lines, no change in VA or −2

37 CFR 202.3 - Registration of copyright.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Class VA: Works of the visual arts. This class includes all published and unpublished pictorial, graphic... recordings), or VA (works of the visual arts, including architectural works). Copies of the generic... published photographs after consultation and with the permission and under the direction of the Visual Arts...

The Effect of Gaze Angle on Visual Acuity in Infantile Nystagmus.

PubMed

Dunn, Matt J; Wiggins, Debbie; Woodhouse, J Margaret; Margrain, Tom H; Harris, Christopher M; Erichsen, Jonathan T

2017-01-01

Most individuals with infantile nystagmus (IN) have an idiosyncratic gaze angle at which their nystagmus intensity is minimized. Some adopt an abnormal head posture to use this "null zone," and it has therefore long been assumed that this provides people with nystagmus with improved visual acuity (VA). However, recent studies suggest that improving the nystagmus waveform could have little, if any, influence on VA; that is, VA is fundamentally limited in IN. Here, we examined the impact of the null zone on VA. Visual acuity was measured in eight adults with IN using a psychophysical staircase procedure with reversals at three horizontal gaze angles, including the null zone. As expected, changes in gaze angle affected nystagmus amplitude, frequency, foveation duration, and variability of intercycle foveation position. Across participants, each parameter (except frequency) was significantly correlated with VA. Within any given individual, there was a small but significant improvement in VA (0.08 logMAR) at the null zone as compared with the other gaze angles tested. Despite this, no change in any of the nystagmus waveform parameters was significantly associated with changes in VA within individuals. A strong relationship between VA and nystagmus characteristics exists between individuals with IN. Although significant, the improvement in VA observed within individuals at the null zone is much smaller than might be expected from the occasionally large variations in intensity and foveation dynamics (and anecdotal patient reports of improved vision), suggesting that improvement of other aspects of visual performance may also encourage use of the null zone.

Three-dimensional Imaging of High-resolution Computer Tomography of Singers' Larynges-A Pilot Study.

PubMed

Vorik, Alexandra; Unteregger, Fabian; Zwicky, Salome; Schiwowa, Julia; Potthast, Silke; Storck, Claudio

2017-01-01

Biplanar imaging technique is not sufficient for an exact visualization and evaluation of the laryngeal biomechanics during speaking or singing. The aim of this pilot study was to test a 3D-visualization software MIMICS (Materialize Interactive Medical Image Control System, Materialize, Leuven, Belgium) for visualizing laryngeal cartilages and resonance space of living humans during singing based on high-resolution computed tomography (HRCT) and analyzing the biomechanics thereof. This is a prospective pilot study. A total of 10 professional female singers (five sopranos and five altos) was scanned with HRCT in three singing positions fundamental frequency (ƒo), first octave (ƒo+1 8va) and second octave (ƒo+2 8va). All relevant laryngeal structures and resonance space could be 3D visualized. Superimposing the different HRCT scans showed an inward rotation and rocking of the arytenoid cartilages from ƒo+1 8va to ƒo+2 8va and a backward tilting of the cricoid cartilage from ƒo+1 8va to ƒo+2 8va. Moreover, we could demonstrate a vocal fold elongation of 13% from ƒo to ƒo+1 8va and an additional elongation from ƒo+1 8va to ƒo+2 8va of 10% in type A cricothyroid joints (CTJ) A and 4% in CTJ's type B/C. There were no significant differences between sopranos and altos in all parameters (length of the glottis, subglottic diameter, distance between anterior commissure and cervical spine, and CTJ distribution). This noninvasive 3D-visualization technique with MIMICS allows the anatomical structures and landmarks of the larynx to be analyzed. We believe that this pilot study will serve as a basis for further biomechanical studies on speakers' and singers' larynges. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Ocular vascular occlusive disorders: Natural history of visual outcome☆

PubMed Central

Hayreh, Sohan Singh

2014-01-01

Ocular vascular occlusive disorders collectively constitute the most common cause of visual disability. Before a disease can be managed, it is essential to understand its natural history, so as to be able to assess the likely effectiveness of any intervention. I investigated natural history of visual outcome in prospective studies of 386 eyes with non-arteritic anterior ischemic optic neuropathy (NA-AION), 16 eyes with non-arteritic posterior ischemic optic neuropathy, 697 eyes with central retinal vein occlusion (CRVO), 67 eyes with hemi-CRVO (HCRVO), 216 eyes with branch retinal vein occlusion (BRVO), 260 eyes with central retinal artery occlusion (CRAO), 151 eyes with branch retinal artery occlusion (BRAO) and 61 eyes with cilioretinal artery occlusion (CLRAO). My studies have shown that every one of these disorders consists of multiple distinct clinical sub-categories with different visual findings. When an ocular vascular occlusive disorder is caused by giant cell arteritis, which is an ophthalmic emergency, it would be unethical to do a natural history study of visual outcome in them, because in this case early diagnosis and immediate, intensive high-dose steroid therapy is essential to prevent any further visual loss, not only in the involved eye but also in the fellow, normal eye. In NA-AION in eyes seen ≤2 weeks after the onset, visual acuity (VA) improved in 41% of those with VA 20/70 or worse, and visual field (VF) improved in 26% of those with moderate to severe VF defect. In non-ischemic CRVO eyes with VA 20/70 or worse, VA improved in 47% and in ischemic CRVO in 23%; moderate to severe VF defect improved in 79% in non-ischemic CRVO and in 27% in ischemic CRVO. In HCRVO, overall findings demonstrated that initial VA and VF defect and the final visual outcome were different in non-ischemic from ischemic HCRVO – much better in the former than the latter. In major BRVO, in eyes with initial VA of 20/70 or worse, VA improved in 69%, and moderate to severe VF defect improved in 52%. In macular BRVO with 20/70 or worse initial VA, it improved in 53%, and initial minimal-mild VF defect was stable or improved in 85%. In various types of CRAO there are significant differences in both initial and final VA and VF defects. In CRAO eyes seen within 7 days of onset and initial VA of counting fingers or worse, VA improved in 82% with transient non-arteritic CRAO, 67% with non-arteritic CRAO with cilioretinal artery sparing, 22% with non-arteritic CRAO. Central VF improved in 39% of transient non-arteritic CRAO, 25% of non-arteritic CRAO with cilioretinal artery sparing and 21% of non-arteritic CRAO. Peripheral VF improved in non-arteritic CRAO in 39% and in transient non-arteritic CRAO in 39%. In transient CRAO, finally peripheral VFs were normal in 93%. In non-arteritic CRAO eyes initially 22% had normal peripheral VF and in the rest it improved in 39%. Final VA of 20/40 or better was seen in 89% of permanent BRAO, and in 100% of transient BRAO and non-arteritic CLRAO. In permanent BRAO eyes, among those seen within 7 days of onset, central VF defect improved in 47% and peripheral VF in 52%, and in transient BRAO central and peripheral VFs were normal at follow-up. My studies showed that AION, CRVO, BRVO, CRAO and BRAO, each consist of multiple distinct clinical sub-categories with different visual outcome. Contrary to the prevalent impression, these studies on the natural history of visual outcome have shown that there is a statistically significant spontaneous visual improvement in each category. The factors which influence the visual outcome in various ocular vascular occlusive disorders are discussed. PMID:24769221

SOCRAT Platform Design: A Web Architecture for Interactive Visual Analytics Applications

PubMed Central

Kalinin, Alexandr A.; Palanimalai, Selvam; Dinov, Ivo D.

2018-01-01

The modern web is a successful platform for large scale interactive web applications, including visualizations. However, there are no established design principles for building complex visual analytics (VA) web applications that could efficiently integrate visualizations with data management, computational transformation, hypothesis testing, and knowledge discovery. This imposes a time-consuming design and development process on many researchers and developers. To address these challenges, we consider the design requirements for the development of a module-based VA system architecture, adopting existing practices of large scale web application development. We present the preliminary design and implementation of an open-source platform for Statistics Online Computational Resource Analytical Toolbox (SOCRAT). This platform defines: (1) a specification for an architecture for building VA applications with multi-level modularity, and (2) methods for optimizing module interaction, re-usage, and extension. To demonstrate how this platform can be used to integrate a number of data management, interactive visualization, and analysis tools, we implement an example application for simple VA tasks including raw data input and representation, interactive visualization and analysis. PMID:29630069

SOCRAT Platform Design: A Web Architecture for Interactive Visual Analytics Applications.

PubMed

Kalinin, Alexandr A; Palanimalai, Selvam; Dinov, Ivo D

2017-04-01

The modern web is a successful platform for large scale interactive web applications, including visualizations. However, there are no established design principles for building complex visual analytics (VA) web applications that could efficiently integrate visualizations with data management, computational transformation, hypothesis testing, and knowledge discovery. This imposes a time-consuming design and development process on many researchers and developers. To address these challenges, we consider the design requirements for the development of a module-based VA system architecture, adopting existing practices of large scale web application development. We present the preliminary design and implementation of an open-source platform for Statistics Online Computational Resource Analytical Toolbox (SOCRAT). This platform defines: (1) a specification for an architecture for building VA applications with multi-level modularity, and (2) methods for optimizing module interaction, re-usage, and extension. To demonstrate how this platform can be used to integrate a number of data management, interactive visualization, and analysis tools, we implement an example application for simple VA tasks including raw data input and representation, interactive visualization and analysis.

Visual Acuity and Contrast Sensitivity Development in Children: Sweep Visually Evoked Potential and Psychophysics.

PubMed

Almoqbel, Fahad M; Irving, Elizabeth L; Leat, Susan J

2017-08-01

The purpose of this study was to investigate the development of visual acuity (VA) and contrast sensitivity in children as measured with objective (sweep visually evoked potential) and subjective, psychophysical techniques, including signal detection theory (SDT), which attempts to control for differences in criterion or behavior between adults and children. Furthermore, this study examines the possibility of applying SDT methods with children. Visual acuity and contrast thresholds were measured in 12 children 6 to 7 years old, 10 children 8 to 9 years old, 10 children 10 to 12 years old, and 16 adults. For sweep visually evoked potential measurements, spatial frequency was swept from 1 to 40 cpd to measure VA, and contrast of sine-wave gratings (1 or 8 cpd) was swept from 0.33 to 30% to measure contrast thresholds. For psychophysical measurements, VA and contrast thresholds (1 or 8 cpd) were measured using a temporal two-alternative forced-choice staircase procedure and also with a yes-no SDT procedure. Optotype (logMAR [log of the minimum angle of resolution]) VA was also measured. The results of the various procedures were in agreement showing that there are age-related changes in threshold values and logMAR VA after the age of 6 years and that these visual functions do not become adult-like until the age of 8 to 9 years at the earliest. It was also found that children can participate in SDT procedures and do show differences in criterion compared with adults in psychophysical testing. These findings confirm a slightly later development of VA and contrast sensitivity (8 years or older) and indicate the importance of using SDT or forced-choice procedures in any developmental study to attempt to overcome the effect of criterion in children.

Association between changes in visual acuity and vision-related quality of life in Japanese patients with low vision.

PubMed

Yanagisawa, Mieko; Kato, Satoshi; Kunimatsu, Shiho; Kobayashi, Megumi; Ochiai, Makiko

2011-01-01

To investigate the association between vision-related quality of life (VRQOL) and changes in visual acuity (VA). We examined the VA in 100 patients for > 1 year and evaluated the degree of its impact on VRQOL using the National Eye Institute Visual Function (VF) Questionnaire (VFQ-25; Japanese version). Before determining VFQ-25, we monitored the changes in VA in these patients for 1 year and classified them into the following two groups depending on VA changes. Patients exhibiting a decline of > 3 steps in VA, as assessed by the logarithm of the minimum angle of resolution scale, were placed in the 'decline' group (47.0%) and patients exhibiting no change in VA were placed in the 'no change' group (53.0%). We compared the VFQ-25 scores between both groups in all patients with glaucoma (GLA) and macular degeneration (MD). The total score of the decline was 34.9 ± 13.6 and that of the no change group was 44.6 ± 13.9: the difference in the scores between both groups was statistically significant (p = 0.006). Similar results were obtained for patients with GLA and MD (p = 0.007 and 0.003, respectively). VRQOL differed between patients with constant VA and those with reduced VA, even though VA values were equal at a certain time point. Copyright © 2010 S. Karger AG, Basel.

Long-term Follow-up of Cytomegalovirus Retinitis in Non-HIV Immunocompromised Patients: Clinical Features and Visual Prognosis.

PubMed

Iu, Lawrence P; Fan, Michelle C; Lau, Jordy K; Chan, Thomas S; Kwong, Yok-Lam; Wong, Ian Y

2016-05-01

To evaluate clinical features and long-term visual outcome of cytomegalovirus (CMV) retinitis in patients without human immunodeficiency virus (HIV) infection, and to determine factors that predict visual outcome. Retrospective cohort study. Consecutive patients with CMV retinitis without HIV infection were reviewed. Main outcome measures included clinical features, proportion of eyes with 6-month and final visual acuity (VA) <20/70 and <20/400, and odds ratios of factors associated with poor visual outcome. A total of 20 eyes from 13 patients were included with a median follow-up time of 17 months. All had at least 6 months of follow-up except 1 patient who died from sepsis at 1 month. At presentation, 50% of eyes had VA <20/70 and 25% had VA <20/400. Zone 1 involvement occurred in 55% and vitreous haze ≥grade 2+ occurred in 25%. Recurrence occurred in 33.3% at a mean time of 6.4 ± 3.3 weeks after discontinuation of anti-CMV therapy. The retinal detachment rate was 21.7% per eye-year and mortality rate was 11.7% per person-year. At final visit, 60% had VA <20/70 and 35% had VA <20/400. Macular involvement was significantly associated with poor final VA <20/400 (odds ratio = 25.00, P = .016). CMV retinitis without HIV infection was often aggressive at presentation. Significant intraocular inflammation was not uncommon. The long-term visual outcome was poor, especially in those with macular involvement. Copyright © 2016 Elsevier Inc. All rights reserved.

A Locally Weighted Fixation Density-Based Metric for Assessing the Quality of Visual Saliency Predictions

NASA Astrophysics Data System (ADS)

Gide, Milind S.; Karam, Lina J.

2016-08-01

With the increased focus on visual attention (VA) in the last decade, a large number of computational visual saliency methods have been developed over the past few years. These models are traditionally evaluated by using performance evaluation metrics that quantify the match between predicted saliency and fixation data obtained from eye-tracking experiments on human observers. Though a considerable number of such metrics have been proposed in the literature, there are notable problems in them. In this work, we discuss shortcomings in existing metrics through illustrative examples and propose a new metric that uses local weights based on fixation density which overcomes these flaws. To compare the performance of our proposed metric at assessing the quality of saliency prediction with other existing metrics, we construct a ground-truth subjective database in which saliency maps obtained from 17 different VA models are evaluated by 16 human observers on a 5-point categorical scale in terms of their visual resemblance with corresponding ground-truth fixation density maps obtained from eye-tracking data. The metrics are evaluated by correlating metric scores with the human subjective ratings. The correlation results show that the proposed evaluation metric outperforms all other popular existing metrics. Additionally, the constructed database and corresponding subjective ratings provide an insight into which of the existing metrics and future metrics are better at estimating the quality of saliency prediction and can be used as a benchmark.

Do school classrooms meet the visual requirements of children and recommended vision standards?

PubMed

Negiloni, Kalpa; Ramani, Krishna Kumar; Sudhir, Rachapalle Reddi

2017-01-01

Visual demands of school children tend to vary with diverse classroom environments. The study aimed to evaluate the distance and near Visual Acuity (VA) demand in Indian school classrooms and their comparison with the recommended vision standards. The distance and near VA demands were assessed in 33 classrooms (grades 4 to 12) of eight schools. The VA threshold demand relied on the smallest size of distance and near visual task material and viewing distance. The logMAR equivalents of minimum VA demand at specific seating positions (desk) and among different grades were evaluated. The near threshold was converted into actual near VA demand by including the acuity reserve. The existing dimensions of chalkboard and classroom, gross area in a classroom per student and class size in all the measured classrooms were compared to the government recommended standards. In 33 classrooms assessed (35±10 students per room), the average distance and near logMAR VA threshold demand was 0.31±0.17 and 0.44±0.14 respectively. The mean distance VA demand (minimum) in front desk position was 0.56±0.18 logMAR. Increased distance threshold demand (logMAR range -0.06, 0.19) was noted in 7 classrooms (21%). The mean VA demand in grades 4 to 8 and grades 9 to 12 was 0.35±0.16 and 0.24±0.16 logMAR respectively and the difference was not statistically significant (p = 0.055). The distance from board to front desk was greater than the recommended standard of 2.2m in 27 classrooms (82%). The other measured parameters were noted to be different from the proposed standards in majority of the classrooms. The study suggests the inclusion of task demand assessment in school vision screening protocol to provide relevant guidance to school authorities. These findings can serve as evidence to accommodate children with mild to moderate visual impairment in the regular classrooms.

Brief Report: Vision in Children with Autism Spectrum Disorder: What Should Clinicians Expect?

ERIC Educational Resources Information Center

Anketell, Pamela M.; Saunders, Kathryn J.; Gallagher, Stephen M.; Bailey, Clare; Little, Julie-Anne

2015-01-01

Anomalous visual processing has been described in individuals with autism spectrum disorder (ASD) but relatively few studies have profiled visual acuity (VA) in this population. The present study describes presenting VA in children with ASD (n = 113) compared to typically developing controls (n = 206) and best corrected visual acuity (BCVA) in a…

Visual symptomatology and referral patterns for Operation Iraqi Freedom and Operation Enduring Freedom veterans with traumatic brain injury.

PubMed

Bulson, Ryan; Jun, Weon; Hayes, John

2012-01-01

Advances in protective armor technology and changes in the "patterns of war" have created a population of Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) veterans with traumatic brain injury (TBI) that provide a unique challenge to Department of Veterans Affairs (VA) healthcare practitioners. The purpose of the study was to determine the frequency of symptomatic ocular and visual sequelae of TBI in OIF/OEF veterans at the Portland VA Medical Center, a Polytrauma Support Clinic Team site. A retrospective analysis of 100 OIF/OEF veterans with TBI was conducted to determine the prevalence of ocular and visual complaints. Referral patterns were also investigated. Visual symptoms were reported in approximately 50% of veterans with TBI. Loss of consciousness, but not number of deployments or number of blast exposures, was found to have a statistically significant association with severity of reported visual symptoms. The most commonly reported symptoms included blurred vision (67%), photosensitivity (50%), and accommodative problems (40%). Visual symptoms of OIF/OEF veterans at the Portland VA Medical Center are reported at slightly lower rates than similar studies conducted at the Palo Alto and Edward Hines Jr VA facilities.

Visual impairment in adult people with moderate, severe, and profound intellectual disability.

PubMed

Warburg, M

2001-10-01

To assess visual impairment in adults with intellectual disability after de-institutionalisation. The county has a population of 385 483 persons of 18 years and older; 961 were moderately, severely or profoundly intellectually impaired (ID), 837 of them (87 %) participated in the investigation. Visual acuity, VA: Østerberg picture charts and reduced copies for near vision could be used in 71% of the patients. Teller preferential looking procedure was applied to people who were unable to cooperate with the picture charts. When examined with picture wall chart VA 0.3-> or =0.10) was found in 10.8%, severe low vision in 1.2% (VA <0.10-> or =0.05), and blindness (VA<0.05) in 3.8%. Poor near vision (<0.3) was present in 19%. Those assessed with Teller acuity cards had poorer vision than the others. It is possible that the low values of assessment with Teller cards represent a combination of gnostic and resolution deficiencies, which means that the results of grating VA and recognition VA are non-comparable. Ophthalmic disorders: The most widespread medical condition was cerebral visual impairment, the most frequent eye disorders were optic atrophy, high myopia, cataract, and keratoconus. Refraction: Refraction was assessed in 710 persons (85%), the most prevalent cause of visual impairment was uncorrected ametropia. Hypermetropia of >+1.50 was found in 151 of 710 subjects (21%), and spectacles were used by 106 (15%); myopia <-1.0 was present in 213 individuals (30%), 95 persons (13%) had lenses <-1.0. Resettled adult people with intellectual disability have a high prevalence of treatable visual impairment. A structured scheme of referral to optometric and ophthalmological care is essential if these people are to be given the care to which they are entitled.

A survey of visual impairment and blindness in children attending seven schools for the blind in Myanmar.

PubMed

Muecke, James; Hammerton, Michael; Aung, Yee Yee; Warrier, Sunil; Kong, Aimee; Morse, Anna; Holmes, Martin; Yapp, Michael; Hamilton, Carolyn; Selva, Dinesh

2009-01-01

To determine the causes of visual impairment and blindness amongst children in schools for the blind in Myanmar; to identify the avoidable causes of visual impairment and blindness; and to provide spectacles, low vision aids, orientation and mobility training and ophthalmic treatment where indicated. Two hundred and eight children under 16 years of age from all 7 schools for the blind in Myanmar were examined and the data entered into the World Health Organization Prevention of Blindness Examination Record for Childhood Blindness (WHO/PBL ERCB). One hundred and ninety nine children (95.7%) were blind (BL = Visual Acuity [VA] < 3/60 in the better eye) and 3 had severe visual impairment (SVI = VA < 6/60 to 3/60 in the better eye). Most children had corneal abnormalities as the major anatomical site of SVI/BL (100, 49.5%), however the cause of SVI/BL was unknown in the majority (88, 43.6%). Measles keratitis was the commonest identifiable cause (17.4%) and 88 children had avoidable causes of SVI/BL (43.6%). Nearly 16% of children required an optical device and 24.2% required medical attention, with a potential for visual improvement through intervention in 15.8%. Nearly half of the children in schools for the blind in Myanmar had potentially avoidable causes of SVI/BL. With measles being both the commonest identifiable and commonest avoidable cause, the data supports the need for a measles immunization campaign. There is also a need for a dedicated pediatric eye care center with regular ophthalmology visits to the schools, and improved optometric, low vision and orientation and mobility services in Myanmar.

Cognitive Foundations for Visual Analytics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greitzer, Frank L.; Noonan, Christine F.; Franklin, Lyndsey

In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions.

Visual outcome in Japanese patients with Acanthamoeba keratitis.

PubMed

Yamazoe, K; Yamamoto, Y; Shimazaki-Den, S; Shimazaki, J

2012-04-01

To identify prognostic factors affecting visual outcome in Acanthamoeba keratitis (AK) treated with topical chlorhexidine gluconate (CHG). A total of 35 eyes in 34 patients with AK were treated with 0.02% topical CHG. Patients were divided into two groups according to the final visual outcome: Group 1, final visual acuity (VA) of 20/25 or greater (22 eyes); Group 2, less than 20/25 (13 eyes). We compared these groups and evaluated the effectiveness of topical CHG compared with outcomes in previous reports. Ring infiltrate was observed more often in Group 2 (4.5% vs 61.5%, OR 33.6, 95% confidence interval (CI) 3.4-333.9, P<0.01). The duration between onset and diagnosis of AK was significantly longer (24.9 days vs 48.4 days, OR 1.03, 95% CI 1.00-1.06, P = 0.04) and VA at initial examination (log MAR) significantly lower (0.47 vs 1.59, OR 25.5, 95% CI 3.4-186.7, P<0.01) in Group 2 (visual outcome <20/25). Multivariate analysis revealed that only VA at initial examination was independently associated with worse visual outcome (adjusted OR 24.5, 95% CI 1.9-312.6, P=0.01). Seventeen (85.0%) of the 20 eyes diagnosed within 1 month and 24 (82.8%) of 29 eyes diagnosed within 2 months achieved a VA of 20/40 or greater. VA at initial examination was the most predictive factors for final visual outcome in AK. Topical CHG was comparably effective to other treatments, including polyhexamethyl biguanide and propamidine isethionate.

Five-Year Incidence of Visual Impairment in Middle-Aged Iranians: The Shahroud Eye Cohort Study.

PubMed

Hashemi, Hassan; Mehravaran, Shiva; Emamian, Mohammad Hassan; Fotouhi, Akbar

2017-02-01

To study the 5-year incidence of visual impairment and its causes and risk factors, in the middle-aged Iranian sample of the Shahroud Eye Cohort Study (ShECS). Data from subjects who had participated in both phases of the ShECS were used to determine age- and sex-specific incidence rates of visual impairment using the World Health Organization (WHO) definitions for bilateral low vision (visual acuity, VA, >0.5 and ≤1.3 LogMAR in the better eye) and blindness (VA worse than 1.3 LogMAR in the better eye). Risk ratios (RR) and 95% confidence intervals (CIs) were calculated using multivariable log-binomial regression. Of the 5079 ShECS I survivors, 4737 (93.3%) completed the 5-year follow-up. Their mean age at baseline was 50.9 ± 6.2 years, and 58.9% were female. The incidence of visual impairment was 1.12% (95% CI 0.82-1.42%) by presenting VA and 0.19% (95% CI 0.07-0.32%) by best-corrected VA; leading causes of the former were uncorrected refractive error (81.3%) and diabetic retinopathy (15.1%). In the multivariable model, risk factors for incident visual impairment by presenting VA were older age (RR 1.05, p = 0.044), lower education (RR 0.89, p = 0.002), and diabetes (RR 3.74, p < 0.001). This is the first incidence study of visual impairment in a middle-aged Iranian population. Since age is a major risk factor, the number of visually impaired is expected to increase as the population ages, and less treatable causes such as diabetic retinopathy begin to surface. Measures for tackling uncorrected refractive error and enhancing diabetes screening and preventive programs are recommended.

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice.

PubMed

Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

2018-01-01

For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162-P182] SC-raised mice. This was indeed the case: 40-50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice.

Night-shift work and risk of compromised visual acuity among the workers in an electronics manufacturing company.

PubMed

Lin, Yu-Cheng; Ho, Kuo-Jung

2018-01-01

To evaluate the association between night-shift work exposure and visual health, this cross-sectional study utilized visual acuity, a surrogate measure for visual function, as a parameter, and performed an analysis comparing visual acuity between daytime and nighttime employees in an electronics manufacturing company. Data of personal histories, occupational records, physical examinations and blood tests was obtained from the electronic health records of workers. The total of 8280 workers including 3098 women and 5182 men, wearing their own daily used eyeglasses, were included in the final analysis. The mean age of the sample population was 34.7 years old (standard deviation = 5.4 years). All workers were divided into 3 work categories - consistent daytime worker (CDW), day-shift worker (DSW) and night-shift worker (NSW). The check-up results of glasses-corrected visual acuity (c-VA) were utilized to classify individuals as good (≥ 1.2, both eyes) and inadequate (< 0.8, the better eye) c-VA. Consistent daytime workers had the highest rate of good c-VA (42.5% vs. 25.1% DSW and 21.1% NSW, p = 0.047). Night-shift workers had the highest rate of inadequate c-VA (CDW, DSW and NSW: 2.6%, 6.2%, and 7.6%, p = 0.03) among all employees. After controlling for covariates, NSW were found at an increased risk for inadequate c-VA (adjusted odds ratio (ORa) = 2.7, 95% confidence interval (CI): 2.0-3.6, vs. CDW), and less likely to have good c-VA (ORa = 0.4, 95% CI: 0.4-0.5, vs. CDW). Night-shift work is moderately associated with compromised visual acuity of employees in this electronics manufacturing company. Int J Occup Med Environ Health 2018;31(1):71-79. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Visual, Musculoskeletal, and Balance Complaints in AMD: A Follow-Up Study

PubMed Central

Richter, Hans Olof

2016-01-01

Purpose. To investigate whether patients with age-related macular degeneration (AMD) run a potentially higher risk of developing visual, musculoskeletal, and balance complaints than age-matched controls with normal vision. Methods. Visual assessments, self-rated visual function, self-rated visual, musculoskeletal, and balance complaints, and perceived general health were obtained in 37 AMD patients and 18 controls, at baseline and after an average of 3.8 years later. Results. At follow-up both groups reported decreased visual acuity (VA) and visual function, but only AMD patients reported significantly increased visual, musculoskeletal, and balance complaints. Decreased VA, need for larger font size when reading, need for larger magnification, and decreased self-rated visual function were identified as risk markers for increased complaints in AMD patients. These complaints were also identified as risk markers for decreased health. For controls, decreased VA and self-reported visual function were associated with increased visual and balance complaints. Conclusions. Visual deterioration was a risk marker for increased visual, musculoskeletal, balance, and health complaints in AMD patients. Specifically, magnifying visual aids, such as CCTV, were a risk marker for increased complaints in AMD patients. This calls for early and coordinated actions to treat and prevent visual, musculoskeletal, balance, and health complaints in AMD patients. PMID:27830084

Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

PubMed

Koefoed, Vilhelm F; Assmuss, Jörg; Høvding, Gunnar

2018-03-25

To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. The object detection distance was significantly correlated to the level of environmental light (p < 0.001), but not to the VA or ICS recorded in the test subjects. Female cadets had a significantly shorter target identification range than the male cadets. Neither CS nor VA were found to be significantly correlated to observation task performance. This apparent absence of proven predictive value of visual parameters for observation tasks in a maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Prevalence and Causes of Visual Impairment and Blindness among Cocoa Farmers in Ghana.

PubMed

Boadi-Kusi, Samuel Bert; Hansraj, Rekha; Mashige, Khathutshelo Percy; Osafo-Kwaako, Alfred; Ilechie, Alex Azuka; Abokyi, Samuel

2017-02-01

To determine the prevalence and causes of visual impairment and blindness among cocoa farmers in Ghana in order to formulate early intervention strategies. A cross-sectional study using multistage random sampling from four cocoa growing districts in Ghana was conducted from November 2013 to April 2014. A total of 512 cocoa farmers aged 40 years and older were interviewed and examined. The brief interview questionnaire was administered to elicit information on the demographics and socioeconomic details of participants. The examination included assessment of visual acuity (VA), retinoscopy, subjective refraction, direct ophthalmoscopy, slit-lamp biomicroscopy and intraocular pressure (IOP). For quality assurance, a random sample of cocoa farmers were selected and re-examined independently. Moderate to severe visual impairment (VA <6/18 to 3/60 in the better-seeing eye) was present in 89 participants (17.4%) and 27 (5.3%) were blind (presenting VA <3/60 in the better eye) defined using presenting VA. The main causes of visual impairment were cataract (45, 38.8%), uncorrected refractive error (42, 36.2%), posterior segment disorders (15, 12.9%), and corneal opacity (11, 9.5%). The prevalence of visual impairment and blindness among cocoa farmers in Ghana is relatively high. The major causes of visual impairment and blindness are largely preventable or treatable, indicating the need for early eye care service interventions.

Poorer Visual Acuity Is Associated with Declines in Cognitive Performance Across Multiple Cognitive Domains: The Maine-Syracuse Longitudinal Study.

PubMed

Dearborn, Peter J; Elias, Merrill F; Sullivan, Kevin J; Sullivan, Cara E; Robbins, Michael A

2018-06-21

Prior studies have found associations between visual acuity (VA) and cognitive function. However, these studies used a limited range of cognitive measures and did not control for cardiovascular disease risk factors (CVD-RFs) and baseline function. The primary objective of this study was to analyze the associations of VA and cognitive performance using a thorough neuropsychological test battery. This study used community-dwelling sample data across the sixth (2001-2006) and seventh (2006-2010) waves of the Maine-Syracuse Longitudinal Study (n=655). Wave 6 VA as measured by the Snellen Eye Test was the primary predictor of wave 6 and wave 7 Global cognitive performance, Visual-Spatial Organization and Memory, Verbal Episodic Memory, Working Memory, Scanning and Tracking, and Executive Function. Additionally, VA was used to predict longitudinal changes in wave 7 cognitive performance (wave 6 performance adjusted). We analyzed these relationships with multiple linear and logistic regression models adjusted for age, sex, education, ethnicity, depressive symptoms, physical function deficits in addition to CVD-RFs, chronic kidney disease, homocysteine, continuous systolic blood pressure, and hypertension status. Adjusted for demographic covariates and CVD-RFs, poorer VA was associated with concurrent and approximate 5-year declines in Global cognitive function, Visual-Spatial Organization and Memory, and Verbal Episodic Memory. VA may be used in combination with other screening measures to determine risk for cognitive decline. (JINS, 2018, 24, 1-9).

Rapid assessment of visual impairment (RAVI) in marine fishing communities in South India - study protocol and main findings

PubMed Central

2011-01-01

Background Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI) project. Methods A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA) was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was < 6/12 in either eye. Near vision was assessed using N notation chart binocularly. Visual impairment was defined as presenting VA < 6/18 in the better eye. Presbyopia is defined as binocular near vision worse than N8 in subjects with binocular distance VA of 6/18 or better. Results The data collection was completed in <12 weeks using two teams each consisting of one paramedical ophthalmic personnel and two community eye health workers. The prevalence of visual impairment was 30% (95% CI, 27.6-32.2). This included 111 (7.1%; 95% CI, 5.8-8.4) individuals with blindness. Cataract was the leading cause of visual impairment followed by uncorrected refractive errors. The prevalence of blindness according to WHO definition (presenting VA < 3/60 in the better eye) was 2.7% (95% CI, 1.9-3.5). Conclusion There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI) reported in this paper is robust, quick and has the potential to be replicated in other areas. PMID:21929802

Prevalence of Visual Impairment and Refractive Errors in Children of South Sinai, Egypt.

PubMed

Yamamah, Gamal Abdel Naser; Talaat Abdel Alim, Ahmed Ahmed; Mostafa, Yehia Salah El Din; Ahmed, Rania Ahmed Abdel Salam; Mohammed, Asmaa Mahmoud; Mahmoud, Asmaa Mohammed

2015-01-01

To assess the prevalence and causes of visual impairment in children of South Sinai, and to evaluate outcomes of rehabilitation programs. Population-based, cross-sectional analysis of 2070 healthy school children screened for visual impairment from 2009 through 2010 in cities of South Sinai and their surrounding Bedouin settlements. Visual acuity (VA) was tested using Snellen charts followed by cycloplegic autorefractometry for cases with presenting VA ≤ 6/9. Appropriate eyeglasses were prescribed and VA re-evaluated. This study included 1047 boys and 1023 girls, mean age 10.7 ± 3.1 years. Visual impairment (uncorrected VA ≤ 6/9) was detected in 29.4% of children, while 2.0% had moderate-severe visual impairment (uncorrected VA ≤ 6/24). There were statistically significant differences in prevalence of visual impairment between the studied cities (p < 0.05), with the highest prevalence in Abu Redis. Prevalence of visual impairment was significantly higher among girls (p < 0.05) and those with positive consanguinity (p < 0.05). Bedouin children showed significantly lower prevalences of visual impairment. Only age was a reliable predictor of visual impairment (odds ratio 0.94, p < 0.0001). Ophthalmic examination revealed other disorders, e.g. dry eye (4.74%), squint (2.37%), exophthalmos (1.58%) and ptosis (0.79%). VA significantly improved in children who received spectacles (p < 0.001). A total of 29.4% of South Sinai children had some form of visual impairment, 90.32% of which comprised refractive errors (mainly astigmatism) which were significantly corrected with eyeglasses. VA screening and correction of refractive errors are of the utmost importance for ensuring better visual outcomes and improved school performance.

Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction?

PubMed Central

Hastings, Gareth D.; Marsack, Jason D.; Nguyen, Lan Chi; Cheng, Han; Applegate, Raymond A.

2017-01-01

Purpose To prospectively examine whether using the visual image quality metric, visual Strehl (VSX), to optimise objective refraction from wavefront error measurements can provide equivalent or better visual performance than subjective refraction and which refraction is preferred in free viewing. Methods Subjective refractions and wavefront aberrations were measured on 40 visually-normal eyes of 20 subjects, through natural and dilated pupils. For each eye a sphere, cylinder, and axis prescription was also objectively determined that optimised visual image quality (VSX) for the measured wavefront error. High contrast (HC) and low contrast (LC) logMAR visual acuity (VA) and short-term monocular distance vision preference were recorded and compared between the VSX-objective and subjective prescriptions both undilated and dilated. Results For 36 myopic eyes, clinically equivalent (and not statistically different) HC VA was provided with both the objective and subjective refractions (undilated mean ±SD was −0.06 ±0.04 with both refractions; dilated was −0.05 ±0.04 with the objective, and −0.05 ±0.05 with the subjective refraction). LC logMAR VA provided by the objective refraction was also clinically equivalent and not statistically different to that provided by the subjective refraction through both natural and dilated pupils for myopic eyes. In free viewing the objective prescription was preferred over the subjective by 72% of myopic eyes when not dilated. For four habitually undercorrected high hyperopic eyes, the VSX-objective refraction was more positive in spherical power and VA poorer than with the subjective refraction. Conclusions A method of simultaneously optimising sphere, cylinder, and axis from wavefront error measurements, using the visual image quality metric VSX, is described. In myopic subjects, visual performance, as measured by HC and LC VA, with this VSX-objective refraction was found equivalent to that provided by subjective refraction, and was typically preferred over subjective refraction. Subjective refraction was preferred by habitually undercorrected hyperopic eyes. PMID:28370389

Visual Auras in Epilepsy and Migraine - An Analysis of Clinical Characteristics.

PubMed

Hartl, Elisabeth; Angel, Jose; Rémi, Jan; Schankin, Christoph J; Noachtar, Soheyl

2017-06-01

To evaluate the characteristics of visual auras (VA) in epilepsy and migraine. Both disorders are usually diagnosed on clinical grounds, but differentiation might be challenging in isolated auras or because of the similar presentation in migraine and epilepsy. A retrospective study of two cohorts was performed to compare the VA characteristics of 27 epilepsy patients and 27 age-matched migraine patients. The duration of VA was significantly shorter in epilepsy (median: 56s; 1st quartile Q1: 26s; 3rd quartile Q3: 130s) than in migraine (20 min; Q1: 10 min; Q3: 30 min) (P < .0001). A cutoff duration of ≥5 minutes identified all migraine patients (100% sensitivity, 92% specificity). VAs of epileptic etiology were characterized by restriction to a visual hemifield (74.1% vs 29.6% in migraine, P = .0024) with stereotypic affection of one hemifield (55.5% vs 7.4% in migraine, P = 0.0003). Centrifugal or centripetal spread of visual phenomena only occurred in migraine (37.0%), but not in epilepsy (P = 0.0007). If present, accompanying symptoms such as nausea/vomiting (19/27) or photo-/phonophobia (17/27) identify migrainous auras (vs 0/27 in the epilepsy patients; P < .0001). Headache presented in all migraine patients, but was also observed in six of the epilepsy patients during cephalic auras or the postictal phase (P < .0001). None of the visual migrainous auras evolved into an epileptic seizure, a concept called migralepsy. Several clinical characteristics differentiate VA of epileptic and migrainous origin - if presenting in classical manner. Additional EEG evaluations should be performed in patients with VA of unclear etiology and epileptic VA features added to current classifications to increase their discriminatory power. © 2017 American Headache Society.

Visual acuity measured with luminance-modulated and contrast-modulated noise letter stimuli in young adults and adults above 50 years old

PubMed Central

Woi, Pui Juan; Kaur, Sharanjeet; Waugh, Sarah J.; Hairol, Mohd Izzuddin

2016-01-01

The human visual system is sensitive in detecting objects that have different luminance level from their background, known as first-order or luminance-modulated (LM) stimuli. We are also able to detect objects that have the same mean luminance as their background, only differing in contrast (or other attributes). Such objects are known as second-order or contrast-modulated (CM), stimuli. CM stimuli are thought to be processed in higher visual areas compared to LM stimuli, and may be more susceptible to ageing. We compared visual acuities (VA) of five healthy older adults (54.0±1.83 years old) and five healthy younger adults (25.4±1.29 years old) with LM and CM letters under monocular and binocular viewing. For monocular viewing, age had no effect on VA [F(1, 8)= 2.50, p> 0.05]. However, there was a significant main effect of age on VA under binocular viewing [F(1, 8)= 5.67, p< 0.05].  Binocular VA with CM letters in younger adults was approximately two lines better than that in older adults. For LM, binocular summation ratios were similar for older (1.16±0.21) and younger (1.15±0.06) adults. For CM, younger adults had higher binocular summation ratio (1.39±0.08) compared to older adults (1.12±0.09). Binocular viewing improved VA with LM letters for both groups similarly. However, in older adults, binocular viewing did not improve VA with CM letters as much as in younger adults. This could reflect a decline of higher visual areas due to ageing process, most likely higher than V1, which may be missed if measured with luminance-based stimuli alone. PMID:28184281

Increases in the prevalence of reduced visual acuity and myopia in Chinese children in Guangzhou over the past 20 years.

PubMed

Xiang, F; He, M; Zeng, Y; Mai, J; Rose, K A; Morgan, I G

2013-12-01

To estimate the prevalence of myopia based on reduced unaided visual acuity (VA) in Chinese school children over the past 20 years. Guangzhou school health authorities have measured VA on Grade 1-12 students from 1988 to 2007 annually, using a LogMAR tumbling E chart. VA is reported as Snellen categories: normal (VA ≥ 6/6), mildly reduced (6/9 < VA <6/6), moderately reduced (6/18 < VA ≤ 6/9), and severely reduced VA (VA ≤ 6/18). In 1988, over 80% of children in Grade 1 (age 6 years) and about 30% in Grade 12 (age 17 years) had normal unaided VA. By 2007, this dropped to only 60% in Grade 1 and about 10% in Grade 12. Conversely, the prevalence of moderately and severely reduced unaided VA increased from 6.2% in Grade 1 and 62.5% in Grade 12 in 1988 to 14.5% in Grade 1 and 84.11% in Grade 12 in 2007. This rate was unchanged from 2003 to 2007 at both the Grade 1 and Grade 12 levels. In Guangzhou, the prevalence of reduced unaided VA has increased markedly in the past 20 years, but has stabilized in the past few years. This increase may result from environmental changes, such as increased schooling intensity and urbanization.

Visual acuity with simulated and real astigmatic defocus.

PubMed

Ohlendorf, Arne; Tabernero, Juan; Schaeffel, Frank

2011-05-01

To compare the effects of "simulated" and "real" spherical and astigmatic defocus on visual acuity (VA). VA was determined with letter charts that were blurred by calculated spherical or astigmatic defocus (simulated defocus) or were seen through spherical or astigmatic trial lenses (real defocus). Defocus was simulated using ZEMAX and the Liou-Brennan eye model. Nine subjects participated [mean age, 27.2 ± 1.8 years; logarithm of the minimum angle of resolution (logMAR), -0.1]. Three different experiments were conducted in which VA was reduced by 20% (logMAR 0.0), 50% (logMAR 0.2), or 75% (logMAR 0.5) by either (1) imposing positive spherical defocus, (2) imposing positive and negative astigmatic defocus in three axes (0, 45, and 90°), and (3) imposing cross-cylinder defocus in the same three axes as in (2). Experiment (1): there were only minor differences in VA with simulated and real positive spherical defocus. Experiment (2): simulated astigmatic defocus reduced VA twice as much as real astigmatic defocus in all tested axes (p < 0.01 in all cases). Experiment (3): simulated cross-cylinder defocus reduced VA much more than real cross-cylinder defocus (p < 0.01 in all cases), similarly for all three tested axes. The visual system appears more tolerant against "real" spherical, astigmatic, and cross-cylinder defocus than against "simulated" blur. Possible reasons could be (1) limitations in the modeling procedures to simulate defocus, (2) higher ocular aberrations, and (3) fluctuations of accommodation. However, the two optical explanations (2) and (3) cannot account for the magnitude of the effect, and (1) was carefully analyzed. It is proposed that something may be special about the visual processing of real astigmatic and cross-cylinder defocus-because they have less effect on VA than simulations predict.

Control of the vertebral artery from a posterior approach: a technical report.

PubMed

Ye, Jason Y; Ayyash, Omar M; Eskander, Mark S; Kang, James D

2014-06-01

Vertebral artery (VA) injury is a rare but potentially devastating complication of cervical spinal fusion. The Magerl and Harms techniques are associated with a rate between 0% to 8% and 0% to 5%, respectively. Most of reported VA injuries are related to surgical exposure or screw placement, which in turn is likely due to variability in VA anatomy. The purpose of this report was to present the case of a 77-year-old woman, with a history of right VA occlusion, who sustained an intraoperative left VA injury during posterior cervical spine fusion and the subsequent intraoperative and postoperative management strategies. This is a single-patient case report. The patient was placed prone and into Mayfield tongs. A midline incision was made, and dissection was carried down to the lamina and facet joints from occiput to T2. During dissection, she sustained a left-sided VA injury, which was subsequently controlled. The patient was doing well at her 1-year postoperative visit without any residual neurologic deficits. Her severe neck pain had resolved. A detailed understanding of VA anatomy of each individual patient is paramount. There are four types of anomalies: intraforaminal; extraforaminal; arterial; and anomalies of the surrounding bony and soft-tissue architecture. In the event of a posterior intraoperative VA injury, we outlined an algorithm to deal with this complication: control bleeding temporarily to gain visualization of the arterial injury; remove lateral masses and tissue to adequately visualize the arterial injury; once visualized, control the bleeding and see if there are any neuromonitoring changes as a result of the VA occlusion; and proceed with definitive control of the artery by either repair or ligation. Copyright © 2014 Elsevier Inc. All rights reserved.

Prevalence and Causes of Visual Impairment in Fundong District, North West Cameroon: Results of a Population-Based Survey.

PubMed

Oye, Joseph; Mactaggart, Islay; Polack, Sarah; Schmidt, Elena; Tamo, Violet; Okwen, Marvice; Kuper, Hannah

2017-12-01

To estimate the prevalence and causes of visual impairment in Fundong Health District, North West Cameroon. A total of 51 clusters of 80 people (all ages) were sampled with probability proportionate to size and compact segment sampling. Visual acuity (VA) was measured with a tumbling "E" chart. An ophthalmic nurse examined people with VA<6/18 in either eye. The presence of hearing and physical impairments were assessed using clinical examination, and self-reported visual problems using the Washington Group Short Set. In total, 4080 people were enumerated of whom 3567 were screened (response rate 87%). The overall prevalence of visual impairment was 2.3% (95% CI 1.8-3.0%) and blindness was 0.6% (0.3-1.0%). The prevalence of both blindness and visual impairment increased rapidly with age, so that the vast majority of cases of visual impairment (84%) and blindness (82%) were in people aged 50+. Posterior segment disease and cataract were the main causes of blindness and visual impairment, with refractive error also an important cause of visual impairment. Cataract surgical coverage (proportion of all cataracts that had received surgery) was relatively high (87% of people at VA<6/60). Post-surgery outcomes were poor, with 31% of operated eyes having VA<6/60. Among the 82 people with visual impairment, 22% had a physical impairment or epilepsy and 30% had a hearing impairment. Self-reported difficulties in vision were relatively closely related to clinical measures of visual impairment. Ophthalmic programmes in Cameroon need to incorporate control of posterior segment diseases while also working to improve outcomes after cataract surgery.

Baseline predictors for one-year visual outcomes with ranibizumab or bevacizumab for neovascular age-related macular degeneration.

PubMed

Ying, Gui-shuang; Huang, Jiayan; Maguire, Maureen G; Jaffe, Glenn J; Grunwald, Juan E; Toth, Cynthia; Daniel, Ebenezer; Klein, Michael; Pieramici, Dante; Wells, John; Martin, Daniel F

2013-01-01

To determine the baseline predictors of visual acuity (VA) outcomes 1 year after treatment with ranibizumab or bevacizumab for neovascular age-related macular degeneration (AMD). Cohort study within the Comparison of Age-related Macular Degeneration Treatments Trials (CATT). A total of 1105 participants with neovascular AMD, baseline VA 20/25 to 20/320, and VA measured at 1 year. Participants were randomly assigned to ranibizumab or bevacizumab on a monthly or as-needed schedule. Masked readers evaluated fundus morphology and features on optical coherence tomography (OCT). Visual acuity was measured using electronic VA testing. Independent predictors were identified using regression techniques. The VA score, VA score change from baseline, and ≥3-line gain at 1 year. At 1 year, the mean VA score was 68 letters, mean improvement from baseline was 7 letters, and 28% of participants gained ≥3 lines. Older age, larger area of choroidal neovascularization (CNV), and elevation of retinal pigment epithelium (RPE) were associated with worse VA (all P<0.005), less gain in VA (all P<0.02), and a lower proportion gaining ≥3 lines (all P<0.04). Better baseline VA was associated with better VA at 1 year, less gain in VA, and a lower proportion gaining ≥3 lines (all P<0.0001). Predominantly or minimally classic lesions were associated with worse VA than occult lesions (66 vs. 69 letters; P=0.0003). Retinal angiomatous proliferans (RAP) lesions were associated with more gain in VA (10 vs. 7 letters; P=0.03) and a higher proportion gaining ≥3 lines (odds ratio, 1.9; 95% confidence interval, 1.2-3.1). Geographic atrophy (GA) was associated with worse VA (64 vs. 68 letters; P=0.02). Eyes with total foveal thickness in the second quartile (325-425 μm) had the best VA (P=0.01) and were most likely to gain ≥3 lines (P=0.004). Predictors did not vary by treatment group. For all treatment groups, older age, better baseline VA, larger CNV area, predominantly or minimally classic lesion, absence of RAP lesion, presence of GA, greater total fovea thickness, and RPE elevation on optical coherence tomography were independently associated with less improvement in VA at 1 year. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Impact of the Ability to Divide Attention on Reading Performance in Glaucoma.

PubMed

Swenor, Bonnielin K; Varadaraj, Varshini; Dave, Paulomi; West, Sheila K; Rubin, Gary S; Ramulu, Pradeep Y

2017-05-01

To determine if the ability to divide attention affects the relationship between glaucoma-related vision loss and reading speed. Better eye mean deviation (MD), contrast sensitivity (CS), and better-eye distance visual acuity (VA) were measured in 28 participants with glaucoma and 21 controls. Reading speeds were assessed using MNRead, IRest, and sustained silent reading tests (words per minute, wpm). The ability to divide attention was measured using the Brief Test of Attention (BTA; scored 0-10). Multivariable linear regression models were used to determine the relationship between visual factors and reading speeds. Effect modification by BTA score (low BTA: <7; high BTA: ≥7) was examined. Worse CS (per 0.1 log unit) was associated with slower maximum reading speed on MNRead test for participants with low BTA scores (β = -9 wpm; 95% confidence interval [CI]: -16, -2), but not for those with high BTA scores (β = -2 wpm; 95% CI: -6, +2). Similarly, for the IRest test, worse CS was associated with slower reading speeds (β = -12 wpm; 95% CI: -20, -4) among those with low, but not high BTA scores (β = -4 wpm; 95% CI: -10, +2). For the sustained silent reading test, glaucoma status (versus controls), worse visual field (VF) MD (per 5 dB), and worse CS were associated with 39%, 21%, and 19% slower reading speeds, respectively, for those with low BTA scores (P < 0.05), but these associations were not significant among those with high BTA scores (P > 0.1 for all). Decreased ability to divide attention, indicated by lower BTA scores, is associated with slower reading speeds in glaucoma with reduced CS and VF defects.

Impact of the Ability to Divide Attention on Reading Performance in Glaucoma

PubMed Central

Swenor, Bonnielin K.; Varadaraj, Varshini; Dave, Paulomi; West, Sheila K.; Rubin, Gary S.; Ramulu, Pradeep Y.

2017-01-01

Purpose To determine if the ability to divide attention affects the relationship between glaucoma-related vision loss and reading speed. Methods Better eye mean deviation (MD), contrast sensitivity (CS), and better-eye distance visual acuity (VA) were measured in 28 participants with glaucoma and 21 controls. Reading speeds were assessed using MNRead, IRest, and sustained silent reading tests (words per minute, wpm). The ability to divide attention was measured using the Brief Test of Attention (BTA; scored 0–10). Multivariable linear regression models were used to determine the relationship between visual factors and reading speeds. Effect modification by BTA score (low BTA: <7; high BTA: ≥7) was examined. Results Worse CS (per 0.1 log unit) was associated with slower maximum reading speed on MNRead test for participants with low BTA scores (β = −9 wpm; 95% confidence interval [CI]: −16, −2), but not for those with high BTA scores (β = −2 wpm; 95% CI: −6, +2). Similarly, for the IRest test, worse CS was associated with slower reading speeds (β = −12 wpm; 95% CI: −20, −4) among those with low, but not high BTA scores (β = −4 wpm; 95% CI: −10, +2). For the sustained silent reading test, glaucoma status (versus controls), worse visual field (VF) MD (per 5 dB), and worse CS were associated with 39%, 21%, and 19% slower reading speeds, respectively, for those with low BTA scores (P < 0.05), but these associations were not significant among those with high BTA scores (P > 0.1 for all). Conclusions Decreased ability to divide attention, indicated by lower BTA scores, is associated with slower reading speeds in glaucoma with reduced CS and VF defects. PMID:28460047

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice

PubMed Central

Yusifov, Rashad

2018-01-01

Abstract For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162–P182] SC-raised mice. This was indeed the case: 40–50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice. PMID:29379877

A population-based survey of visual impairment and its correlates in Mahabubnagar district, Telangana State, India.

PubMed

Mactaggart, Islay; Polack, Sarah; Murthy, Gvs; Kuper, Hannah

2018-06-01

To estimate the prevalence and correlates of visual impairment in Mahabubnagar district, Telangana, India. Fifty-one clusters of 80 people (all ages) were sampled with probability proportionate to size. Households within clusters were selected through the compact segment sampling. Visual acuity (VA) was measured with a tumbling "E" chart. An Ophthalmic Assistant or Vision Technician examined people with VA<6/12 in either eye. Other impairments (hearing, physical) were clinically assessed and self-reported functional difficulties measured using the Washington Group Extended Set. People with visual impairment and age-sex matched controls with normal vision were interviewed about poverty, employment and education. 4,125 people were enumerated and 3,574 screened (86.6%). The prevalence of visual impairment (VA<6/12) was 8.0% (95% CI = 6.9-9.4%) and blindness was 0.4% (0.2-0.9%), and both increased rapidly with age. Uncorrected refractive error was the leading cause of visual impairment, and cataract the leading cause of blindness. Cataract surgical coverage (proportion of all cataracts that had received surgery) was relatively low (41% of people at VA<6/60), while the post-surgery outcomes were good (81% of operated eyes had presenting VA≥6/18). Among the 287 people with visual impairment, 15% had a moderate/severe physical impairment or epilepsy and 25% had a moderate/severe hearing impairment. Self-reported difficulties in vision were relatively closely related to visual acuity. People with visual impairment were more likely to be in the poorest quartile (OR = 1.9, 95% CI = 1.0-3.4) or unemployed (5.0, 2.2-10.0), compared to controls. Visual impairment was common in Mahabubnagar district, was mostly avoidable, and was correlated with poverty markers.

Using the Freiburg Acuity and Contrast Test to measure visual performance in USAF personnel after PRK.

PubMed

Dennis, Richard J; Beer, Jeremy M A; Baldwin, J Bruce; Ivan, Douglas J; Lorusso, Frank J; Thompson, William T

2004-07-01

Photorefractive keratectomy (PRK) may be an alternative to spectacle and contact lens wear for United States Air Force (USAF) aircrew and may offer some distinct advantages in operational situations. However, any residual corneal haze or scar formation from PRK could exacerbate the disabling effects of a bright glare source on a complex visual task. The USAF recently completed a longitudinal clinical evaluation of the long-term effects of PRK on visual performance, including the experiment described herein. After baseline data were collected, 20 nonflying active duty USAF personnel underwent PRK. Visual performance was then measured at 6, 12, and 24 months after PRK. Visual acuity (VA) and contrast sensitivity (CS) data were collected by using the Freiburg Acuity and Contrast Test (FrACT), with the subject viewing half of the runs through a polycarbonate windscreen. Experimental runs were completed under 3 glare conditions: no glare source and with either a broadband or a green laser (532-nm) glare annulus (luminance approximately 6090 cd/m) surrounding the Landolt C stimulus. Systematic effects of PRK on VA relative to baseline were not identified. However, VA was almost 2 full Snellen lines worse with the laser glare source in place versus the broadband glare source. A significant drop-off was observed in CS performance after PRK under conditions of no glare and broadband glare; this was the case both with and without the windscreen. As with VA, laser glare disrupted CS performance significantly and more than broadband glare did. PRK does not appear to have affected VA, but the changes in CS might represent a true decline in visual performance. The greater disruptive effects from laser versus broadband glare may be a result of increased masking from coherent spatial noise (speckle) surrounding the laser stimulus.

The visual system of diurnal raptors: updated review.

PubMed

González-Martín-Moro, J; Hernández-Verdejo, J L; Clement-Corral, A

2017-05-01

Diurnal birds of prey (raptors) are considered the group of animals with highest visual acuity (VA). The purpose of this work is to review all the information recently published about the visual system of this group of animals. A bibliographic search was performed in PubMed. The algorithm used was (raptor OR falcon OR kestrel OR hawk OR eagle) AND (vision OR «visual acuity» OR eye OR macula OR retina OR fovea OR «nictitating membrane» OR «chromatic vision» OR ultraviolet). The search was restricted to the «Title» and «Abstract» fields, and to non-human species, without time restriction. The proposed algorithm located 97 articles. Birds of prey are endowed with the highest VA of the animal kingdom. However most of the works study one individual or a small group of individuals, and the methodology is heterogeneous. The most studied bird is the Peregrine falcon (Falco peregrinus), with an estimated VA of 140 cycles/degree. Some eagles are endowed with similar VA. The tubular shape of the eye, the large pupil, and a high density of photoreceptors make this extraordinary VA possible. In some species, histology and optic coherence tomography demonstrate the presence of 2foveas. The nasal fovea (deep fovea) has higher VA. Nevertheless, the exact function of each fovea is unknown. The vitreous contained in the deep fovea could behave as a third lens, adding some magnification to the optic system. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

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.

Optimized classification of 18F-Florbetaben PET scans as positive and negative using an SUVR quantitative approach and comparison to visual assessment.

PubMed

Bullich, Santiago; Seibyl, John; Catafau, Ana M; Jovalekic, Aleksandar; Koglin, Norman; Barthel, Henryk; Sabri, Osama; De Santi, Susan

2017-01-01

Standardized uptake value ratios (SUVRs) calculated from cerebral cortical areas can be used to categorize 18 F-Florbetaben (FBB) PET scans by applying appropriate cutoffs. The objective of this work was first to generate FBB SUVR cutoffs using visual assessment (VA) as standard of truth (SoT) for a number of reference regions (RR) (cerebellar gray matter (GCER), whole cerebellum (WCER), pons (PONS), and subcortical white matter (SWM)). Secondly, to validate the FBB PET scan categorization performed by SUVR cutoffs against the categorization made by post-mortem histopathological confirmation of the Aβ presence. Finally, to evaluate the added value of SUVR cutoff categorization to VA. SUVR cutoffs were generated for each RR using FBB scans from 143 subjects who were visually assessed by 3 readers. SUVR cutoffs were validated in 78 end-of life subjects using VA from 8 independent blinded readers (3 expert readers and 5 non-expert readers) and histopathological confirmation of the presence of neuritic beta-amyloid plaques as SoT. Finally, the number of correctly or incorrectly classified scans according to pathology results using VA and SUVR cutoffs was compared. Composite SUVR cutoffs generated were 1.43 (GCER), 0.96 (WCER), 0.78 (PONS) and 0.71 (SWM). Accuracy values were high and consistent across RR (range 83-94% for histopathology, and 85-94% for VA). SUVR cutoff performed similarly as VA but did not improve VA classification of FBB scans read either by expert readers or the majority read but provided higher accuracy than some non-expert readers. The accurate scan classification obtained in this study supports the use of VA as SoT to generate site-specific SUVR cutoffs. For an elderly end of life population, VA and SUVR cutoff categorization perform similarly in classifying FBB scans as Aβ-positive or Aβ-negative. These results emphasize the additional contribution that SUVR cutoff classification may have compared with VA performed by non-expert readers.

Validity of Teacher-Based Vision Screening and Factors Associated with the Accuracy of Vision Screening in Vietnamese Children.

PubMed

Paudel, Prakash; Kovai, Vilas; Naduvilath, Thomas; Phuong, Ha Thanh; Ho, Suit May; Giap, Nguyen Viet

2016-01-01

To assess validity of teacher-based vision screening and elicit factors associated with accuracy of vision screening in Vietnam. After brief training, teachers independently measured visual acuity (VA) in 555 children aged 12-15 years in Ba Ria - Vung Tau Province. Teacher VA measurements were compared to those of refractionists. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for uncorrected VA (UVA) and presenting VA (PVA) 20/40 or worse in either eye. Chi-square, Fisher's exact test and multivariate logistic regression were used to assess factors associated with accuracy of vision screening. Level of significance was set at 5%. Trained teachers in Vietnam demonstrated 86.7% sensitivity, 95.7% specificity, 86.7% positive predictive value and 95.7% negative predictive value in identifying children with visual impairment using the UVA measurement. PVA measurement revealed low accuracy for teachers, which was significantly associated with child's age, sex, spectacle wear and myopic status, but UVA measurement showed no such associations. Better accuracy was achieved in measurement of VA and identification of children with visual impairment using UVA measurement compared to PVA. UVA measurement is recommended for teacher-based vision screening programs.

Indocyanine Green Videoangiography Transoptic Visualization and Clipping Confirmation of an Optic Splitting Ophthalmic Artery Aneurysm.

PubMed

Rustemi, Oriela; Cester, Giacomo; Causin, Francesco; Scienza, Renato; Della Puppa, Alessandro

2016-06-01

Ophthalmic artery aneurysms with medial and superior projection in exceptionally rare cases can split the optic nerve. Treatment of these aneurysms is challenging, because the aneurysm dome is hidden from the optic nerve, rendering its visualization and clipping confirmation difficult. In addition, optic nerve function should be preserved during surgical maneuvers. Preoperative detection of this growing feature is usually missing. We illustrate the first case of indocyanine green videoangiography (ICG-VA) application in an optic penetrating ophthalmic artery aneurysm treatment. A 57-year-old woman presented with temporal hemianopsia, slight right visual acuity deficit, and new onset of headache. The cerebral angiography detected a right ophthalmic artery aneurysm medially and superiorly projecting. The A1 tract of the ipsilateral anterior cerebral artery was elevated and curved, being suspicious for an under optic aneurysm growth. Surgery was performed. Initially the aneurysm was not visible. ICG-VA permitted the transoptic aneurysm visualization. After optic canal opening, the aneurysm was clipped and transoptic ICG-VA confirmed the aneurysm occlusion. ICG-VA showed also the slight improvement of the optic nerve pial vascularization. Postoperatively, the visual acuity was 10/10 and the hemianopsia did not worsen. The elevation and curve of the A1 tract in medially and superiorly projecting ophthalmic aneurysms may be an indirect sign of under optic growth, or optic splitting aneurysms. ICG-VA transoptic aneurysm detection and occlusion confirmation reduces the surgical maneuvers on the optic nerve, contributing to function preservation. Copyright © 2016 Elsevier Inc. All rights reserved.

Social Determinants and Their Impact on Visual Impairment in Southern Mexico.

PubMed

Jimenez-Corona, Aida; Jimenez-Corona, Maria E; Ponce-de-Leon, Samuel; Chavez-Rodriguez, Mariela; Graue-Hernandez, Enrique O

2015-01-01

Visual impairment in disadvantaged populations in Mexico has been scarcely reported. We compared the prevalence of visual impairment and its associated risk factors in populations in rural compared to urban areas of the Mexican southern state of Chiapas. In a population-based study, the prevalence of visual impairment in rural and urban areas of Comitan, Chiapas, was estimated. All eligible individuals aged ≥20 years living in rural areas were invited to participate; persons from urban areas were chosen randomly. Individuals were considered of indigenous (IND) origin either by self-report or if they spoke an IND language. Visual acuity (VA) and pinhole VA were measured using a tumbling E chart. VA was defined as normal (better than or equal to 20/60), moderate impairment (worse than 20/60 but better than or equal to 20/200), severe impairment (worse than 20/200 but better than or equal to 20/400), or blindness (worse than 20/400). Data on VA were obtained from 969 persons (610 rural, 359 urban) whose mean age was 43.3 years (standard deviation 15.6 years). Prevalence of moderate visual impairment was higher in rural (10.2%, 95% confidence interval, CI, 7.2-14.2%) than urban (3.9%, 95% CI 1.9-7.9%) areas (p < 0.001). Persons with moderate visual impairment were older and less educated (both p < 0.001). Rural individuals aged 50 years and older had 4.4 times (95% CI 1.8-11.3, p = 0.002) the likelihood of having moderate visual impairment compared with urban persons. Unfavorable socioeconomic conditions were associated with higher prevalence of moderate visual impairment in rural compared with urban populations in Mexico.

A participatory approach to designing and enhancing integrated health information technology systems for veterans: protocol.

PubMed

Haun, Jolie N; Nazi, Kim M; Chavez, Margeaux; Lind, Jason D; Antinori, Nicole; Gosline, Robert M; Martin, Tracey L

2015-02-27

The Department of Veterans Affairs (VA) has developed health information technologies (HIT) and resources to improve veteran access to health care programs and services, and to support a patient-centered approach to health care delivery. To improve VA HIT access and meaningful use by veterans, it is necessary to understand their preferences for interacting with various HIT resources to accomplish health management related tasks and to exchange information. The objective of this paper was to describe a novel protocol for: (1) developing a HIT Digital Health Matrix Model; (2) conducting an Analytic Hierarchy Process called pairwise comparison to understand how and why veterans want to use electronic health resources to complete tasks related to health management; and (3) developing visual modeling simulations that depict veterans' preferences for using VA HIT to manage their health conditions and exchange health information. The study uses participatory research methods to understand how veterans prefer to use VA HIT to accomplish health management tasks within a given context, and how they would like to interact with HIT interfaces (eg, look, feel, and function) in the future. This study includes two rounds of veteran focus groups with self-administered surveys and visual modeling simulation techniques. This study will also convene an expert panel to assist in the development of a VA HIT Digital Health Matrix Model, so that both expert panel members and veteran participants can complete an Analytic Hierarchy Process, pairwise comparisons to evaluate and rank the applicability of electronic health resources for a series of health management tasks. This protocol describes the iterative, participatory, and patient-centered process for: (1) developing a VA HIT Digital Health Matrix Model that outlines current VA patient-facing platforms available to veterans, describing their features and relevant contexts for use; and (2) developing visual model simulations based on direct veteran feedback that depict patient preferences for enhancing the synchronization, integration, and standardization of VA patient-facing platforms. Focus group topics include current uses, preferences, facilitators, and barriers to using electronic health resources; recommendations for synchronizing, integrating, and standardizing VA HIT; and preferences on data sharing and delegation within the VA system. This work highlights the practical, technological, and personal factors that facilitate and inhibit use of current VA HIT, and informs an integrated system redesign. The Digital Health Matrix Model and visual modeling simulations use knowledge of veteran preferences and experiences to directly inform enhancements to VA HIT and provide a more holistic and integrated user experience. These efforts are designed to support the adoption and sustained use of VA HIT to support patient self-management and clinical care coordination in ways that are directly aligned with veteran preferences.

A Participatory Approach to Designing and Enhancing Integrated Health Information Technology Systems for Veterans: Protocol

PubMed Central

Nazi, Kim M; Chavez, Margeaux; Lind, Jason D; Antinori, Nicole; Gosline, Robert M; Martin, Tracey L

2015-01-01

Background The Department of Veterans Affairs (VA) has developed health information technologies (HIT) and resources to improve veteran access to health care programs and services, and to support a patient-centered approach to health care delivery. To improve VA HIT access and meaningful use by veterans, it is necessary to understand their preferences for interacting with various HIT resources to accomplish health management related tasks and to exchange information. Objective The objective of this paper was to describe a novel protocol for: (1) developing a HIT Digital Health Matrix Model; (2) conducting an Analytic Hierarchy Process called pairwise comparison to understand how and why veterans want to use electronic health resources to complete tasks related to health management; and (3) developing visual modeling simulations that depict veterans’ preferences for using VA HIT to manage their health conditions and exchange health information. Methods The study uses participatory research methods to understand how veterans prefer to use VA HIT to accomplish health management tasks within a given context, and how they would like to interact with HIT interfaces (eg, look, feel, and function) in the future. This study includes two rounds of veteran focus groups with self-administered surveys and visual modeling simulation techniques. This study will also convene an expert panel to assist in the development of a VA HIT Digital Health Matrix Model, so that both expert panel members and veteran participants can complete an Analytic Hierarchy Process, pairwise comparisons to evaluate and rank the applicability of electronic health resources for a series of health management tasks. Results This protocol describes the iterative, participatory, and patient-centered process for: (1) developing a VA HIT Digital Health Matrix Model that outlines current VA patient-facing platforms available to veterans, describing their features and relevant contexts for use; and (2) developing visual model simulations based on direct veteran feedback that depict patient preferences for enhancing the synchronization, integration, and standardization of VA patient-facing platforms. Focus group topics include current uses, preferences, facilitators, and barriers to using electronic health resources; recommendations for synchronizing, integrating, and standardizing VA HIT; and preferences on data sharing and delegation within the VA system. Conclusions This work highlights the practical, technological, and personal factors that facilitate and inhibit use of current VA HIT, and informs an integrated system redesign. The Digital Health Matrix Model and visual modeling simulations use knowledge of veteran preferences and experiences to directly inform enhancements to VA HIT and provide a more holistic and integrated user experience. These efforts are designed to support the adoption and sustained use of VA HIT to support patient self-management and clinical care coordination in ways that are directly aligned with veteran preferences. PMID:25803324

Visual acuity, self-reported vision and falls in the EPIC-Norfolk Eye study.

PubMed

Yip, Jennifer L Y; Khawaja, Anthony P; Broadway, David; Luben, Robert; Hayat, Shabina; Dalzell, Nichola; Bhaniani, Amit; Wareham, Nicholas; Khaw, Kay-Tee; Foster, Paul J

2014-03-01

To examine the relationship between visual acuity (VA) and self-reported vision (SRV) in relation to falls in 8317 participants of the European Prospective Investigation into Cancer-Norfolk Eye study. All participants completed a health questionnaire that included a question regarding SRV and questions regarding the number of falls in the past year. Distance VA was measured using a logMAR chart for each eye. Poor SRV was defined as those reporting fair or poor distance vision. The relationship between VA and SRV and self-rated falls was analysed by logistic regression, adjusting for age, sex, physical activity, body mass index, chronic disease, medication use and grip strength. Of 8317 participants, 26.7% (95% CI 25.7% to 27.7%) had fallen in the past 12 months. Worse VA and poorer SRV were associated with one or more falls in multivariable analysis (OR for falls=1.31, 95% CI 1.04 to 1.66 and OR=1.32, 95% CI 1.09 to 1.61, respectively). Poorer SRV was significantly associated with falls even after adjusting for VA (OR=1.28, 95% CI 1.05 to 1.57). SRV was associated with falls independently of VA and could be used as a simple proxy measure for other aspects of visual function to detect people requiring vision-related falls interventions.

Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction?

PubMed

Hastings, Gareth D; Marsack, Jason D; Nguyen, Lan Chi; Cheng, Han; Applegate, Raymond A

2017-05-01

To prospectively examine whether using the visual image quality metric, visual Strehl (VSX), to optimise objective refraction from wavefront error measurements can provide equivalent or better visual performance than subjective refraction and which refraction is preferred in free viewing. Subjective refractions and wavefront aberrations were measured on 40 visually-normal eyes of 20 subjects, through natural and dilated pupils. For each eye a sphere, cylinder, and axis prescription was also objectively determined that optimised visual image quality (VSX) for the measured wavefront error. High contrast (HC) and low contrast (LC) logMAR visual acuity (VA) and short-term monocular distance vision preference were recorded and compared between the VSX-objective and subjective prescriptions both undilated and dilated. For 36 myopic eyes, clinically equivalent (and not statistically different) HC VA was provided with both the objective and subjective refractions (undilated mean ± S.D. was -0.06 ± 0.04 with both refractions; dilated was -0.05 ± 0.04 with the objective, and -0.05 ± 0.05 with the subjective refraction). LC logMAR VA provided by the objective refraction was also clinically equivalent and not statistically different to that provided by the subjective refraction through both natural and dilated pupils for myopic eyes. In free viewing the objective prescription was preferred over the subjective by 72% of myopic eyes when not dilated. For four habitually undercorrected high hyperopic eyes, the VSX-objective refraction was more positive in spherical power and VA poorer than with the subjective refraction. A method of simultaneously optimising sphere, cylinder, and axis from wavefront error measurements, using the visual image quality metric VSX, is described. In myopic subjects, visual performance, as measured by HC and LC VA, with this VSX-objective refraction was found equivalent to that provided by subjective refraction, and was typically preferred over subjective refraction. Subjective refraction was preferred by habitually undercorrected hyperopic eyes. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

The United Kingdom Diabetic Retinopathy Electronic Medical Record Users Group, Report 1: baseline characteristics and visual acuity outcomes in eyes treated with intravitreal injections of ranibizumab for diabetic macular oedema.

PubMed

Egan, Catherine; Zhu, Haogang; Lee, Aaron; Sim, Dawn; Mitry, Danny; Bailey, Clare; Johnston, Robert; Chakravarthy, Usha; Denniston, Alastair; Tufail, Adnan; Khan, Rehna; Mahmood, Sajjad; Menon, Geeta; Akerele, Toks; Downey, Louise; McKibbin, Martin; Varma, Atul; Lobo, Aires; Wilkinson, Elizabeth; Fitt, Alan; Brand, Christopher; Tsaloumas, Marie; Mandal, Kaveri; Kumar, Vineeth; Natha, Salim; Crabb, David

2017-01-01

To describe baseline characteristics and visual outcome for eyes treated with ranibizumab for diabetic macular oedema (DMO) from a multicentre database. Structured clinical data were anonymised and extracted from an electronic medical record from 19 participating UK centres: age at first injection, ETDRS visual acuity (VA), number of injections, ETDRS diabetic retinopathy (DR) and maculopathy grade at baseline and visits. The main outcomes were change in mean VA from baseline, number of injections and clinic visits and characteristics affecting VA change and DR grade. Data from 12 989 clinic visits was collated from baseline and follow-up for 3103 eyes. Mean age at first treatment was 66 years. Mean VA (letters) for eyes followed at least 2 years was 51.1 (SD=19.3) at baseline, 54.2 (SD: 18.6) and 52.5 (SD: 19.4) at 1 and 2 years, respectively. Mean visual gain was five letters. The proportion of eyes with VA of 72 letters or better was 25% (baseline) and 33% (1 year) for treatment naïve eyes. Eyes followed for at least 6 months received a mean of 3.3 injections over a mean of 6.9 outpatient visits in 1 year. In a large cohort of eyes with DMO treated with ranibizumab injections in the UK, 33% of patients achieved better than or equal to 6/12 in the treated eye at 12 months compared with 25% at baseline. The mean visual gain was five letters. Eyes with excellent VA at baseline maintain good vision at 18 months. 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/.

Shortest Distance From Fovea to Subfoveal Hemorrhage Border Is Important in Patients With Neovascular Age-related Macular Degeneration.

