Intraocular pressure and ocular biometric parameters changes in migraine.

PubMed

Koban, Yaran; Ozlece, Hatice Kose; Bilgin, Gorkem; Koc, Mustafa; Cagatay, Halil Huseyin; Durgunlu, Emre I; Burcu, Ayse

2016-05-31

The aim of this study was to assess the intraocular pressure and ocular biometric parameters in migraine patients during acute migraine attacks and compare them with painless period and healthy controls using a new optical biometer AL-Scan. In this prospective, case-control study, the axial length, corneal curvature radius, anterior chamber depth, central corneal thickness, and pupil size of 40 migraine patients during acute migraine attacks and painless period and 40 age- and sex-matched healthy subjects were measured using a AL-Scan optical biometer (Nidek Co., Gamagori, Japan). All patients underwent a complete ophthalmic examination before the measurements. IOP and biometer measurements were taken at the same time of day (10:00-12:00) in order to minimize the effects of diurnal variation. There was not a statistically significant difference in intraocular pressure between the migraine patients during acute migraine attacks (15.07 mmHg), painless period (14.10 mmHg), and the controls (15,73 ± 0,81). Also, the ocular biometric parameters did not significantly vary during the acute migraine attacks. Further studies are needed to evaluate the etiopathologic relationship between intraocular pressure and ocular biometric parameters and acute migraine attack.

Head-down posture in glaucoma suspects induces changes in IOP, systemic pressure and PERG that predict future loss of optic nerve tissue

PubMed Central

Porciatti, Vittorio; Feuer, William J.; Monsalve, Pedro; Triolo, Giacinto; Vazquez, Luis; McSoley, John; Ventura, Lori M.

2017-01-01

Purpose To obtain pilot data on posture-induced changes of IOP, systemic pressure and pattern electroretinogram (PERG) predictive of future optic nerve tissue loss glaucoma suspects (GS). Methods Mean peripapillary retinal fiber layer thickness (RNFLT) was measured with OCT two times/year in 28 GS aged 58 ± 8.9 years over 5.0 ± 0.73 years. All patients had a baseline PERG, IOP and brachial blood pressure measurements in the seated and – 10 degrees head-down-body-tilt position (HDT). Outcome measures were seated/HDT PERG amplitude and phase, IOP, mean arterial blood pressure (MAP), and estimated ocular perfusion pressure (OPP). An additional group of 11 similarly-aged controls (SAC) aged 56.9 ± 13 years was tested for comparison. Results While all GS had initial RNFLT in the normal range, 9/28 of them developed significant (P < 0.05) loss of mean RNFLT (thinners, T) over the follow-up period as opposed to 19/28 who did not (non-thinners, NT). Significant (P<0.05) differences between SAC, NT and T were found in PERG amplitude, PERG phase, MAP, IOP, and OPP. A nominal logistic regression using baseline PERG and hemodynamic variables was able to distinguish T from NT with an AUROC of 0.89 (SE 0.07). Conclusions Baseline PERG, IOP, and systemic blood pressure, together with their changes upon HDT, may have predictive value for future loss of optic nerve tissue in GS. This study supports the rationale for a full-scale clinical trial to identify patients at high-risk of development of glaucoma. PMID:28263259

Ocular perfusion pressure and color Doppler imaging of the external ophthalmic artery of rabbits treated with sildenafil citrate.

PubMed

Costa, Ana Paula Araujo; Lima, Aline Maria Vasconcelos; da Silva, Luiz Henrique; de Oliveira Alves Carvalho, Rosângela; do Amaral, Andréia Vitor Couto; Borges, Naida Cristina

2016-07-22

It has been proposed that sildenafil citrate can increase ocular blood flow, and that this property can be used to treat ocular disorders that involve reflex vasoconstriction. This study therefore proposes to ascertain the vasodilator effect of the drug on retrobulbar circulation in healthy rabbits. For this matter rabbits treated with sildenafil citrate or saline solution had their intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (OPP) and color Doppler imaging of the external ophthalmic artery measured prior to treatment and on days one (moment M1), seven (when M2), fourteen (moment M3), twenty-one (moment M4), and thirty (moment M5) of treatment. The MAP and OPP values of treated group were lower than those of control group at all times, and the mean values differed statistically at moments M1 (S = 71.52 mmHg, C = 84.76 mmHg, p = 0.0356) and M5 (S = 71.38 mmHg, C = 85.52 mmHg, p = 0.0252). The IOP and color Doppler values of the external ophthalmic artery did not differ between tested groups. The dose of 10 mg of sildenafil citrate administered to healthy rabbits causes systemic vasodilation and consequently lower values of MAP and OPP. However, it does not induce changes in IOP and retrobulbar hemodynamics identifiable by color Doppler assessment of the external ophthalmic artery.

Reducing intraocular-pressure spike after intravitreal-bevacizumab injection with ocular decompression using a sterile cotton swab soaked in proparacaine 0.5%: A quasi-experimental study.

PubMed

Qureshi, Naveed A; Mansoor, Hassan; Ahmad, Sabihuddin; Zafar, Sarah; Asif, Muhammad

2016-01-01

The study was conducted to determine the effect of preinjection ocular decompression by a cotton swab soaked in local anesthetic on the immediate postinjection rise in intraocular pressure (IOP) after intravitreal bevacizumab (IVB). A nonrandomized, quasi-experimental interventional study was conducted at Al-Shifa Trust Eye Hospital, Pakistan, from August 1, 2013 to July 31, 2014. One hundred ( n = 100) patients receiving 0.05-mL IVB injection for the first time were assigned to two preinjection anesthetic methods: one with ocular decompression using a sterile cotton swab soaked in proparacaine 0.5%, and the other without ocular decompression using proparacaine 0.5% eyedrops. The IOP was recorded in the eye receiving IVB at three time intervals: Time 1 (preinjection), Time 2 (immediately after injection), and Time 3 (30 minutes after injection). There was a significant difference in the mean IOP change (between Time 1 and Time 2) for the group injected with ocular decompression [ M = 1.00, standard deviation (SD) = 1.47] and the group injected without ocular decompression ( M = 5.00, SD = 2.38; t (68) = 9.761, p < 0.001). There was also a significant difference in the mean IOP change (between Time 1 and Time 3) for the group injected with ocular decompression ( M = 0.428, SD = 1.58) and the group injected without ocular decompression ( M = 4.318, SD = 3.34; t (58) = 7.111, p < 0.001). Patients receiving IVB injections with ocular-decompression soaking in proparacaine 0.5% experience significantly lower postinjection IOP spike, and that too for a considerably shorter duration as compared to those receiving IVB without ocular decompression.

RES-loaded pegylated CS NPs: for efficient ocular delivery.

PubMed

Pandian, Saravanakumar; Jeevanesan, Vinoth; Ponnusamy, Chandrasekar; Natesan, Subramanian

2017-02-01

The objective of this study is to develop resveratrol (RES) loaded polyethylene glycols (PEGs) modified chitosan (CS) nanoparticles (NPs) by ionic gelation method for the treatment of glaucoma. While increasing the concentration of PEG, the particle size and polydispersity index of the formulations increased. Entrapment efficiency and RES loading (RL) of NPs decreased while increasing PEG concentration. The in vitro release of NPs showed an initial burst release of RES (45%) followed by controlled release. Osmolality of formulations revealed that the prepared NPs were iso-osmolar with the tear. Ocular tolerance of the NPs was evaluated using hen's egg test on the chorioallantoic membrane and it showed that the NPs were non-irritant. RES-loaded PEG-modified CS NPs shows an improved corneal permeation compared with RES dispersion. Fluorescein isothiocyanate loaded CS NPs accumulated on the surface of the cornea but the PEG-modified CS NPs crossed the cornea and reached retinal choroid. RES-loaded PEG-modified CS NPs reduced the intra-ocular pressure (IOP) by 4.3 ± 0.5 mmHg up to 8 h in normotensive rabbits. These results indicate that the developed NPs have efficient delivery of RES to the ocular tissues and reduce the IOP for the treatment of glaucoma.

Diurnal variations in axial length, choroidal thickness, intraocular pressure, and ocular biometrics.

PubMed

Chakraborty, Ranjay; Read, Scott A; Collins, Michael J

2011-07-11

To investigate the pattern of diurnal variations in axial length (AL), choroidal thickness, intraocular pressure (IOP), and ocular biometrics over 2 consecutive days. Measurements of ocular biometrics and IOP were collected for 30 young adult subjects (15 myopes, 15 emmetropes) at 10 different times over 2 consecutive days. Five sets of measurements were collected each day at approximately 3-hour intervals, with the first measurement taken at ~9 AM and final measurement at ~9 PM. AL underwent significant diurnal variation (P < 0.0001) that was consistently observed across the 2 measurement days. The longest AL was typically observed at the second measurement session (mean time, 12:26) and the shortest AL at the final session of each day (mean time, 21:06). The mean diurnal change in AL was 0.032 ± 0.018 mm. Choroidal thickness underwent significant diurnal variation (mean change, 0.029 ± 0.016 mm; P < 0.001) and varied approximately in antiphase to the AL changes. Significant diurnal variations were also found in vitreous chamber depth (VCD; mean change, 0.06 ± 0.029 mm; P < 0.0001) and IOP (mean change, 3.54 ± 0.84 mm Hg; P < 0.0001). A positive association was found between the variations of AL and IOP (r(2) = 0.17, P < 0.0001) and AL and VCD (r(2) = 0.31, P < 0.0001) and a negative association between AL and choroidal thickness (r(2) = 0.13, P < 0.0001). There were no significant differences in the magnitude and timing of diurnal variations associated with refractive error. Significant diurnal variations in AL, choroidal thickness, and IOP were consistently observed over 2 consecutive days of testing.

Flurbiprofen and intraocular pressure.

PubMed

Gieser, D K; Hodapp, E; Goldberg, I; Kass, M A; Becker, B

1981-07-01

Systemic or topical administration of corticosteroids may produce a rise in intraocular pressure (IOP). Nonsteroidal anti-inflammatory drugs (NSAI drugs) are alternate therapy for ocular inflammatory disease. Flurbiprofen, a new NSAI drug, was tested in double-masked fashion to delineate its effect on IOP. Flurbiprofen did not alter IOP in known high corticosteroid responders nor did it block corticosteroid-induced ocular hypertension.

Correlation between Age, Gender, Waist-Hip Ratio and Intra Ocular Pressure in Adult North Indian Population.

PubMed

Baisakhiya, Shikha; Singh, Surjit; Manjhi, Prafulla

2016-12-01

Intraocular pressure (IOP) is affected by various systemic and local factors. The significance of studying the factors affecting IOP is because of its association with potentially blinding condition known as glaucoma. Present study was conducted with the aim to find out the correlation between gender, age, Waist-Hip Ratio (WHR) and IOP. The study included 300 healthy individuals between 40-79years of age. The subjects were divided into 2 categories according to gender i.e., male and female. The subjects were divided into 4 categories according to age i.e., 40-49years, 50-59years, 60-69years and 70-79years. The subjects were divided into two groups according to Waist-hip ratio (WHR) as per WHO guidelines: WHR <0.9 and WHR >0.9 in males and WHR <0.85 and WHR >0.85 in females. IOP was recorded in each group using Goldmann Applanation tonometer and statistical comparisons were made to find correlation between gender, age, Waist-hip ratio and IOP. There was no statistically significant difference between IOP of males and females (p=0.235). The age and IOP were positively correlated with each other i.e., IOP increases with increasing age (r=0.511, p<0.001). Higher WHR is associated with significantly higher IOP in both the genders (males r =0.644, p<0.001; females r=0.794, p<0.001). There is no significant difference in IOP amongst males and females. Increasing age and higher WHR are risk factors for raised IOP.

Postural effects on intraocular pressure and ocular perfusion pressure in patients with non-arteritic anterior ischemic optic neuropathy.

PubMed

Yang, Jee Myung; Park, Sang Woo; Ji, Yong Sok; Kim, Jaeryung; Yoo, Chungkwon; Heo, Hwan

2017-04-20

To investigate postural effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with non-arteritic ischemic optic neuropathy (NAION). IOP and blood pressure (BP) were measured in 20 patients with unilateral NAION 10 min after changing to each of the following positions sequentially: sitting, supine, right lateral decubitus position (LDP), supine, left LDP, and supine. IOP was measured using a rebound tonometer and OPP was calculated using formulas based on mean BP. The dependent LDP (DLDP) was defined as the position when the eye of interest (affected or unaffected eye) was placed on the dependent side in the LDP. IOPs were significantly higher (P = 0.020) and OPPs were significantly lower (P = 0.041) in the affected eye compare with the unaffected eye, with the affected eye in DLDP. Compared with the mean IOP of the unaffected eyes, the mean IOP of the affected eyes increased significantly (+2.9 ± 4.4 versus +0.7 ± 3.1 mmHg, respectively; P = 0.003) and the mean OPP decreased significantly (-6.7 ± 9.4 versus -4.9 ± 8.0 mmHg, respectively; P = 0.022) after changing positions from supine to DLDP. In addition, changing position from supine to DLDP showed significantly larger absolute changes in IOP (4.13 ± 3.19 mmHg versus 2.51 ± 1.92 mmHg, respectively; P = 0.004) and OPP (9.86 ± 5.69 mmHg versus 7.50 ± 5.49 mmHg, respectively; P = 0.009) in the affected eye compared with the unaffected eye. In the affected eye, there was a significant positive correlation between absolute change in IOP and OPP when changing position from supine to DLDP (Rho = 0.512, P = 0.021). A postural change from supine to DLDP caused significant fluctuations in IOP and OPP of the affected eye, and may significantly increase IOP and decrease OPP. Posture-induced IOP changes may be a predisposing factor for NAION development.

Effect of sub-Tenon's and peribulbar anesthesia on intraocular pressure and ocular pulse amplitude.

PubMed

Pianka, P; Weintraub-Padova, H; Lazar, M; Geyer, O

2001-08-01

To compare the effect of peribulbar and sub-Tenon's anesthesia on intraocular pressure (IOP) and ocular pulse amplitude (OPA) in the injected eye and the fellow noninjected (control) eye. Tel Aviv Medical Center, Tel Aviv, Israel. This prospective study measured IOP and OPA at baseline and 1 and 10 minutes after administration of lidocaine anesthesia in 40 consecutive adult patients having elective cataract surgery. The IOP remained stable throughout the study with both modes of anesthesia. One minute after injection of the anesthetic agent, the OPA was significantly decreased in the injected eyes in both the sub-Tenon's (24%; P < .05) and peribulbar (25%; P < .05) groups. The decrease in the OPA in the sub-Tenon's group (14%; P < .05) was detectable after 10 minutes in the control eyes. In the peribulbar anesthesia group, the OPA in the control eyes increased significantly (9%; P < .05) 1 minute after injection of the anesthetic agent, returning to preinjection levels 10 minutes after the injection. The OPA in the eyes in which lidocaine was injected decreased significantly in both the sub-Tenon's and peribulbar groups. These findings have implications for the management of patients whose ocular circulation may be compromised.

Influence of Exercise Modality on Cerebral-Ocular Hemodynamics and Pressures

NASA Technical Reports Server (NTRS)

Scott, J.; Martin, D.; Crowell, B.; Goetchius, E.; Seponski, C.; Gonzales, R.; Matz, T.; Ploutz-Snyder, R.; Stenger, M.; Ploutz-Snyder, L.