PubMed

Kherani, Saleema; Scott, Adrienne W; Wenick, Adam S; Zimmer-Galler, Ingrid; Brady, Christopher J; Sodhi, Akrit; Meyerle, Catherine; Solomon, Sharon D; Shaukat, Rimsha; Channa, Roomasa; Adeyemo, Olukemi; Handa, James T; Wang, Jiangxia; Campochiaro, Peter A

2018-05-01

To identify factors influencing visual outcome in patients with neovascular age-related macular degeneration (NVAMD) and subfoveal hemorrhage (SFH) treated with anti-vascular endothelial growth factor (VEGF) agents. Retrospective case series. Anti-VEGF-treated eyes with SFH > 1 disc area (DA) were identified (n = 16) and changes in visual acuity (VA) and central subfield thickness (CST) from baseline to last follow-up, along with SFH area, thickness, minimum distance from fovea to SFH border, and time to resolution, were determined. At baseline, mean (± standard error of the mean) size and thickness of SFH were 14.9 ± 2.8 DA and 386.6 ± 46.9 μm, and mean Snellen VA and CST were 20/250 and 591.7 ± 57.0 μm. Median follow-up was 47.6 months. While more than 50% of patients had VA ≤ 20/200 at baseline and all time points through week 48, the percentage of patients with VA ≥ 20/50 increased to 30%-40% at months 6 and 12 and remained stable through month 48. Spearman rank correlation demonstrated 2 independent variables that correlated with good visual outcome, smaller area of SFH at baseline (r = -0.630; P = .009), and high frequency of anti-VEGF injections (r = 0.646; P = .007). In exceptional patients with good visual outcome despite large baseline SFH, shortest distance between the fovea and hemorrhage border significantly correlated with baseline VA (r = -0.503, P = .047) and final VA (r = -0.575, P = .02). Patients with NVAMD and thick SFH, but short distance between fovea and uninvolved retina, can have good visual outcomes when given frequent anti-VEGF injections. Copyright © 2018 Elsevier Inc. All rights reserved.

76 FR 21802 - Advisory Committee on the Readjustment of Veterans Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-18

... VA mental health program activities with special attention to mental health services for retuning war Veterans and on VA's caregiver programs developed to assure support services for severely wounded combat... evaluate the availability and effectiveness of VA programs to meet these needs. On April 28, the Committee...

Color perception differentiates Alzheimer's Disease (AD) from Vascular Dementia (VaD) patients.

PubMed

Arnaoutoglou, N A; Arnaoutoglou, M; Nemtsas, P; Costa, V; Baloyannis, S J; Ebmeier, K P

2017-08-01

Alzheimer's Disease (AD) and Vascular Dementia (VaD) are the most common causes of dementia in older people. Both diseases appear to have similar clinical symptoms, such as deficits in attention and executive function, but specific cognitive domains are affected. Current cohort studies have shown a close relationship between αβ deposits and age-related macular degeneration (Johnson et al., 2002; Ratnayaka et al., 2015). Additionally, a close link between the thinning of the retinal nerve fiber (RNFL) and AD patients has been described, while it has been proposed that AD patients suffer from a non-specific type of color blindness (Pache et al., 2003). Our study included 103 individuals divided into three groups: A healthy control group (n = 35), AD (n = 32) according to DSM-IV-TR, NINCDS-ADRDA criteria, and VaD (n = 36) based on ΝΙΝDS-AIREN, as well as Magnetic Resonance Imaging (MRI) results. The severity of patient's cognitive impairment, was measured with the Mini-Mental State Examination (MMSE) and was classified according to the Reisberg global deterioration scale (GDS). Visual perception was examined using the Ishihara plates: "Ishihara Color Vision Test - 38 Plate." The three groups were not statistically different for demographic data (age, gender, and education). The Ishihara color blindness test has a sensitivity of 80.6% and a specificity of 87.5% to discriminate AD and VaD patients when an optimal (32.5) cut-off value of performance is used. Ishihara Color Vision Test - 38 Plate is a promising potential method as an easy and not time-consuming screening test for the differential diagnosis of dementia between AD and VaD.

Prevalence and causes of visual impairment in Asian and non-Hispanic white preschool children: Multi-ethnic Pediatric Eye Disease Study.

PubMed

Tarczy-Hornoch, Kristina; Cotter, Susan A; Borchert, Mark; McKean-Cowdin, Roberta; Lin, Jesse; Wen, Ge; Kim, Jeniffer; Varma, Rohit

2013-06-01

To determine the prevalence and causes of decreased visual acuity (VA). Population-based cross-sectional study. Multi-ethnic sample of children 30 to 72 months of age identified in Los Angeles. All eligible children underwent a comprehensive ophthalmic evaluation including monocular VA testing, cover testing, cycloplegic autorefraction, fundus evaluation, and VA retesting with refractive correction. Decreased VA was defined as presenting or best-measured VA worse than 20/50 in children 30 to 47 months of age and worse than 20/40 for children 48 months of age and older. The prevalence and causes of decreased VA were determined, for both presenting and best-measured VA, in the better-seeing and the worse-seeing eyes. Prevalence and causes of decreased vision. Presenting VA was assessed in 1840 children and best-measured VA was assessed in 1886 children. Presenting VA was decreased in the worse eye of 4.2% of Asian children and of 3.6% of non-Hispanic white (NHW) children. Close to one-fourth of these cases had no identifiable cause, and 81% of these resolved on retesting. Decreased presenting VA in the worse eye with an identifiable ophthalmic cause was present in 3.4% of Asian children and in 2.6% of NHW children. Decreased presenting VA attributable to simple refractive error (myopia ≥ 0.5 diopters [D]; hyperopia ≥ 3.0 D; astigmatism ≥ 2.0 D or ≥ 1.5 D for children older than 36 months) was present in the worse eye of 2.3% of Asian children and of 1.4% of NHW children and in the better eye of 0.5% of Asian children and of 0.3% of NHW children. Decreased best-measured VA attributable to a cause was present in the worse eye of 1.2% of both Asian children and NHW children and in the better eye of 0.2% of Asian and of 0.3% of NHW children. Amblyopia related to refractive error was the most common cause, and was 10 times as common as ocular disease. Severe visual impairment was rare. Seventy percent of all decreased VA in Asian and NHW preschool children and more than 90% of decreased VA with an identifiable cause is related to refractive error--either uncorrected refractive error or amblyopia resulting from refractive error. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Putative mechanisms mediating tolerance for audiovisual stimulus onset asynchrony.

PubMed

Bhat, Jyoti; Miller, Lee M; Pitt, Mark A; Shahin, Antoine J

2015-03-01

Audiovisual (AV) speech perception is robust to temporal asynchronies between visual and auditory stimuli. We investigated the neural mechanisms that facilitate tolerance for audiovisual stimulus onset asynchrony (AVOA) with EEG. Individuals were presented with AV words that were asynchronous in onsets of voice and mouth movement and judged whether they were synchronous or not. Behaviorally, individuals tolerated (perceived as synchronous) longer AVOAs when mouth movement preceded the speech (V-A) stimuli than when the speech preceded mouth movement (A-V). Neurophysiologically, the P1-N1-P2 auditory evoked potentials (AEPs), time-locked to sound onsets and known to arise in and surrounding the primary auditory cortex (PAC), were smaller for the in-sync than the out-of-sync percepts. Spectral power of oscillatory activity in the beta band (14-30 Hz) following the AEPs was larger during the in-sync than out-of-sync perception for both A-V and V-A conditions. However, alpha power (8-14 Hz), also following AEPs, was larger for the in-sync than out-of-sync percepts only in the V-A condition. These results demonstrate that AVOA tolerance is enhanced by inhibiting low-level auditory activity (e.g., AEPs representing generators in and surrounding PAC) that code for acoustic onsets. By reducing sensitivity to acoustic onsets, visual-to-auditory onset mapping is weakened, allowing for greater AVOA tolerance. In contrast, beta and alpha results suggest the involvement of higher-level neural processes that may code for language cues (phonetic, lexical), selective attention, and binding of AV percepts, allowing for wider neural windows of temporal integration, i.e., greater AVOA tolerance. Copyright © 2015 the American Physiological Society.

Leveraging multidisciplinarity in a visual analytics graduate course.

PubMed

Elmqvist, Niklas; Ebert, David S

2012-01-01

Demand is growing in engineering, business, science, research, and industry for students with visual analytics expertise. However, teaching VA is challenging owing to the multidisciplinary nature of the topic, students' diverse backgrounds, and the corresponding requirements for instructors. This article reports best practices from a VA graduate course at Purdue University, where instructors leveraged these challenges to their advantage instead of trying to mitigate them.

Views and practices of Australian optometrists regarding driving for patients with central visual impairment.

PubMed

Oberstein, Sharon L; Boon, Mei Ying; Chu, Byoung Sun; Wood, Joanne M

2016-09-01

Eye-care practitioners are often required to make recommendations regarding their patients' visual fitness for driving, including patients with visual impairment. This study aimed to understand the perspectives and management strategies adopted by optometrists regarding driving for their patients with central visual impairment. Optometrists were invited to participate in an online survey (from April to June 2012). Items were designed to explore the views and practices adopted by optometrists regarding driving for patients with central visual impairment (visual acuity [VA] poorer than 6/12, normal visual fields, cognitive and physical health), including conditional driver's licences and bioptic telescopes. Closed- and open-ended questions were used. The response rate was 14 per cent (n = 300 valid responses were received). Most respondents (83 per cent) reported that they advised their patients with visual impairment to 'always' or 'sometimes' stop driving. Most were confident in interpreting the visual licensing standards (78 per cent) and advising on legal responsibilities concerning driving (99 per cent). Respondents were familiar with VA requirements for unconditional licensing (98 per cent); however, the median response VA of 6/15 as the poorest VA suggested for conditional licences differed from international practice and Australian medical guidelines released a month prior to the survey's launch. Few respondents reported prescribing bioptic telescopes (two per cent). While 97 per cent of respondents stated that they discussed conditional licences with their patients with visual impairment, relatively few (28 per cent) reported having completed conditional licence applications for such individuals in the previous year. Those who had completed applications were more experienced in years of practice (p = 0.02) and spent more time practising in rural locations (p = 0.03) than those who had not. The majority of Australian optometrists were receptive to the possibilities of driving options for individuals with central visual impairment, although management approaches varied with respect to conditional licensing. © 2016 Optometry Australia.

Long-term surgical outcomes of retinal detachment in patients with Stickler syndrome

PubMed Central

Reddy, Devasis N; Yonekawa, Yoshihiro; Thomas, Benjamin J; Nudleman, Eric D; Williams, George A

2016-01-01

Purpose The aim of the study was to present the long-term anatomical and visual outcomes of retinal detachment repair in patients with Stickler syndrome. Patients and methods This study is a retrospective, interventional, consecutive case series of patients with Stickler syndrome undergoing retinal reattachment surgery from 2009 to 2014 at the Associated Retinal Consultants, William Beaumont Hospital. Results Sixteen eyes from 13 patients were identified. Patients underwent a mean of 3.1 surgical interventions (range: 1–13) with a mean postoperative follow-up of 94 months (range: 5–313 months). Twelve eyes (75%) developed proliferative vitreoretinopathy. Retinal reattachment was achieved in 100% of eyes, with ten eyes (63%) requiring silicone oil tamponade at final follow-up. Mean preoperative visual acuity (VA) was 20/914, which improved to 20/796 at final follow-up (P=0.81). There was a significant correlation between presenting and final VA (P<0.001), and patients with poorer presenting VA were more likely to require silicone oil tamponade at final follow-up (P=0.04). Conclusion Repair of retinal detachment in patients with Stickler syndrome often requires multiple surgeries, and visual outcomes are variable. Presenting VA is significantly predictive of long-term VA outcomes. PMID:27574392

Predicting Glycerophosphoinositol Identities in Lipidomic Datasets Using VaLID (Visualization and Phospholipid Identification)—An Online Bioinformatic Search Engine

PubMed Central

McDowell, Graeme S. V.; Taylor, Graeme P.; Fai, Stephen; Bennett, Steffany A. L.

2014-01-01

The capacity to predict and visualize all theoretically possible glycerophospholipid molecular identities present in lipidomic datasets is currently limited. To address this issue, we expanded the search-engine and compositional databases of the online Visualization and Phospholipid Identification (VaLID) bioinformatic tool to include the glycerophosphoinositol superfamily. VaLID v1.0.0 originally allowed exact and average mass libraries of 736,584 individual species from eight phospholipid classes: glycerophosphates, glyceropyrophosphates, glycerophosphocholines, glycerophosphoethanolamines, glycerophosphoglycerols, glycerophosphoglycerophosphates, glycerophosphoserines, and cytidine 5′-diphosphate 1,2-diacyl-sn-glycerols to be searched for any mass to charge value (with adjustable tolerance levels) under a variety of mass spectrometry conditions. Here, we describe an update that now includes all possible glycerophosphoinositols, glycerophosphoinositol monophosphates, glycerophosphoinositol bisphosphates, and glycerophosphoinositol trisphosphates. This update expands the total number of lipid species represented in the VaLID v2.0.0 database to 1,473,168 phospholipids. Each phospholipid can be generated in skeletal representation. A subset of species curated by the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics (CTPNL) team is provided as an array of high-resolution structures. VaLID is freely available and responds to all users through the CTPNL resources web site. PMID:24701584

Predicting glycerophosphoinositol identities in lipidomic datasets using VaLID (Visualization and Phospholipid Identification)--an online bioinformatic search engine.

PubMed

McDowell, Graeme S V; Blanchard, Alexandre P; Taylor, Graeme P; Figeys, Daniel; Fai, Stephen; Bennett, Steffany A L

2014-01-01

The capacity to predict and visualize all theoretically possible glycerophospholipid molecular identities present in lipidomic datasets is currently limited. To address this issue, we expanded the search-engine and compositional databases of the online Visualization and Phospholipid Identification (VaLID) bioinformatic tool to include the glycerophosphoinositol superfamily. VaLID v1.0.0 originally allowed exact and average mass libraries of 736,584 individual species from eight phospholipid classes: glycerophosphates, glyceropyrophosphates, glycerophosphocholines, glycerophosphoethanolamines, glycerophosphoglycerols, glycerophosphoglycerophosphates, glycerophosphoserines, and cytidine 5'-diphosphate 1,2-diacyl-sn-glycerols to be searched for any mass to charge value (with adjustable tolerance levels) under a variety of mass spectrometry conditions. Here, we describe an update that now includes all possible glycerophosphoinositols, glycerophosphoinositol monophosphates, glycerophosphoinositol bisphosphates, and glycerophosphoinositol trisphosphates. This update expands the total number of lipid species represented in the VaLID v2.0.0 database to 1,473,168 phospholipids. Each phospholipid can be generated in skeletal representation. A subset of species curated by the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics (CTPNL) team is provided as an array of high-resolution structures. VaLID is freely available and responds to all users through the CTPNL resources web site.

Clinical Manifestations and Outcome of Syphilitic Uveitis.

PubMed

Bollemeijer, Jan G; Wieringa, Wietse G; Missotten, Tom O A R; Meenken, Ina; ten Dam-van Loon, Ninette H; Rothova, Aniki; Los, Leonoor I

2016-02-01

To analyze visual outcome, effectiveness of various modes of antibiotic treatment, and prognostic factors in patients with serologically proven syphilitic uveitis. The clinical records of 85 patients (139 eyes) diagnosed with syphilitic uveitis between 1984 and 2013 at tertiary centers in The Netherlands were retrospectively analyzed. Mean age was 47 years (range, 27-73 years), 82.4% were male. HIV positivity was found in 28 (35.9%) patients; 13 were newly diagnosed. Most patients had pan (45.9%) or posterior (31.8%) uveitis. On average, logMAR visual acuity (VA) improved significantly from 0.55 at the start of syphilis treatment to 0.34 at 1 month and to 0.27 at 6 months follow-up. Most patients (86.7%) reached disease remission. No differences in efficacy between the various treatment regimens were found. A high logMAR VA at the start of syphilis treatment and a treatment delay of more than 12 weeks were prognostic for a high logMAR VA at 6 months follow-up. Chronicity was not related to any form of treatment, HIV status, or Venereal Disease Research Laboratory test outcome. In this large cohort of 85 patients with syphilitic uveitis, visual outcomes were favorable in the majority of cases. Visual outcome was dependent on VA at the start of syphilis treatment and treatment delay.

Neural Retinal Disorganization as a Robust Marker of Visual Acuity in Current and Resolved Diabetic Macular Edema

PubMed Central

Radwan, Salma H.; Soliman, Ahmed Z.; Lammer, Jan; Lin, Michael M.; Prager, Sonja G.; Silva, Paolo S.; Aiello, Lloyd Bryce; Aiello, Lloyd Paul

2015-01-01

Despite treatment advances, diabetic eye disease remains a leading cause of visual acuity (VA) loss worldwide. No methods to prospectively determine which patients will gain or lose vision exist, limiting individualized risk assessment and management. We investigated whether noninvasive, readily obtainable spectral domain optical coherence tomography parameters were correlated with VA in eyes with current or resolved center-involved diabetic macular edema (DME). Images were evaluated for disorganization of the retinal inner layers (DRIL), cysts, epiretinal membranes, microaneurysms, subretinal fluid, and outer layer disruption/reflectivity. DRIL affecting ≥50% of the 1-mm central retinal zone was associated with worse VA in all eyes, eyes with current edema, and eyes with resolved edema. Furthermore, early 4-month change in DRIL extent predicted VA change from baseline to 1 year. These data suggest that DRIL is a robust predictor of VA in eyes with present or previous DME and more highly correlated with VA than other widely used measures, such as retinal thickness. If further studies confirm DRIL as a predictive biomarker of future VA, physicians would gain a new tool of substantial clinical and investigative importance that could significantly change the approach to ophthalmic counseling and therapeutic management in patients with diabetes. PMID:25633419

The effects of a flexible visual acuity-driven ranibizumab treatment regimen in age-related macular degeneration: outcomes of a drug and disease model.

PubMed

Holz, Frank G; Korobelnik, Jean-François; Lanzetta, Paolo; Mitchell, Paul; Schmidt-Erfurth, Ursula; Wolf, Sebastian; Markabi, Sabri; Schmidli, Heinz; Weichselberger, Andreas

2010-01-01

Differences in treatment responses to ranibizumab injections observed within trials involving monthly (MARINA and ANCHOR studies) and quarterly (PIER study) treatment suggest that an individualized treatment regimen may be effective in neovascular age-related macular degeneration. In the present study, a drug and disease model was used to evaluate the impact of an individualized, flexible treatment regimen on disease progression. For visual acuity (VA), a model was developed on the 12-month data from ANCHOR, MARINA, and PIER. Data from untreated patients were used to model patient-specific disease progression in terms of VA loss. Data from treated patients from the period after the three initial injections were used to model the effect of predicted ranibizumab vitreous concentration on VA loss. The model was checked by comparing simulations of VA outcomes after monthly and quarterly injections during this period with trial data. A flexible VA-guided regimen (after the three initial injections) in which treatment is initiated by loss of >5 letters from best previously observed VA scores was simulated. Simulated monthly and quarterly VA-guided regimens showed good agreement with trial data. Simulation of VA-driven individualized treatment suggests that this regimen, on average, sustains the initial gains in VA seen in clinical trials at month 3. The model predicted that, on average, to maintain initial VA gains, an estimated 5.1 ranibizumab injections are needed during the 9 months after the three initial monthly injections, which amounts to a total of 8.1 injections during the first year. A flexible, individualized VA-guided regimen after the three initial injections may sustain vision improvement with ranibizumab and could improve cost-effectiveness and convenience and reduce drug administration-associated risks.

Correlation Between Vision and Cognitive Function in the Elderly

PubMed Central

Spierer, Oriel; Fischer, Naomi; Barak, Adiel; Belkin, Michael

2016-01-01

Abstract The correlation between vision and cognition is not fully understood. Visual impairment in the elderly has been associated with impaired cognitive function, dementia, and Alzheimer disease. The aim was to study the correlation between near visual acuity (VA), refraction, and cognitive state in an elderly population. Subjects ≥75 years were enrolled in this cross-sectional study. Refraction and near VA was tested. Cognitive function was evaluated with a version of the mini-mental state examination for the visually impaired (MMSE-blind). The eye with better VA and no cataract or refractive surgery was analyzed. One-hundred ninety subjects (81.6 ± 5.1 years, 69.5% female) were included. Good VA (≤J3) was associated with high MMSE-blind (>17) (OR = 3.18, 95% CI = 1.57–6.43, P = 0.001). This remained significant adjusting for sex, age, and years of education. Wearing reading glasses correlated significantly with high MMSE-blind after adjustment for sex and age (OR = 2.14, 95% CI = 1.16–3.97, P = 0.016), but reached borderline significance after adjustment for education. There was a trend toward correlation between myopia and better MMSE-blind (r = −0.123, P = 0.09, Pearson correlation). Good VA and wearing glasses seem to correlate with better cognitive function. Reading glasses can serve as a protective factor against cognitive deterioration associated with sensory (visual) deprivation in old age. The association between myopia and cognition requires further investigation. PMID:26817872

Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion.

PubMed

Balaratnasingam, Chandrakumar; Inoue, Maiko; Ahn, Seungjun; McCann, Jesse; Dhrami-Gavazi, Elona; Yannuzzi, Lawrence A; Freund, K Bailey

2016-11-01

To determine if the area of the foveal avascular zone (FAZ) is correlated with visual acuity (VA) in diabetic retinopathy (DR) and retinal vein occlusion (RVO). Cross-sectional study. Ninety-five eyes of 66 subjects with DR (65 eyes), branch retinal vein occlusion (19 eyes), and central retinal vein occlusion (11 eyes). Structural optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) and OCT angiography (OCTA; Avanti, Optovue RTVue XR) data from a single visit were analyzed. FAZ area, point thickness of central fovea, central 1-mm subfield thickness, the occurrence of intraretinal cysts, ellipsoid zone disruption, and disorganization of retinal inner layers (DRIL) length were measured. VA was also recorded. Correlations between FAZ area and VA were explored using regression models. Main outcome measure was VA. Mean age was 62.9±13.2 years. There was no difference in demographic and OCT-derived anatomic measurements between branch retinal vein occlusion and central retinal vein occlusion groups (all P ≥ 0.058); therefore, data from the 2 groups were pooled together to a single RVO group for further statistical comparisons. Univariate and multiple regression analysis showed that the area of the FAZ was significantly correlated with VA in DR and RVO (all P ≤ 0.003). The relationship between FAZ area and VA varied with age (P = 0.026) such that for a constant FAZ area, an increase in patient age was associated with poorer vision (rise in logarithm of the minimum angle of resolution visual acuity). Disruption of the ellipsoid zone was significantly correlated with VA in univariate and multiple regression analysis (both P < 0.001). Occurrence of intraretinal cysts, DRIL length, and lens status were significantly correlated with VA in the univariate regression analysis (P ≤ 0.018) but not the multiple regression analysis (P ≥ 0.210). Remaining variables evaluated in this study were not predictive of VA (all P ≥ 0.225). The area of the FAZ is significantly correlated with VA in DR and RVO and this relationship is modulated by patient age. Further study about FAZ area and VA correlations during the natural course of retinal vascular diseases and following treatment is warranted. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Vision Status in Older Adults: The Brazilian Amazon Region Eye Survey.

PubMed

Salomão, Solange R; Berezovsky, Adriana; Furtado, João M; Fernandes, Arthur G; Muñoz, Sergio; Cavascan, Nívea N; Cypel, Marcela C; Cunha, Cristina C; Vasconcelos, Galton C; Mitsuhiro, Márcia R K H; Sacai, Paula Y; Campos, Mauro; Morales, Paulo H A; Cohen, Marcos J; Cohen, Jacob M; Watanabe, Sung E S; Belfort, Rubens

2018-01-17

Older adults living in remote areas with limited access to health services are at higher risk to develop visual impairment and blindness. We conducted a population-based survey to determine the vision status in subjects 45 years of age and older from urban and rural areas of Parintins city, Brazilian Amazon Region. Participants underwent ophthalmic examination, including uncorrected (UCVA), presenting (PVA) and best-corrected visual acuity (BCVA). Vision status was described as lines of visual acuity (VA) impairment and lines of VA improvement from UCVA to BCVA and from PVA to BCVA in the better-seeing eye. A total of 2384 subjects were enumerated, 2041 (85.6%) were examined, with reliable VA measurements obtained from 2025 participants. Vision status in lines of VA impairment was (mean ± standard deviation): 3.44 ± 3.53 for UCVA, 2.85 ± 3.52 for PVA and 1.50 ± 3.51 for BCVA. Female gender, older age and lower education were associated with ≥6 lines of UCVA impairment. Lines of improvement ≥3 was found in 626 (30.9%) participants and associated with female gender and rural residency. In conclusion, a third of participants could have at least three lines of VA improvement with proper refraction. Strategies to improve access to eye care and affordable glasses are needed.

Factors associated with early detection of choroidal neovascularization in age-related macular degeneration in the clinic setting.

PubMed

Lichtinger, Alejandro; Caraza, Mauricio; Galbinur, Tural; Chowers, Itay

2012-06-01

Delayed diagnosis of choroidal neovas cularization (CNV) in age-related macular degeneration (AMD) adversely affects visual outcome. To identify factors associated with early detection of CNV in the clinic setting. Demographic and clinical data and lesion characteristics were retrospectively collected from 76 consecutive AMD patients who had a history of CNV in one eye and presented with CNV in the second eye. These data were evaluated for association with visual acuity (VA) at the time of presentation. Better VA was associated with a history of CNV in the fellow eye (P < 0.0001), adherence to follow-up every 4 months (P = 0.015), younger age (P = 0.03), smaller lesion (P < 0.0001), and non-subfoveal location (P = 0.048). VA of the fellow eye did not correlate with VA at presentation with CNV. These data suggest that patients' experience of CNV, regardless of VA, facilitates early diagnosis in the fellow eye. Adherence to follow-up in the routine clinic setting also facilitates early detection of CNV.

Reliability of fully automated versus visually controlled pre- and post-processing of resting-state EEG.

PubMed

Hatz, F; Hardmeier, M; Bousleiman, H; Rüegg, S; Schindler, C; Fuhr, P

2015-02-01

To compare the reliability of a newly developed Matlab® toolbox for the fully automated, pre- and post-processing of resting state EEG (automated analysis, AA) with the reliability of analysis involving visually controlled pre- and post-processing (VA). 34 healthy volunteers (age: median 38.2 (20-49), 82% female) had three consecutive 256-channel resting-state EEG at one year intervals. Results of frequency analysis of AA and VA were compared with Pearson correlation coefficients, and reliability over time was assessed with intraclass correlation coefficients (ICC). Mean correlation coefficient between AA and VA was 0.94±0.07, mean ICC for AA 0.83±0.05 and for VA 0.84±0.07. AA and VA yield very similar results for spectral EEG analysis and are equally reliable. AA is less time-consuming, completely standardized, and independent of raters and their training. Automated processing of EEG facilitates workflow in quantitative EEG analysis. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Visual acuity and refractive errors in a suburban Danish population: Inter99 Eye Study.

PubMed

Kessel, Line; Hougaard, Jesper Leth; Mortensen, Claus; Jørgensen, Torben; Lund-Andersen, Henrik; Larsen, Michael

2004-02-01

The present study was performed as part of an epidemiological study, the Inter99 Eye Study. The aim of the study was to describe refractive errors and visual acuity (VA) in a suburban Danish population. The Inter99 Eye Study comprised 970 subjects aged 30-60 years and included a random control group as well as groups at high risk for ischaemic heart disease and diabetes mellitus. The present study presents VAs and refractive data from the control group (n = 502). All subjects completed a detailed questionnaire and underwent a standardized general physical and ophthalmic examination including determination of best corrected VA and subjective refractioning. Visual acuity

Fluctuation in visual acuity during soft toric contact lens wear.

PubMed

Chamberlain, Paul; Morgan, Philip B; Moody, Kurt J; Maldonado-Codina, Carole

2011-04-01

To quantify changes in visual acuity (VA) with soft toric contact lenses as a result of lens movement and/or rotational instability caused by versional eye movements. A novel chart for vision assessment at near (40 cm) for soft toric contact lenses (VANT chart),consisting of a central, color-coded logMAR panel and eight peripheral letter targets set on a white background measuring 60 × 40 cm was constructed. In the developmental phase of the work, 10 subjects (20 eyes) wore 2 toric lenses in random order, and the impact of rapid and delayed eye versions in 8 directions of gaze on VANT acuity was investigated. In phase 2, 35 subjects (68 eyes) wore 4 toric lenses in random order, and a streamlined clinical protocol using the VANT chart was implemented. Standard assessments of toric lens fit and distance VA were also performed. Testing in the first phase showed no difference for change in VA for rapid vs. delayed version movements, (p = 0.17) but acuity reduction was greater for diagonal compared with horizontal/vertical versions (p = 0.06). As such, testing in phase 2 proceeded using rapid, diagonal versions only. In this second phase, there were differences for low-contrast distance VA measures between lens types (p = 0.02) and for both VANT baseline acuity (p = 0.03) and postversion acuity (p = 0.04), but no differences were found between lenses for magnitude of vision loss (p = 0.91), which was about one line. No relationship was established between the magnitude of vision loss and measured rotational stability (p = 0.75). This work has demonstrated that conventional approaches to measuring VA do not fully replicate the "real world" experience of soft toric lens wearers. The VANT chart has shown that VA is reduced immediately after versional eye movements and suggests that more dynamic methods of assessing visual performance should be considered for soft toric contact lens wearers, especially given the apparent inability of lens stability measurements to predict visual performance.

Dry-eye screening by using a functional visual acuity measurement system: the Osaka Study.

PubMed

Kaido, Minako; Uchino, Miki; Yokoi, Norihiko; Uchino, Yuichi; Dogru, Murat; Kawashima, Motoko; Komuro, Aoi; Sonomura, Yukiko; Kato, Hiroaki; Kinoshita, Shigeru; Tsubota, Kazuo

2014-05-06

We determined whether functional visual acuity (VA) parameters and a dry eyes (DEs) symptoms questionnaire could predict DEs in a population of visual terminal display (VDT) users. This prospective study included 491 VDT users from the Osaka Study. Subjects with definite DE, diagnosed with the presence of DE symptoms, tear abnormality (Schirmer test ≤ 5 mm or tear breakup time [TBUT] ≤ 5 seconds), and conjunctivocorneal epithelial damage (total staining score of ≥3 points), or probable DE, diagnosed with the presence of two of them, were assigned to a DE group, and the remainder to a non-DE group. Functional VA was assessed, and DE questionnaires were administered. We assessed whether univariate and discriminant analyses could determine to which group a subject belonged. Sensitivity and specificity were assessed. Of 491 subjects, 320 and 171 were assigned to the DE and non-DE groups, respectively. No significant differences were observed between DE and non-DE groups in Schirmer test value and epithelial damage, but TBUT value (3.1 ± 1.5 vs. 5.9 ± 3.0 seconds). The sensitivity and specificity of single test using functional VA parameters were 59% and 49% in functional VA, 60% and 50% in visual maintenance ratio, and 83% and 30% in frequency of blinking, respectively. According to a discriminant analysis using a combination of functional VA parameters and a DE questionnaire, six variables were selected for the discriminant equation, of which area under the curve (AUC) was 0.735. Sensitivity and specificity of diagnoses predicted by the discriminant equation were 85.9% and 45.6%, respectively. The discriminant equation obtained using functional VA measurement combined with a symptoms questionnaire may suggest the possibility for the first step screening of DE with unstable tear film. Since the questionnaire has an overall poor sensitivity and specificity, further amelioration may be necessary for the actual utilization of this screening tool. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Dual-Image Videoangiography During Intracranial Microvascular Surgery.

PubMed

Feletti, Alberto; Wang, Xiangdong; Tanaka, Riki; Yamada, Yasuhiro; Suyama, Daisuke; Kawase, Tsukasa; Sano, Hirotoshi; Kato, Yoko

2017-03-01

Indocyanine green videoangiography (ICG-VA) is a valuable tool to assess vessel and aneurysm patency during neurovascular surgical procedures. However, ICG-VA highlights vascular structures, which appear white over a black background. Anatomic relationships are sometimes difficult to understand at first glance. Dual-image videoangiography (DIVA) enables simultaneous visualization of light and near-infrared fluorescence images of ICG-VA. The DIVA system was mounted on an OPMI Pentero Flow 800 intraoperative microscope. DIVA was used during microsurgical procedures on 5 patients who were operated for aneurysm clipping and superficial temporal artery-middle cerebral artery bypass. DIVA provides real-time simultaneous visualization of aneurysm and vessels and surrounding structures including brain, nerves, and surgical clips. Although visual contrast between vessels and background is higher with standard black-and-white imaging, DIVA makes it easier to understand anatomic relationships between intracranial structures. DIVA also provides better vision of the depth of field. DIVA has the potential to become a widely used intraoperative tool to check patency of intracranial vessels. It should be considered as an adjunct to standard ICG-VA for better understanding of vascular anatomy in relation to surrounding structures and can have an impact on decision making during surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

The Top 10 Challenges in Extreme-Scale Visual Analytics

PubMed Central

Wong, Pak Chung; Shen, Han-Wei; Johnson, Christopher R.; Chen, Chaomei; Ross, Robert B.

2013-01-01

In this issue of CG&A, researchers share their R&D findings and results on applying visual analytics (VA) to extreme-scale data. Having surveyed these articles and other R&D in this field, we’ve identified what we consider the top challenges of extreme-scale VA. To cater to the magazine’s diverse readership, our discussion evaluates challenges in all areas of the field, including algorithms, hardware, software, engineering, and social issues. PMID:24489426

Visual Performance of a Quadrifocal (Trifocal) Intraocular Lens Following Removal of the Crystalline Lens.

PubMed

Kohnen, Thomas; Herzog, Michael; Hemkeppler, Eva; Schönbrunn, Sabrina; De Lorenzo, Nina; Petermann, Kerstin; Böhm, Myriam

2017-12-01

To evaluate visual performance after implantation of a quadrifocal intraocular lens (IOL). Setting: Department of Ophthalmology, Goethe University, Frankfurt, Germany. Twenty-seven patients (54 eyes) received bilateral implantation of the PanOptix IOL (AcrySof IQ PanOptixTM; Alcon Research, Fort Worth, Texas, USA) pre-enrollment. Exclusion criteria were previous ocular surgeries, corneal astigmatism of >1.5 diopter (D), ocular pathologies, or corneal abnormalities. Intervention or Observational Procedure(s): Postoperative examination at 3 months including manifest refraction; uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) in 4 m, 80 cm, 60 cm, and 40 cm slit-lamp examination; defocus testing; contrast sensitivity (CS) under photopic and mesopic conditions; and a questionnaire on subjective quality of vision, optical phenomena, and spectacle independence was performed. At 3 months postoperatively, UCVA and DCVA in 4 m, 80 cm, 60 cm, and 40 cm (logMAR), defocus curves, CS, and quality-of-vision questionnaire results. Mean spherical equivalent was -0.04 ± 0.321 D 3 months postoperatively. Binocular UCVA at distance, intermediate (80 cm, 60 cm), and near was 0.00 ± 0.094 logMAR, 0.09 ± 0.107 logMAR, 0.00 ± 0.111 logMAR, and 0.01 ± 0.087 logMAR, respectively. Binocular defocus curve showed peaks with best visual acuity (VA) at 0.00 D (-0.07 logMAR) and -2.00 D (-0.02 logMAR). Visual performance of the PanOptix IOL showed good VA at all distances; particularly good intermediate VA (logMAR > 0.1), with best VA at 60 cm; and high patient satisfaction and spectacle independence 3 months postoperatively. Copyright © 2017 Elsevier Inc. All rights reserved.

The first rapid assessment of avoidable blindness (RAAB) in Thailand.

PubMed

Isipradit, Saichin; Sirimaharaj, Maytinee; Charukamnoetkanok, Puwat; Thonginnetra, Oraorn; Wongsawad, Warapat; Sathornsumetee, Busaba; Somboonthanakij, Sudawadee; Soomsawasdi, Piriya; Jitawatanarat, Umapond; Taweebanjongsin, Wongsiri; Arayangkoon, Eakkachai; Arame, Punyawee; Kobkoonthon, Chinsuchee; Pangputhipong, Pannet

2014-01-01

The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5-0.8), 1.3% (95% CI: 1.0-1.6), 12.6% (95% CI: 10.8-14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

[Retinal detachment associated with morning glory syndrome].

PubMed

Cañete Campos, C; Gili Manzanaro, P; Yangüela Rodilla, J; Martín Rodrigo, J C

2011-09-01

A twenty three year old woman was diagnosed of a morning glory papillary anomaly, then with normal visual acuity (VA). Nine years later, the VA decreased to 0.4, secondary to a serous macular detachment, confirmed by optical coherence tomography (OCT). After treatment with C2F6 gas injection, positioning, and peripapillary laser, the VA improved to 0.7 and the foveolar area reattached. The morning glory Syndrome usually has an early diagnosis due to poor visual acuity. Thirty eight percent of the cases have retinal detachment. We show an unusual case of morning glory syndrome with a serous detachment, successfully treated with gas and laser. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Graph theoretical analysis of EEG effective connectivity in vascular dementia patients during a visual oddball task.

PubMed

Wang, Chao; Xu, Jin; Zhao, Songzhen; Lou, Wutao

2016-01-01

The study was dedicated to investigating the change in information processing in brain networks of vascular dementia (VaD) patients during the process of decision making. EEG was recorded from 18 VaD patients and 19 healthy controls when subjects were performing a visual oddball task. The whole task was divided into several stages by using global field power analysis. In the stage related to the decision-making process, graph theoretical analysis was applied to the binary directed network derived from EEG signals at nine electrodes in the frontal, central, and parietal regions in δ (0.5-3.5Hz), θ (4-7Hz), α1 (8-10Hz), α2 (11-13Hz), and β (14-30Hz) frequency bands based on directed transfer function. A weakened outgoing information flow, a decrease in out-degree, and an increase in in-degree were found in the parietal region in VaD patients, compared to healthy controls. In VaD patients, the parietal region may also lose its hub status in brain networks. In addition, the clustering coefficient was significantly lower in VaD patients. Impairment might be present in the parietal region or its connections with other regions, and it may serve as one of the causes for cognitive decline in VaD patients. The brain networks of VaD patients were significantly altered toward random networks. The present study extended our understanding of VaD from the perspective of brain functional networks, and it provided possible interpretations for cognitive deficits in VaD patients. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Evaluation of Visual Acuity Measurements after Autorefraction versus Manual Refraction in Eyes with and without Diabetic Macular Edema

PubMed Central

Sun, Jennifer K.; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W.; Andreoli, Christopher M.; Edwards, Paul A.; Glassman, Adam R.; Pavlica, Michael R.

2012-01-01

Objective To compare visual acuity (VA) scores after autorefraction versus research protocol manual refraction in eyes of patients with diabetes and a wide range of VA. Methods Electronic Early Treatment Diabetic Retinopathy Study (E-ETDRS) VA Test© letter score (EVA) was measured after autorefraction (AR-EVA) and after Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction (MR-EVA). Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA utilizing an identical manual refraction (MR-EVAsupl) was performed to determine test-retest variability. Results In 878 eyes of 456 study participants, median MR-EVA was 74 (Snellen equivalent approximately 20/32). Spherical equivalent was often similar for manual and autorefraction (median difference: 0.00, 5th and 95th percentiles −1.75 to +1.13 Diopters). However, on average, MR-EVA results were slightly better than AR-EVA results across the entire VA range. Furthermore, variability between AR-EVA and MR-EVA was substantially greater than the test-retest variability of MR-EVA (P<0.001). Variability of differences was highly dependent on autorefractor model. Conclusions Across a wide range of VA at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models comparing most favorably to manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA. PMID:22159173

Influence of different types of astigmatism on visual acuity.

PubMed

Remón, Laura; Monsoriu, Juan A; Furlan, Walter D

To investigate the change in visual acuity (VA) produced by different types of astigmatism (on the basis of the refractive power and position of the principal meridians) on normal accommodating eyes. The lens induced method was employed to simulate a set of 28 astigmatic blur conditions on different healthy emmetropic eyes. Additionally, 24 values of spherical defocus were also simulated on the same eyes for comparison. VA was measured in each case and the results, expressed in logMAR units, were represented against of the modulus of the dioptric power vector (blur strength). LogMAR VA varies in a linear fashion with increasing astigmatic blur, being the slope of the line dependent on the accommodative demand in each type of astigmatism. However, in each case, we found no statistically significant differences between the three axes investigated (0°, 45°, 90°). Non-statistically significant differences were found either for the VA achieved with spherical myopic defocus (MD) and mixed astigmatism (MA). VA with simple hyperopic astigmatism (SHA) was higher than with simple myopic astigmatism (SMA), however, in this case non conclusive results were obtained in terms of statistical significance. The VA achieved with imposed compound hyperopic astigmatism (CHA) was highly influenced by the eye's accommodative response. VA is correlated with the blur strength in a different way for each type of astigmatism, depending on the accommodative demand. VA is better when one of the focal lines lie on the retina irrespective of the axis orientation; accommodation favors this situation. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

A neuroergonomic quasi-experiment: Predictors of situation awareness and display usability while performing complex tasks

NASA Astrophysics Data System (ADS)

Harbour, Steven D.; Christensen, James C.

2015-05-01

Situation awareness (SA) is the ability and capacity to perceive information and act on it acceptably. Head Up Display (HUD) versus Head Down Display (HDD) manipulation induced variation in task difficulty. HUD and HDD cockpit displays or display designs promoted or impaired SA. The quantitative research presented in this paper examines basic neurocognitive factors in order to identify their specific contributions to the formation of SA, while studying display usability and the effects on SA. Visual attentiveness (Va), perceptiveness (Vp), and spatial working memory (Vswm) were assessed as predictors of SA under varying task difficulty. The study participants were 19 tactical airlift pilots, selected from the Ohio Air National Guard. Neurocognitive tests were administered to the participants prior to flight. In-flight SA was objectively and subjectively assessed for 24 flights. At the completion of this field experiment, the data were analyzed and the tests were statistically significant for the three predictor visual abilities Vp, Va, and Vswm as task difficulty was varied, F(3,11) = 8.125, p = .008. In addition, multiple regression analyses revealed that the visual abilities together predicted a majority of the variance in SA, R2 = 0.753, p = .008. As validated and verified by ECG and EEG data, the HUD yielded a full ability and capacity to anticipate and accommodate trends were as the HDD yielded a saturated ability to anticipate and accommodate trends. Post-hoc tests revealed a Cohen's f2 = 3.05 yielding statistical power to be 0.98. This work results in a significant contribution to the field by providing an improved understanding of SA and path to safer travel for society worldwide. PA 88ABW-2015-1282.

Trifocal intraocular lenses: a comparison of the visual performance and quality of vision provided by two different lens designs.

PubMed

Gundersen, Kjell G; Potvin, Rick

2017-01-01

To compare two different diffractive trifocal intraocular lens (IOL) designs, evaluating longer-term refractive outcomes, visual acuity (VA) at various distances, low contrast VA and quality of vision. Patients with binocularly implanted trifocal IOLs of two different designs (FineVision [FV] and Panoptix [PX]) were evaluated 6 months to 2 years after surgery. Best distance-corrected and uncorrected VA were tested at distance (4 m), intermediate (80 and 60 cm) and near (40 cm). A binocular defocus curve was collected with the subject's best distance correction in place. The preferred reading distance was determined along with the VA at that distance. Low contrast VA at distance was also measured. Quality of vision was measured with the National Eye Institute Visual Function Questionnaire near subset and the Quality of Vision questionnaire. Thirty subjects in each group were successfully recruited. The binocular defocus curves differed only at vergences of -1.0 D (FV better, P =0.02), -1.5 and -2.00 D (PX better, P <0.01 for both). Best distance-corrected and uncorrected binocular vision were significantly better for the PX lens at 60 cm ( P <0.01) with no significant differences at other distances. The preferred reading distance was between 42 and 43 cm for both lenses, with the VA at the preferred reading distance slightly better with the PX lens ( P =0.04). There were no statistically significant differences by lens for low contrast VA ( P =0.1) or for quality of vision measures ( P >0.3). Both trifocal lenses provided excellent distance, intermediate and near vision, but several measures indicated that the PX lens provided better intermediate vision at 60 cm. This may be important to users of tablets and other handheld devices. Quality of vision appeared similar between the two lens designs.

38 CFR 17.628 - Availability of VIOMPSP scholarships.

Code of Federal Regulations, 2014 CFR

2014-07-01

... scholarships. 17.628 Section 17.628 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Visual Impairment and Orientation and Mobility Professional Scholarship Program § 17.628 Availability of VIOMPSP scholarships. VA will make awards under the VIOMPSP only when VA determines it is...

Visual performance after the implantation of a new trifocal intraocular lens

PubMed Central

Vryghem, Jérôme C; Heireman, Steven

2013-01-01

Purpose To evaluate the subjective and objective visual results after the implantation of a new trifocal diffractive intraocular lens. Methods A new trifocal diffractive intraocular lens was designed combining two superimposed diffractive profiles: one with +1.75 diopters (D) addition for intermediate vision and the other with +3.50 D addition for near vision. Fifty eyes of 25 patients that were operated on by one surgeon are included in this study. The uncorrected and best distance-corrected monocular and binocular, near, intermediate, and distance visual acuities, contrast sensitivity, and defocus curves were measured 6 months postoperatively. In addition to the standard clinical follow-up, a questionnaire evaluating individual satisfaction and quality of life was submitted to the patients. Results The mean age of patients at the time of surgery was 70 ± 10 years. The mean uncorrected and corrected monocular distance visual acuity (VA) were LogMAR 0.06 ± 0.10 and LogMAR 0.00 ± 0.08, respectively. The outcomes for the binocular uncorrected distance visual acuity were almost the same (LogMAR −0.04 ± 0.09). LogMAR −010 ± 0.15 and 0.02 ± 0.06 were measured for the binocular uncorrected intermediate and near VA, respectively. The distance-corrected visual acuity was maintained in mesopic conditions. The contrast sensitivity was similar to that obtained after implantation of a bifocal intraocular lens and did not decrease in mesopic conditions. The binocular defocus curve confirms good VA even in the intermediate distance range, with a moderate decrease of less than LogMAR 0.2 at −1.5 D, with respect to the best distance VA at 0 D defocus. Patient satisfaction was high. No discrepancy between the objective and subjective outcomes was evidenced. Conclusion The introduction of a third focus in diffractive multifocal intraocular lenses improves the intermediate vision with minimal visual discomfort for the patient. PMID:24124348

Comparison of visual status of Iranian military and commercial drivers.

PubMed

Ghasemi, Mohammad; Hoseini Yazdi, Seyed Hosein; Heravian, Javad; Jafarzadehpur, Ebrahim; Rezaee, Maryam

2015-04-01

There is no legal requirement for Iranian military truck drivers to undergo regular visual checkups as compared to commercial truck drivers. This study aimed to evaluate the impact of drivers' visual checkups by comparing the visual function of Iranian military and commercial truck drivers. In this comparative cross-sectional study, two hundred military and 200 commercial truck drivers were recruited and their Visual Acuity (VA), Visual Field (VF), color vision and Contrast Sensitivity (CS) were assessed and compared using the Snellen chart, confrontation screening method, D15 test and Pelli-Robson letter chart, respectively. A questionnaire regarding driving exposure and history of motor-vehicle crashes (MVCs) was also filled by drivers. Results were analyzed using an independent samples t-test, one-way ANOVA (assessing difference in number of MVCs across different age groups), chi-square test and Pearson correlation at statistical significance level of P < 0.05. Mean age was 41.6 ± 9.2 for the military truck drivers and 43.4 ± 10.9 for commercial truck drivers (P > 0.05). No significant difference between military and commercial drivers was found in terms of driving experience, number of MVCs, binocular VA, frequency of color vision defects and CS scores. In contrast, the last ocular examination was significantly earlier in military drivers than commercial drivers (P < 0.001). In addition, 4% of military drivers did not meet the national standards to drive as opposed to 2% of commercial drivers. There was a significant but weak correlation between binocular VA and age (r = 0.175, P < 0.001). However, CS showed a significantly moderate correlation with age (r = -0.488, P < 0.001). The absence of legal requirement for regular eye examination in military drivers caused the incompetent drivers to be missed in contrast to commercial drivers. The need for scientific revision of VA standard for Iranian drivers is also discussed. The CS measurement in visual checkups of older drivers deserves to be investigated more thoroughly.

Quality of life and visual function in Nigeria: findings from the National Survey of Blindness and Visual Impairment.

PubMed

Tran, Hang My; Mahdi, Abdull M; Sivasubramaniam, Selvaraj; Gudlavalleti, Murthy V S; Gilbert, Clare E; Shah, Shaheen P; Ezelum, C C; Abubakar, Tafida; Bankole, Olufunmilayo O

2011-12-01

To assess associations of visual function (VF) and quality of life (QOL) by visual acuity (VA), causes of blindness and types of cataract procedures in Nigeria. Multi-stage stratified cluster random sampling was used to identify a nationally representative sample of persons aged ≥ 40 years. VF/QOL questionnaires were administered to participants with VA <6/60 in one or both eyes and/or Mehra-Minassian cataract grade 2B or 3 in one or both eyes and a random sample of those with bilateral VA ≥ 6/12. VF/QOL questionnaires were administered to 2076 participants. Spearman's rank correlation showed a strong correlation between decreasing VA and VF/QOL scores (p<0.0001) with greatest impact on social (p<0.0001) and mobility-related activities (p<0.0001). People who were blind due to glaucoma had lower VF and QOL scores than those who were blind due to cataract. Mean VF and QOL scores were lower after couching compared with conventional cataract surgery (mean VF score=51.0 vs 63.0 and mean QOL score=71.3 vs 79.3). Finally, VF and QOL scores were lower among populations with specific characteristics. Populations with the following characteristics should be targeted to improve VF and QOL: people who are blind, older people, women, manual labourers, people living in rural areas, those living in the northern geopolitical zones, those practising Islamic and Traditionalism faith, those not currently married and those who have undergone couching.

Assessment of quality of life in patients with visual impairments using a new visual function questionnaire: the VFQ-J11

PubMed Central

Nakano, Tadashi; Kawashima, Motoko; Hiratsuka, Yoshimune; Tamura, Hiroshi; Ono, Koichi; Murakami, Akira; Tsubota, Kazuo; Yamada, Masakazu

2016-01-01

Background The purpose of the present study was to assess the vision-related quality of life (QOL) of visually impaired patients using the Japanese 11-item National Eye Institute Visual Function Questionnaire (VFQ-J11). Comparisons with the 25-item version (VFQ-25) and the EuroQoL Index using a large group of patients with various degrees of impairments and various causative diseases were performed. Methods A total of 232 visually impaired Japanese patients were recruited from six ophthalmology departments in Japan. Information on ophthalmic findings and patient backgrounds was collected, and information on QOL and utility assessments was collected from the patients by means of survey questionnaires. Results The average age of patients was 69.6±14.3 years. Both the vision-related QOL scores (VFQ-25 composite and VFQ-J11) were significantly associated with better and worse visual acuity (VA) in visually impaired subjects (all P<0.01). VFQ-J11 was comparable to VFQ-25 regardless of causative diseases. VFQ-25 composite and the VFQ-J11 scores were concurrently associated with a range of systemic medical disorders. EuroQoL Index had a significant association with better eye VA (P<0.01), but not with worse eye VA, or any systemic disorders. Conclusion VFQ-J11 provides valid data on vision-related QOL and is less of a burden for patients with vision problems. PMID:27784982

Visual abilities of students with severe developmental delay in special needs education - a vision screening project in Northern Jutland, Denmark.

PubMed

Welinder, Lotte G; Baggesen, Kirsten L

2012-12-01

To investigate the visual abilities of students with severe developmental delay (DD) age 6-8 starting in special needs education. Between 1 January 2000 and 31 December 2008, we screened all students with severe DD starting in special needs schools in Northern Jutland, Denmark for vision. All students with visual acuities ≤6/12 were refractioned and examined by an ophthalmologist. Of 502 students, 56 (11%) had visual impairment (VI) [visual acuity (VA) ≤ 6/18], of which 21 had been previously undiagnosed. Legal blindness was found in 15 students (3%), of whom three had previously been undiagnosed. Students tested with preferential looking systems (N = 78) had significantly lower visual acuities [VA (decimal) = 0.55] than students tested with ortho types [VA (decimal) = 0.91] and had problems participating in the colour and form tests, possibly due to cerebral VI. The number of students with decreased vision identified by screening decreased significantly during the study period (r = 0.724, p = 0.028). The number of students needed to be screened to find one student with VI was 24 and to identify legal blindness 181 needed to be screened. Visual impairment is a common condition in students with severe DD. Despite increased awareness of VI in the school and health care system, we continued to find a considerable number of students with hitherto undiagnosed decreased vision. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

Secular trends of reduced visual acuity from 1985 to 2010 and disease burden projection for 2020 and 2030 among primary and secondary school students in China.

PubMed

Sun, Hong-Peng; Li, Ang; Xu, Yong; Pan, Chen-Wei

2015-03-01

Understanding the burden and trends of reduced visual acuity (VA), a proxy measure for myopia, is essential to guide future health care and clinical management in China. To describe the secular trends from 1985 to 2010, correlate the prevalence of reduced VA among children and adolescents with population density, and project the burden of reduced VA in China in 2020 and 2030. The National Survey on the Constitution and Health of Chinese Students conducted from 1985 to 2010, including 6 repeated surveys with a 3-stage clustering sampling strategy. Mainland China. Primary and secondary school students 7 to 18 years of age were randomly selected from 30 of 31 mainland provinces, excluding Tibet. Unaided distance VA was measured using a retroilluminated logMAR chart with tumbling-E optotypes. World Population Prospects data (the 2012 revision from the Population Division of the Department of Economic and Social Affairs of the United Nations) were used to project the number of people affected by reduced VA in 2020 and 2030. This analysis included 725 423, 142 655, 206 601, 219 663, 234 377, and 215 308 students in 1985, 1991, 1995, 2000, 2005, and 2010, respectively. The overall prevalence of reduced VA was 28.6% (95% CI, 28.4%-28.7%) in 1985, 38.6% (95% CI, 38.3%-38.8%) in 1991, 41.0% (95% CI, 40.8%-41.2%) in 1995, 38.5% (95% CI, 38.3%-38.7%) in 2000, 49.5% (95% CI, 49.3%-49.7%) in 2005, and 56.8% (95% CI, 56.6%-57.0%) in 2010. Girls were more susceptible than boys to having reduced VA (odds ratio, 1.38 [95% CI, 1.35-1.40]), and reduced VA was more prevalent in urban areas than in rural areas (odds ratio, 1.84 [95% CI, 1.81-1.87]). Reduced VA was not significantly associated with population density (P = .11). The projected numbers of cases with reduced VA are about 152.4 million (95% CI, 151.9-152.9 million) in 2020, increasing to 180.4 million (95% CI, 179.8-181.2 million) in 2030 among students who are 7 to 18 years of age in mainland China. There was an increasing trend of reduced VA in both urban and rural areas from 1985 to 2010 in China. Although reduced unaided distance VA is not equal to visual impairment, these summary data are helpful in designing strategies for eye care and health services in China, which may also have public health implications for other developing countries whose economies are growing rapidly.

Driving habits in older patients with central vision loss.

PubMed

Sengupta, Sabyasachi; van Landingham, Suzanne W; Solomon, Sharon D; Do, Diana V; Friedman, David S; Ramulu, Pradeep Y

2014-03-01

To determine if central visual loss is associated with driving cessation, driving restriction, or other-driver preference. Cross-sectional study. Sixty-four subjects with bilateral visual loss (<20/32 in better eye) or severe unilateral visual loss (<20/200) from age-related macular degeneration (AMD) and 58 normally sighted controls between 60 and 80 years of age. Participants self-reported driving habits. Other-driver preference was defined as preferring that another drive when there is more than 1 driver in the car. Subjects reporting 2 or more driving limitations were considered to have restricted their driving. Self-reported driving cessation, other-driver preference, and driving restriction. Age-related macular degeneration subjects were older (74.7 vs. 69.7 years), had worse visual acuity (VA; mean better-eye VA, 0.43 vs. 0.08 logarithm of minimum angle of resolution [logMAR]) and contrast sensitivity (CS; 1.4 vs. 1.9 log units of CS [logCS]), and were more likely to be white when compared with controls (P<0.001 for all). Drivers with AMD-related vision loss were more likely to avoid driving over longer distances, beyond 1 hour, at night, and in unfamiliar conditions (P < 0.05 for all). In multivariate models, driving cessation was associated with worse better-eye VA (odds ratio [OR], 1.5 per 1-line decrement in VA; P<0.001) and worse binocular CS (OR, 1.36 per 0.1 logCS increment; P = 0.005); however, AMD group status was not associated with driving cessation (OR, 1.9; P = 0.35). Factors predicting driving restriction were AMD (OR, 9.0; P = 0.004), worse vision (OR, 2.5 per line of VA loss; P<0.001), lower CS (OR, 2.2 per 0.1-logCS increment; P<0.001), and female gender (OR, 27.9; P = 0.002). Other-driver preference was more common with worse vision (OR, 1.6 per 0.1-logMAR increment; P = 0.003), female gender (OR, 4.5; P = 0.02), and being married (OR, 3.8; P = 0.04). Most patients with AMD-related central vision loss continue to drive, but demonstrate significant driving restrictions, especially with more severe VA and CS loss. Future work should determine which driving adaptations the visually impaired best balance safety and independence. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Myopic astigmatism correction: comparison of a Toric Implantable Collamer Lens and a bioptics technique by an adaptive optics visual simulator.

PubMed

Pérez-Vives, Cari; Domínguez-Vicent, Alberto; Madrid-Costa, David; Ferrer-Blasco, Teresa; Montés-Micó, Robert

2013-03-01

To compare the optical and visual quality of a simulated Toric Implantable Collamer Lens (TICL) and a bioptics technique to treat high myopic astigmatism. An adaptive optics visual simulator was used to simulate the vision after TICL implantation and a bioptics procedure from the wavefront aberration pattern for moderate and high-myopic astigmatism. Visual acuity (VA) at different contrasts and contrast sensitivity (CS) at 10, 20 and 25 cycles degree(-1) were measured for 3 and 5-mm pupils. Modulation Transfer Function (MTF) and Point Spread Function (PSF) were calculated for a 5-mm pupil. At a 3-mm pupil we only found statistically significant differences in VA between the two simulated surgeries at low-contrast for moderate- and high-myopic astigmatism (p < 0.05). Statistically significant differences were found in CS at 3-mm pupil between both procedures at the highest spatial frequency for moderate-myopic astigmatism and at all frequencies for high-myopic astigmatism (p < 0.05). At a 5-mm pupil we found statistically significant differences in VA and CS between both simulated surgeries at all contrasts and frequencies evaluated for both groups (p < 0.05). In all cases VA and CS were better with the TICL than with the bioptics technique. MTFs for the bioptics technique were worse than those computed for the TICL. The TICL showed less spread out of the PSF than the bioptics procedure. Simulated TICL and bioptics procedures provided good optical and visual quality, although TICL implantation provided slightly better outcomes than the bioptics procedure, especially when the pupil diameter was increased. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Visual Outcomes, Quality of Vision, and Quality of Life of Diffractive Multifocal Intraocular Lens Implantation after Myopic Laser In Situ Keratomileusis: A Prospective, Observational Case Series

PubMed Central

2017-01-01

Purpose. To report visual performance and quality of life after implantation of a bifocal diffractive multifocal intraocular lens (MIOL) in postmyopic laser in situ keratomileusis (LASIK) patients. Methods. Prospective, observational case series. Patients with prior myopic LASIK who had implantation of Tecnis ZMA00/ZMB00 MIOL (Abbott Medical Optics) at Hong Kong Sanatorium and Hospital were included. Postoperative examinations included monocular and binocular distance, intermediate and near visual acuity (VA), and contrast sensitivity; visual symptoms (0–5); satisfaction (1–5); spectacle independence rate; and quality of life. Results. Twenty-three patients (27 eyes) were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate, and near were 0.13 ± 0.15 (standard deviation), 0.22 ± 0.15, and 0.16 ± 0.15, respectively. Corresponding mean values for binocular uncorrected VA were 0.00 ± 0.10, 0.08 ± 0.13, and 0.13 ± 0.10, respectively. No eyes lost >1 line of corrected distance VA. Contrast sensitivity at different spatial frequencies between operated and unoperated eyes did not differ significantly (all P > 0.05). Mean score for halos, night glare, starbursts, and satisfaction were 1.46 ± 1.62, 1.85 ± 1.69, 0.78 ± 1.31, and 3.50 ± 1.02, respectively. Eighteen patients (78%) reported complete spectacle independence. Mean composite score of the quality-of-life questionnaire was 90.31 ± 8.50 out of 100. Conclusions. Implantation of the MIOL after myopic LASIK was safe and achieved good visual performance. PMID:28133543

Visual Outcomes, Quality of Vision, and Quality of Life of Diffractive Multifocal Intraocular Lens Implantation after Myopic Laser In Situ Keratomileusis: A Prospective, Observational Case Series.

PubMed

Chang, John S M; Ng, Jack C M; Chan, Vincent K C; Law, Antony K P

2017-01-01

Purpose . To report visual performance and quality of life after implantation of a bifocal diffractive multifocal intraocular lens (MIOL) in postmyopic laser in situ keratomileusis (LASIK) patients. Methods . Prospective, observational case series. Patients with prior myopic LASIK who had implantation of Tecnis ZMA00/ZMB00 MIOL (Abbott Medical Optics) at Hong Kong Sanatorium and Hospital were included. Postoperative examinations included monocular and binocular distance, intermediate and near visual acuity (VA), and contrast sensitivity; visual symptoms (0-5); satisfaction (1-5); spectacle independence rate; and quality of life. Results . Twenty-three patients (27 eyes) were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate, and near were 0.13 ± 0.15 (standard deviation), 0.22 ± 0.15, and 0.16 ± 0.15, respectively. Corresponding mean values for binocular uncorrected VA were 0.00 ± 0.10, 0.08 ± 0.13, and 0.13 ± 0.10, respectively. No eyes lost >1 line of corrected distance VA. Contrast sensitivity at different spatial frequencies between operated and unoperated eyes did not differ significantly (all P > 0.05). Mean score for halos, night glare, starbursts, and satisfaction were 1.46 ± 1.62, 1.85 ± 1.69, 0.78 ± 1.31, and 3.50 ± 1.02, respectively. Eighteen patients (78%) reported complete spectacle independence. Mean composite score of the quality-of-life questionnaire was 90.31 ± 8.50 out of 100. Conclusions . Implantation of the MIOL after myopic LASIK was safe and achieved good visual performance.

Neuronal adaptation to simulated and optically-induced astigmatic defocus.

PubMed

Ohlendorf, Arne; Tabernero, Juan; Schaeffel, Frank

2011-03-25

It is well established that spatial adaptation can improve visual acuity over time in the presence of spherical defocus. It is less well known how far adaptation to astigmatic defocus can enhance visual acuity. We adapted subjects to "simulated" and optically-induced "real" astigmatic defocus, and studied how much they adapt and how selective adaptation was for the axis of astigmatism. Ten subjects with a mean age of 26.7±2.4years (range 23-30) were enrolled in the study, three of them myopic (average spherical equivalent (SE)±SD: -3.08±1.42D) and seven emmetropic (average SE±SD: -0.11±0.18D). All had a corrected minimum visual acuity (VA) of logVA 0.0. For adaptation, subjects watched a movie at 4m distance for 10min that was convolved frame-by-frame with an astigmatic point spread function, equivalent to +3D defocus, or they watched an unfiltered movie but with spectacle frames with a 0/+3D astigmatic trial lenses. Subsequently, visual acuity was determined at the same distance, using high contrast letter acuity charts. Four experiments were performed. In experiment (1), simulated astigmatic defocus was presented both for adaptation and testing, in experiment (2) optically-induced astigmatic defocus was presented both for adaptation and testing of visual acuity. In all these cases, the +3D power meridian was at 0°. In experiments (3) and (4), the +3D power meridian was at 0° during adaptation but rotated to 90° during testing. Astigmatic defocus was simulated in experiment (3) but optically-induced in experiment (4). Experiments 1 and 2: adaptation to either simulated or real astigmatic defocus increased visual acuity in both test paradigms, simulated (change in VA 0.086±0.069 log units; p<0.01) and lens-induced astigmatic defocus (change in VA 0.068±0.031 log units; p<0.001). Experiments 3 and 4: when the axis was rotated, the improvement in visual acuity failed to reach significance, both for simulated (change in VA 0.042±0.079 log units; p=0.13) and lens-induced astigmatic defocus (change in VA 0.038±0.086 log units; p=0.19). Adaptation to astigmatic defocus occurs for both simulated and real defocus, and the effects of adaptation seem to be selective for the axis of astigmatism. These observations suggest that adaptation involves a re-adjustment of the spatial filters selectively for astigmatic meridians, although the underlying mechanism must be more complicated than just changes in shapes of the receptive fields of retinal or cortical neurons. Copyright © 2011 Elsevier Ltd. All rights reserved.

75 FR 80536 - Procedures for the Surrender of Unwanted Controlled Substances by Ultimate Users; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-22

... Administration, Attention: DEA Federal Register Representative/ODL, 8701 Morrissette Drive, Springfield, VA 22152..., Office of Diversion Control, Drug Enforcement Administration, 8701 Morrissette Drive, Springfield, VA... 2006. Teens abuse prescription drugs more than any illicit drug except marijuana--more than cocaine...

Improvement of visual acuity in children with anisometropic amblyopia treated with rotated prisms combined with near activity

PubMed Central

Lin, Chao-Chyun; Chen, Po-Liang

2013-01-01

AIM To evaluate the efficacy of a new modality for improving visual acuity (VA) in pediatric patients with anisometropic amblyopia. METHODS Retrospective and interventional case series. Medical records of 360 children with anisometropic amblyopia treated with a modality that included rotated prisms, lenses, and near activities from January 2008 to January 2012 were analyzed. Characteristics such as improvement of VA and contrast sensitivity in amblyopic eyes and resolution of amblyopia (VA ≤0.1logMAR or a difference of ≤2 lines in logMAR between the eyes) were assessed. RESULTS Among the patients, the mean VA of the amblyopic eyes improved from 0.48logMAR (SD=0.16) to 0.12logMAR (SD=0.16) and the mean VA improvement was 0.36logMAR (SD=0.10, P<0.001). Resolution of amblyopia was achieved in 233 of 360 patients (64.72%). The mean time for resolution of amblyopia was 8.05 weeks (SD=4.83) or 14.14 sessions (SD=8.76). Among the study group, refraction error did not change significantly after treatment (P=0.437). We found that better baseline VA may be related to success and shorten the time to amblyopic resolution. CONCLUSION VA and contrast sensitivity improved with rotated prisms, correcting lenses, and near activities in children with anisometropic amblyopia. The VA improvement by this modality was comparable to other methods. However, the time to resolution of amblyopia was shorter with this method than with other modalities. Rotated prisms combined with near acuity could provide an alternative treatment in children with anisometropic amblyopia who can't tolerant traditional therapy method like patching. PMID:23991384

Desktop publishing and validation of custom near visual acuity charts.

PubMed

Marran, Lynn; Liu, Lei; Lau, George

2008-11-01

Customized visual acuity (VA) assessment is an important part of basic and clinical vision research. Desktop computer based distance VA measurements have been utilized, and shown to be accurate and reliable, but computer based near VA measurements have not been attempted, mainly due to the limited spatial resolution of computer monitors. In this paper, we demonstrate how to use desktop publishing to create printed custom near VA charts. We created a set of six near VA charts in a logarithmic progression, 20/20 through 20/63, with multiple lines of the same acuity level, different letter arrangements in each line and a random noise background. This design allowed repeated measures of subjective accommodative amplitude without the potential artifact of familiarity of the optotypes. The background maintained a constant and spatial frequency rich peripheral stimulus for accommodation across the six different acuity levels. The paper describes in detail how pixel-wise accurate black and white bitmaps of Sloan optotypes were used to create the printed custom VA charts. At all acuity levels, the physical sizes of the printed custom optotypes deviated no more than 0.034 log units from that of the standard, satisfying the 0.05 log unit ISO criterion we used to demonstrate physical equivalence. Also, at all acuity levels, log unit differences in the mean target distance for which reliable recognition of letters first occurred for the printed custom optotypes compared to the standard were found to be below 0.05, satisfying the 0.05 log unit ISO criterion we used to demonstrate functional equivalence. It is possible to use desktop publishing to create custom near VA charts that are physically and functionally equivalent to standard VA charts produced by a commercial printing process.

Comparison of optotypes of Amsterdam Picture Chart with those of Tumbling-E, LEA symbols, ETDRS, and Landolt-C in non-amblyopic and amblyopic patients.

PubMed

Engin, O; Despriet, D D G; van der Meulen-Schot, H M; Romers, A; Slot, X; Sang, M Tjon Fo; Fronius, M; Kelderman, H; Simonsz, H J

2014-12-01

To compare optotypes of the Amsterdam Picture Chart (APK) with those of Landolt-C (LC), Tumbling-E (TE), ETDRS and LEA symbols (LEA), to assess their reliability in measuring visual acuity (VA). We recruited healthy controls with equal VA and amblyopes with ≥2 LogMAR lines interocular difference. New logarithmic charts were developed with LC, TE, ETDRS, LEA, and APK with identical size and spacing (four optotypes) between optotypes. Charts were randomly presented at 5 m under DIN EN ISO 8596 and 8597 conditions. VA was measured with LC (LC-VA), TE, ETDRS, LEA, and APK, using six out of ten optotypes answered correctly as threshold. In 100 controls aged 17-31, LC-VA was -0.207 ± SD 0.089 LogMAR. Visual acuity measured with TE differed from LC-VA by 0.021 (positive value meaning less recognizable), with ETDRS 0.012, with Lea 0.054, and with APK 0.117. In 46 amblyopic eyes with LC-VA <0.5 LogMAR, the difference was for TE 0.017, for ETDRS 0.017, for LEA 0.089, and for APK 0.213. In 13 amblyopic eyes with LC-VA ≥0.5 LogMAR, the difference was for TE 0.122, ETDRS 0.047, LEA 0.057, and APK 0.019. APK optotypes had a lower percentage of passed subjects at each LogMAR line compared to Landolt-C. The 11 APK optotypes had different thresholds. Small APK optotypes were recognized worse than all other optotypes, probably because of their thinner lines. Large APK optotypes were recognized relatively well, possibly reflecting recognition acuity. Differences between the thresholds of the 11 APK optotypes reduced its sensitivity further.

Exceptionally low prevalence of refractive error and visual impairment in schoolchildren from Lao People's Democratic Republic.

PubMed

Casson, Robert J; Kahawita, Shyalle; Kong, Aimee; Muecke, James; Sisaleumsak, Siphetthavong; Visonnavong, Vithoune

2012-10-01

Vientiane Province is an urbanizing region in Southeast Asia. We aimed to determine the prevalence of refractive error and visual impairment in primary school-aged children in this region. Prospective, cross-sectional survey. A total of 2899 schoolchildren from Vientiane Province, Lao People's Democratic Republic (Lao PDR). Ten districts from Vientiane were randomly selected and 2 primary schools were randomly selected from each district. All children aged 6 to 11 years at selected schools were eligible to participate. The examination included visual acuity (VA) testing, cycloplegic retinoscopy with subjective refinement if indicated, ocular motility testing, and anterior segment and fundus examinations in visually impaired children. Cycloplegic refraction and VA. There was an estimated total of 3330 children who were eligible to participate, and data were recorded from 2899 (87%) of these children. Complete refractive data were available on 2842 children (85% of eligible population). The mean spherical equivalent (SE) in the right eyes was +0.60 diopter (D) (95% confidence interval [CI], 0.49-0.72), and the mean SE in the left eyes was +0.59 (95% CI, 0.50-0.68). The prevalence of hyperopia was 2.8% (95% CI, 1.9-3.7; 88 subjects), and the prevalence of myopia was 0.8% (95% CI, 0.3-1.4; 24 subjects). The majority of children (98%; 95% CI, 97.0-99.0) had normal unaided binocular VA (at least 20/32 in their better eye). The overall prevalence of any visual impairment (presenting VA <20/32 in the better eye) was 1.9% (95% CI, 1.0-2.9; 55 subjects). In multivariate logistic regression analysis, age (P = 0.001) was a significant predictor, and female gender (P = 0.08) and Yao ethnicity (P = 0.09) were borderline significant predictors of the presence of any visual impairment. Visual impairment is not a public health concern in this primary school-aged population; however, visually impaired children in the community were not studied. From this baseline, future surveys could determine the effect of increasing urbanization on myopia prevalence in this population. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Contrasting the use of 2 vision-specific quality of life questionnaires in subjects with open-angle glaucoma.

PubMed

Wren, Patricia A; Musch, David C; Janz, Nancy K; Niziol, Leslie M; Guire, Kenneth E; Gillespie, Brenda W

2009-01-01

To compare 2 vision-specific functional status measures to each other and to clinical parameters in the Collaborative Initial Glaucoma Treatment Study (CIGTS). CIGTS participants completed the Visual Activities Questionnaire (VAQ) and the National Eye Institute-Visual Function Questionnaire (NEI-VFQ) and were tested for visual field (VF) and visual acuity (VA). In all, 426 subjects contributed the VAQ and NEI-VFQ scores at 54 months. Pearson correlations were used to assess associations. The VAQ subscales (range, 0 to 100) that assessed light-dark adaptation (mean=66.1), glare disability (66.4), and acuity/spatial vision (67.7) indicated vision-related functions that CIGTS participants found most difficult. On the NEI-VFQ, subjects reported high levels of visual functioning, with mean >/=90 (out of 100) on the total score and in 9 of 12 subscales. General vision (mean=82.6) received the lowest subscale score. Two subscales common to both questionnaires were highly correlated: VA (r=0.68) and peripheral vision (r=0.77) (both P<0.0001). Correlations between participants' perceptions and clinical measures of visual function were in the expected direction, but weaker. Stronger associations were found between clinical measures and the NEI-VFQ than the VAQ. Better eye VF and worse eye VA had the highest number of significant correlations with subjects' perceptions of their visual function. Increasing VF loss was associated with a significant decrease in the overall and peripheral vision subscale scores from both questionnaires, and also several other subscales. CIGTS patients reported excellent visual function on both the NEI-VFQ and VAQ. These findings will help researchers interested in assessing patients' perceptions of their visual function make an informed selection when choosing between the VAQ and the NEI-VFQ.

The First Rapid Assessment of Avoidable Blindness (RAAB) in Thailand

PubMed Central

Isipradit, Saichin; Sirimaharaj, Maytinee; Charukamnoetkanok, Puwat; Thonginnetra, Oraorn; Wongsawad, Warapat; Sathornsumetee, Busaba; Somboonthanakij, Sudawadee; Soomsawasdi, Piriya; Jitawatanarat, Umapond; Taweebanjongsin, Wongsiri; Arayangkoon, Eakkachai; Arame, Punyawee; Kobkoonthon, Chinsuchee; Pangputhipong, Pannet

2014-01-01

Background The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. Methods A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. Results The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5–0.8), 1.3% (95% CI: 1.0–1.6), 12.6% (95% CI: 10.8–14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. Conclusion Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system. PMID:25502762

Hypothesis exploration with visualization of variance

PubMed Central

2014-01-01

Background The Consortium for Neuropsychiatric Phenomics (CNP) at UCLA was an investigation into the biological bases of traits such as memory and response inhibition phenotypes—to explore whether they are linked to syndromes including ADHD, Bipolar disorder, and Schizophrenia. An aim of the consortium was in moving from traditional categorical approaches for psychiatric syndromes towards more quantitative approaches based on large-scale analysis of the space of human variation. It represented an application of phenomics—wide-scale, systematic study of phenotypes—to neuropsychiatry research. Results This paper reports on a system for exploration of hypotheses in data obtained from the LA2K, LA3C, and LA5C studies in CNP. ViVA is a system for exploratory data analysis using novel mathematical models and methods for visualization of variance. An example of these methods is called VISOVA, a combination of visualization and analysis of variance, with the flavor of exploration associated with ANOVA in biomedical hypothesis generation. It permits visual identification of phenotype profiles—patterns of values across phenotypes—that characterize groups. Visualization enables screening and refinement of hypotheses about variance structure of sets of phenotypes. Conclusions The ViVA system was designed for exploration of neuropsychiatric hypotheses by interdisciplinary teams. Automated visualization in ViVA supports ‘natural selection’ on a pool of hypotheses, and permits deeper understanding of the statistical architecture of the data. Large-scale perspective of this kind could lead to better neuropsychiatric diagnostics. PMID:25097666

78 FR 51067 - VA Health Professional Scholarship and Visual Impairment and Orientation and Mobility...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... availability of the program ``to institutions with high numbers of Hispanic students and to historically [[Page... with high numbers of Hispanic students and to Historically Black Colleges and Universities.'' Congress... written request to VA. The requirement for such a written request, however, does not constitute a...

VAP/VAT: video analytics platform and test bed for testing and deploying video analytics

NASA Astrophysics Data System (ADS)

Gorodnichy, Dmitry O.; Dubrofsky, Elan

2010-04-01

Deploying Video Analytics in operational environments is extremely challenging. This paper presents a methodological approach developed by the Video Surveillance and Biometrics Section (VSB) of the Science and Engineering Directorate (S&E) of the Canada Border Services Agency (CBSA) to resolve these problems. A three-phase approach to enable VA deployment within an operational agency is presented and the Video Analytics Platform and Testbed (VAP/VAT) developed by the VSB section is introduced. In addition to allowing the integration of third party and in-house built VA codes into an existing video surveillance infrastructure, VAP/VAT also allows the agency to conduct an unbiased performance evaluation of the cameras and VA software available on the market. VAP/VAT consists of two components: EventCapture, which serves to Automatically detect a "Visual Event", and EventBrowser, which serves to Display & Peruse of "Visual Details" captured at the "Visual Event". To deal with Open architecture as well as with Closed architecture cameras, two video-feed capture mechanisms have been developed within the EventCapture component: IPCamCapture and ScreenCapture.

Pneumatic Displacement with Perfluoropropane Gas and Intravitreal Tissue Plasminogen Activator for Subretinal Subfoveal Hemorrhage after Focal Laser Photocoagulation in Central Serous Chorioretinopathy

PubMed Central

Espinoza, Juan V.; Lasave, Andres F.; Savino-Zari, Dario; Arevalo, Fernando A.

2014-01-01

Objective. To report the visual and anatomic outcomes of pneumatic displacement with perfluoropropane (C3F8) gas and intravitreal tissue plasminogen activator (IVTPA) for subretinal subfoveal hemorrhage after focal laser photocoagulation in central serous chorioretinopathy (CSCR). Method. Interventional, retrospective case report of one eye (one patient). Outcome measures included visual acuity (VA), central macular thickness (CMT), and size of the lesion at two weeks of followup. Fluorescein angiography (FA) and optical coherent tomography (OCT) were used to measure anatomic outcomes. Results. A 35-year-old man with history of chronic CSCR received focal laser photocoagulation in the right eye two days before presentation. At initial examination, VA was 20/200 (ETDRS chart), CMT was 398 μ, and a subretinal subfoveal hemorrhage was seen. Tissue plasminogen activator (tPA) at a dose of 25 µg/0.1 mL was injected intravitreally before intravitreal C3F8 injection, and prone positioning was indicated postoperatively. At 24 hours, the hemorrhage had been displaced inferiorly and VA improved to 20/100. Two weeks later, VA improved to 20/80, CMT decreased to 225 μ, and the hemorrhage decreased without foveal involvement. Conclusions. The technique seems safe and effective in treating visually significant subretinal subfoveal hemorrhage. PMID:25485161

The application of online transcranial random noise stimulation and perceptual learning in the improvement of visual functions in mild myopia.

PubMed

Camilleri, Rebecca; Pavan, Andrea; Campana, Gianluca

2016-08-01

It has recently been demonstrated how perceptual learning, that is an improvement in a sensory/perceptual task upon practice, can be boosted by concurrent high-frequency transcranial random noise stimulation (tRNS). It has also been shown that perceptual learning can generalize and produce an improvement of visual functions in participants with mild refractive defects. By using three different groups of participants (single-blind study), we tested the efficacy of a short training (8 sessions) using a single Gabor contrast-detection task with concurrent hf-tRNS in comparison with the same training with sham stimulation or hf-tRNS with no concurrent training, in improving visual acuity (VA) and contrast sensitivity (CS) of individuals with uncorrected mild myopia. A short training with a contrast detection task is able to improve VA and CS only if coupled with hf-tRNS, whereas no effect on VA and marginal effects on CS are seen with the sole administration of hf-tRNS. Our results support the idea that, by boosting the rate of perceptual learning via the modulation of neuronal plasticity, hf-tRNS can be successfully used to reduce the duration of the perceptual training and/or to increase its efficacy in producing perceptual learning and generalization to improved VA and CS in individuals with uncorrected mild myopia. Copyright © 2016 Elsevier Ltd. All rights reserved.

37 CFR 202.3 - Registration of copyright.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Class VA: Works of the visual arts. This class includes all published and unpublished pictorial, graphic... permission and under the direction of the Visual Arts Division, the application may be submitted... published photographs after consultation and with the permission and under the direction of the Visual Arts...

Evaluation of visual acuity measurements after autorefraction vs manual refraction in eyes with and without diabetic macular edema.

PubMed

Sun, Jennifer K; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W; Andreoli, Christopher M; Edwards, Paul A; Glassman, Adam R; Pavlica, Michael R

2012-04-01

To compare visual acuity (VA) scores after autorefraction vs manual refraction in eyes of patients with diabetes mellitus and a wide range of VAs. The letter score from the Electronic Visual Acuity (EVA) test from the electronic Early Treatment Diabetic Retinopathy Study was measured after autorefraction (AR-EVA score) and after manual refraction (MR-EVA score), which is the research protocol of the Diabetic Retinopathy Clinical Research Network. Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA test using an identical supplemental manual refraction (MR-EVAsuppl score) was performed to determine test-retest variability. In 878 eyes of 456 study participants, the median MR-EVA score was 74 (Snellen equivalent, approximately 20/32). The spherical equivalent was often similar for manual refraction and autorefraction (median difference, 0.00; 5th-95th percentile range, -1.75 to 1.13 diopters). However, on average, the MR-EVA scores were slightly better than the AR-EVA scores, across the entire VA range. Furthermore, the variability between the AR-EVA scores and the MR-EVA scores was substantially greater than the test-retest variability of the MR-EVA scores (P < .001). The variability of differences was highly dependent on the autorefractor model. Across a wide range of VAs at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models that compare most favorably with manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that, with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA.

Interocular difference and duration for doubling of the minimal angle of visual resolution in patients with Stargardt disease.

PubMed

Hajali, Manal; Fishman, Gerald A; Anderson, Robert J; McAnany, J Jason

2009-07-01

To determine the extent of interocular difference in visual acuity (VA) and the time to at least double the minimal angle of resolution (MAR) in a cohort of patients with Stargardt disease. One hundred fifty patients with Stargardt disease who were examined at least four times over a minimum period of 3 years were identified and their VA and age at each visit recorded. The maximum interocular difference of VA was determined by whether the MAR between the two eyes differed by less than a factor of 2 or by a factor of 2 or greater. Differences in maximum VA between the two eyes were also examined according to a Bland-Altman-type approach. One hundred thirty-one eyes from 76 patients were subjected to survival analysis to determine whether the time to at least double the MAR was dependent on age at baseline or starting VA. Of the 150 patients, 48% had interocular MAR that differed maximally by a factor of less than 2. Thirty-five percent showed a maximum interocular difference in their Snellen VA of less than one line. The Bland-Altman- type analysis showed that maximum interocular acuity difference was dependent on the mean acuity of the two eyes. The hazard for at least doubling the MAR was related to baseline vision and patient age. This information has clinical significance for patient counseling and for monitoring possible benefits and patient selection in future treatment trials.

Visual impairment and the incidence of falls and fractures among older people: longitudinal findings from the Blue Mountains Eye Study.

PubMed

Hong, Thomas; Mitchell, Paul; Burlutsky, George; Samarawickrama, Chameen; Wang, Jie Jin

2014-11-04

We assessed the impact of visual impairment on the incidence of falls and fractures in older persons. Of 3654 baseline participants, 2334, 1952, and 1149 were re-examined after 5, 10, and 15 years. Presenting visual acuity (VA) was measured at each examination. Bilateral and unilateral visual impairment was defined as VA worse than 20/40 in the better and worse eye, respectively. Incident visual impairment was defined in eyes with VA 20/40 or better at baseline, which subsequently developed visual impairment. Incidence of falls was assessed over the 12 months before each visit, whereas incidence of fractures was assessed over the 5 years between two visits. Discrete logistic-regression models with time-dependent variables were used to assess associations between visual impairment and subsequent falls and fractures after adjusting for potential confounding variables. The proportions of participants reporting ≥2 falls ranged between 10% and 14%, and proportions reporting fractures ranged between 12% and 21%, across the three follow-up visits. Participants with incident visual impairment were more likely to report ≥2 falls in 5 years, OR (odds ratio) 1.46, 95% confidence interval (CI) 1.04 to 2.04 (bilateral), and OR 1.22, 95% CI 0.98 to 1.51 (unilateral). Compared to participants with normal vision, those with incident unilateral visual impairment had a higher incidence of fractures over 5 years (OR, 1.27; 95% CI, 0.98-1.51). No increased incidence of falls or fractures was evident after 5+ years among participants with visual impairment. In this older cohort, recent development of visual impairment was associated with increased likelihood of subsequent falls and fractures in the next 5 years, independent of other confounding variables. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Comparison of Visual Status of Iranian Military and Commercial Drivers

PubMed Central

Ghasemi, Mohammad; Hoseini Yazdi, Seyed Hosein; Heravian, Javad; Jafarzadehpur, Ebrahim; Rezaee, Maryam

2015-01-01

Background: There is no legal requirement for Iranian military truck drivers to undergo regular visual checkups as compared to commercial truck drivers. Objectives: This study aimed to evaluate the impact of drivers’ visual checkups by comparing the visual function of Iranian military and commercial truck drivers. Patients and Methods: In this comparative cross-sectional study, two hundred military and 200 commercial truck drivers were recruited and their Visual Acuity (VA), Visual Field (VF), color vision and Contrast Sensitivity (CS) were assessed and compared using the Snellen chart, confrontation screening method, D15 test and Pelli-Robson letter chart, respectively. A questionnaire regarding driving exposure and history of motor-vehicle crashes (MVCs) was also filled by drivers. Results were analyzed using an independent samples t-test, one-way ANOVA (assessing difference in number of MVCs across different age groups), chi-square test and Pearson correlation at statistical significance level of P < 0.05. Results: Mean age was 41.6 ± 9.2 for the military truck drivers and 43.4 ± 10.9 for commercial truck drivers (P > 0.05). No significant difference between military and commercial drivers was found in terms of driving experience, number of MVCs, binocular VA, frequency of color vision defects and CS scores. In contrast, the last ocular examination was significantly earlier in military drivers than commercial drivers (P < 0.001). In addition, 4% of military drivers did not meet the national standards to drive as opposed to 2% of commercial drivers. There was a significant but weak correlation between binocular VA and age (r = 0.175, P < 0.001). However, CS showed a significantly moderate correlation with age (r = -0.488, P < 0.001). Conclusions: The absence of legal requirement for regular eye examination in military drivers caused the incompetent drivers to be missed in contrast to commercial drivers. The need for scientific revision of VA standard for Iranian drivers is also discussed. The CS measurement in visual checkups of older drivers deserves to be investigated more thoroughly. PMID:26023333

Demographic and etiologic characteristics of children with traumatic serious hyphema.

PubMed

Türkcü, Fatih Mehmet; Yüksel, Harun; Sahin, Alparslan; Cingü, Kürşat; Arı, Seyhmus; Cınar, Yasin; Sahin, Muhammed; Yıldırım, Adnan; Caça, Ihsan

2013-07-01

We aimed to evaluate the etiologic factors, complications, follow-up, and treatment outcomes in serious hyphema following blunt ocular trauma in childhood. The medical records of 136 patients diagnosed as grade 3 or 4 hyphema due to blunt ocular trauma between January 2006 and December 2011 were evaluated. Visual acuity (VA), complications, and medical and surgical treatments were analyzed. Factors affecting visual prognosis were compared in grade 3 and 4 hyphema cases. The mean age of patients was 9.7±4 years. Etiologic factors for trauma were stone in 53 (39%), bead bullet in 25 (18.4%) and others in 58 (42.6%) patients. The most common complication of grade 3 and 4 hyphema was traumatic mydriasis (19.1%), followed by cataract (9.6%) and glaucoma (5.1%). Medical treatment was successful in 114 (83.8%) patients, and 22 (16.2%) patients underwent surgery. Mean initial and final VA of grade 4 patients were found to be significantly lower than those of grade 3 patients. In grade 3 and 4 hyphema due to blunt trauma, visual prognosis worsened in the presence of additional ocular pathologies. Considering the bad visual prognosis of severe hyphema patients, prompt treatment and close follow-up may prevent complications resulting in poor VA.

Second-year visual acuity outcomes of nAMD patients treated with aflibercept: data analysis from the UK Aflibercept Users Group.

PubMed

Almuhtaseb, H; Johnston, R L; Talks, J S; Lotery, A J

2017-11-01

PurposeTo audit the visual acuity (VA) outcomes achieved at the end of year two in 17 UK centres, which followed the year 1 VIEW protocol in year 1, but a variable approach in year 2 for aflibercept for neovascular macular degeneration (nAMD).Patients and methodsRetrospective data analysis, from an electronic medical record, of a consecutive series of treatment-naive nAMD patients who received aflibercept for 2 consecutive years, having followed the VIEW protocol in year one, defined as eyes having received 7 or 8 injections from baseline.ResultsThe mean number of intravitreal injections (IVI)s during year 2 was 3.7 in 1180 eyes (1083 patients). The mean baseline VA of the whole cohort was 56.3 ETDRS letters, improving to 61.3 at 1 year (+5) and 59.1 (+2.8) at the end of year 2. The mean VA letter score at the end of year 2, stratified by number of IVIs into three groups was as follows: group A, 57.3 (gain of +1.7) (44% of eyes (/=6 IVIs)). Even though there were VA gains in the three groups over the 2-years, there was a drop in VA in year one to two. Eyes that received >/=6 IVIs (group C) had a smaller reduction of VA during year 2 than those which received

Retinal Pigment Epithelial Tears in the Era of Intravitreal Pharmacotherapy: Risk Factors, Pathogenesis, Prognosis and Treatment (An American Ophthalmological Society Thesis)

PubMed Central

Sarraf, David; Joseph, Anthony; Rahimy, Ehsan

2014-01-01

Purpose: To describe the risk factors, pathogenesis, and prognosis of retinal pigment epithelial (RPE) tears and to demonstrate our hypothesis that continued anti–vascular endothelial growth factor (VEGF) therapy after an RPE tear has occurred correlates with improved long-term visual and anatomical outcomes. Methods: We searched a database of 10,089 patients and retrospectively identified a large case series of 56 eyes with neovascular age-related macular degeneration (AMD) complicated by an RPE tear over an 8-year period. Baseline visual acuity (VA) was tabulated and analysis of the RPE tear was performed with multimodal imaging. Follow-up VA, progression of the tear, and severity of fibrosis were evaluated, and each was correlated with number of anti-VEGF injections. Results: Average follow-up for the 56 eyes was 42 months, and mean logMAR VA at baseline was 0.88 (Snellen VA 20/150) with minimal decline over 3 years. LogMAR VA plotted against number of anti-VEGF injections demonstrated that more frequent and cumulative injections correlated with better VA (P<.0001). A greater number of anti-VEGF injections was associated with minimal progression of the RPE tear, reduced fibrosis, and lower risk of a large, end-stage exudative disciform scar. Conclusions: Fifteen to 20% of vascularized pigment epithelial detachments (PEDs) may develop RPE tears after anti-VEGF therapy due to progressive contraction of the type 1 choroidal neovascular membrane in a PED at risk. Continued monitoring of RPE tears for exudative changes warranting anti-VEGF therapy may stabilize VA, improve anatomical outcomes, reduce fibrosis, and decrease the risk of developing a large blinding end-stage exudative disciform scar. PMID:25646033

Audit of cataract surgery in Cadiz: visual outcomes and complications.

PubMed

Royo-Dujardin, L; Alcalde-Vílchez, E; Rodríguez-de la Rúa, E; Novalbos-Ruiz, J P

2018-06-01

To publish the outcomes and complications of age-related cataract surgery in Cadiz (Spain). Due to the lack of national audits, a comparison was made between the results obtained here and those of the most recent European audit, EUREQUO (2013), and the British audit RCOphth NOD (2015). A prospective, longitudinal, before-after study of 312 patients undergoing cataract surgery in the University Hospitals of Puerta del Mar and Puerto Real (Cadiz), in 2013-14. Outcome measurements included sociodemographic characteristics, visual acuity (VA), symptoms secondary to cataract, ocular comorbidity, waiting time, expertise of surgeon (consultant vs. trainee), rate and type of surgical complications. The median age at surgery was 73.92±7.31. Almost all (98.3%) of patients at consultation had a VA ≥0.60logMAR, with a mean pre-surgical VA of 1.01logMAR (0.92-1.10). There was a 6.7% complication rate, with 3.8% posterior capsule ruptures and 2.8% corneal decompensations. No cases of endophthalmitis occurred. The mean post-operative VA was 0.28logMAR (0.22-0.33). More than three-quarters (78.8%) of cases achieved a post-operative VA ≤0.3logMAR, and 27.6% of cases achieved a VA ≤0.0logMAR. Our success rate was inferior to the EUREQUO and RCOphth NOD studies, with the percentage of patients acquiring a postoperative VA ≤0.3logMAR being 98% and 89%, respectively. However, the populations were not comparable. It is hoped that this study will encourage other public hospitals in Spain to undertake audits and share their results, in order to provide a tool for constructive criticism and quality improvement initiatives. Copyright © 2018 Sociedad Española de Oftalmología. All rights reserved.

Prevalence and causes of blindness in an urban area of Paraguay.

PubMed

Yaacov-Peña, Fernando; Jure, David; Ocampos, José; Samudio, Margarita; Furtado, João Marcello; Carter, Marissa; Lansingh, Van Charles

2012-10-01

To determine the prevalence and causes of blindness in Piribebuy, Paraguay. A population based study was conducted from September to November 2007 in Piribebuy, Paraguay. Based on the city map, seven clusters were randomly selected, containing 22 to 36 squares (423 to 578 houses) each, where all subjects > 40 years old who agreed to participate were included in the study. Presenting vision acuity (VA) was obtained for each eye, with 'E' Snellen charts 6 meters far from the patient with appropriate light. Eyes with VA<20/60 were also tested with the pinhole. Objective and subjective refraction was performed, followed by examination of anterior segment under the slit-lamp, Goldmann applanation tonometry, and pupil dilatation with 0.5% tropicamide plus 0.5% phenylephrine, followed by evaluation of the posterior pole. Best corrected visual acuity was used to classify the patients as follows: blindness was defined as visual acuity of the better eye <20/400, low vision as 20/400

Peripheral Visual Fields in ABCA4 Stargardt Disease and Correlation With Disease Extent on Ultra-widefield Fundus Autofluorescence.

PubMed

Abalem, Maria Fernanda; Otte, Benjamin; Andrews, Chris; Joltikov, Katherine A; Branham, Kari; Fahim, Abigail T; Schlegel, Dana; Qian, Cynthia X; Heckenlively, John R; Jayasundera, Thiran

2017-12-01

To evaluate the disease extent on ultra-widefield fundus autofluorescence (UWF-FAF) in patients with ABCA4 Stargardt disease (STGD) and correlate these data with functional outcome measures. Retrospective cross-sectional study. Setting: Kellogg Eye Center, University of Michigan. Sixty-five patients with clinical diagnosis and proven pathogenic variants in the ABCA4 gene. Observational Procedures: The UWF-FAF images were obtained using Optos (200 degrees) and classified into 3 types. Functional testing included kinetic widefield perimetry, full-field electroretinogram (ffERG), and visual acuity (VA). All results were evaluated with respect to UWF-FAF classification. Classification of UWF-FAF; area comprising the I4e, III4e, and IV4e isopters; ffERG patterns; and VA. For UWF-FAF, 27 subjects (41.5%) were classified as type I, 17 (26.2%) as type II, and 21 (32.4%) as type III. The area of each isopter correlated inversely with the extent of the disease and all isopters were able to detect differences among UWF-FAF types (IV4e, P = .0013; III4e, P = .0003; I4e, P < .0001 = 3.93e -8 ). ffERG patterns and VA were also different among the 3 UWF-FAF types (P < .001 = 6.61e- 6 and P < .001 = 7.3e -5 , respectively). Patients with widespread disease presented with more constriction of peripheral visual fields and had more dysfunction on ffERG and worse VA compared to patients with disease confined to the macula. UWF-FAF images may provide information for estimating peripheral and central visual function in STGD. Copyright © 2017. Published by Elsevier Inc.

[Vitrectomy for idiopathic and secondary preretinal macular membrane].

PubMed

Oficjalska-Młyńczak, Jolanta; Jamrozy-Witkowska, Agnieszka

2004-01-01

To evaluate the results of pars plana vitrectomy and membrane stripping for idiopathic and secondary preretinal macular membrane (PMM). Twenty one consecutive subjects (21 eyes) ranging in age from 40 to 78 (mean 66.9) with PMM underwent vitrectomy and membrane peeling. 17 cases had membranes that were considered idiopathic, and 4 cases were associated with other disorders: 3 occurred after successful retinal reattachment surgery, 1--after laserotherapy in the course of diabetic retinopathy. Visual acuity (VA), Amsler grid, and postoperative complications were assessed. The follow-up was 1 to 22 months, mean 5.7. Visual acuity improved postoperatively in 15 eyes (71.4%), at least two lines on the Snellen chart in 8 eyes (38.1%), entirely in patients with idiopathic PMM. It remained unchanged in 3 eyes (14.3%) and deteriorated in 3 eyes (14.3%). Eyes with transparent membrane showed greater visual improvement than opaque ones. The preoperative Amsler test was positive in 15 patients (71.4%), postoperatively--in 4 cases (19%). 2 idiopathic cases with VA of 0.7 showed postoperatively VA of 1.0. Complications included retinal detachment in 2 eyes (1 in idiopathic and 1 in secondary PMM), and development of nuclear sclerotic cataract in 2 eyes. At 6 months of follow-up, a residual membrane formation in 1 cases appeared. Macular pseudohole was observed in 1 eye with no impact on visual results. 1. Vitrectomy with membrane peeling for preretinal macular membrane provides improvement in visual acuity and reduces metamorphopsia 2. Thin, cellophane-like appearance of the membrane gives a better prognosis of visual function improvement.

Challenges Associated with Estimating Utility in Wet Age-Related Macular Degeneration: A Novel Regression Analysis to Capture the Bilateral Nature of the Disease.

PubMed

Hodgson, Robert; Reason, Timothy; Trueman, David; Wickstead, Rose; Kusel, Jeanette; Jasilek, Adam; Claxton, Lindsay; Taylor, Matthew; Pulikottil-Jacob, Ruth

2017-10-01

The estimation of utility values for the economic evaluation of therapies for wet age-related macular degeneration (AMD) is a particular challenge. Previous economic models in wet AMD have been criticized for failing to capture the bilateral nature of wet AMD by modelling visual acuity (VA) and utility values associated with the better-seeing eye only. Here we present a de novo regression analysis using generalized estimating equations (GEE) applied to a previous dataset of time trade-off (TTO)-derived utility values from a sample of the UK population that wore contact lenses to simulate visual deterioration in wet AMD. This analysis allows utility values to be estimated as a function of VA in both the better-seeing eye (BSE) and worse-seeing eye (WSE). VAs in both the BSE and WSE were found to be statistically significant (p < 0.05) when regressed separately. When included without an interaction term, only the coefficient for VA in the BSE was significant (p = 0.04), but when an interaction term between VA in the BSE and WSE was included, only the constant term (mean TTO utility value) was significant, potentially a result of the collinearity between the VA of the two eyes. The lack of both formal model fit statistics from the GEE approach and theoretical knowledge to support the superiority of one model over another make it difficult to select the best model. Limitations of this analysis arise from the potential influence of collinearity between the VA of both eyes, and the use of contact lenses to reflect VA states to obtain the original dataset. Whilst further research is required to elicit more accurate utility values for wet AMD, this novel regression analysis provides a possible source of utility values to allow future economic models to capture the quality of life impact of changes in VA in both eyes. Novartis Pharmaceuticals UK Limited.

Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia.

PubMed

Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

2016-02-01

To present and evaluate a new screening protocol for amblyopia in preschool children. Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

PubMed Central

Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

2016-01-01

Aim To present and evaluate a new screening protocol for amblyopia in preschool children. Methods Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. Results 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. Conclusion The ZAPS study used the most discriminative VA test with optotypes in lines as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia. PMID:26935612

Development of Sensitivity to Audiovisual Temporal Asynchrony during Mid-Childhood

PubMed Central

Kaganovich, Natalya

2015-01-01

Temporal proximity is one of the key factors determining whether events in different modalities are integrated into a unified percept. Sensitivity to audiovisual temporal asynchrony has been studied in adults in great detail. However, how such sensitivity matures during childhood is poorly understood. We examined perception of audiovisual temporal asynchrony in 7-8-year-olds, 10-11-year-olds, and adults by using a simultaneity judgment task (SJT). Additionally, we evaluated whether non-verbal intelligence, verbal ability, attention skills, or age influenced children's performance. On each trial, participants saw an explosion-shaped figure and heard a 2 kHz pure tone. These occurred at the following stimulus onset asynchronies (SOAs) - 0, 100, 200, 300, 400, and 500 ms. In half of all trials, the visual stimulus appeared first (VA condition) while in another half, the auditory stimulus appeared first (AV condition). Both groups of children were significantly more likely than adults to perceive asynchronous events as synchronous at all SOAs exceeding 100 ms, in both VA and AV conditions. Furthermore, only adults exhibited a significant shortening of RT at long SOAs compared to medium SOAs. Sensitivities to the VA and AV temporal asynchronies showed different developmental trajectories, with 10-11-year-olds outperforming 7-8-year-olds at the 300-500 ms SOAs, but only in the AV condition. Lastly, age was the only predictor of children's performance on the SJT. These results provide an important baseline against which children with developmental disorders associated with impaired audiovisual temporal function, such as autism, specific language impairment, and dyslexia may be compared. PMID:26569563

Inner and outer segment junction (IS/OS line) integrity in ocular Behçet's disease.

PubMed

Yüksel, Harun; Türkcü, Fatih M; Sahin, Muhammed; Cinar, Yasin; Cingü, Abdullah K; Ozkurt, Zeynep; Sahin, Alparslan; Ari, Seyhmus; Caça, Ihsan

2014-08-01

In this study, we examined the spectral domain optical coherence tomography (OCT) findings of ocular Behçet's disease (OB) in patients with inactive uveitis. Specifically, we analyzed the inner and outer segment junction (IS/OS line) integrity and the effect of disturbed IS/OS line integrity on visual acuity. Patient files and OCT images of OB patients who had been followed-up between January and June of the year 2013 at the Dicle University Eye Clinic were evaluated retrospectively. Sixty-six eyes of 39 patients were included the study. OCT examination of the patients with inactive OB revealed that approximately 25% of the patients had disturbed IS/OS and external limiting membrane (EML) line integrity, lower visual acuity (VA), and lower macular thickness than others. Linear regression analysis revealed that macular thickness was not an independent variable for VA. In contrast, the IS/OS line integrity was an independent variable for VA in inactive OB patients. In this study, we showed that the IS/OS line integrity was an independent variable for VA in inactive OB patients. Further prospective studies are needed to evaluate the integrity of the IS/OS line in OB patients.

Preschool vision screening in a Swedish city region: results after alteration of criteria for referral to eye clinics.

PubMed

Hård, Anna-Lena; Sjödell, Lena; Borres, Magnus P; Zetterberg, Ingrid; Sjöstrand, Johan

2002-12-01

To investigate the results of preschool vision screening and to evaluate new referral criteria in a Swedish city region. Prior to 1992, all children with visual acuity (VA) of less than 0.8 at the age of 4 years were referred to an eye clinic. Since 1992, those with slightly reduced VA (0.65 in each eye or 0.65 in one eye and 0.8 in the other) have been retested at 5.5 years of age and referred if their VA is less than 0.8. In a prospective study, the results of vision testing were collected for all children (n = 483) born in 1989-92 inclusive and registered at one child health centre at 4 years of age. The study also involved 123 other children scheduled for retesting at the age of 5.5 years. The results of the examinations and treatments at the eye clinic are evaluated. Few of the children with slightly reduced VA who were retested at the age of 5.5 years had visual defects that required treatment. In those who were treated, the results of treatment were good. The new screening criteria appear to be appropriate and are recommended.

A Mouse Model of Visual Perceptual Learning Reveals Alterations in Neuronal Coding and Dendritic Spine Density in the Visual Cortex.

PubMed

Wang, Yan; Wu, Wei; Zhang, Xian; Hu, Xu; Li, Yue; Lou, Shihao; Ma, Xiao; An, Xu; Liu, Hui; Peng, Jing; Ma, Danyi; Zhou, Yifeng; Yang, Yupeng

2016-01-01

Visual perceptual learning (VPL) can improve spatial vision in normally sighted and visually impaired individuals. Although previous studies of humans and large animals have explored the neural basis of VPL, elucidation of the underlying cellular and molecular mechanisms remains a challenge. Owing to the advantages of molecular genetic and optogenetic manipulations, the mouse is a promising model for providing a mechanistic understanding of VPL. Here, we thoroughly evaluated the effects and properties of VPL on spatial vision in C57BL/6J mice using a two-alternative, forced-choice visual water task. Briefly, the mice underwent prolonged training at near the individual threshold of contrast or spatial frequency (SF) for pattern discrimination or visual detection for 35 consecutive days. Following training, the contrast-threshold trained mice showed an 87% improvement in contrast sensitivity (CS) and a 55% gain in visual acuity (VA). Similarly, the SF-threshold trained mice exhibited comparable and long-lasting improvements in VA and significant gains in CS over a wide range of SFs. Furthermore, learning largely transferred across eyes and stimulus orientations. Interestingly, learning could transfer from a pattern discrimination task to a visual detection task, but not vice versa. We validated that this VPL fully restored VA in adult amblyopic mice and old mice. Taken together, these data indicate that mice, as a species, exhibit reliable VPL. Intrinsic signal optical imaging revealed that mice with perceptual training had higher cut-off SFs in primary visual cortex (V1) than those without perceptual training. Moreover, perceptual training induced an increase in the dendritic spine density in layer 2/3 pyramidal neurons of V1. These results indicated functional and structural alterations in V1 during VPL. Overall, our VPL mouse model will provide a platform for investigating the neurobiological basis of VPL.

The Relationship between Visual Impairment and Health-Related Quality of Life in Korean Adults: The Korea National Health and Nutrition Examination Survey (2008–2012)

PubMed Central

Park, Yuli; Shin, Jeong Ah; Yang, Suk Woo; Yim, Hyeon Woo; Kim, Hyun Seung; Park, Young-Hoon

2015-01-01

Introduction To evaluate health-related quality of life (HRQoL) in Korean adults with visual impairment(VI) using various measures based on a nationally distributed sample. Methods Using the Korea National Health and Nutrition Examination Survey (KNHANES, 2008–2012) data, we compared EuroQol five-dimensional questionnaire (EQ-5D) and EQ-visual analogue scale (VAS) scores after adjusting for socio-demographic and psychosocial factors as well as for comorbidities with VI. Logistic regressions were used to elucidate determinants for the lowest quintile HRQoL scales according to VI severity. Uncorrected visual acuity (VA) which implies vision of ordinary life was measured using an international standard vision chart based on Snellen scale. Results 28,825 participants (sum of weights; 37,562,376) were included in the analysis. The mean EQ-5D and EQ-VAS scores were significantly lower in the VI groups than in the normal vision (defined as VA 20/20-20/25) group based on the better or worse seeing eye (P<.0001 and P<.0001, respectively). Participants with moderate (VA 20/80-20/160) and severe VI (VA ≤20/200) had higher scores of multivariate-adjusted odd ratios (aORs) for the lowest quintile than did the normal vision group which was particularly evident in the results from EQ-5D, whereas the results of the mild VI (VA 20/32-20/63) group did not identify significant differences from the normal vision group independent of classification according to the better or the worse seeing eye. Conversely, EQ-VAS revealed significantly higher score of multivariate-aORs for the lowest quintile in participants with mild VI either for the better or worse seeing eye. Conclusions The severity of VI was definitely associated with impaired HRQoL compared with the normal vision population. The analyses presented here elicited even mild VI could potentially deteriorate the health-related quality of life (or subjective perception of health quality) and therefore, therapeutic approaches should also focus on the subjective perception and better management of health condition. PMID:26192763

Visual outcomes after spectacles treatment in children with bilateral high refractive amblyopia.

PubMed

Lin, Pei-Wen; Chang, Hsueh-Wen; Lai, Ing-Chou; Teng, Mei-Ching

2016-11-01

The aim was to investigate the visual outcomes of treatment with spectacles for bilateral high refractive amblyopia in children three to eight years of age. Children with previously untreated bilateral refractive amblyopia were enrolled. Bilateral high refractive amblyopia was defined as visual acuity (VA) being worse than 6/9 in both eyes in the presence of 5.00 D or more of hyperopia, 5.00 D or more of myopia and 2.00 D or more of astigmatism. Full myopic and astigmatic refractive errors were corrected, and the hyperopic refractive errors were corrected within 1.00 D of the full correction. All children received visual assessments at four-weekly intervals. VA, Worth four-dot test and Randot preschool stereotest were assessed at baseline and every four weeks for two years. Twenty-eight children with previously untreated bilateral high refractive amblyopia were enrolled. The mean VA at baseline was 0.39 ± 0.24 logMAR and it significantly improved to 0.21, 0.14, 0.11, 0.05 and 0.0 logMAR at four, eight, 12, 24 weeks and 18 months, respectively (all p = 0.001). The mean stereoacuity (SA) was 1,143 ± 617 arcsec at baseline and it significantly improved to 701, 532, 429, 211 and 98 arcsec at four, eight, 12, 24 weeks and 18 months, respectively (all p = 0.001). The time interval for VA achieving 6/6 was significantly shorter in the eyes of low spherical equivalent (SE) (-2.00 D < SE < +2.00 D) than in those of high SE (SE > +2.00 D) (3.33 ± 2.75 months versus 8.11 ± 4.56 months, p = 0.0005). All subjects had normal fusion on Worth four-dot test at baseline and all follow-up visits. Refractive correction with good spectacles compliance improves VA and SA in young children with bilateral high refractive amblyopia. Patients with greater amounts of refractive error will achieve resolution of amblyopia with a longer time. © 2016 Optometry Australia.

Factors related to attrition from VA healthcare use: findings from the National Survey of Women Veterans.

PubMed

Hamilton, Alison B; Frayne, Susan M; Cordasco, Kristina M; Washington, Donna L

2013-07-01

While prior research characterizes women Veterans' barriers to accessing and using Veterans Health Administration (VA) care, there has been little attention to women who access VA and use services, but then discontinue use. Recent data suggest that among women Veterans, there is a 30 % attrition rate within 3 years of initial VA use. To compare individual characteristics and perceptions about VA care between women Veteran VA attriters (those who discontinue use) and non-attriters (those who continue use), and to compare recent versus remote attriters. Cross-sectional, population-based 2008-2009 national telephone survey. Six hundred twenty-six attriters and 2,065 non-attriters who responded to the National Survey of Women Veterans. Population weighted demographic, military and health characteristics; perceptions about VA healthcare; length of time since last VA use; among attriters, reasons for no longer using VA care. Fifty-four percent of the weighted VA ever user population reported that they no longer use VA. Forty-five percent of attrition was within the past ten years. Attriters had better overall health (p = 0.007), higher income (p < 0.001), and were more likely to have health insurance (p < 0.001) compared with non-attriters. Attriters had less positive perceptions of VA than non-attriters, with attriters having lower ratings of VA quality and of gender-specific features of VA care (p < 0.001). Women Veterans who discontinued VA use since 2001 did not differ from those with more remote VA use on most measures of VA perceptions. Overall, among attriters, distance to VA sites of care and having alternate insurance coverage were the most common reasons for discontinuing VA use. We found high VA attrition despite recent advances in VA care for women Veterans. Women's attrition from VA could reduce the critical mass of women Veterans in VA and affect current system-wide efforts to provide high-quality care for women Veterans. An understanding of reasons for attrition can inform organizational efforts to re-engage women who have attrited, to retain current users, and potentially to attract new VA patients.

Association of Baseline Visual Acuity and Retinal Thickness With 1-Year Efficacy of Aflibercept, Bevacizumab, and Ranibizumab for Diabetic Macular Edema.

PubMed

Wells, John A; Glassman, Adam R; Jampol, Lee M; Aiello, Lloyd Paul; Antoszyk, Andrew N; Baker, Carl W; Bressler, Neil M; Browning, David J; Connor, Crystal G; Elman, Michael J; Ferris, Frederick L; Friedman, Scott M; Melia, Michele; Pieramici, Dante J; Sun, Jennifer K; Beck, Roy W

2016-02-01

Comparisons of the relative effect of 3 anti-vascular endothelial growth factor agents to treat diabetic macular edema warrant further assessment. To provide additional outcomes from a randomized trial evaluating 3 anti-vascular endothelial growth factor agents for diabetic macular edema within subgroups based on baseline visual acuity (VA) and central subfield thickness (CST) as evaluated on optical coherence tomography. Post hoc exploratory analyses were conducted of randomized trial data on 660 adults with diabetic macular edema and decreased VA (Snellen equivalent, approximately 20/32 to 20/320). The original study was conducted between August 22, 2012, and August 28, 2013. Analysis was conducted from January 7 to June 2, 2015. Repeated 0.05-mL intravitreous injections of 2.0 mg of aflibercept (224 eyes), 1.25 mg of bevacizumab (218 eyes), or 0.3 mg of ranibizumab (218 eyes) as needed per protocol. One-year VA and CST outcomes within prespecified subgroups based on both baseline VA and CST thresholds, defined as worse (20/50 or worse) or better (20/32 to 20/40) VA and thicker (≥400 µm) or thinner (250 to 399 µm) CST. In the subgroup with worse baseline VA (n = 305), irrespective of baseline CST, aflibercept showed greater improvement than bevacizumab or ranibizumab for several VA outcomes. In the subgroup with better VA and thinner CST at baseline (61-73 eyes across 3 treatment groups), VA outcomes showed little difference between groups; mean change was +7.2, +8.4, and +7.6 letters in the aflibercept, bevacizumab, and ranibizumab groups, respectively. However, in the subgroup with better VA and thicker CST at baseline (31-43 eyes), there was a suggestion of worse VA outcomes in the bevacizumab group; mean change from baseline to 1 year was +9.5, +5.4, and +9.5 letters in the aflibercept, bevacizumab, and ranibizumab groups, respectively, and VA letter score was greater than 84 (approximately 20/20) in 21 of 33 (64%), 7 of 31 (23%), and 21 of 43 (49%) eyes, respectively. The adjusted differences and 95% CIs were 39% (17% to 60%) for aflibercept vs bevacizumab, 25% (5% to 46%) for ranibizumab vs bevacizumab, and 13% (-8% to 35%) for aflibercept vs ranibizumab. These post hoc secondary findings suggest that for eyes with better initial VA and thicker CST, some VA outcomes may be worse in the bevacizumab group than in the aflibercept and ranibizumab groups. Given the exploratory nature of these analyses and the small sample size within subgroups, caution is suggested when using the data to guide treatment considerations for patients. clinicaltrials.gov Identifier: NCT01627249.

[Visual acuity and magnification requirement after ranibizumab in patients with wet age-related macular degeneration].

PubMed

Kloos, P; Bernasconi, P; Estermann, S; Bachmann, B; Rutishauser, Y; Thölen, A

2008-05-01

The purpose of this study was to examine the visual outcome by measuring visual acuity (VA) and magnification requirement (MR) in patients with wet AMD after repeated intravitreal injections of ranibizumab. A total of 195 eyes were treated with repeated intravitreal injections of ranibizumab "as needed". VA (Snellen chart) and MR (SZB reading chart) at baseline of 114 eyes with occult or minimally classic lesions, 42 eyes with predominantly classic lesions and 39 with retinal angiomatous proliferations (RAP) were compared at 3 and 6 months after beginning of treatment. The whole group of 195 patients with wet AMD (688 intravitreal injections within 6 months) demonstrated a mean improvement of VA of 0.72 lines after 3 months (p < 0.001) and 1.54 lines after 6 months (p < 0.001) and a mean improvement of MR of 0.59 log units after 3 months (p < 0.001) and 0.73 log units after 6 months (p < 0.001). Mean change in VA after 3 and 6 months demonstrated a significant improvement (p < 0.001 to p < 0.05) for eyes with occult CNV (+ 0.8 /+ 1.6 lines) and RAP (+ 1.2 /+ 1.9 lines) whereas mean improvement in VA for classic CNV (+ 0.02 /+ 0.87 lines) did not reach significance compared to baseline. Comparable results were obtained for the mean change of MR after 3 and 6 months for eyes with occult CNV (+ 0.75 log units/+ 0.92 log units). For eyes with RAP mean improvement of MR was + 0.74 log units after 3 months (p < 0.05) and it was not significant with + 0.8 log units after 6 months (p > 0.05). MR did not show a significant change during follow-up for classic CNV. Apart from eyes with classic CNV, in more than 90 % of the eyes both VA and MR remained stable or improved (loss < 3 lines in VA or deterioration of MR of < 3 log units). Although 45 % of the eyes with predominantly classic CNV had received photodynamic therapies with Verteporfin prior to the intravitreal injections with ranibizumab, MR remained stable in 80 % over 6 months. With repeated injections of ranibizumab "as needed", VA could be improved as well as MR could be lowered in a majority of patients with wet AMD and therefore reading ability could be optimized. Over 6 months the treatment frequency was lower compared to the monthly administration.

Optical treatment of amblyopia in older children and adults is essential prior to enrolment in a clinical trial.

PubMed

Gao, Tina Y; Anstice, Nicola; Babu, Raiju J; Black, Joanna M; Bobier, William R; Dai, Shuan; Guo, Cindy X; Hess, Robert F; Jenkins, Michelle; Jiang, Yannan; Kearns, Lisa; Kowal, Lionel; Lam, Carly S Y; Pang, Peter C K; Parag, Varsha; South, Jayshree; Staffieri, Sandra Elfride; Wadham, Angela; Walker, Natalie; Thompson, Benjamin

2018-03-01

Optical treatment alone can improve visual acuity (VA) in children with amblyopia, thus clinical trials investigating additional amblyopia therapies (such as patching or videogames) for children require a preceding optical treatment phase. Emerging therapies for adult patients are entering clinical trials. It is unknown whether optical treatment is effective for adults with amblyopia and whether an optical correction phase is required for trials involving adults. We examined participants who underwent optical treatment in the Binocular Treatment for Amblyopia using Videogames (BRAVO) clinical trial (ANZCTR ID: ACTRN12613001004752). Participants were recruited in three age groups (7 to 12, 13 to 17, or ≥18 years), and had unilateral amblyopia due to anisometropia and/or strabismus, with amblyopic eye VA of 0.30-1.00 logMAR (6/12 to 6/60, 20/40 to 20/200). Corrective lenses were prescribed based on cycloplegic refraction to fully correct any anisometropia. VA was assessed using the electronic visual acuity testing algorithm (e-ETDRS) test and near stereoacuity was assessed using the Randot Preschool Test. Participants were assessed every four weeks up to 16 weeks, until either VA was stable or until amblyopic eye VA improved to better than 0.30 logMAR, rendering the participant ineligible for the trial. Eighty participants (mean age 24.6 years, range 7.6-55.5 years) completed four to 16 weeks of optical treatment. A small but statistically significant mean improvement in amblyopic eye VA of 0.05 logMAR was observed (S.D. 0.08 logMAR; paired t-test p < 0.0001). Twenty-five participants (31%) improved by ≥1 logMAR line and of these, seven (9%) improved by ≥2 logMAR lines. Stereoacuity improved in 15 participants (19%). Visual improvements were not associated with age, presence of strabismus, or prior occlusion treatment. Two adult participants withdrew due to intolerance to anisometropic correction. Sixteen out of 80 participants (20%) achieved better than 0.30 logMAR VA in the amblyopic eye after optical treatment. Nine of these participants attended additional follow-up and four (44%) showed further VA improvements. Improvements from optical treatment resulted in one-fifth of participants becoming ineligible for the main clinical trial. Studies investigating additional amblyopia therapies must include an appropriate optical treatment only phase and/or parallel treatment group regardless of patient age. Optical treatment of amblyopia in adult patients warrants further investigation. © 2018 The Authors Ophthalmic & Physiological Optics © 2018 The College of Optometrists.

Temporal Evolution and Dose-Volume Histogram Predictors of Visual Acuity After Proton Beam Radiation Therapy of Uveal Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polishchuk, Alexei L.; Mishra, Kavita K., E-mail: Kavita.Mishra@ucsf.edu; Weinberg, Vivian

2017-01-01

Purpose: To perform an in-depth temporal analysis of visual acuity (VA) outcomes after proton beam radiation therapy (PBRT) in a large, uniformly treated cohort of uveal melanoma (UM) patients, to determine trends in VA evolution depending on pretreatment and temporally defined posttreatment VA measurements; and to investigate the relevance of specific patient, tumor and dose-volume parameters to posttreatment vision loss. Methods and Materials: Uveal melanoma patients receiving PBRT were identified from a prospectively maintained database. Included patients (n=645) received 56 GyE in 4 fractions, had pretreatment best corrected VA (BCVA) in the affected eye of count fingers (CF) or better, withmore » posttreatment VA assessment at specified post-PBRT time point(s). Patients were grouped according to the pretreatment BCVA into favorable (≥20/40) or unfavorable (20/50-20/400) and poor (CF) strata. Temporal analysis of BCVA changes was described, and univariate and forward stepwise multivariate logistic regression analyses were performed to identify predictors for VA loss. Results: Median VA follow-up was 53 months (range, 3-213 months). At 60-month follow up, among evaluable treated eyes with favorable pretreatment BCVA, 45% retained BCVA ≥20/40, whereas among evaluable treated eyes with initially unfavorable/poor BCVA, 21% had vision ≥20/100. Among those with a favorable initial BCVA, attaining BCVA of ≥20/40 at any posttreatment time point was associated with subsequent maintenance of excellent BCVA. Multivariate analysis identified volume of the macula receiving 28GyE (P<.0001) and optic nerve (P=.0004) as independent dose-volume histogram predictors of 48-month post-PBRT vision loss among initially favorable treated eyes. Conclusions: Approximately half of PBRT-treated UM eyes with excellent pretreatment BCVA assessed at 5 years after treatment will retain excellent long-term vision. 28GyE macula and optic nerve dose-volume histogram parameters allow for rational treatment planning optimization that may lead to improved visual outcomes. The detailed temporal analysis with intermediate as well as long-term functional prognosis, and the relationship of outcomes with clinical and treatment planning parameters, is critical for informed care of UM patients before and after PBRT.« less

Bilateral Medial Medullary Infarction with Nondominant Vertebral Artery Occlusion.

PubMed

Zhang, Lei; Zhang, Gui-lian; Du, Ju-mei; Ma, Zhu-lin

2015-09-01

Bilateral medial medullary infarction (MMI) is a rare stroke subtype. Here, we report a case with bilateral MMI caused by nondominant vertebral artery occlusion confirmed by brain digital subtraction angiography and magnetic resonance imaging basi-parallel-anatomical-scanning. We highlight that anterior spinal arteries could originate from a unilateral vertebral artery (VA). Radiologists and neurologists should pay attention to the nondominant VA as bilateral MMI may be induced by occlusion of nondominant VA that supplies the bilateral anteromedial territories of the medulla. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

[National survey of blindness and avoidable visual impairment in Argentina, 2013].

PubMed

Barrenechea, Rosario; de la Fuente, Inés; Plaza, Roberto Gustavo; Flores, Nadia; Segovia, Lía; Villagómez, Zaida; Camarero, Esteban Elián; Zepeda-Romero, Luz Consuelo; Lansingh, Van C; Limburg, Hans; Silva, Juan Carlos

2015-01-01

Determine the prevalence of blindness and avoidable visual impairment in Argentina, its causes, the coverage of cataract surgery, and the barriers that hinder access to these services. Cross-sectional population study conducted between May and November 2013 using the standard methodology for rapid assessment of avoidable blindness (RAAB), with a random cluster sampling of 50 people aged 50 years or more, -representative of the entire country. Participants' visual acuity (VA) was measured and the lens and posterior pole were examined by direct ophthalmoscopy. An assessment was made of the causes of having VA < 20/60, the coverage and quality of cataract surgery, and the barriers to accessing treatment. 3 770 people were assessed (92.0% of the projected number). The prevalence of blindness was 0.7% (confidence interval of 95%: 0.4-1.0%). Unoperated cataract was the main cause of blindness and severe visual impairment (44.0% and 71.1%, respectively), while the main cause of moderate visual impairment was uncorrected refractive errors (77.8%). Coverage of cataract surgery was of 97.1%, and 82.0% of operated eyes achieved VA ≥ 20/60. The main barriers to receiving this treatment were fear of the surgical procedure or of a poor result (34.9%), the cost (30.2%), and not having access to the treatment (16.3%). There is a low prevalence of blindness in the studied population and cataract is the main cause of blindness and severe visual impairment. Efforts should continue to extend coverage of cataract surgery, enhance preoperative evaluation, improve calculations of the intraocular lenses that patients need, and correct post-operative refractive errors with greater precision.

The contributions of visual and central attention to visual working memory.

PubMed

Souza, Alessandra S; Oberauer, Klaus

2017-10-01

We investigated the role of two kinds of attention-visual and central attention-for the maintenance of visual representations in working memory (WM). In Experiment 1 we directed attention to individual items in WM by presenting cues during the retention interval of a continuous delayed-estimation task, and instructing participants to think of the cued items. Attending to items improved recall commensurate with the frequency with which items were attended (0, 1, or 2 times). Experiments 1 and 3 further tested which kind of attention-visual or central-was involved in WM maintenance. We assessed the dual-task costs of two types of distractor tasks, one tapping sustained visual attention and one tapping central attention. Only the central attention task yielded substantial dual-task costs, implying that central attention substantially contributes to maintenance of visual information in WM. Experiment 2 confirmed that the visual-attention distractor task was demanding enough to disrupt performance in a task relying on visual attention. We combined the visual-attention and the central-attention distractor tasks with a multiple object tracking (MOT) task. Distracting visual attention, but not central attention, impaired MOT performance. Jointly, the three experiments provide a double dissociation between visual and central attention, and between visual WM and visual object tracking: Whereas tracking multiple targets across the visual filed depends on visual attention, visual WM depends mostly on central attention.

Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration

PubMed Central

Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W.; Jackson, Mary Lou

2018-01-01

Purpose Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. Methods We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Results Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). Conclusion In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL. PMID:29746512

Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration.

PubMed

Roh, Miin; Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W; Jackson, Mary Lou

2018-01-01

Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL.

Macular morphology and visual acuity in the comparison of age-related macular degeneration treatments trials.

PubMed

Jaffe, Glenn J; Martin, Daniel F; Toth, Cynthia A; Daniel, Ebenezer; Maguire, Maureen G; Ying, Gui-Shuang; Grunwald, Juan E; Huang, Jiayan

2013-09-01

To describe the effects of treatment for 1 year with ranibizumab or bevacizumab on macular morphology and the association of macular morphology with visual acuity (VA) in eyes with neovascular age-related macular degeneration (AMD). Prospective cohort study within a randomized clinical trial. Participants in the Comparison of Age-related Macular Degeneration Treatments Trials. Participants were assigned randomly to treatment with ranibizumab or bevacizumab on a monthly or as-needed schedule. Optical coherence tomography (OCT), fluorescein angiography (FA), color fundus photography (FP), and VA testing were performed periodically throughout 52 weeks. Masked readers graded images. General linear models were applied to evaluate effects of time and treatment on outcomes. Fluid type and location and thickness by OCT, size, and lesion composition on FP, FA, and VA. Intraretinal fluid (IRF), subretinal fluid (SRF), subretinal pigment epithelium fluid, and retinal, subretinal, and subretinal tissue complex thickness decreased in all treatment groups. A higher proportion of eyes treated monthly with ranibizumab had fluid resolution at 4 weeks, and the difference persisted through 52 weeks. At 52 weeks, there was little association between the presence of fluid of any type (without regard to fluid location) and the mean VA. However, at all time points, eyes with residual IRF, especially foveal IRF, had worse mean VA (9 letters) than those without IRF. Eyes with abnormally thin (<120 μm) or thick (>212 μm) retinas had worse VA than those with normal thickness (120-212 μm). At week 52, eyes with larger neovascular lesions or with foveal scar had worse VA than eyes without these features. Anti-vascular endothelial growth factor (VEGF) therapy reduced lesion activity and improved VA in all treatment groups. At all time points, eyes with residual IRF had worse VA than those without. Eyes with abnormally thin or thick retinas, residual large lesions, and scar also had worse VA. Monthly ranibizumab dosing yielded more eyes with no fluid and an abnormally thin retina, although the long-term significance is unknown. These results have important treatment implications in eyes undergoing anti-VEGF therapy for neovascular AMD. Proprietary or commercial disclosure may be found after the references. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Macular Morphology and Visual Acuity in the Second Year of the Comparison of Age-Related Macular Degeneration Treatments Trials.

PubMed

Sharma, Sumit; Toth, Cynthia A; Daniel, Ebenezer; Grunwald, Juan E; Maguire, Maureen G; Ying, Gui-Shuang; Huang, Jiayan; Martin, Daniel F; Jaffe, Glenn J

2016-04-01

To describe the association between morphologic features on fundus photography (FP), fluorescein angiography (FA), and optical coherence tomography (OCT) and visual acuity (VA) in the second year of the Comparison of Age-related Macular Degeneration Treatments Trials (CATT). Prospective cohort study within a randomized clinical trial. Participants in the CATT. Study eye eligibility required angiographic and OCT evidence of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and VA between 20/25 and 20/320. Treatment was assigned randomly to ranibizumab or bevacizumab with 3 different dosing regimens over a 2-year period. Fluid type, location, and thickness; retina and subretinal tissue complex thickness on OCT; size and lesion composition on FP and FA; and VA. Among 1185 CATT participants, 993 (84%) had fluid on OCT at baseline and completed 2 years of follow-up. At 2 years, intraretinal fluid (IRF), subretinal fluid (SRF), sub-retinal pigment epithelium (RPE) fluid, and subretinal tissue complex thickness decreased in all treatment groups. Ranibizumab monthly was best able to resolve each type of fluid. Eyes with SRF in the foveal center on OCT had better mean VA than eyes with no SRF (72.8 vs. 66.6 letters; P = 0.006). Eyes with IRF in the foveal center had worse mean VA than eyes without IRF (59.9 vs. 70.9 letters; P < 0.0001). Eyes with retinal thickness <120 μm had worse VA compared with eyes with retinal thickness 120 to 212 and >212 μm (59.4 vs. 71.3 vs. 70.3 letters; P < 0.0001). At 2 years, the mean VA (letters) of eyes varied substantially by the type of subfoveal pathology on FP and FA: 70.6 for no pathology; 74.1 for fluid only; 73.3 for CNV or pigment epithelial (RPE) detachment; 68.4 for nongeographic atrophy; and 62.9 for geographic atrophy, hemorrhage, RPE tear, or scar (P < 0.0001). The associations between VA and morphologic features identified through year 1 were maintained or strengthened during year 2. Eyes with foveal IRF, abnormally thin retina, greater thickness of the subretinal tissue complex on OCT, and subfoveal geographic atrophy or scar on FP/FA had the worst VA. Subretinal fluid was associated with better VA. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Characteristics and Ophthalmic Manifestations of the Classic Dengue Fever Epidemic in Singapore (2005-2006).

PubMed

Koh, Yan Tong; Sanjay, Srinivasan

2013-01-01

The aim of this study was to report the characteristics and ophthalmic manifestations associated with dengue fever (DF) in the 2005-2006 DF epidemic in Singapore. A retrospective case series. Eleven patients (7 males, 4 females) who were 14 to 40 years old (mean age, 27.3 years) with visual complaints occurring 1 to 2 weeks after the onset of DF underwent a complete ophthalmologic examination. The presenting visual acuity (VA) ranged from 6/6 to counting fingers. Five patients had bilateral eye involvement. Ophthalmic findings included retinal hemorrhages (15 eyes), cotton wool spots (15 eyes), retinal pigment epithelium alterations (5 eyes), optic disc swelling (3 eyes), foveolitis (3 eyes), and hyperemia (2 eyes). Impaired color vision was noted in 12 eyes. Visual field defects were noted in 13 eyes; 4 of these eyes were asymptomatic. Fundus fluorescein angiography was done in 9 patients; the findings include choroidal hyperfluorescence (9 eyes), blocked fluorescence (8 eyes), and capillary nonperfusion (1 eye). In 2 eyes, it was normal. Electrophysiology confirmed optic neuropathy in 3 eyes and maculopathy in 1 eye. The follow-up ranged from 12 days to 12 months. The VA at the last follow-up ranged from no light perception to 6/6. Visual field abnormalities were noted in 5 eyes despite a normal VA. Dengue fever is associated with a wide spectrum of ophthalmic manifestations. Rarely, ophthalmic complications in DF can result in permanent visual impairment. Further work can be done to elucidate the relationship between systemic and ocular manifestations of DF.

Veterans' Health Insurance Coverage Under the Affordable Care Act and Implications of Repeal for the Department of Veterans Affairs

PubMed Central

Dworsky, Michael; Farmer, Carrie M.; Shen, Mimi

2018-01-01

Abstract This article describes the Affordable Care Act's (ACA's) effects on nonelderly veterans' insurance coverage and demand for Department of Veterans Affairs (VA) health care and assesses the coverage and VA utilization changes that could result from repealing the ACA. Although prior research has shown that the number of uninsured veterans fell after the ACA took effect, the implications of ACA repeal for veterans and, especially, for VA have received less attention. Besides providing a new coverage option to veterans who are not enrolled in VA, the ACA also had the potential to affect health care use among VA patients. Findings include the following: In 2013, prior to the major coverage expansions under the ACA, nearly one in ten nonelderly veterans were uninsured, lacking access to both VA coverage and non-VA health insurance. Uninsurance among nonelderly veterans fell by an adjusted 36 percent (3.3 percentage points) after implementation of the ACA, from 9.1 percent in 2013 to 5.8 percent in 2015. By increasing non-VA health insurance coverage for VA patients, the ACA likely reduced demand for VA care; the authors estimate that, if the gains in insurance coverage that occurred between 2013 and 2015 had not occurred, nonelderly veterans would have used about 1 percent more VA health care in 2015: 125,000 more office visits, 1,500 more inpatient surgeries, and 375,000 more prescriptions. Recent congressional proposals to repeal and replace the ACA would increase the number of uninsured nonelderly veterans and further increase demand for VA health care. PMID:29607249

Surgical removal of subfoveal choroidal neovascularization in pathologic myopia: a 12-year follow-up study.

PubMed

Hera, R; Chiquet, C; Romanet, J P

2013-12-01

The purpose of this study was to review the 12-year visual outcomes of patients who underwent surgical removal for subfoveal choroidal neovascularization (CNV) attributable to pathologic myopia. This retrospective study included 14 patients, with a mean age of 45.8 years, high myopia (>6 D) and classic subfoveal CNV. They were treated with pars plana vitrectomy and surgical removal of CNV. All patients were followed up every 3 months for 2 years, with visual acuity (VA), fundus examination, and fluorescein angiography and then every year for 5 years. Ten patients underwent a final visit with VA and fundus examination after a minimum 12-year follow-up. The main outcome measurement was VA and the secondary outcome measurement was the lesion size. After 12 years of follow-up, the mean VA did not significantly change over time, with a mean gain of 0.22 logMAR at 1 year, and 0.18, 0.12 and 0.05 at 2, 5 and 12 years, respectively. The anatomical evolution was characterized by a significant enlargement of the lesion size at 5 years. This study showed that final VA after surgical treatment with 12 years of follow-up was poor, due to the significant CNV scar enlargement over time. These results should prompt a prospective randomized study of other medical treatments, particularly anti-vascular endothelial growth factor therapy.

Factors affecting the stability of visual function following cessation of occlusion therapy for amblyopia.

PubMed

Tacagni, Daniel J; Stewart, Catherine E; Moseley, Merrick J; Fielder, Alistair R

2007-06-01

To identify factors that predict which children with amblyopia are at greatest risk of regression of visual acuity (VA) following the cessation of occlusion therapy. A retrospective analysis was performed of 182 children (mean age at cessation of treatment; 5.9+/-1.6 years) who had undergone occlusion therapy for unilateral amblyopia, and had been followed up at least once within 15 months of cessation. Statistical analysis was used to identify whether change in VA following treatment cessation had any association with various factors, including the child's age, type of amblyopia, degree of anisometropia, initial severity of amblyopia, binocular vision status, length and dose of occlusion therapy, and VA response to treatment. At 1 year, follow-up from treatment cessation, children with "mixed" amblyopia (both anisometropia and strabismus) demonstrated significantly (p=0.03) greater deterioration in VA (0.11+/-0.11 log units) than children with only anisometropia (0.02+/-0.08 log units) or only strabismus (0.05+/-0.10 log units). However, none of the other factors investigated were found to be significant predictors. This study supports previous research that it is possible to identify those children most at risk of deterioration in VA following cessation of occlusion therapy. The presence of mixed amblyopia was the only risk factor identified in this study. Management of amblyopia should take this into account, with a more intensive follow-up recommended for those with both anisometropia and strabismus (mixed) amblyopia.

Relationship between binocular vision, visual acuity, and fine motor skills.

PubMed

O'Connor, Anna R; Birch, Eileen E; Anderson, Susan; Draper, Hayley

2010-12-01

The aims of this study were to analyze the relationship between the performance on fine motor skills tasks and peripheral and bifoveal sensory fusion, phasic and tonic motor fusion, the level of visual acuity (VA) in the poorer seeing eye, and the interocular VA difference. Subjects aged 12 to 28 years with a range of levels of binocular vision and VA performed three tasks: Purdue pegboard (number of pegs placed in 30 s), bead threading task (with two sizes of bead to increase the difficulty, time taken to thread a fixed number of beads), and a water pouring task (accuracy and time to pour a fixed quantity into five glass cylinders). Ophthalmic measures included peripheral (Worth 4 dot) and bifoveal (4 prism diopter) sensory fusion, phasic (prism bar) and tonic (Risley rotary prism) motor fusion ranges, and monocular VA. One hundred twenty-one subjects with a mean age of 18.8 years were tested; 18.2% had a manifest strabismus. Performance on fine motor skills tasks was significantly better in subjects with sensory and motor fusion compared with those without for most tasks, with significant differences between those with and without all measures of fusion on the pegboard and bead task. Both the acuity in the poorer seeing eye (highest r value of all motor tasks = 0.43) and the interocular acuity difference were statistically significantly related to performance on the motor skill tasks. Both sensory and motor fusion and good VA in both eyes are of benefit in the performance of fine motor skills tasks, with the presence of some binocular vision being beneficial compared with no fusion on certain sensorimotor tasks. This evidence supports the need to maximize fusion and VA outcomes.

Effects of multifocal soft contact lenses used to slow myopia progression on quality of vision in young adults.

PubMed

Kang, Pauline; McAlinden, Colm; Wildsoet, Christine F

2017-02-01

To assess the effects of multifocal soft contact lenses (MF SCLs) used for myopia control on visual acuity (VA) and subjective quality of vision. Twenty-four young adult myopes had baseline high and low-contrast VAs and refractions measured and quality of vision assessed by the Quality of Vision (QoV) questionnaire with single vision SCLs. Additional VA and QoV questionnaire data were collected immediately after subjects were fitted with Proclear MF SCLs and again after a 2-week adaptation period of daily lens wear. Data were collected for two MF SCL designs, incorporating +1.50 and +3.00 D peripheral near additions, with a week washout period allowed between the two lens trials. High- and low-contrast VAs were initially reduced with both MF SCL designs, but subsequently improved to be not significantly reduced in the case of high-contrast VA by the end of the 2-week adaptation period. The quality of vision was also reduced, more so with the +3.00 D MF SCL. Quality of Vision (QoV) scores describing frequency, severity and bothersome nature of visual symptoms indicated symptoms worsening rather than resolving over the 2-week period, particularly so with the +3.00 D MF SCL. Low and high add MF SCLs adversely affected vision on initial insertion, with sustained effects on low-contrast VA and QoV scores but not high-contrast VA. Thus, high-contrast VA is not a suitable surrogate for quality of vision. In prescribing MF SCLs for myopia control, clinicians should educate patients about these effects on vision. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Repeatability of Monocular Acuity Testing in Adults with and without Down Syndrome.

PubMed

Ravikumar, Ayeswarya; Benoit, Julia S; Morrison, Kelsie B; Marsack, Jason D; Anderson, Heather A

2018-03-01

Individuals with Down syndrome may experience greater difficulty reliably performing visual acuity (VA) tests because of intellectual disability and limitations in visual quality. This study evaluated the repeatability of acuity (Bailey-Lovie [BL] and HOTV) in subjects with and without Down syndrome. High-contrast VA was measured in both eyes of 30 subjects with Down syndrome (mean, 30 years; range, 18 to 50 years) and 24 control subjects without Down syndrome (mean, 29 years; range, 18 to 50 years). In the Down syndrome group, 23 subjects performed BL, and 7 subjects performed HOTV. All control subjects performed both BL and HOTV, but for HOTV analysis, only seven age-matched control subjects were included. For each eye, subjects performed VA three times on different charts (computer controlled, single-line display) until five total letters were missed on each chart. A repeated-measure ANOVA was used to compare the acuity measures between groups. The average logMAR VA for subjects with Down syndrome was approximately six lines worse than the control subjects (BL: Down syndrome = right eye: 0.51 ± 0.16, left eye: 0.53 ± 0.18; control = right eye: -0.06 ± 0.06, left eye: -0.06 ± 0.08, P < .0001; HOTV: Down syndrome = right eye: 0.47 ± 0.19, left eye: 0.46 ± 0.16; control: right eye = -0.11 ± 0.09, left eye: -0.07 ± 0.07, P < .001). Bailey-Lovie VA repeatability (1.96 * Sw * √2) was 0.13 logMAR (6.5 letters) for Down syndrome and 0.09 logMAR (4.5 letters) for control subjects. HOTV VA repeatability was 0.16 logMAR (eight letters) for both Down syndrome and control subjects. Despite poorer acuity in individuals with Down syndrome, repeatability of VA measurements was comparable to control subjects for both BL and HOTV techniques.

Visual Dysfunction and Associated Co-morbidities as Predictors of Mild Traumatic Brain Injury Seen Among Veterans in Non-VA Facilities: Implications for Clinical Practice.

PubMed

Urosevich, Thomas G; Boscarino, Joseph J; Hoffman, Stuart N; Kirchner, H Lester; Figley, Charles R; Adams, Richard E; Withey, Carrie A; Boscarino, Joseph A

2018-05-24

Traumatic brain injury (TBI) and post-traumatic stress disorder are considered the signature injuries of the Iraq and Afghanistan conflicts. With the extensive use of improvised explosive devices by the enemy, the concussive effects from blast have a greater potential to cause mild TBI (mTBI) in military Service Members. These mTBI can be associated with other physical and psychological health problems, including mTBI-induced visual processing and eye movement dysfunctions. Our study assessed if any visual dysfunctions existed in those surveyed in non-Veterans Administration (VA) facilities who had suffered mTBI (concussive effect), in addition to the presence of concussion-related co-morbidities. As part of a larger study involving veterans from different service eras, we surveyed 235 Veterans who had served during the Iraq and/or Afghanistan conflict era. Data for the study were collected using diagnostic telephone interviews of these veterans who were outpatients of the Geisinger Health System. We assess visual dysfunction in this sample and compare visual dysfunctions of those who had suffered a mTBI (concussive effect), as well as co-morbidities, with those in the cohort who had not suffered concussion effects. Of those veterans who experienced visual dysfunctions, our results reflected that the visual symptoms were significant for concussion with the subjects surveyed, even though all had experienced a mTBI event greater than five years ago. Although we did find an association with concussion and visual symptoms, the association for concussion was strongest with the finding of greater than or equal to three current TBI symptoms, therefore we found this to be the best predictor of previous concussion among the veterans. Veterans from the Iraq/Afghanistan era who had suffered concussive blast effects (mTBI) can present with covert visual dysfunction as well as additional physical and psychological health problems. The primary eye care providers, especially those in a non-military/VA facility, who encounter these veterans need to be aware of the predictors of mTBI, with the aim of uncovering visual dysfunctions and other associated co-morbidities.

Aflibercept, Bevacizumab, or Ranibizumab for Diabetic Macular Edema: Two-Year Results from a Comparative Effectiveness Randomized Clinical Trial.

PubMed

Wells, John A; Glassman, Adam R; Ayala, Allison R; Jampol, Lee M; Bressler, Neil M; Bressler, Susan B; Brucker, Alexander J; Ferris, Frederick L; Hampton, G Robert; Jhaveri, Chirag; Melia, Michele; Beck, Roy W

2016-06-01

To provide 2-year results comparing anti-vascular endothelial growth factor (VEGF) agents for center-involved diabetic macular edema (DME) using a standardized follow-up and retreatment regimen. Randomized clinical trial. Six hundred sixty participants with visual acuity (VA) impairment from DME. Randomization to 2.0-mg aflibercept, 1.25-mg repackaged (compounded) bevacizumab, or 0.3-mg ranibizumab intravitreous injections performed up to monthly using a protocol-specific follow-up and retreatment regimen. Focal/grid laser photocoagulation was added after 6 months if DME persisted. Visits occurred every 4 weeks during year 1 and were extended up to every 4 months thereafter when VA and macular thickness were stable. Change in VA, adverse events, and retreatment frequency. Median numbers of injections were 5, 6, and 6 in year 2 and 15, 16, and 15 over 2 years in the aflibercept, bevacizumab, and ranibizumab groups, respectively (global P = 0.08). Focal/grid laser photocoagulation was administered in 41%, 64%, and 52%, respectively (aflibercept vs. bevacizumab, P < 0.001; aflibercept vs. ranibizumab, P = 0.04; bevacizumab vs. ranibizumab, P = 0.01). At 2 years, mean VA improved by 12.8, 10.0, and 12.3 letters, respectively. Treatment group differences varied by baseline VA (P = 0.02 for interaction). With worse baseline VA (20/50 to 20/320), mean improvement was 18.1, 13.3, and 16.1 letters, respectively (aflibercept vs. bevacizumab, P = 0.02; aflibercept vs. ranibizumab, P = 0.18; ranibizumab vs. bevacizumab, P = 0.18). With better baseline VA (20/32 to 20/40), mean improvement was 7.8, 6.8, and 8.6 letters, respectively (P > 0.10, for pairwise comparisons). Anti-Platelet Trialists' Collaboration (APTC) events occurred in 5% with aflibercept, 8% with bevacizumab, and 12% with ranibizumab (global P = 0.047; aflibercept vs. bevacizumab, P = 0.34; aflibercept vs. ranibizumab, P = 0.047; ranibizumab vs. bevacizumab, P = 0.20; global P = 0.09 adjusted for potential confounders). All 3 anti-VEGF groups showed VA improvement from baseline to 2 years with a decreased number of injections in year 2. Visual acuity outcomes were similar for eyes with better baseline VA. Among eyes with worse baseline VA, aflibercept had superior 2-year VA outcomes compared with bevacizumab, but superiority of aflibercept over ranibizumab, noted at 1 year, was no longer identified. Higher APTC event rates with ranibizumab over 2 years warrants continued evaluation in future trials. Copyright © 2016 American Academy of Ophthalmology. All rights reserved.

Association Between Vessel Density and Visual Acuity in Patients With Diabetic Retinopathy and Poorly Controlled Type 1 Diabetes.

PubMed

Dupas, Bénédicte; Minvielle, Wilfried; Bonnin, Sophie; Couturier, Aude; Erginay, Ali; Massin, Pascale; Gaudric, Alain; Tadayoni, Ramin

2018-05-10

Capillary dropout is a hallmark of diabetic retinopathy, but its role in visual loss remains unclear. To examine how macular vessel density is correlated with visual acuity (VA) in patients younger than 40 years who have type 1 diabetes without macular edema but who have diabetic retinopathy requiring panretinal photocoagulation. Retrospective cohort study of VA and optical coherence tomography angiography data collected from consecutive patients during a single visit to Lariboisière Hospital, a tertiary referral center in Paris, France. The cohort included 22 eyes of 22 patients with type 1 diabetes without macular edema but with bilateral rapidly progressive diabetic retinopathy that was treated with panretinal photocoagulation between August 15, 2015, and December 30, 2016. Eyes were classified into 2 groups by VA: normal (logMAR, 0; Snellen equivalent, 20/20) and decreased (logMAR, >0; Snellen equivalent, <20/20). The control group included 12 eyes from age-matched healthy participants with normal vision. Visual acuity and mean vessel density in 4 retinal vascular plexuses: the superficial vascular plexus and the deep capillary complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Of the 22 participants, 11 (50%) were men, mean (SD) age was 30 (6) years, and mean (SD) hemoglobin A1c level was 8.9% (1.6%). Of the 22 eyes with diabetic retinopathy, 13 (59%) had normal VA and 9 (41%) had decreased VA (mean [SD]: logMAR, 0.12 [0.04]; Snellen equivalent, 20/25). Mean [SE] vessel density was lower for eyes with diabetic retinopathy and normal VA compared with the control group in the superficial vascular plexus (44.1% [0.9%] vs 49.1% [0.9%]; difference, -5.0% [1.3%]; 95% CI, -7.5% to -2.4%; P < .001), in the deep capillary complex (44.3% [1.2%] vs 50.6% [1.3%]; difference, -6.3% [1.8%]; 95% CI, -9.9% to -2.7%; P = .001), in the intermediate capillary plexus (43.8% [1.2%] vs 49.3% [1.2%]; difference, -5.5% [1.7%]; 95% CI, -9.0% to -2.0%; P = .003), and in the deep capillary plexus (24.5% [1.0%] vs 30.5% [1.0%]; difference, -6.1% [1.4%]; 95% CI, -8.9% to -3.2%; P < .001). Mean vessel density was lower in eyes with diabetic retinopathy and decreased VA compared with eyes with diabetic retinopathy and normal VA; the mean (SE) loss was more pronounced in the deep capillary complex (34.6% [1.5%] vs 44.3% [1.2%]; difference, -9.6% [1.9%]; 95% CI, -13.6% to -5.7%; P < .001), especially in the deep capillary plexus (15.2% [1.2%] vs 24.5% [1.0%]; difference, -9.3% [1.5%]; 95% CI, -12.4% to -6.1%; P < .001), than in the superficial vascular plexus (39.6% [1.1%] vs 44.1% [0.9%]; difference, -4.5% [1.4%]; 95% CI, -7.3% to -1.7%; P = .002). These data suggest that in patients with type 1 diabetes without macular edema but with severe nonproliferative or proliferative diabetic retinopathy, decreased VA may be associated with the degree of capillary loss in the deep capillary complex.