2016-01-01

Background: Moderate and high intensity aerobic or resistance exercise has clearly identified benefits for cardiac, muscle, and bone health. However, the impact of such exercise - either as a mitigating or an exacerbating factor - on the development of the visual impairment and intracranial pressure syndrome (VIIP) is unknown. Accordingly, our aim was to characterize the effect of an acute bout of resistance (RE), moderate-intensity continuous (CE), and high-intensity interval exercise (IE) during a cephalad fluid shift on cerebral-ocular hemodynamics and pressures. Methods: 10 male subjects (36 plus or minus 9 years) completed 4 testing days in a 15 degree head-down tilt (HDT): (1) assessment of maximum volume of O (sub 2), (2) RE session (4 sets of 12 repetition maximum leg press exercise), (3) CE session (30 minutes of cycling at 60 percent maximum volume of O (sub 2)), and (4) IE session (4 by 4-minute intervals of exercise at 85 percent maximum volume of O (sub 2) with 3-minute active rest periods). During each session, blood flow (Vivid-e, GE Healthcare) in extracranial arteries (common carotid artery, CCA; internal carotid artery, ICA; external carotid artery, ECA and vertebral artery, VA), and mean blood flow velocity in middle cerebral artery (MCA), internal jugular pressure (IJP; VeinPress), and intraocular pressure (IOP; Icare PRO) were measured at rest, at the end of each resistance or interval set, and every 5 minutes during continuous exercise. Translaminar pressure gradient (TLPG) was estimated by subtracting IJP from IOP. Results: There were no differences across days in pre-exercise resting blood flows or pressures. IOP decreased slightly from HDT rest (20.2 plus or minus 2.3 millimeters of mercury) to exercise (RE: 19.2 plus or minus 2.8 millimeters of mercury; CE: 18.9 plus or minus 3.2 millimeters of mercury; IE: 20.1 plus or minus 2.8 millimeters of mercury), while IJP decreased during CE (31.6 plus or minus 9.5 millimeters of mercury) and RE

Impact of dehydration and fasting on intraocular pressure and corneal biomechanics measured by the Ocular Response Analyzer.

PubMed

Uysal, Betul Seher; Duru, Necati; Ozen, Umut; Arikan Yorgun, Mucella; Akcay, Emine; Caglayan, Mehtap; Cagil, Nurullah

2018-04-01

To investigate the effects of dehydration and fasting on the intraocular pressure (IOP) and corneal biomechanics during Ramadan in healthy subjects. A total of 36 healthy fasting male volunteers with a mean age of 32.7 ± 5.1 years (range 28-38 years) were enrolled in the study. A Reichert Ocular Response Analyzer (ORA) was used to measure the corneal resistance factor (CRF), corneal hysteresis (CH), Goldman-correlated IOP (IOPg), and corneal-compensated IOP (IOPcc), additionally IOP with Goldmann applanation tonometer (IOP-GAT) was taken. All measurements were recorded at 8:00 am and 4:00 p.m. during Ramadan and during a 1-month follow-up after Ramadan was over. Statistical analysis demonstrated no difference in the ORA measurements including CH, CRF, IOPcc, and IOPg; CCT and CV values between fasting and non-fasting periods or within a single day (diurnal changes). Nine volunteers (25% of total subjects) were excluded because eyedrops were believed to disrupt the Ramadan fast consequently IOP-GAT could not be measured from these subjects. No statistically significant difference was noted between IOP-GAT and IOPg measurements of twenty-seven subjects at the different periods and time points. Our results reveal that fasting during Ramadan does not profoundly affect corneal biomechanics and IOP values in healthy volunteers without ocular diseases such as glaucoma. When planning corneal refractive surgery and determining IOP, the ORA measurements can be done safely during a Ramadan fast. Moreover, ORA may be a better alternative for patients that refuse IOP measurement via GAT for examining the accuracy of IOP during fasting. Further studies are needed to better understand the role of these parameters on corneal disease and glaucoma during fasting.

Fixed combination of bimatoprost and timolol in patients with primary open-angle glaucoma or ocular hypertension with inadequate IOP adjustment

PubMed Central

Brief, Gerrett; Lammich, Tobias; Nagel, Edgar; Pfennigsdorf, Sabine; Spraul, Christoph W; Ho, Selwyn

2010-01-01

Objective To assess the efficacy and tolerability of a fixed combination of bimatoprost and timolol (BTFC) in a large patient sample in a clinical setting. Methods In this multicenter, observational, noncontrolled, open-label study, patients (n = 1862) with primary open-angle glaucoma or ocular hypertension were treated with BTFC. Assessments were made at baseline, six weeks, and three months. Results Prior to starting BTFC, 92.3% of patients were taking other ocular hypotensive medications. In the overall group at three months, mean intraocular pressure was reduced from baseline (21.7 ± 4.5 mmHg and 21.8 ± 4.9 mmHg for the right and left eye, respectively) to 16.1 ± 3.0 mmHg for each eye (P < 0.0001). The majority of patients (92%) reported no adverse events. The most commonly reported adverse events (in >1% of patients) were eye irritation, and ocular and conjunctival hyperemia. Adherence to treatment was generally better than (35.4%) or the same as (57.5%) with prior therapy. BTFC tolerability was rated as excellent or good by 92.3% of physicians and 85.8% of patients. Conclusions In a large group of patients with primary open-angle glaucoma or ocular hypertension, treatment with BTFC was associated with consistent reductions in IOP, improved adherence to treatment, and good tolerability. PMID:20957059

Effects of central corneal thickness on measurement of intra-ocular pressure in keratoconus and post-keratoplasty.

PubMed

Patel, S; McLaughlin, J M

1999-05-01

To measure and compare central corneal thickness (CT) and intraocular pressure (IOP) in keratoconus and post-keratoplasty subjects and examine the CT-IOP relationship. 22 keratoconus (category I: six female sixteen male, average age 27.0 range 12-47) and 19 post-keratoplasty (category II: ten female nine male average age 34.6 range 16-54) patients without other anterior segment conditions were recruited. Only one, non-contact lens wearing, eye of the patient was included for analysis. Cornea was anaesthetised with non-preserved 0.4% Benoxinate Hydrochloride. Using a randomised approach, CT was measured using a standard ultrasonic pachymeter. IOP was then measured using a standard Goldmann tonometer. At all times the tonometrist remained unaware of the corneal thickness values. The mean (+/- s.d.) values for CT and IOP respectively in the two categories were: (I), 445 (45) mu and 9.8 (2.3) mmHg, (II), 564(44) microns and 15.8 (3.9) mmHg. Differences between I and II for both CT and IOP were significant (t-test, p = 0.01). Within each category, a significant correlation between CT and IOP was not found. Pooling all pairs of data (n = 41) a significant relationship between CT and IOP was detected (r = 0.635, p = 0.0001). The results confirm the hypothesis that an eye with a thicker cornea tends to present with a higher measured IOP. In the management of keratoconus and other corneal surgical procedures, changes in CT will contribute to any apparent changes in measured IOP.

Long-term effect of BAK-free travoprost on ocular surface and intraocular pressure in glaucoma patients after transition from latanoprost.

PubMed

Aihara, Makoto; Otani, Shin-ichiro; Kozaki, Jun; Unoki, Kazuhiko; Takeuchi, Masamitsu; Minami, Keiichiro; Miyata, Kazunori

2012-01-01

To assess the efficacy and tolerability of benzalkonium chloride (BAK)-free travoprost after transition from BAK-preserved latanoprost. This was a prospective, open-label, multicenter study in patients with open-angle glaucoma or ocular hypertension who had been treated with latanoprost monotherapy for at least 3 months. The main outcome measures were superficial punctate keratopathy (SPK), hyperemia, and intraocular pressure (IOP). At baseline, 1, 3, and 12 months, hyperemia, SPK, and IOP were consecutively assessed. Hyperemia was assessed using a 4-grade scale. SPK was assessed by fluorescence staining observed by Area-Density classification. The IOP was measured by Goldmann applanation tonometry. One hundred and fourteen patients participated in this study. Twenty-eight patients discontinued medications by 1 month. Sixty-seven patients completed the study. Transition from latanoprost to BAK-free travoprost showed no significant effect on hyperemia at 1 month, but showed significant decreases at 3 and 12 months compared with baseline (P<0.05). The prevalence of SPK, especially its severity score, at all points were significantly reduced compared with baseline (P<0.05). The IOP at baseline and at 12 months after transition was 14.9±3.4 and 14.3±3.3 mm Hg, indicating a significant reduction after the change in regimen compared with baseline (P<0.05). Treatment for 12 months with BAK-free travoprost after BAK-preserved latanoprost resulted in fewer ocular surface complications, as indicated by the reduced prevalence of SPK and decreased hyperemia, and no clinically relevant changes in IOP. BAK-free travoprost may have beneficial effects on the ocular surface while showing IOP-lowering efficacy comparable with BAK-preserved eye drops.