E-Readers Are More Effective than Paper for Some with Dyslexia

PubMed Central

Schneps, Matthew H.; Thomson, Jenny M.; Chen, Chen; Sonnert, Gerhard; Pomplun, Marc

2013-01-01

E-readers are fast rivaling print as a dominant method for reading. Because they offer accessibility options that are impossible in print, they are potentially beneficial for those with impairments, such as dyslexia. Yet, little is known about how the use of these devices influences reading in those who struggle. Here, we observe reading comprehension and speed in 103 high school students with dyslexia. Reading on paper was compared with reading on a small handheld e-reader device, formatted to display few words per line. We found that use of the device significantly improved speed and comprehension, when compared with traditional presentations on paper for specific subsets of these individuals: Those who struggled most with phoneme decoding or efficient sight word reading read more rapidly using the device, and those with limited VA Spans gained in comprehension. Prior eye tracking studies demonstrated that short lines facilitate reading in dyslexia, suggesting that it is the use of short lines (and not the device per se) that leads to the observed benefits. We propose that these findings may be understood as a consequence of visual attention deficits, in some with dyslexia, that make it difficult to allocate attention to uncrowded text near fixation, as the gaze advances during reading. Short lines ameliorate this by guiding attention to the uncrowded span. PMID:24058697

Outcomes of presbyopia-correcting intraocular lenses after laser in situ keratomileusis.

PubMed

Chow, Sharon S W; Chan, Tommy C Y; Ng, Alex L K; Kwok, Alvin K H

2018-03-28

Laser in situ keratomileusis (LASIK) is the most common refractive surgery in young patients, which aims at providing a clear distance vision without the use of spectacles. With time, these patients develop symptomatic cataract, which affects activities of daily living, and to improve visual acuity, intraocular lens (IOL) implantation can be considered. In post-myopic LASIK patients, to allow continuation of spectacle independence, the implantation of presbyopia-correcting IOLs is a suitable option. The purpose of this retrospective case series is to report the visual outcome and quality in post-myopic LASIK eyes after the implantation of AT LISA tri839MP IOL. Twenty eyes of 13 patients with history of myopic LASIK within 20 years underwent phacoemulsification by one single surgeon. All eyes were implanted with AT LISA tri839PMP IOL, and their outcomes were evaluated at 6 months postoperation. The mean postoperative uncorrected distance visual acuity (VA) is 0.28 ± 0.29, while the corrected distance VA is 0.06 ± 0.14. The mean postoperative uncorrected near VA is 0.02 ± 0.05, while the corrected near VA is 0.01 ± 0.02. The mean postoperative manifest refraction spherical equivalent (SE) is - 0.92 ± 0.76D. There is a statistically significant difference between the preoperative and postoperative refraction (p = 0.02), which shows a postoperative myopic shift. There is also a statistically significant difference between the mean targeted SE and postoperative manifest refraction SE (p = 0.00). Only one out of 20 eyes (5%) reported halo and glare symptoms. Ten out of 20 eyes (50%) are able to achieve spectacles independence. In conclusion, in post-myopic LASIK eyes, AT LISA tri839MP provides a good visual outcome at both near and distance, but is more predictable at near than at distance. There is a myopic shift in the postoperative SE. Visual quality is satisfactory and has not been exacerbated. Most patients can remain to be spectacles free at all distances.

Visual Function of Moderately Hyperopic 4- and 5-Year-Old Children in the Vision In Preschoolers - Hyperopia In Preschoolers Study

PubMed Central

Ciner, Elise B.; Kulp, Marjean Taylor; Maguire, Maureen; Pistilli, Maxwell; Candy, T. Rowan; Moore, Bruce; Ying, Gui-shuang; Quinn, Graham; Orlansky, Gale; Cyert, Lynn

2016-01-01

Purpose To compare visual performance between emmetropic and uncorrected moderately hyperopic preschool age children without strabismus or amblyopia. Design Cross-sectional study. Methods Setting Multicenter, institutional. Patient or Study Population Children aged 4 or 5 years. Intervention or Observation Procedures Visual functions were classified as normal or reduced for each child based on the 95% confidence interval for emmetropes. Hyperopic (≥3.0 diopters [D] to ≤6.0D in the most hyperopic meridian; astigmatism≤1.50D; anisometropia≤1.0D) and emmetropic status were determined by cycloplegic autorefraction. Main Outcome Measures Uncorrected monocular distance and binocular near visual acuity (VA); accommodative response; and near random dot stereoacuity. Results Mean (±SD) LogMAR distance VA among 248 emmetropes was better than among 244 hyperopes for the better (0.05±0.10 vs. 0.14±0.11, p<.001) and worse eyes (0.10±0.11 vs. 0.19±0.10, p<.001). Mean binocular LogMAR near VA was better in emmetropes than hyperopes (0.13±0.11 vs. 0.21±0.11, p<.001). Mean accommodative response for emmetropes was lower than for hyperopes for both Monocular Estimation Method (1.03±0.51D vs. 2.03±1.03D, p<0.001) and Grand Seiko (0.46±0.45D vs. 0.99±1.0D, p<0.001). Median near stereoacuity was better in emmetropes than hyperopes (40 sec arc vs.120 sec arc, p<0.001). The average number of reduced visual functions was lower in emmetropic than in hyperopic children (.19 vs.1.0 p<0.001). Conclusions VA, accommodative response, and stereoacuity were significantly reduced in moderate uncorrected hyperopic preschool children compared to emmetropes. Higher hyperopes (≥4 to ≤6D) were at greatest risk, although more than half of children with lower magnitudes (≥3 to <4D) demonstrated one or more reductions in function. PMID:27477769

Evaluating refraction and visual acuity with the Nidek autorefractometer AR-360A in a randomized population-based screening study.

PubMed

Stoor, Katri; Karvonen, Elina; Liinamaa, Johanna; Saarela, Ville

2017-11-30

The evaluation of visual acuity (VA) and refraction in the Northern Finland Birth Cohort Eye study was performed using the Nidek AR-360A autorefractometer. The accuracy of the method for this population-based screening study was assessed. Measurements of the refractive error were obtained from the right eyes of 1238 subjects (mean age 47), first objectively with the AR-360A and then subjectively by an optometrist. Agreement with the subjective refraction was calculated for sphere, cylinder, mean spherical equivalent (MSE), cylindrical vectors J 45 and J 0 and presbyopic correction (add). Visual acuity (VA) was measured using an ETDRS chart and the autorefractometer. The refractive error measured with the AR-360A was higher than the subjective refraction performed by the optometrist for sphere (0.007 D ± 0.24 D p = 0.30) and also for cylinder (-0.16 D ± 0.20 D p < 0.0005). The bias between the measurements of MSE, J 45 and J 0 was low: -0.07 D ± 0.22 D (p = 0.002), 0.01 D ± 0.43 D (p = 0.25) and -0.01 D ± 0.42 D (p = 0.43), respectively. The amount of add measured by the autorefractometer was higher than the subjective 0.35 D ± 0.29 D (p < 0.0005). There was a statistically significant correlation between VA (p < 0.0005) and the difference between the subjective and objective refraction. In 99.2% of the measurements, visual values were within one decimal line of each other. The Nidek AR-360A autorefractometer is an accurate tool for determining the refraction and VA in a clinical screening trial. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Hyperopia and emergent literacy of young children: pilot study.

PubMed

Shankar, Sunita; Evans, Mary Ann; Bobier, William R

2007-11-01

To compare emergent literacy skills in uncorrected hyperopic and emmetropic children. "Hyperopes" (>or=2.00 D sphere along the most hyperopic meridian; n=13; aged 67+/-13 mo) and "emmetropes" (

Economic Evaluation of Low-Vision Rehabilitation for Veterans With Macular Diseases in the US Department of Veterans Affairs.

PubMed

Stroupe, Kevin T; Stelmack, Joan A; Tang, X Charlene; Wei, Yongliang; Sayers, Scott; Reda, Domenic J; Kwon, Ellen; Massof, Robert W

2018-05-01

Examining costs and consequences of different low-vision (LV) programs provides important information about resources needed to expand treatment options efficiently. To examine the costs and consequences of LV rehabilitation or basic LV services. The US Department of Veterans Affairs (VA) Low Vision Intervention Trial (LOVIT) II was conducted from September 27, 2010, to July 31, 2014, at 9 VA facilities and included 323 veterans with macular diseases and a best-corrected distance visual acuity of 20/50 to 20/200. Veterans were randomized to receive basic LV services that provided LV devices without therapy, or LV rehabilitation that added a therapist to LV services who provided instruction and homework on using LV devices, eccentric viewing, and environmental modification. We compared costs and consequences between these groups. Low-vision devices without therapy and LV devices with therapy. Costs of providing basic LV services or LV rehabilitation were assessed. We measured consequences as changes in functional visual ability from baseline to follow-up 4 months after randomization using the VA Low Vision Visual Functioning Questionnaire. Visual ability was measured in dimensionless log odds units (logits). Of 323 randomized patients, the mean (SD) age was 80 (10.5) years, 314 (97.2%) were men, and 292 (90.4%) were white. One hundred sixty (49.5%) received basic LV services and 163 (50.1%) received LV rehabilitation. The mean (SD) total direct health care costs per patient were similar between patients who were randomized to receive basic LV services ($1662 [$671]) or LV rehabilitation ($1788 [$864]) (basic LV services, $126 lower; 95% CI, $299 lower to $35 higher; P = .15). However, basic LV services required less time and had lower transportation costs. Patients receiving LV rehabilitation had greater improvements in overall visual ability, reading ability, visual information processing, and visual motor skill scores.

Reliability of visual acuity measurements taken with a notebook and a tablet computer in participants who were illiterate to Roman characters.

PubMed

Ruamviboonsuk, Paisan; Sudsakorn, Napitchareeya; Somkijrungroj, Thanapong; Engkagul, Chayanee; Tiensuwan, Montip

2012-03-01

Electronic measurement of visual acuity (VA) has been proposed and adopted as a method of determining VA scores in clinical research. Characters (optotypes) are displayed on a monitor screen and the examinee selects a match and inputs his choice to another electronic device. Unfortunately, the optotypes, called Sloan letters, in the standard protocol are 10 Roman characters. This limits their practicabilityfor measuring VA of patients who are illiterate to these characters. The authors introduced a method of displaying the Sloan letters one by one on a notebook and all 10 Sloan letters on a tablet computer screen. The former is for testing the patients whereas the latter is for them to input their responses by tapping on a letter that matches the one on the notebook screen. To assess test-retest reliability of VA scores determined with this method. Participants without ocular abnormality were recruited to have their right eyes measured with the same VA measurement method twice, one week apart. Those who were illiterate to Roman characters were enrolled for the aforementioned method for measuring their VA (Tablet group). A 15-inch display notebook computer and a 9-inch display tablet computer (iPad) communicated via a local wireless data network provided by a Wi-Fi router. Those who understood Roman characters were enrolled to have measurements with a 17-inch desktop computer and an infrared wireless keyboard (Keyboard group). Both methods used the same protocols and software for VA measurements. Reliability of VA scores obtained from each group was assessed by the confidence interval (CI) of the difference of the scores from the test and retest. The t test was used to analyze differences in mean VA scores between the test and retest in each group with p < 0.05 determined as statistically significant. There were 49 and 50 participants in the Tablet and Keyboard group respectively. The 95% CI of the difference between the scores from the test and retest in each group was 2 letters. Approximately 95% of participants in each group had an absolute difference of the scores between the test and retest of 7 letters. The mean of VA scores from the first test was significantly different from that of the second test in the Keyboard group (one-letter difference, p = 0.049); there was no significant difference between these scores in the Tablet group (0.1-letter difference, p = 0.86). Tablet computers may be used to assist patients who are illiterate to Roman characters in having their VA measured with the standard electronic protocol. This preliminary study suggested that the proposed method should be useful for reliable measuring VA outcome in multicenter international clinical trials without encountering a language barrier

Characterizing Disease Burden and Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration.

PubMed

Chakravarthy, Usha; Bailey, Clare C; Johnston, Robert L; McKibbin, Martin; Khan, Rehna S; Mahmood, Sajjad; Downey, Louise; Dhingra, Narendra; Brand, Christopher; Brittain, Christopher J; Willis, Jeffrey R; Rabhi, Sarah; Muthutantri, Anushini; Cantrell, Ronald A

2018-06-01

To understand levels of disease burden and progression in a real-world setting among patients from the United Kingdom with bilateral geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Retrospective cohort analysis of a multicenter electronic medical record (EMR) database. Patients who were aged ≥50 years with bilateral GA and no history of choroidal neovascularization (CNV) and who attended 1 of 10 clinical sites using the EMR. A deidentified data set was constructed from the records held at the 10 sites. An algorithm was used to extract cases with a GA diagnosis, of which 1901 had bilateral GA and form the basis of this report. A sample of records randomly selected from each center was used to validate disease definitions. Progression to blindness (visual acuity [VA] <20 letters or Snellen 3/60 in the better-seeing eye), driving ineligibility (VA ≤70 letters or Snellen 6/12 in the better-seeing eye), progression to CNV, loss of 10 or more letters, and mean change in VA over time. At first record of GA, 7.1% had a VA in the better-seeing eye equal to or lower than the cutoff for blindness registration and 71.1% had a VA that would have rendered them ineligible to drive. Over time, 16% became legally blind (median time to outcome, 6.2 years) and 66.7% became ineligible to drive (median time to outcome, 1.6 years). In the worse-seeing eye, 40.1% lost ≥10 letters in 2.4 years. Among patients with baseline and 24-month VA measurements, mean VA decline was 6.1 letters in the worse-seeing eye (n = 413) and 12.4 letters in the better-seeing eye (n = 414). The rate of progression to CNV in either eye was 7.4% per patient-year. At initial diagnosis, based on VA in the better-seeing eye, a high proportion of patients with bilateral GA were ineligible to drive and approximately 7% were eligible for UK blindness registration. The subsequent reduction in VA that occurred in the better-seeing eye would render a further two-thirds ineligible to drive. These findings emphasize the severity of the visual disability associated with GA secondary to AMD. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

[National survey of blindness and avoidable visual impairment in Honduras].

PubMed

Alvarado, Doris; Rivera, Belinda; Lagos, Luis; Ochoa, Mayra; Starkman, Ivette; Castillo, Mariela; Flores, Eduardo; Lansingh, Van C; Limburg, Hans; Silva, Juan Carlos

2014-11-01

To determine the prevalence of blindness and visual impairment in Honduras, its causes and the response by the health services to growing demand. A cross-sectional population study was conducted between June and December 2013 using the standard methodology of the Rapid Assessment of Avoidable Blindness. A random sample survey was done in 63 clusters of 50 individuals aged ≥ 50, representative of the country as a whole. Visual acuity (VA) was assessed using a Snellen eye chart, and the condition of the lens and posterior pole was examined by direct ophthalmoscopy. Cataract surgical coverage was calculated and an assessment made of its quality, the causes of VA < 20/60 and the barriers to accessing surgical treatment. A total of 2 999 people were examined (95.2% of the forecast total). Blindness prevalence was 1.9% (confidence interval of 95%: 1.4-2.4%) and 82.2% of these cases were avoidable. The main causes of blindness were unoperated cataracts (59.2%) and glaucoma (21.1%). Uncorrected refraction error was the main cause of severe (19.7%) and moderate (58.6%) visual impairment. Cataract surgical coverage was 75.2%. 62.5% of the eyes operated for cataracts achieved a VA > 20/60 with available correction. The main barriers against cataract surgery were cost (27.7%) and the lack of availability or difficulty of geographical access to the treatment (24.6%). The prevalence of blindness and visual impairment in Honduras is similar to that of other Latin American countries. 67% of cases of blindness could be resolved by improving the response capacity of the ophthalmological services, especially of cataract surgery, improving optician services and incorporating eye care in primary health care.

Visual Impairment and Blindness Avoided with Ranibizumab in Hispanic and Non-Hispanic Whites with Diabetic Macular Edema in the United States.

PubMed

Varma, Rohit; Bressler, Neil M; Doan, Quan V; Danese, Mark; Dolan, Chantal M; Lee, Abraham; Turpcu, Adam

2015-05-01

To estimate visual impairment (VI) and blindness avoided with intravitreal ranibizumab 0.3 mg treatment for central-involved diabetic macular edema (DME) among Hispanic and non-Hispanic white individuals in the United States. Population-based model simulating visual acuity (VA) outcomes over 2 years after diagnosis and treatment of DME. Visual acuity changes with and without ranibizumab were based on data from the RISE, RIDE, and DRCR Network trials. For the better-seeing eye, VA outcomes included VI, defined as worse than 20/40 in the better-seeing eye, and blindness, defined as VA of 20/200 or worse in the better-seeing eye. Incidence of 1 or both eyes with central-involved DME in 2010 were estimated based on the 2010 United States population, prevalence of diabetes mellitus, and 1-year central-involved DME incidence rate. Sixty-one percent of incident individuals had bilateral DME and 39% had unilateral DME, but DME could develop in the fellow eye. Cases of VI and blindness avoided with ranibizumab treatment. Among approximately 102 million Hispanic and non-Hispanic white individuals in the United States 45 years of age and older in 2010, an estimated 37 274 had central-involved DME and VI eligible for ranibizumab treatment. Compared with no ranibizumab treatment, the model predicted that ranibizumab 0.3 mg every 4 weeks would reduce the number of individuals with VI from 11 438 (95% simulation interval [SI], 7249-16 077) to 6304 (95% SI, 3921-8981), a 45% (95% SI, 36%-53%) reduction at 2 years. Ranibizumab would reduce the number of incident eyes with VA worse than 20/40 from 16 910 (95% SI, 10 729-23 577) to 9361 (95% SI, 5839-13 245), a 45% (95% SI, 38%-51%) reduction. Ranibizumab was estimated to reduce the number of individuals with legal blindness by 75% (95% SI, 58%-88%) and the number of incident eyes with VA of 20/200 or worse by 76% (95% SI, 63%-87%). This model suggests that ranibizumab 0.3 mg every 4 weeks substantially reduces prevalence of VI and legal blindness 2 years after initiating treatment among Hispanic and non-Hispanic white individuals in the United States with central-involved DME that has caused vision loss. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Refractive errors and cataract as causes of visual impairment in Brazil.

PubMed

Eduardo Leite Arieta, Carlos; Nicolini Delgado, Alzira Maria; José, Newton Kara; Temporini, Edméia Rita; Alves, Milton Ruiz; de Carvalho Moreira Filho, Djalma

2003-02-01

To identify the main causes of visual impairment (VA

Screening for refractive error among primary school children in Bayelsa state, Nigeria

PubMed Central

Opubiri, Ibeinmo; Pedro-Egbe, Chinyere

2013-01-01

Introduction Vision screening study in primary school children has not been done in Bayelsa State. This study aims to screen for refractive error among primary school children in Bayelsa State and use the data to plan for school Eye Health Program. Methods A cross sectional study on screening for refractive error in school children was carried out in Yenagoa Local Government Area of Bayelsa State in June 2009. A multistage sampling technique was used to select the study population (pupils aged between 5-15 years). Visual acuity (VA) for each eye, was assessed outside the classroom at a distance of 6 meters. Those with VA ≤6/9 were presented with a pinhole and the test repeated. Funduscopy was done inside a poorly lit classroom. An improvement of the VA with pinhole was considered refractive error. Data was analyzed with EPI INFO version 6. Results A total of 1,242 school children consisting of 658 females and 584 males were examined.About 97.7% of pupils had normal VA (VA of 6/6) while 56 eyes had VAs ≤ 6/9. Of these 56 eyes, the visual acuity in 49 eyes (87.5%) improved with pinhole. Twenty seven pupils had refractive error, giving a prevalence of 2.2%. Refractive error involved both eyes in 22 pupils (81.5%) and the 8-10 years age range had the highest proportion (40.7%) of cases of refractive error followed by the 9-13 year-old age range (37%). Conclusion The prevalence of refractive error was 2.2% and most eyes (97.7%) had normal vision. PMID:23646210

Baseline traits of low vision patients served by private outpatient clinical centers in the United States.

PubMed

Goldstein, Judith E; Massof, Robert W; Deremeik, James T; Braudway, Sonya; Jackson, Mary Lou; Kehler, K Bradley; Primo, Susan A; Sunness, Janet S

2012-08-01

To characterize the traits of low vision patients who seek outpatient low vision rehabilitation (LVR) services in the United States. In a prospective observational study, we enrolled 764 new low vision patients seeking outpatient LVR services from 28 clinical centers in the United States. Before their initial appointment, multiple questionnaires assessing daily living and vision, physical, psychological, and cognitive health states were administered by telephone. Baseline clinical visual impairment measures and disorder diagnoses were recorded. Patients had a median age of 77 years, were primarily female (66%), and had macular disease (55%), most of which was nonneovascular age-related macular degeneration. More than one-third of the patients (37%) had mild vision impairment with habitual visual acuity (VA) of 20/60 or greater. The VA correlated well with contrast sensitivity (r = -0.52) but poorly with self-reported vision quality. The intake survey revealed self-reported physical health limitations, including decreased endurance (68%) and mobility problems (52%). Many patients reported increased levels of frustration (42%) and depressed mood (22%); memory and cognitive impairment (11%) were less frequently endorsed. Patients relied on others for daily living support (87%), but many (31%) still drove. Most patients seeking LVR are geriatric and have macular disease with relatively preserved VA. The disparity between VA and subjective quality of vision suggests that LVR referrals are based on symptoms rather than on VA alone. Patients seen for LVR services have significant physical, psychological, and cognitive disorders that can amplify vision disabilities and decrease rehabilitation potential.

The role of vision in academic school performance.

PubMed

Dirani, Mohamed; Zhang, Xiaoe; Goh, Liang Ke; Young, Terri L; Lee, Paul; Saw, Seang Mei

2010-01-01

To determine whether presenting distance visual acuity is related to subsequent academic school performance in Singaporean children between 9 to 10 years of age. Singapore children (n = 1143 children) were examined during their visits at ages 9 to 10 years (grades 3 to 4) as part of the Singapore Cohort Study of the Risk Factors for Myopia (SCORM) longitudinal study. Each child underwent an annual comprehensive eye examination, including the assessment of presenting logarithm of the minimum angle of resolution (LogMAR) distance visual acuity (VA). The individual marks of a nation-wide standard examination in grade 4 were used as the outcome measure for academic school performance. Children with any known eye disease, (such as media opacities) were excluded from the analysis. The mean presenting distance VA of the better eye was 0.10 and 0.08 when the children were in grades 3 and 4, respectively. There was a statistically significant difference for mean presenting VA with 9 and 10 year old boys scoring better (0.08 and 0.07) compared to girls (0.12 and 0.09) for the same ages, (p = 0.001 and p = 0.007), respectively. After adjusting for gender, ethnicity, school, reading, intelligence quotient and father's education, no significant relationships were found between average examination marks at the end of grade 4 and presenting VA obtained (better eye and worst eye) in grade 3 (p = 0.38 and p = 0.98) and 4 (p = 0.27 and p = 0.16). In our sample of Singaporean children without ocular disease, distance VA did not play a significant role in predicting academic school performance.

Association between characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab for diabetic macular edema.

PubMed

Murakami, Tomoaki; Suzuma, Kiyoshi; Uji, Akihito; Yoshitake, Shin; Dodo, Yoko; Fujimoto, Masahiro; Yoshitake, Tatsuya; Miwa, Yuko; Yoshimura, Nagahisa

2018-05-01

To investigate the association between the characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab treatment for diabetic macular edema (DME) at 3 months from the initial injection. We retrospectively reviewed 66 eyes of 61 patients with center-involved DME who received three consecutive ranibizumab injections and following as-needed administrations. We evaluated the relationship between visual improvement at 3 months and the preoperative optical coherence tomography (OCT) parameters including hyperreflective foci, heterogeneous OCT reflectivity, mean levels of OCT reflectivity and height of foveal cystoid spaces. Twenty-three eyes without preoperative hyperreflective foci in the foveal cystoid spaces had significantly greater improvement in the logarithm of the minimum angle of resolution visual acuity (logMAR VA) at 3 months than 43 eyes with foci (P = 0.006). That was similar to the greater reduction in CSF thickness in eyes without lesions after treatment at the same time point (P < 0.001). VA improvement at 3 months was not associated with the height (R = 0.215, P = 0.083) or the reflectivity levels (R = -0.079, P = 0.538) of foveal cystoid spaces. There were no differences in VA changes between eyes with and without heterogeneous reflectivity in foveal cystoid spaces (P = 0.297). Multivariate analyses showed that logMAR VA and the absence of hyperreflective foci in foveal cystoid spaces were associated with VA improvement at 3 months. Hyperreflective foci in foveal cystoid spaces at baseline predict poorer short-term responsiveness to ranibizumab injections for DME.

Does compliance with amblyopia management improve following supervised occlusion treatment?

PubMed

El-Ghrably, I A; Longville, D; Gnanaraj, L

2007-01-01

To demonstrate improvement in compliance following supervised occlusion therapy for amblyopia in children who had failed to respond to outpatient treatment. Retrospective review of the visual outcome of 30 children who were admitted to an ophthalmology ward for 1-day intensive supervised occlusion. These children had documented poor compliance and previously failed to respond to the outpatient occlusion treatment. During their stay a trained ophthalmology nurse educated parents regarding amblyopia and the benefits of occlusion therapy. Visual acuity (VA) of the amblyopic and fellow eyes was recorded on admission, discharge, and at each subsequent visit. The compliance was recorded from parent's history and also indirectly by noticing improvement in vision. The mean supervised occlusion was 7.4 hours (range 4-12 hours). The compliance with occlusion therapy improved in 23 children (77%) after discharge. The mean duration of occlusion after discharge improved to 4 hours (range 1-12 hours). The mean follow-up was 18 months (range 4-24 months). Though there was no dramatic improvement in VA at discharge there was a statistically significant improvement in VA between admission and last recorded VA (p<0.0001). Of the 23 children who were compliant with occlusion following discharge, 21 (91%) gained at least one line of acuity in their amblyopic eye on the last assessment of their VA and five of them achieved 6/12. Of the seven children who did not comply with occlusion following discharge, only one patient gained one line improvement in his amblyopic eye. This study shows that supervised occlusion treatment and parental education was effective in children who had initially failed traditional outpatient treatment.

DSAEK: practical approach to choose the microkeratome head on the basis of donor cornea pachymetry.

PubMed

Wisse, Robert P L; Achterberg, Jens A; Van der Lelij, Allegonda

2014-03-01

The aim of this study was to supply data on the relationship between Descemet stripping automated endothelial keratoplasty (DSAEK) graft thickness and its effects on visual acuity (VA), pace of visual recovery, endothelial cell densities (ECDs), and surgical complications. We additionally provide an approach for choosing the microkeratome blade thickness when multiple patients are scheduled for DSAEK. This is a retrospective analysis of all DSAEK procedures performed at our institute from January 2011 to December 2012. The VA was assessed at all postop visits. The ECD was assessed at 6 and 12 months postoperatively. An algorithm based on donor cornea pachymetry was used to assist in the choice of a microkeratome blade either 350 or 400 μm thick. Two groups were created on the basis of the microkeratome blade chosen. Outcomes were given per treatment group. One hundred two consecutive DSAEK procedures were performed; 60 grafts were prepared with the 350-μm blade and 39 with the 400-μm blade. Baseline characteristics did not differ materially. Grafts dissected using the 350-μm knife were significantly thicker than the grafts dissected with the 400-μm blade, with values of 257 ± 47 μm and 222 ± 33 μm, respectively (P = 0.01). The pace of visual recovery, VA at maximum follow-up, and ECD did not differ significantly between groups. Surgical complications were evenly distributed over both groups. This study indicates that using neither the 350-μm nor 400-μm microkeratome blade for the DSAEK altered the outcomes in terms of VA, ECD, and surgical complications. The algorithm presented in this study is helpful in equally distributing benefits from thinner grafting for all DSAEK-operated patients.

Axis-free correction of astigmatism using bifocal soft contact lenses.

PubMed

Leube, Alexander; Kovats, Imre; Wahl, Siegfried; Sickenberger, Wolfgang

2017-12-01

Pilot study to investigate the feasibility of an axis-free correction approach of regular astigmatism using soft, bifocal contact lenses (CL). The investigation covers an optical simulation and a pilot study for the assessment of visual performance (over refraction OR, monocular visual acuity VA). The power of the two zones was adjusted according to the power of the astigmatic meridians, individually. Subjective performance was assessed in 30 participants with a mean horizontal cylindrical component of J 0 =- 0.65±1.29 D (cylinder from -0.75 to -4.00 DC). OR and VA were measured directly after fitting the CL, after one hour and after 5days (3FUP). Evaluating the modulation transfer function, CL increased the Strehl ratio by 10% and the transferred spatial frequency was improved from 6.6 cpd to 21.3 cpd. Analysis of Sturm's interval revealed a residual astigmatism of D Ast =0.73 D. OR revealed a statistically significant reduction of spherical error between baseline and all follow up (ΔM=-2.14 D, p<0.001) and between the J 0 from baseline to 3FUP (ΔJ 0 =-0.46 D, p=0.04). Wearing the CL for 5days did not result in a significant difference of VA (ΔVA 3FUP =+0.01 logMAR, p=0.99). Axis-free correction of astigmatism using bifocal CL resulted in reasonable performance based on computer simulation. Participants showed no clinically reduced visual acuity or contrast sensitivity. Further clinical studies are needed to show if this approach provides a good alternative to conventional astigmatic correction. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cat-scratch disease: ocular manifestations and treatment outcome.

PubMed

Habot-Wilner, Zohar; Trivizki, Omer; Goldstein, Michaella; Kesler, Anat; Shulman, Shiri; Horowitz, Josepha; Amer, Radgonde; David, Ran; Ben-Arie-Weintrob, Yael; Bakshi, Erez; Almog, Yehoshua; Sartani, Gil; Vishnevskia-Dai, Vicktoria; Kramer, Michal; Bar, Asaf; Kehat, Rinat; Ephros, Moshe; Giladi, Michael

2018-03-05

To characterize cat-scratch disease (CSD) ocular manifestations and visual outcome and evaluate the effect of systemic antibiotics and corticosteroids on final visual acuity (VA). Multicentre retrospective cohort study. Medical records of 86 patients with ocular disease (107 eyes) of 3222 patients identified in a national CSD surveillance study were reviewed. Mean age was 35.1 ± 14.2 years. Median follow-up was 20 weeks (range 1-806 weeks). Of 94/107 (88%) eyes with swollen disc, 60 (64%) had neuroretinitis at presentation, 14 (15%) developed neuroretinitis during follow-up, and 20 (21%) were diagnosed with inflammatory disc oedema. Optic nerve head lesion, uveitis, optic neuropathy and retinal vessel occlusion were found in 43 (40%), 38 (36%), 34 (33%) and 8 (7%) eyes, respectively. Good VA (better than 20/40), moderate vision loss (20/40-20/200) and severe vision loss (worse than 20/200) were found in 26/79 (33%), 35/79 (44%) and 18/79 (23%) eyes at baseline and in 63/79 (80%), 11/79 (14%) and 5/79 (6%) eyes at final follow-up, respectively (p < 0.001). Significant VA improvement (defined as improvement of ≥3 Snellen lines at final follow-up compared to baseline) occurred in 12/24 (50%) eyes treated with antibiotics compared with 14/16 (88%) eyes treated with antibiotics and corticosteroids (p = 0.02). Multivariate logistic regression was suggestive of the same association (odds ratio 7.0; 95% CI 1.3-37.7; p = 0.024). Optic nerve head lesion is a common and unique manifestation of ocular CSD. Most patients improved and had final good VA. Combined antibiotics and corticosteroid treatment was associated with a better visual outcome. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Post-lens tear turbidity and visual quality after scleral lens wear.

PubMed

Carracedo, Gonzalo; Serramito-Blanco, Maria; Martin-Gil, Alba; Wang, Zicheng; Rodriguez-Pomar, Candela; Pintor, Jesús

2017-11-01

The aim was to evaluate the turbidity and thickness of the post-lens tear layer and its effect on visual quality in patients with keratoconus after the beginning of lens wear and before lens removal at the end of eight hours. Twenty-six patients with keratoconus (aged 36.95 ± 8.95 years) participated voluntarily in the study. The sample was divided into two groups: patients with intrastromal corneal ring (ICRS group) and patients without ICRS (KC group). Distance visual acuity (VA), contrast sensitivity, pachymetry, post-lens tear layer height and post-lens tear layer turbidity (percentage area occupied and number of particles per mm 2 ) were evaluated with optical coherence tomography before and after wearing a scleral lens. A significant increase of turbidity was found in all groups assessed (p < 0.05). The number of particles per square millimetre was eight times higher after scleral lens wear than at the beginning of wearing the lens for all groups. VA decreases in all groups after scleral lens wear (p < 0.001). All patients showed a statistical diminishing of contrast sensitivity after scleral lens wear (p < 0.05). A significant correlation was found for both turbidity parameters with distance VA but no correlation between turbidity and post-lens tear layer thickness at the beginning was found (p > 0.05). A strong correlation in all groups between the post-lens tear layer at the beginning and differences of tear layer thickness between two measures was also found (p < 0.05). The VA decrease during the scleral lens wearing, filled with preserved saline solution, was due to the increasing post-lens tear layer turbidity. © 2017 Optometry Australia.

Vision of low astigmats through thick and thin lathe-cut soft contact lenses.

PubMed

Cho, P; Woo, G C

2001-01-01

Distance and near visual acuity of 13 low astigmats were determined in a double-masked experiment through thick and thin (centre thickness 0.12 mm and 0.06 mm, respectively) spherical lathe-cut soft lenses. For each lens type, distance and near LogMAR VA and over-refraction were assessed with different logMAR VA charts. For 70% of the subjects, the residual astigmatism was significantly lower than the refractive astigmatism with thicker lenses. No statistically significant differences in the distance and near logMAR VA was found between the two lens types using any of the charts used, though, in general, logMAR VA obtained through the thicker lens was better than logMAR VA through the thinner lens. The variabilities in distance and near logMAR VA between the two lens types increased with decreased contrast. The variabilities in distance logMAR VA were greater with Chinese charts than with English charts, and LogMAR VA with Chinese charts were significantly worse for both lens types. Based on the results of this study, we concluded that thicker spherical lathe-cut soft lenses provide better vision in low astigmats. The Snellen acuity test is inadequate for vision assessment of soft contact lens wearers. When a patient wearing thin soft contact lenses complains of poor vision in spite of 6/6 or 6/5 Snellen acuity, changing to thicker lenses may be considered.

Differences in children and adolescents' ability of reporting two CVS-related visual problems.

PubMed

Hu, Liang; Yan, Zheng; Ye, Tiantian; Lu, Fan; Xu, Peng; Chen, Hao

2013-01-01

The present study examined whether children and adolescents can correctly report dry eyes and blurred distance vision, two visual problems associated with computer vision syndrome. Participants are 913 children and adolescents aged 6-17. They were asked to report their visual problems, including dry eyes and blurred distance vision, and received an eye examination, including tear film break-up time (TFBUT) and visual acuity (VA). Inconsistency was found between participants' reports of dry eyes and TFBUT results among all 913 participants as well as for all of four subgroups. In contrast, consistency was found between participants' reports of blurred distance vision and VA results among 873 participants who had never worn glasses as well as for the four subgroups. It was concluded that children and adolescents are unable to report dry eyes correctly; however, they are able to report blurred distance vision correctly. Three practical implications of the findings were discussed. Little is known about children's ability to report their visual problems, an issue critical to diagnosis and treatment of children's computer vision syndrome. This study compared children's self-reports and clinic examination results and found children can correctly report blurred distance vision but not dry eyes.

The risk of newly developed visual impairment in treated normal-tension glaucoma: 10-year follow-up.

PubMed

Choi, Yun Jeong; Kim, Martha; Park, Ki Ho; Kim, Dong Myung; Kim, Seok Hwan

2014-12-01

To investigate the risk and risk factors for newly developed visual impairment in treated patients with normal-tension glaucoma (NTG) followed up on for 10 years. Patients with NTG, who did not have visual impairment at the initial diagnosis and had undergone intraocular pressure (IOP)-lowering treatment for more than 7 years, were included on the basis of a retrospective chart review. Visual impairment was defined as either low vision (0.05 [20/400] ≤ visual acuity (VA) <0.3 [20/60] and/or 10 degrees ≤ central visual field (VF) <20 degrees) or blindness (VA <0.05 [20/400] and/or central VF <10 degrees) by World Health Organization (WHO) criteria. To investigate the risk and risk factors for newly developed visual impairment, Kaplan-Meier survival analysis and generalized linear mixed effects models were utilized. During the 10.8 years mean follow-up period, 20 eyes of 16 patients were diagnosed as visual impairment (12 eyes as low vision, 8 as blindness) among 623 eyes of 411 patients. The cumulative risk of visual impairment in at least one eye was 2.8% at 10 years and 8.7% at 15 years. The risk factors for visual impairment from treated NTG were worse VF mean deviation (MD) at diagnosis and longer follow-up period. The risk of newly developed visual impairment in the treated patients with NTG was relatively low. Worse VF MD at diagnosis and longer follow-up period were associated with development of visual impairment. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Does Assessing Eye Alignment along with Refractive Error or Visual Acuity Increase Sensitivity for Detection of Strabismus in Preschool Vision Screening?

PubMed Central

2007-01-01

Purpose Preschool vision screenings often include refractive error or visual acuity (VA) testing to detect amblyopia, as well as alignment testing to detect strabismus. The purpose of this study was to determine the effect of combining screening for eye alignment with screening for refractive error or reduced VA on sensitivity for detection of strabismus, with specificity set at 90% and 94%. Methods Over 3 years, 4040 preschool children were screened in the Vision in Preschoolers (VIP) Study, with different screening tests administered each year. Examinations were performed to identify children with strabismus. The best screening tests for detecting children with any targeted condition were noncycloplegic retinoscopy (NCR), Retinomax autorefractor (Right Manufacturing, Virginia Beach, VA), SureSight Vision Screener (Welch-Allyn, Inc., Skaneateles, NY), and Lea Symbols (Precision Vision, LaSalle, IL and Good-Lite Co., Elgin, IL) and HOTV optotypes VA tests. Analyses were conducted with these tests of refractive error or VA paired with the best tests for detecting strabismus (unilateral cover testing, Random Dot “E” [RDE] and Stereo Smile Test II [Stereo Optical, Inc., Chicago, IL]; and MTI PhotoScreener [PhotoScreener, Inc., Palm Beach, FL]). The change in sensitivity that resulted from combining a test of eye alignment with a test of refractive error or VA was determined with specificity set at 90% and 94%. Results Among the 4040 children, 157 were identified as having strabismus. For screening tests conducted by eye care professionals, the addition of a unilateral cover test to a test of refraction generally resulted in a statistically significant increase (range, 15%–25%) in detection of strabismus. For screening tests administered by trained lay screeners, the addition of Stereo Smile II to SureSight resulted in a statistically significant increase (21%) in sensitivity for detection of strabismus. Conclusions The most efficient and low-cost ways to achieve a statistically significant increase in sensitivity for detection of strabismus were by combining the unilateral cover test with the autorefractor (Retinomax) administered by eye care professionals and by combining Stereo Smile II with SureSight administered by trained lay screeners. The decision of whether to include a test of alignment should be based on the screening program’s goals (e.g., targeted visual conditions) and resources. PMID:17591881

Corticotherapy vs. Corticotherapy Plus Immunosuppressive Therapy in Acute Vogt-Koyanagi-Harada Disease.

PubMed

Concha-Del Río, L E; Gómez, L; Arellanes-García, L

2018-05-01

Vogt-Koyanagi-Harada disease is a multisystem disorder characterized by a bilateral granulomatous panuveitis. Multiple therapeutic regimens have been used to control inflammation in acute uveitic stage to prevent irreversible visual loss. The purpose of this paper is to compare the effect, on functional and anatomic outcomes, of early treatment with standard corticotherapy vs. corticotherapy plus immunosuppressive (IMT) therapy in acute Vogt-Koyanagi-Harada disease (Group A vs Group B). A retrospective chart review of patients with Vogt-Koyanagi-Harada disease, with an evolution time of 2 weeks or less, who attended the Inflammatory Eye Disease Clinic, from 2001 to 2015. Data collected included demographic information, presenting features, treatment and improvement in visual acuity (VA). Sixteen charts were reviewed; 15 females (93.75%). Mean age: 30.81±10.53 years, follow-up time (months): 54.94±43.43. Ten patients (66.6%) had IMT, azathioprine, methotrexate and cyclophosphamide. In group A, initial VA<20/200 in 66.7%; final VA was ≥20/40 in 9 eyes (75%). In group B, initial VA<20/200 in 65%; final VA≥20/40 in 15 eyes (75%). In group A, VA improved faster at one and 3 months (ANOVA P<.057). Clinical characteristics in convalescent stage and complications were similar. Anterior chamber recurrences occurred in both groups and posterior pole recurrences were observed in group A. Time to first recurrence was similar (P<.279). Frequency of recurrence was 2.33±1.80 vs 1.5±0.79 (P<.01). At recurrence 15 patients were still having oral steroids, nine in group A, 6 in Group B. In group A, prednisone was given during more time: mean 15.17±12.08 months, and time to reach to 10mg dose was longer: 8.60±11.7 (P<.008 and P<.046). Adding IMT as first line therapy to corticosteroids, do not matter significantly in terms of final VA or development of visually significant complications. In the IMT plus corticosteroids group number of recurrences was significantly lower, and a steroid sparing effect was evident. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Outcomes and Predictive Factors After Cataract Surgery in Patients With Neovascular Age-related Macular Degeneration. The Fight Retinal Blindness! Project.

PubMed

Daien, Vincent; Nguyen, Vuong; Morlet, Nigel; Arnold, Jennifer J; Essex, Rohan W; Young, Stephanie; Hunyor, Alex; Gillies, Mark C; Barthelmes, Daniel

2018-06-01

To evaluate outcomes and predictive factors of visual acuity (VA) change after cataract surgery in patients being treated for neovascular age-related macular degeneration (nAMD). Retrospective, matched case-control study. We studied eyes undergoing cataract surgery that had been tracked since they first started treatment for nAMD. These eyes were compared with a cohort of unoperated phakic eyes being treated for nAMD (3 per case) matched for treatment duration before cataract surgery, baseline VA, age, and length of follow-up. We included 124 patients that had cataract surgery and 372 matched controls. The mean (95% confidence interval) VA gained was 10.6 letters (7.8, 13.2; P < .001) 12 months after surgery; 26.0% had gained ≥3 lines and 1.6% had lost ≥3 lines of VA. Visual acuity (mean [standard deviation]) 12 months after surgery was higher in eyes that had cataract extraction compared with controls (65.8 [17.1] vs 61.3 [20.8] letters, respectively, P = .018). The proportion of visits where the choroidal neovascular (CNV) lesion was graded active and the mean number of injections were similar before and after surgery (P = .506 and P = .316, respectively), whereas both decreased in the control group, suggesting that surgery modestly increased the level of activity of the CNV lesion. Mean [SD] VA prior to surgery was lower in eyes that gained ≥15 letters compared with eyes that gained 0-14 letters (40.2 [21.4] vs 62.1 [15.1], P < .001). Patients undergoing cataract surgery within the first 6 months of anti-VEGF therapy were more likely to lose rather than gain vision (20.8% lost vision vs 12.8% and 4.4% gaining ≥15 or 0-14 letters respectively, P = .023). Age, receiving an injection at least 2 weeks before surgery, and the CNV lesion type had no discernible association with VA outcomes. We found evidence of a modest effect of cataract surgery on CNV lesion activity in eyes being treated for nAMD. Despite this, visual outcomes were reassuringly good. Cataract surgery within 6 months of starting treatment for nAMD should be avoided if possible. Copyright © 2018 Elsevier Inc. All rights reserved.

Angiographic Cystoid Macular Edema and Outcomes in the Comparison of Age-Related Macular Degeneration Treatments Trials.

PubMed

Shah, Neepa; Maguire, Maureen G; Martin, Daniel F; Shaffer, James; Ying, Gui-Shuang; Grunwald, Juan E; Toth, Cynthia A; Jaffe, Glenn J; Daniel, Ebenezer

2016-04-01

To describe morphologic and visual outcomes in eyes with angiographic cystoid macular edema (CME) treated with ranibizumab or bevacizumab for neovascular age-related macular degeneration (nAMD). Prospective cohort study within a randomized clinical trial. A total of 1185 CATT study subjects. Baseline fluorescein angiography (FA) images of all CATT study eyes were evaluated for CME. Grading of other characteristics on optical coherence tomography (OCT) and photographic images at baseline and during 2-year follow-up was completed by readers at the CATT Reading Centers. Three groups were created on the basis of baseline CME and intraretinal fluid (IRF) status: (1) CME, (2) IRF without CME, (3) neither CME nor IRF. Visual acuity (VA) and total central retinal thickness (CRT) on OCT at baseline, year 1, and year 2. Among 1131 participants with images of sufficient quality for determining CME and IRF at baseline, 92 (8.1%) had CME, 766 (67.7%) had IRF without CME, and 273 (24.1%) had neither. At baseline, eyes with CME had worse mean VA (letters) than eyes with IRF without CME and eyes with neither CME nor IRF (52 vs. 60 vs. 66 letters, P < 0.001); higher mean total CRT (μm) on OCT (514 vs. 472 vs. 404, P < 0.001); and greater hemorrhage, retinal angiomatous proliferation (RAP) lesions, and classic choroidal neovascularization (CNV). All groups showed improvement in VA at follow-up; however, the CME group started and ended with the worst VA among the 3 groups. Central retinal thickness, although higher at baseline for the CME group, was similar at 1 and 2 years follow-up for all groups. More eyes with CME (65.3%) developed scarring during 2 years of follow-up compared with eyes with IRF without CME (43.8%) and eyes with neither CME nor IRF (32.5%; P < 0.001). In CATT, eyes with CME had worse baseline and follow-up VA, although all groups showed similar rates of improvement in VA during 2 years of follow-up. Cystoid macular edema seems to be a marker for poorer visual outcomes in nAMD because of underlying baseline retinal dysfunction and subsequent scarring. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The attentive brain: insights from developmental cognitive neuroscience.

PubMed

Amso, Dima; Scerif, Gaia

2015-10-01

Visual attention functions as a filter to select environmental information for learning and memory, making it the first step in the eventual cascade of thought and action systems. Here, we review studies of typical and atypical visual attention development and explain how they offer insights into the mechanisms of adult visual attention. We detail interactions between visual processing and visual attention, as well as the contribution of visual attention to memory. Finally, we discuss genetic mechanisms underlying attention disorders and how attention may be modified by training.

Visualization and Phospholipid Identification (VaLID): online integrated search engine capable of identifying and visualizing glycerophospholipids with given mass

PubMed Central

Figeys, Daniel; Fai, Stephen; Bennett, Steffany A. L.

2013-01-01

Motivation: Establishing phospholipid identities in large lipidomic datasets is a labour-intensive process. Where genomics and proteomics capitalize on sequence-based signatures, glycerophospholipids lack easily definable molecular fingerprints. Carbon chain length, degree of unsaturation, linkage, and polar head group identity must be calculated from mass to charge (m/z) ratios under defined mass spectrometry (MS) conditions. Given increasing MS sensitivity, many m/z values are not represented in existing prediction engines. To address this need, Visualization and Phospholipid Identification is a web-based application that returns all theoretically possible phospholipids for any m/z value and MS condition. Visualization algorithms produce multiple chemical structure files for each species. Curated lipids detected by the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics are provided as high-resolution structures. Availability: VaLID is available through the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics resources web site at https://www.med.uottawa.ca/lipidomics/resources.html. Contacts: lipawrd@uottawa.ca Supplementary Information: Supplementary data are available at Bioinformatics online. PMID:23162086

The Role of Visual Processing Speed in Reading Speed Development

PubMed Central

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children. PMID:23593117

The role of visual processing speed in reading speed development.

PubMed

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

Long-term follow-up for efficacy and safety of treatment of retinitis pigmentosa with valproic acid.

PubMed

Bhalla, Sheena; Joshi, Deval; Bhullar, Shaminder; Kasuga, Daniel; Park, Yeonhee; Kay, Christine N

2013-07-01

The purpose of this study was to determine the long-term efficacy and safety of valproic acid (VPA) treatment in patients with pigmentary retinal dystrophies. A retrospective chart review was conducted on 31 patients with a diagnosis of pigmentary retinal dystrophy prescribed VPA at a single centre. Visual field (VF), visual acuity (VA), length of treatment, liver enzymes and side effects were analysed. VF areas were defined using Goldmann VF (GVF) tracings recorded before, during and after VPA treatment using the V4e isopter for each eye. Using custom software, planimetric areas of VF were calculated. Five of the patients (10 eyes) had two Goldmann VF tracings, allowing comparison between baseline and follow-up VF. After 9.8 months of VPA, VF decreased by 0.145 cm(2) (26.478%) (p=0.432). For 22 of the patients (41 eyes), VA data was available, and logarithm of the minimum angle of resolution (logMAR) score changed by 0.056 log units (representing a decline in VA) after 14.9 months on VPA (p=0.002). Twelve patients (38.7%) reported negative side effects related to VPA use. VPA plays a complex role in patients with pigmentary retinal dystrophies and may be associated with VA and field decline as well as adverse side effects. Physicians should use caution with using VPA for pigmentary retinal dystrophies.

Fixation Preference and Visual Acuity Testing in a Population-based Cohort of Preschool Children with Amblyopia Risk Factors

PubMed Central

Cotter, Susan A.; Tarczy-Hornoch, Kristina; Song, Erin; Lin, Jesse; Borchert, Mark; Azen, Stanley P.; Varma, Rohit

2009-01-01

Purpose To compare the clinical assessment of fixation preference (FP) to visual acuity (VA) in a population-based sample of preschool children with amblyopia risk factors. Design Evaluation of diagnostic test in a population-based study. Participants Two hundred forty-three children with amblyopia and/or strabismus, aged 30–72 months, living in Los Angeles County, California. Methods Before measuring VA, FP testing was performed at near and usually without correction, using the binocular fixation pattern in children with strabismus >10 diopters (D), or the induced tropia test for children with strabismus ≤10D, or without strabismus. We determined the sensitivity and specificity of FP testing for predicting unilateral amblyopia, defined by optotype VA, among children with amblyopia risk factors. Main Outcome Measure Grade of FP. Results Sensitivity of FP testing for amblyopia among children with anisometropia was 20% (9/44) and specificity was 94% (102/109). Among strabismic children, sensitivity was 69% (9/13; worse in children 30–47 than 48–72 months old) and specificity was 79% (70/89), with similar findings for esotropia and exotropia. Conclusion The ability of FP testing to correctly identify amblyopia in preschool children with amblyopia risk factors is poor. Clinicians should be wary of using FP as a surrogate measure of intraocular difference in VA in young children. PMID:18962921

Visual processing affects the neural basis of auditory discrimination.

PubMed

Kislyuk, Daniel S; Möttönen, Riikka; Sams, Mikko

2008-12-01

The interaction between auditory and visual speech streams is a seamless and surprisingly effective process. An intriguing example is the "McGurk effect": The acoustic syllable /ba/ presented simultaneously with a mouth articulating /ga/ is typically heard as /da/ [McGurk, H., & MacDonald, J. Hearing lips and seeing voices. Nature, 264, 746-748, 1976]. Previous studies have demonstrated the interaction of auditory and visual streams at the auditory cortex level, but the importance of these interactions for the qualitative perception change remained unclear because the change could result from interactions at higher processing levels as well. In our electroencephalogram experiment, we combined the McGurk effect with mismatch negativity (MMN), a response that is elicited in the auditory cortex at a latency of 100-250 msec by any above-threshold change in a sequence of repetitive sounds. An "odd-ball" sequence of acoustic stimuli consisting of frequent /va/ syllables (standards) and infrequent /ba/ syllables (deviants) was presented to 11 participants. Deviant stimuli in the unisensory acoustic stimulus sequence elicited a typical MMN, reflecting discrimination of acoustic features in the auditory cortex. When the acoustic stimuli were dubbed onto a video of a mouth constantly articulating /va/, the deviant acoustic /ba/ was heard as /va/ due to the McGurk effect and was indistinguishable from the standards. Importantly, such deviants did not elicit MMN, indicating that the auditory cortex failed to discriminate between the acoustic stimuli. Our findings show that visual stream can qualitatively change the auditory percept at the auditory cortex level, profoundly influencing the auditory cortex mechanisms underlying early sound discrimination.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PubMed

Lee, Richard M H; Ong, Gek L; Lam, Fook Chang; White, Joy; Crook, David; Liu, Christopher S C; Hull, Chris C

2014-10-01

The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

Fine Motor Skills of Children With Amblyopia Improve Following Binocular Treatment.

PubMed

Webber, Ann L; Wood, Joanne M; Thompson, Benjamin

2016-09-01

The purpose of this study was to determine whether reduced fine motor skills in children with amblyopia improve after binocular treatment and whether improvements are sustained once treatment has ceased. Fine motor skills (FMS [Bruininks-Oseretsky Test of Motor Proficiency]), visual acuity (VA [Early Treatment of Diabetic Retinopathy Study chart]) and level of binocular function (BF [Randot preschool stereoacuity and Worth 4 Dot]) were measured in children with amblyopia (n = 20; age: 8.5 ± 1.3 years; 11 anisometropic; 5 strabismic; 4 mixed) and in a group of visually normal children (n = 10; age: 9.63 ± 1.6 years). Eighteen children with amblyopia subsequently completed 5 weeks of binocular treatment provided by home-based dichoptic iPod game play. FMS, VA, and BF were retested at the end of treatment and 12 weeks after treatment cessation. All visually normal children also completed FMS measurements at baseline and 5 weeks later to assess test-retest variability of the FMS scores. Prior to treatment, FMS scores in children with amblyopia were poorer than those in children with normal vision (P < 0.05). In the children with amblyopia, binocular treatment significantly improved FMS scores (P < 0.05). Better baseline amblyopic eye VA and BF were associated with greater improvements in FMS score. Improvements were still evident at 12 weeks post treatment. In the visually normal children, FMS scores remained stable across the two test sessions. Binocular treatment provided by dichoptic iPod game play improved FMS performance in children with amblyopia, particularly in those with less severe amblyopia. Improvements were maintained at 3 months following cessation of treatment.

Management Modalities for Traumatic Macular Hole: A Systematic Review and Single-Arm Meta-Analysis.

PubMed

Gao, Min; Liu, Kun; Lin, Qiurong; Liu, Haiyun

2017-02-01

The purposes of this study were to (i) determine macular hole (MH) closure rates and visual outcomes by comparing two methods of managing traumatic MH (TMH)-an event resulting in severe loss of visual acuity (VA); (ii) characterize patients who undergo spontaneous TMH closure; (iii) determine which TMH patients should be observed before resorting to surgical repair; and (iv) elucidate factors that influence postoperative visual outcomes. Studies (n=10) of patients who were managed by surgery or observation for TMH were meta-analyzed retrospectively. Management modalities included surgical repair (surgery group) and observation for spontaneous hole closure (observation group). In addition, a 12-case series of articles (1990-2014) on spontaneous hole closure was statistically summarized. SAS and Comprehensive Meta-Analysis (CMA) (version 3.0) were used for analysis. For surgery group patients, the fixed-model pooled event rate for hole closure was 0.919 (range, 0.861-0.954) and for observation group patients, 0.368 (range, 0.236-0.448). The random-model pooled event rate for improvement of visual acuity (VA) for surgery group patients was 0.748 (range, 0.610-0.849) and for observation group patients, 0.505 (range, 0.397-0.613). For patients in both groups, the mean age of spontaneous closure was 18.71±10.64 years; mean size of TMHs, 0.18±0.06 decimal degrees (DD); and mean time for hole closure, 3.38±3.08 months. The pooled event rate for visual improvement was 0.748 (0.610-0.849). Hole closure and VA improvement rates of surgery group patients were significantly higher than those for observation group patients. Patients of ≤ 24 years of age with MH sizes of ≤ 0.2DD were more likely to achieve spontaneous hole closure. The interval of time from injury to surgery was statistically significantly associated with the level of visual improvement.

Business intelligence from social media: a study from the VAST Box Office Challenge.

PubMed

Lu, Yafeng; Wang, Feng; Maciejewski, Ross

2014-01-01

With over 16 million tweets per hour, 600 new blog posts per minute, and 400 million active users on Facebook, businesses have begun searching for ways to turn real-time consumer-based posts into actionable intelligence. The goal is to extract information from this noisy, unstructured data and use it for trend analysis and prediction. Current practices support the idea that visual analytics (VA) can help enable the effective analysis of such data. However, empirical evidence demonstrating the effectiveness of a VA solution is still lacking. A proposed VA toolkit extracts data from Bitly and Twitter to predict movie revenue and ratings. Results from the 2013 VAST Box Office Challenge demonstrate the benefit of an interactive environment for predictive analysis, compared to a purely statistical modeling approach. The VA approach used by the toolkit is generalizable to other domains involving social media data, such as sales forecasting and advertisement analysis.

Full ocular biometry through dual-depth whole-eye optical coherence tomography

PubMed Central

Kim, Hyung-Jin; Kim, Minji; Hyeon, Min Gyu; Choi, Youngwoon; Kim, Beop-Min

2018-01-01

We propose a new method of determining the optical axis (OA), pupillary axis (PA), and visual axis (VA) of the human eye by using dual-depth whole-eye optical coherence tomography (OCT). These axes, as well as the angles “α” between the OA and VA and “κ” between PA and VA, are important in many ophthalmologic applications, especially in refractive surgery. Whole-eye images are reconstructed based on simultaneously acquired images of the anterior segment and retina. The light from a light source is split into two orthogonal polarization components for imaging the anterior segment and retina, respectively. The OA and PA are identified based on their geometric definitions by using the anterior segment image only, while the VA is detected through accurate correlation between the two images. The feasibility of our approach was tested using a model eye and human subjects. PMID:29552378

Short-term effects of instillation of a rebamipide suspension on visual function.

PubMed

Kaido, Minako; Ishida, Reiko; Dogru, Murat; Tsubota, Kazuo

2014-05-01

To investigate the short-term adverse effects of using rebamipide for the treatment of dry eye by assessing visual function and optical quality. This interventional noncomparative study included 14 right eyes of 14 healthy volunteers. Serial measurements of visual acuity (VA) and higher-order aberrations were obtained prior to instillation of the rebamipide suspension (baseline) and immediately after and at 5, 10, 20, and 30 min after instillation. Functional VA measurement was performed over a 60-s period with the subject blinking naturally. Ocular aberrations were measured for 10 s while the subject was told not to blink, but no topical anesthesia was applied. Each patient also filled out a questionnaire exploring the rebamipide-associated adverse effects. There was no significant difference between functional VA measured at baseline and at each time point after the instillation of rebamipide. In contrast, the root mean square of third-order and total higher-order aberrations increased significantly immediately after drug instillation (P<0.05). The severity of higher-order aberrations at baseline was similar to that observed at 5, 10, 20, and 30 min after instillation (P>0.05). The transient reduction in optical quality immediately after administration of rebamipide is corrected by the patient's natural blink reflex. The adverse effects observed in this study do not outweigh the benefits of rebamipide treatment.

Five-Year Outcomes of Surgically Treated Symptomatic Epiretinal Membranes With and Without Internal Limiting Membrane Peeling.

PubMed

Sultan, Harris; Wykoff, Charles C; Shah, Ankoor R

2018-05-01

The authors evaluated long-term postoperative visual outcomes and recurrence rates following surgery for symptomatic epiretinal membrane (ERM) ± internal limiting membrane (ILM) peeling. This was a retrospective, consecutive case series of 78 patients undergoing vitrectomy for symptomatic ERM between 1/2010 and 4/2012 with follow-up through at least postoperative year 5 (POY5). Outcomes included visual acuity (VA) (Snellen VA converted to logMAR), central retinal thickness (CRT; μm), and ERM recurrence. Subgroup analysis evaluated outcomes related to ILM peeling. Subgroup analysis based on ILM peeling did not find VA (20/50 [0.430 logMAR ± 0.061 logMAR; mean ± SD] vs. 20/60 [0.518 logMAR ± 0.128 logMAR] for ILM vs. non-ILM peeling respectively; P = .513) nor macular thickness (355 μm ± 13 μm vs. 360 μm ± 42 μm; P = .410) to be significantly different at POY5. Recurrence requiring surgery with and without ILM peeling was not statistically significantly different at POY5 (1.6% and 11.8%; P = .118). Vitrectomy for symptomatic ERM led to improved visual and anatomic outcomes with sustained benefit through 5 years. ILM peeling was was associated with reduced ERM recurrence, but this benefit was not statistically significant at POY5. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:296-302.]. Copyright 2018, SLACK Incorporated.

The challenge of big data in public health: an opportunity for visual analytics.

PubMed

Ola, Oluwakemi; Sedig, Kamran

2014-01-01

Public health (PH) data can generally be characterized as big data. The efficient and effective use of this data determines the extent to which PH stakeholders can sufficiently address societal health concerns as they engage in a variety of work activities. As stakeholders interact with data, they engage in various cognitive activities such as analytical reasoning, decision-making, interpreting, and problem solving. Performing these activities with big data is a challenge for the unaided mind as stakeholders encounter obstacles relating to the data's volume, variety, velocity, and veracity. Such being the case, computer-based information tools are needed to support PH stakeholders. Unfortunately, while existing computational tools are beneficial in addressing certain work activities, they fall short in supporting cognitive activities that involve working with large, heterogeneous, and complex bodies of data. This paper presents visual analytics (VA) tools, a nascent category of computational tools that integrate data analytics with interactive visualizations, to facilitate the performance of cognitive activities involving big data. Historically, PH has lagged behind other sectors in embracing new computational technology. In this paper, we discuss the role that VA tools can play in addressing the challenges presented by big data. In doing so, we demonstrate the potential benefit of incorporating VA tools into PH practice, in addition to highlighting the need for further systematic and focused research.

The Challenge of Big Data in Public Health: An Opportunity for Visual Analytics

PubMed Central

Ola, Oluwakemi; Sedig, Kamran

2014-01-01

Public health (PH) data can generally be characterized as big data. The efficient and effective use of this data determines the extent to which PH stakeholders can sufficiently address societal health concerns as they engage in a variety of work activities. As stakeholders interact with data, they engage in various cognitive activities such as analytical reasoning, decision-making, interpreting, and problem solving. Performing these activities with big data is a challenge for the unaided mind as stakeholders encounter obstacles relating to the data’s volume, variety, velocity, and veracity. Such being the case, computer-based information tools are needed to support PH stakeholders. Unfortunately, while existing computational tools are beneficial in addressing certain work activities, they fall short in supporting cognitive activities that involve working with large, heterogeneous, and complex bodies of data. This paper presents visual analytics (VA) tools, a nascent category of computational tools that integrate data analytics with interactive visualizations, to facilitate the performance of cognitive activities involving big data. Historically, PH has lagged behind other sectors in embracing new computational technology. In this paper, we discuss the role that VA tools can play in addressing the challenges presented by big data. In doing so, we demonstrate the potential benefit of incorporating VA tools into PH practice, in addition to highlighting the need for further systematic and focused research. PMID:24678376

VA's National PTSD Brain Bank: a National Resource for Research.

PubMed

Friedman, Matthew J; Huber, Bertrand R; Brady, Christopher B; Ursano, Robert J; Benedek, David M; Kowall, Neil W; McKee, Ann C

2017-08-25

The National PTSD Brain Bank (NPBB) is a brain tissue biorepository established to support research on the causes, progression, and treatment of PTSD. It is a six-part consortium led by VA's National Center for PTSD with participating sites at VA medical centers in Boston, MA; Durham, NC; Miami, FL; West Haven, CT; and White River Junction, VT along with the Uniformed Services University of Health Sciences. It is also well integrated with VA's Boston-based brain banks that focus on Alzheimer's disease, ALS, chronic traumatic encephalopathy, and other neurological disorders. This article describes the organization and operations of NPBB with specific attention to: tissue acquisition, tissue processing, diagnostic assessment, maintenance of a confidential data biorepository, adherence to ethical standards, governance, accomplishments to date, and future challenges. Established in 2014, NPBB has already acquired and distributed brain tissue to support research on how PTSD affects brain structure and function.

Contributions of Optical and Non-Optical Blur to Variation in Visual Acuity

PubMed Central

McAnany, J. Jason; Shahidi, Mahnaz; Applegate, Raymond A.; Zelkha, Ruth; Alexander, Kenneth R.

2011-01-01

Purpose To determine the relative contributions of optical and non-optical sources of intrinsic blur to variations in visual acuity (VA) among normally sighted subjects. Methods Best-corrected VA of sixteen normally sighted subjects was measured using briefly presented (59 ms) tumbling E optotypes that were either unblurred or blurred through convolution with Gaussian functions of different widths. A standard model of intrinsic blur was used to estimate each subject’s equivalent intrinsic blur (σint) and VA for the unblurred tumbling E (MAR0). For 14 subjects, a radially averaged optical point spread function due to higher-order aberrations was derived by Shack-Hartmann aberrometry and fit with a Gaussian function. The standard deviation of the best-fit Gaussian function defined optical blur (σopt). An index of non-optical blur (η) was defined as: 1-σopt/σint. A control experiment was conducted on 5 subjects to evaluate the effect of stimulus duration on MAR0 and σint. Results Log MAR0 for the briefly presented E was correlated significantly with log σint (r = 0.95, p < 0.01), consistent with previous work. However, log MAR0 was not correlated significantly with log σopt (r = 0.46, p = 0.11). For subjects with log MAR0 equivalent to approximately 20/20 or better, log MAR0 was independent of log η, whereas for subjects with larger log MAR0 values, log MAR0 was proportional to log η. The control experiment showed a statistically significant effect of stimulus duration on log MAR0 (p < 0.01) but a non-significant effect on σint (p = 0.13). Conclusions The relative contributions of optical and non-optical blur to VA varied among the subjects, and were related to the subject’s VA. Evaluating optical and non-optical blur may be useful for predicting changes in VA following procedures that improve the optics of the eye in patients with both optical and non-optical sources of VA loss. PMID:21460756

Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive

PubMed Central

Spreng, Lucie; Favrat, Bernard; Borruat, François-Xavier; Vaucher, Paul

2018-01-01

Objectives The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. Design A predictive cross-sectional study. Setting Volunteer participants to a drivers’ refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. Participants 162 drivers, male and female, aged 70 years or older. Clinical predictors We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. Outcomes We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Results Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R2=0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R2=0.004, P=0.454; CS: R2=0.006, P=0.332). Conclusion CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study. PMID:29374663

The Association of Race with Childhood Uveitis

PubMed Central

Angeles-Han, Sheila T; McCracken, Courtney; Yeh, Steven; Jenkins, Kirsten; Stryker, Daneka; Travers, Curtis; Rouster-Stevens, Kelly; Vogler, Larry B.; Lambert, Scott R.; Drews-Botsch, Carolyn; Prahalad, Sampath

2015-01-01

Purpose To identify risk factors for a severe uveitis course among children with non-infectious uveitis. Design Retrospective cohort study Method This was a retrospective analysis of a prospectively collected database. Records of 94 children with uveitis were reviewed at enrollment and every 3-6 months (2011-2015). Severe uveitis was defined as a history of ocular complications or a visual acuity (VA) of ≤20/200. Children were compared by disease, VA, complications and race. Regression models were used to model risk factors for severe disease. When examining race, we focused on non-Hispanic African American and non-Hispanic White children only. Results Of 85 children with uveitis and complete ocular examinations, 27 (32%) had a history of a VA of ≤20/200. A subanalysis of non-Hispanic African American and White children showed an increased prevalence of VA ≤20/200 in non-Hispanic African Americans (18/25 (72%) vs. 4/43 (9%)). Non-Hispanic African Americans were more likely to be diagnosed at an older age (p=0.030), have intermediate uveitis (p=0.026), bilateral disease (p=0.032), a history of VA ≤20/50 (p=0.002), VA ≤20/200 (p<0.001), and a higher rate of complications (p<0.001). On multivariable analysis, non-Hispanic African American race was a significant predictor of blindness (OR=31.6, 95% CI (5.9– 168.5), p<0.001), after controlling for uveitis duration. Non-Hispanic African Americans also developed 2.2 times more unique complications per year of disease than non-Hispanic Whites when controlling for uveitis type and duration. Conclusions There appear to be racial differences in the outcomes of children with uveitis. Non-Hispanic African American children with non-juvenile idiopathic arthritis associated uveitis may have worse visual outcomes with increased vision loss and ocular complications. These findings highlight the need for future studies in minority populations. PMID:26255577

Accuracy of Voice-Announcement Pedometers for Youth with Visual Impairment

ERIC Educational Resources Information Center

Beets, Michael W.; Foley, John T.; Tindall, Daniel W. S.; Lieberman, Lauren J.

2007-01-01

Thirty-five youth with visual impairments (13.5 plus or minus 2.1 yrs, 13 girls and 22 boys) walked four 100-meter distances while wearing two units (right and left placement) of three brands of voice-announcement (VA) pedometers (Centrios[TM] Talking Pedometer, TALKiNG Pedometer, and Sportline Talking Calorie Pedometer 343) and a reference…

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2010-08-02

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The Role of Vision in Academic School Performance

PubMed Central

Dirani, Mohamed; Zhang, Xiaoe; Goh, Liang Ke; Young, Terri L.; Lee, Paul; Saw, Seang Mei

2014-01-01

Purpose To determine whether presenting distance visual acuity is related to subsequent academic school performance in Singaporean children between 9 to 10 years of age. Methods Singapore children (n = 1143 children) were examined during their visits at ages 9 to 10 years (grades 3 to 4) as part of the Singapore Cohort Study of the Risk Factors for Myopia (SCORM) longitudinal study. Each child underwent an annual comprehensive eye examination, including the assessment of presenting logarithm of the minimum angle of resolution (LogMAR) distance visual acuity (VA). The individual marks of a nation-wide standard examination in grade 4 were used as the outcome measure for academic school performance. Children with any known eye disease, (such as media opacities) were excluded from the analysis. Results The mean presenting distance VA of the better eye was 0.10 and 0.08 when the children were in grades 3 and 4, respectively. There was a statistically significant difference for mean presenting VA with 9 and 10 year old boys scoring better (0.08 and 0.07) compared to girls (0.12 and 0.09) for the same ages, (p = 0.001 and p = 0.007), respectively. After adjusting for gender, ethnicity, school, reading, intelligence quotient and father’s education, no significant relationships were found between average examination marks at the end of grade 4 and presenting VA obtained (better eye and worst eye) in grade 3 (p = 0.38 and p = 0.98) and 4 (p = 0.27 and p = 0.16). Conclusion In our sample of Singaporean children without ocular disease, distance VA did not play a significant role in predicting academic school performance. PMID:20100096

Prevalence and incidence of blindness and other degrees of sight impairment in patients treated for neovascular age-related macular degeneration in a well-defined region of the United Kingdom.

PubMed

Buckle, M; Lee, A; Mohamed, Q; Fletcher, E; Sallam, A; Healy, R; Stratton, I; Tufail, A; Johnston, R L

2015-03-01

This study aimed to evaluate the incidence and prevalence of blindness, sight impairment, and other visual acuity (VA) states in patients receiving ranibizumab for neovascular age-related macular degeneration (nAMD) in Gloucestershire. Serial VA and injection data for all treatment-naive patients receiving their first intravitreal injections of ranibizumab for nAMD in the Gloucestershire National Health Service Ophthalmology department between 2008 and 2010 were extracted from an electronic medical record system. The prevalence of blindness (VA in the better-seeing eye ≤25 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) at the time of first intravitreal injection was 0.8%, increasing to 3.5% after 3 years. The prevalence of sight impairment (VA in the better-seeing eye 26-39 ETDRS letters) increased from 4.1% at baseline to 5.5% after 3 years. The incidence of initiating ranibizumab treatment for nAMD in people aged ≥50 years in Gloucestershire was 111 people per 100 000 population in 2009, and 97 people in 2010. The incidence of patients meeting the visual criteria for blindness and sight impairment registration from treated nAMD in people aged ≥50 years in Gloucestershire was 3.5 and 9.7 people, respectively per 100 000 population in 2010. This is the first real-world study on the incidence and prevalence of eligibility for blindness and sight impairment registration in treated nAMD in the UK based on VA data. The incidence and prevalence of eligibility for certification of blindness or sight impairment in patients treated with ranibizumab for nAMD is low in Gloucestershire, with only 3.6% of the incident population progressing to blindness in 2010.

Continuous full-time occlusion of the sound eye vs full-time occlusion of the sound eye periodically alternating with occlusion of the amblyopic eye in treatment of amblyopia: a prospective randomized study.

PubMed

Stanković, B; Milenković, S

2007-01-01

To compare continuous full-time (24 hours per day) occlusion of the sound eye with full-time occlusion (24 hours per day) of the sound eye 1 day more than the years of age periodically alternating with occlusion of the amblyopic eye for 1 day, as treatments for profound strabismic amblyopia in children older than 5 years. A total of 53 patients with visual acuity (VA) of 0.4 and less in the amblyopic eye (tested by crowded Landolt Cs) after previously being provided optimal optical correction were randomly assigned to receive either of the two patching regimens. VA and pattern reversal visual evoked potentials (PVEP) were recorded prospectively at 1-month intervals. Improvement in VA and the reduction in crowding difficulties (CD) were the main outcome measures of the treatment efficiency. Both treatment modalities were equally effective. Of the 51 subjects who completed the study, 21 (41.2%) were cured whereas 32 (62.7%) attained satisfactory improvement. Recovery of VA was related to age, with cure being obtained in 23.5% (4/17) and satisfactory improvement in 52.9% (9/17) of patients older than 9 years. Larger gain in VA influenced the stability of the vision over time. It can be concluded that in clinically monitored parameters both treatment modalities were equally effective without any statistical or clinical significance in the observed groups of patients. However, events like the "trade-off" effect, occurrence of occlusion amblyopia, or prolongation of PVEP latency of the sound eye indicate that full-time continuous occlusion possibly presents a more effective form of treatment.

Intraocular methotrexate in the treatment of uveitis and uveitic cystoid macular edema.

PubMed

Taylor, Simon R J; Habot-Wilner, Zohar; Pacheco, Patricio; Lightman, Sue L

2009-04-01

A pilot study to evaluate the use of intravitreal methotrexate (MTX) for the treatment of uveitis and uveitic cystoid macular edema (CME). Prospective, consecutive, interventional case series. Fifteen eyes of 15 patients with a unilateral exacerbation of noninfectious intermediate, posterior uveitis, or panuveitis and/or CME such that visual acuity (VA) was 20/40 or worse, together with a history of increased intraocular pressure (IOP) in response to corticosteroid administration. Intravitreal injection of 400 microg in 0.1 ml MTX. The primary outcome measure was VA (using the Early Treatment Diabetic Retinopathy Study chart). Other outcome measures included ocular inflammation scores, time to relapse, levels of systemic corticosteroid and immunosuppressive therapy, and ocular coherence tomography. Potential complications of intravitreal MTX injection, including cataract progression, vitreous hemorrhage, retinal detachment, and corneal epitheliopathy, were assessed. VA improved at all time points and was statistically significant at the 3- and 6-month follow-up examinations. The mean visual improvement was 4 lines at 3 months and 4.5 lines at 6 months, with no statistical difference between the best VA obtained after MTX injection and after previous corticosteroid treatment, including intravitreal triamcinolone acetate injection. Five patients relapsed after a median of 4 months; a similar improvement was seen after re-injection. Ocular inflammation scores improved at all time points, and systemic immunosuppressive medication was reduced in 3 of 7 patients taking this at the start of the trial. In patients with uveitis and uveitic CME, intravitreal MTX can improve VA and reduce CME and, in some patients, allows the reduction of immunosuppressive therapy. Relapse occurs at a median of 4 months in some patients, but reinjection has similar efficacy.

The U.S. Air Force Photorefractive Keratectomy (PRK) Study: Evaluation of Residual Refractive Error and High- and Low-Contrast Visual Acuity

DTIC Science & Technology

2006-07-01

values for statistical analyses in terms of Snellen equivalent VA (Ref 44) and lines gained vs . lost after PRK . The Snellen VA values shown in the...AFRL-SA-BR-TR-2010-0011 THE U.S. AIR FORCE PHOTOREFRACTIVE KERATECTOMY ( PRK ) STUDY: Evaluation of Residual Refractive Error and High...July 2006 4. TITLE AND SUBTITLE THE U.S. AIR FORCE PHOTOREFRACTIVE KERATECTOMY ( PRK ) STUDY: Evaluation of Residual Refractive Error and High- and

Predictors of visual outcomes in patients with neovascular age-related macular degeneration treated with anti-vascular endothelial growth factor therapy: post hoc analysis of the VIEW studies.

PubMed

Lanzetta, Paolo; Cruess, Alan F; Cohen, Salomon Y; Slakter, Jason S; Katz, Todd; Sowade, Olaf; Zeitz, Oliver; Ahlers, Christiane; Mitchell, Paul

2018-04-16

Identify predictors for response to anti-vascular endothelial growth factor (VEGF) therapy in patients with neovascular (wet) age-related macular degeneration (nAMD). Retrospective, post hoc analysis of VIEW 1/2. Patients were randomized 1:1:1:1 to 0.5 mg intravitreal aflibercept (IVT-AFL) injection every 4 weeks (0.5q4); 2 mg IVT-AFL every 4 weeks (2q4); 2 mg IVT-AFL every 8 weeks (2q8) after an initial three injections at weeks 0, 4 and 8 or 0.5 mg intravitreal ranibizumab every 4 weeks (0.5q4). 1815 patients [IVT-AFL 2q4 (n = 613); IVT-AFL 2q8 (n = 607); ranibizumab 0.5q4 (n = 595)] were included. Baseline demographics/characteristics were evenly balanced. Younger age (49-69 years), lower visual acuity (VA) [10.0-≤45.0 Early Treatment Diabetic Retinopathy Study (ETDRS) letters] and smaller choroidal neovascularization (CNV) size [0.0-≤3.1 disc areas (DA)] at baseline were associated with the most vision gain (≥15 letters) over 52 weeks (all nominal p < 0.0001).Younger age, higher baseline VA (>64.0-≤83.0 letters) and smaller CNV size were associated with a VA ≥20/40 at week 52. Predominantly classic CNV at baseline (nominal p = 0.0007), older age (≥90 years), lower baseline VA (10.0-≤ 45.0 ETDRS letters) and larger CNV size (>10.1-≤32.6 DA) were all associated with a VA ≤20/200 at week 52 (all nominal p < 0.0001). Along with treatment (nominal p < 0.0001), lower VA (p = 0.0166) and smaller central retinal thickness (both nominal p = 0.0190) were predictors for dry retina development. Younger age, lower VA and smaller CNV size at baseline were all associated with greater vision gains over 52 weeks while younger age, higher VA and smaller CNV size at treatment start were more likely to achieve best-corrected VA 20/40 or better after a year's treatment, suggesting the benefit of early anti-VEGF treatment. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Macular grid laser photocoagulation for branch retinal vein occlusion.

PubMed

Lam, Fook Chang; Chia, Seen N; Lee, Richard M H

2015-05-11

Branch retinal vein occlusion (BRVO) is the second most common cause of retinal vascular abnormality after diabetic retinopathy. Persistent macular oedema develops in 60% of eyes with a BRVO. Untreated, only 14% of eyes with chronic macular oedema will have a visual acuity (VA) of 20/40 or better. Macular grid laser photocoagulation is used for chronic non-ischaemic macular oedema following BRVO and has been the mainstay of treatment for over 20 years. New treatments are available and a systematic review is necessary to ensure that the most up-to-date evidence is considered objectively. To examine the effects of macular grid laser photocoagulation in the treatment of macular oedema following BRVO. We searched CENTRAL, Ovid MEDLINE, EMBASE, Web of Science Conference Proceedings Citation Index, the metaRegister of Controlled Trials (mRCT), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 21 August 2014. We included randomised controlled trials (RCTs) comparing macular grid laser photocoagulation treatment to another treatment, sham treatment or no treatment. We used standard methodological procedures expected by Cochrane. We included five studies conducted in Europe and North America. Four separate trials compared grid laser to no treatment, sham treatment, intravitreal bevacizumab and intravitreal triamcinolone. One further trial compared subthreshold to threshold laser. Two of these trials were judged to be at high risk of bias in one or more domains.In one trial of grid laser versus observation, people receiving grid laser were more likely to gain visual acuity (VA) (10 or more ETDRS letters) at 36 months (RR 1.75, 95% confidence interval (CI) 1.08 to 2.84, 78 participants, moderate-quality evidence). The effect of grid laser on loss of VA (10 or more letters) was uncertain as the results were imprecise (RR 0.68, 95% CI 0.23 to 2.04, 78 participants, moderate-quality evidence). On average, people receiving grid laser had better improvement in VA (mean difference (MD) 0.11 logMAR, 95% CI 0.05 to 0.17, high-quality evidence). In a trial of early and delayed grid laser treatment versus sham laser (n = 108, data available for 99 participants), no participant gained or lost VA (15 or more ETDRS letters). At 12 months, there was no evidence for a difference in change in VA (from baseline) between early grid laser and sham laser (MD -0.03 logMAR, 95% confidence interval (CI) -0.07 to 0.01, 68 participants, low-quality evidence) or between delayed grid laser and sham laser (MD 0.00, 95% CI -0.04 to 0.04, 66 participants, low-quality evidence).The relative effects of subthreshold and threshold laser were uncertain. In one trial, the RR for gain of VA (15 or more letters) at 12 months was 1.68 (95% CI 0.57 to 4.95, 36 participants, moderate-quality evidence); the RR for loss of VA (15 or more letters) was 0.56 (95% CI 0.06 to 5.63, moderate-quality evidence); and at 24 months the change in VA from baseline was MD 0.07 (95% CI -0.10 to 0.24, moderate-quality evidence).The relative effects of macular grid laser and intravitreal bevacizumab were uncertain. In one trial, the RR for gain of 15 or more letters at 12 months was 0.67 (95% CI 0.39 to 1.14, 30 participants, low-quality evidence). Loss of 15 or more letters was not reported. Change in VA at 12 months was MD 0.11 logMAR (95% CI -0.36 to 0.14, low-quality evidence).The relative effects of grid laser and 1mg triamcinolone were uncertain at 12 months. RR for gain of VA (15 or more letters) was 1.13 (95% CI 0.75 to 1.71, 1 RCT, 242 participants, moderate-quality evidence); RR for loss of VA (15 or more letters) was 1.20 (95% CI 0.63 to 2.27, moderate-quality evidence); MD for change in VA was -0.03 letters (95% CI -0.12 to 0.06, moderate-quality evidence). Similar results were seen for the comparison with 4mg triamcinolone. Beyond 12 months, the visual outcomes were in favour of grid laser at 24 months and 36 months with people in the macular grid group gaining more VA.Four studies reported on adverse effects. Laser photocoagulation appeared to be well tolerated in the studies. One participant (out of 71) suffered a perforation of Bruch's membrane, but this did not affect visual acuity. Moderate-quality evidence from one RCT supports the use of grid laser photocoagulation to treat macular oedema following BRVO. There was insufficient evidence to support the use of early grid laser or subthreshold laser. There was insufficient evidence to show a benefit of intravitreal triamcinolone or anti-vascular endothelial growth factor (VEGF) over macular grid laser photocoagulation in BRVO. With recent interest in the use of intravitreal anti-VEGF or steroid therapy, assessment of treatment efficacy (change in visual acuity and foveal or central macular thickness using optical coherence tomography (OCT)) and the number of treatments needed for maintenance and long-term safety will be important for future studies.

Keeping your eyes on the prize: anger and visual attention to threats and rewards.

PubMed

Ford, Brett Q; Tamir, Maya; Brunyé, Tad T; Shirer, William R; Mahoney, Caroline R; Taylor, Holly A

2010-08-01

People's emotional states influence what they focus their attention on in their environment. For example, fear focuses people's attention on threats, whereas excitement may focus their attention on rewards. This study examined the effect of anger on overt visual attention to threats and rewards. Anger is an unpleasant emotion associated with approach motivation. If the effect of emotion on visual attention depends on valence, we would expect anger to focus people's attention on threats. If, however, the effect of emotion on visual attention depends on motivation, we would expect anger to focus people's attention on rewards. Using an eye tracker, we examined the effects of anger, fear, excitement, and a neutral emotional state on participants' overt visual attention to threatening, rewarding, and control images. We found that anger increased visual attention to rewarding information, but not to threatening information. These findings demonstrate that anger increases attention to potential rewards and suggest that the effects of emotions on visual attention are motivationally driven.

Neuronal basis of covert spatial attention in the frontal eye field.

PubMed

Thompson, Kirk G; Biscoe, Keri L; Sato, Takashi R

2005-10-12

The influential "premotor theory of attention" proposes that developing oculomotor commands mediate covert visual spatial attention. A likely source of this attentional bias is the frontal eye field (FEF), an area of the frontal cortex involved in converting visual information into saccade commands. We investigated the link between FEF activity and covert spatial attention by recording from FEF visual and saccade-related neurons in monkeys performing covert visual search tasks without eye movements. Here we show that the source of attention signals in the FEF is enhanced activity of visually responsive neurons. At the time attention is allocated to the visual search target, nonvisually responsive saccade-related movement neurons are inhibited. Therefore, in the FEF, spatial attention signals are independent of explicit saccade command signals. We propose that spatially selective activity in FEF visually responsive neurons corresponds to the mental spotlight of attention via modulation of ongoing visual processing.

Visual outcomes and prognostic factors in open-globe injuries.

PubMed

Fujikawa, Azusa; Mohamed, Yasser Helmy; Kinoshita, Hirofumi; Matsumoto, Makiko; Uematsu, Masafumi; Tsuiki, Eiko; Suzuma, Kiyoshi; Kitaoka, Takashi

2018-06-08

Ocular trauma is an important cause of visual loss worldwide. Improvements in our knowledge of the pathophysiology and management of ocular trauma during the past 30 years, in conjunction with advances in the instrumentation and techniques of ocular surgery, have improved the efficacy of vitreoretinal surgery in injured eyes. The aim of the current study was to determine the visual outcomes and prognostic factors of open-globe injuries in the Japanese population. Retrospective study of 59 eyes of 59 patients presented with open globe injuries between September 2008 and March 2014 at Nagasaki University Hospital was conducted. Demographic factors including age, gender, and clinical data such as cause of injury, presenting visual acuity (VA), location of injury, type of injury, lens status, presence of intraocular foreign body, types of required surgeries, and final VA were recorded. According to the classification of Ocular Trauma Classification Group, wound location was classified into three zones. Chi-square test was used to compare presented data. Out of the 59 patients, 46 were placed in the Light Perception (LP) group, and 13 were placed in the No Light Perception (NLP) group. Work-related trauma was the most common cause (27 eyes) followed by falls (19eyes). Work-related trauma was common in males (P = 0.004), while falls was significantly common in females (P = 0.00001). Zone III injuries had statistically significantly poor prognostic factor compared to other zones (P = 0.04). All cases of NLP group (100%) presented with rupture globe. Poor VA at first visit (P = 0.00001), rupture globe (P = 0.026), history of penetrating keratoplasty (PK) (P = 0.017), retinal detachment (RD) (P = 0.0001), vitreous hemorrhage (VH) (P = 0.044), and dislocation of crystalline lens (P = 0.0003) were considered as poor prognostic factors. Poor VA at first visit, rupture globe, zone III injuries, history of penetrating keratoplasty, RD, VH, and dislocation of crystalline lens were found to be poor prognostic factors. PPV had a good prognostic value in open globe injuries associated with posterior segment involvement.

Effects of visual attention on chromatic and achromatic detection sensitivities.

PubMed

Uchikawa, Keiji; Sato, Masayuki; Kuwamura, Keiko

2014-05-01

Visual attention has a significant effect on various visual functions, such as response time, detection and discrimination sensitivity, and color appearance. It has been suggested that visual attention may affect visual functions in the early visual pathways. In this study we examined selective effects of visual attention on sensitivities of the chromatic and achromatic pathways to clarify whether visual attention modifies responses in the early visual system. We used a dual task paradigm in which the observer detected a peripheral test stimulus presented at 4 deg eccentricities while the observer concurrently carried out an attention task in the central visual field. In experiment 1, it was confirmed that peripheral spectral sensitivities were reduced more for short and long wavelengths than for middle wavelengths with the central attention task so that the spectral sensitivity function changed its shape by visual attention. This indicated that visual attention affected the chromatic response more strongly than the achromatic response. In experiment 2 it was obtained that the detection thresholds increased in greater degrees in the red-green and yellow-blue chromatic directions than in the white-black achromatic direction in the dual task condition. In experiment 3 we showed that the peripheral threshold elevations depended on the combination of color-directions of the central and peripheral stimuli. Since the chromatic and achromatic responses were separately processed in the early visual pathways, the present results provided additional evidence that visual attention affects responses in the early visual pathways.

Vision improvement in pilots with presbyopia following perceptual learning.

PubMed

Sterkin, Anna; Levy, Yuval; Pokroy, Russell; Lev, Maria; Levian, Liora; Doron, Ravid; Yehezkel, Oren; Fried, Moshe; Frenkel-Nir, Yael; Gordon, Barak; Polat, Uri

2017-11-24

Israeli Air Force (IAF) pilots continue flying combat missions after the symptoms of natural near-vision deterioration, termed presbyopia, begin to be noticeable. Because modern pilots rely on the displays of the aircraft control and performance instruments, near visual acuity (VA) is essential in the cockpit. We aimed to apply a method previously shown to improve visual performance of presbyopes, and test whether presbyopic IAF pilots can overcome the limitation imposed by presbyopia. Participants were selected by the IAF aeromedical unit as having at least initial presbyopia and trained using a structured personalized perceptual learning method (GlassesOff application), based on detecting briefly presented low-contrast Gabor stimuli, under the conditions of spatial and temporal constraints, from a distance of 40 cm. Our results show that despite their initial visual advantage over age-matched peers, training resulted in robust improvements in various basic visual functions, including static and temporal VA, stereoacuity, spatial crowding, contrast sensitivity and contrast discrimination. Moreover, improvements generalized to higher-level tasks, such as sentence reading and aerial photography interpretation (specifically designed to reflect IAF pilots' expertise in analyzing noisy low-contrast input). In concert with earlier suggestions, gains in visual processing speed are plausible to account, at least partially, for the observed training-induced improvements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of myopes' visual acuity using stimuli with different contrast

NASA Astrophysics Data System (ADS)

Ikaunieks, G.; Caure, E.; Kassaliete, E.; Meskovska, Z.

2012-10-01

The influence of different contrast stimuli on the myopes’ visual acuity (VA) was studied using positive (35.7), negative (-0.97) and low contrast (-0.11) Landolt optotypes. Test subjects were 13 myopes with corrected eyesight and 8 emmetropes, all of them being 20-22 years old. For VA determination the FrACT computer program was employed. In the tests it was found that for emmetropes the positive and negative contrast VA values do not differ significantly, while for myopes the respective values are better with positive than with negative contrast stimuli. These differences were the same in the measurements taken with spectacles or contact lenses. Our results also show that the retinal straylight created by clean spectacles or soft contact lenses is similar in both cases. Dažu autoru pētījumi rāda, ka miopijas gadījumā redzes asums ir labāks ar pozitīva Vēbera kontrasta stimuliem (balts stimuls uz melna fona) nekā negatīva kontrasta stimuliem (melns stimuls uz balta fona). Šis fenomens tiek saistītas ar neirālām izmaiņām ON un OFF ceļos un miopiskās acīs. Citi pētījumi rāda, ka arī acī izkliedētās gaismas ietekmē labāks redzes asums ir ar pozitīviem kontrasta stimuliem nekā negatīva. Miopijas gadījumā papildus gaismas izkliedi rada briļļu lēcas vai kontaktlēcas. Mēs savā pētījumā vēlējāmies noskaidrot, cik lielā mērā labāks redzes asums ar pozitīva kontrasta stimuliem miopiskās acīs ir saistāms ar optiskās korekcijas radīto gaismas izkliedi. Pētījumā piedalījās 21 dalībnieks - 8 emetropi un 13 miopi ar sfērisko refrakcijas lielumu no -1.25 līdz -6,25 D. Dalībnieku vecums bija no 20 līdz 22 gadi. Izmantojot FrACT datorprogrammu, tika noteiks monokulārais redzes asums VA ar Landolta gredzeniem pie pozitīva, negatīva un zema kontrasta fotopiskos apstākļos. Vēbera kontrasti stimuliem attiecīgi bija 35.7, -0.97 un -0.11. Miopiem mērījumi tika veikti gan ar brillēm, gan kontaktlēcām. Emetropiem redzes asums pie pozitīva un negatīva kontrasta nav būtiski atšķirīgs, savukārt koriģētiem miopiem redzes asums bija labāks ar pozitīva nekā ar negatīva kontrasta stimuliem. Starpība mērījumos, veiktos ar kontaktlēcām, gan brillēm, nebija būtiski atšķirīga. No iegūtajiem rezultātiem var secināt, ka briļļu lēcas un kontaktlēcas rada līdzīgu acī 'noklīdušās” gaismas daudzumu.

Distance- and near-visual impairment in rural Chinese adults in Kailu, Inner Mongolia.

PubMed

Cheng, Fang; Shan, Li; Song, Wulian; Fan, Pan; Yuan, Huiping

2016-06-01

To investigate the prevalence and causes of distance-visual impairment and near-vision impairment in a rural Chinese population in Inner Mongolia. A population-based, cross-sectional study design was used to identify visual impairment in the Chinese aged 40 years and older living in Kailu County, Inner Mongolia. Low vision, blindness and near-visual impairment (NVI) were defined according to World Health Organization (WHO) criteria. The overall prevalence of blindness and visual impairment based on the presenting visual acuity (VA) was 2.2% (95% CI: 1.8-2.6) and 9.8% (95% CI: 8.9-10.6), respectively, and was adjusted to 0.9% (95% CI: 0.6-1.2) and 4.7% (95% CI: 4.1-5.3) using best-corrected visual acuity (BCVA), respectively. Taking the presenting VA into consideration, the leading cause of visual impairment and blindness was cataract (40.3%, 40.9%), followed by uncorrected refractive error (26.6%, 28.2%). According to the BCVA, the main cause of visual impairment and blindness was cataract (48.3%, 41.3%) followed by glaucoma (19.0%, 23.9%). Among the examined subjects, 80.3% had NVI, and 51.7% had presbyopia. Major barriers reported by NVI persons without near correction were lack of money to purchase prescription glasses and poor quality of the available ones (43.2%). Visual impairment is a serious public health problem, and the main causes leading to visual impairment are treatable and preventable in the rural Chinese population in Inner Mongolia. Presbyopia, together with the low rate of spectacles and lack of appropriate refractive and presbyopia spectacles, is highly prevalent in rural China. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Validation of an instrument to assess visual ability in children with visual impairment in China.

PubMed

Huang, Jinhai; Khadka, Jyoti; Gao, Rongrong; Zhang, Sifang; Dong, Wenpeng; Bao, Fangjun; Chen, Haisi; Wang, Qinmei; Chen, Hao; Pesudovs, Konrad

2017-04-01

To validate a visual ability instrument for school-aged children with visual impairment in China by translating, culturally adopting and Rasch scaling the Cardiff Visual Ability Questionnaire for Children (CVAQC). The 25-item CVAQC was translated into Mandarin using a standard protocol. The translated version (CVAQC-CN) was subjected to cognitive testing to ensure a proper cultural adaptation of its content. Then, the CVAQC-CN was interviewer-administered to 114 school-aged children and young people with visual impairment. Rasch analysis was carried out to assess its psychometric properties. The correlation between the CVAQC-CN visual ability scores and clinical measure of vision (visual acuity; VA and contrast sensitivity, CS) were assessed using Spearman's r. Based on cultural adaptation exercise, cognitive testing, missing data and Rasch metrics-based iterative item removal, three items were removed from the original 25. The 22-item CVAQC-CN demonstrated excellent measurement precision (person separation index, 3.08), content validity (item separation, 10.09) and item reliability (0.99). Moreover, the CVAQC-CN was unidimensional and had no item bias. The person-item map indicated good targeting of item difficulty to person ability. The CVAQC-CN had moderate correlations between CS (-0.53, p<0.00001) and VA (0.726, p<0.00001), respectively, indicating its validity. The 22-item CVAQC-CN is a psychometrically robust and valid instrument to measure visual ability in children with visual impairment in China. The instrument can be used as a clinical and research outcome measure to assess the change in visual ability after low vision rehabilitation intervention. 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/.

Modified Monovision With Spherical Aberration to Improve Presbyopic Through-Focus Visual Performance

PubMed Central

Zheleznyak, Len; Sabesan, Ramkumar; Oh, Je-Sun; MacRae, Scott; Yoon, Geunyoung

2013-01-01

Purpose. To investigate the impact on visual performance of modifying monovision with monocularly induced spherical aberration (SA) to increase depth of focus (DoF), thereby enhancing binocular through-focus visual performance. Methods. A binocular adaptive optics (AO) vision simulator was used to correct both eyes' native aberrations and induce traditional (TMV) and modified (MMV) monovision corrections. TMV was simulated with 1.5 diopters (D) of anisometropia (dominant eye at distance, nondominant eye at near). Zernike primary SA was induced in the nondominant eye in MMV. A total of four MMV conditions were tested with various amounts of SA (±0.2 and ±0.4 μm) and fixed anisometropia (1.5 D). Monocular and binocular visual acuity (VA) and contrast sensitivity (CS) at 10 cyc/deg and binocular summation were measured through-focus in three cyclopledged subjects with 4-mm pupils. Results. MMV with positive SA had a larger benefit for intermediate distances (1.5 lines at 1.0 D) than with negative SA, compared with TMV. Negative SA had a stronger benefit in VA at near. DoF of all MMV conditions was 3.5 ± 0.5 D (mean) as compared with TMV (2.7 ± 0.3 D). Through-focus CS at 10 cyc/deg was significantly reduced with MMV as compared to TMV only at intermediate object distances, however was unaffected at distance. Binocular summation was absent at all object distances except 0.5 D, where it improved in MMV by 19% over TMV. Conclusions. Modified monovision with SA improves through-focus VA and DoF as compared with traditional monovision. Binocular summation also increased as interocular similarity of image quality increased due to extended monocular DoF. PMID:23557742

Prevalence of uncorrected refractive errors, presbyopia and spectacle coverage in marine fishing communities in South India: Rapid Assessment of Visual Impairment (RAVI) project.

PubMed

Marmamula, Srinivas; Madala, Sreenivas R; Rao, Gullapalli N

2012-03-01

To investigate the prevalence of uncorrected refractive errors, presbyopia and spectacle coverage in subjects aged 40 years or more using a novel Rapid Assessment of Visual Impairment (RAVI) methodology. A population-based cross-sectional study was conducted using cluster random sampling to enumerate 1700 subjects from 34 clusters predominantly inhabited by marine fishing communities in the Prakasam district of Andhra Pradesh, India. Unaided, aided and pinhole visual acuity (VA) was assessed using a Snellen chart at a distance of 6 m. Near vision was assessed using an N notation chart. Uncorrected refractive error was defined as presenting VA < 6/18 and improving to ≥6/18 with pinhole. Uncorrected presbyopia was defined as binocular near vision worse than N8 in subjects with binocular distance VA ≥ 6/18. 1560 subjects (response rate - 92%) were available for examination. Of these, 54.6% were female and 10.1% were ≥70 years of age. Refractive error was present in 250 individuals. It was uncorrected in 179 (unmet need) and corrected in 71 (met need) individuals. Among 1094 individuals with no distance visual impairment, presbyopia was present in 494 individuals. It was uncorrected in 439 (unmet need) and corrected in 55 individuals (met need). Spectacle coverage was 28.4% for refractive errors and 11.1% for presbyopia. There is a high unmet need for uncorrected refractive errors and presbyopia among marine fishing communities in the Prakasam district of South India. The data from this study can now be used as a baseline prior to the commencement of eye care services in this region. Ophthalmic & Physiological Optics © 2012 The College of Optometrists.

Determinant Factors of Poor Visual Outcome After Ocular Trauma: A Retrospective Study in Central Sarawak, Malaysia.

PubMed

Yong, Geng-Yi; Pan, Shin-Wei; Humayun Akhter, Faisal; Law, Thomas Ngo-Hieng; Toh, Teck-Hock

2016-01-01

To study the demographic characteristics of ocular trauma in Central Sarawak and identify the determinant factors of poor visual outcome. A retrospective study of ocular trauma cases presenting at the referral hospital in 2013. Patients were identified and recruited from hospital records. Those presenting for follow-up review were excluded. Case records were retrieved and reviewed after recruitment. We studied 168 patients with 179 ocular injuries, of which 44% were work related. Compared with non-work-related cases, work-related cases were more likely to be male [odds ratio (OR), 19.7; 95% confidence interval (CI), 2.6-150.9] and foreign (OR, 18.0; 95% CI, 2.3-142.0). Open globe injuries constituted a higher percentage of impaired visual acuity (VA) during the first visit: 84.6% compared with 18.1% for closed globe injuries (OR, 25.0; 95% CI, 5.3-118.4; P < 0.001). Of the open globe injuries, 61.5% worsened or showed no improvement in VA after 3 months compared with closed globe injuries (28.9%) (OR, 3.9; 95% CI, 1.2-12.7; P = 0.015). Of cases presenting 7 or more days after trauma, 76.9% worsened or showed no improvement in VA after 3 months compared with those presenting in less than 7 days (27.7%) (OR, 8.7; 95% CI, 2.3-33.0; P < 0.001). Among those with work-related injuries, 23.1% had used eye protective devices (EPDs). Ocular injuries in Central Sarawak were predominantly work related, occurring at industrial premises, and involving males and foreigners. Both open globe injuries and a delay in seeking treatment resulted in significantly poorer visual outcomes.

Do Multielement Visual Tracking and Visual Search Draw Continuously on the Same Visual Attention Resources?

ERIC Educational Resources Information Center

Alvarez, George A.; Horowitz, Todd S.; Arsenio, Helga C.; DiMase, Jennifer S.; Wolfe, Jeremy M.

2005-01-01

Multielement visual tracking and visual search are 2 tasks that are held to require visual-spatial attention. The authors used the attentional operating characteristic (AOC) method to determine whether both tasks draw continuously on the same attentional resource (i.e., whether the 2 tasks are mutually exclusive). The authors found that observers…

Idiopathic Intracranial Hypertension-A Comparison of Clinical Characteristics Between 4 Medical Centers in Different Geographic Regions of the World.

PubMed

Rosenblatt, Amir; Klein, Ainat; Roemer, Ségolène; Borruat, François-Xavier; Meira, Dália; Silva, Marta; Gökçay, Figen; Çelebisoy, Neşe; Kesler, Anat

2016-09-01

Idiopathic intracranial hypertension (IIH) is a well-characterized syndrome, most commonly affecting obese women of childbearing age. Differences in its prevalence have been reported in various populations. The aim of this article was to determine whether differences in clinical presentation and management exist for patients with IIH between different regions the world. Retrospective database analysis of adult patients with IIH from 4 different neuro-ophthalmology clinics. The data collected included gender, age of onset, body mass index (BMI), lumbar puncture opening pressure, initial visual acuity (VA), initial visual field (VF) mean deviation (MD), pharmacological or surgical treatment, length of follow-up, final VA, and final VF MD. The study population consisted of 244 patients, with significant regional variations of female to male ratio. Overall, there was no significant difference regarding the age of diagnosis or the BMI. Acetazolamide was the first line of treatment in all groups but there was a difference between countries regarding second-line treatment, including the use of surgical interventions. Mean initial VA differed between groups but the final change in VA was the same among all the study groups. There are differences in IIH presentation, treatment, and response to therapy among different countries. International prospective studies involving multiple centers are needed to determine the potential influence of environmental and genetic factors on the development of IIH and to improve the management of this potentially blinding disorder.

Visual Analytics Tools for Sustainable Lifecycle Design: Current Status, Challenges, and Future Opportunities.

PubMed

Ramanujan, Devarajan; Bernstein, William Z; Chandrasegaran, Senthil K; Ramani, Karthik

2017-01-01

The rapid rise in technologies for data collection has created an unmatched opportunity to advance the use of data-rich tools for lifecycle decision-making. However, the usefulness of these technologies is limited by the ability to translate lifecycle data into actionable insights for human decision-makers. This is especially true in the case of sustainable lifecycle design (SLD), as the assessment of environmental impacts, and the feasibility of making corresponding design changes, often relies on human expertise and intuition. Supporting human sense-making in SLD requires the use of both data-driven and user-driven methods while exploring lifecycle data. A promising approach for combining the two is through the use of visual analytics (VA) tools. Such tools can leverage the ability of computer-based tools to gather, process, and summarize data along with the ability of human-experts to guide analyses through domain knowledge or data-driven insight. In this paper, we review previous research that has created VA tools in SLD. We also highlight existing challenges and future opportunities for such tools in different lifecycle stages-design, manufacturing, distribution & supply chain, use-phase, end-of-life, as well as life cycle assessment. Our review shows that while the number of VA tools in SLD is relatively small, researchers are increasingly focusing on the subject matter. Our review also suggests that VA tools can address existing challenges in SLD and that significant future opportunities exist.

Indocyanine Green Videoangiography for Surgery of a Ruptured Dissecting Aneurysm in the Precommunicating Anterior Cerebral Artery: A Technical Case Report.

PubMed

Nagai, Yasunori; Goto, Masanori; Toda, Hiroki; Nishida, Namiko; Yoshimoto, Naoya; Iwasaki, Koichi

2017-08-01

Indocyanine green videoangiography (ICG-VA) is an important intraoperative adjunct for saccular aneurysm surgery, but its efficacy in surgery for dissecting aneurysms has rarely been reported. The authors describe the usefulness of preclipping ICG-VA in a rare case of a ruptured dissecting aneurysm located at the precommunicating (A1) segment of the anterior cerebral artery. A 52-year-old woman, with no history of connective tissue diseases or vascular disorders, presented with sudden headache and convulsion. The CT scan showed that the patient had subarachnoid hemorrhage. Angiography showed a dissecting aneurysm in the left A1 segment of the anterior cerebral artery. Thus, the patient underwent trapping of the dissecting aneurysm. ICG-VA was used as an intraoperative adjunct before and after clipping. The preclipping ICG-VA showed the heterogeneously bright dissecting aneurysm and branching arteries even in the presence of hematoma. Preclipping ICG-VA may enhance the advantage of direct surgery for dissecting aneurysm by allowing visualization of the extent of the dissected vascular wall and the related branching arteries. ICG-VA can be an indispensable adjunct to minimize the compromise from the surgical treatment for intracranial dissecting aneurysms. Copyright © 2017 by the Congress of Neurological Surgeons

Auditory and Visual Attention Performance in Children With ADHD: The Attentional Deficiency of ADHD Is Modality Specific.

PubMed

Lin, Hung-Yu; Hsieh, Hsieh-Chun; Lee, Posen; Hong, Fu-Yuan; Chang, Wen-Dien; Liu, Kuo-Cheng

2017-08-01

This study explored auditory and visual attention in children with ADHD. In a randomized, two-period crossover design, 50 children with ADHD and 50 age- and sex-matched typically developing peers were measured with the Test of Various Attention (TOVA). The deficiency of visual attention is more serious than that of auditory attention in children with ADHD. On the auditory modality, only the deficit of attentional inconsistency is sufficient to explain most cases of ADHD; however, most of the children with ADHD suffered from deficits of sustained attention, response inhibition, and attentional inconsistency on the visual modality. Our results also showed that the deficit of attentional inconsistency is the most important indicator in diagnosing and intervening in ADHD when both auditory and visual modalities are considered. The findings provide strong evidence that the deficits of auditory attention are different from those of visual attention in children with ADHD.

Simultaneous Bilateral Cataract Surgery in Outreach Surgical Camps

PubMed Central

Giles, Kagmeni; Robert, Ebana Steve; Come, Ebana Mvogo; Wiedemann, Peter

2017-01-01

OBJECTIVES The aim of this study was to evaluate the safety and visual outcomes of simultaneous bilateral cataract surgery (SBCS) with intraocular lens implantation performed in outreach surgical eye camps. METHODS The medical records of 47 consecutive patients who underwent simultaneous bilateral small-incision cataract surgery between January 2010 and December 2015 in outreach surgical camps in rural Cameroon were reviewed. The measures included postoperative visual outcomes and intraoperative and postoperative complications. RESULTS Data from 94 eyes of 47 participants (30 men, 17 women; mean age: 60.93 ± 13.58 years, range: 45–80 years) were included in this study. The presented best visual acuity (VA) was less than 3/60 in 100% of the eyes. At the 4-week follow-up, 84.04% of the eyes showed increased VA of 1 line or more (P = .001). Of these, 71 (75.53%) achieved good VA (greater than 6/18). Intraoperative or postoperative complications occurred in 19 (20.21%) eyes. The most serious intraoperative complication was a posterior capsule rupture and vitreous loss (2 patients, 2 eyes). The postoperative complications included a transient elevation in the intraocular pressure (6 eyes), chronic corneal oedema (5 eyes), iris capture (3 eyes), lens decentration (2 eyes), and hyphema (1 eye). No cases of postoperative endophthalmitis were recorded. CONCLUSIONS Under the strict observation of endophthalmitis prophylaxis, SBCS is an option to reduce the cataract blindness backlog in rural areas of developing countries. PMID:28469481

Information management central to JCAHO surveys.

PubMed

2000-12-01

Hospitals preparing for Joint Commission surveys should pay close attention to improving organizational performance, says Eric Silfen, former chief medical officer at Reston (VA) Hospital Center, who now oversees the hospital's outcomes research division.

The Nakuru posterior segment eye disease study: methods and prevalence of blindness and visual impairment in Nakuru, Kenya.

PubMed

Mathenge, Wanjiku; Bastawrous, Andrew; Foster, Allen; Kuper, Hannah

2012-10-01

To estimate the prevalence of blindness and visual impairment (VI) in adults aged ≥50 years in the Nakuru district of Kenya and to identify sociodemographic risk factors for these conditions. We also sought to validate the Rapid Assessment of Avoidable Blindness (RAAB) methodology. There were 5010 subjects enumerated for this study. Of these, 4414 participants underwent examination, for a response rate of 88.1%. Cross-sectional, population-based survey. Cluster random samplings with probability proportionate to size procedures were used to select a representative cross-sectional sample of adults aged ≥50 years. Each participant was interviewed, had distance visual acuity (VA) measured with reduced logarithm of the minimal angle of resolution tumbling-E chart, underwent autorefraction, and thereby had measurements of presenting, uncorrected, and best-corrected VA. All participants, regardless of vision, underwent detailed ophthalmic examinations including slit-lamp assessment and dilated retinal photographs. Visual acuity of <6/12. A representative sample of 4414 adults were enumerated (response rate, 88.1%). The prevalence of blindness (VA < 3/60 in better eye) was 1.6% (95% confidence interval [CI], 1.2-2.1%) and of VI, 0.4% (95% CI, 0.3-0.7%); 8.1% (95% CI, 7.2-9.2%); and 5.1% (95% CI, 4.3-6.1%) were severely (<6/60-3/60), moderately (<6/18-6/60), or mildly (<6/12-6/18) visually impaired, respectively. Being male, having less education, having Kalenjin tribal origin, and being ≥80 years old were associated with increased blindness prevalence. Prevalence estimates were comparable to a RAAB performed in the same area 2 years earlier. This survey provides reliable estimates of blindness and VI prevalence in Nakuru. Older age and tribal origin were identified as predictors of these conditions. This survey validates the use of RAAB as a method of estimating blindness and VI prevalence. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Evaluation of a Public Child Eye Health Tertiary Facility for Pediatric Cataract in Southern Nigeria I: Visual Acuity Outcome

PubMed Central

Duke, Roseline E.; Adio, Adedayo; Oparah, Sidney K.; Odey, Friday; Eyo, Okon A.

2016-01-01

Purpose: A retrospective study of the outcome of congenital and developmental cataract surgery was conducted in a public child eye health tertiary facility in children <16 years of age in Southern Nigeria, as part of an evaluation. Materials and Method: Manual Small Incision Cataract Surgery with or without anterior vitrectomy was performed. The outcome measures were visual acuity (VA) and change (gain) in visual acuity. The age of the child at onset, duration of delay in presentation, ocular co-morbidity, non ocular co-morbidity, gender, and pre operative visual acuity were matched with postoperative visual acuity. A total of 66 children were studied for a period of six weeks following surgery. Results: Forty eight (72.7%) children had bilateral congenital cataracts and 18 (27.3%) children had bilateral developmental cataracts. There were 38(57.6%) males and 28 (42.4%) females in the study. Thirty Five (53%) children had good visual outcome (normal vision range 6/6/ -6/18) post-operatively. The number of children with blindness (vision <3/60) decreased from 61 (92.4%) pre-operatively to 4 (6.1%) post-operatively. Post operative complication occurred in 6.8% of cases six week after surgery. Delayed presentation had an inverse relationship with change (gain) in visual acuity (r = - 0.342; p-value = 0.005). Pre-operative visual acuity had a positive relationship with post operative change (gain) in visual acuity (r = 0.618; p-value = 0.000). Conclusion: Predictors of change in visual acuity in our study were; delayed presentation and pre-operative VA. Cataract surgery in children showed clinical benefit. PMID:27347247

Project DyAdd: Visual Attention in Adult Dyslexia and ADHD

ERIC Educational Resources Information Center

Laasonen, Marja; Salomaa, Jonna; Cousineau, Denis; Leppamaki, Sami; Tani, Pekka; Hokkanen, Laura; Dye, Matthew

2012-01-01

In this study of the project DyAdd, three aspects of visual attention were investigated in adults (18-55 years) with dyslexia (n = 35) or attention deficit/hyperactivity disorder (ADHD, n = 22), and in healthy controls (n = 35). Temporal characteristics of visual attention were assessed with Attentional Blink (AB), capacity of visual attention…

A probabilistic model of overt visual attention for cognitive robots.

PubMed

Begum, Momotaz; Karray, Fakhri; Mann, George K I; Gosine, Raymond G

2010-10-01

Visual attention is one of the major requirements for a robot to serve as a cognitive companion for human. The robotic visual attention is mostly concerned with overt attention which accompanies head and eye movements of a robot. In this case, each movement of the camera head triggers a number of events, namely transformation of the camera and the image coordinate systems, change of content of the visual field, and partial appearance of the stimuli. All of these events contribute to the reduction in probability of meaningful identification of the next focus of attention. These events are specific to overt attention with head movement and, therefore, their effects are not addressed in the classical models of covert visual attention. This paper proposes a Bayesian model as a robot-centric solution for the overt visual attention problem. The proposed model, while taking inspiration from the primates visual attention mechanism, guides a robot to direct its camera toward behaviorally relevant and/or visually demanding stimuli. A particle filter implementation of this model addresses the challenges involved in overt attention with head movement. Experimental results demonstrate the performance of the proposed model.

Vision in former very low birthweight young adults with and without retinopathy of prematurity compared with term born controls: the NZ 1986 VLBW follow-up study.

PubMed

Darlow, Brian A; Elder, Mark J; Kimber, Bridget; Martin, Julia; Horwood, L John

2017-12-06

There are few data on visual outcomes in adulthood of former very low birthweight (VLBW; <1500 g) infants. We aimed to assess vision at 27-29 years in a national cohort of VLBW infants born in 1986 and assessed for retinopathy of prematurity (ROP) when no treatment was available, compared with term born controls. The cohort and controls attended a 2-day assessment in Christchurch as part of a larger study. Visual assessment included glasses prescription measured by focimeter, logarithm of the minimum angle of resolution (logMAR) distance visual acuity (VA), contrast sensitivity, autorefraction, retinal photographs and a questionnaire on vision-related everyday activities. Rates of reduced VA and myopia in the VLBW cohort at 27-29 were compared with the results of vision testing at 7-8 years. 250 VLBW adults (77% those alive) gave study consent and 229 (45 with a history of ROP) were assessed in Christchurch, plus 100 term born controls. VLBW adults with ROP had reduced VA compared with no ROP and controls (mean logMAR score (SD); 0.003 (0.19), -0.021 (0.16), -0.078 (0.09), P=0.001). There were no differences in myopia (>2 D) between the groups but high myopia (>5 D) was confined to those with ROP. VLBW adults with ROP drove a car less often and had higher difficulties with everyday activities scores due to eyesight. Between 7-8 and 27-29 years rates of reduced VA were stable but myopia increased. Former VLBW young adults with ROP have ongoing problems with vision affecting daily living and should continue in regular ophthalmological review. ACTRN12612000995875, Pre-results . © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Accessibility and acceptability of the Department of Veteran Affairs health care: diverse veterans' perspectives.

PubMed

Damron-Rodriguez, JoAnn; White-Kazemipour, Whitney; Washington, Donna; Villa, Valentine M; Dhanani, Shawkat; Harada, Nancy D

2004-03-01

Diverse veteran's perspectives on the accessibility and acceptability of the Department of Veteran Affairs (VA) health services are presented. The qualitative methodology uses 16 focus groups (N = 178) stratified by war cohort (World War II and Korean Conflict versus Vietnam War and Persian Gulf War) and four ethnic/racial categories (African American, Asian American, European American, Hispanic American). Five themes emerged regarding veterans' health care expectations: (1) better information regarding available services, (2) sense of deserved benefits, (3) concern about welfare stigma, (4) importance of physician attentiveness, and (5) staff respect for patients as veterans. Although veterans' ethnic/racial backgrounds differentiated their military experiences, it was the informants' veteran identity that framed what they expected of VA health services. Accessibility and acceptability of VA health care is related to veterans' perspectives of the nature of their entitlement to service. Provider education and customer service strategies should consider the identified factors to increase access to VA as well as improve veterans' acceptance of the care.

Interactions between Visual Attention and Episodic Retrieval: Dissociable Contributions of Parietal Regions during Gist-Based False Recognition

PubMed Central

Guerin, Scott A.; Robbins, Clifford A.; Gilmore, Adrian W.; Schacter, Daniel L.

2012-01-01

SUMMARY The interaction between episodic retrieval and visual attention is relatively unexplored. Given that systems mediating attention and episodic memory appear to be segregated, and perhaps even in competition, it is unclear how visual attention is recruited during episodic retrieval. We investigated the recruitment of visual attention during the suppression of gist-based false recognition, the tendency to falsely recognize items that are similar to previously encountered items. Recruitment of visual attention was associated with activity in the dorsal attention network. The inferior parietal lobule, often implicated in episodic retrieval, tracked veridical retrieval of perceptual detail and showed reduced activity during the engagement of visual attention, consistent with a competitive relationship with the dorsal attention network. These findings suggest that the contribution of the parietal cortex to interactions between visual attention and episodic retrieval entails distinct systems that contribute to different components of the task while also suppressing each other. PMID:22998879

Prevalence and risk factors for visual impairment in preschool children the sydney paediatric eye disease study.

PubMed

Pai, Amy Shih-I; Wang, Jie Jin; Samarawickrama, Chameen; Burlutsky, George; Rose, Kathryn A; Varma, Rohit; Wong, Tien Yin; Mitchell, Paul

2011-08-01

To assess the prevalence and associations of visual impairment (VI) in preschool children. Cross-sectional, population-based study. A total of 2461 children (73.8% participation rate), aged 6 to 72 months, were examined in the Sydney Paediatric Eye Disease Study during 2007-2009; of whom 1188, aged 30 to 72 months, with complete visual acuity (VA) data in both eyes, were included in this report. Measurement of VA was attempted on all children using the Electronic Visual Acuity (EVA) system or a logarithm of the minimum angle of resolution (logMAR) chart. Visual impairment was defined as presenting VA <20/40 in children aged ≥48 months and <20/50 in those aged <48 months. Post-cycloplegic refraction was measured, and myopia was defined as spherical equivalent (SE) ≤-0.50 diopters (D), hyperopia was defined as SE ≥2.00 D, astigmatism was defined as cylinder ≥1.00 D, and anisometropia was defined as SE difference ≥1.00 D between 2 eyes. Ethnicity, birth parameters, and sociodemographic information were collected in questionnaires completed by parents. Visual impairment prevalence and its associations with child demographic factors and birth parameters. Visual impairment was found in 6.4% of the worse eye and 2.7% of the better eye in our sample. Refractive errors (69.7%) and amblyopia (26.3%) were the principal causes of VI in the worse eye. Astigmatism (51.3%) and hyperopia (28.9%) were the main refractive errors causing VI. In regression analysis controlling for other factors, VI was independently associated with low birthweight of <2500 g (odds ratio 2.4, 95% confidence interval, 1.1-5.3), but not with age, gender, ethnicity, or measures of socioeconomic status (P > 0.05). Visual impairment in at least 1 eye was found in 6.4% of Australian preschool children, with bilateral VI found in 2.7%. Uncorrected refractive errors and amblyopia were the principal ocular conditions associated with VI. Low birthweight was a significant risk factor independent of age, gender, and ethnicity. 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.

The King-Devick (K-D) test of rapid eye movements: a bedside correlate of disability and quality of life in MS.

PubMed

Moster, Stephen; Wilson, James A; Galetta, Steven L; Balcer, Laura J

2014-08-15

We investigated the King-Devick (K-D) test of rapid number naming as a visual performance measure in a cohort of patients with multiple sclerosis (MS). In this cross-sectional study, 81 patients with MS and 20 disease-free controls from an ongoing study of visual outcomes underwent K-D testing. A test of rapid number naming, K-D requires saccadic eye movements as well as intact vision, attention and concentration. To perform the K-D test, participants are asked to read numbers aloud as quickly as possible from three test cards; the sum of the three test card times in seconds constitutes the summary score. High-contrast visual acuity (VA), low-contrast letter acuity (1.25% and 2.5% levels), retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), MS Functional Composite (MSFC) and vision-specific quality of life (QOL) measures (25-Item NEI Visual Functioning Questionnaire [NEI-VFQ-25] and 10-Item Neuro-Ophthalmic Supplement) were also assessed. K-D time scores in the MS cohort (total time to read the three test cards) were significantly higher (worse) compared to those for disease-free controls (P=0.003, linear regression, accounting for age). Within the MS cohort, higher K-D scores were associated with worse scores for the NEI-VFQ-25 composite (P<0.001), 10-Item Neuro-Ophthalmic Supplement (P<0.001), binocular low-contrast acuity (2.5%, 1.25%, P<0.001, and high-contrast VA (P=0.003). Monocular low-contrast vision scores (P=0.001-0.009) and RNFL thickness (P=0.001) were also reduced in eyes of patients with worse K-D scores (GEE models accounting for age and within-patient, inter-eye correlations). Patients with a history of optic neuritis (ON) had increased (worse) K-D scores. Patients who classified their work disability status as disabled (receiving disability pension) did worse on K-D testing compared to those working full-time (P=0.001, accounting for age). The K-D test, a <2 minute bedside test of rapid number naming, is associated with visual dysfunction, neurologic impairment, and reduced vision-specific QOL in patients with MS. Scores reflect work disability as well as structural changes as measured by OCT imaging. History of ON and abnormal binocular acuities were associated with worse K-D scores, suggesting that abnormalities detected by K-D may go along with afferent dysfunction in MS patients. A brief test that requires saccadic eye movements, K-D should be considered for future MS trials as a rapid visual performance measure. Copyright © 2014 Elsevier B.V. All rights reserved.

USGS Scientific Visualization Laboratory

USGS Publications Warehouse

,

1995-01-01

The U.S. Geological Survey's (USGS) Scientific Visualization Laboratory at the National Center in Reston, Va., provides a central facility where USGS employees can use state-of-the-art equipment for projects ranging from presentation graphics preparation to complex visual representations of scientific data. Equipment including color printers, black-and-white and color scanners, film recorders, video equipment, and DOS, Apple Macintosh, and UNIX platforms with software are available for both technical and nontechnical users. The laboratory staff provides assistance and demonstrations in the use of the hardware and software products.

Threat captures attention but does not affect learning of contextual regularities.

PubMed

Yamaguchi, Motonori; Harwood, Sarah L

2017-04-01

Some of the stimulus features that guide visual attention are abstract properties of objects such as potential threat to one's survival, whereas others are complex configurations such as visual contexts that are learned through past experiences. The present study investigated the two functions that guide visual attention, threat detection and learning of contextual regularities, in visual search. Search arrays contained images of threat and non-threat objects, and their locations were fixed on some trials but random on other trials. Although they were irrelevant to the visual search task, threat objects facilitated attention capture and impaired attention disengagement. Search time improved for fixed configurations more than for random configurations, reflecting learning of visual contexts. Nevertheless, threat detection had little influence on learning of the contextual regularities. The results suggest that factors guiding visual attention are different from factors that influence learning to guide visual attention.

Feature-Based Memory-Driven Attentional Capture: Visual Working Memory Content Affects Visual Attention

ERIC Educational Resources Information Center

Olivers, Christian N. L.; Meijer, Frank; Theeuwes, Jan

2006-01-01

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by…

TMS over the right precuneus reduces the bilateral field advantage in visual short term memory capacity.

PubMed

Kraft, Antje; Dyrholm, Mads; Kehrer, Stefanie; Kaufmann, Christian; Bruening, Jovita; Kathmann, Norbert; Bundesen, Claus; Irlbacher, Kerstin; Brandt, Stephan A

2015-01-01

Several studies have demonstrated a bilateral field advantage (BFA) in early visual attentional processing, that is, enhanced visual processing when stimuli are spread across both visual hemifields. The results are reminiscent of a hemispheric resource model of parallel visual attentional processing, suggesting more attentional resources on an early level of visual processing for bilateral displays [e.g. Sereno AB, Kosslyn SM. Discrimination within and between hemifields: a new constraint on theories of attention. Neuropsychologia 1991;29(7):659-75.]. Several studies have shown that the BFA extends beyond early stages of visual attentional processing, demonstrating that visual short term memory (VSTM) capacity is higher when stimuli are distributed bilaterally rather than unilaterally. Here we examine whether hemisphere-specific resources are also evident on later stages of visual attentional processing. Based on the Theory of Visual Attention (TVA) [Bundesen C. A theory of visual attention. Psychol Rev 1990;97(4):523-47.] we used a whole report paradigm that allows investigating visual attention capacity variability in unilateral and bilateral displays during navigated repetitive transcranial magnetic stimulation (rTMS) of the precuneus region. A robust BFA in VSTM storage capacity was apparent after rTMS over the left precuneus and in the control condition without rTMS. In contrast, the BFA diminished with rTMS over the right precuneus. This finding indicates that the right precuneus plays a causal role in VSTM capacity, particularly in bilateral visual displays. Copyright © 2015 Elsevier Inc. All rights reserved.

Outcome of 5-Year Treatment of Neovascular Age-Related Macular Degeneration With Intravitreal Anti-VEGF Using "Treat and Extend" Regimen.

PubMed

Jaki Mekjavic, Polona; Zaletel Benda, Polona

2018-01-01

The aim of this study is twofold. First , to evaluate the long-term outcome of anti-vascular endothelial growth factor (anti-VEGF) treatment in a clinical setting using the "treat-and-extend regimen" (TER) in patients with neovascular age-related macular degeneration (nAMD). Second , to determine the proportion of patients treated with anti-VEGF with good visual acuity (VA), i.e., vision sufficient to maintain a high level of independence. We conducted a single center retrospective review of patients with treatment-naive nAMD who were treated with anti-VEGF. Patients were treated with anti-VEGF intravitreal injections according to the TER. Patients started treatment with monthly injections of either bevacizumab (1.25 mg/0.05 mL) or ranibizumab (0.5 mg/0.05 mL) until there were no signs present of choroidal neovascularization (CNV) activity. CNV activity was determined from fundus examination and SD-OCT imaging. Follow-up administration of intravitreal injections was extended by 2-week intervals, up to a total of 14 weeks, provided no signs of CNV activity were detected. In some patients, the first treatment was replaced with aflibercept (2 mg/0.05 mL). On the basis of the inclusion criterion for the study, that patients had to be treated for 5 years, a total of 101 patients were included in the study. In all patients, one eye was treated for a 5-year period, and thus we studied 101 eyes. Best corrected VA was analyzed at baseline and each year during the 5-year follow-up. VA improved initially after year 1 of the treatment. VA decreased in the subsequent 4 years of treatment, but remained significantly higher from year 1 to year 3 of the treatment compared to baseline values. Patients with good VA followed a similar trend: the proportion increased in the first year, and thereafter gradually decreased during the course of the 5-year follow up. At year 5, the number of patients with good VA decreased to baseline values. TER with anti-VEGF for nAMD treatment prevents long-term severe visual loss in real-world setting and maintains patients' VA at levels sufficient to ensure independence.

Five-Year Outcomes with Anti-Vascular Endothelial Growth Factor Treatment of Neovascular Age-Related Macular Degeneration: The Comparison of Age-Related Macular Degeneration Treatments Trials.

PubMed

Maguire, Maureen G; Martin, Daniel F; Ying, Gui-Shuang; Jaffe, Glenn J; Daniel, Ebenezer; Grunwald, Juan E; Toth, Cynthia A; Ferris, Frederick L; Fine, Stuart L

2016-08-01

To describe outcomes 5 years after initiating treatment with bevacizumab or ranibizumab for neovascular age-related macular degeneration (AMD). Cohort study. Patients enrolled in the Comparison of AMD Treatments Trials. Patients were assigned randomly to ranibizumab or bevacizumab and to 1 of 3 dosing regimens. After 2 years, patients were released from the clinical trial protocol. At 5 years, patients were recalled for examination. Visual acuity (VA) and morphologic retinal features. Visual acuity was obtained for 647 of 914 (71%) living patients with average follow-up of 5.5 years. The mean number of examinations for AMD care after the clinical trial ended was 25.3, and the mean number of treatments was 15.4. Most patients (60%) were treated 1 time or more with a drug other than their assigned drug. At the 5-year visit, 50% of eyes had VA of 20/40 or better and 20% had VA of 20/200 or worse. Mean change in VA was -3 letters from baseline and -11 letters from 2 years. Among 467 eyes with fluorescein angiography, mean total lesion area was 12.9 mm(2), a mean of 4.8 mm(2) larger than at 2 years. Geographic atrophy was present in 213 of 515 (41%) gradable eyes and was subfoveal in 85 eyes (17%). Among 555 eyes with spectral-domain optical coherence tomography, 83% had fluid (61% intraretinal, 38% subretinal, and 36% sub-retinal pigment epithelium). Mean foveal total thickness was 278 μm, a decrease of 182 μm from baseline and 20 μm from 2 years. The retina was abnormally thin (<120 μm) in 36% of eyes. Between 2 and 5 years, the group originally assigned to ranibizumab for 2 years lost more VA than the bevacizumab group (-4 letters; P = 0.008). Otherwise, there were no statistically significant differences in VA or morphologic outcomes between drug or regimen groups. Vision gains during the first 2 years were not maintained at 5 years. However, 50% of eyes had VA of 20/40 or better, confirming anti-vascular endothelial growth factor therapy as a major long-term therapeutic advance for neovascular AMD. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

A complete investigation of monocular and binocular functions in clinically treated amblyopia.

PubMed

Zhao, Wuxiao; Jia, Wu-Li; Chen, Ge; Luo, Yan; Lin, Borong; He, Qing; Lu, Zhong-Lin; Li, Min; Huang, Chang-Bing

2017-09-06

The gold standard of a successful amblyopia treatment is full recovery of visual acuity (VA) in the amblyopic eye, but there has been no systematic study on both monocular and binocular visual functions. In this research, we aimed to quantify visual qualities with a variety of perceptual tasks in subjects with treated amblyopia. We found near stereoacuity and pAE dominance in binocular rivalry in "treated" amblyopia were largely comparable to those of normal subjects. CSF of the pAE remained deficient in high spatial frequencies. The binocular contrast summation ratio is significantly lower than normal standard. The interocular balance point is 34%, indicating that contrast in pAE is much less effective as the same contrast in pFE in binocular phase combination. Although VA, stereoacuity and binocular rivalry at low spatial frequency in treated amblyopes were normal or nearly normal, the pAE remained "lazy" in high frequency domain, binocular contrast summation, and interocular phase combination. Our results suggest that structured monocular and binocular training are necessary to fully recover deficient functions in amblyopia.

Alcohol consumption and visual impairment in a rural Northern Chinese population.

PubMed

Li, Zhijian; Xu, Keke; Wu, Shubin; Sun, Ying; Song, Zhen; Jin, Di; Liu, Ping

2014-12-01

To investigate alcohol drinking status and the association between drinking patterns and visual impairment in an adult population in northern China. Cluster sampling was used to select samples. The protocol consisted of an interview, pilot study, visual acuity (VA) testing and a clinical examination. Visual impairment was defined as presenting VA worse than 20/60 in any eye. Drinking patterns included drinking quantity (standard drinks per week) and frequency (drinking days in the past week). Information on alcohol consumption was obtained from 8445 subjects, 963 (11.4%) of whom reported consuming alcohol. In multivariate analysis, alcohol consumption was significantly associated with older age (p < 0.001), male sex (p < 0.001), and higher education level (p < 0.01). Heavy intake (>14 drinks/week) was associated with higher odds of visual impairment. However, moderate intake (>1-14 drinks/week) was significantly associated with lower odds (adjusted odds ratio, OR, 0.7, 95% confidence interval, CI, 0.5-1.0) of visual impairment (p = 0.03). Higher drinking frequency was significantly associated with higher odds of visual impairment. Multivariate analysis showed that older age, male sex, and higher education level were associated with visual impairment among current drinkers. Age- and sex-adjusted ORs for the association of cataract and alcohol intake showed that higher alcohol consumption was not significantly associated with an increased prevalence of cataract (OR 1.2, 95% CI 0.4-3.6), whereas light and moderate alcohol consumption appeared to reduce incidence of cataract. Drinking patterns were associated with visual impairment. Heavy intake had negative effects on distance vision; meanwhile, moderate intake had a positive effect on distance vision.

The Influence of Selective and Divided Attention on Audiovisual Integration in Children.

PubMed

Yang, Weiping; Ren, Yanna; Yang, Dan Ou; Yuan, Xue; Wu, Jinglong

2016-01-24

This article aims to investigate whether there is a difference in audiovisual integration in school-aged children (aged 6 to 13 years; mean age = 9.9 years) between the selective attention condition and divided attention condition. We designed a visual and/or auditory detection task that included three blocks (divided attention, visual-selective attention, and auditory-selective attention). The results showed that the response to bimodal audiovisual stimuli was faster than to unimodal auditory or visual stimuli under both divided attention and auditory-selective attention conditions. However, in the visual-selective attention condition, no significant difference was found between the unimodal visual and bimodal audiovisual stimuli in response speed. Moreover, audiovisual behavioral facilitation effects were compared between divided attention and selective attention (auditory or visual attention). In doing so, we found that audiovisual behavioral facilitation was significantly difference between divided attention and selective attention. The results indicated that audiovisual integration was stronger in the divided attention condition than that in the selective attention condition in children. Our findings objectively support the notion that attention can modulate audiovisual integration in school-aged children. Our study might offer a new perspective for identifying children with conditions that are associated with sustained attention deficit, such as attention-deficit hyperactivity disorder. © The Author(s) 2016.

Vertebral artery injury in cervical spine surgery: anatomical considerations, management, and preventive measures.

PubMed

Peng, Chan W; Chou, Benedict T; Bendo, John A; Spivak, Jeffrey M

2009-01-01

Vertebral artery (VA) injury can be a catastrophic iatrogenic complication of cervical spine surgery. Although the incidence is rare, it has serious consequences including fistulas, pseudoaneurysm, cerebral ischemia, and death. It is therefore imperative to be familiar with the anatomy and the instrumentation techniques when performing anterior or posterior cervical spine surgeries. To provide a review of VA injury during common anterior and posterior cervical spine procedures with an evaluation of the surgical anatomy, management, and prevention of this injury. Comprehensive literature review. A systematic review of Medline for articles related to VA injury in cervical spine surgery was conducted up to and including journal articles published in 2007. The literature was then reviewed and summarized. Overall, the risk of VA injury during cervical spine surgery is low. In anterior cervical procedures, lateral dissection puts the VA at the most risk, so sound anatomical knowledge and constant reference to the midline are mandatory during dissection. With the development and rise in popularity of posterior cervical stabilization and instrumentation, recognition of the dangers of posterior drilling and insertion of transarticular screws and pedicle screws is important. Anomalous vertebral anatomy increases the risk of injury and preoperative magnetic resonance imaging and/or computed tomography (CT) scans should be carefully reviewed. When the VA is injured, steps should be taken to control local bleeding. Permanent occlusion or ligation should only be attempted if it is known that the contralateral VA is capable of providing adequate collateral circulation. With the advent of endovascular repair, this treatment option can be considered when a VA injury is encountered. VA injury during cervical spine surgery is a rare but serious complication. It can be prevented by careful review of preoperative imaging studies, having a sound anatomical knowledge and paying attention to surgical landmarks intraoperatively. When a VA injury occurs, prompt recognition and management are important.

Common neural substrates for visual working memory and attention.

PubMed

Mayer, Jutta S; Bittner, Robert A; Nikolić, Danko; Bledowski, Christoph; Goebel, Rainer; Linden, David E J

2007-06-01

Humans are severely limited in their ability to memorize visual information over short periods of time. Selective attention has been implicated as a limiting factor. Here we used functional magnetic resonance imaging to test the hypothesis that this limitation is due to common neural resources shared by visual working memory (WM) and selective attention. We combined visual search and delayed discrimination of complex objects and independently modulated the demands on selective attention and WM encoding. Participants were presented with a search array and performed easy or difficult visual search in order to encode one or three complex objects into visual WM. Overlapping activation for attention-demanding visual search and WM encoding was observed in distributed posterior and frontal regions. In the right prefrontal cortex and bilateral insula blood oxygen-level-dependent activation additively increased with increased WM load and attentional demand. Conversely, several visual, parietal and premotor areas showed overlapping activation for the two task components and were severely reduced in their WM load response under the condition with high attentional demand. Regions in the left prefrontal cortex were selectively responsive to WM load. Areas selectively responsive to high attentional demand were found within the right prefrontal and bilateral occipital cortex. These results indicate that encoding into visual WM and visual selective attention require to a high degree access to common neural resources. We propose that competition for resources shared by visual attention and WM encoding can limit processing capabilities in distributed posterior brain regions.

Recovery of Visual Search following Moderate to Severe Traumatic Brain Injury

PubMed Central

Schmitter-Edgecombe, Maureen; Robertson, Kayela

2015-01-01

Introduction Deficits in attentional abilities can significantly impact rehabilitation and recovery from traumatic brain injury (TBI). This study investigated the nature and recovery of pre-attentive (parallel) and attentive (serial) visual search abilities after TBI. Methods Participants were 40 individuals with moderate to severe TBI who were tested following emergence from post-traumatic amnesia and approximately 8-months post-injury, as well as 40 age and education matched controls. Pre-attentive (automatic) and attentive (controlled) visual search situations were created by manipulating the saliency of the target item amongst distractor items in visual displays. The relationship between pre-attentive and attentive visual search rates and follow-up community integration were also explored. Results The results revealed intact parallel (automatic) processing skills in the TBI group both post-acutely and at follow-up. In contrast, when attentional demands on visual search were increased by reducing the saliency of the target, the TBI group demonstrated poorer performances compared to the control group both post-acutely and 8-months post-injury. Neither pre-attentive nor attentive visual search slope values correlated with follow-up community integration. Conclusions These results suggest that utilizing intact pre-attentive visual search skills during rehabilitation may help to reduce high mental workload situations, thereby improving the rehabilitation process. For example, making commonly used objects more salient in the environment should increase reliance or more automatic visual search processes and reduce visual search time for individuals with TBI. PMID:25671675

Vitreoretinal surgery of the posterior segment for explosive trauma in terrorist warfare.

PubMed

Bajaire, Boris; Oudovitchenko, Elena; Morales, Edgar

2006-08-01

To describe surgical management and establish anatomic and visual results of patients with explosive ocular trauma in terrorist attacks treated with extreme vitreoretinal surgery. Retrospective study of clinical records (6-month follow-up) of patients with visual acuity (VA) of light perception or better with posterior segment injuries [vitreous hemorrhage, retinal detachment (RD), intra-ocular foreign bodies (IOFB), perforating trauma (PT)] from explosive weapons who underwent vitreoretinal surgery. We reviewed the demographic characteristics, type of weapon, time between injury and surgery, VA at arrival and 6 months after surgery, and type of trauma according to the International Trauma Classification. Fifty-seven out of 236 patients with ocular injuries from explosive weapons were included in the study; all of them were military men, average age 22 years (range 16-53 years). The average time between the blast and primary closing was 1 day, and 10 days between primary closing and vitreoretinal surgery. Open traumas by laceration accounted for 96% of cases and 4% were closed traumas; 76% of the eyes had IOFB, of which 18% involved PT; 5% had endophthalmitis. Contusion was the diagnosis for 100% of the closed traumas. Of the open traumas, 40% were localized at zone I, 44% at zone II, and 16% at zone III. Upon arrival, 98% of patients had VA 20/800-LP and 2% had >20/40. The patients with closed trauma had the injuries at zone III and presented VA 20/800-LP. All patients underwent posterior vitrectomy, scleral buckling, endotaponade and when required, lensectomy (82%), IOFB removal (72%), and/or retinectomy (25%). Postoperative VA improved in 43% of the patients, stabilized in 41% and evolved to NLP in 15% of the cases. Initial expressions of ocular trauma such as RD, PT and endophthalmitis suggest bad prognosis. We presented a series of patients with severe ocular trauma of the posterior segment from explosive weapons. These patients were treated according to our surgical protocol with extreme vitreoretinal surgery within the first 2 weeks after the blast; with our procedure we obtained stabilization or improvement of the VA for 84% of the cases.

Treatment for neovascular age-related macular degeneration in Sweden: outcomes at seven years in the Swedish Macula Register.

PubMed

Westborg, Inger; Granstam, Elisabet; Rosso, Aldana; Albrecht, Susanne; Karlsson, Niklas; Lövestam-Adrian, Monica

2017-12-01

To present Swedish Macula Register (SMR) data regarding treatment of neovascular age-related macular degeneration (AMD) in clinical practice since 2008. A retrospective register-based study was conducted. Evaluation of baseline demographics, visual outcome and number of injections during this period is presented. Mean age at diagnosis was 79 ± (SD) 8 years; 65% were female. The proportion of patients with <2 months' duration of symptoms increased from 26% in 2008 to 41% in 2014 (p = 0.001). Mean visual acuity (VA) at baseline increased from 54.3 ± 15.0 early treatment diabetic retinopathy study (ETDRS) letters in 2008 to 57.8 ± 15.6 letters in 2014 (CI 95 2.6; 4.3; p < 0.001). Mean VA after 1 year of treatment increased from 57.8 ± 17.7 ETDRS letters for patients who started the treatment in 2008 to 62.8 ± 16.4 ETDRS letters in patients starting treatment in 2014 (CI 95 2.67; 4.64; p < 0.001). During all study years, the proportion of patients with an improvement in VA of between 5 and 15 letters was around 30%, while 14% had VA improvement of more than 15 letters. The mean number of injections during the first treatment year increased from 4.3 ± 1.9 in 2008 to 5.9 ± 2.9 in 2014 (CI 95 1.40; 1.67; p < 0.001). Seven-year follow-up of 322 eyes showed a mean change of -1 letters from baseline, with a mean of 21 injections for the entire period. The duration of symptoms before treatment decreased, while VA at baseline and after 1 year of treatment increased over the years and so did the number of injections. Long-term follow-up demonstrated stable VA. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Infant Visual Attention and Object Recognition

PubMed Central

Reynolds, Greg D.

2015-01-01

This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. PMID:25596333

Outcomes of Anti-Vascular Endothelial Growth Factor Treatment for Choroidal Neovascularization in Fellow Eyes of Previously Treated Patients With Neovascular Age-Related Macular Degeneration.

PubMed

Stem, Maxwell S; Moinuddin, Omar; Kline, Noah; Thanos, Aristomenis; Rao, Prethy; Williams, George A; Hassan, Tarek S

2018-05-10

Neovascular age-related macular degeneration (nvAMD) is a leading cause of vision loss. The optimal screening protocol to detect choroidal neovascularization (CNV) in fellow eyes of patients undergoing treatment for unilateral CNV has not been determined. To compare the visual outcomes of eyes with established, active nvAMD in index eyes with outcomes of fellow eyes that subsequently developed CNV during the management protocol. In this retrospective single-center case series conducted at a private vitreoretinal practice, data were collected for all patients treated for bilateral nvAMD between October 1, 2015, and October 1, 2016, for whom we could determine the date of index eye and fellow eye conversion to nvAMD (n = 1600). Per institutional protocol, patients were screened for new CNV in the fellow eye at every office visit. Patients were excluded if they had a condition that could result in marked asymmetric vision loss. Development of nvAMD. Visual acuity (VA) at the time of diagnosis of nvAMD and at equivalent time points following conversion to nvAMD for both index eyes and fellow eyes. A total of 264 patients met the inclusion criteria; 197 (74.6%) were women and 253 (95.8%) were white, and the mean (SD) age was 79.1 (8.2) years at time of index eye conversion to nvAMD and 80.6 (8.2) years at time of fellow eye conversion to nvAMD. Fellow eyes presented with better VA (mean VA, 20/50 [0.40 logMAR]) compared with index eyes (mean VA, 20/90 [0.67 logMAR]) at the time of conversion (difference, 14 letters [0.27 logMAR]; 95% CI, 10-17 [0.20-0.34]; P < .001). Index eyes did not achieve the same level of VA as fellow eyes after an equivalent postconversion follow-up of approximately 20 months (mean VA: index eye; 20/70 [0.56 logMAR]; fellow eye, 20/50 [0.40 logMAR]; difference, 8 letters [0.15 logMAR]; 95% CI, 4-11 [0.08-0.22]; P < .001). No difference was detected between the mean number of anti-vascular endothelial growth factor injections received by fellow eyes and index eyes (9.7 vs 10.0 injections, respectively). This retrospective study suggests that fellow eyes of previously treated patients with nvAMD may achieve better VA than their index eye counterparts after an equivalent amount of follow-up. This may be because the CNV was detected and treated earlier and at a better level of VA, although it is unknown whether the frequent office visits, VA measurements, or optical coherence tomography testing was responsible for the detection at a better level of VA.

Auditory and Visual Capture during Focused Visual Attention

ERIC Educational Resources Information Center

Koelewijn, Thomas; Bronkhorst, Adelbert; Theeuwes, Jan

2009-01-01

It is well known that auditory and visual onsets presented at a particular location can capture a person's visual attention. However, the question of whether such attentional capture disappears when attention is focused endogenously beforehand has not yet been answered. Moreover, previous studies have not differentiated between capture by onsets…

Value-driven attentional capture in the auditory domain.

PubMed

Anderson, Brian A

2016-01-01

It is now well established that the visual attention system is shaped by reward learning. When visual features are associated with a reward outcome, they acquire high priority and can automatically capture visual attention. To date, evidence for value-driven attentional capture has been limited entirely to the visual system. In the present study, I demonstrate that previously reward-associated sounds also capture attention, interfering more strongly with the performance of a visual task. This finding suggests that value-driven attention reflects a broad principle of information processing that can be extended to other sensory modalities and that value-driven attention can bias cross-modal stimulus competition.

77 FR 65609 - Advisory Committee on Prosthetics and Special-Disabilities Programs; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-29

... the Secretary of Veterans Affairs on VA's prosthetics programs designed to provide state-of-the- art... program administered by the Secretary to serve Veterans with spinal cord injuries, blindness or visual...

78 FR 69176 - Advisory Committee on Prosthetics and Special-Disabilities Programs; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-18

... the Secretary of Veterans Affairs on VA's prosthetics programs designed to provide state-of-the- art... program administered by the Secretary to serve Veterans with spinal cord injuries, blindness or visual...

76 FR 60774 - Discontinuance of Form CO in Registration Practices

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

....e., Form TX for nondramatic literary works, Form PA for works of the performing arts, Form VA for works of visual art, Form SR for sound recordings, and Form SE for serials). Additionally, the proposed...

76 FR 21107 - Advisory Committee on Prosthetics and Special-Disabilities Programs; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-14

... the Secretary of Veterans Affairs on VA's prosthetics programs designed to provide state-of-the art... program administered by the Secretary to serve Veterans with spinal cord injuries, blindness or visual...

32 CFR Appendix A to Part 222 - Addressing MDR Requests

Code of Federal Regulations, 2013 CFR

2013-07-01

... Declassification Division, Suite 02F09-02, 4800 Mark Center Drive, Alexandria, VA 22350-3100. EXCEPTION: DoD...) Defense Logistics Agency. Defense Logistics Agency, Attention: DLA/DSS-S, 8725 John J. Kingman Road, Suite...

32 CFR Appendix A to Part 222 - Addressing MDR Requests

Code of Federal Regulations, 2012 CFR

2012-07-01

... Declassification Division, Suite 02F09-02, 4800 Mark Center Drive, Alexandria, VA22350-3100. EXCEPTION: DoD...) Defense Logistics Agency. Defense Logistics Agency, Attention: DLA/DSS-S, 8725 John J. Kingman Road, Suite...

32 CFR Appendix A to Part 222 - Addressing MDR Requests

Code of Federal Regulations, 2014 CFR

2014-07-01

... Declassification Division, Suite 02F09-02, 4800 Mark Center Drive, Alexandria, VA 22350-3100. EXCEPTION: DoD...) Defense Logistics Agency. Defense Logistics Agency, Attention: DLA/DSS-S, 8725 John J. Kingman Road, Suite...

Electrophysiological evidence for altered visual, but not auditory, selective attention in adolescent cochlear implant users.

PubMed

Harris, Jill; Kamke, Marc R

2014-11-01

Selective attention fundamentally alters sensory perception, but little is known about the functioning of attention in individuals who use a cochlear implant. This study aimed to investigate visual and auditory attention in adolescent cochlear implant users. Event related potentials were used to investigate the influence of attention on visual and auditory evoked potentials in six cochlear implant users and age-matched normally-hearing children. Participants were presented with streams of alternating visual and auditory stimuli in an oddball paradigm: each modality contained frequently presented 'standard' and infrequent 'deviant' stimuli. Across different blocks attention was directed to either the visual or auditory modality. For the visual stimuli attention boosted the early N1 potential, but this effect was larger for cochlear implant users. Attention was also associated with a later P3 component for the visual deviant stimulus, but there was no difference between groups in the later attention effects. For the auditory stimuli, attention was associated with a decrease in N1 latency as well as a robust P3 for the deviant tone. Importantly, there was no difference between groups in these auditory attention effects. The results suggest that basic mechanisms of auditory attention are largely normal in children who are proficient cochlear implant users, but that visual attention may be altered. Ultimately, a better understanding of how selective attention influences sensory perception in cochlear implant users will be important for optimising habilitation strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Endoresection with adjuvant ruthenium brachytherapy for selected uveal melanoma patients - the Tuebingen experience.