Trabecular micro-bypass stent implantation during small-incision cataract surgery for open-angle glaucoma or ocular hypertension: Long-term results.

PubMed

Neuhann, Tobias H

2015-12-01

To evaluate long-term safety and efficacy of iStent trabecular micro-bypass stent implantation during cataract surgery in patients with primary open-angle, pseudo-exfoliation glaucoma, ocular hypertension, or secondary or post-traumatic glaucoma. AaM Augenklinik am Marienplatz, Munich, Germany. Prospective, open-label, non-randomized study. Preoperative and postoperative evaluations included intra-ocular pressure (IOP), topical ocular hypotensive medication use, cup/disc ratio, corrected-distance visual acuity (CDVA), complications, and adverse events. A single trabecular micro-bypass stent was implanted through the same temporal, limbal incision used for cataract surgery via phacoemulsification in a consecutive series of 62 eyes of 43 patients. To date, a total of 41 eyes have been followed for 3 years postoperatively, whereas long-term postoperative follow-up on the remaining patients is ongoing. Mean preoperative IOP was 24.1 ± 6.9 mm Hg on a mean of 1.8 medications (±0.9). Analyses of eyes with no secondary surgical intervention showed mean IOP reduction to 14.8 ± 4.2 mm Hg at 12 months (n = 61), 14.5 ± 2.2 mm Hg at 24 months (n = 42), and 14.9 ± 2.3 mm Hg at 36 months (n = 39). Medications were eliminated in 74% of eyes at 36 months. Five eyes, 4 with previous glaucoma surgeries and 1 with pseudo-exfoliation syndrome, required additional glaucoma surgery after stent implantation. No intra-operative or postoperative complications typically seen with conventional glaucoma surgeries occurred after stent implantation. At 36 months, CDVA was 20/40 or better in 38 eyes (93%). Trabecular micro-bypass stent implantation during cataract surgery was safe and effective in patients with ocular hypertension or glaucoma as measured by a sustained reduction in IOP and medication use and an excellent safety profile through 3 years after surgery. Dr. Neuhann has no financial or proprietary interest in any material or method mentioned. Glaukos Corp. provided editorial

Effect of acute intraocular pressure elevation on the minimum rim width in normal, ocular hypertensive and glaucoma eyes.

PubMed

Sharma, Sourabh; Tun, Tin A; Baskaran, Mani; Atalay, Eray; Thakku, Sri Gowtham; Liang, Zhang; Milea, Dan; Strouthidis, Nicholas G; Aung, Tin; Girard, Michael Ja

2018-01-01

To estimate and compare changes in the Bruch's membrane opening-minimum rim width (BMO-MRW) and area in normal, ocular hypertensive and glaucoma eyes following acute elevations in intraocular pressure (IOP). The optic nerve heads (ONHs) of 104 subjects (31 normals, 20 ocular hypertension (OHT) and 53 with primary glaucoma) were imaged using Spectral-domain optical coherence tomography (OCT; Spectralis, Heidelberg Engineering, Germany). IOP was raised twice by applying a force (0.64 n then 0.9 n) to the anterior sclera using an ophthalmo-dynamometer. After each IOP increment, IOP was held constant, measured with a Tonopen (AVIA applanation tonometer, Reichert, Depew, New York, USA), and ONH was rescanned with OCT. In each OCT volume, BMO-MRW and area were calculated and at each IOP increment. The baseline MRW was significantly smaller in glaucoma subjects (174.3±54.3 µm) compared with normal (287.4±42.2 µm, p<0.001) and OHT subjects (255.4±45.3 µm, p<0.001). MRW of glaucoma subjects was significantly thinner at the first and second IOP elevations than that at baseline (both p<0.01), but no significant change was noted in normal and OHT subjects. There was no significant change of BMO area at acute IOP elevations from baseline in all diagnoses (all p>0.05). Acute IOP elevation leads to compression of the nerve fibre layers of neuroretinal rim in glaucoma subjects only without changing ONH size. This suggests that the neural and connective tissues at ONH level in glaucoma subjects are more susceptible to acute IOP episodes than OHT or normal controls. © 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.

Comparison of choroidal and optic nerve head blood flow regulation during changes in ocular perfusion pressure.

PubMed

Schmidl, Doreen; Boltz, Agnes; Kaya, Semira; Werkmeister, Rene; Dragostinoff, Nikolaus; Lasta, Michael; Polska, Elzbieta; Garhöfer, Gerhard; Schmetterer, Leopold

2012-07-01

We compared the response of choroidal and optic nerve head blood flow (ChBF, ONHBF) in response to an increase in ocular perfusion pressure (OPP) during isometric exercise and during a decrease in OPP during an artificial increase in intraocular pressure (IOP). We included 96 healthy subjects in our study. In 48 subjects OPP was increased by 6 minutes of squatting, and either ONHBF (n = 24) or ChBF (n = 24) was measured continuously. In 48 other healthy subjects either ONHBF (n = 24) or ChBF (n = 24) was measured continuously during a period of artificial increase in IOP using a suction cup. All blood flow measurements were done using laser Doppler flowmetry. During all experiments the response in blood flow was less pronounced than the response in OPP, indicating for flow regulation. During isometric exercise ChBF regulated better than ONHBF (P = 0.023). During artificial IOP increase ONHBF regulated better than ChBF (P = 0.001). Inter-individual variability in blood flow responses was high. During squatting ONHBF decreased considerably below baseline ONHBF when OPP fluctuated in 3 subjects, although OPP still was much higher than at baseline. This phenomenon was not observed in the choroid. Our data indicate that regulation of ChBF and ONHBF during changes in OPP is different and complex. In some subjects performing squatting, considerable ONHBF reductions were observed during OPP fluctuations, although OPP still was high. Whether this predisposes to ocular disease remains unclear.

Role of NO in the control of choroidal blood flow during a decrease in ocular perfusion pressure.

PubMed

Simader, Christian; Lung, Solveig; Weigert, Günther; Kolodjaschna, Julia; Fuchsjäger-Mayrl, Gabriele; Schmetterer, Leopold; Polska, Elzbieta

2009-01-01

The study was conducted to investigate whether the L-arginine/nitric oxide system plays a role in choroidal blood flow (ChBF) regulation during a decrease in ocular perfusion pressure (OPP). Experiments were performed on 3 days in a randomized double-masked, placebo-controlled, three-way crossover design. On different study days, subjects received intravenous infusions of N(G)-monomethyl-L-arginine (L-NMMA), phenylephrine, or placebo. Intraocular pressure was raised in stepwise increments using the suction cup Choroidal blood flow (ChBF, laser Doppler flowmetry), mean arterial blood pressure (MAP), and IOP were assessed. Ocular perfusion pressure was calculated as OPP = 23(MAP - IOP). For correlation analysis all OPP/ChBF data pairs from all subjects were pooled independent of time point of measurement. Then, the pooled data were sorted according to OPP, and correlation analyses were performed. L-NMMA and phenylephrine increased resting OPP by +17% +/- 18% and +14% +/- 21%, respectively (P < 0.05). L-NMMA reduced resting ChBF by -21% +/- 17% (P < 0.05). The relative decrease in OPP during suction cup application was comparable with all drugs administered. The decrease in OPP was paralleled by a significant decrease in ChBF (maximum between -39% and -47%), which was less pronounced, however, than the decrease in OPP (maximum between -69% and -74%). Neither placebo nor L-NMMA, nor phenylephrine, influenced the OPP/ChBF relationship. The data confirm previously published observations that the choroid shows some regulatory capacity during reduced OPP. The L-arginine/nitric oxide-system plays a role in the maintenance of basal vascular tone but seems not to be involved in the choroidal vasodilator response when IOP is increased.

[Ocular hypotensive effect of alpha-adrenoceptor agonist and antagonist in the conscious pigmented rabbit].