PubMed

Süsskind, Daniela; Dürr, Carina; Paulsen, Frank; Kaulich, Theodor; Bartz-Schmidt, Karl U

2017-12-01

To evaluate the treatment of selected patients with uveal melanoma with endoresection and adjuvant ruthenium brachytherapy. Thirty-five patients with uveal melanoma not suitable for ruthenium plaque monotherapy were treated with endoresection and adjuvant ruthenium brachytherapy between January 2001 and October 2013. Recurrence-free survival, globe retention, course of visual acuity (VA), occurrence of therapy-related complications and metastasis-free and overall survival were analysed retrospectively. Eight patients (22.9%) had a tumour recurrence after a median follow-up of 49.5 months (range: 21-134 months). Enucleation was necessary in eight patients. Thirty-two patients (91%) had a loss of VA with a median loss of nine lines (range: 0 to -39 lines); VA was stable in three patients and no patients had a gain in VA. Four patients (11.4%) developed radiation retinopathy. Metastases were detected in seven patients (20.0%) during follow-up. The occurrence of metastasis was significantly associated with monosomy 3 (p < 0.0001). Twenty-four patients (68.6%) were alive at the end of follow-up. Five patients (14.3%) died because of uveal melanoma (UM) metastasis. Endoresection with adjuvant ruthenium brachytherapy is an option for selected patients with UM who cannot be treated with brachytherapy as monotherapy. About two-thirds of eyes can be retained long term without recurrences. Visual acuity cannot be maintained in most cases, and may even decrease considerably. Radiation complications are comparatively rare and not a significant problem. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Cataract surgical outcomes from a large-scale micro-surgical campaign in China.

PubMed

Xiao, Baixiang; Guan, Chunhong; He, Yaling; Le Mesurier, Richard; Müller, Andreas; Limburg, Hans; Iezze, Beatrice

2013-10-01

To assess cataract surgical outcomes during the Jiangxi Provincial Government's "Brightness and Smile Initiative" (BSI) in South East China during May 2009 to July 2010. This cross sectional combined with retrospective study included 1157 cataract surgical patients (1254 eyes) recruited from six counties in Jiangxi during the initiative. Patient information before surgery and at discharge was obtained from hospitals' case records. Patient follow-up eye examinations were conducted during field visits in the autumn of 2010. Fifteen months after the initiative started, study subjects were examined by provincial ophthalmologists using a Snellen visual chart, portable slit lamp, torch and ophthalmoscope. The World Health Organization (WHO) cataract surgical outcome monitoring tally sheet and the outcome categories good (visual acuity, VA, ≥ 0.3 (6/18)), borderline (VA <0.3 but ≥ 0.1 (6/60)) and poor (VA < 0.1) were used for data collection and analysis. A total of 99.7% of operated patients had intraocular lenses implanted. The percentage of eyes with good outcomes (presenting VA) at follow-up was low (49.6%), while the borderline and poor outcome rates were high (34.1% and 16.3%, respectively), in comparison to WHO recommendations. There was a significant outcome difference at follow-up (p < 0.01) between eyes operated by county surgeons trained by an International Non-Government Organization and those operated on by other visiting surgeons. This study documented a low rate of good cataract surgical outcomes from the BSI in Jiangxi. The quality of cataract surgery should be improved further in the province.

Aging and Visual Attention

PubMed Central

Madden, David J.

2007-01-01

Older adults are often slower and less accurate than are younger adults in performing visual-search tasks, suggesting an age-related decline in attentional functioning. Age-related decline in attention, however, is not entirely pervasive. Visual search that is based on the observer’s expectations (i.e., top-down attention) is relatively preserved as a function of adult age. Neuroimaging research suggests that age-related decline occurs in the structure and function of brain regions mediating the visual sensory input, whereas activation of regions in the frontal and parietal lobes is often greater for older adults than for younger adults. This increased activation may represent an age-related increase in the role of top-down attention during visual tasks. To obtain a more complete account of age-related decline and preservation of visual attention, current research is beginning to explore the relation of neuroimaging measures of brain structure and function to behavioral measures of visual attention. PMID:18080001

A Componential Analysis of Visual Attention in Children With ADHD.

PubMed

McAvinue, Laura P; Vangkilde, Signe; Johnson, Katherine A; Habekost, Thomas; Kyllingsbæk, Søren; Bundesen, Claus; Robertson, Ian H

2015-10-01

Inattentive behaviour is a defining characteristic of ADHD. Researchers have wondered about the nature of the attentional deficit underlying these symptoms. The primary purpose of the current study was to examine this attentional deficit using a novel paradigm based upon the Theory of Visual Attention (TVA). The TVA paradigm enabled a componential analysis of visual attention through the use of a mathematical model to estimate parameters relating to attentional selectivity and capacity. Children's ability to sustain attention was also assessed using the Sustained Attention to Response Task. The sample included a comparison between 25 children with ADHD and 25 control children aged 9-13. Children with ADHD had significantly impaired sustained attention and visual processing speed but intact attentional selectivity, perceptual threshold and visual short-term memory capacity. The results of this study lend support to the notion of differential impairment of attentional functions in children with ADHD. © 2012 SAGE Publications.

Comparing the stress change characteristics and aftershock decay rate of the 2011 Mineral, VA, earthquake with similar earthquakes from a variety of tectonic settings

NASA Astrophysics Data System (ADS)

Walsh, L. S.; Montesi, L. G.; Sauber, J. M.; Watters, T. R.; Kim, W.; Martin, A. J.; Anderson, R.

2011-12-01

On August 23, 2011, the magnitude 5.8 Mineral, VA, earthquake rocked the U.S. national capital region (Washington, DC) drawing worldwide attention to the occurrence of intraplate earthquakes. Using regional Coulomb stress change, we evaluate to what extent slip on faults during the Mineral, VA, earthquake and its aftershocks may have increased stress on notable Cenozoic fault systems in the DC metropolitan area: the central Virginia seismic zone, the DC fault zone, and the Stafford fault system. Our Coulomb stress maps indicate that the transfer of stress from the Mineral, VA, mainshock was at least 500 times greater than that produced from the magnitude 3.4 Germantown, MD, earthquake that occurred northwest of DC on July 16, 2010. Overall, the Mineral, VA, earthquake appears to have loaded faults of optimum orientation in the DC metropolitan region, bringing them closer to failure. The distribution of aftershocks of the Mineral, VA, earthquake will be compared with Coulomb stress change maps. We further characterize the Mineral, VA, earthquake by comparing its aftershock decay rate with that of blind thrust earthquakes with similar magnitude, focal mechanism, and depth from a variety of tectonic settings. In particular, we compare aftershock decay relations of the Mineral, VA, earthquake with two well studied California reverse faulting events, the August 4, 1985 Kettleman Hills (Mw = 6.1) and October 1, 1987 Whittier Narrow (Mw = 5.9) earthquakes. Through these relations we test the hypothesis that aftershock duration is inversely proportional to fault stressing rate, suggesting that aftershocks in active tectonic margins may last only a few years while aftershocks in intraplate regions could endure for decades to a century.

Visual attention shifting in autism spectrum disorders.

PubMed

Richard, Annette E; Lajiness-O'Neill, Renee

2015-01-01

Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be related to restricted and repetitive behaviors in these disorders.

Clinical color vision testing and correlation with visual function.

PubMed

Zhao, Jiawei; Davé, Sarita B; Wang, Jiangxia; Subramanian, Prem S

2015-09-01

To determine if Hardy-Rand-Rittler (H-R-R) and Ishihara testing are accurate estimates of color vision in subjects with acquired visual dysfunction. Assessment of diagnostic tools. Twenty-two subjects with optic neuropathy (aged 18-65) and 18 control subjects were recruited prospectively from an outpatient clinic. Individuals with visual acuity (VA) <20/200 or with congenital color blindness were excluded. All subjects underwent a comprehensive eye examination including VA, color vision, and contrast sensitivity testing. Color vision was assessed using H-R-R and Ishihara plates and Farnsworth D-15 (D-15) discs. D-15 is the accepted standard for detecting and classifying color vision deficits. Contrast sensitivity was measured using Pelli-Robson contrast sensitivity charts. No relationship was found between H-R-R and D-15 scores (P = .477). H-R-R score and contrast sensitivity were positively correlated (P = .003). On multivariate analysis, contrast sensitivity (β = 8.61, P < .001) and VA (β = 2.01, P = .022) both showed association with H-R-R scores. Similar to H-R-R, Ishihara score did not correlate with D-15 score (P = .973), but on multivariate analysis was related to contrast sensitivity (β = 8.69, P < .001). H-R-R and Ishihara scores had an equivalent relationship with contrast sensitivity (P = .069). Neither H-R-R nor Ishihara testing appears to assess color identification in patients with optic neuropathy. Both H-R-R and Ishihara testing are correlated with contrast sensitivity, and these tests may be useful clinical surrogates for contrast sensitivity testing. Copyright © 2015 Elsevier Inc. All rights reserved.

Efficiency of occlusion therapy for management of amblyopia in older children.

PubMed

Brar, Gagandeep S; Bandyopadhyay, Supratik; Kaushik, Sushmita; Raj, Surishti

2006-12-01

To analyse results of full time occlusion therapy for amblyopia in children older than 6 years. This was a retrospective consecutive case series analysis of children treated for amblyopia at a tertiary care center. All children received full time occlusion (FTO) for the dominant eye. Eighty-eight children older than 6 years at the time of initiation of therapy were included. Age at initiation of therapy ranged from 6 to 20 years (9.45 +/- 3.11 years). Forty-two children (47.7%) had strabismic amblyopia, 37 (42.0%) had anisometropic amblyopia and 9 (10.2%) had a combination of strabismic and anisometropic amblyopia. Eighty out of 88 eyes (90.0%) had improvement in visual acuity following FTO. Visual acuity (VA) improved from 0.82 +/- 0.34 at presentation to 0.42 +/- 0.34 (P < 0.001) after FTO. In children with strabismic amblyopia, VA improved from 0.81 +/- 0.42 to 0.42 +/- 0.39 (P <0.001). In children with anisometropic amblyopia, visual acuity of the amblyopic eye improved fron 0.82 +/- 0.24 to 0.36 +/- 0.29 (P< 0.001) following FTO. Out of 13 children older than 12 years, only 6 children (46.1%) had improvement in VA. Mean follow-up after complete stoppage of occlusion was 8.37 +/- 1.78 months. Occlusion therapy yields favorable results in strabismic and/or anisometropic amblyopia, even when initiated for the first time after 6 years of age. After 12 years of age, some children may still respond to occlusion of the dominant eye.

Alternating Bi-Weekly Intravitreal Ranibizumab and Bevacizumab for Refractory Neovascular Age-Related Macular Degeneration with Pigment Epithelial Detachment.

PubMed

Witkin, Andre J; Rayess, Nadim; Garg, Sunir J; Maguire, Joseph I; Storey, Philip; Kaiser, Richard S; Hsu, Jason; Vander, James F; Ho, Allen C

2017-01-01

To describe visual and anatomical outcomes following bi-weekly intravitreal ranibizumab/bevacizumab injections in eyes with refractory neovascular age-related macular degeneration (AMD) and pigment epithelial detachment (PED). Retrospective, consecutive, interventional case series. Eighteen patients diagnosed with neovascular AMD that were refractory to anti-VEGF therapy and received alternating biweekly ranibizumab/bevacizumab injections were included. Patients with neovascular AMD and PED that were refractory to at least 11 monthly ranibizumab or bevacizumab injections were included in this study at a large, single retina practice. Following inclusion, patients received four bi-weekly alternating ranibizumab/bevacizumab intravitreal injections. After completing a course of four bi-weekly injections, patients were treated with variable regimens of intravitreal anti-vascular endothelial growth factor (VEGF) therapy. The primary outcomes of the study included change in visual acuity (VA) and central foveal thickness (CFT) at eight weeks follow-up. Study eyes had previously received a mean of 22 intravitreal anti-VEGF injections. At enrollment, mean VA was 20/95 and mean CFT was 455 µm. After four bi-weekly anti-VEGF injections, mean VA improved to 20/65 (p < 0.001), and mean CFT decreased to 387 µm (p = 0.029). In patients with PED, there was a mean 27.9% reduction in height (p = 0.046) at eight weeks' follow-up. Four injections of bi-weekly alternating ranibizumab/bevacizumab improved visual acuity and reduced macular thickness in a number of patients with refractory neovascular AMD and PED.

Active listening impairs visual perception and selectivity: an ERP study of auditory dual-task costs on visual attention.

PubMed

Gherri, Elena; Eimer, Martin

2011-04-01

The ability to drive safely is disrupted by cell phone conversations, and this has been attributed to a diversion of attention from the visual environment. We employed behavioral and ERP measures to study whether the attentive processing of spoken messages is, in itself, sufficient to produce visual-attentional deficits. Participants searched for visual targets defined by a unique feature (Experiment 1) or feature conjunction (Experiment 2), and simultaneously listened to narrated text passages that had to be recalled later (encoding condition), or heard backward-played speech sounds that could be ignored (control condition). Responses to targets were slower in the encoding condition, and ERPs revealed that the visual processing of search arrays and the attentional selection of target stimuli were less efficient in the encoding relative to the control condition. Results demonstrate that the attentional processing of visual information is impaired when concurrent spoken messages are encoded and maintained, in line with cross-modal links in selective attention, but inconsistent with the view that attentional resources are modality-specific. The distraction of visual attention by active listening could contribute to the adverse effects of cell phone use on driving performance.

Object-based attention underlies the rehearsal of feature binding in visual working memory.

PubMed

Shen, Mowei; Huang, Xiang; Gao, Zaifeng

2015-04-01

Feature binding is a core concept in many research fields, including the study of working memory (WM). Over the past decade, it has been debated whether keeping the feature binding in visual WM consumes more visual attention than the constituent single features. Previous studies have only explored the contribution of domain-general attention or space-based attention in the binding process; no study so far has explored the role of object-based attention in retaining binding in visual WM. We hypothesized that object-based attention underlay the mechanism of rehearsing feature binding in visual WM. Therefore, during the maintenance phase of a visual WM task, we inserted a secondary mental rotation (Experiments 1-3), transparent motion (Experiment 4), or an object-based feature report task (Experiment 5) to consume the object-based attention available for binding. In line with the prediction of the object-based attention hypothesis, Experiments 1-5 revealed a more significant impairment for binding than for constituent single features. However, this selective binding impairment was not observed when inserting a space-based visual search task (Experiment 6). We conclude that object-based attention underlies the rehearsal of binding representation in visual WM. (c) 2015 APA, all rights reserved.

Visual acuity, contrast sensitivity, and range performance with compressed motion video

NASA Astrophysics Data System (ADS)

Bijl, Piet; de Vries, Sjoerd C.

2010-10-01

Video of visual acuity (VA) and contrast sensitivity (CS) test charts in a complex background was recorded using a CCD color camera mounted on a computer-controlled tripod and was fed into real-time MPEG-2 compression/decompression equipment. The test charts were based on the triangle orientation discrimination (TOD) test method and contained triangle test patterns of different sizes and contrasts in four possible orientations. In a perception experiment, observers judged the orientation of the triangles in order to determine VA and CS thresholds at the 75% correct level. Three camera velocities (0, 1.0, and 2.0 deg/s, or 0, 4.1, and 8.1 pixels/frame) and four compression rates (no compression, 4 Mb/s, 2 Mb/s, and 1 Mb/s) were used. VA is shown to be rather robust to any combination of motion and compression. CS, however, dramatically decreases when motion is combined with high compression ratios. The measured thresholds were fed into the TOD target acquisition model to predict the effect of motion and compression on acquisition ranges for tactical military vehicles. The effect of compression on static performance is limited but strong with motion video. The data suggest that with the MPEG2 algorithm, the emphasis is on the preservation of image detail at the cost of contrast loss.

Effect of Grade I and II Intraventricular Hemorrhage on Visuocortical Function in Very Low Birth Weight Infants

PubMed Central

Madan, Ashima; Norcia, Anthony M.; Hou, Chuan; Pettet, Mark W.; Good, William V.

2015-01-01

The neurological outcome for infants with Grade I/II intraventricular hemorrhage (IVH) is debated. The aim of this study was to determine whether very low birth weight infants (VLBW, < 1500 g) with Grade I /II (IVH) have altered visuocortical activity compared with infants with no IVH. We assessed the quantitative swept parameter Visual Evoked Potential (sVEP) responses evoked by three different visual stimuli. Data from 52 VLBW infants were compared with data from 13 infants with Grade I or II IVH, enrolled at 5 – 7 months corrected age. Acuity thresholds and suprathreshold response amplitudes were compared. Grating Acuity (GA), Contrast Sensitivity (CS) and Vernier Acuity (VA) were each worse in the Grade I/ II IVH compared with the no IVH groups (8.24 cpd in IVH group vs 13.07 cpd in no IVH group for GA; 1.44% vs 1.18% for CS and 1.55 arcmin vs 0.58 arcmin for VA). The slopes of the response amplitude for CS and VA were significantly lower in IVH infants. The spatial frequency tuning function was shifted downward on the spatial frequency axis, without a change in slope. These results indicate that Grade I/II IVH are associated with deleterious effects on cortical vision development and function. PMID:22371027

Coats' disease with macular oedema responsive to aflibercept and argon laser.

PubMed

Guixeres Esteve, M C; Pardo Saiz, A O

2017-07-01

A 14 year-old boy with Coats' disease in his right eye, presented with a visual acuity (VA) of 0.1, micro-aneurysms, exudates, a macular oedema of 959 microns, and peripheral telangiectasias. After 12 months follow-up with 6 ranibizumab injections and 3 sessions of argon laser photocoagulation, the macular oedema remained and VA was 0.2. Following 4 aflibercept injections and another 2 laser sessions, he had a good foveal slope and a VA of 0.5, with no recurrences in the last 12 months. Treatment with aflibercept and argon laser was effective in our patient with stage 2B Coats' disease and macular oedema unresponsive to ranibizumab. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Optical Coherence Tomographic and Visual Results at Six Months after Transitioning to Aflibercept for Patients on Prior Ranibizumab or Bevacizumab Treatment for Exudative Age-Related Macular Degeneration (An American Ophthalmological Society Thesis)

PubMed Central

Chan, Clement K.; Jain, Atul; Sadda, Srinivas; Varshney, Neeta

2014-01-01

Purpose: To study optical coherence tomographic (OCT) results and vision at 6 months after transition (post-Tx) from intravitreal bevacizumab and/or ranibizumab to aflibercept for treatment of neovascular age-related macular degeneration (nAMD). The null hypothesis was the lack of improvements in OCT metrics and vision outcome in study eyes at 6 months after transitioning from bevacizumab or ranibizumab to aflibercept. Methods: This retrospective study assessed 6 monthly OCT (Cirrus) data after transitioning to aflibercept for eyes on prior Legacy-ranibizumab, Legacy-bevacizumab, or mixed treatment for nAMD. Outcome measures were subretinal fluid (SRF), cystoid macular edema (CME), pigment epithelial detachment (PED) heights and volumes, central 1- and 3-mm subfield, Macular Volume, and best spectacle and pinhole visual acuity (VA). A single masked investigator performed all OCT measurements. Results: One hundred eighty-nine eyes in 172 patients in Legacy-bevacizumab (95 eyes), Legacy-ranibizumab (84 eyes), or Mixed Group(10 eyes) were switched to aflibercept and followed for 6 months. Significant post-Tx reductions were noted in SRF/CME heights and volumes (all P<.001). Similar findings were noted for PED heights (122.8 μm vs 79.4 μm) and PED volumes (all P<.001). Post-Tx VA was better (20/43 vs 20/51, P<.001). There were no differences between Legacy-bevacizumab and Legacy-ranibizumab groups in OCT and VA changes. Post-Tx VA, SRF/CME, and PED heights and volumes were improved for Nonresponders (suboptimal response to bevacizumab/ranibizumab) (P=.001 to <.001), but not Responders (good responses to same). The only adverse event was a retinal pigment epithelial tear in one eye. Conclusions: Significant improvements in vision and OCT metrics developed in Nonresponders but not in Responders. Post-Tx VA and OCT measures were similar for eyes on prior bevacizumab or ranibizumab. Post-Tx adverse events were uncommon. PMID:25646034

Transient effects of harsh luminous conditions on the visual performance of aviators in a civil aircraft cockpit.

PubMed

Yang, Biao; Lin, Yandan; Sun, Yaojie

2013-03-01

The aim of this work was to examine how harsh luminous conditions in a cockpit, such as lightning in a thunderstorm or direct sunlight immediately after an aircraft passes through clouds, may affect the visual performance of pilots, and how to improve it. Such lighting conditions can result in the temporary visual impairment of aviators, which may greatly increase the risk of accidents. Tests were carried out in a full-scale simulator cockpit in which two kinds of dynamic lighting scenes, namely pulse changed and step changed lighting, were used to represent harsh luminous conditions. Visual acuity (VA), reaction time (RT) and identification accuracy (IA) were recorded as dependent variables. Data analysis results indicate that standardized VA values decreased significantly in both pulsing and step conditions in comparison with the dark condition. Standardized RT values increased significantly in the step condition; on the contrary, less reaction time was observed in the pulsing condition. Such effects could be reduced by an ambient illumination provided by a fluorescent lamp in both conditions. The results are to be used as a principle for optimizing lighting design with a thunderstorm light. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Changes in the distribution of sustained attention alter the perceived structure of visual space.

PubMed

Fortenbaugh, Francesca C; Robertson, Lynn C; Esterman, Michael

2017-02-01

Visual spatial attention is a critical process that allows for the selection and enhanced processing of relevant objects and locations. While studies have shown attentional modulations of perceived location and the representation of distance information across multiple objects, there remains disagreement regarding what influence spatial attention has on the underlying structure of visual space. The present study utilized a method of magnitude estimation in which participants must judge the location of briefly presented targets within the boundaries of their individual visual fields in the absence of any other objects or boundaries. Spatial uncertainty of target locations was used to assess perceived locations across distributed and focused attention conditions without the use of external stimuli, such as visual cues. Across two experiments we tested locations along the cardinal and 45° oblique axes. We demonstrate that focusing attention within a region of space can expand the perceived size of visual space; even in cases where doing so makes performance less accurate. Moreover, the results of the present studies show that when fixation is actively maintained, focusing attention along a visual axis leads to an asymmetrical stretching of visual space that is predominantly focused across the central half of the visual field, consistent with an expansive gradient along the focus of voluntary attention. These results demonstrate that focusing sustained attention peripherally during active fixation leads to an asymmetrical expansion of visual space within the central visual field. Published by Elsevier Ltd.

Higher dietary diversity is related to better visual and auditory sustained attention.

PubMed

Shiraseb, Farideh; Siassi, Fereydoun; Qorbani, Mostafa; Sotoudeh, Gity; Rostami, Reza; Narmaki, Elham; Yavari, Parvaneh; Aghasi, Mohadeseh; Shaibu, Osman Mohammed

2016-04-01

Attention is a complex cognitive function that is necessary for learning, for following social norms of behaviour and for effective performance of responsibilities and duties. It is especially important in sensitive occupations requiring sustained attention. Improvement of dietary diversity (DD) is recognised as an important factor in health promotion, but its association with sustained attention is unknown. The aim of this study was to determine the association between auditory and visual sustained attention and DD. A cross-sectional study was carried out on 400 women aged 20-50 years who attended sports clubs at Tehran Municipality. Sustained attention was evaluated on the basis of the Integrated Visual and Auditory Continuous Performance Test using Integrated Visual and Auditory software. A single 24-h dietary recall questionnaire was used for DD assessment. Dietary diversity scores (DDS) were determined using the FAO guidelines. The mean visual and auditory sustained attention scores were 40·2 (sd 35·2) and 42·5 (sd 38), respectively. The mean DDS was 4·7 (sd 1·5). After adjusting for age, education years, physical activity, energy intake and BMI, mean visual and auditory sustained attention showed a significant increase as the quartiles of DDS increased (P=0·001). In addition, the mean subscales of attention, including auditory consistency and vigilance, visual persistence, visual and auditory focus, speed, comprehension and full attention, increased significantly with increasing DDS (P<0·05). In conclusion, higher DDS is associated with better visual and auditory sustained attention.

Spatial and Feature-Based Attention in a Layered Cortical Microcircuit Model

PubMed Central

Wagatsuma, Nobuhiko; Potjans, Tobias C.; Diesmann, Markus; Sakai, Ko; Fukai, Tomoki

2013-01-01

Directing attention to the spatial location or the distinguishing feature of a visual object modulates neuronal responses in the visual cortex and the stimulus discriminability of subjects. However, the spatial and feature-based modes of attention differently influence visual processing by changing the tuning properties of neurons. Intriguingly, neurons' tuning curves are modulated similarly across different visual areas under both these modes of attention. Here, we explored the mechanism underlying the effects of these two modes of visual attention on the orientation selectivity of visual cortical neurons. To do this, we developed a layered microcircuit model. This model describes multiple orientation-specific microcircuits sharing their receptive fields and consisting of layers 2/3, 4, 5, and 6. These microcircuits represent a functional grouping of cortical neurons and mutually interact via lateral inhibition and excitatory connections between groups with similar selectivity. The individual microcircuits receive bottom-up visual stimuli and top-down attention in different layers. A crucial assumption of the model is that feature-based attention activates orientation-specific microcircuits for the relevant feature selectively, whereas spatial attention activates all microcircuits homogeneously, irrespective of their orientation selectivity. Consequently, our model simultaneously accounts for the multiplicative scaling of neuronal responses in spatial attention and the additive modulations of orientation tuning curves in feature-based attention, which have been observed widely in various visual cortical areas. Simulations of the model predict contrasting differences between excitatory and inhibitory neurons in the two modes of attentional modulations. Furthermore, the model replicates the modulation of the psychophysical discriminability of visual stimuli in the presence of external noise. Our layered model with a biologically suggested laminar structure describes the basic circuit mechanism underlying the attention-mode specific modulations of neuronal responses and visual perception. PMID:24324628

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks.

PubMed

Ruiz-Rizzo, Adriana L; Neitzel, Julia; Müller, Hermann J; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's "theory of visual attention" (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention parameters that are assumed to constitute relatively stable traits correspond distinctly to the functional connectivity both within and between particular functional networks. This implies that individual differences in basic attention functions are represented by differences in the coherence of slowly fluctuating brain activity.

Visual search and attention: an overview.

PubMed

Davis, Elizabeth T; Palmer, John

2004-01-01

This special feature issue is devoted to attention and visual search. Attention is a central topic in psychology and visual search is both a versatile paradigm for the study of visual attention and a topic of study in itself. Visual search depends on sensory, perceptual, and cognitive processes. As a result, the search paradigm has been used to investigate a diverse range of phenomena. Manipulating the search task can vary the demands on attention. In turn, attention modulates visual search by selecting and limiting the information available at various levels of processing. Focusing on the intersection of attention and search provides a relatively structured window into the wide world of attentional phenomena. In particular, the effects of divided attention are illustrated by the effects of set size (the number of stimuli in a display) and the effects of selective attention are illustrated by cueing subsets of stimuli within the display. These two phenomena provide the starting point for the articles in this special issue. The articles are organized into four general topics to help structure the issues of attention and search.

RADIANCE: a randomized controlled study of ranibizumab in patients with choroidal neovascularization secondary to pathologic myopia.

PubMed

Wolf, Sebastian; Balciuniene, Vilma Jurate; Laganovska, Guna; Menchini, Ugo; Ohno-Matsui, Kyoko; Sharma, Tarun; Wong, Tien Y; Silva, Rufino; Pilz, Stefan; Gekkieva, Margarita

2014-03-01

To compare the efficacy and safety of ranibizumab 0.5 mg, guided by visual acuity (VA) stabilization or disease activity criteria, versus verteporfin photodynamic therapy (vPDT) in patients with visual impairment due to myopic choroidal neovascularization (CNV). Phase III, 12-month, randomized, double-masked, multicenter, active-controlled study. Patients (N = 277) with visual impairment due to myopic CNV. Patients were randomized to receive ranibizumab on day 1, month 1, and thereafter as needed guided by VA stabilization criteria (group I, n = 106); ranibizumab on day 1 and thereafter as needed guided by disease activity criteria (group II, n=116); or vPDT on day 1 and disease activity treated with ranibizumab or vPDT at investigators' discretion from month 3 (group III, n = 55). Mean average best-corrected visual acuity (BCVA) change from baseline to month 1 through months 3 (primary) and 6, mean BCVA change and safety over 12 months. Ranibizumab treatment in groups I and II was superior to vPDT based on mean average BCVA change from baseline to month 1 through month 3 (group I: +10.5, group II: +10.6 vs. group III: +2.2 Early Treatment Diabetic Retinopathy Study [ETDRS] letters; both P<0.0001). Ranibizumab treatment guided by disease activity was noninferior to VA stabilization-guided retreatment based on mean average BCVA change from baseline to month 1 through month 6 (group II: +11.7 vs. group I: +11.9 ETDRS letters; P<0.00001). Mean BCVA change from baseline to month 12 was +13.8 (group I), +14.4 (group II), and +9.3 ETDRS letters (group III). At month 12, 63.8% to 65.7% of patients showed resolution of myopic CNV leakage. Patients received a median of 4.0 (group I) and 2.0 (groups II and III) ranibizumab injections over 12 months. No deaths or cases of endophthalmitis and myocardial infarction occurred. Ranibizumab treatment, irrespective of retreatment criteria, provided superior BCVA gains versus vPDT up to month 3. Ranibizumab treatment guided by disease activity criteria was noninferior to VA stabilization criteria up to month 6. Over 12 months, individualized ranibizumab treatment was effective in improving and sustaining BCVA and was generally well tolerated in patients with myopic CNV. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Amblyopia prevalence and risk factors in Australian preschool children.

PubMed

Pai, Amy Shih-I; Rose, Kathryn A; Leone, Jody F; Sharbini, Sharimawati; Burlutsky, George; Varma, Rohit; Wong, Tien Yin; Mitchell, Paul

2012-01-01

To determine the prevalence of and factors associated with amblyopia in a sample of Australian preschool children. Population-based, cross-sectional study. The Sydney Paediatric Eye Disease Study examined 2461 (73.8% participation) children aged between 6 and 72 months from 2007 to 2009. Visual acuity (VA) was assessed in children aged ≥ 30 months using the Electronic Visual Acuity system, and a subset using the logarithm of the minimum angle of resolution chart. Amblyopia was categorized into unilateral and bilateral subtypes: Unilateral amblyopia was defined as a 2-line difference in reduced VA between the 2 eyes, in addition to strabismus, anisometropia, and/or visual axis obstruction; bilateral amblyopia was defined as bilateral reduced VA with either bilateral visual axis obstruction or significant bilateral ametropia. Information on ethnicity, birth parameters, and measures of socioeconomic status were collected in questionnaires completed by parents. Amblyopia. We included 1422 children aged 30 to 72 months, of whom 27 (1.9%) were found to have amblyopia or suspected amblyopia. Mean spherical equivalent for the amblyopic eyes was +3.57 diopters, with a mean VA of 20/50. Only 3 of the 27 amblyopic children had previous diagnoses or treatments for amblyopia. In regression analysis controlling for age, gender, and ethnicity, amblyopia was significantly associated with hyperopia (odds ratio [OR], 15.3; 95% confidence interval [CI], 6.5-36.4), astigmatism (OR, 5.7; 95% CI, 2.5-12.7), anisometropia (OR, 27.8; 95% CI, 11.2-69.3), and strabismus (OR, 13.1; 95% CI, 4.3-40.4). There were no significant associations of amblyopia with low birthweight (<2500 g), preterm birth (<37 weeks), maternal smoking, age, gender, ethnicity, or measures of socioeconomic status (all P>0.05). Amblyopia was found in 1.9% of this Australian preschool sample, which is comparable with prevalence rates reported by other recent studies in preschool children. Refractive errors, particularly significant hyperopia and astigmatism, in addition to anisometropia and strabismus, were the major amblyogenic factors. There was a low amblyopia detection rate in this preschool population, which suggests that different strategies are required to improve current vision screening strategies in preschoolers. The authors have no proprietary or commercial interest in any of the materials discussed in this article. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Object-Based Visual Attention in 8-Month-Old Infants: Evidence from an Eye-Tracking Study

ERIC Educational Resources Information Center

Bulf, Hermann; Valenza, Eloisa

2013-01-01

Visual attention is one of the infant's primary tools for gathering relevant information from the environment for further processing and learning. The space-based component of visual attention in infants has been widely investigated; however, the object-based component of visual attention has received scarce interest. This scarcity is…

Infant visual attention and object recognition.

PubMed

Reynolds, Greg D

2015-05-15

This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of the KiVa antibullying program on cyberbullying and cybervictimization frequency among Finnish youth.

PubMed

Williford, Anne; Elledge, L Christian; Boulton, Aaron J; DePaolis, Kathryn J; Little, Todd D; Salmivalli, Christina

2013-01-01

Cyberbullying among school-aged children has received increased attention in recent literature. However, no empirical evidence currently exists on whether existing school-based antibullying programs are effective in targeting the unique aspects of cyberbullying. To address this important gap, the present study investigates the unique effects of the KiVa Antibullying Program on the frequency of cyberbullying and cybervictimization among elementary and middle school youth. Using data from a group randomized controlled trial, multilevel ordinal regression analyses were used to examine differences in the frequencies of cyberbullying and cybervictimization between intervention (N = 9,914) and control students (N = 8,498). The effects of age and gender on frequencies of cyber behaviors were also assessed across conditions. Results revealed a significant intervention effect on the frequency of cybervictimization; KiVa students reported lower frequencies of cybervictimization at posttest than students in a control condition. The effect of condition on the perpetration of cyberbullying was moderated by age. When student age was below the sample mean, KiVa students reported lower frequencies of cyberbullying than students in the control condition. We also found evidence of classroom level variation in cyberbullying and cybervictimization, suggesting cyberbullying is in part a classroom-level phenomenon. KiVa appears to be an efficacious program to address cyber forms of bullying and victimization. We discuss several unique aspects of KiVa that may account for the significant intervention effects. Results suggest that KiVa is an intervention option for schools concerned with reducing cyberbullying behavior and its deleterious effects on children's adjustment.

Association Between Adherence to Glasses Wearing During Amblyopia Treatment and Improvement in Visual Acuity.

PubMed

Maconachie, Gail D E; Farooq, Shegufta; Bush, Glen; Kempton, Julie; Proudlock, Frank A; Gottlob, Irene

2016-12-01

Occlusion dose monitors have helped establish that better adherence to occlusion is associated with improved visual outcomes in patients undergoing amblyopia treatment. However, the role of adherence to glasses wearing is unknown. To establish the feasibility and reliability of objectively monitoring adherence to glasses wearing using age-based norms, establish the association between adherence to glasses wearing and improvement in visual acuity (VA) after optical treatment and occlusion therapy, and analyze the effect of age, sex, refractive errors, type of amblyopia, and adherence to glasses wearing on improvement in VA. A prospective, observational, nonmasked, cohort study was conducted between June 8, 2008, and June 30, 2013, among patients at a pediatric ophthalmology clinic of a tertiary care hospital who were newly diagnosed with anisometropic and/or strabismic amblyopia and had not undergone previous treatment. The study consisted of a glasses phase (18 weeks) and a patching phase (glasses and occlusion for 10 hours per day for 12 weeks). Reliability of the glasses monitors was assessed by comparing diary entries and monitor recordings in adults. Objective monitoring of glasses wearing and occlusion. Adherence to glasses wearing (hours per day) and effect on VA. Among 20 children with anisometropia (mean [SD] age, 6.20 [2.16] years; 11 boys and 9 girls) and 20 with strabismic or mixed amblyopia (mean [SD] age, 4.90 [1.36] years; 10 boys and 10 girls), adherence to glasses wearing was successfully monitored in all but 1 patient. Agreement between diaries and monitored times wearing glasses in adults was high (intraclass correlation coefficient, 1.00; 95% CI, 0.999-1.00). Median (SD) adherence to glasses wearing was 70% (25.3%). A moderate correlation was observed between adherence to glasses wearing and percentage improvement in VA during the glasses phase (r = 0.462; P = .003). Multiple regression revealed that age (β = -0.535; P = .001), type of amblyopia (β = -0.347; P = .02), and adherence to glasses wearing (β = 0.287; P = .04) were independently associated with improvement in VA after the glasses phase and explained 42% of the variability (F3,35 = 8.457; P < .001). A strong correlation between glasses wearing and occlusion adherence was observed (r = 0.719; P < .001). The results suggest that adherence to glasses wearing is less than optimal and highly variable but is important in achieving good VA. This study emphasizes the importance of encouraging children to not only have good adherence to occlusion therapy but also to glasses wearing.

Spatial Scaling of the Profile of Selective Attention in the Visual Field.

PubMed

Gannon, Matthew A; Knapp, Ashley A; Adams, Thomas G; Long, Stephanie M; Parks, Nathan A

2016-01-01

Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs) to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load) and visual angle (1.0° or 2.5°). Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

Advanced control architecture for autonomous vehicles

NASA Astrophysics Data System (ADS)

Maurer, Markus; Dickmanns, Ernst D.

1997-06-01

An advanced control architecture for autonomous vehicles is presented. The hierarchical architecture consists of four levels: a vehicle level, a control level, a rule-based level and a knowledge-based level. A special focus is on forms of internal representation, which have to be chosen adequately for each level. The control scheme is applied to VaMP, a Mercedes passenger car which autonomously performs missions on German freeways. VaMP perceives the environment with its sense of vision and conventional sensors. It controls its actuators for locomotion and attention focusing. Modules for perception, cognition and action are discussed.

The role of early visual cortex in visual short-term memory and visual attention.

PubMed

Offen, Shani; Schluppeck, Denis; Heeger, David J

2009-06-01

We measured cortical activity with functional magnetic resonance imaging to probe the involvement of early visual cortex in visual short-term memory and visual attention. In four experimental tasks, human subjects viewed two visual stimuli separated by a variable delay period. The tasks placed differential demands on short-term memory and attention, but the stimuli were visually identical until after the delay period. Early visual cortex exhibited sustained responses throughout the delay when subjects performed attention-demanding tasks, but delay-period activity was not distinguishable from zero when subjects performed a task that required short-term memory. This dissociation reveals different computational mechanisms underlying the two processes.

Characterizing the effects of feature salience and top-down attention in the early visual system.

PubMed

Poltoratski, Sonia; Ling, Sam; McCormack, Devin; Tong, Frank

2017-07-01

The visual system employs a sophisticated balance of attentional mechanisms: salient stimuli are prioritized for visual processing, yet observers can also ignore such stimuli when their goals require directing attention elsewhere. A powerful determinant of visual salience is local feature contrast: if a local region differs from its immediate surround along one or more feature dimensions, it will appear more salient. We used high-resolution functional MRI (fMRI) at 7T to characterize the modulatory effects of bottom-up salience and top-down voluntary attention within multiple sites along the early visual pathway, including visual areas V1-V4 and the lateral geniculate nucleus (LGN). Observers viewed arrays of spatially distributed gratings, where one of the gratings immediately to the left or right of fixation differed from all other items in orientation or motion direction, making it salient. To investigate the effects of directed attention, observers were cued to attend to the grating to the left or right of fixation, which was either salient or nonsalient. Results revealed reliable additive effects of top-down attention and stimulus-driven salience throughout visual areas V1-hV4. In comparison, the LGN exhibited significant attentional enhancement but was not reliably modulated by orientation- or motion-defined salience. Our findings indicate that top-down effects of spatial attention can influence visual processing at the earliest possible site along the visual pathway, including the LGN, whereas the processing of orientation- and motion-driven salience primarily involves feature-selective interactions that take place in early cortical visual areas. NEW & NOTEWORTHY While spatial attention allows for specific, goal-driven enhancement of stimuli, salient items outside of the current focus of attention must also be prioritized. We used 7T fMRI to compare salience and spatial attentional enhancement along the early visual hierarchy. We report additive effects of attention and bottom-up salience in early visual areas, suggesting that salience enhancement is not contingent on the observer's attentional state. Copyright © 2017 the American Physiological Society.

Behavior Selection of Mobile Robot Based on Integration of Multimodal Information

NASA Astrophysics Data System (ADS)

Chen, Bin; Kaneko, Masahide

Recently, biologically inspired robots have been developed to acquire the capacity for directing visual attention to salient stimulus generated from the audiovisual environment. On purpose to realize this behavior, a general method is to calculate saliency maps to represent how much the external information attracts the robot's visual attention, where the audiovisual information and robot's motion status should be involved. In this paper, we represent a visual attention model where three modalities, that is, audio information, visual information and robot's motor status are considered, while the previous researches have not considered all of them. Firstly, we introduce a 2-D density map, on which the value denotes how much the robot pays attention to each spatial location. Then we model the attention density using a Bayesian network where the robot's motion statuses are involved. Secondly, the information from both of audio and visual modalities is integrated with the attention density map in integrate-fire neurons. The robot can direct its attention to the locations where the integrate-fire neurons are fired. Finally, the visual attention model is applied to make the robot select the visual information from the environment, and react to the content selected. Experimental results show that it is possible for robots to acquire the visual information related to their behaviors by using the attention model considering motion statuses. The robot can select its behaviors to adapt to the dynamic environment as well as to switch to another task according to the recognition results of visual attention.

Auditory Verbal Experience and Agency in Waking, Sleep Onset, REM, and Non-REM Sleep.

PubMed

Speth, Jana; Harley, Trevor A; Speth, Clemens

2017-04-01

We present one of the first quantitative studies on auditory verbal experiences ("hearing voices") and auditory verbal agency (inner speech, and specifically "talking to (imaginary) voices or characters") in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants' implicit knowledge of auditory verbal experiences (VE) and auditory verbal agencies (VA), displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement (REM) sleep, non-REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap sleep-wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. Copyright © 2016 Cognitive Science Society, Inc.

Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.

PubMed

Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

2017-12-01

Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.

Extracting alpha band modulation during visual spatial attention without flickering stimuli using common spatial pattern.

PubMed

Fujisawa, Junya; Touyama, Hideaki; Hirose, Michitaka

2008-01-01

In this paper, alpha band modulation during visual spatial attention without visual stimuli was focused. Visual spatial attention has been expected to provide a new channel of non-invasive independent brain computer interface (BCI), but little work has been done on the new interfacing method. The flickering stimuli used in previous work cause a decline of independency and have difficulties in a practical use. Therefore we investigated whether visual spatial attention could be detected without such stimuli. Further, the common spatial patterns (CSP) were for the first time applied to the brain states during visual spatial attention. The performance evaluation was based on three brain states of left, right and center direction attention. The 30-channel scalp electroencephalographic (EEG) signals over occipital cortex were recorded for five subjects. Without CSP, the analyses made 66.44 (range 55.42 to 72.27) % of average classification performance in discriminating left and right attention classes. With CSP, the averaged classification accuracy was 75.39 (range 63.75 to 86.13) %. It is suggested that CSP is useful in the context of visual spatial attention, and the alpha band modulation during visual spatial attention without flickering stimuli has the possibility of a new channel for independent BCI as well as motor imagery.

Attention Increases Spike Count Correlations between Visual Cortical Areas.

PubMed

Ruff, Douglas A; Cohen, Marlene R

2016-07-13

Visual attention, which improves perception of attended locations or objects, has long been known to affect many aspects of the responses of neuronal populations in visual cortex. There are two nonmutually exclusive hypotheses concerning the neuronal mechanisms that underlie these perceptual improvements. The first hypothesis, that attention improves the information encoded by a population of neurons in a particular cortical area, has considerable physiological support. The second hypothesis is that attention improves perception by selectively communicating relevant visual information. This idea has been tested primarily by measuring interactions between neurons on very short timescales, which are mathematically nearly independent of neuronal interactions on longer timescales. We tested the hypothesis that attention changes the way visual information is communicated between cortical areas on longer timescales by recording simultaneously from neurons in primary visual cortex (V1) and the middle temporal area (MT) in rhesus monkeys. We used two independent and complementary approaches. Our correlative experiment showed that attention increases the trial-to-trial response variability that is shared between the two areas. In our causal experiment, we electrically microstimulated V1 and found that attention increased the effect of stimulation on MT responses. Together, our results suggest that attention affects both the way visual stimuli are encoded within a cortical area and the extent to which visual information is communicated between areas on behaviorally relevant timescales. Visual attention dramatically improves the perception of attended stimuli. Attention has long been thought to act by selecting relevant visual information for further processing. It has been hypothesized that this selection is accomplished by increasing communication between neurons that encode attended information in different cortical areas. We recorded simultaneously from neurons in primary visual cortex and the middle temporal area while rhesus monkeys performed an attention task. We found that attention increased shared variability between neurons in the two areas and that attention increased the effect of microstimulation in V1 on the firing rates of MT neurons. Our results provide support for the hypothesis that attention increases communication between neurons in different brain areas on behaviorally relevant timescales. Copyright © 2016 the authors 0270-6474/16/367523-12$15.00/0.

Attention Increases Spike Count Correlations between Visual Cortical Areas

PubMed Central

Cohen, Marlene R.

2016-01-01

Visual attention, which improves perception of attended locations or objects, has long been known to affect many aspects of the responses of neuronal populations in visual cortex. There are two nonmutually exclusive hypotheses concerning the neuronal mechanisms that underlie these perceptual improvements. The first hypothesis, that attention improves the information encoded by a population of neurons in a particular cortical area, has considerable physiological support. The second hypothesis is that attention improves perception by selectively communicating relevant visual information. This idea has been tested primarily by measuring interactions between neurons on very short timescales, which are mathematically nearly independent of neuronal interactions on longer timescales. We tested the hypothesis that attention changes the way visual information is communicated between cortical areas on longer timescales by recording simultaneously from neurons in primary visual cortex (V1) and the middle temporal area (MT) in rhesus monkeys. We used two independent and complementary approaches. Our correlative experiment showed that attention increases the trial-to-trial response variability that is shared between the two areas. In our causal experiment, we electrically microstimulated V1 and found that attention increased the effect of stimulation on MT responses. Together, our results suggest that attention affects both the way visual stimuli are encoded within a cortical area and the extent to which visual information is communicated between areas on behaviorally relevant timescales. SIGNIFICANCE STATEMENT Visual attention dramatically improves the perception of attended stimuli. Attention has long been thought to act by selecting relevant visual information for further processing. It has been hypothesized that this selection is accomplished by increasing communication between neurons that encode attended information in different cortical areas. We recorded simultaneously from neurons in primary visual cortex and the middle temporal area while rhesus monkeys performed an attention task. We found that attention increased shared variability between neurons in the two areas and that attention increased the effect of microstimulation in V1 on the firing rates of MT neurons. Our results provide support for the hypothesis that attention increases communication between neurons in different brain areas on behaviorally relevant timescales. PMID:27413161

Attraction of position preference by spatial attention throughout human visual cortex.

PubMed

Klein, Barrie P; Harvey, Ben M; Dumoulin, Serge O

2014-10-01

Voluntary spatial attention concentrates neural resources at the attended location. Here, we examined the effects of spatial attention on spatial position selectivity in humans. We measured population receptive fields (pRFs) using high-field functional MRI (fMRI) (7T) while subjects performed an attention-demanding task at different locations. We show that spatial attention attracts pRF preferred positions across the entire visual field, not just at the attended location. This global change in pRF preferred positions systematically increases up the visual hierarchy. We model these pRF preferred position changes as an interaction between two components: an attention field and a pRF without the influence of attention. This computational model suggests that increasing effects of attention up the hierarchy result primarily from differences in pRF size and that the attention field is similar across the visual hierarchy. A similar attention field suggests that spatial attention transforms different neural response selectivities throughout the visual hierarchy in a similar manner. Copyright © 2014 Elsevier Inc. All rights reserved.

Submacular hemorrhage in neovascular age-related macular degeneration: A synthesis of the literature.

PubMed

Stanescu-Segall, Dinu; Balta, Florian; Jackson, Timothy L

2016-01-01

Large submacular hemorrhage, an uncommon manifestation of neovascular age-related macular degeneration, may also occur with idiopathic polypoidal choroidal vasculopathy. Submacular hemorrhage damages photoreceptors owing to iron toxicity, fibrin meshwork contraction, and reduced nutrient flux, with subsequent macular scarring. Clinical and experimental studies support prompt treatment, as tissue damage can occur within 24 hours. Without treatment the natural history is poor, with a mean final visual acuity (VA) of 20/1600. Reported treatments include retinal pigment epithelial patch, macular translocation, pneumatic displacement, intravitreal or subretinal tissue plasminogen activator, intravitreal anti-vascular endothelial growth factor (VEGF) drugs, and combinations thereof. In the absence of comparative studies, we combined eligible studies to assess the VA change before and after each treatment option. The greatest improvement occurred after combined pars plana vitrectomy, subretinal tissue plasminogen activator, intravitreal gas, and anti-vascular endothelial growth factor treatment, with VA improving from 20/1000 to 20/400. The best final VA occurred using combined intravitreal tissue plasminogen activator, gas, and anti-vascular endothelial growth factor therapy, with VA improving from 20/200 to 20/100. Both treatments had an acceptable safety profile, but most studies were small, and larger randomized controlled trials are needed to determine both safety and efficacy. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Perceptual organization and visual attention.

PubMed

Kimchi, Ruth

2009-01-01

Perceptual organization--the processes structuring visual information into coherent units--and visual attention--the processes by which some visual information in a scene is selected--are crucial for the perception of our visual environment and to visuomotor behavior. Recent research points to important relations between attentional and organizational processes. Several studies demonstrated that perceptual organization constrains attentional selectivity, and other studies suggest that attention can also constrain perceptual organization. In this chapter I focus on two aspects of the relationship between perceptual organization and attention. The first addresses the question of whether or not perceptual organization can take place without attention. I present findings demonstrating that some forms of grouping and figure-ground segmentation can occur without attention, whereas others require controlled attentional processing, depending on the processes involved and the conditions prevailing for each process. These findings challenge the traditional view, which assumes that perceptual organization is a unitary entity that operates preattentively. The second issue addresses the question of whether perceptual organization can affect the automatic deployment of attention. I present findings showing that the mere organization of some elements in the visual field by Gestalt factors into a coherent perceptual unit (an "object"), with no abrupt onset or any other unique transient, can capture attention automatically in a stimulus-driven manner. Taken together, the findings discussed in this chapter demonstrate the multifaceted, interactive relations between perceptual organization and visual attention.

Distinctive Correspondence Between Separable Visual Attention Functions and Intrinsic Brain Networks

PubMed Central

Ruiz-Rizzo, Adriana L.; Neitzel, Julia; Müller, Hermann J.; Sorg, Christian; Finke, Kathrin

2018-01-01

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention parameters that are assumed to constitute relatively stable traits correspond distinctly to the functional connectivity both within and between particular functional networks. This implies that individual differences in basic attention functions are represented by differences in the coherence of slowly fluctuating brain activity. PMID:29662444

Robotic Attention Processing And Its Application To Visual Guidance

NASA Astrophysics Data System (ADS)

Barth, Matthew; Inoue, Hirochika

1988-03-01

This paper describes a method of real-time visual attention processing for robots performing visual guidance. This robot attention processing is based on a novel vision processor, the multi-window vision system that was developed at the University of Tokyo. The multi-window vision system is unique in that it only processes visual information inside local area windows. These local area windows are quite flexible in their ability to move anywhere on the visual screen, change their size and shape, and alter their pixel sampling rate. By using these windows for specific attention tasks, it is possible to perform high speed attention processing. The primary attention skills of detecting motion, tracking an object, and interpreting an image are all performed at high speed on the multi-window vision system. A basic robotic attention scheme using the attention skills was developed. The attention skills involved detection and tracking of salient visual features. The tracking and motion information thus obtained was utilized in producing the response to the visual stimulus. The response of the attention scheme was quick enough to be applicable to the real-time vision processing tasks of playing a video 'pong' game, and later using an automobile driving simulator. By detecting the motion of a 'ball' on a video screen and then tracking the movement, the attention scheme was able to control a 'paddle' in order to keep the ball in play. The response was faster than that of a human's, allowing the attention scheme to play the video game at higher speeds. Further, in the application to the driving simulator, the attention scheme was able to control both direction and velocity of a simulated vehicle following a lead car. These two applications show the potential of local visual processing in its use for robotic attention processing.

Occipitoparietal alpha-band responses to the graded allocation of top-down spatial attention.

PubMed

Dombrowe, Isabel; Hilgetag, Claus C

2014-09-15

The voluntary, top-down allocation of visual spatial attention has been linked to changes in the alpha-band of the electroencephalogram (EEG) signal measured over occipital and parietal lobes. In the present study, we investigated how occipitoparietal alpha-band activity changes when people allocate their attentional resources in a graded fashion across the visual field. We asked participants to either completely shift their attention into one hemifield, to balance their attention equally across the entire visual field, or to attribute more attention to one-half of the visual field than to the other. As expected, we found that alpha-band amplitudes decreased stronger contralaterally than ipsilaterally to the attended side when attention was shifted completely. Alpha-band amplitudes decreased bilaterally when attention was balanced equally across the visual field. However, when participants allocated more attentional resources to one-half of the visual field, this was not reflected in the alpha-band amplitudes, which just decreased bilaterally. We found that the performance of the participants was more strongly reflected in the coherence between frontal and occipitoparietal brain regions. We conclude that low alpha-band amplitudes seem to be necessary for stimulus detection. Furthermore, complete shifts of attention are directly reflected in the lateralization of alpha-band amplitudes. In the present study, a gradual allocation of visual attention across the visual field was only indirectly reflected in the alpha-band activity over occipital and parietal cortexes. Copyright © 2014 the American Physiological Society.

Neural Mechanisms of Selective Visual Attention.

PubMed

Moore, Tirin; Zirnsak, Marc

2017-01-03

Selective visual attention describes the tendency of visual processing to be confined largely to stimuli that are relevant to behavior. It is among the most fundamental of cognitive functions, particularly in humans and other primates for whom vision is the dominant sense. We review recent progress in identifying the neural mechanisms of selective visual attention. We discuss evidence from studies of different varieties of selective attention and examine how these varieties alter the processing of stimuli by neurons within the visual system, current knowledge of their causal basis, and methods for assessing attentional dysfunctions. In addition, we identify some key questions that remain in identifying the neural mechanisms that give rise to the selective processing of visual information.

Natural History of the Central Structural Abnormalities in Choroideremia: A Prospective Cross-Sectional Study.

PubMed

Aleman, Tomas S; Han, Grace; Serrano, Leona W; Fuerst, Nicole M; Charlson, Emily S; Pearson, Denise J; Chung, Daniel C; Traband, Anastasia; Pan, Wei; Ying, Gui-Shuang; Bennett, Jean; Maguire, Albert M; Morgan, Jessica I W

2017-03-01

To describe in detail the central retinal structure of a large group of patients with choroideremia (CHM). A prospective, cross-sectional, descriptive study. Patients (n = 97, age 6-71 years) with CHM and subjects with normal vision (n = 44; ages 10-50 years) were included. Subjects were examined with spectral-domain optical coherence tomography (SD OCT) and near-infrared reflectance imaging. Visual acuity (VA) was measured during their encounter or obtained from recent ophthalmic examinations. Visual thresholds were measured in a subset of patients (n = 24) with automated static perimetry within the central regions (±15°) examined with SD OCT. Visual acuity and visual thresholds; total nuclear layer, inner nuclear layer (INL), and outer nuclear layer (ONL) thicknesses; and horizontal extent of the ONL and the photoreceptor outer segment (POS) interdigitation zone (IZ). Earliest abnormalities in regions with normally appearing retinal pigment epithelium (RPE) were the loss of the POS and ellipsoid zone associated with rod dysfunction. Transition zones (TZs) from relatively preserved retina to severe ONL thinning and inner retinal thickening moved centripetally with age. Most patients (88%) retained VAs better than 20/40 until their fifth decade of life. The VA decline coincided with migration of the TZ near the foveal center. There were outer retinal tubulations in degenerated, nonatrophic retina in the majority (69%) of patients. In general, RPE abnormalities paralleled photoreceptor degeneration, although there were regions with detectable but abnormally thin ONL co-localizing with severe RPE depigmentation and choroidal thinning. Abnormalities of the POS and rod dysfunction are the earliest central abnormalities observed in CHM. Foveal function is relatively preserved until the fifth decade of life. Migration of the TZs to the foveal center with foveal thinning and structural disorganization heralded central VA loss. The relationships established may help outline the eligibility criteria and outcome measures for clinical trials for CHM. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Reliability and validity of abbreviated surveys derived from the National Eye Institute Visual Function Questionnaire: The Study of Osteoporotic Fractures

PubMed Central

Gergana, Kodjebacheva; Coleman, Anne L.; Ensrud, Kristine E.; Cauley, Jane A.; Yu, Fei; Stone, Katie L.; Pedula, Kathryn L.; Hochberg, Marc C.; Mangione, Carol M.

2010-01-01

Purpose To test the reliability and validity of questionnaires shortened from the National Eye Institute 25-item Vision Function Questionnaire (NEI VFQ-9 and NEI VFQ-8). Design A cross-sectional multi-center cohort study. Methods Reliability was assessed by Cronbach alpha coefficients. Validity was evaluated by studying the association of vision-targeted quality-of-life composite scores with objective visual function measurements. Study population: A total of 5,482 women between the ages of 65 and 100 years participated in the Year-10 clinic visit in the Study of Osteoporotic Fractures (SOF). A total of 3,631 women with complete data were included in the visual acuity (VA) and visual field (VF) analysis of the NEI VFQ-9, which is defined for those who care to drive. and 5,311 in the analysis of the NEI VFQ-8. To assess differences in prevalent eye diseases, which were ascertained for a random sample of SOF participants, 853 and 1,237 women were included in the NEI VFQ-9 and the NEI VFQ-8 analyses, respectively. Results Cronbach alpha coefficient for the NEI VFQ-9 scale was 0.83 and that of the NEI VFQ-8 was 0.84. Using both questionnaires, women with VA worse than 20/40 had lower composite scores compared to those with VA 20/40 or better (p<0.001). Participants with mild, moderate, and severe binocular VF loss had lower composite scores compared to those with no binocular VF loss (p<0.001).Compared to women without chronic eye diseases in both eyes, women with at least one chronic eye disease in at least one eye had lower composite scores. Conclusions Both questionnaires showed high reliability across items and validity with respect to clinical markers of eye disease Future research should compare the properties of these shortened surveys to those of the NEI VFQ-25. PMID:20103058

Modulation of auditory spatial attention by visual emotional cues: differential effects of attentional engagement and disengagement for pleasant and unpleasant cues.

PubMed

Harrison, Neil R; Woodhouse, Rob

2016-05-01

Previous research has demonstrated that threatening, compared to neutral pictures, can bias attention towards non-emotional auditory targets. Here we investigated which subcomponents of attention contributed to the influence of emotional visual stimuli on auditory spatial attention. Participants indicated the location of an auditory target, after brief (250 ms) presentation of a spatially non-predictive peripheral visual cue. Responses to targets were faster at the location of the preceding visual cue, compared to at the opposite location (cue validity effect). The cue validity effect was larger for targets following pleasant and unpleasant cues compared to neutral cues, for right-sided targets. For unpleasant cues, the crossmodal cue validity effect was driven by delayed attentional disengagement, and for pleasant cues, it was driven by enhanced engagement. We conclude that both pleasant and unpleasant visual cues influence the distribution of attention across modalities and that the associated attentional mechanisms depend on the valence of the visual cue.

Visual Field Asymmetries in Attention Vary with Self-Reported Attention Deficits

ERIC Educational Resources Information Center

Poynter, William; Ingram, Paul; Minor, Scott

2010-01-01

The purpose of this study was to determine whether an index of self-reported attention deficits predicts the pattern of visual field asymmetries observed in behavioral measures of attention. Studies of "normal" subjects do not present a consistent pattern of asymmetry in attention functions, with some studies showing better left visual field (LVF)…

[Attention characteristics of children with different clinical subtypes of attention deficit hyperactivity disorder].

PubMed

Liu, Wen-Long; Zhao, Xu; Tan, Jian-Hui; Wang, Juan

2014-09-01

To explore the attention characteristics of children with different clinical subtypes of attention deficit hyperactivity disorder (ADHD) and to provide a basis for clinical intervention. A total of 345 children diagnosed with ADHD were selected and the subtypes were identified. Attention assessment was performed by the intermediate visual and auditory continuous performance test at diagnosis, and the visual and auditory attention characteristics were compared between children with different subtypes. A total of 122 normal children were recruited in the control group and their attention characteristics were compared with those of children with ADHD. The scores of full scale attention quotient (AQ) and full scale response control quotient (RCQ) of children with all three subtypes of ADHD were significantly lower than those of normal children (P<0.01). The score of auditory RCQ was significantly lower than that of visual RCQ in children with ADHD-hyperactive/impulsive subtype (P<0.05). The scores of auditory AQ and speed quotient (SQ) were significantly higher than those of visual AQ and SQ in three subtypes of ADHD children (P<0.01), while the score of visual precaution quotient (PQ) was significantly higher than that of auditory PQ (P<0.01). No significant differences in auditory or visual AQ were observed between the three subtypes of ADHD. The attention function of children with ADHD is worse than that of normal children, and the impairment of visual attention function is severer than that of auditory attention function. The degree of functional impairment of visual or auditory attention shows no significant differences between three subtypes of ADHD.

Attention and Visual Motor Integration in Young Children with Uncorrected Hyperopia.

PubMed

Kulp, Marjean Taylor; Ciner, Elise; Maguire, Maureen; Pistilli, Maxwell; Candy, T Rowan; Ying, Gui-Shuang; Quinn, Graham; Cyert, Lynn; Moore, Bruce

2017-10-01

Among 4- and 5-year-old children, deficits in measures of attention, visual-motor integration (VMI) and visual perception (VP) are associated with moderate, uncorrected hyperopia (3 to 6 diopters [D]) accompanied by reduced near visual function (near visual acuity worse than 20/40 or stereoacuity worse than 240 seconds of arc). To compare attention, visual motor, and visual perceptual skills in uncorrected hyperopes and emmetropes attending preschool or kindergarten and evaluate their associations with visual function. Participants were 4 and 5 years of age with either hyperopia (≥3 to ≤6 D, astigmatism ≤1.5 D, anisometropia ≤1 D) or emmetropia (hyperopia ≤1 D; astigmatism, anisometropia, and myopia each <1 D), without amblyopia or strabismus. Examiners masked to refractive status administered tests of attention (sustained, receptive, and expressive), VMI, and VP. Binocular visual acuity, stereoacuity, and accommodative accuracy were also assessed at near. Analyses were adjusted for age, sex, race/ethnicity, and parent's/caregiver's education. Two hundred forty-four hyperopes (mean, +3.8 ± [SD] 0.8 D) and 248 emmetropes (+0.5 ± 0.5 D) completed testing. Mean sustained attention score was worse in hyperopes compared with emmetropes (mean difference, -4.1; P < .001 for 3 to 6 D). Mean Receptive Attention score was worse in 4 to 6 D hyperopes compared with emmetropes (by -2.6, P = .01). Hyperopes with reduced near visual acuity (20/40 or worse) had worse scores than emmetropes (-6.4, P < .001 for sustained attention; -3.0, P = .004 for Receptive Attention; -0.7, P = .006 for VMI; -1.3, P = .008 for VP). Hyperopes with stereoacuity of 240 seconds of arc or worse scored significantly worse than emmetropes (-6.7, P < .001 for sustained attention; -3.4, P = .03 for Expressive Attention; -2.2, P = .03 for Receptive Attention; -0.7, P = .01 for VMI; -1.7, P < .001 for VP). Overall, hyperopes with better near visual function generally performed similarly to emmetropes. Moderately hyperopic children were found to have deficits in measures of attention. Hyperopic children with reduced near visual function also had lower scores on VMI and VP than emmetropic children.

Auditory and visual capture during focused visual attention.

PubMed

Koelewijn, Thomas; Bronkhorst, Adelbert; Theeuwes, Jan

2009-10-01

It is well known that auditory and visual onsets presented at a particular location can capture a person's visual attention. However, the question of whether such attentional capture disappears when attention is focused endogenously beforehand has not yet been answered. Moreover, previous studies have not differentiated between capture by onsets presented at a nontarget (invalid) location and possible performance benefits occurring when the target location is (validly) cued. In this study, the authors modulated the degree of attentional focus by presenting endogenous cues with varying reliability and by displaying placeholders indicating the precise areas where the target stimuli could occur. By using not only valid and invalid exogenous cues but also neutral cues that provide temporal but no spatial information, they found performance benefits as well as costs when attention is not strongly focused. The benefits disappear when the attentional focus is increased. These results indicate that there is bottom-up capture of visual attention by irrelevant auditory and visual stimuli that cannot be suppressed by top-down attentional control. PsycINFO Database Record (c) 2009 APA, all rights reserved.

Lokomat training in vascular dementia: motor improvement and beyond!

PubMed

Calabrò, Rocco Salvatore; De Luca, Rosaria; Leo, Antonino; Balletta, Tina; Marra, Angela; Bramanti, Placido

2015-12-01

Vascular dementia (VaD) is a general term describing problems with reasoning, planning, judgment, memory, and other thought processes caused by brain damage from impaired blood flow to the brain. Cognitive rehabilitation and physical therapy are the mainstays of dementia treatment, although often ineffective because of the scarce collaboration of the patients. However, emerging data suggest that physical activity may reduce the risk of cognitive impairment, mainly VaD, in older people living independently. Herein, we describe a 72-year-old male affected by VaD, in which traditional cognitive training in addition to intensive gait robotic rehabilitation (by using Lokomat device) led to a significant improvement in the motor and cognitive function. This promising finding may be related either to the intensive and repetitive aerobic exercises or to the task-oriented training with computerized visual feedback, which can be considered as a relevant tool to increase patients' motor output, involvement, and motivation during robotic training.

Role of macular hole angle in macular hole closure.

PubMed

Chhablani, Jay; Khodani, Mitali; Hussein, Abdullah; Bondalapati, Sailaja; Rao, Harsha B; Narayanan, Raja; Sudhalkar, Aditya

2015-12-01

To evaluate correlation of various spectral-domain optical coherence tomography (SD-OCT) parameters including macular hole angle as well as various indices with anatomical and visual outcomes after idiopathic macular hole repair surgery. Retrospective study of 137 eyes of 137 patients who underwent idiopathic macular hole repair surgery between January 2008 and January 2014 was performed. Various qualitative parameters such as presence of vitreomacular traction, epiretinal membrane and cystic edges at the macular hole as well as quantitative parameters such as maximum diameter on the apex of the hole, minimum diameter between edges, nasal and temporal vertical height, longest base diameter and macular hole angle between the retinal edge and the retinal pigment epithelium were noted. Indices including hole form factor, Macular Hole Index (MHI), Diameter Hole Index and Tractional Hole Index (THI) were calculated. Univariate and multivariate regression analysis was performed separately for final visual acuity (VA) and type of closure as dependent variable in relation to SD-OCT parameters as independent variables. On multivariate regression only minimum diameter between edges (p≤0.01) and longest base diameter (p≤0.03) were correlated significantly with both, type 1 closure and final VA. Among the indices, significant correlation of MHI (p=0.009) was noted with type of closure and that of THI with final VA (p=0.017). Our study shows no significant correlation between macular hole angle and hole closure. Minimum diameter between the edges and longest diameter of the hole are best predictors of hole closure and postoperative VA. 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/

Toward the influence of temporal attention on the selection of targets in a visual search task: An ERP study.

PubMed

Rolke, Bettina; Festl, Freya; Seibold, Verena C

2016-11-01

We used ERPs to investigate whether temporal attention interacts with spatial attention and feature-based attention to enhance visual processing. We presented a visual search display containing one singleton stimulus among a set of homogenous distractors. Participants were asked to respond only to target singletons of a particular color and shape that were presented in an attended spatial position. We manipulated temporal attention by presenting a warning signal before each search display and varying the foreperiod (FP) between the warning signal and the search display in a blocked manner. We observed distinctive ERP effects of both spatial and temporal attention. The amplitudes for the N2pc, SPCN, and P3 were enhanced by spatial attention indicating a processing benefit of relevant stimulus features at the attended side. Temporal attention accelerated stimulus processing; this was indexed by an earlier onset of the N2pc component and a reduction in reaction times to targets. Most importantly, temporal attention did not interact with spatial attention or stimulus features to influence visual processing. Taken together, the results suggest that temporal attention fosters visual perceptual processing in a visual search task independently from spatial attention and feature-based attention; this provides support for the nonspecific enhancement hypothesis of temporal attention. © 2016 Society for Psychophysiological Research.

Spatial and object-based attention modulates broadband high-frequency responses across the human visual cortical hierarchy.

PubMed

Davidesco, Ido; Harel, Michal; Ramot, Michal; Kramer, Uri; Kipervasser, Svetlana; Andelman, Fani; Neufeld, Miri Y; Goelman, Gadi; Fried, Itzhak; Malach, Rafael

2013-01-16

One of the puzzling aspects in the visual attention literature is the discrepancy between electrophysiological and fMRI findings: whereas fMRI studies reveal strong attentional modulation in the earliest visual areas, single-unit and local field potential studies yielded mixed results. In addition, it is not clear to what extent spatial attention effects extend from early to high-order visual areas. Here we addressed these issues using electrocorticography recordings in epileptic patients. The patients performed a task that allowed simultaneous manipulation of both spatial and object-based attention. They were presented with composite stimuli, consisting of a small object (face or house) superimposed on a large one, and in separate blocks, were instructed to attend one of the objects. We found a consistent increase in broadband high-frequency (30-90 Hz) power, but not in visual evoked potentials, associated with spatial attention starting with V1/V2 and continuing throughout the visual hierarchy. The magnitude of the attentional modulation was correlated with the spatial selectivity of each electrode and its distance from the occipital pole. Interestingly, the latency of the attentional modulation showed a significant decrease along the visual hierarchy. In addition, electrodes placed over high-order visual areas (e.g., fusiform gyrus) showed both effects of spatial and object-based attention. Overall, our results help to reconcile previous observations of discrepancy between fMRI and electrophysiology. They also imply that spatial attention effects can be found both in early and high-order visual cortical areas, in parallel with their stimulus tuning properties.

Visual Attention and Applications in Multimedia Technologies

PubMed Central

Le Callet, Patrick; Niebur, Ernst

2013-01-01

Making technological advances in the field of human-machine interactions requires that the capabilities and limitations of the human perceptual system are taken into account. The focus of this report is an important mechanism of perception, visual selective attention, which is becoming more and more important for multimedia applications. We introduce the concept of visual attention and describe its underlying mechanisms. In particular, we introduce the concepts of overt and covert visual attention, and of bottom-up and top-down processing. Challenges related to modeling visual attention and their validation using ad hoc ground truth are also discussed. Examples of the usage of visual attention models in image and video processing are presented. We emphasize multimedia delivery, retargeting and quality assessment of image and video, medical imaging, and the field of stereoscopic 3D images applications. PMID:24489403

Degraded attentional modulation of cortical neural populations in strabismic amblyopia

PubMed Central

Hou, Chuan; Kim, Yee-Joon; Lai, Xin Jie; Verghese, Preeti

2016-01-01

Behavioral studies have reported reduced spatial attention in amblyopia, a developmental disorder of spatial vision. However, the neural populations in the visual cortex linked with these behavioral spatial attention deficits have not been identified. Here, we use functional MRI–informed electroencephalography source imaging to measure the effect of attention on neural population activity in the visual cortex of human adult strabismic amblyopes who were stereoblind. We show that compared with controls, the modulatory effects of selective visual attention on the input from the amblyopic eye are substantially reduced in the primary visual cortex (V1) as well as in extrastriate visual areas hV4 and hMT+. Degraded attentional modulation is also found in the normal-acuity fellow eye in areas hV4 and hMT+ but not in V1. These results provide electrophysiological evidence that abnormal binocular input during a developmental critical period may impact cortical connections between the visual cortex and higher level cortices beyond the known amblyopic losses in V1 and V2, suggesting that a deficit of attentional modulation in the visual cortex is an important component of the functional impairment in amblyopia. Furthermore, we find that degraded attentional modulation in V1 is correlated with the magnitude of interocular suppression and the depth of amblyopia. These results support the view that the visual suppression often seen in strabismic amblyopia might be a form of attentional neglect of the visual input to the amblyopic eye. PMID:26885628

Degraded attentional modulation of cortical neural populations in strabismic amblyopia.

PubMed

Hou, Chuan; Kim, Yee-Joon; Lai, Xin Jie; Verghese, Preeti

2016-01-01

Behavioral studies have reported reduced spatial attention in amblyopia, a developmental disorder of spatial vision. However, the neural populations in the visual cortex linked with these behavioral spatial attention deficits have not been identified. Here, we use functional MRI-informed electroencephalography source imaging to measure the effect of attention on neural population activity in the visual cortex of human adult strabismic amblyopes who were stereoblind. We show that compared with controls, the modulatory effects of selective visual attention on the input from the amblyopic eye are substantially reduced in the primary visual cortex (V1) as well as in extrastriate visual areas hV4 and hMT+. Degraded attentional modulation is also found in the normal-acuity fellow eye in areas hV4 and hMT+ but not in V1. These results provide electrophysiological evidence that abnormal binocular input during a developmental critical period may impact cortical connections between the visual cortex and higher level cortices beyond the known amblyopic losses in V1 and V2, suggesting that a deficit of attentional modulation in the visual cortex is an important component of the functional impairment in amblyopia. Furthermore, we find that degraded attentional modulation in V1 is correlated with the magnitude of interocular suppression and the depth of amblyopia. These results support the view that the visual suppression often seen in strabismic amblyopia might be a form of attentional neglect of the visual input to the amblyopic eye.

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment.

PubMed

Allen, Peter M; Latham, Keziah; Mann, David L; Ravensbergen, Rianne H J C; Myint, Joy

2016-01-01

The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual's average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving 'expected' or 'below expected' shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An impairment to CS could impact performance in the sport and might be considered in determining eligibility to take part in VI competition.

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment

PubMed Central

Allen, Peter M.; Latham, Keziah; Mann, David L.; Ravensbergen, Rianne H. J. C.; Myint, Joy

2016-01-01

The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual’s average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving ‘expected’ or ‘below expected’ shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An impairment to CS could impact performance in the sport and might be considered in determining eligibility to take part in VI competition. PMID:27877150

Measuring aniseikonia using scattering filters to simulate cataract

NASA Astrophysics Data System (ADS)

Wilson, Jason

2011-12-01

The relationship between anisometropia and aniseikonia (ANK) is not well understood. Ametropic cataract patients provide a unique opportunity to study this relationship after undergoing emmetropizing lens extraction. Because light scatter may affect ANK measurement in cataract patients, its effect should also be evaluated. The Basic Aniseikonia Test (BAT) was evaluated using afocal size lenses to produce specific changes in retinal height. Several light scattering devices were then evaluated to determine which produced effects most similar to cataract. Contrast sensitivity and visual acuity (VA) losses were measured with each device and compared to those reported in cataract. After determining the most appropriate light scattering device, twenty healthy patients with normal visual function were recruited to perform the BAT using the filters to simulate cataract. Cataract patients were recruited from Vision America and the University of Alabama at Birmingham School of Optometry. Patients between 20 and 75 years of age with at least 20/80 VA in each eye, ≥ 2D ametropia, and normal binocular function were recruited. Stereopsis and ANK were tested and each patient completed a symptom questionnaire. ANK measurements using afocal size lenses indicated that the BAT underestimates ANK, although the effect was minimal for vertical targets and darkened surroundings, as previously reported. Based on VA and contrast sensitivity loss, Vistech scattering filters produced changes most similar to cataract. Results of the BAT using Vistech filters demonstrated that a moderate cataract but not a mild cataract may affect the ANK measurement. ANK measurements on cataract patients indicated that those with ≥ 2 D ametropia in each eye may suffer from induced ANK after the first cataract extraction. With upcoming healthcare reform, unilateral cataract extraction may be covered, but not necessarily bilateral, depending on patient VA in each eye. However, a questionnaire about symptoms at each visit in the current study showed that visual comfort did not improve after unilateral, but did improve after bilateral, cataract extraction. This indicates that quality of life should be better in bilateral cataract patients only if both cataracts are removed. This is supported by the findings of other studies. Keywords: Aniseikonia, Anisometropia, Cataract, Ametropia

Prevalence and the risk factors for visual impairment in age-related macular degeneration.

PubMed

Srinivasan, S; Swaminathan, G; Kulothungan, V; Raman, R; Sharma, T

2017-06-01

PurposeTo characterize the type, and the causes of visual impairment (VI) in various stages of early and late age-related macular degeneration (AMD) and the factors associated with visual impairment in subjects with AMDMethods6617 subjects ≥60 years were enumerated; 5495 (83.04%) participated in eye examination. Of which, 4791 subjects had gradable fundus images. AMD was graded per International ARM Epidemiological Study Group. Subjects underwent detailed ophthalmic exam. VI was defined per the WHO classification. Mild VI was defined as VA less than 6/12 to 6/18, moderate VI-VA less than 6/18 but up to 6/60, severe VI-VA less than 6/60 but up to 3/60 and legal blindness-VA worse than 3/60. Factors associated with VI in AMD was analyzed with univariate and logistic regression analysis.ResultsNine hundred and eighty-eight subjects were identified as having AMD (893 with early AMD and 95 with late AMD); 85% of the subjects (95% CI: 82.7-87.1) had no VI, 13.1% had mild VI (95% CI: 11.1-15.3), 0.8% had severe VI (95% CI: 0.4-1.6), 1.1% had legal blindness (95% CI: 0.6-1.9). Prevalence of any VI was 13.7% in early AMD and 27.4% in late AMD, P=0.0004; age group 65-70 years (OR=1.89, 95% CI: 1.16-3.08, P=0.011), and those ≥75 years (OR=3.67, 95% CI: 1.95-6.91, P=0.0001) had greater odds of VI compared with age group 60-64 years. Male gender was a protective factor for VI (OR=0.57, CI: 0.36-0.90, P=0.016). Cataract (31.8%) and refractive error (28.4%) accounted for a majority of the VI.ConclusionsCataract and refractive error account for a significant proportion of VI in the south Indian population with AMD. Early AMD is the third leading cause of VI. Greater age and female gender are associated with VI in subjects with AMD.

Cross-modal cueing of attention alters appearance and early cortical processing of visual stimuli

PubMed Central

Störmer, Viola S.; McDonald, John J.; Hillyard, Steven A.

2009-01-01

The question of whether attention makes sensory impressions appear more intense has been a matter of debate for over a century. Recent psychophysical studies have reported that attention increases apparent contrast of visual stimuli, but the issue continues to be debated. We obtained converging neurophysiological evidence from human observers as they judged the relative contrast of visual stimuli presented to the left and right visual fields following a lateralized auditory cue. Cross-modal cueing of attention boosted the apparent contrast of the visual target in association with an enlarged neural response in the contralateral visual cortex that began within 100 ms after target onset. The magnitude of the enhanced neural response was positively correlated with perceptual reports of the cued target being higher in contrast. The results suggest that attention increases the perceived contrast of visual stimuli by boosting early sensory processing in the visual cortex. PMID:20007778

Cross-modal cueing of attention alters appearance and early cortical processing of visual stimuli.

PubMed

Störmer, Viola S; McDonald, John J; Hillyard, Steven A

2009-12-29

The question of whether attention makes sensory impressions appear more intense has been a matter of debate for over a century. Recent psychophysical studies have reported that attention increases apparent contrast of visual stimuli, but the issue continues to be debated. We obtained converging neurophysiological evidence from human observers as they judged the relative contrast of visual stimuli presented to the left and right visual fields following a lateralized auditory cue. Cross-modal cueing of attention boosted the apparent contrast of the visual target in association with an enlarged neural response in the contralateral visual cortex that began within 100 ms after target onset. The magnitude of the enhanced neural response was positively correlated with perceptual reports of the cued target being higher in contrast. The results suggest that attention increases the perceived contrast of visual stimuli by boosting early sensory processing in the visual cortex.

Attentional Processes in Young Children with Congenital Visual Impairment

ERIC Educational Resources Information Center

Tadic, Valerie; Pring, Linda; Dale, Naomi

2009-01-01

The study investigated attentional processes of 32 preschool children with congenital visual impairment (VI). Children with profound visual impairment (PVI) and severe visual impairment (SVI) were compared to a group of typically developing sighted children in their ability to respond to adult directed attention in terms of establishing,…

Visual Attention to Antismoking PSAs: Smoking Cues versus Other Attention-Grabbing Features

ERIC Educational Resources Information Center

Sanders-Jackson, Ashley N.; Cappella, Joseph N.; Linebarger, Deborah L.; Piotrowski, Jessica Taylor; O'Keeffe, Moira; Strasser, Andrew A.

2011-01-01

This study examines how addicted smokers attend visually to smoking-related public service announcements (PSAs) in adults smokers. Smokers' onscreen visual fixation is an indicator of cognitive resources allocated to visual attention. Characteristic of individuals with addictive tendencies, smokers are expected to be appetitively activated by…

Attention versus consciousness in the visual brain: differences in conception, phenomenology, behavior, neuroanatomy, and physiology.

PubMed

Baars, B J

1999-07-01

A common confound between consciousness and attention makes it difficult to think clearly about recent advances in the understanding of the visual brain. Visual consciousness involves phenomenal experience of the visual world, but visual attention is more plausibly treated as a function that selects and maintains the selection of potential conscious contents, often unconsciously. In the same sense, eye movements select conscious visual events, which are not the same as conscious visual experience. According to common sense, visual experience is consciousness, and selective processes are labeled as attention. The distinction is reflected in very different behavioral measures and in very different brain anatomy and physiology. Visual consciousness tends to be associated with the "what" stream of visual feature neurons in the ventral temporal lobe. In contrast, attentional selection and maintenance are mediated by other brain regions, ranging from superior colliculi to thalamus, prefrontal cortex, and anterior cingulate. The author applied the common-sense distinction between attention and consciousness to the theoretical positions of M. I. Posner (1992, 1994) and D. LaBerge (1997, 1998) to show how it helps to clarify the evidence. He concluded that clarity of thought is served by calling a thing by its proper name.

A Comparative Study on the Visual Perceptions of Children with Attention Deficit Hyperactivity Disorder

NASA Astrophysics Data System (ADS)

Ahmetoglu, Emine; Aral, Neriman; Butun Ayhan, Aynur

This study was conducted in order to (a) compare the visual perceptions of seven-year-old children diagnosed with attention deficit hyperactivity disorder with those of normally developing children of the same age and development level and (b) determine whether the visual perceptions of children with attention deficit hyperactivity disorder vary with respect to gender, having received preschool education and parents` educational level. A total of 60 children, 30 with attention deficit hyperactivity disorder and 30 with normal development, were assigned to the study. Data about children with attention deficit hyperactivity disorder and their families was collected by using a General Information Form and the visual perception of children was examined through the Frostig Developmental Test of Visual Perception. The Mann-Whitney U-test and Kruskal-Wallis variance analysis was used to determine whether there was a difference of between the visual perceptions of children with normal development and those diagnosed with attention deficit hyperactivity disorder and to discover whether the variables of gender, preschool education and parents` educational status affected the visual perceptions of children with attention deficit hyperactivity disorder. The results showed that there was a statistically meaningful difference between the visual perceptions of the two groups and that the visual perceptions of children with attention deficit hyperactivity disorder were affected meaningfully by gender, preschool education and parents` educational status.

Simultaneous selection by object-based attention in visual and frontal cortex

PubMed Central

Pooresmaeili, Arezoo; Poort, Jasper; Roelfsema, Pieter R.

2014-01-01

Models of visual attention hold that top-down signals from frontal cortex influence information processing in visual cortex. It is unknown whether situations exist in which visual cortex actively participates in attentional selection. To investigate this question, we simultaneously recorded neuronal activity in the frontal eye fields (FEF) and primary visual cortex (V1) during a curve-tracing task in which attention shifts are object-based. We found that accurate performance was associated with similar latencies of attentional selection in both areas and that the latency in both areas increased if the task was made more difficult. The amplitude of the attentional signals in V1 saturated early during a trial, whereas these selection signals kept increasing for a longer time in FEF, until the moment of an eye movement, as if FEF integrated attentional signals present in early visual cortex. In erroneous trials, we observed an interareal latency difference because FEF selected the wrong curve before V1 and imposed its erroneous decision onto visual cortex. The neuronal activity in visual and frontal cortices was correlated across trials, and this trial-to-trial coupling was strongest for the attended curve. These results imply that selective attention relies on reciprocal interactions within a large network of areas that includes V1 and FEF. PMID:24711379

The Effects of Visual Attention Span and Phonological Decoding in Reading Comprehension in Dyslexia: A Path Analysis.

PubMed

Chen, Chen; Schneps, Matthew H; Masyn, Katherine E; Thomson, Jennifer M

2016-11-01

Increasing evidence has shown visual attention span to be a factor, distinct from phonological skills, that explains single-word identification (pseudo-word/word reading) performance in dyslexia. Yet, little is known about how well visual attention span explains text comprehension. Observing reading comprehension in a sample of 105 high school students with dyslexia, we used a pathway analysis to examine the direct and indirect path between visual attention span and reading comprehension while controlling for other factors such as phonological awareness, letter identification, short-term memory, IQ and age. Integrating phonemic decoding efficiency skills in the analytic model, this study aimed to disentangle how visual attention span and phonological skills work together in reading comprehension for readers with dyslexia. We found visual attention span to have a significant direct effect on more difficult reading comprehension but not on an easier level. It also had a significant direct effect on pseudo-word identification but not on word identification. In addition, we found that visual attention span indirectly explains reading comprehension through pseudo-word reading and word reading skills. This study supports the hypothesis that at least part of the dyslexic profile can be explained by visual attention abilities. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The role of visual attention in multiple object tracking: evidence from ERPs.

PubMed

Doran, Matthew M; Hoffman, James E

2010-01-01

We examined the role of visual attention in the multiple object tracking (MOT) task by measuring the amplitude of the N1 component of the event-related potential (ERP) to probe flashes presented on targets, distractors, or empty background areas. We found evidence that visual attention enhances targets and suppresses distractors (Experiment 1 & 3). However, we also found that when tracking load was light (two targets and two distractors), accurate tracking could be carried out without any apparent contribution from the visual attention system (Experiment 2). Our results suggest that attentional selection during MOT is flexibly determined by task demands as well as tracking load and that visual attention may not always be necessary for accurate tracking.

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

Long-term Follow-up and Outcomes in Traumatic Macular Holes.

PubMed

Miller, John B; Yonekawa, Yoshihiro; Eliott, Dean; Kim, Ivana K; Kim, Leo A; Loewenstein, John I; Sobrin, Lucia; Young, Lucy H; Mukai, Shizuo; Vavvas, Demetrios G

2015-12-01

To review presenting characteristics, clinical course, and long-term visual and anatomic outcomes of patients with traumatic macular holes at a tertiary referral center. Retrospective case series. Twenty-eight consecutive patients with traumatic macular holes at a single tertiary referral center were reviewed. In addition to visual acuities and treatments throughout the clinical course, specific dimensions of the macular hole, including diameters, height, configuration, shape, and the presence of a cuff of fluid, were examined using spectral-domain optical coherence tomography (OCT). Twenty-eight patients were identified with a mean initial visual acuity (VA) of logMAR 1.3 (20/400) and a mean follow-up of 2.2 years. Eleven holes (39.3%) closed spontaneously in median 5.7 weeks. Eleven underwent vitrectomy with a median time to intervention of 35.1 weeks. Median time to surgery for the 5 eyes with successful hole closure was 11.0 weeks vs 56.3 weeks for the 6 eyes that failed to close (P = .02). VA improved in closed holes (P < .01), whether spontaneously (P < .01) or via vitrectomy (P = .04), but VA did not improve in holes that did not close (P = .22). There was no relation between initial OCT dimensions and final hole closure status, although there was a trend, which did not reach statistical significance, toward small dimensions for those that closed spontaneously. A fairly high spontaneous closure rate was observed, with a trend toward smaller OCT dimensions. We found no relationship between hole closure and the OCT characteristics of the hole. Surgical intervention was less successful at hole closure when elected after 3 months. Copyright © 2015 Elsevier Inc. All rights reserved.

Measuring visual outcomes in children with uveitis using the “Effects of Youngsters’ Eyesight on Quality of Life” questionnaire

PubMed Central

Angeles-Han, Sheila T.; Yeh, Steven; McCracken, Courtney; Jenkins, Kirsten; Stryker, Daneka; Myoung, Erica; Vogler, Larry; Rouster-Stevens, Kelly; Lambert, Scott R.; Harrison, Melanie J.; Prahalad, Sampath; Drews-Botsch, Carolyn

2015-01-01

Objective The Effects of Youngsters’ Eyesight on Quality of Life (EYE-Q) is a novel measure of vision-related quality of life (QOL) and function in children. We aim to determine the validity of EYE-Q in childhood uveitis. Methods We abstracted medical record data on arthritis and uveitis in a convenience sample of children with juvenile idiopathic arthritis (JIA) and/or uveitis. In addition to the EYE-Q, parents and patients completed questionnaires on overall QOL (Pediatric QOL Inventory - PedsQL), and physical functioning (Childhood Health Assessment Questionnaire - CHAQ). Results Among 57 children (8 JIA, 24 JIA and uveitis, 25 uveitis alone), 102 ocular examinations were performed within 1 month of completing questionnaires. Uveitis patients had bilateral disease (69%), anterior involvement (78%), synechiae (51%) and cataracts (49%). Children with vision loss in their better eye (visual acuity (VA) 20/50 or worse) had worse EYE-Q (p = 0.006), and PedsQL (p = 0.028), but not CHAQ scores. The EYE-Q moderately correlated with logMAR VA (rs = −0.43), PedsQL (rs = 0.43) and CHAQ (rs = −0.45), but was not correlated with anterior chamber cells or intraocular pressure. The PedsQL and CHAQ did not correlate with VA or cells. There were strong correlations between the parent and child EYE-Q (rs = 0.62). Cronbach's α for the child report was 0.91. The EYE-Q had strong test-retest reliability (rs=0.75). Conclusion The EYE-Q may be an important tool in the assessment of visual outcomes in childhood uveitis and an improvement over general measures in detecting changes in vision-related function. PMID:26037544

A 3-year prospective study on ocular injuries with tennis or cricket ball while playing cricket: A case series.

PubMed

Mahapatra, Santosh Kumar; Malhotra, Kundan; Mendke, Rohit Ganapatrao

2018-02-01

The purpose of this study is to study the clinical features, visual outcome, management, and ocular complications of ocular injury, following trauma with tennis or cricket ball. A prospective, noncomparative case study of patients having injury with tennis/cricket ball while playing cricket was conducted between January 2013 and April 2016. Seventy-six eyes of 76 patients were studied. Presenting vision, age, gender, time since injury, general and ocular examination, intraocular pressure, indirect ophthalmoscopy, B scan, and X-ray/computed tomography scan findings were noted. Patients were managed medically or surgically as per the need and followed up at least for 6 months. Seventy-six eyes of 76 patients were studied. All cases were male, except two. Majority (80.2%) were <25 years. Median presenting visual acuity (VA) was 6/36 and median final VA was 6/18. Significant findings in the decreasing order of frequency were sphincter tear (26.3%), retinal detachment (23.6%), angle recession (18.4%), choroidal rupture (17.1%), and Berlin's edema (15.7%). Most of the cases (69.7%) were managed medically. Only 30.2% cases needed surgical intervention. Final visual outcome in our study was depended on initial VA (P = 0.000). It was also correlating with presenting clinical feature (P = 0.010) and type of intervention (medical/surgical) (P = 0.001). Cricket-related ocular injury generally has a poor prognosis with most cases being closed globe injury; retinal detachment is the most common vision-threatening presentation. In spite of being a common event, cricket-related injury is sparingly documented and hence needs further studies for proper documentation, prognostication, and formulation of definitive management plan.

Social Image Captioning: Exploring Visual Attention and User Attention.

PubMed

Wang, Leiquan; Chu, Xiaoliang; Zhang, Weishan; Wei, Yiwei; Sun, Weichen; Wu, Chunlei

2018-02-22

Image captioning with a natural language has been an emerging trend. However, the social image, associated with a set of user-contributed tags, has been rarely investigated for a similar task. The user-contributed tags, which could reflect the user attention, have been neglected in conventional image captioning. Most existing image captioning models cannot be applied directly to social image captioning. In this work, a dual attention model is proposed for social image captioning by combining the visual attention and user attention simultaneously.Visual attention is used to compress a large mount of salient visual information, while user attention is applied to adjust the description of the social images with user-contributed tags. Experiments conducted on the Microsoft (MS) COCO dataset demonstrate the superiority of the proposed method of dual attention.

Social Image Captioning: Exploring Visual Attention and User Attention

PubMed Central

Chu, Xiaoliang; Zhang, Weishan; Wei, Yiwei; Sun, Weichen; Wu, Chunlei

2018-01-01

Image captioning with a natural language has been an emerging trend. However, the social image, associated with a set of user-contributed tags, has been rarely investigated for a similar task. The user-contributed tags, which could reflect the user attention, have been neglected in conventional image captioning. Most existing image captioning models cannot be applied directly to social image captioning. In this work, a dual attention model is proposed for social image captioning by combining the visual attention and user attention simultaneously.Visual attention is used to compress a large mount of salient visual information, while user attention is applied to adjust the description of the social images with user-contributed tags. Experiments conducted on the Microsoft (MS) COCO dataset demonstrate the superiority of the proposed method of dual attention. PMID:29470409

The involvement of central attention in visual search is determined by task demands.

PubMed

Han, Suk Won

2017-04-01

Attention, the mechanism by which a subset of sensory inputs is prioritized over others, operates at multiple processing stages. Specifically, attention enhances weak sensory signal at the perceptual stage, while it serves to select appropriate responses or consolidate sensory representations into short-term memory at the central stage. This study investigated the independence and interaction between perceptual and central attention. To do so, I used a dual-task paradigm, pairing a four-alternative choice task with a visual search task. The results showed that central attention for response selection was engaged in perceptual processing for visual search when the number of search items increased, thereby increasing the demand for serial allocation of focal attention. By contrast, central attention and perceptual attention remained independent as far as the demand for serial shifting of focal attention remained constant; decreasing stimulus contrast or increasing the set size of a parallel search did not evoke the involvement of central attention in visual search. These results suggest that the nature of concurrent visual search process plays a crucial role in the functional interaction between two different types of attention.

Indocyanine Green Fluorescence for Free-Flap Perfusion Imaging Revisited: Advanced Decision Making by Virtual Perfusion Reality in Visionsense Fusion Imaging Angiography.

PubMed

Bigdeli, Amir Khosrow; Gazyakan, Emre; Schmidt, Volker Juergen; Hernekamp, Frederick Jochen; Harhaus, Leila; Henzler, Thomas; Kremer, Thomas; Kneser, Ulrich; Hirche, Christoph

2016-06-01

Near-infrared indocyanine green video angiography (ICG-NIR-VA) has been introduced for free-flap surgery and may provide intraoperative flap designing as well as postoperative monitoring. Nevertheless, the technique has not been established in clinical routine because of controversy over benefits. Improved technical features of the novel Visionsense ICG-NIR-VA surgery system are promising to revisit the field of application. It features a unique real-time fusion image of simultaneous NIR and white light visualization, with highlighted perfusion, including a color-coded perfusion flow scale for optimized anatomical understanding. In a feasibility study, the Visionsense ICG-NIR-VA system was applied during 10 free-flap surgeries in 8 patients at our center. Indications included anterior lateral thigh (ALT) flap (n = 4), latissimus dorsi muscle flap (n = 1), tensor fascia latae flap (n = 1), and two bilateral deep inferior epigastric artery perforator flaps (n = 4). The system was used intraoperatively and postoperatively to investigate its impact on surgical decision making and to observe perfusion patterns correlated to clinical monitoring. Visionsense ICG-NIR-VA aided assessing free-flap design and perfusion patterns in all cases and correlated with clinical observations. Additional interventions were performed in 2 cases (22%). One venous anastomosis was revised, and 1 flap was redesigned. Indicated by ICG-NIR-VA, 1 ALT flap developed partial flap necrosis (11%). The Visionsense ICG-NIR-VA system allowed a virtual view of flap perfusion anatomy by fusion imaging in real-time. The system improved decision making for flap design and surgical decisions. Clinical and ICG-NIR-VA parameters correlated. Its future implementation may aid in improving outcomes for free-flap surgery, but additional experience is needed to define its final role. © The Author(s) 2015.

Erythropoietin in Treatment of Methanol Optic Neuropathy.

PubMed

Pakdel, Farzad; Sanjari, Mostafa S; Naderi, Asieh; Pirmarzdashti, Niloofar; Haghighi, Anousheh; Kashkouli, Mohsen B

2018-06-01

Methanol poisoning can cause an optic neuropathy that is usually severe and irreversible and often occurs after ingestion of illicit or homemade alcoholic beverages. In this study, we evaluated the potential neuroprotective effect of erythropoietin (EPO) on visual acuity (VA) in patients with methanol optic neuropathy. In a prospective, noncomparative interventional case series, consecutive patients with methanol optic neuropathy after alcoholic beverage ingestion were included. All patients initially received systemic therapy including metabolic stabilization and detoxification. Treatment with intravenous recombinant human EPO consisted of 20,000 units/day for 3 successive days. Depending on clinical response, some patients received a second course of EPO. VA, funduscopy, and spectral domain optical coherence tomography were assessed during the study. Main outcome measure was VA. Thirty-two eyes of 16 patients with methanol optic neuropathy were included. Mean age was 34.2 years (±13.3 years). The mean time interval between methanol ingestion and treatment with intravenous EPO was 9.1 days (±5.56 days). Mean follow-up after treatment was 7.5 months (±5.88 months). Median VA in the better eye of each patient before treatment was light perception (range: 3.90-0.60 logMAR). Median last acuity after treatment in the best eye was 1.00 logMAR (range: 3.90-0.00 logMAR). VA significantly increased in the last follow-up examination (P < 0.0001). Age and time to EPO treatment after methanol ingestion were not significantly related to final VA. No ocular or systemic complications occurred in our patient cohort. Intravenous EPO appears to improve VA in patients with methanol optic neuropathy and may represent a promising treatment for this disorder.

Conscious visual memory with minimal attention.

PubMed

Pinto, Yair; Vandenbroucke, Annelinde R; Otten, Marte; Sligte, Ilja G; Seth, Anil K; Lamme, Victor A F

2017-02-01

Is conscious visual perception limited to the locations that a person attends? The remarkable phenomenon of change blindness, which shows that people miss nearly all unattended changes in a visual scene, suggests the answer is yes. However, change blindness is found after visual interference (a mask or a new scene), so that subjects have to rely on working memory (WM), which has limited capacity, to detect the change. Before such interference, however, a much larger capacity store, called fragile memory (FM), which is easily overwritten by newly presented visual information, is present. Whether these different stores depend equally on spatial attention is central to the debate on the role of attention in conscious vision. In 2 experiments, we found that minimizing spatial attention almost entirely erases visual WM, as expected. Critically, FM remains largely intact. Moreover, minimally attended FM responses yield accurate metacognition, suggesting that conscious memory persists with limited spatial attention. Together, our findings help resolve the fundamental issue of how attention affects perception: Both visual consciousness and memory can be supported by only minimal attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effect of post-discharge follow-up care on re-admissions among US veterans with congestive heart failure: a rural-urban comparison.

PubMed

Muus, Kyle J; Knudson, Alana; Klug, Marilyn G; Gokun, Jane; Sarrazin, Mary; Kaboli, Peter

2010-01-01

Hospital re-admissions for patients with congestive heart failure (CHF) are relatively common and costly occurrences within the US health infrastructure, including the Veterans Affairs (VA) healthcare system. Little is known about CHF re-admissions among rural veteran patients, including the effects of socio-demographics and follow-up outpatient visits on these re-admissions. To examine socio-demographics of US veterans with CHF who had 30 day potentially preventable re-admissions and compare the effect of 30 day VA post-discharge service use on these re-admissions for rural- and urban-dwelling veterans. The 2005-2007 VA data were analyzed to examine patient characteristics and hospital admissions for 36 566 veterans with CHF. The CHF patients who were and were not re-admitted to a VA hospital within 30 days of discharge were identified. Logistic regression was used to examine and compare the effect of VA post-acute service use on re-admissions between rural- and urban-dwelling veterans. Re-admitted veterans tended to be older (p=.002), had disability status (p=.024) and had longer hospital stays (p<.001). Veterans Affairs follow-up visits were negatively associated with re-admissions for both rural and urban veterans with CHF (ORs 0.16-0.76). Rural veterans aged 65 years and older who had VA emergency room visits following discharge were at high risk for re-admission (OR=2.66). Post-acute follow-up care is an important factor for promoting recovery and good health among hospitalized veterans with CHF, regardless of their rural or urban residence. Older, rural veterans with CHF are in need of special attention for VA discharge planning and follow up with primary care providers.

Low-level visual attention and its relation to joint attention in autism spectrum disorder.

PubMed

Jaworski, Jessica L Bean; Eigsti, Inge-Marie

2017-04-01

Visual attention is integral to social interaction and is a critical building block for development in other domains (e.g., language). Furthermore, atypical attention (especially joint attention) is one of the earliest markers of autism spectrum disorder (ASD). The current study assesses low-level visual attention and its relation to social attentional processing in youth with ASD and typically developing (TD) youth, aged 7 to 18 years. The findings indicate difficulty overriding incorrect attentional cues in ASD, particularly with non-social (arrow) cues relative to social (face) cues. The findings also show reduced competition in ASD from cues that remain on-screen. Furthermore, social attention, autism severity, and age were all predictors of competing cue processing. The results suggest that individuals with ASD may be biased towards speeded rather than accurate responding, and further, that reduced engagement with visual information may impede responses to visual attentional cues. Once attention is engaged, individuals with ASD appear to interpret directional cues as meaningful. These findings from a controlled, experimental paradigm were mirrored in results from an ecologically valid measure of social attention. Attentional difficulties may be exacerbated during the complex and dynamic experience of actual social interaction. Implications for intervention are discussed.

Spatial attention increases high-frequency gamma synchronisation in human medial visual cortex.

PubMed

Koelewijn, Loes; Rich, Anina N; Muthukumaraswamy, Suresh D; Singh, Krish D

2013-10-01

Visual information processing involves the integration of stimulus and goal-driven information, requiring neuronal communication. Gamma synchronisation is linked to neuronal communication, and is known to be modulated in visual cortex both by stimulus properties and voluntarily-directed attention. Stimulus-driven modulations of gamma activity are particularly associated with early visual areas such as V1, whereas attentional effects are generally localised to higher visual areas such as V4. The absence of a gamma increase in early visual cortex is at odds with robust attentional enhancements found with other measures of neuronal activity in this area. Here we used magnetoencephalography (MEG) to explore the effect of spatial attention on gamma activity in human early visual cortex using a highly effective gamma-inducing stimulus and strong attentional manipulation. In separate blocks, subjects tracked either a parafoveal grating patch that induced gamma activity in contralateral medial visual cortex, or a small line at fixation, effectively attending away from the gamma-inducing grating. Both items were always present, but rotated unpredictably and independently of each other. The rotating grating induced gamma synchronisation in medial visual cortex at 30-70 Hz, and in lateral visual cortex at 60-90 Hz, regardless of whether it was attended. Directing spatial attention to the grating increased gamma synchronisation in medial visual cortex, but only at 60-90 Hz. These results suggest that the generally found increase in gamma activity by spatial attention can be localised to early visual cortex in humans, and that stimulus and goal-driven modulations may be mediated at different frequencies within the gamma range. Copyright © 2013 Elsevier Inc. All rights reserved.

Cognitive Control Network Contributions to Memory-Guided Visual Attention

PubMed Central

Rosen, Maya L.; Stern, Chantal E.; Michalka, Samantha W.; Devaney, Kathryn J.; Somers, David C.

2016-01-01

Visual attentional capacity is severely limited, but humans excel in familiar visual contexts, in part because long-term memories guide efficient deployment of attention. To investigate the neural substrates that support memory-guided visual attention, we performed a set of functional MRI experiments that contrast long-term, memory-guided visuospatial attention with stimulus-guided visuospatial attention in a change detection task. Whereas the dorsal attention network was activated for both forms of attention, the cognitive control network (CCN) was preferentially activated during memory-guided attention. Three posterior nodes in the CCN, posterior precuneus, posterior callosal sulcus/mid-cingulate, and lateral intraparietal sulcus exhibited the greatest specificity for memory-guided attention. These 3 regions exhibit functional connectivity at rest, and we propose that they form a subnetwork within the broader CCN. Based on the task activation patterns, we conclude that the nodes of this subnetwork are preferentially recruited for long-term memory guidance of visuospatial attention. PMID:25750253

Visual acuity and central retinal thickness: fulfilment of retreatment criteria for recurrent neovascular AMD in routine clinical care.

PubMed

Reznicek, Lukas; Muhr, Johanna; Ulbig, Michael; Kampik, Anselm; Mayer, Wolfgang J; Haritoglou, Christos; Neubauer, Aljoscha; Wolf, Armin

2014-10-01

To evaluate the fulfillment of retreatment criteria in recurrent neovascular age-related macular degeneration (nAMD) for a pro-re-nata treatment regime with ranibizumab in routine clinical care. Data from patients with treatment-naive nAMD were analysed retrospectively. As an 'upload', all patients had received three-monthly intravitreal ranibizumab injections in a university eye hospital and were then seen by ophthalmologists in private practice who referred them back in case of recurrence. Recurrence was defined as a decrease of visual acuity (VA) of one line or more (functional retreatment criteria), a central retinal thickness (CRT) increase of at least 100 µm upon Optical Coherence Tomography (OCT) examination (morphological retreatment criteria) or a new macular haemorrhage (clinical retreatment criteria). We included 92 patients (36 men and 56 women). The mean VA before retreatment of a recurrence was -0.63 ± 0.33 logMAR and improved significantly (p<0.001) by 0.10 ± 0.16 logMAR to -0.53 ± 0.28 logMAR thereafter. Mean CRT before retreatment was 278.07 ± 87.56 µm and decreased significantly (p<0.001) by 71.22 ± 106.93 to 206.85 ± 60.30 µm. Evaluation of the fulfillment of retreatment criteria revealed functional retreatment criteria in 82.6% of patients. However, upon re-evaluation of VA using Early Treatment Diabetic Retinopathy Study (ETDRS) charts in the treatment centre, mean decrease of VA was 10 letters as compared with the end of upload therapy. All patients presented an increased CRT when treated for recurrence of nAMD (mean increase 69.47 µm), but the morphological retreatment criteria (CRT increase of 100 µm or more) were fulfilled in only 44.4% of patients upon Spectral Domain OCT (SD-OCT) evaluation in the treatment centre. In a routine clinical care, evaluation of VA using ETDRS charts seems to be more sensitive than Snellen VA testing. Quantitative OCT-based retreatment criteria (eg, increase of CRT of 100 µm or more) appear to be not sensitive enough in a clinical setting with referring ophthalmologists. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

An epidemiological approach for the estimation of disease onset in Central Europe in central and peripheral monogenic retinal dystrophies.

PubMed

Prokofyeva, Elena; Wilke, Robert; Lotz, Gunnar; Troeger, Eric; Strasser, Torsten; Zrenner, Eberhart

2009-07-01

To study clinical patterns of disease onset in monogenic retinal dystrophies (MRD), using an epidemiological approach. Records of patients with MRD, seen at the University Eye Hospital Tuebingen from 1994 to 1999, were selected from a database and retrospectively reviewed. For analysis, patients were divided into 2 groups by predominant part of visual field (VF) involvement: group 1 (predominantly central involvement) included Stargardt disease (ST), macular dystrophy (MD), and central areolar choroidal dystrophy (CACD), and group 2 (predominantly peripheral involvement) included Bardet-Biedl syndrome (BBD), Usher syndrome (USH) I and II, and choroideremia (CHD). Age, sex, age of first diagnosis, age of visual acuity (VA) decrease and VF emergence, night blindness and photophobia onset, types of VF defects and age of its onset, color discrimination defects and best corrected VA were analyzed. Records of 259 patients were studied. Men were more prevalent than women. Mean age of the patients was 47.2 (SD = 15.6) years old. Forty-five patients in the first group and 40 in the second were first diagnosed between 21 and 30 years of age. Ninety-four patients in the first group had VA decrease before 30 years of age; in the second group, 68 patients had VA decrease onset between 21 and 40 years of age. Forty-four patients in the first group noticed VF at an age between 21 and 30 years, and 74 patients between 11 and 30 years in the second group. Central scotoma was typical for the first group, and was detected in 115 patients. Concentric constriction was typical for the second group, and was found in 81 patients. Half of patients in both groups preserved best-corrected VA in the better eye at a level of 20/40 or better; 7% in the first group and 6% in the second group were registered as legally blind according to WHO criteria, having VA <1/50 or VF <5 degrees . Diagnosis frequency was USH I and II-34%, ST-31%, MD-18%, CHD-14%, BBD-5%. An epidemiological approach to the estimation of the disease onset of various subtypes of monogenic retinal degenerations will be useful for detection of disease duration, its prognosis, rehabilitation and the researching of future treatment possibilities.

Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice.

PubMed

Mishra, S; Chawla, D; Agarwal, R; Deorari, A K; Paul, V K; Bhutani, V K

2009-12-01

We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates. Newborns, > or =35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines). A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: -8.9%, 95% CI: -2.4% to -15.4%; p = 0.008). Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874).

Comparing Visual and Statistical Analysis in Single-Case Studies Using Published Studies

PubMed Central

Harrington, Magadalena; Velicer, Wayne F.

2015-01-01

Little is known about the extent to which interrupted time-series analysis (ITSA) can be applied to short, single-case study designs and whether those applications produce results consistent with visual analysis (VA). This paper examines the extent to which ITSA can be applied to single-case study designs and compares the results based on two methods: ITSA and VA, using papers published in the Journal of Applied Behavior Analysis in 2010. The study was made possible by the development of software called UnGraph® which facilitates the recovery of raw data from the graphs. ITSA was successfully applied to 94% of the examined graphs with the number of observations ranging from 8 to 136. Moderate to high lag 1 autocorrelations (> .50) were found for 46% of the data series. Effect sizes similar to group-level Cohen’s d were identified based on the tertile distribution. Effects ranging from 0.00 to 0.99 were classified as small, those ranging from 1.00 to 2.49 as medium, and large effect sizes were defined as 2.50 or greater. Comparison of the conclusions from VA and ITSA had a low level of agreement (Kappa = .14, accounting for the agreement expected by chance). The results demonstrate that ITSA can be broadly implemented in applied behavior analysis research. These two methods should be viewed as complimentary and used concurrently. PMID:26609876

A Neural Theory of Visual Attention: Bridging Cognition and Neurophysiology

ERIC Educational Resources Information Center

Bundesen, Claus; Habekost, Thomas; Kyllingsbaek, Soren

2005-01-01

A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing resources (cells) are devoted to behaviorally…

Is There a Common Linkage among Reading Comprehension, Visual Attention, and Magnocellular Processing?

ERIC Educational Resources Information Center

Solan, Harold A.; Shelley-Tremblay, John F.; Hansen, Peter C.; Larson, Steven

2007-01-01

The authors examined the relationships between reading comprehension, visual attention, and magnocellular processing in 42 Grade 7 students. The goal was to quantify the sensitivity of visual attention and magnocellular visual processing as concomitants of poor reading comprehension in the absence of either vision therapy or cognitive…

Spatial Working Memory Interferes with Explicit, but Not Probabilistic Cuing of Spatial Attention

ERIC Educational Resources Information Center

Won, Bo-Yeong; Jiang, Yuhong V.

2015-01-01

Recent empirical and theoretical work has depicted a close relationship between visual attention and visual working memory. For example, rehearsal in spatial working memory depends on spatial attention, whereas adding a secondary spatial working memory task impairs attentional deployment in visual search. These findings have led to the proposal…

Small-Gauge Pars Plana Vitrectomy for the Management of Symptomatic Posterior Vitreous Detachment after Phacoemulsification and Multifocal Intraocular Lens Implantation: A Pilot Study from the Pan-American Collaborative Retina Study Group

PubMed Central

Navarro, Rodrigo M.; Machado, Leonardo M.; Maia, Ossires; Wu, Lihteh; Farah, Michel E.; Magalhaes, Octaviano; Arevalo, J. Fernando; Maia, Mauricio

2015-01-01

Purpose. To determine the efficacy of 23-gauge pars plana vitrectomy (PPV) for symptomatic posterior vitreous detachment (PVD) on visual acuity (VA) and quality after multifocal intraocular lenses (IOLs). Methods. In this prospective case series, patients who developed symptomatic PVD and were not satisfied with visual quality due to floaters and halos after multifocal IOL implantation underwent PPV. Examinations included LogMAR uncorrected visual acuity (UCVA), intraocular pressure, biomicroscopy, and indirect ophthalmoscopy at baseline and 1, 7, 30, and 180 days postoperatively. Ultrasonography and aberrometry were performed. The Visual Functioning Questionnaire 25 (VFQ-25) was administered preoperatively and at 30 days postoperatively. Both the postoperative UCVA and questionnaire results were compared to preoperative findings using the Wilcoxon test. Results. Sixteen eyes of 8 patients were included. VA significantly improved from 0.17 to 0.09 postoperatively (P = 0.017). All patients reported improvement of halos, glare, and floaters. VFQ-25 scores significantly improved in general vision (P = 0.023), near activities (P = 0.043), distance activities (P = 0.041), mental health (P = 0.011), role difficulties (P = 0.042), and driving (P = 0.016). Conclusion. PPV may increase UCVA and quality of vision in patients with bilateral multifocal IOLs and symptomatic PVD. Larger studies are advised. PMID:26504590

[Perimetric changes in advanced glaucoma].

PubMed

Feraru, Crenguta Ioana; Pantalon, Anca

2011-01-01

The evaluation of various perimetric aspects in advanced glaucoma stages correlated to morpho-functional changes. MATHERIAL AND METHOD: Retrospective clinical trial over a 10 months time period that included patients with advanced glaucoma stages, for which there have been recorded several computerised visual field tests (central 24-2 strategy, 10-2 strategy with either III or V--Goldman stimulus spot size) along with other morpho-funtional ocular paramaters: VA, lOP optic disk analysis. We included in our study 56 eyes from 45 patients. In most cases 89% it was an open angle glaucoma (either primary or secondary) Mean visual acuity was 0.45 +/- 0.28. Regarding the perimetric deficit 83% had advanced deficit, 9% moderate and 8% early visual changes. As perimetric type of defect we found a majority with general reduction of sensitivity (33 eyes) + ring shape scotoma. In 6 eyes (10.7%) having left only a central isle of vision we performed the central 10-2 strategy with III or V Goldmann stimulus spot size. Statistic analysis showed scarce correlation between the visual acuity and the quantitative perimetric parameters (MD and PSD), and variance analysis found present a multiple correlation parameter p = 0.07 that proves there is no liniary correspondence between the morpho-functional parameters: VA-MD(PSD) and C/D ratio. In advanced glaucoma stages, the perimetric changes are mostly severe. Perimetric evaluation is essential in these stages and needs to be individualised.

Pattern visual evoked potentials in eyes with disc swelling due to cat scratch disease-associated neuroretinitis.

PubMed

Chai, Yuzhu; Yamamoto, Shuichi; Hirayama, Atsuko; Yotsukura, Jiro; Yamazaki, Hiroko

2005-01-01

To evaluate optic nerve function by pattern visual evoked potentials (VEPs) in eyes with optic disc swelling due to neuroretinitis associated with cat scratch disease (CSD). Four eyes of four patients with marked optic disc swelling resembling optic neuritis but diagnosed serologically as CSD received systemic steroid treatment. VEPs elicited by black and white checkerboard stimuli created on a TV monitor were recorded before the treatment. The visual acuity (VA) in the affected eyes was decreased to 20/50 in two eyes and finger counting in two eyes at their initial visits. Ophthalmoscopic examination revealed neuroretinitis characterized by severe optic disc swelling, chorioretinal exudates, and macular edema in all eyes. Anti-Bartonella henselae serum antibody was markedly elevated in all patients confirming the diagnosis of CSD. The P100 of the transient VEPs was only mildly reduced without a delay in the implicit times in three eyes and only slightly delayed in the other eye. The steady-state VEPs were mildly reduced in two eyes and phase-reversed in other two eyes. The VA fully recovered after systemic steroid treatment in all patients. Although all examined patients showed marked swelling of the optic disc and visual decrease, the pattern VEPs were not affected as severely as in idiopathic optic neuritis. However, the degree of change of the pattern VEPs varied among patients.

Selective visual attention to emotional words: Early parallel frontal and visual activations followed by interactive effects in visual cortex.

PubMed

Schindler, Sebastian; Kissler, Johanna

2016-10-01

Human brains spontaneously differentiate between various emotional and neutral stimuli, including written words whose emotional quality is symbolic. In the electroencephalogram (EEG), emotional-neutral processing differences are typically reflected in the early posterior negativity (EPN, 200-300 ms) and the late positive potential (LPP, 400-700 ms). These components are also enlarged by task-driven visual attention, supporting the assumption that emotional content naturally drives attention. Still, the spatio-temporal dynamics of interactions between emotional stimulus content and task-driven attention remain to be specified. Here, we examine this issue in visual word processing. Participants attended to negative, neutral, or positive nouns while high-density EEG was recorded. Emotional content and top-down attention both amplified the EPN component in parallel. On the LPP, by contrast, emotion and attention interacted: Explicit attention to emotional words led to a substantially larger amplitude increase than did explicit attention to neutral words. Source analysis revealed early parallel effects of emotion and attention in bilateral visual cortex and a later interaction of both in right visual cortex. Distinct effects of attention were found in inferior, middle and superior frontal, paracentral, and parietal areas, as well as in the anterior cingulate cortex (ACC). Results specify separate and shared mechanisms of emotion and attention at distinct processing stages. Hum Brain Mapp 37:3575-3587, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Haptic over visual information in the distribution of visual attention after tool-use in near and far space.

PubMed

Park, George D; Reed, Catherine L

2015-10-01

Despite attentional prioritization for grasping space near the hands, tool-use appears to transfer attentional bias to the tool's end/functional part. The contributions of haptic and visual inputs to attentional distribution along a tool were investigated as a function of tool-use in near (Experiment 1) and far (Experiment 2) space. Visual attention was assessed with a 50/50, go/no-go, target discrimination task, while a tool was held next to targets appearing near the tool-occupied hand or tool-end. Target response times (RTs) and sensitivity (d-prime) were measured at target locations, before and after functional tool practice for three conditions: (1) open-tool: tool-end visible (visual + haptic inputs), (2) hidden-tool: tool-end visually obscured (haptic input only), and (3) short-tool: stick missing tool's length/end (control condition: hand occupied but no visual/haptic input). In near space, both open- and hidden-tool groups showed a tool-end, attentional bias (faster RTs toward tool-end) before practice; after practice, RTs near the hand improved. In far space, the open-tool group showed no bias before practice; after practice, target RTs near the tool-end improved. However, the hidden-tool group showed a consistent tool-end bias despite practice. Lack of short-tool group results suggested that hidden-tool group results were specific to haptic inputs. In conclusion, (1) allocation of visual attention along a tool due to tool practice differs in near and far space, and (2) visual attention is drawn toward the tool's end even when visually obscured, suggesting haptic input provides sufficient information for directing attention along the tool.

Pulmonary Testing Laboratory Computer Application

PubMed Central

Johnson, Martin E.

1980-01-01

An interactive computer application reporting patient pulmonary function data has been developed by Washington, D.C. VA Medical Center staff. A permanent on-line data base of patient demographics, lung capacity, flows, diffusion, arterial blood gases and physician interpretation is maintained by a minicomputer at the hospital. A user oriented application program resulted from development in concert with the clinical users. Rapid program development resulted from employing a newly developed time saving technique that has found wide application at other VA Medical Centers. Careful attention to user interaction has resulted in an application program requiring little training and which has been satisfactorily used by a number of clinicians.

Video game experience and its influence on visual attention parameters: an investigation using the framework of the Theory of Visual Attention (TVA).

PubMed

Schubert, Torsten; Finke, Kathrin; Redel, Petra; Kluckow, Steffen; Müller, Hermann; Strobach, Tilo

2015-05-01

Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice. Copyright © 2015 Elsevier B.V. All rights reserved.

Neural practice effect during cross-modal selective attention: Supra-modal and modality-specific effects.

PubMed

Xia, Jing; Zhang, Wei; Jiang, Yizhou; Li, You; Chen, Qi

2018-05-16

Practice and experiences gradually shape the central nervous system, from the synaptic level to large-scale neural networks. In natural multisensory environment, even when inundated by streams of information from multiple sensory modalities, our brain does not give equal weight to different modalities. Rather, visual information more frequently receives preferential processing and eventually dominates consciousness and behavior, i.e., visual dominance. It remains unknown, however, the supra-modal and modality-specific practice effect during cross-modal selective attention, and moreover whether the practice effect shows similar modality preferences as the visual dominance effect in the multisensory environment. To answer the above two questions, we adopted a cross-modal selective attention paradigm in conjunction with the hybrid fMRI design. Behaviorally, visual performance significantly improved while auditory performance remained constant with practice, indicating that visual attention more flexibly adapted behavior with practice than auditory attention. At the neural level, the practice effect was associated with decreasing neural activity in the frontoparietal executive network and increasing activity in the default mode network, which occurred independently of the modality attended, i.e., the supra-modal mechanisms. On the other hand, functional decoupling between the auditory and the visual system was observed with the progress of practice, which varied as a function of the modality attended. The auditory system was functionally decoupled with both the dorsal and ventral visual stream during auditory attention while was decoupled only with the ventral visual stream during visual attention. To efficiently suppress the irrelevant visual information with practice, auditory attention needs to additionally decouple the auditory system from the dorsal visual stream. The modality-specific mechanisms, together with the behavioral effect, thus support the visual dominance model in terms of the practice effect during cross-modal selective attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid Assessment of Visual Impairment in Urban Population of Delhi, India

PubMed Central

Gupta, Noopur; Vashist, Praveen; Malhotra, Sumit; Senjam, Suraj Singh; Misra, Vasundhara; Bhardwaj, Amit

2015-01-01

Purpose To determine the prevalence, causes and associated demographic factors related to visual impairment amongst the urban population of New Delhi, India. Methods A population-based, cross-sectional study was conducted in East Delhi district using cluster random sampling methodology. This Rapid Assessment of Visual Impairment (RAVI) survey involved examination of all individuals aged 40 years and above in 24 randomly selected clusters of the district. Visual acuity (VA) assessment and comprehensive ocular examination were done during the door-to-door survey. A questionnaire was used to collect personal and demographic information of the study population. Blindness and Visual Impairment was defined as presenting VA <3/60and <6/18 in the better eye, respectively. Descriptive statistics were computed along with multivariable logistic regression analysis to determine associated factors for visual impairment. Results Of 2421 subjects enumerated, 2331 (96.3%) were available for ophthalmic examination. Among those examined, 49.3% were males. The prevalence of visual impairment (VI) in the study population, was 11.4% (95% C.I. 10.1, 12.7) and that of blindness was 1.2% (95% C.I. 0.8, 1.6). Uncorrected refractive error was the leading cause of VI accounting for 53.4% of all VI followed by cataract (33.8%). With multivariable logistic regression, the odds of having VI increased with age (OR= 24.6[95% C.I.: 14.9, 40.7]; p<0.001). Illiterate participants were more likely to have VI [OR= 1.5 (95% C.I.: 1.1,2.1)] when compared to educated participants. Conclusions The first implementation of the RAVI methodology in a North Indian population revealed that the burden of visual impairment is considerable in this region despite availability of adequate eye care facilities. Awareness generation and simple interventions like cataract surgery and provision of spectacles will help to eliminate the major causes of blindness and visual impairment in this region. PMID:25915659

Rapid assessment of visual impairment in urban population of Delhi, India.

PubMed

Gupta, Noopur; Vashist, Praveen; Malhotra, Sumit; Senjam, Suraj Singh; Misra, Vasundhara; Bhardwaj, Amit

2015-01-01

To determine the prevalence, causes and associated demographic factors related to visual impairment amongst the urban population of New Delhi, India. A population-based, cross-sectional study was conducted in East Delhi district using cluster random sampling methodology. This Rapid Assessment of Visual Impairment (RAVI) survey involved examination of all individuals aged 40 years and above in 24 randomly selected clusters of the district. Visual acuity (VA) assessment and comprehensive ocular examination were done during the door-to-door survey. A questionnaire was used to collect personal and demographic information of the study population. Blindness and Visual Impairment was defined as presenting VA < 3/60 and < 6/18 in the better eye, respectively. Descriptive statistics were computed along with multivariable logistic regression analysis to determine associated factors for visual impairment. Of 2421 subjects enumerated, 2331 (96.3%) were available for ophthalmic examination. Among those examined, 49.3% were males. The prevalence of visual impairment (VI) in the study population, was 11.4% (95% C.I. 10.1, 12.7) and that of blindness was 1.2% (95% C.I. 0.8, 1.6). Uncorrected refractive error was the leading cause of VI accounting for 53.4% of all VI followed by cataract (33.8%). With multivariable logistic regression, the odds of having VI increased with age (OR = 24.6[95% C.I.: 14.9, 40.7]; p < 0.001). Illiterate participants were more likely to have VI [OR = 1.5 (95% C.I.: 1.1,2.1)] when compared to educated participants. The first implementation of the RAVI methodology in a North Indian population revealed that the burden of visual impairment is considerable in this region despite availability of adequate eye care facilities. Awareness generation and simple interventions like cataract surgery and provision of spectacles will help to eliminate the major causes of blindness and visual impairment in this region.

Should tumbling E go out of date in amblyopia screening? Evidence from a population-based sample normative in children aged 3-4 years.

PubMed

Guimaraes, Sandra; Fernandes, Tiago; Costa, Patrício; Silva, Eduardo

2018-06-01

To determine a normative of tumbling E optotype and its feasibility for visual acuity (VA) assessment in children aged 3-4 years. A cross-sectional study of 1756 children who were invited to participate in a comprehensive non-invasive eye exam. Uncorrected monocular VA with crowded tumbling E with a comprehensive ophthalmological examination were assessed. Testability rates of the whole population and VA of the healthy children for different age subgroups, gender, school type and the order of testing in which the ophthalmological examination was performed were evaluated. The overall testability rate was 95% (92% and 98% for children aged 3 and 4 years, respectively). The mean VA of the first-day assessment (first-VA) and best-VA over 2 days' assessments was 0.14 logMAR (95% CI 0.14 to 0.15) (decimal=0.72, 95% CI 0.71 to 0.73) and 0.13 logMAR (95% CI 0.13 to 0.14) (decimal=0.74, 95% CI 0.73 to 0.74). Analysis with age showed differences between groups in first-VA (F(3,1146)=10.0; p<0.001; η2=0.026) and best-VA (F(3,1155)=8.8; p<0.001; η2=0.022). Our normative was very highly correlated with previous reported HOTV-Amblyopia-Treatment-Study (HOTV-ATS) (first-VA, r=0.97; best-VA, r=0.99), with 0.8 to 0.7 lines consistent overestimation for HOTV-ATS as described in literature. Overall false-positive referral was 1.3%, being specially low regarding anisometropias of ≥2 logMAR lines (0.17%). Interocular difference ≥1 line VA logMAR was not associated with age (p=0.195). This is the first normative for European Caucasian children with single crowded tumbling E in healthy eyes and the largest study comparing 3 and 4 years old testability. Testability rates are higher than found in literature with other optotypes, especially in children aged 3 years, where we found 5%-11% better testability rates. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Guidance of visual attention by semantic information in real-world scenes

PubMed Central

Wu, Chia-Chien; Wick, Farahnaz Ahmed; Pomplun, Marc

2014-01-01

Recent research on attentional guidance in real-world scenes has focused on object recognition within the context of a scene. This approach has been valuable for determining some factors that drive the allocation of visual attention and determine visual selection. This article provides a review of experimental work on how different components of context, especially semantic information, affect attentional deployment. We review work from the areas of object recognition, scene perception, and visual search, highlighting recent studies examining semantic structure in real-world scenes. A better understanding on how humans parse scene representations will not only improve current models of visual attention but also advance next-generation computer vision systems and human-computer interfaces. PMID:24567724

Respiratory comfort and breathing pattern during volume proportional assist ventilation and pressure support ventilation: a study on volunteers with artificially reduced compliance.

PubMed

Mols, G; von Ungern-Sternberg, B; Rohr, E; Haberthür, C; Geiger, K; Guttmann, J

2000-06-01

To assess respiratory comfort and associated breathing pattern during volume assist (VA) as a component of proportional assist ventilation and during pressure support ventilation (PSV). Prospective, double-blind, interventional study. Laboratory. A total of 15 healthy volunteers (11 females, 4 males) aged 21-31 yrs. Decreased respiratory system compliance was simulated by banding of the thorax and abdomen. Volunteers breathed via a mouthpiece with VA and PSV each applied at two levels (VA, 8 cm H2O/L and 12 cm H2O/L; PSV, 10 cm H2O and 15 cm H2O) using a positive end-expiratory pressure of 5 cm H2O throughout. The study was subdivided into two parts. In Part 1, volunteers breathed three times with each of the four settings for 2 mins in random order. In Part 2, the first breath effects of multiple, randomly applied mode, and level shifts were studied. In Part 1, the volunteers were asked to estimate respiratory comfort in comparison with normal breathing using a visual analog scale. In Part 2, they were asked to estimate the change of respiratory comfort as increased, decreased, or unchanged immediately after a mode shift. Concomitantly, the respiratory pattern (change) was characterized with continuously measured tidal volume, respiratory rate, pressure, and gas flow. Respiratory comfort during VA was higher than during PSV. The higher support level was less important during VA but had a major negative influence on comfort during PSV. Both modes differed with respect to the associated breathing pattern. Variability of breathing was higher during VA than during PSV (Part 1). Changes in respiratory variables were associated with changes in respiratory comfort (Part 2). For volunteers breathing with artificially reduced respiratory system compliance, respiratory comfort is higher with VA than with PSV. This is probably caused by a better adaptation of the ventilatory support to the volunteer's need with VA.

Attentional bias to food-related visual cues: is there a role in obesity?

PubMed

Doolan, K J; Breslin, G; Hanna, D; Gallagher, A M

2015-02-01

The incentive sensitisation model of obesity suggests that modification of the dopaminergic associated reward systems in the brain may result in increased awareness of food-related visual cues present in the current food environment. Having a heightened awareness of these visual food cues may impact on food choices and eating behaviours with those being most aware of or demonstrating greater attention to food-related stimuli potentially being at greater risk of overeating and subsequent weight gain. To date, research related to attentional responses to visual food cues has been both limited and conflicting. Such inconsistent findings may in part be explained by the use of different methodological approaches to measure attentional bias and the impact of other factors such as hunger levels, energy density of visual food cues and individual eating style traits that may influence visual attention to food-related cues outside of weight status alone. This review examines the various methodologies employed to measure attentional bias with a particular focus on the role that attentional processing of food-related visual cues may have in obesity. Based on the findings of this review, it appears that it may be too early to clarify the role visual attention to food-related cues may have in obesity. Results however highlight the importance of considering the most appropriate methodology to use when measuring attentional bias and the characteristics of the study populations targeted while interpreting results to date and in designing future studies.

Attention Effects During Visual Short-Term Memory Maintenance: Protection or Prioritization?

PubMed Central

Matsukura, Michi; Luck, Steven J.; Vecera, Shaun P.

2007-01-01

Interactions between visual attention and visual short-term memory (VSTM) play a central role in cognitive processing. For example, attention can assist in selectively encoding items into visual memory. Attention appears to be able to influence items already stored in visual memory as well; cues that appear long after the presentation of an array of objects can affect memory for those objects (Griffin & Nobre, 2003). In five experiments, we distinguished two possible mechanisms for the effects of cues on items currently stored in VSTM. A protection account proposes that attention protects the cued item from becoming degraded during the retention interval. By contrast, a prioritization account suggests that attention increases a cued item’s priority during the comparison process that occurs when memory is tested. The results of the experiments were consistent with the first of these possibilities, suggesting that attention can serve to protect VSTM representations while they are being maintained. PMID:18078232

Attention distributed across sensory modalities enhances perceptual performance

PubMed Central

Mishra, Jyoti; Gazzaley, Adam

2012-01-01

This study investigated the interaction between top-down attentional control and multisensory processing in humans. Using semantically congruent and incongruent audiovisual stimulus streams, we found target detection to be consistently improved in the setting of distributed audiovisual attention versus focused visual attention. This performance benefit was manifested as faster reaction times for congruent audiovisual stimuli, and as accuracy improvements for incongruent stimuli, resulting in a resolution of stimulus interference. Electrophysiological recordings revealed that these behavioral enhancements were associated with reduced neural processing of both auditory and visual components of the audiovisual stimuli under distributed vs. focused visual attention. These neural changes were observed at early processing latencies, within 100–300 ms post-stimulus onset, and localized to auditory, visual, and polysensory temporal cortices. These results highlight a novel neural mechanism for top-down driven performance benefits via enhanced efficacy of sensory neural processing during distributed audiovisual attention relative to focused visual attention. PMID:22933811

A Comparison of the Visual Attention Patterns of People with Aphasia and Adults without Neurological Conditions for Camera-Engaged and Task-Engaged Visual Scenes

ERIC Educational Resources Information Center

Thiessen, Amber; Beukelman, David; Hux, Karen; Longenecker, Maria

2016-01-01

Purpose: The purpose of the study was to compare the visual attention patterns of adults with aphasia and adults without neurological conditions when viewing visual scenes with 2 types of engagement. Method: Eye-tracking technology was used to measure the visual attention patterns of 10 adults with aphasia and 10 adults without neurological…

Attention modulates perception of visual space

PubMed Central

Zhou, Liu; Deng, Chenglong; Ooi, Teng Leng; He, Zijiang J.

2017-01-01

Attention readily facilitates the detection and discrimination of objects, but it is not known whether it helps to form the vast volume of visual space that contains the objects and where actions are implemented. Conventional wisdom suggests not, given the effortless ease with which we perceive three-dimensional (3D) scenes on opening our eyes. Here, we show evidence to the contrary. In Experiment 1, the observer judged the location of a briefly presented target, placed either on the textured ground or ceiling surface. Judged location was more accurate for a target on the ground, provided that the ground was visible and that the observer directed attention to the lower visual field, not the upper field. This reveals that attention facilitates space perception with reference to the ground. Experiment 2 showed that judged location of a target in mid-air, with both ground and ceiling surfaces present, was more accurate when the observer directed their attention to the lower visual field; this indicates that the attention effect extends to visual space above the ground. These findings underscore the role of attention in anchoring visual orientation in space, which is arguably a primal event that enhances one’s ability to interact with objects and surface layouts within the visual space. The fact that the effect of attention was contingent on the ground being visible suggests that our terrestrial visual system is best served by its ecological niche. PMID:29177198

Automatic Guidance of Visual Attention from Verbal Working Memory

ERIC Educational Resources Information Center

Soto, David; Humphreys, Glyn W.

2007-01-01

Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize,…

Visual Spatial Attention to Multiple Locations At Once: The Jury Is Still Out

ERIC Educational Resources Information Center

Jans, Bert; Peters, Judith C.; De Weerd, Peter

2010-01-01

Although in traditional attention research the focus of visual spatial attention has been considered as indivisible, many studies in the last 15 years have claimed the contrary. These studies suggest that humans can direct their attention simultaneously to multiple noncontiguous regions of the visual field upon mere instruction. The notion that…

Television Viewing at Home: Age Trends in Visual Attention and Time with TV.

ERIC Educational Resources Information Center

Anderson, Daniel R.; And Others

1986-01-01

Decribes age trends in television viewing time and visual attention of children and adults videotaped in their homes for 10-day periods. Shows that the increase in visual attention to television during the preschool years is consistent with the theory that television program comprehensibility is a major determinant of attention in young children.…

The Tölz Temporal Topography Study: mapping the visual field across the life span. Part II: cognitive factors shaping visual field maps.

PubMed

Poggel, Dorothe A; Treutwein, Bernhard; Calmanti, Claudia; Strasburger, Hans

2012-08-01

Part I described the topography of visual performance over the life span. Performance decline was explained only partly by deterioration of the optical apparatus. Part II therefore examines the influence of higher visual and cognitive functions. Visual field maps for 95 healthy observers of static perimetry, double-pulse resolution (DPR), reaction times, and contrast thresholds, were correlated with measures of visual attention (alertness, divided attention, spatial cueing), visual search, and the size of the attention focus. Correlations with the attentional variables were substantial, particularly for variables of temporal processing. DPR thresholds depended on the size of the attention focus. The extraction of cognitive variables from the correlations between topographical variables and participant age substantially reduced those correlations. There is a systematic top-down influence on the aging of visual functions, particularly of temporal variables, that largely explains performance decline and the change of the topography over the life span.

Vision in Flies: Measuring the Attention Span

PubMed Central

Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

2016-01-01

A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s. PMID:26848852

Vision in Flies: Measuring the Attention Span.

PubMed

Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

2016-01-01

A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

Guidance of attention by information held in working memory.

PubMed

Calleja, Marissa Ortiz; Rich, Anina N

2013-05-01

Information held in working memory (WM) can guide attention during visual search. The authors of recent studies have interpreted the effect of holding verbal labels in WM as guidance of visual attention by semantic information. In a series of experiments, we tested how attention is influenced by visual features versus category-level information about complex objects held in WM. Participants either memorized an object's image or its category. While holding this information in memory, they searched for a target in a four-object search display. On exact-match trials, the memorized item reappeared as a distractor in the search display. On category-match trials, another exemplar of the memorized item appeared as a distractor. On neutral trials, none of the distractors were related to the memorized object. We found attentional guidance in visual search on both exact-match and category-match trials in Experiment 1, in which the exemplars were visually similar. When we controlled for visual similarity among the exemplars by using four possible exemplars (Exp. 2) or by using two exemplars rated as being visually dissimilar (Exp. 3), we found attentional guidance only on exact-match trials when participants memorized the object's image. The same pattern of results held when the target was invariant (Exps. 2-3) and when the target was defined semantically and varied in visual features (Exp. 4). The findings of these experiments suggest that attentional guidance by WM requires active visual information.

Intensive video gaming improves encoding speed to visual short-term memory in young male adults.

PubMed

Wilms, Inge L; Petersen, Anders; Vangkilde, Signe

2013-01-01

The purpose of this study was to measure the effect of action video gaming on central elements of visual attention using Bundesen's (1990) Theory of Visual Attention. To examine the cognitive impact of action video gaming, we tested basic functions of visual attention in 42 young male adults. Participants were divided into three groups depending on the amount of time spent playing action video games: non-players (<2h/month, N=12), casual players (4-8h/month, N=10), and experienced players (>15h/month, N=20). All participants were tested in three tasks which tap central functions of visual attention and short-term memory: a test based on the Theory of Visual Attention (TVA), an enumeration test and finally the Attentional Network Test (ANT). The results show that action video gaming does not seem to impact the capacity of visual short-term memory. However, playing action video games does seem to improve the encoding speed of visual information into visual short-term memory and the improvement does seem to depend on the time devoted to gaming. This suggests that intense action video gaming improves basic attentional functioning and that this improvement generalizes into other activities. The implications of these findings for cognitive rehabilitation training are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Cholinergic enhancement of visual attention and neural oscillations in the human brain.

PubMed

Bauer, Markus; Kluge, Christian; Bach, Dominik; Bradbury, David; Heinze, Hans Jochen; Dolan, Raymond J; Driver, Jon

2012-03-06

Cognitive processes such as visual perception and selective attention induce specific patterns of brain oscillations. The neurochemical bases of these spectral changes in neural activity are largely unknown, but neuromodulators are thought to regulate processing. The cholinergic system is linked to attentional function in vivo, whereas separate in vitro studies show that cholinergic agonists induce high-frequency oscillations in slice preparations. This has led to theoretical proposals that cholinergic enhancement of visual attention might operate via gamma oscillations in visual cortex, although low-frequency alpha/beta modulation may also play a key role. Here we used MEG to record cortical oscillations in the context of administration of a cholinergic agonist (physostigmine) during a spatial visual attention task in humans. This cholinergic agonist enhanced spatial attention effects on low-frequency alpha/beta oscillations in visual cortex, an effect correlating with a drug-induced speeding of performance. By contrast, the cholinergic agonist did not alter high-frequency gamma oscillations in visual cortex. Thus, our findings show that cholinergic neuromodulation enhances attentional selection via an impact on oscillatory synchrony in visual cortex, for low rather than high frequencies. We discuss this dissociation between high- and low-frequency oscillations in relation to proposals that lower-frequency oscillations are generated by feedback pathways within visual cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

Eye movements and attention: The role of pre-saccadic shifts of attention in perception, memory and the control of saccades

PubMed Central

Gersch, Timothy M.; Schnitzer, Brian S.; Dosher, Barbara A.; Kowler, Eileen

2012-01-01

Saccadic eye movements and perceptual attention work in a coordinated fashion to allow selection of the objects, features or regions with the greatest momentary need for limited visual processing resources. This study investigates perceptual characteristics of pre-saccadic shifts of attention during a sequence of saccades using the visual manipulations employed to study mechanisms of attention during maintained fixation. The first part of this paper reviews studies of the connections between saccades and attention, and their significance for both saccadic control and perception. The second part presents three experiments that examine the effects of pre-saccadic shifts of attention on vision during sequences of saccades. Perceptual enhancements at the saccadic goal location relative to non-goal locations were found across a range of stimulus contrasts, with either perceptual discrimination or detection tasks, with either single or multiple perceptual targets, and regardless of the presence of external noise. The results show that the preparation of saccades can evoke a variety of attentional effects, including attentionally-mediated changes in the strength of perceptual representations, selection of targets for encoding in visual memory, exclusion of external noise, or changes in the levels of internal visual noise. The visual changes evoked by saccadic planning make it possible for the visual system to effectively use saccadic eye movements to explore the visual environment. PMID:22809798

Focused and divided attention abilities in the acute phase of recovery from moderate to severe traumatic brain injury.

PubMed

Robertson, Kayela; Schmitter-Edgecombe, Maureen

2017-01-01

Impairments in attention following traumatic brain injury (TBI) can significantly impact recovery and rehabilitation effectiveness. This study investigated the multi-faceted construct of selective attention following TBI, highlighting the differences on visual nonsearch (focused attention) and search (divided attention) tasks. Participants were 30 individuals with moderate to severe TBI who were tested acutely (i.e. following emergence from PTA) and 30 age- and education-matched controls. Participants were presented with visual displays that contained either two or eight items. In the focused attention, nonsearch condition, the location of the target (if present) was cued with a peripheral arrow prior to presentation of the visual displays. In the divided attention, search condition, no spatial cue was provided prior to presentation of the visual displays. The results revealed intact focused, nonsearch, attention abilities in the acute phase of TBI recovery. In contrast, when no spatial cue was provided (divided attention condition), participants with TBI demonstrated slower visual search compared to the control group. The results of this study suggest that capitalizing on intact focused attention abilities by allocating attention during cognitively demanding tasks may help to reduce mental workload and improve rehabilitation effectiveness.

Visual attention and academic performance in children with developmental disabilities and behavioural attention deficits.

PubMed

Kirk, Hannah E; Gray, Kylie; Riby, Deborah M; Taffe, John; Cornish, Kim M

2017-11-01

Despite well-documented attention deficits in children with intellectual and developmental disabilities (IDD), distinctions across types of attention problems and their association with academic attainment has not been fully explored. This study examines visual attention capacities and inattentive/hyperactive behaviours in 77 children aged 4 to 11 years with IDD and elevated behavioural attention difficulties. Children with autism spectrum disorder (ASD; n = 23), Down syndrome (DS; n = 22), and non-specific intellectual disability (NSID; n = 32) completed computerized visual search and vigilance paradigms. In addition, parents and teachers completed rating scales of inattention and hyperactivity. Concurrent associations between attention abilities and early literacy and numeracy skills were also examined. Children completed measures of receptive vocabulary, phonological abilities and cardinality skills. As expected, the results indicated that all groups had relatively comparable levels of inattentive/hyperactive behaviours as rated by parents and teachers. However, the extent of visual attention deficits varied as a result of group; namely children with DS had poorer visual search and vigilance abilities than children with ASD and NSID. Further, significant associations between visual attention difficulties and poorer literacy and numeracy skills were observed, regardless of group. Collectively the findings demonstrate that in children with IDD who present with homogenous behavioural attention difficulties, at the cognitive level, subtle profiles of attentional problems can be delineated. © 2016 John Wiley & Sons Ltd.

Is attentional prioritisation of infant faces unique in humans?: Comparative demonstrations by modified dot-probe task in monkeys.

PubMed

Koda, Hiroki; Sato, Anna; Kato, Akemi

2013-09-01

Humans innately perceive infantile features as cute. The ethologist Konrad Lorenz proposed that the infantile features of mammals and birds, known as the baby schema (kindchenschema), motivate caretaking behaviour. As biologically relevant stimuli, newborns are likely to be processed specially in terms of visual attention, perception, and cognition. Recent demonstrations on human participants have shown visual attentional prioritisation to newborn faces (i.e., newborn faces capture visual attention). Although characteristics equivalent to those found in the faces of human infants are found in nonhuman primates, attentional capture by newborn faces has not been tested in nonhuman primates. We examined whether conspecific newborn faces captured the visual attention of two Japanese monkeys using a target-detection task based on dot-probe tasks commonly used in human visual attention studies. Although visual cues enhanced target detection in subject monkeys, our results, unlike those for humans, showed no evidence of an attentional prioritisation for newborn faces by monkeys. Our demonstrations showed the validity of dot-probe task for visual attention studies in monkeys and propose a novel approach to bridge the gap between human and nonhuman primate social cognition research. This suggests that attentional capture by newborn faces is not common to macaques, but it is unclear if nursing experiences influence their perception and recognition of infantile appraisal stimuli. We need additional comparative studies to reveal the evolutionary origins of baby-schema perception and recognition. Copyright © 2013 Elsevier B.V. All rights reserved.

Focused and shifting attention in children with heavy prenatal alcohol exposure.

PubMed

Mattson, Sarah N; Calarco, Katherine E; Lang, Aimée R

2006-05-01

Attention deficits are a hallmark of the teratogenic effects of alcohol. However, characterization of these deficits remains inconclusive. Children with heavy prenatal alcohol exposure and nonexposed controls were evaluated using a paradigm consisting of three conditions: visual focus, auditory focus, and auditory-visual shift of attention. For the focus conditions, participants responded manually to visual or auditory targets. For the shift condition, participants alternated responses between visual targets and auditory targets. For the visual focus condition, alcohol-exposed children had lower accuracy and slower reaction time for all intertarget intervals (ITIs), while on the auditory focus condition, alcohol-exposed children were less accurate but displayed slower reaction time only on the longest ITI. Finally, for the shift condition, the alcohol-exposed group was accurate but had slowed reaction times. These results indicate that children with heavy prenatal alcohol exposure have pervasive deficits in visual focused attention and deficits in maintaining auditory attention over time. However, no deficits were noted in the ability to disengage and reengage attention when required to shift attention between visual and auditory stimuli, although reaction times to shift were slower. Copyright (c) 2006 APA, all rights reserved.

Visual Attention Model Based on Statistical Properties of Neuron Responses

PubMed Central

Duan, Haibin; Wang, Xiaohua

2015-01-01

Visual attention is a mechanism of the visual system that can select relevant objects from a specific scene. Interactions among neurons in multiple cortical areas are considered to be involved in attentional allocation. However, the characteristics of the encoded features and neuron responses in those attention related cortices are indefinite. Therefore, further investigations carried out in this study aim at demonstrating that unusual regions arousing more attention generally cause particular neuron responses. We suppose that visual saliency is obtained on the basis of neuron responses to contexts in natural scenes. A bottom-up visual attention model is proposed based on the self-information of neuron responses to test and verify the hypothesis. Four different color spaces are adopted and a novel entropy-based combination scheme is designed to make full use of color information. Valuable regions are highlighted while redundant backgrounds are suppressed in the saliency maps obtained by the proposed model. Comparative results reveal that the proposed model outperforms several state-of-the-art models. This study provides insights into the neuron responses based saliency detection and may underlie the neural mechanism of early visual cortices for bottom-up visual attention. PMID:25747859

The effect of search condition and advertising type on visual attention to Internet advertising.

PubMed

Kim, Gho; Lee, Jang-Han

2011-05-01

This research was conducted to examine the level of consumers' visual attention to Internet advertising. It was predicted that consumers' search type would influence visual attention to advertising. Specifically, it was predicted that more attention to advertising would be attracted in the exploratory search condition than in the goal-directed search condition. It was also predicted that there would be a difference in visual attention depending on the advertisement type (advertising type: text vs. pictorial advertising). An eye tracker was used for measurement. Results revealed that search condition and advertising type influenced advertising effectiveness.

Sympathetic ophthalmia: incidence of ocular complications and vision loss in the sympathizing eye.

PubMed

Galor, Anat; Davis, Janet L; Flynn, Harry W; Feuer, William J; Dubovy, Sander R; Setlur, Vikram; Kesen, Muge R; Goldstein, Debra A; Tessler, Howard H; Ganelis, Irina Bykhovskaya; Jabs, Douglas A; Thorne, Jennifer E

2009-11-01

To report the frequency on presentation and subsequent incidence of ocular complications and vision loss in patients with sympathetic ophthalmia (SO) and to describe factors associated with decreased vision in the sympathizing eye. Multicenter retrospective case series. Three academic tertiary care uveitis clinics. Eighty-five patients with SO from 1976 to 2006. Review of existing medical records. Incident visual acuity (VA) loss to 20/50 or worse and 20/200 or worse and the median acuity over time. Twenty-six percent of patients with SO presented with a VA of 20/200 or worse in their sympathizing eye. Further development of vision loss to 20/200 or worse occurred at the rate of 10% per person-year (PY). Ocular complications were seen in the sympathizing eye in 47% of patients at presentation; further development of new complications occurred at the rate of 40%/PY. The ocular complications most often associated with decreased vision were cataract and optic nerve abnormality. Exudative retinal detachment and active intraocular inflammation were significantly associated with poorer VA in the sympathizing eye. The benefits of corticosteroids were indirectly demonstrated as their use led to more rapid disease inactivation. Fifty-nine percent of patients maintained a VA of better than 20/50 in their sympathizing eye; and 75% maintained a VA of better than 20/200. Although ocular complications were seen in many sympathizing eyes with SO, most patients maintained functional VA. The presence of an exudative retinal detachment and active intraocular inflammation correlated with poorer vision in the sympathizing eye.

Relative sensitivity of clinical tests to hydrophilic lens-induced corneal thickness changes.