PubMed

Moriwaki, Y; Iizuka, T; Nakamura, A; Nakata, K; Masaoka, Y; Ueda, T; Koide, R; Inatomi, M; Fukado, Y; Uchida, E

1992-02-01

It has been reported that some of the topically-used antiglaucomatics have a central ocular hypotensive effect. In this study, the influence of topical and intracerebroventricular (i.c.v.) administration of phenylephrine, clonidine, guanfacine, prazosin, yohimbine on the intraocular pressure (IOP) was investigated in the rabbit. Male pigmented rabbits were used throughout the experiments. For measurement of IOP, an applanation pneumatonograph was used. By unilateral topical administration of phenylephrine, an increase in IOP in the eye in which instillation was performed was observed. On the other hand, a slight decrease in IOP was observed by similar treatment of prazosin and yohimbine. No significant change of IOP in the contralateral eye was observed with these drugs. On the contrary, unilateral topical administration of clonidine or guanfacine decreased the IOP of both eyes. Furthermore, the decrease of IOP was more remarkable in the contralateral eye compared to the eye which received instillation. The IOP of both eyes was decreased in a dose-related fashion by i.c.v. administration of clonidine or guanfacine. The ocular hypotensive effects of clonidine were diminished by the pretreatment by i.c.v. administration with yohimbine. These results suggest that the ocular hypotensive effect of clonidine and guanfacine is due to their alpha 2-adrenoceptor stimulation in the central nervous system.

Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT.

PubMed

Zhi, Zhongwei; Cepurna, William; Johnson, Elaine; Jayaram, Hari; Morrison, John; Wang, Ruikang K

2015-09-01

To determine if retinal capillary filling is preserved in the face of acutely elevated intraocular pressure (IOP) in anesthetized rats, despite a reduction in total retinal blood flow (RBF), using optical microangiography/optical coherence tomography (OMAG/OCT). OMAG provided the capability of depth-resolved imaging of the retinal microvasculature down to the capillary level. Doppler OCT was applied to measure the total RBF using an enface integration approach. The microvascular pattern, capillary density, and total RBF were monitored in vivo as the IOP was increased from 10 to 100mmHg in 10mmHg intervals and returned back to 10mmHg. In animals with mean arterial pressure (MAP) of 102±4mmHg (n=10), when IOP was increased from 0 to 100mmHg, the capillary density remained at or above 80% of baseline for the IOP up to 60mmHg [or ocular perfusion pressure (OPP) at 40mmHg]. This was then decreased, achieving 60% of baseline at IOP 70mmHg and OPP of 30mmHg. Total RBF was unaffected by moderate increases in IOP up to 30mmHg, beyond which total RBF decreased linearly, reaching 50% of baseline at IOP 60mmHg and OPP 40mmHg. Both capillary density and total RBF were totally extinguished at 100mmHg, but fully recovered when IOP returned to baseline. By comparison, a separate group of animals with lower MAP (mean=75±6mmHg, n=7) demonstrated comparable decreases in both capillary filling and total RBF at IOPs that were 20mmHg lower than in the initial group. Both were totally extinguished at 80mmHg, but fully recovered when IOP returned to baseline. Relationships of both parameters to OPP were unchanged. Retinal capillary filling and total RBF responses to IOP elevation can be monitored non-invasively by OMAG/OCT and both are influenced by OPP. Retinal capillary filling was relatively preserved down to a perfusion pressure of 40mmHg, despite a linear reduction in total RBF. Copyright © 2015 Elsevier Inc. All rights reserved.

Noncontact optical coherence elastography of the posterior porcine sclera in situ as a function of IOP

NASA Astrophysics Data System (ADS)

Singh, Manmohan; Nair, Achuth; Aglyamov, Salavat R.; Wu, Chen; Han, Zhaolong; Lafon, Ericka; Larin, Kirill V.

2017-02-01

Recent work has shown that the biomechanical properties of tissues in the posterior eye have are critical for understanding the etiology and progression of ocular diseases. For instance, the primary risk for glaucoma is an elevated intraocular pressure (IOP). Weak tissues will deform under the large pressure, causing damage to vital tissues. In addition, scleral elasticity can influence the shape of the eye-globe, altering the axial length. In this work, we utilize a noncontact form of optical coherence elastography (OCE) to quantify the spatial distribution of biomechanical properties of the optic nerve, its surrounding tissues, and posterior sclera on the exterior of in situ porcine eyes in the whole eyeglobe configuration. The OCE measurements were taken at various IOPs to evaluate the biomechanical properties of the tissues as a function of IOP. The air-pulse induced dynamic response of the tissues was linked to Young's modulus by a simple kinematic equation by quantified the damped natural frequency (DNF). The results show that the posterior sclera is not as stiff as the optic nerve and its surrounding tissues ( 460 Hz and 894 Hz at 10 mmHg IOP, respectively). Moreover, the scleral stiffness was generally unaffected by IOP ( 460 Hz at 10 mmHg IOP as compared to 516 Hz at 20 mmHg), whereas the optic nerve and its surrounding tissues stiffened as IOP was increased ( 894 Hz at 10 mmHg to 1221 Hz at 20 mmHg).

Arterial and intraocular pressure changes after a single-session hot-water immersion.

PubMed

Findikoglu, Gulin; Cetin, Ebru Nevin; Sarsan, Ayse; Senol, Hande; Yildirim, Cem; Ardic, Fusun

2015-01-01

The aim of this study is to investigate the effect of head-out hot-water immersion on the intraocular pressure (IOP) of healthy subjects and investigate whether this intervention alters cardiovascular and microcirculatory responses. METHODs: 16 male and 18 female healthy young adults were immersed in 39 degrees C water up to shoulder level for 20 minutes. Blood pressure (BP), heart rate (HR) and IOP were measured pre-immersion, post-immersion and five minutes after immersion on the same day. Tono-Pen was used to measure IOP. Mean arterial blood pressure (MAP), systolic pressure rate product (S-PRP), diastolic pressure rate product (D-PRP), pulse pressure (PP), mean ocular perfusion pressure (mean-OPP), systolic ocular perfusion pressure (S-OPP) and diastolic ocular perfusion pressure (D-OPP) were calculated. Systolic BP (SBP), diastolic BP (DBP), MAP, IOP, S-OPP, D-OPP and mean-OPP decreased; HR increased five minutes after immersion in the pool and post-immersion out of the pool significantly, compared to pre-immersion data (p < 0.05). HR, S-PRP and D-PRP measured five minutes after immersion were significantly higher from post-immersion (p < 0.05). PP and S-OPP were significantly different five minutes after immersion compared to pre-immersion. There was no statistically significant correlation between IOP and SBP, DBP, MAP, S-PRP, D-PRP, PP, S-OPP, D-OPP, or mean-OPP (p > 0.05). Physiological hemodynamic response to single head-out hot-water immersion caused a statistically significant decrease in IOP. Preliminary results could help to clarify vascular reactions and IOP changes during hot-water immersion that might be potentially therapeutic in glaucoma patients.

Effects of a beta-adrenergic blocking agent timolol on intra ocular pressure responses induced by stimulation of cervical sympathetic nerve in the cat.

PubMed

Naito, A; Izumi, H; Karita, K; Tamai, M

2001-12-01

We clarified whether the intraocular pressure (IOP) response elicited by stimulation of the cervical sympathetic nerve (CSN) is influenced by changes in the baseline of IOP level and by beta-adrenergic blockade. The CSN was stimulated electrically for 30 seconds (10 V, 0.1-100 Hz, 2 milliseconds pulse duration) in urethane (100 mg/kg i.v.)-chloralose (50 mg/kg i.v.)-anesthetized, paralyzed cats. The IOP was monitored manometrically, and a controlled saline infusion was delivered into the anterior chamber to gradually increase IOP. CSN stimulation was delivered at the various baseline IOP levels so obtained. When required, a beta-adrenergic blocker timolol (2%) was delivered into the conjunctival cul-de-sac. The normal IOP in our cats was 25+/-3 mmHg. This value decreased transiently on CSN stimulation. The amplitude of this IOP response depended on stimulus frequency and the pre-stimulus baseline IOP level. Topical administration of timolol increased the IOP response to CSN stimulation at a given baseline level. These results suggest that beta-adrenergic blockade increases the alpha-adrenergic mediated-IOP reduction elicited by CSN stimulation at given baseline IOP level.

Intraocular pressure and biomechanical corneal properties measure by ocular response analyser in patients with primary congenital glaucoma.

PubMed

Perucho-González, Lucía; Martínez de la Casa, Jose María; Morales-Fernández, Laura; Bañeros-Rojas, Paula; Saenz-Francés, Federico; García-Feijoó, Julían

2016-08-01

To measure the differences in corneal hysteresis (CH) and corneal resistance factor (CRF) in primary congenital glaucoma (PCG) and in control subjects using ocular response analyser (ORA) and also to compare intraocular pressure (IOP) measurements given by ORA against IOP given by Perkins tonometer, a handheld version of Goldman applanation tonometer (GAT), to determine correlation. One hundred and eighteen eyes of 78 patients with PCG (group I) and 103 eyes of 53 controls (group II) were evaluated using ORA. In all participants, IOP was measured using the Perkins tonometer. The ORA device uses applanation pressure peaks to generate the corneal-compensated IOP (IOPcc), which is reportedly independent of corneal thickness, and the measurement of Goldman-correlated IOP (IOPg), which is influenced by corneal thickness. The measures in group I were as follows: IOPcc 20.92 ± 5.33; IOPg 18.87 ± 6.67; CH 8.51 ± 2.25; CRF 9.85 ± 3.03; and IOP measured by Goldman 18.32 ± 5.13. The measures in group II were as follows: IOPcc 14.33 ± 2.91; IOPg 14.77 ± 3.00; CH 11.37 ± 1.61; CRF 11.02 ± 1.74; and IOP measured by Goldman 13.74 ± 2.42. The differences of all parameters compared between both groups were statistically significant (p < 0.001 for CH and for all IOP measures and p = 0.001 for CRF). The values of IOPcc, IOPg and IOP measured with Goldman were higher in group I than the values in group II. However, CH and CRF values were lower in group I. A decrease in CH and CRF has been observed in patients with PCG compared to controls. Future research should assess how these parameters are modified in PCG and whether they could provide more information about progression. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Duration of IOP reduction with travoprost BAK-free solution.

PubMed

Gross, Ronald L; Peace, James H; Smith, Stephen E; Walters, Thomas R; Dubiner, Harvey B; Weiss, Mark J; Ochsner, Katherine I

2008-01-01

To compare the duration of action of travoprost ophthalmic solution 0.004% (Travatan Z) formulated without benzalkonium chloride (BAK) to travoprost ophthalmic solution 0.004% formulated with BAK (Travatan). This was a prospective, randomized, double-masked study. Patients with open-angle glaucoma or ocular hypertension were randomized to receive 2 weeks of once-daily therapy with travoprost BAK-free or travoprost with BAK. Patients received the last dose of medication on day 13 and then intraocular pressure (IOP) was assessed every 12 hours for 60 hours. Statistical analysis included change in IOP from baseline for each group and comparison of mean IOP between groups. Of the 109 patients enrolled, 106 patients completed the study. Untreated mean baseline IOP at 8 AM was 26.9 mm Hg in the travoprost BAK-free group and 27.1 mm Hg in the travoprost with BAK group. At 12, 24, 36, 48, and 60 hours after the last dose, mean IOP in the travoprost BAK-free group was 18.7, 17.2, 19.5, 18.7, and 20.8 mm Hg, respectively; whereas mean IOP in the travoprost with BAK group was 18.5, 16.8, 19.7, 18.0, and 20.8 mm Hg, respectively. Mean IOP at all time points after the last dose of medication was >6 mm Hg lower than the 8 AM baseline in both groups. Between-group differences were within +/-0.6 mm Hg at all postdose time points. There were no statistically significant differences between the 2 treatment groups at baseline or at any postdose time point. Drug-related side effects were uncommon, mild in intensity, and comparable between groups. Travoprost without BAK has similar IOP-lowering efficacy and safety compared with travoprost preserved with BAK. Both formulations of travoprost have a prolonged duration of action, with statistically and clinically significant reductions from baseline persisting up to 60 hours after the last dose.

Intraocular pressure values obtained by ocular response analyzer, dynamic contour tonometry, and goldmann tonometry in keratokonic corneas.

PubMed

Bayer, Atilla; Sahin, Afsun; Hürmeriç, Volkan; Ozge, Gökhan

2010-01-01

To determine the agreement between dynamic contour tonometer (DCT), Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA) in keratoconic corneas and to find out the effect of corneal biomechanics on intraocular pressure (IOP) measurements obtained by these devices. IOP was measured with the ORA, DCT, and GAT in random order in 120 eyes of 61 keratoconus patients. Central corneal thickness (CCT) and keratometry were measured after all IOP determinations had been made. The mean IOP measurement by the ORA and DCT was compared with the measurement by the GAT, using Student t test. Bland-Altman analysis was performed to assess the clinical agreement between these methods. The effect of corneal hysteresis (CH), corneal resistance factor (CRF), and CCT on measured IOP was explored by multiple backward stepwise linear regression analysis. The mean±SD patient age was 30.6±11.2 years. The mean±SD IOP measurement obtained with GAT, ORA Goldmann-correlated IOP (IOPg), ORA corneal-compensated IOP (IOPcc), and DCT was 10.96±2.8, 10.23±3.5, 14.65±2.8, and 15.42±2.7 mm Hg, respectively. The mean±SD CCT was 464.08±58.4 microns. The mean difference between IOPcc and GAT (P<0.0001), IOPcc and DCT (P<0.001), GAT and DCT (P<0.0001), IOPg and GAT (P<0.002), and IOPg and DCT (P<0.0001), was highly statistically significant. In multivariable regression analysis, DCT IOP and GAT IOP measurements were significantly associated with CH and CRF (P<0.0001 for both). DCT seemed to be affected by CH and CRF, and the IOP values tended to be higher when compared with GAT. ORA-measured IOPcc was found to be independent of CCT and suitable in comparison to the DCT in keratoconic eyes.

Fundus autofluorescence imaging in an ocular screening program.

PubMed

Kolomeyer, A M; Nayak, N V; Szirth, B C; Khouri, A S

2012-01-01

Purpose. To describe integration of fundus autofluorescence (FAF) imaging into an ocular screening program. Methods. Fifty consecutive screening participants were included in this prospective pilot imaging study. Color and FAF (530/640 nm exciter/barrier filters) images were obtained with a 15.1MP Canon nonmydriatic hybrid camera. A clinician evaluated the images on site to determine need for referral. Visual acuity (VA), intraocular pressure (IOP), and ocular pathology detected by color fundus and FAF imaging modalities were recorded. Results. Mean ± SD age was 47.4 ± 17.3 years. Fifty-two percent were female and 58% African American. Twenty-seven percent had a comprehensive ocular examination within the past year. Mean VA was 20/39 in the right eye and 20/40 in the left eye. Mean IOP was 15 mmHg bilaterally. Positive color and/or FAF findings were identified in nine (18%) individuals with diabetic retinopathy or macular edema (n = 4), focal RPE defects (n = 2), age-related macular degeneration (n = 1), central serous retinopathy (n = 1), and ocular trauma (n = 1). Conclusions. FAF was successfully integrated in our ocular screening program and aided in the identification of ocular pathology. Larger studies examining the utility of this technology in screening programs may be warranted.

Fundus Autofluorescence Imaging in an Ocular Screening Program

PubMed Central

Kolomeyer, A. M.; Nayak, N. V.; Szirth, B. C.; Khouri, A. S.

2012-01-01

Purpose. To describe integration of fundus autofluorescence (FAF) imaging into an ocular screening program. Methods. Fifty consecutive screening participants were included in this prospective pilot imaging study. Color and FAF (530/640 nm exciter/barrier filters) images were obtained with a 15.1MP Canon nonmydriatic hybrid camera. A clinician evaluated the images on site to determine need for referral. Visual acuity (VA), intraocular pressure (IOP), and ocular pathology detected by color fundus and FAF imaging modalities were recorded. Results. Mean ± SD age was 47.4 ± 17.3 years. Fifty-two percent were female and 58% African American. Twenty-seven percent had a comprehensive ocular examination within the past year. Mean VA was 20/39 in the right eye and 20/40 in the left eye. Mean IOP was 15 mmHg bilaterally. Positive color and/or FAF findings were identified in nine (18%) individuals with diabetic retinopathy or macular edema (n = 4), focal RPE defects (n = 2), age-related macular degeneration (n = 1), central serous retinopathy (n = 1), and ocular trauma (n = 1). Conclusions. FAF was successfully integrated in our ocular screening program and aided in the identification of ocular pathology. Larger studies examining the utility of this technology in screening programs may be warranted. PMID:23316224

Mechanism - based translational pharmacokinetic - pharmacodynamic model to predict intraocular pressure lowering effect of drugs in patients with glaucoma or ocular hypertension.