PubMed

Elliott, D B; Fonn, D; Flanagan, J; Doughty, M

1993-12-01

The relative sensitivity of the van den Berg Straylightmeter, slitlamp biomicroscopy, a modified optical pachometer, Bailey-Lovie logMAR visual acuity (VA), and two glare tests (The Brightness Acuity Tester used with 10% contrast VA and Pelli-Robson contrast sensitivity) to hydrophilic contact lens-induced edema was assessed in 19 subjects (mean age 25.9 +/- 4.5 years). After baseline assessments, subjects wore thick hydrogel lenses on one eye which was patched tightly for 3 h. Assessments were repeated at frequent intervals after lens removal to assess recovery. None of the pachometer measurements returned to baseline within the 2-h monitoring period, although the majority were within 2% of baseline corneal thickness. The average time for the Straylightmeter scores to recover to baseline values after the lens removal was 90 min, which was similar to the time when visible edema at the slitlamp disappeared. The average time for return to baseline of logMAR VA and the two glare tests was consistently two to three times shorter than the time for the Straylightmeter score. The Straylightmeter therefore provided assessments of corneal edema similar to slitlamp examination and was more sensitive than VA or glare testing.

Precision Medicine for CRC Patients in the Veteran Population: State-of-the-Art, Challenges and Research Directions.

PubMed

Mohapatra, Shyam S; Batra, Surinder K; Bharadwaj, Srinivas; Bouvet, Michael; Cosman, Bard; Goel, Ajay; Jogunoori, Wilma; Kelley, Michael J; Mishra, Lopa; Mishra, Bibhuti; Mohapatra, Subhra; Patel, Bhaumik; Pisegna, Joseph R; Raufman, Jean-Pierre; Rao, Shuyun; Roy, Hemant; Scheuner, Maren; Singh, Satish; Vidyarthi, Gitanjali; White, Jon

2018-05-01

Colorectal cancer (CRC) accounts for ~9% of all cancers in the Veteran population, a fact which has focused a great deal of the attention of the VA's research and development efforts. A field-based meeting of CRC experts was convened to discuss both challenges and opportunities in precision medicine for CRC. This group, designated as the VA Colorectal Cancer Cell-genomics Consortium (VA4C), discussed advances in CRC biology, biomarkers, and imaging for early detection and prevention. There was also a discussion of precision treatment involving fluorescence-guided surgery, targeted chemotherapies and immunotherapies, and personalized cancer treatment approaches. The overarching goal was to identify modalities that might ultimately lead to personalized cancer diagnosis and treatment. This review summarizes the findings of this VA field-based meeting, in which much of the current knowledge on CRC prescreening and treatment was discussed. It was concluded that there is a need and an opportunity to identify new targets for both the prevention of CRC and the development of effective therapies for advanced disease. Also, developing methods integrating genomic testing with tumoroid-based clinical drug response might lead to more accurate diagnosis and prognostication and more effective personalized treatment of CRC.

Vertically aligned carbon nanotube electrodes for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Welna, Daniel T.; Qu, Liangti; Taylor, Barney E.; Dai, Liming; Durstock, Michael F.

As portable electronics become more advanced and alternative energy demands become more prevalent, the development of advanced energy storage technologies is becoming ever more critical in today's society. In order to develop higher power and energy density batteries, innovative electrode materials that provide increased storage capacity, greater rate capabilities, and good cyclability must be developed. Nanostructured materials are gaining increased attention because of their potential to mitigate current electrode limitations. Here we report on the use of vertically aligned multi-walled carbon nanotubes (VA-MWNTs) as the active electrode material in lithium-ion batteries. At low specific currents, these VA-MWNTs have shown high reversible specific capacities (up to 782 mAh g -1 at 57 mA g -1). This value is twice that of the theoretical maximum for graphite and ten times more than their non-aligned equivalent. Interestingly, at very high discharge rates, the VA-MWNT electrodes retain a moderate specific capacity due to their aligned nature (166 mAh g -1 at 26 A g -1). These results suggest that VA-MWNTs are good candidates for lithium-ion battery electrodes which require high rate capability and capacity.

Sustained visual-spatial attention produces costs and benefits in response time and evoked neural activity.

PubMed

Mangun, G R; Buck, L A

1998-03-01

This study investigated the simple reaction time (RT) and event-related potential (ERP) correlates of biasing attention towards a location in the visual field. RTs and ERPs were recorded to stimuli flashed randomly and with equal probability to the left and right visual hemifields in the three blocked, covert attention conditions: (i) attention divided equally to left and right hemifield locations; (ii) attention biased towards the left location; or (iii) attention biased towards the right location. Attention was biased towards left or right by instructions to the subjects, and responses were required to all stimuli. Relative to the divided attention condition, RTs were significantly faster for targets occurring where more attention was allocated (benefits), and slower to targets where less attention was allocated (costs). The early P1 (100-140 msec) component over the lateral occipital scalp regions showed attentional benefits. There were no amplitude modulations of the occipital N1 (125-180 msec) component with attention. Between 200 and 500 msec latency, a late positive deflection (LPD) showed both attentional costs and benefits. The behavioral findings show that when sufficiently induced to bias attention, human observers demonstrate RT benefits as well as costs. The corresponding P1 benefits suggest that the RT benefits of spatial attention may arise as the result of modulations of visual information processing in the extrastriate visual cortex.

Global motion compensated visual attention-based video watermarking

NASA Astrophysics Data System (ADS)

Oakes, Matthew; Bhowmik, Deepayan; Abhayaratne, Charith

2016-11-01

Imperceptibility and robustness are two key but complementary requirements of any watermarking algorithm. Low-strength watermarking yields high imperceptibility but exhibits poor robustness. High-strength watermarking schemes achieve good robustness but often suffer from embedding distortions resulting in poor visual quality in host media. This paper proposes a unique video watermarking algorithm that offers a fine balance between imperceptibility and robustness using motion compensated wavelet-based visual attention model (VAM). The proposed VAM includes spatial cues for visual saliency as well as temporal cues. The spatial modeling uses the spatial wavelet coefficients while the temporal modeling accounts for both local and global motion to arrive at the spatiotemporal VAM for video. The model is then used to develop a video watermarking algorithm, where a two-level watermarking weighting parameter map is generated from the VAM saliency maps using the saliency model and data are embedded into the host image according to the visual attentiveness of each region. By avoiding higher strength watermarking in the visually attentive region, the resulting watermarked video achieves high perceived visual quality while preserving high robustness. The proposed VAM outperforms the state-of-the-art video visual attention methods in joint saliency detection and low computational complexity performance. For the same embedding distortion, the proposed visual attention-based watermarking achieves up to 39% (nonblind) and 22% (blind) improvement in robustness against H.264/AVC compression, compared to existing watermarking methodology that does not use the VAM. The proposed visual attention-based video watermarking results in visual quality similar to that of low-strength watermarking and a robustness similar to those of high-strength watermarking.

Contingent capture of involuntary visual spatial attention does not differ between normally hearing children and proficient cochlear implant users.

PubMed

Kamke, Marc R; Van Luyn, Jeanette; Constantinescu, Gabriella; Harris, Jill

2014-01-01

Evidence suggests that deafness-induced changes in visual perception, cognition and attention may compensate for a hearing loss. Such alterations, however, may also negatively influence adaptation to a cochlear implant. This study investigated whether involuntary attentional capture by salient visual stimuli is altered in children who use a cochlear implant. Thirteen experienced implant users (aged 8-16 years) and age-matched normally hearing children were presented with a rapid sequence of simultaneous visual and auditory events. Participants were tasked with detecting numbers presented in a specified color and identifying a change in the tonal frequency whilst ignoring irrelevant visual distractors. Compared to visual distractors that did not possess the target-defining characteristic, target-colored distractors were associated with a decrement in visual performance (response time and accuracy), demonstrating a contingent capture of involuntary attention. Visual distractors did not, however, impair auditory task performance. Importantly, detection performance for the visual and auditory targets did not differ between the groups. These results suggest that proficient cochlear implant users demonstrate normal capture of visuospatial attention by stimuli that match top-down control settings.

Targeting Behavioral Symptoms and Functional Decline in Dementia: A Randomized Clinical Trial.

PubMed

Gitlin, Laura N; Arthur, Paul; Piersol, Catherine; Hessels, Virginia; Wu, Samuel S; Dai, Yunfeng; Mann, William C

2018-02-01

Dementia-related behavioral symptoms and functional dependence result in poor quality of life for persons with dementia and their caregivers. The goal was to determine whether a home-based activity program (Tailored Activity Program; TAP-VA) would reduce behavioral symptoms and functional dependence of veterans with dementia and caregiver burden. Single-blind (interviewer), parallel, randomized, controlled trial (Clinicaltrials.gov: NCT01357564). Veteran's homes. Veterans with dementia and their family caregivers (N = 160 dyads). Dyads in TAP-VA underwent 8 sessions with occupational therapists to customize activities to the interests and abilities of the veterans and educate their caregivers about dementia and use of customized activity. Caregivers assigned to attention control received up to 8 telephone-based dementia education sessions with a research team member. Primary outcomes included number of behaviors and frequency of their occurrence multiplied by severity of occurrence; secondary outcomes were functional dependence, pain, emotional well-being, caregiver burden (time spent caregiving, upset with behaviors) and affect at 4 (primary endpoint) and 8 months. Of 160 dyads (n = 76 TAP-VA; n = 84 control), 111 completed 4-month interviews (n = 51 TAP-VA; n = 60 control), and 103 completed 8-month interviews (n = 50 TAP-VA; n = 53 control). At 4 months, compared to controls, the TAP-VA group showed reductions in number (difference in mean change from baseline = -0.68, 95% CI = -1.23 to -0.13) and frequency by severity (-24.3, 95% CI = -45.6 to -3.1) of behavioral symptoms, number of activities needing assistance with (-0.80, 95% CI = -1.41 to -0.20), functional dependence level (4.09, 95% CI = 1.06, 7.13), and pain (-1.18, 95% CI = -2.10 to -0.26). Caregivers of veterans in TAP-VA reported less behavior-related distress. Benefits did not extend to 8 months. TAP-VA had positive immediate effects and no adverse events. Because TAP-VA reduces behavioral symptoms, slows functional dependence, and alleviates pain and caregiver distress, it is a viable treatment option for families. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Splitting attention across the two visual fields in visual short-term memory.

PubMed

Delvenne, Jean-Francois; Holt, Jessica L

2012-02-01

Humans have the ability to attentionally select the most relevant visual information from their extrapersonal world and to retain it in a temporary buffer, known as visual short-term memory (VSTM). Research suggests that at least two non-contiguous items can be selected simultaneously when they are distributed across the two visual hemifields. In two experiments, we show that attention can also be split between the left and right sides of internal representations held in VSTM. Participants were asked to remember several colors, while cues presented during the delay instructed them to orient their attention to a subset of memorized colors. Experiment 1 revealed that orienting attention to one or two colors strengthened equally participants' memory for those colors, but only when they were from separate hemifields. Experiment 2 showed that in the absence of attentional cues the distribution of the items in the visual field per se had no effect on memory. These findings strongly suggest the existence of independent attentional resources in the two hemifields for selecting and/or consolidating information in VSTM. Copyright © 2011 Elsevier B.V. All rights reserved.

Parameter-Based Assessment of Disturbed and Intact Components of Visual Attention in Children with Developmental Dyslexia

ERIC Educational Resources Information Center

Bogon, Johanna; Finke, Kathrin; Schulte-Körne, Gerd; Müller, Hermann J.; Schneider, Werner X.; Stenneken, Prisca

2014-01-01

People with developmental dyslexia (DD) have been shown to be impaired in tasks that require the processing of multiple visual elements in parallel. It has been suggested that this deficit originates from disturbed visual attentional functions. The parameter-based assessment of visual attention based on Bundesen's (1990) theory of visual…

National Dam Safety Program. Pedlar River Dam (Inventory Number VA 00905), James River Basin, Amherst County, Virginia. Phase I Inspection Report

DTIC Science & Technology

1980-06-01

Controlling Office) I5. SECURITY CLASS. (of this report) Unclassified 15a. DECL ASSI FICATION/DOWN GRADING SCHEDULE 16 . DISTRIBUTION STATEMENT (of this...pose hazards to human life or property . The assessment of the general conditions of the dam is based upon available data and visual inspections...human life or property . The assessment of the general condition of the dam is based upon available data and visual inspections. Detailed in- vestigation

The Influence of Stimulus Material on Attention and Performance in the Visual Expectation Paradigm: A Longitudinal Study with 3- And 6-Month-Old Infants

ERIC Educational Resources Information Center

Teubert, Manuel; Lohaus, Arnold; Fassbender, Ina; Vierhaus, Marc; Spangler, Sibylle; Borchert, Sonja; Freitag, Claudia; Goertz, Claudia; Graf, Frauke; Gudi, Helene; Kolling, Thorsten; Lamm, Bettina; Keller, Heidi; Knopf, Monika; Schwarzer, Gudrun

2012-01-01

This longitudinal study examined the influence of stimulus material on attention and expectation learning in the visual expectation paradigm. Female faces were used as attention-attracting stimuli, and non-meaningful visual stimuli of comparable complexity (Greebles) were used as low attention-attracting stimuli. Expectation learning performance…

The Role of Target-Distractor Relationships in Guiding Attention and the Eyes in Visual Search

ERIC Educational Resources Information Center

Becker, Stefanie I.

2010-01-01

Current models of visual search assume that visual attention can be guided by tuning attention toward specific feature values (e.g., particular size, color) or by inhibiting the features of the irrelevant nontargets. The present study demonstrates that attention and eye movements can also be guided by a relational specification of how the target…

Attention biases visual activity in visual short-term memory.

PubMed

Kuo, Bo-Cheng; Stokes, Mark G; Murray, Alexandra M; Nobre, Anna Christina

2014-07-01

In the current study, we tested whether representations in visual STM (VSTM) can be biased via top-down attentional modulation of visual activity in retinotopically specific locations. We manipulated attention using retrospective cues presented during the retention interval of a VSTM task. Retrospective cues triggered activity in a large-scale network implicated in attentional control and led to retinotopically specific modulation of activity in early visual areas V1-V4. Importantly, shifts of attention during VSTM maintenance were associated with changes in functional connectivity between pFC and retinotopic regions within V4. Our findings provide new insights into top-down control mechanisms that modulate VSTM representations for flexible and goal-directed maintenance of the most relevant memoranda.

Association of blood antioxidants status with visual and auditory sustained attention.

PubMed

Shiraseb, Farideh; Siassi, Fereydoun; Sotoudeh, Gity; Qorbani, Mostafa; Rostami, Reza; Sadeghi-Firoozabadi, Vahid; Narmaki, Elham

2015-01-01

A low antioxidants status has been shown to result in oxidative stress and cognitive impairment. Because antioxidants can protect the nervous system, it is expected that a better blood antioxidant status might be related to sustained attention. However, the relationship between the blood antioxidant status and visual and auditory sustained attention has not been investigated. The aim of this study was to evaluate the association of fruits and vegetables intake and the blood antioxidant status with visual and auditory sustained attention in women. This cross-sectional study was performed on 400 healthy women (20-50 years) who attended the sports clubs of Tehran Municipality. Sustained attention was evaluated based on the Integrated Visual and Auditory Continuous Performance Test using the Integrated Visual and Auditory (IVA) software. The 24-hour food recall questionnaire was used for estimating fruits and vegetables intake. Serum total antioxidant capacity (TAC), and erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured in 90 participants. After adjusting for energy intake, age, body mass index (BMI), years of education and physical activity, higher reported fruits, and vegetables intake was associated with better visual and auditory sustained attention (P < 0.001). A high intake of some subgroups of fruits and vegetables (i.e. berries, cruciferous vegetables, green leafy vegetables, and other vegetables) was also associated with better sustained attention (P < 0.02). Serum TAC, and erythrocyte SOD and GPx activities increased with the increase in the tertiles of visual and auditory sustained attention after adjusting for age, years of education, physical activity, energy, BMI, and caffeine intake (P < 0.05). Improved visual and auditory sustained attention is associated with a better blood antioxidant status. Therefore, improvement of the antioxidant status through an appropriate dietary intake can possibly enhance sustained attention.

Short-term retention of visual information: Evidence in support of feature-based attention as an underlying mechanism.

PubMed

Sneve, Markus H; Sreenivasan, Kartik K; Alnæs, Dag; Endestad, Tor; Magnussen, Svein

2015-01-01

Retention of features in visual short-term memory (VSTM) involves maintenance of sensory traces in early visual cortex. However, the mechanism through which this is accomplished is not known. Here, we formulate specific hypotheses derived from studies on feature-based attention to test the prediction that visual cortex is recruited by attentional mechanisms during VSTM of low-level features. Functional magnetic resonance imaging (fMRI) of human visual areas revealed that neural populations coding for task-irrelevant feature information are suppressed during maintenance of detailed spatial frequency memory representations. The narrow spectral extent of this suppression agrees well with known effects of feature-based attention. Additionally, analyses of effective connectivity during maintenance between retinotopic areas in visual cortex show that the observed highlighting of task-relevant parts of the feature spectrum originates in V4, a visual area strongly connected with higher-level control regions and known to convey top-down influence to earlier visual areas during attentional tasks. In line with this property of V4 during attentional operations, we demonstrate that modulations of earlier visual areas during memory maintenance have behavioral consequences, and that these modulations are a result of influences from V4. Copyright © 2014 Elsevier Ltd. All rights reserved.

Components of working memory and visual selective attention.

PubMed

Burnham, Bryan R; Sabia, Matthew; Langan, Catherine

2014-02-01

Load theory (Lavie, N., Hirst, A., De Fockert, J. W., & Viding, E. [2004]. Load theory of selective attention and cognitive control. Journal of Experimental Psychology: General, 133, 339-354.) proposes that control of attention depends on the amount and type of load that is imposed by current processing. Specifically, perceptual load should lead to efficient distractor rejection, whereas working memory load (dual-task coordination) should hinder distractor rejection. Studies support load theory's prediction that working memory load will lead to larger distractor effects; however, these studies used secondary tasks that required only verbal working memory and the central executive. The present study examined which other working memory components (visual, spatial, and phonological) influence visual selective attention. Subjects completed an attentional capture task alone (single-task) or while engaged in a working memory task (dual-task). Results showed that along with the central executive, visual and spatial working memory influenced selective attention, but phonological working memory did not. Specifically, attentional capture was larger when visual or spatial working memory was loaded, but phonological working memory load did not affect attentional capture. The results are consistent with load theory and suggest specific components of working memory influence visual selective attention. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Asymmetrical brain activity induced by voluntary spatial attention depends on the visual hemifield: a functional near-infrared spectroscopy study.

PubMed

Harasawa, Masamitsu; Shioiri, Satoshi

2011-04-01

The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a previous psychophysical study, namely, the attentional resources for the left and right visual hemifields are distinct. Increasing the attentional load asymmetrically increased the brain activity. Increase in attentional load produced a greater increase in brain activity in the case of the left visual hemifield than in the case of the right visual hemifield. This asymmetry was observed in all the examined brain areas, including the right and left occipital and parietal cortices. These results suggest the existence of asymmetrical inhibitory interactions between the hemispheres and the presence of an extensive inhibitory network. Copyright © 2011 Elsevier Inc. All rights reserved.

Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

PubMed

Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

2015-11-01

In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

Intraoperative indocyanine green videoangiography for identification of pituitary adenomas using a microscopic transsphenoidal approach.

PubMed

Sandow, N; Klene, W; Elbelt, U; Strasburger, C J; Vajkoczy, P

2015-10-01

Initial successful surgical treatment of pituitary adenomas is crucial to reach long-term remission. Indocyanine green (ICG) videoangiography (VA) is well established in vascular neurosurgery nowadays and several reports described ICG application in brain tumor surgery. We designed this study to evaluate the feasibility of intravenous application of ICG and visualisation of a pituitary lesion via the fluorescence mode of the operation microscope. 22 patients with pituitary adenomas were treated with transsphenoidal microsurgery and were included in this study. Intraoperatively 25 mg ICG was administered intravenously and visualized via the fluorescence mode of the operation microscope (Pentero/Zeiss). 22 patients qualified for transsphenoidal surgery presenting with different clinical symptoms (13 patients with acromegaly, 6 with M. Cushing and 3 with other symptoms like vision disorder or dizziness) and identification of a pituitary lesion (21 of 22 patients) in preoperative MR-imaging (mean diameter: 9 mm; SD 3.6; 6 macroadenomas, 15 microadenomas, 1 MR-negative). In all 22 patients ICG VA was performed during surgery. No technical failures or adverse events after drug administration occurred. Visualization was optimal approximately 2.4 min after intravenous application. In all patients the adenoma could be detected via two different types of visualization: direct visualization by fluorophore emission versus indirect detection of the adenoma by a lower ICG fluorescence compared to the surrounding tissue. Our data show that intraoperative ICG VA can be a useful and easily applicable additional diagnostic tool for visualization of pituitary lesions using the microscopic approach.

Contrast visual acuity in patients with retinitis pigmentosa assessed by a contrast sensitivity tester.

PubMed

Oishi, Maho; Nakamura, Hajime; Hangai, Masanori; Oishi, Akio; Otani, Atsushi; Yoshimura, Nagahisa

2012-01-01

To assess contrast visual acuity (CVA) in patients with retinitis pigmentosa (RP) and compare the result with standard visual acuity (VA), retinal thickness, status of inner segment/outer segment junction, and central visual field. Thirty-nine eyes of 39 patients with RP and 39 eyes of 39 healthy individuals were studied. To see the difference in CVA between RP patients and normal controls, only subjects with standard VA of 1.0 (20/20) or better were included. This was a cross-sectional study. CVA in various light conditions was measured with CAT-2000 and was compared between patients and controls. CVA of patients was further analyzed for association with other parameters including foveal retinal thickness, outer nuclear layer thickness, the status of inner segment/outer segment junction measured with optical coherence tomography (OCT), and visual field mean deviation (MD) measured with Humphrey field analyzer 10-2 program. CVA impairment was evident in RP patients compared to controls (P < 0.01, in all measurement conditions). Multivariate analysis showed association of logarithm of the minimum angle of resolution (logMAR) with CVAs in several conditions. None of the OCT measurements was associated with CVA. When patients were divided into three groups based on MD, the most advanced group (MD worse than or equal to -20 dB) showed impairment of mesopic CVA (P < 0.05, under mesopic condition of 100% without glare, with glare, and 25% without glare). CVA impairment was confirmed in RP patients, especially in advanced cases. CVA measured with CAT-2000 may be a useful tool for assessing foveal function in RP patients.

An action video game for the treatment of amblyopia in children: A feasibility study.

PubMed

Gambacorta, Christina; Nahum, Mor; Vedamurthy, Indu; Bayliss, Jessica; Jordan, Josh; Bavelier, Daphne; Levi, Dennis M

2018-05-12

The gold-standard treatment for childhood amblyopia remains patching or penalizing the fellow eye, resulting in an average of about a one line (0.1 logMAR) improvement in visual acuity following ≈120 h of patching in children 3-8 years old. However, compliance with patching and other treatment options is often poor. In contrast, fast-paced action video games can be highly engaging, and have been shown to yield broad-based improvements in vision and attention in adult amblyopia. Here, we pilot-tested a custom-made action video game to treat children with amblyopia. Twenty-one (n = 21) children (mean age 9.95 ± 3.14 [se]) with unilateral amblyopia (n = 12 anisometropic and n = 9 strabismic) completed 20 h of game play either monocularly, with the fellow eye patched (n = 11), or dichoptically, with reduced contrast to the fellow eye (n = 10). Participants were assessed for visual acuity (VA), stereo acuity and reading speed at baseline, and following 10 and 20 h of play. Additional exploratory analyses examined improvements after 6-10 weeks of completion of training (follow-up). Following 20 h of training, VA improved, on average, by 0.14 logMAR (≈38%) for the dichoptic group and by 0.06 logMAR (≈15%) for the monocular group. Similarly, stereoacuity improved by 0.07 log arcsec (≈17%) following dichoptic training, and by 0.06 log arcsec (≈15%) following monocular training. Across both treatment groups, 7 of the 12 individuals with anisometropic amblyopia showed improvement in stereoacuity, whereas only 1 of the 9 strabismic individuals improved. Most improvements were largely retained at follow-up. Our feasibility study therefore suggests that the action video game approach may be used as an effective adjunct treatment for amblyopia in children, achieving results similar to those of the gold-standard treatment in shorter duration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cross-modal attention influences auditory contrast sensitivity: Decreasing visual load improves auditory thresholds for amplitude- and frequency-modulated sounds.

PubMed

Ciaramitaro, Vivian M; Chow, Hiu Mei; Eglington, Luke G

2017-03-01

We used a cross-modal dual task to examine how changing visual-task demands influenced auditory processing, namely auditory thresholds for amplitude- and frequency-modulated sounds. Observers had to attend to two consecutive intervals of sounds and report which interval contained the auditory stimulus that was modulated in amplitude (Experiment 1) or frequency (Experiment 2). During auditory-stimulus presentation, observers simultaneously attended to a rapid sequential visual presentation-two consecutive intervals of streams of visual letters-and had to report which interval contained a particular color (low load, demanding less attentional resources) or, in separate blocks of trials, which interval contained more of a target letter (high load, demanding more attentional resources). We hypothesized that if attention is a shared resource across vision and audition, an easier visual task should free up more attentional resources for auditory processing on an unrelated task, hence improving auditory thresholds. Auditory detection thresholds were lower-that is, auditory sensitivity was improved-for both amplitude- and frequency-modulated sounds when observers engaged in a less demanding (compared to a more demanding) visual task. In accord with previous work, our findings suggest that visual-task demands can influence the processing of auditory information on an unrelated concurrent task, providing support for shared attentional resources. More importantly, our results suggest that attending to information in a different modality, cross-modal attention, can influence basic auditory contrast sensitivity functions, highlighting potential similarities between basic mechanisms for visual and auditory attention.

Multiple Sensory-Motor Pathways Lead to Coordinated Visual Attention

PubMed Central

Yu, Chen; Smith, Linda B.

2016-01-01

Joint attention has been extensively studied in the developmental literature because of overwhelming evidence that the ability to socially coordinate visual attention to an object is essential to healthy developmental outcomes, including language learning. The goal of the present study is to understand the complex system of sensory-motor behaviors that may underlie the establishment of joint attention between parents and toddlers. In an experimental task, parents and toddlers played together with multiple toys. We objectively measured joint attention – and the sensory-motor behaviors that underlie it – using a dual head-mounted eye-tracking system and frame-by-frame coding of manual actions. By tracking the momentary visual fixations and hand actions of each participant, we precisely determined just how often they fixated on the same object at the same time, the visual behaviors that preceded joint attention, and manual behaviors that preceded and co-occurred with joint attention. We found that multiple sequential sensory-motor patterns lead to joint attention. In addition, there are developmental changes in this multi-pathway system evidenced as variations in strength among multiple routes. We propose that coordinated visual attention between parents and toddlers is primarily a sensory-motor behavior. Skill in achieving coordinated visual attention in social settings – like skills in other sensory-motor domains – emerges from multiple pathways to the same functional end. PMID:27016038

Multiple Sensory-Motor Pathways Lead to Coordinated Visual Attention.

PubMed

Yu, Chen; Smith, Linda B

2017-02-01

Joint attention has been extensively studied in the developmental literature because of overwhelming evidence that the ability to socially coordinate visual attention to an object is essential to healthy developmental outcomes, including language learning. The goal of this study was to understand the complex system of sensory-motor behaviors that may underlie the establishment of joint attention between parents and toddlers. In an experimental task, parents and toddlers played together with multiple toys. We objectively measured joint attention-and the sensory-motor behaviors that underlie it-using a dual head-mounted eye-tracking system and frame-by-frame coding of manual actions. By tracking the momentary visual fixations and hand actions of each participant, we precisely determined just how often they fixated on the same object at the same time, the visual behaviors that preceded joint attention and manual behaviors that preceded and co-occurred with joint attention. We found that multiple sequential sensory-motor patterns lead to joint attention. In addition, there are developmental changes in this multi-pathway system evidenced as variations in strength among multiple routes. We propose that coordinated visual attention between parents and toddlers is primarily a sensory-motor behavior. Skill in achieving coordinated visual attention in social settings-like skills in other sensory-motor domains-emerges from multiple pathways to the same functional end. Copyright © 2016 Cognitive Science Society, Inc.

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Visual Spatial Attention Training Improve Spatial Attention and Motor Control for Unilateral Neglect Patients.

PubMed

Wang, Wei; Ji, Xiangtong; Ni, Jun; Ye, Qian; Zhang, Sicong; Chen, Wenli; Bian, Rong; Yu, Cui; Zhang, Wenting; Shen, Guangyu; Machado, Sergio; Yuan, Tifei; Shan, Chunlei

2015-01-01

To compare the effect of visual spatial training on the spatial attention to that on motor control and to correlate the improvement of spatial attention to motor control progress after visual spatial training in subjects with unilateral spatial neglect (USN). 9 cases with USN after right cerebral stroke were randomly divided into Conventional treatment group + visual spatial attention and Conventional treatment group. The Conventional treatment group + visual spatial attention received conventional rehabilitation therapy (physical and occupational therapy) and visual spatial attention training (optokinetic stimulation and right half-field eye patching). The Conventional treatment group was only treated with conventional rehabilitation training (physical and occupational therapy). All patients were assessed by behavioral inattention test (BIT), Fugl-Meyer Assessment of motor function (FMA), equilibrium coordination test (ECT) and non-equilibrium coordination test (NCT) before and after 4 weeks treatment. Total scores in both groups (without visual spatial attention/with visual spatial attention) improved significantly (BIT: P=0.021/P=0.000, d=1.667/d=2.116, power=0.69/power=0.98, 95%CI[-0.8839,45.88]/95%CI=[16.96,92.64]; FMA: P=0.002/P=0.000, d=2.521/d=2.700, power=0.93/power=0.98, 95%CI[5.707,30.79]/95%CI=[16.06,53.94]; ECT: P=0.002/ P=0.000, d=2.031/d=1.354, power=0.90/power=0.17, 95%CI[3.380,42.61]/95%CI=[-1.478,39.08]; NCT: P=0.013/P=0.000, d=1.124/d=1.822, power=0.41/power=0.56, 95%CI[-7.980,37.48]/95%CI=[4.798,43.60],) after treatment. Among the 2 groups, the group with visual spatial attention significantly improved in BIT (P=0.003, d=3.103, power=1, 95%CI[15.68,48.92]), FMA of upper extremity (P=0.006, d=2.771, power=1, 95%CI[5.061,20.14]) and NCT (P=0.010, d=2.214, power=0.81-0.90, 95%CI[3.018,15.88]). Correlative analysis shows that the change of BIT scores is positively correlated to the change of FMA total score (r=0.77, P<;0.01), FMA of upper extremity (r=0.81, P<0.01), NCT (r=0.78, P<0.01). Four weeks visual spatial training could improve spatial attention as well as motor control functions in hemineglect patients. The improvement of motor function is positively correlated to the progresses of visual spatial functions after visual spatial attention training.

Dynamic crossmodal links revealed by steady-state responses in auditory-visual divided attention.

PubMed

de Jong, Ritske; Toffanin, Paolo; Harbers, Marten

2010-01-01

Frequency tagging has been often used to study intramodal attention but not intermodal attention. We used EEG and simultaneous frequency tagging of auditory and visual sources to study intermodal focused and divided attention in detection and discrimination performance. Divided-attention costs were smaller, but still significant, in detection than in discrimination. The auditory steady-state response (SSR) showed no effects of attention at frontocentral locations, but did so at occipital locations where it was evident only when attention was divided between audition and vision. Similarly, the visual SSR at occipital locations was substantially enhanced when attention was divided across modalities. Both effects were equally present in detection and discrimination. We suggest that both effects reflect a common cause: An attention-dependent influence of auditory information processing on early cortical stages of visual information processing, mediated by enhanced effective connectivity between the two modalities under conditions of divided attention. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Dividing time: concurrent timing of auditory and visual events by young and elderly adults.

PubMed

McAuley, J Devin; Miller, Jonathan P; Wang, Mo; Pang, Kevin C H

2010-07-01

This article examines age differences in individual's ability to produce the durations of learned auditory and visual target events either in isolation (focused attention) or concurrently (divided attention). Young adults produced learned target durations equally well in focused and divided attention conditions. Older adults, in contrast, showed an age-related increase in timing variability in divided attention conditions that tended to be more pronounced for visual targets than for auditory targets. Age-related impairments were associated with a decrease in working memory span; moreover, the relationship between working memory and timing performance was largest for visual targets in divided attention conditions.

An Issue of Learning: The Effect of Visual Split Attention in Classes for Deaf and Hard of Hearing Students

ERIC Educational Resources Information Center

Mather, Susan M.; Clark, M. Diane

2012-01-01

One of the ongoing challenges teachers of students who are deaf or hard of hearing face is managing the visual split attention implicit in multimedia learning. When a teacher presents various types of visual information at the same time, visual learners have no choice but to divide their attention among those materials and the teacher and…

Evidence for an attentional component of inhibition of return in visual search.

PubMed

Pierce, Allison M; Crouse, Monique D; Green, Jessica J

2017-11-01

Inhibition of return (IOR) is typically described as an inhibitory bias against returning attention to a recently attended location as a means of promoting efficient visual search. Most studies examining IOR, however, either do not use visual search paradigms or do not effectively isolate attentional processes, making it difficult to conclusively link IOR to a bias in attention. Here, we recorded ERPs during a simple visual search task designed to isolate the attentional component of IOR to examine whether an inhibitory bias of attention is observed and, if so, how it influences visual search behavior. Across successive visual search displays, we found evidence of both a broad, hemisphere-wide inhibitory bias of attention along with a focal, target location-specific facilitation. When the target appeared in the same visual hemifield in successive searches, responses were slower and the N2pc component was reduced, reflecting a bias of attention away from the previously attended side of space. When the target occurred at the same location in successive searches, responses were facilitated and the P1 component was enhanced, likely reflecting spatial priming of the target. These two effects are combined in the response times, leading to a reduction in the IOR effect for repeated target locations. Using ERPs, however, these two opposing effects can be isolated in time, demonstrating that the inhibitory biasing of attention still occurs even when response-time slowing is ameliorated by spatial priming. © 2017 Society for Psychophysiological Research.

Top-down alpha oscillatory network interactions during visuospatial attention orienting.

PubMed

Doesburg, Sam M; Bedo, Nicolas; Ward, Lawrence M

2016-05-15

Neuroimaging and lesion studies indicate that visual attention is controlled by a distributed network of brain areas. The covert control of visuospatial attention has also been associated with retinotopic modulation of alpha-band oscillations within early visual cortex, which are thought to underlie inhibition of ignored areas of visual space. The relation between distributed networks mediating attention control and more focal oscillatory mechanisms, however, remains unclear. The present study evaluated the hypothesis that alpha-band, directed, network interactions within the attention control network are systematically modulated by the locus of visuospatial attention. We localized brain areas involved in visuospatial attention orienting using magnetoencephalographic (MEG) imaging and investigated alpha-band Granger-causal interactions among activated regions using narrow-band transfer entropy. The deployment of attention to one side of visual space was indexed by lateralization of alpha power changes between about 400ms and 700ms post-cue onset. The changes in alpha power were associated, in the same time period, with lateralization of anterior-to-posterior information flow in the alpha-band from various brain areas involved in attention control, including the anterior cingulate cortex, left middle and inferior frontal gyri, left superior temporal gyrus, and right insula, and inferior parietal lobule, to early visual areas. We interpreted these results to indicate that distributed network interactions mediated by alpha oscillations exert top-down influences on early visual cortex to modulate inhibition of processing for ignored areas of visual space. Copyright © 2016. Published by Elsevier Inc.

Selective maintenance in visual working memory does not require sustained visual attention.

PubMed

Hollingworth, Andrew; Maxcey-Richard, Ashleigh M

2013-08-01

In four experiments, we tested whether sustained visual attention is required for the selective maintenance of objects in visual working memory (VWM). Participants performed a color change-detection task. During the retention interval, a valid cue indicated the item that would be tested. Change-detection performance was higher in the valid-cue condition than in a neutral-cue control condition. To probe the role of visual attention in the cuing effect, on half of the trials, a difficult search task was inserted after the cue, precluding sustained attention on the cued item. The addition of the search task produced no observable decrement in the magnitude of the cuing effect. In a complementary test, search efficiency was not impaired by simultaneously prioritizing an object for retention in VWM. The results demonstrate that selective maintenance in VWM can be dissociated from the locus of visual attention. 2013 APA, all rights reserved

Effect of oculomotor vision rehabilitation on the visual-evoked potential and visual attention in mild traumatic brain injury.

PubMed

Yadav, Naveen K; Thiagarajan, Preethi; Ciuffreda, Kenneth J

2014-01-01

The purpose of the experiment was to investigate the effect of oculomotor vision rehabilitation (OVR) on the visual-evoked potential (VEP) and visual attention in the mTBI population. Subjects (n = 7) were adults with a history of mild traumatic brain injury (mTBI). Each received 9 hours of OVR over a 6-week period. The effects of OVR on VEP amplitude and latency, the attention-related alpha band (8-13 Hz) power (µV(2)) and the clinical Visual Search and Attention Test (VSAT) were assessed before and after the OVR. After the OVR, the VEP amplitude increased and its variability decreased. There was no change in VEP latency, which was normal. Alpha band power increased, as did the VSAT score, following the OVR. The significant changes in most test parameters suggest that OVR affects the visual system at early visuo-cortical levels, as well as other pathways which are involved in visual attention.

Visual spatial attention enhances the amplitude of positive and negative fMRI responses to visual stimulation in an eccentricity-dependent manner

PubMed Central

Bressler, David W.; Fortenbaugh, Francesca C.; Robertson, Lynn C.; Silver, Michael A.

2013-01-01

Endogenous visual spatial attention improves perception and enhances neural responses to visual stimuli at attended locations. Although many aspects of visual processing differ significantly between central and peripheral vision, little is known regarding the neural substrates of the eccentricity dependence of spatial attention effects. We measured amplitudes of positive and negative fMRI responses to visual stimuli as a function of eccentricity in a large number of topographically-organized cortical areas. Responses to each stimulus were obtained when the stimulus was attended and when spatial attention was directed to a stimulus in the opposite visual hemifield. Attending to the stimulus increased both positive and negative response amplitudes in all cortical areas we studied: V1, V2, V3, hV4, VO1, LO1, LO2, V3A/B, IPS0, TO1, and TO2. However, the eccentricity dependence of these effects differed considerably across cortical areas. In early visual, ventral, and lateral occipital cortex, attentional enhancement of positive responses was greater for central compared to peripheral eccentricities. The opposite pattern was observed in dorsal stream areas IPS0 and putative MT homolog TO1, where attentional enhancement of positive responses was greater in the periphery. Both the magnitude and the eccentricity dependence of attentional modulation of negative fMRI responses closely mirrored that of positive responses across cortical areas. PMID:23562388

Perisaccadic Updating of Visual Representations and Attentional States: Linking Behavior and Neurophysiology

PubMed Central

Marino, Alexandria C.; Mazer, James A.

2016-01-01

During natural vision, saccadic eye movements lead to frequent retinal image changes that result in different neuronal subpopulations representing the same visual feature across fixations. Despite these potentially disruptive changes to the neural representation, our visual percept is remarkably stable. Visual receptive field remapping, characterized as an anticipatory shift in the position of a neuron’s spatial receptive field immediately before saccades, has been proposed as one possible neural substrate for visual stability. Many of the specific properties of remapping, e.g., the exact direction of remapping relative to the saccade vector and the precise mechanisms by which remapping could instantiate stability, remain a matter of debate. Recent studies have also shown that visual attention, like perception itself, can be sustained across saccades, suggesting that the attentional control system can also compensate for eye movements. Classical remapping could have an attentional component, or there could be a distinct attentional analog of visual remapping. At this time we do not yet fully understand how the stability of attentional representations relates to perisaccadic receptive field shifts. In this review, we develop a vocabulary for discussing perisaccadic shifts in receptive field location and perisaccadic shifts of attentional focus, review and synthesize behavioral and neurophysiological studies of perisaccadic perception and perisaccadic attention, and identify open questions that remain to be experimentally addressed. PMID:26903820

Coupling between Theta Oscillations and Cognitive Control Network during Cross-Modal Visual and Auditory Attention: Supramodal vs Modality-Specific Mechanisms.

PubMed

Wang, Wuyi; Viswanathan, Shivakumar; Lee, Taraz; Grafton, Scott T

2016-01-01

Cortical theta band oscillations (4-8 Hz) in EEG signals have been shown to be important for a variety of different cognitive control operations in visual attention paradigms. However the synchronization source of these signals as defined by fMRI BOLD activity and the extent to which theta oscillations play a role in multimodal attention remains unknown. Here we investigated the extent to which cross-modal visual and auditory attention impacts theta oscillations. Using a simultaneous EEG-fMRI paradigm, healthy human participants performed an attentional vigilance task with six cross-modal conditions using naturalistic stimuli. To assess supramodal mechanisms, modulation of theta oscillation amplitude for attention to either visual or auditory stimuli was correlated with BOLD activity by conjunction analysis. Negative correlation was localized to cortical regions associated with the default mode network and positively with ventral premotor areas. Modality-associated attention to visual stimuli was marked by a positive correlation of theta and BOLD activity in fronto-parietal area that was not observed in the auditory condition. A positive correlation of theta and BOLD activity was observed in auditory cortex, while a negative correlation of theta and BOLD activity was observed in visual cortex during auditory attention. The data support a supramodal interaction of theta activity with of DMN function, and modality-associated processes within fronto-parietal networks related to top-down theta related cognitive control in cross-modal visual attention. On the other hand, in sensory cortices there are opposing effects of theta activity during cross-modal auditory attention.

Clinical spectrum of lamellar macular defects including pseudoholes and pseudocysts defined by optical coherence tomography

PubMed Central

Chen, J C; Lee, L R

2008-01-01

Objective: To present the clinical spectrum of lamellar macular defects and describe the different subtypes based on their optical coherence tomography (OCT) configuration and visual prognosis. Methods: The retrospective observational case series reviewed OCT scans of 92 eyes with lamellar macular defects. Lamellar macular defects were categorised into subtypes of macular pseudohole (MPH), lamellar macular hole (LMH) and foveal pseudocyst (FP) according to their OCT morphology. The defects were quantitatively characterised in terms of base diameter, depth and central foveal thickness, and examined for the presence of associated epiretinal membranes (ERM). Results: Visual acuity (VA) was significantly correlated with the central foveal thickness and depth of the lamellar defect. MPH was associated with better VA compared with LMH and FP. MPH was of a smaller base diameter and had a greater central foveal thickness than that of LMH and FP. Fifty-per cent of all lamellar defects had an associated ERM. Conclusions: Different profiles of lamellar macular defects were characterised and quantified by OCT. Deeper and wider lamellar defects were associated with poorer visual outcome. Such objective parameters lamellar macular defects are of value when explaining to patients regarding their decreased acuity. Future prospective investigations are required to study the natural history of lamellar defects of different aetiology and surgical indications. PMID:18684752

Visual attention spreads broadly but selects information locally.

PubMed

Shioiri, Satoshi; Honjyo, Hajime; Kashiwase, Yoshiyuki; Matsumiya, Kazumichi; Kuriki, Ichiro

2016-10-19

Visual attention spreads over a range around the focus as the spotlight metaphor describes. Spatial spread of attentional enhancement and local selection/inhibition are crucial factors determining the profile of the spatial attention. Enhancement and ignorance/suppression are opposite effects of attention, and appeared to be mutually exclusive. Yet, no unified view of the factors has been provided despite their necessity for understanding the functions of spatial attention. This report provides electroencephalographic and behavioral evidence for the attentional spread at an early stage and selection/inhibition at a later stage of visual processing. Steady state visual evoked potential showed broad spatial tuning whereas the P3 component of the event related potential showed local selection or inhibition of the adjacent areas. Based on these results, we propose a two-stage model of spatial attention with broad spread at an early stage and local selection at a later stage.

Saccade frequency response to visual cues during gait in Parkinson's disease: the selective role of attention.

PubMed

Stuart, Samuel; Lord, Sue; Galna, Brook; Rochester, Lynn

2018-04-01

Gait impairment is a core feature of Parkinson's disease (PD) with implications for falls risk. Visual cues improve gait in PD, but the underlying mechanisms are unclear. Evidence suggests that attention and vision play an important role; however, the relative contribution from each is unclear. Measurement of visual exploration (specifically saccade frequency) during gait allows for real-time measurement of attention and vision. Understanding how visual cues influence visual exploration may allow inferences of the underlying mechanisms to response which could help to develop effective therapeutics. This study aimed to examine saccade frequency during gait in response to a visual cue in PD and older adults and investigate the roles of attention and vision in visual cue response in PD. A mobile eye-tracker measured saccade frequency during gait in 55 people with PD and 32 age-matched controls. Participants walked in a straight line with and without a visual cue (50 cm transverse lines) presented under single task and dual-task (concurrent digit span recall). Saccade frequency was reduced when walking in PD compared to controls; however, visual cues ameliorated saccadic deficit. Visual cues significantly increased saccade frequency in both PD and controls under both single task and dual-task. Attention rather than visual function was central to saccade frequency and gait response to visual cues in PD. In conclusion, this study highlights the impact of visual cues on visual exploration when walking and the important role of attention in PD. Understanding these complex features will help inform intervention development. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Resource-sharing between internal maintenance and external selection modulates attentional capture by working memory content.

PubMed

Kiyonaga, Anastasia; Egner, Tobias

2014-01-01

It is unclear why and under what circumstances working memory (WM) and attention interact. Here, we apply the logic of the time-based resource-sharing (TBRS) model of WM (e.g., Barrouillet et al., 2004) to explore the mixed findings of a separate, but related, literature that studies the guidance of visual attention by WM contents. Specifically, we hypothesize that the linkage between WM representations and visual attention is governed by a time-shared cognitive resource that alternately refreshes internal (WM) and selects external (visual attention) information. If this were the case, WM content should guide visual attention (involuntarily), but only when there is time for it to be refreshed in an internal focus of attention. To provide an initial test for this hypothesis, we examined whether the amount of unoccupied time during a WM delay could impact the magnitude of attentional capture by WM contents. Participants were presented with a series of visual search trials while they maintained a WM cue for a delayed-recognition test. WM cues could coincide with the search target, a distracter, or neither. We varied both the number of searches to be performed, and the amount of available time to perform them. Slowing of visual search by a WM matching distracter-and facilitation by a matching target-were curtailed when the delay was filled with fast-paced (refreshing-preventing) search trials, as was subsequent memory probe accuracy. WM content may, therefore, only capture visual attention when it can be refreshed, suggesting that internal (WM) and external attention demands reciprocally impact one another because they share a limited resource. The TBRS rationale can thus be applied in a novel context to explain why WM contents capture attention, and under what conditions that effect should be observed.

Resource-sharing between internal maintenance and external selection modulates attentional capture by working memory content

PubMed Central

Kiyonaga, Anastasia; Egner, Tobias

2014-01-01

It is unclear why and under what circumstances working memory (WM) and attention interact. Here, we apply the logic of the time-based resource-sharing (TBRS) model of WM (e.g., Barrouillet et al., 2004) to explore the mixed findings of a separate, but related, literature that studies the guidance of visual attention by WM contents. Specifically, we hypothesize that the linkage between WM representations and visual attention is governed by a time-shared cognitive resource that alternately refreshes internal (WM) and selects external (visual attention) information. If this were the case, WM content should guide visual attention (involuntarily), but only when there is time for it to be refreshed in an internal focus of attention. To provide an initial test for this hypothesis, we examined whether the amount of unoccupied time during a WM delay could impact the magnitude of attentional capture by WM contents. Participants were presented with a series of visual search trials while they maintained a WM cue for a delayed-recognition test. WM cues could coincide with the search target, a distracter, or neither. We varied both the number of searches to be performed, and the amount of available time to perform them. Slowing of visual search by a WM matching distracter—and facilitation by a matching target—were curtailed when the delay was filled with fast-paced (refreshing-preventing) search trials, as was subsequent memory probe accuracy. WM content may, therefore, only capture visual attention when it can be refreshed, suggesting that internal (WM) and external attention demands reciprocally impact one another because they share a limited resource. The TBRS rationale can thus be applied in a novel context to explain why WM contents capture attention, and under what conditions that effect should be observed. PMID:25221499

Haptic guidance of overt visual attention.

PubMed

List, Alexandra; Iordanescu, Lucica; Grabowecky, Marcia; Suzuki, Satoru

2014-11-01

Research has shown that information accessed from one sensory modality can influence perceptual and attentional processes in another modality. Here, we demonstrated a novel crossmodal influence of haptic-shape information on visual attention. Participants visually searched for a target object (e.g., an orange) presented among distractor objects, fixating the target as quickly as possible. While searching for the target, participants held (never viewed and out of sight) an item of a specific shape in their hands. In two experiments, we demonstrated that the time for the eyes to reach a target-a measure of overt visual attention-was reduced when the shape of the held item (e.g., a sphere) was consistent with the shape of the visual target (e.g., an orange), relative to when the held shape was unrelated to the target (e.g., a hockey puck) or when no shape was held. This haptic-to-visual facilitation occurred despite the fact that the held shapes were not predictive of the visual targets' shapes, suggesting that the crossmodal influence occurred automatically, reflecting shape-specific haptic guidance of overt visual attention.

Spatial working memory interferes with explicit, but not probabilistic cuing of spatial attention.

PubMed

Won, Bo-Yeong; Jiang, Yuhong V

2015-05-01

Recent empirical and theoretical work has depicted a close relationship between visual attention and visual working memory. For example, rehearsal in spatial working memory depends on spatial attention, whereas adding a secondary spatial working memory task impairs attentional deployment in visual search. These findings have led to the proposal that working memory is attention directed toward internal representations. Here, we show that the close relationship between these 2 constructs is limited to some but not all forms of spatial attention. In 5 experiments, participants held color arrays, dot locations, or a sequence of dots in working memory. During the memory retention interval, they performed a T-among-L visual search task. Crucially, the probable target location was cued either implicitly through location probability learning or explicitly with a central arrow or verbal instruction. Our results showed that whereas imposing a visual working memory load diminished the effectiveness of explicit cuing, it did not interfere with probability cuing. We conclude that spatial working memory shares similar mechanisms with explicit, goal-driven attention but is dissociated from implicitly learned attention. (c) 2015 APA, all rights reserved).

Spatial working memory interferes with explicit, but not probabilistic cuing of spatial attention

PubMed Central

Won, Bo-Yeong; Jiang, Yuhong V.

2014-01-01

Recent empirical and theoretical work has depicted a close relationship between visual attention and visual working memory. For example, rehearsal in spatial working memory depends on spatial attention, whereas adding a secondary spatial working memory task impairs attentional deployment in visual search. These findings have led to the proposal that working memory is attention directed toward internal representations. Here we show that the close relationship between these two constructs is limited to some but not all forms of spatial attention. In five experiments, participants held color arrays, dot locations, or a sequence of dots in working memory. During the memory retention interval they performed a T-among-L visual search task. Crucially, the probable target location was cued either implicitly through location probability learning, or explicitly with a central arrow or verbal instruction. Our results showed that whereas imposing a visual working memory load diminished the effectiveness of explicit cuing, it did not interfere with probability cuing. We conclude that spatial working memory shares similar mechanisms with explicit, goal-driven attention but is dissociated from implicitly learned attention. PMID:25401460

Collinearity Impairs Local Element Visual Search

ERIC Educational Resources Information Center

Jingling, Li; Tseng, Chia-Huei

2013-01-01

In visual searches, stimuli following the law of good continuity attract attention to the global structure and receive attentional priority. Also, targets that have unique features are of high feature contrast and capture attention in visual search. We report on a salient global structure combined with a high orientation contrast to the…

Contextual Cueing: Implicit Learning and Memory of Visual Context Guides Spatial Attention.

ERIC Educational Resources Information Center

Chun, Marvin M.; Jiang, Yuhong

1998-01-01

Six experiments involving a total of 112 college students demonstrate that a robust memory for visual context exists to guide spatial attention. Results show how implicit learning and memory of visual context can guide spatial attention toward task-relevant aspects of a scene. (SLD)

Visual Memory for Objects Following Foveal Vision Loss

ERIC Educational Resources Information Center

Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B.; Pollmann, Stefan

2015-01-01

Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual…

Modality-specificity of Selective Attention Networks.

PubMed

Stewart, Hannah J; Amitay, Sygal

2015-01-01

To establish the modality specificity and generality of selective attention networks. Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT), the Test of Everyday Attention (TEA), and the Test of Attention in Listening (TAiL). These provided independent measures for auditory and visual alerting, orienting, and conflict resolution networks. The measures were subjected to an exploratory factor analysis to assess underlying attention constructs. The analysis yielded a four-component solution. The first component comprised of a range of measures from the TEA and was labeled "general attention." The third component was labeled "auditory attention," as it only contained measures from the TAiL using pitch as the attended stimulus feature. The second and fourth components were labeled as "spatial orienting" and "spatial conflict," respectively-they were comprised of orienting and conflict resolution measures from the vANT, aANT, and TAiL attend-location task-all tasks based upon spatial judgments (e.g., the direction of a target arrow or sound location). These results do not support our a-priori hypothesis that attention networks are either modality specific or supramodal. Auditory attention separated into selectively attending to spatial and non-spatial features, with the auditory spatial attention loading onto the same factor as visual spatial attention, suggesting spatial attention is supramodal. However, since our study did not include a non-spatial measure of visual attention, further research will be required to ascertain whether non-spatial attention is modality-specific.

Early auditory evoked potential is modulated by selective attention and related to individual differences in visual working memory capacity.

PubMed

Giuliano, Ryan J; Karns, Christina M; Neville, Helen J; Hillyard, Steven A

2014-12-01

A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual's capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70-90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals.

Retinotopic patterns of background connectivity between V1 and fronto-parietal cortex are modulated by task demands

PubMed Central

Griffis, Joseph C.; Elkhetali, Abdurahman S.; Burge, Wesley K.; Chen, Richard H.; Visscher, Kristina M.

2015-01-01

Attention facilitates the processing of task-relevant visual information and suppresses interference from task-irrelevant information. Modulations of neural activity in visual cortex depend on attention, and likely result from signals originating in fronto-parietal and cingulo-opercular regions of cortex. Here, we tested the hypothesis that attentional facilitation of visual processing is accomplished in part by changes in how brain networks involved in attentional control interact with sectors of V1 that represent different retinal eccentricities. We measured the strength of background connectivity between fronto-parietal and cingulo-opercular regions with different eccentricity sectors in V1 using functional MRI data that were collected while participants performed tasks involving attention to either a centrally presented visual stimulus or a simultaneously presented auditory stimulus. We found that when the visual stimulus was attended, background connectivity between V1 and the left frontal eye fields (FEF), left intraparietal sulcus (IPS), and right IPS varied strongly across different eccentricity sectors in V1 so that foveal sectors were more strongly connected than peripheral sectors. This retinotopic gradient was weaker when the visual stimulus was ignored, indicating that it was driven by attentional effects. Greater task-driven differences between foveal and peripheral sectors in background connectivity to these regions were associated with better performance on the visual task and faster response times on correct trials. These findings are consistent with the notion that attention drives the configuration of task-specific functional pathways that enable the prioritized processing of task-relevant visual information, and show that the prioritization of visual information by attentional processes may be encoded in the retinotopic gradient of connectivty between V1 and fronto-parietal regions. PMID:26106320

Updated cannulation technique for tissue plasminogen activator injection into peripapillary retinal vein for central retinal vein occlusion.

PubMed

van Overdam, Koen A; Missotten, Tom; Spielberg, Leigh H

2015-12-01

To update the surgical technique in which a vitrectomy is performed and a retinal branch vein is cannulated and infused with recombinant tissue plasminogen activator (RTPA) to treat central retinal vein occlusion (CRVO) in patients who present with very low visual acuity (VA). Twelve consecutive patients (12 eyes) with CRVO and low VA (logMAR >1.00) at presentation were treated using this method. Cannulation of a peripapillary retinal vein and stable injection of RTPA was successfully performed without surgery-related complications in all 12 eyes. At 12 months after surgery, 8 of the 12 patients (67%) experienced at least one line of improvement in best corrected visual acuity; 6 of the 12 (50%) improved ≥5 lines and 2 (17%) improved ≥8 lines. After additional grid laser and/or subconjunctival or intravitreal corticosteroids, the mean decrease in central foveal thickness was 260 μm, and the mean total macular volume decreased from 12.10 mm(3) to 9.24 mm(3) . Four patients received panretinal photocoagulation to treat either iris neovascularization (n = 2) or neovascularization of the retina and/or disc (n = 2). Administration of RTPA via a peripapillary vein using this updated technique provides an alternative or additional treatment option for patients with very low VA after CRVO. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Outcomes of 3 hours part-time occlusion treatment combined with near activities among children with unilateral amblyopia.

PubMed

Alotaibi, Abdullah G; Fawazi, Samah M; Alenazy, Badriah R; Abu-Amero, Khaled K

2012-04-01

To evaluate the outcome of part-time occlusion therapy with or without near activities in monocular amblyopic patients. One hundred and thirty patients who prescribed daily occlusion therapy (part-time occlusion) were followed-up for a 12-week period. The study was carried out in the Pediatric Ophthalmology and Orthoptics Clinics of King Abdul-Aziz University Hospital, Riyadh, Saudi Arabia for the period from January to November 2010. Sixty-five patients were recommended to undertake the 3 hours of near visual activities (such as reading a book during patching) while the other 65 patients were not advised to do any near activity. Main outcome measures were best corrected visual acuity (VA) for both groups and line improvement. The total line of VA improved from baseline by an average of 6.7+/-2.37 line log MAR (logarithm of the minimum angle of resolution) units in the group of patching with near activities and by an average of 5.3+/- 2.04 line log MAR units in the group of patching without near activities. All type of amblyopia (strabismic, anisometropic, and mixed types of amblyopia) improved significantly after patching with near activities. Both moderate and severe amblyopia improved significantly in the group of near activities compared with the group without near activities. Performing near activities while patching in the treatment of anisometropic, stabismic, or combined amblyopia improves the VA outcome more than patching alone.

Pacing Visual Attention: Temporal Structure Effects

DTIC Science & Technology

1993-06-01

of perception and motor action: Ideomotor compatibility and interference in divided attention . Journal of Motor Behavior, 2, (3), 155-162. Kwak, H...1993 Dissertation, Jun 89 - Jun 93 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Pacing Visual Attention : Temporal Structure Effects PE - 62202F 6. AUTHOR(S...that persisting temporal relationships may be an important factor in the external (exogenous) control of visual attention , at least to some extent, was

Perception and Attention for Visualization

ERIC Educational Resources Information Center

Haroz, Steve

2013-01-01

This work examines how a better understanding of visual perception and attention can impact visualization design. In a collection of studies, I explore how different levels of the visual system can measurably affect a variety of visualization metrics. The results show that expert preference, user performance, and even computational performance are…

Not All Attention Orienting is Created Equal: Recognition Memory is Enhanced When Attention Orienting Involves Distractor Suppression

PubMed Central

Markant, Julie; Worden, Michael S.; Amso, Dima

2015-01-01

Learning through visual exploration often requires orienting of attention to meaningful information in a cluttered world. Previous work has shown that attention modulates visual cortex activity, with enhanced activity for attended targets and suppressed activity for competing inputs, thus enhancing the visual experience. Here we examined the idea that learning may be engaged differentially with variations in attention orienting mechanisms that drive driving eye movements during visual search and exploration. We hypothesized that attention orienting mechanisms that engaged suppression of a previously attended location will boost memory encoding of the currently attended target objects to a greater extent than those that involve target enhancement alone To test this hypothesis we capitalized on the classic spatial cueing task and the inhibition of return (IOR) mechanism (Posner, Rafal, & Choate, 1985; Posner, 1980) to demonstrate that object images encoded in the context of concurrent suppression at a previously attended location were encoded more effectively and remembered better than those encoded without concurrent suppression. Furthermore, fMRI analyses revealed that this memory benefit was driven by attention modulation of visual cortex activity, as increased suppression of the previously attended location in visual cortex during target object encoding predicted better subsequent recognition memory performance. These results suggest that not all attention orienting impacts learning and memory equally. PMID:25701278

Impaired visual search in rats reveals cholinergic contributions to feature binding in visuospatial attention.

PubMed

Botly, Leigh C P; De Rosa, Eve

2012-10-01

The visual search task established the feature integration theory of attention in humans and measures visuospatial attentional contributions to feature binding. We recently demonstrated that the neuromodulator acetylcholine (ACh), from the nucleus basalis magnocellularis (NBM), supports the attentional processes required for feature binding using a rat digging-based task. Additional research has demonstrated cholinergic contributions from the NBM to visuospatial attention in rats. Here, we combined these lines of evidence and employed visual search in rats to examine whether cortical cholinergic input supports visuospatial attention specifically for feature binding. We trained 18 male Long-Evans rats to perform visual search using touch screen-equipped operant chambers. Sessions comprised Feature Search (no feature binding required) and Conjunctive Search (feature binding required) trials using multiple stimulus set sizes. Following acquisition of visual search, 8 rats received bilateral NBM lesions using 192 IgG-saporin to selectively reduce cholinergic afferentation of the neocortex, which we hypothesized would selectively disrupt the visuospatial attentional processes needed for efficient conjunctive visual search. As expected, relative to sham-lesioned rats, ACh-NBM-lesioned rats took significantly longer to locate the target stimulus on Conjunctive Search, but not Feature Search trials, thus demonstrating that cholinergic contributions to visuospatial attention are important for feature binding in rats.

A results-based process for evaluation of diverse visual analytics tools

NASA Astrophysics Data System (ADS)

Rubin, Gary; Berger, David H.

2013-05-01

With the pervasiveness of still and full-motion imagery in commercial and military applications, the need to ingest and analyze these media has grown rapidly in recent years. Additionally, video hosting and live camera websites provide a near real-time view of our changing world with unprecedented spatial coverage. To take advantage of these controlled and crowd-sourced opportunities, sophisticated visual analytics (VA) tools are required to accurately and efficiently convert raw imagery into usable information. Whether investing in VA products or evaluating algorithms for potential development, it is important for stakeholders to understand the capabilities and limitations of visual analytics tools. Visual analytics algorithms are being applied to problems related to Intelligence, Surveillance, and Reconnaissance (ISR), facility security, and public safety monitoring, to name a few. The diversity of requirements means that a onesize- fits-all approach to performance assessment will not work. We present a process for evaluating the efficacy of algorithms in real-world conditions, thereby allowing users and developers of video analytics software to understand software capabilities and identify potential shortcomings. The results-based approach described in this paper uses an analysis of end-user requirements and Concept of Operations (CONOPS) to define Measures of Effectiveness (MOEs), test data requirements, and evaluation strategies. We define metrics that individually do not fully characterize a system, but when used together, are a powerful way to reveal both strengths and weaknesses. We provide examples of data products, such as heatmaps, performance maps, detection timelines, and rank-based probability-of-detection curves.

Typical visual search performance and atypical gaze behaviors in response to faces in Williams syndrome.

PubMed

Hirai, Masahiro; Muramatsu, Yukako; Mizuno, Seiji; Kurahashi, Naoko; Kurahashi, Hirokazu; Nakamura, Miho

2016-01-01

Evidence indicates that individuals with Williams syndrome (WS) exhibit atypical attentional characteristics when viewing faces. However, the dynamics of visual attention captured by faces remain unclear, especially when explicit attentional forces are present. To clarify this, we introduced a visual search paradigm and assessed how the relative strength of visual attention captured by a face and explicit attentional control changes as search progresses. Participants (WS and controls) searched for a target (butterfly) within an array of distractors, which sometimes contained an upright face. We analyzed reaction time and location of the first fixation-which reflect the attentional profile at the initial stage-and fixation durations. These features represent aspects of attention at later stages of visual search. The strength of visual attention captured by faces and explicit attentional control (toward the butterfly) was characterized by the frequency of first fixations on a face or butterfly and on the duration of face or butterfly fixations. Although reaction time was longer in all groups when faces were present, and visual attention was not dominated by faces in any group during the initial stages of the search, when faces were present, attention to faces dominated in the WS group during the later search stages. Furthermore, for the WS group, reaction time correlated with eye-movement measures at different stages of searching such that longer reaction times were associated with longer face-fixations, specifically at the initial stage of searching. Moreover, longer reaction times were associated with longer face-fixations at the later stages of searching, while shorter reaction times were associated with longer butterfly fixations. The relative strength of attention captured by faces in people with WS is not observed at the initial stage of searching but becomes dominant as the search progresses. Furthermore, although behavioral responses are associated with some aspects of eye movements, they are not as sensitive as eye-movement measurements themselves at detecting atypical attentional characteristics in people with WS.

The Attentional Drift Diffusion Model of Simple Perceptual Decision-Making.

PubMed

Tavares, Gabriela; Perona, Pietro; Rangel, Antonio

2017-01-01

Perceptual decisions requiring the comparison of spatially distributed stimuli that are fixated sequentially might be influenced by fluctuations in visual attention. We used two psychophysical tasks with human subjects to investigate the extent to which visual attention influences simple perceptual choices, and to test the extent to which the attentional Drift Diffusion Model (aDDM) provides a good computational description of how attention affects the underlying decision processes. We find evidence for sizable attentional choice biases and that the aDDM provides a reasonable quantitative description of the relationship between fluctuations in visual attention, choices and reaction times. We also find that exogenous manipulations of attention induce choice biases consistent with the predictions of the model.

Cognitive Control Network Contributions to Memory-Guided Visual Attention.

PubMed

Rosen, Maya L; Stern, Chantal E; Michalka, Samantha W; Devaney, Kathryn J; Somers, David C

2016-05-01

Visual attentional capacity is severely limited, but humans excel in familiar visual contexts, in part because long-term memories guide efficient deployment of attention. To investigate the neural substrates that support memory-guided visual attention, we performed a set of functional MRI experiments that contrast long-term, memory-guided visuospatial attention with stimulus-guided visuospatial attention in a change detection task. Whereas the dorsal attention network was activated for both forms of attention, the cognitive control network(CCN) was preferentially activated during memory-guided attention. Three posterior nodes in the CCN, posterior precuneus, posterior callosal sulcus/mid-cingulate, and lateral intraparietal sulcus exhibited the greatest specificity for memory-guided attention. These 3 regions exhibit functional connectivity at rest, and we propose that they form a subnetwork within the broader CCN. Based on the task activation patterns, we conclude that the nodes of this subnetwork are preferentially recruited for long-term memory guidance of visuospatial attention. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Top-Down Control of Visual Attention by the Prefrontal Cortex. Functional Specialization and Long-Range Interactions

PubMed Central

Paneri, Sofia; Gregoriou, Georgia G.

2017-01-01

The ability to select information that is relevant to current behavioral goals is the hallmark of voluntary attention and an essential part of our cognition. Attention tasks are a prime example to study at the neuronal level, how task related information can be selectively processed in the brain while irrelevant information is filtered out. Whereas, numerous studies have focused on elucidating the mechanisms of visual attention at the single neuron and population level in the visual cortices, considerably less work has been devoted to deciphering the distinct contribution of higher-order brain areas, which are known to be critical for the employment of attention. Among these areas, the prefrontal cortex (PFC) has long been considered a source of top-down signals that bias selection in early visual areas in favor of the attended features. Here, we review recent experimental data that support the role of PFC in attention. We examine the existing evidence for functional specialization within PFC and we discuss how long-range interactions between PFC subregions and posterior visual areas may be implemented in the brain and contribute to the attentional modulation of different measures of neural activity in visual cortices. PMID:29033784

Top-Down Control of Visual Attention by the Prefrontal Cortex. Functional Specialization and Long-Range Interactions.

PubMed

Paneri, Sofia; Gregoriou, Georgia G

2017-01-01

The ability to select information that is relevant to current behavioral goals is the hallmark of voluntary attention and an essential part of our cognition. Attention tasks are a prime example to study at the neuronal level, how task related information can be selectively processed in the brain while irrelevant information is filtered out. Whereas, numerous studies have focused on elucidating the mechanisms of visual attention at the single neuron and population level in the visual cortices, considerably less work has been devoted to deciphering the distinct contribution of higher-order brain areas, which are known to be critical for the employment of attention. Among these areas, the prefrontal cortex (PFC) has long been considered a source of top-down signals that bias selection in early visual areas in favor of the attended features. Here, we review recent experimental data that support the role of PFC in attention. We examine the existing evidence for functional specialization within PFC and we discuss how long-range interactions between PFC subregions and posterior visual areas may be implemented in the brain and contribute to the attentional modulation of different measures of neural activity in visual cortices.

Changes in search rate but not in the dynamics of exogenous attention in action videogame players.

PubMed

Hubert-Wallander, Bjorn; Green, C Shawn; Sugarman, Michael; Bavelier, Daphne

2011-11-01

Many previous studies have shown that the speed of processing in attentionally demanding tasks seems enhanced following habitual action videogame play. However, using one of the diagnostic tasks for efficiency of attentional processing, a visual search task, Castel and collaborators (Castel, Pratt, & Drummond, Acta Psychologica 119:217-230, 2005) reported no difference in visual search rates, instead proposing that action gaming may change response execution time rather than the efficiency of visual selective attention per se. Here we used two hard visual search tasks, one measuring reaction time and the other accuracy, to test whether visual search rate may be changed by action videogame play. We found greater search rates in the gamer group than in the nongamer controls, consistent with increased efficiency in visual selective attention. We then asked how general the change in attentional throughput noted so far in gamers might be by testing whether exogenous attentional cues would lead to a disproportional enhancement in throughput in gamers as compared to nongamers. Interestingly, exogenous cues were found to enhance throughput equivalently between gamers and nongamers, suggesting that not all mechanisms known to enhance throughput are similarly enhanced in action videogamers.

Visual selective attention and reading efficiency are related in children.

PubMed

Casco, C; Tressoldi, P E; Dellantonio, A

1998-09-01

We investigated the relationship between visual selective attention and linguistic performance. Subjects were classified in four categories according to their accuracy in a letter cancellation task involving selective attention. The task consisted in searching a target letter in a set of background letters and accuracy was measured as a function of set size. We found that children with the lowest performance in the cancellation task present a significantly slower reading rate and a higher number of reading visual errors than children with highest performance. Results also show that these groups of searchers present significant differences in a lexical search task whereas their performance did not differ in lexical decision and syllables control task. The relationship between letter search and reading, as well as the finding that poor readers-searchers perform poorly lexical search tasks also involving selective attention, suggest that the relationship between letter search and reading difficulty may reflect a deficit in a visual selective attention mechanisms which is involved in all these tasks. A deficit in visual attention can be linked to the problems that disabled readers present in the function of magnocellular stream which culminates in posterior parietal cortex, an area which plays an important role in guiding visual attention.

Eccentricity effects in vision and attention.

PubMed

Staugaard, Camilla Funch; Petersen, Anders; Vangkilde, Signe

2016-11-01

Stimulus eccentricity affects visual processing in multiple ways. Performance on a visual task is often better when target stimuli are presented near or at the fovea compared to the retinal periphery. For instance, reaction times and error rates are often reported to increase with increasing eccentricity. Such findings have been interpreted as purely visual, reflecting neurophysiological differences in central and peripheral vision, as well as attentional, reflecting a central bias in the allocation of attentional resources. Other findings indicate that in some cases, information from the periphery is preferentially processed. Specifically, it has been suggested that visual processing speed increases with increasing stimulus eccentricity, and that this positive correlation is reduced, but not eliminated, when the amount of cortex activated by a stimulus is kept constant by magnifying peripheral stimuli (Carrasco et al., 2003). In this study, we investigated effects of eccentricity on visual attentional capacity with and without magnification, using computational modeling based on Bundesen's (1990) theory of visual attention. Our results suggest a general decrease in attentional capacity with increasing stimulus eccentricity, irrespective of magnification. We discuss these results in relation to the physiology of the visual system, the use of different paradigms for investigating visual perception across the visual field, and the use of different stimulus materials (e.g. Gabor patches vs. letters). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Behavioral and Brain Measures of Phasic Alerting Effects on Visual Attention.

PubMed

Wiegand, Iris; Petersen, Anders; Finke, Kathrin; Bundesen, Claus; Lansner, Jon; Habekost, Thomas

2017-01-01

In the present study, we investigated effects of phasic alerting on visual attention in a partial report task, in which half of the displays were preceded by an auditory warning cue. Based on the computational Theory of Visual Attention (TVA), we estimated parameters of spatial and non-spatial aspects of visual attention and measured event-related lateralizations (ERLs) over visual processing areas. We found that the TVA parameter sensory effectiveness a , which is thought to reflect visual processing capacity, significantly increased with phasic alerting. By contrast, the distribution of visual processing resources according to task relevance and spatial position, as quantified in parameters top-down control α and spatial bias w index , was not modulated by phasic alerting. On the electrophysiological level, the latencies of ERLs in response to the task displays were reduced following the warning cue. These results suggest that phasic alerting facilitates visual processing in a general, unselective manner and that this effect originates in early stages of visual information processing.

Saccade-synchronized rapid attention shifts in macaque visual cortical area MT.

PubMed

Yao, Tao; Treue, Stefan; Krishna, B Suresh

2018-03-06

While making saccadic eye-movements to scan a visual scene, humans and monkeys are able to keep track of relevant visual stimuli by maintaining spatial attention on them. This ability requires a shift of attentional modulation from the neuronal population representing the relevant stimulus pre-saccadically to the one representing it post-saccadically. For optimal performance, this trans-saccadic attention shift should be rapid and saccade-synchronized. Whether this is so is not known. We trained two rhesus monkeys to make saccades while maintaining covert attention at a fixed spatial location. We show that the trans-saccadic attention shift in cortical visual medial temporal (MT) area is well synchronized to saccades. Attentional modulation crosses over from the pre-saccadic to the post-saccadic neuronal representation by about 50 ms after a saccade. Taking response latency into account, the trans-saccadic attention shift is well timed to maintain spatial attention on relevant stimuli, so that they can be optimally tracked and processed across saccades.

Shifting Attention within Memory Representations Involves Early Visual Areas

PubMed Central

Munneke, Jaap; Belopolsky, Artem V.; Theeuwes, Jan

2012-01-01

Prior studies have shown that spatial attention modulates early visual cortex retinotopically, resulting in enhanced processing of external perceptual representations. However, it is not clear whether the same visual areas are modulated when attention is focused on, and shifted within a working memory representation. In the current fMRI study participants were asked to memorize an array containing four stimuli. After a delay, participants were presented with a verbal cue instructing them to actively maintain the location of one of the stimuli in working memory. Additionally, on a number of trials a second verbal cue instructed participants to switch attention to the location of another stimulus within the memorized representation. Results of the study showed that changes in the BOLD pattern closely followed the locus of attention within the working memory representation. A decrease in BOLD-activity (V1–V3) was observed at ROIs coding a memory location when participants switched away from this location, whereas an increase was observed when participants switched towards this location. Continuous increased activity was obtained at the memorized location when participants did not switch. This study shows that shifting attention within memory representations activates the earliest parts of visual cortex (including V1) in a retinotopic fashion. We conclude that even in the absence of visual stimulation, early visual areas support shifting of attention within memorized representations, similar to when attention is shifted in the outside world. The relationship between visual working memory and visual mental imagery is discussed in light of the current findings. PMID:22558165

Effects of Binaural Sensory Aids on the Development of Visual Perceptual Abilities in Visually Handicapped Infants. Final Report, April 15, 1982-November 15, 1982.

ERIC Educational Resources Information Center

Hart, Verna; Ferrell, Kay

Twenty-four congenitally visually handicapped infants, aged 6-24 months, participated in a study to determine (1) those stimuli best able to elicit visual attention, (2) the stability of visual acuity over time, and (3) the effects of binaural sensory aids on both visual attention and visual acuity. Ss were dichotomized into visually handicapped…