PubMed

Durairaj, Chandrasekar; Shen, Jie; Cherukury, Madhu

2014-08-01

To develop a mechanism based translational pharmacokinetic-pharmacodynamic (PKPD) model in preclinical species and to predict the intraocular pressure (IOP) following drug treatment in patients with glaucoma or ocular hypertension (OHT). Baseline diurnal IOP of normotensive albino rabbits, beagle dogs and patients with glaucoma or OHT was collected from literature. In addition, diurnal IOP of patients treated with brimonidine or Xalatan® were also obtained from literature. Healthy normotensive New Zealand rabbits were topically treated with a single drop of 0.15% brimonidine tartrate and normotensive beagle dogs were treated with a single drop of Xalatan®. At pre-determined time intervals, IOP was measured and aqueous humor samples were obtained from a satellite group of animals. Population based PKPD modeling was performed to describe the IOP data and the chosen model was extended to predict the IOP in patients. Baseline IOP clearly depicts a distinctive circadian rhythm in rabbits versus human. An aqueous humor dynamics based physiological model was developed to describe the baseline diurnal IOP across species. Model was extended to incorporate the effect of drug administration on baseline IOP in rabbits and dogs. The translational model with substituted human aqueous humor dynamic parameters predicted IOP in patients following drug treatment. A physiology based mechanistic PKPD model was developed to describe the baseline and post-treatment IOP in animals. The preclinical PKPD model was successfully translated to predict IOP in patients with glaucoma or OHT and can be applied in assisting dose and treatment selection and predicting outcome of glaucoma clinical trials.

Non-invasive measurement of choroidal volume change and ocular rigidity through automated segmentation of high-speed OCT imaging

PubMed Central

Beaton, L.; Mazzaferri, J.; Lalonde, F.; Hidalgo-Aguirre, M.; Descovich, D.; Lesk, M. R.; Costantino, S.

2015-01-01

We have developed a novel optical approach to determine pulsatile ocular volume changes using automated segmentation of the choroid, which, together with Dynamic Contour Tonometry (DCT) measurements of intraocular pressure (IOP), allows estimation of the ocular rigidity (OR) coefficient. Spectral Domain Optical Coherence Tomography (OCT) videos were acquired with Enhanced Depth Imaging (EDI) at 7Hz during ~50 seconds at the fundus. A novel segmentation algorithm based on graph search with an edge-probability weighting scheme was developed to measure choroidal thickness (CT) at each frame. Global ocular volume fluctuations were derived from frame-to-frame CT variations using an approximate eye model. Immediately after imaging, IOP and ocular pulse amplitude (OPA) were measured using DCT. OR was calculated from these peak pressure and volume changes. Our automated segmentation algorithm provides the first non-invasive method for determining ocular volume change due to pulsatile choroidal filling, and the estimation of the OR constant. Future applications of this method offer an important avenue to understanding the biomechanical basis of ocular pathophysiology. PMID:26137373

Ocular pulsation correlates with ocular tension: the choroid as piston for an aqueous pump?

PubMed

Phillips, C I; Tsukahara, S; Hosaka, O; Adams, W

1992-01-01

In 26 random out-patients, including 13 treated glaucoma patients and ocular hypertensives, the higher the ocular tension, the greater the pulse amplitude, by Alcon pneumotonometry, at a statistically significant level. In a single untreated hypertensive, when 2-hourly pneumotonometry was done for 24 h, the correlation was similar and significant. The higher the diastolic blood pressure, the higher the ocular pulsation, also significantly. Pulsation is suggested to be a pump, the choroid being the piston, contributing (1) to an increase in the outflow of aqueous humour and (2) to a homeostatic mechanism contributing to normalization of the intra-ocular pressure, wherein pulsation increases or decreases, as the intraocular pressure increases or decreases, respectively.

Latanoprostene Bunod Ophthalmic Solution 0.024%: A Review in Open-Angle Glaucoma and Ocular Hypertension.

PubMed

Hoy, Sheridan M

2018-05-14

Latanoprostene bunod ophthalmic solution 0.024% (hereafter referred to as latanoprostene bunod 0.024%) [Vyzulta™] is a nitric oxide (NO)-donating prostaglandin F 2α analogue approved in the USA for the reduction of intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) or ocular hypertension. It is thought to lower IOP by increasing aqueous humour outflow through the uveoscleral pathway (mediated by latanoprost acid) and increasing the facility of aqueous humour outflow through the trabecular meshwork pathway (mediated by NO). Results from two multinational, phase III studies (APOLLO and LUNAR) and a pooled analysis of these studies demonstrated the noninferiority of latanoprostene bunod 0.024% to timolol ophthalmic solution 0.5% (hereafter referred to as timolol 0.5%) in terms of IOP-lowering efficacy over 3 months in patients with OAG or ocular hypertension, with the superiority of latanoprostene bunod 0.024% over timolol 0.5% subsequently demonstrated in APOLLO and the pooled analysis. Moreover, there was no apparent loss of IOP-lowering effect in subsequent safety extension periods of up to 9 months. The IOP-lowering efficacy seen in APOLLO and LUNAR was confirmed in a phase III study (JUPITER) in Japanese patients, with IOP reductions observed early (week 4) and maintained over the longer-term (12 months). Latanoprostene bunod 0.024% was well tolerated over up to 12 months in these studies, with most ocular treatment-emergent adverse events (TEAEs) being mild to moderate in severity. Thus, current evidence indicates once-daily latanoprostene bunod 0.024% is an effective and well tolerated treatment option for the reduction of IOP in adults with OAG or ocular hypertension.

Randomized trial of brinzolamide/brimonidine versus brinzolamide plus brimonidine for open-angle glaucoma or ocular hypertension.

PubMed

Gandolfi, Stefano A; Lim, John; Sanseau, Ana Cristina; Parra Restrepo, Juan Camilo; Hamacher, Thomas

2014-12-01

Fixed-combination intraocular pressure (IOP)-lowering medications simplify treatment regimens for patients requiring 2 ocular hypotensive agents to maintain sufficiently low IOP. The aim of this study was to evaluate the safety and efficacy of fixed-combination brinzolamide 1%/brimonidine 0.2% (BBFC) versus concomitant administration of brinzolamide 1% plus brimonidine 0.2% (BRINZ + BRIM) in patients with open-angle glaucoma or ocular hypertension. This was a prospective, phase 3, multicenter, double-masked, 6-month trial. Patients who had insufficient IOP control with monotherapy or who were receiving 2 IOP-lowering medications were randomized 1:1 to receive twice-daily BBFC or BRINZ + BRIM. IOP was assessed at 9 a.m. and 11 a.m. during week 2, week 6, month 3, and month 6 visits. The primary efficacy endpoint was mean diurnal IOP change from baseline to month 3; noninferiority was concluded if the upper limit of the 95% CI of the between-group difference was <1.5 mmHg. Supportive endpoints included mean IOP, IOP change from baseline, and percentage of patients with IOP <18 mmHg. Adverse events were recorded. The mean diurnal IOP change from baseline with BBFC (least squares mean ± standard error -8.5 ± 0.16 mmHg) was noninferior to that with BRINZ + BRIM (-8.3 ± 0.16 mmHg; mean difference -0.1 mmHg; 95% CI -0.5 to 0.2 mmHg). The upper limits of the 95% CIs were <1.5 mmHg at all time points. Decreases from baseline >8 mmHg were observed for least squares mean diurnal IOP in both groups as early as week 2 and continued to the end of the study. The results of all other supportive endpoints were similar to the primary efficacy endpoint. The most common ocular adverse drug reactions were hyperemia of the eye (reported as ocular or conjunctival hyperemia), visual disturbances, ocular allergic reactions, and ocular discomfort. Common systemic adverse drug reactions included dysgeusia, oral dryness, and fatigue/drowsiness. Brinzolamide 1

Cationic solid lipid nanoparticles enhance ocular hypotensive effect of melatonin in rabbit.

PubMed

Leonardi, Antonio; Bucolo, Claudio; Drago, Filippo; Salomone, Salvatore; Pignatello, Rosario

2015-01-15

The study was aimed at evaluating whether the ocular hypotensive effect of melatonin (MEL) was enhanced by its encapsulation in cationic solid lipid nanoparticles (cSLN), as well as at determining the tolerability of these formulations on the ocular surface. MEL was loaded in cSLN that had already been shown to be suitable for ophthalmic use. The formulations were prepared using Softisan(®) 100 as the main lipid matrix, with the presence of either stearic (SA) or palmitic acid (PA) as lipid modifiers. A fixed positive charge was provided by the addition of a cationic lipid (didecyldimethylammonium bromide). The ocular hypotensive effect was evaluated by measuring the intraocular pressure (IOP) during 24h in albino rabbits. MEL elicited a significant (p<0.01) IOP reduction in rabbit eye. All the formulations tested in vivo demonstrated a good tolerability. The nanocarrier containing SA was the most effective in terms of IOP reduction (maximum IOP reduction: -7 mmHg), and its effect lasted approximately 24h. The experimental data indicate that the new formulations based on cSLN loaded with MEL represent a potent anti-glaucoma treatment with a safe profile, warranting further clinical evaluation of the proposed nanotechnological strategy. Copyright © 2014. Published by Elsevier B.V.

Short-term effect of beta-adrenoreceptor blocking agents on ocular blood flow.

PubMed

Sato, T; Muto, T; Ishibashi, Y; Roy, S

2001-10-01

In this study the acute effect of the topically-delivered non-selective beta-blockers timolol and carteolol, and the selective beta-blocker betaxolol, were evaluated with respect to ocular blood flow, intraocular pressure (IOP) and vessel resistance in rabbits' eyes. In a double masked randomized design, one eye of each subject (n = 9) received two drops of 0.5 % timolol or 2 % cartelol or 0.5 % betaxolol ophthalmic solution and a separate group of nine rabbits received two drops of placebo consisting of physiological saline in both eyes to serve as control. Using hydrogen clearance method, ciliary body blood flow (CiBF), choroidal blood flow (CBF), and retinal blood flow (RBF) were measured. IOP and systemic mean arterial pressure (MAP) of each subject were measured under same condition before and after the administration of respective drugs to calculate the ocular perfusion pressure (OPP) and vessel resistance. In timolol- and carteolol-treated eyes significant reduction was observed in IOP (p < 0.01), CiBF (p < 0.01), CBF (p < 0.01) and RBF (p < 0.01) compared to control eyes. However, in betaxolol-treated eyes a marginal reduction in IOP was observed accompanied by significant increase in CiBF (p < 0.01) and RBF (p < 0.05). The non-selective beta-blocker-treated eyes tended to have increased vessel resistance, whereas, selective beta-blocker-treated eyes tended to have decreased vessel resistance. Our current results comparing non-selective and selective beta-blockers suggest that the selective beta-blocker betaxolol may be more appropriate for maintenance of retinal blood flow in situations with low perfusion. Currently the mechanism for regulation of IOP is unclear; however, the findings from this study indicate that decreased CiBF may contribute to reduction in IOP.

Changes in intraocular pressure values measured with noncontact tonometer (NCT), ocular response analyzer (ORA) and corvis scheimpflug technology tonometer (CST) in the early phase after small incision lenticule extraction (SMILE).

PubMed

Shen, Yang; Su, Xiangjian; Liu, Xiu; Miao, Huamao; Fang, Xuejun; Zhou, Xingtao

2016-11-18

Corneal biomechanical properties are always compromised after corneal refractive surgeries thus leading to underestimated intraocular pressure (IOP) that complicates the management of IOP. We investigated the changes in postoperative baseline of IOP values measured with noncontact tonometer (NCT), ocular response analyzer (ORA) and corvis scheimpflug technology (CST) in the early phase after small incision lenticule extraction (SMILE). Twenty-two eyes (-6.76 ± 1.39D) of 22 moderate and high myopes, (28.36 ± 7.14 years, 12 male and 10 female) were involved in this prospective study. IOP values were measured using a non-contact tomometer (NCT-IOP), an ocular response analyzer (corneal-compensated IOP, IOPcc and Goldmann-correlated IOP, IOPg) and a Corvis scheimpflug technology tonometer (CST-IOP) preoperatively, at 20 min and 24 h, postoperatively. Repeated measures analysis of variance (RM-ANOVA), Pearson's correlation analysis and multiple linear regression models (stepwise) were performed. Cut-off P values were 0.05. Except for IOPcc, NCT-IOP, IOPg, and CST-IOP values significantly decreased after SMILE procedure (All P values <0.05). ΔCCT, as well as ΔMRSE and ΔKm, did not significantly correlated with ΔNCT-IOP, ΔIOPcc, ΔIOPg or ΔCST-IOP, (all P values >0.05). Multiple linear regression models (stepwise) showed that the practical post-operative IOP value was the main predictor of the theoretical post-operative NCT-IOP, IOPcc and IOPg values (all P values <0.001). The postoperative applanation time 1 (AT1) value (B = 8.079, t = 4.866, P < 0.001), preoperative central corneal thickness (CCT) value (B = 0.035, t = 2.732, P = 0.014) and postoperative peak distance (PD) value (B = 0.515, t = 2.176, P = 0.043) were the main predictors of the theoretical post-operative CST-IOP value. IOP values are underestimated when assessed after SMILE by using NCT-IOP, IOPg and CST-IOP. The practical postoperative IOPcc value

Nonarteritic ischemic optic neuropathy secondary to severe ocular hypertension masked by interface fluid in a post-LASIK eye.

PubMed

Pham, Mai T; Peck, Rachel E; Dobbins, Kendall R B

2013-06-01

We report a case of ischemic optic neuropathy arising from elevated intraocular pressure (IOP) masked by interface fluid in a post-laser in situ keratomileusis (LASIK) eye. A 51-year-old man, who had had LASIK 6 years prior to presentation, sustained blunt trauma to the left eye that resulted in a hyphema and ocular hypertension. Elevated IOP resulted in accumulation of fluid in the stromal bed-LASIK flap interface, leading to underestimation of IOP when measured centrally over the flap. After days of unrecognized ocular hypertension, ischemic optic neuropathy developed. To our knowledge, this is the first reported case of ischemic optic neuropathy resulting from underestimated IOP measurements in a post-LASIK patient. It highlights the inaccuracy of IOP measurements in post-LASIK eyes and a vision-threatening potential complication. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Intraocular pressure control with Ahmed glaucoma drainage device in patients with cicatricial ocular surface disease-associated or aniridia-related glaucoma.

PubMed

Almousa, Radwan; Lake, Damian B

2014-08-01

To analyze the control of intraocular pressure (IOP) with an Ahmed glaucoma drainage device (AGDD) in two groups of glaucoma patients--one with cicatricial ocular surface disease (COSD) and one with aniridia. This is a retrospective comparative case series of nine patients (11 eyes) with COSD and six patients (8 eyes) with aniridia who underwent AGDD surgery to control IOP. The main outcome measure in both groups was stability of IOP between 6 and 21 mmHg. Mean IOP decreased significantly in both groups after AGDD surgery (29.6 ± 8.7 vs 14.7 ± 2.5, p = 0.008 in the COSD group; 26.3 ± 8.2 vs 15.3 ± 5.8, p = 0.008 in the aniridia group). Over a mean post-surgery follow-up of 37.1 months in the COSD group, we managed to control IOP in nine eyes; IOP control was successful in 87 % of eyes at 12 months and 58 % of eyes at 26 months. Over a mean post-surgery follow-up of 37.4 months in the aniridia group, we managed to control the IOP in seven eyes; IOP control was successful in 87 % of eyes at 12 months. AGDD surgery had no significant deleterious effect on visual acuity in either group. A severe complication occurred in one eye (1/8) in the aniridia group (lost vision due to retinal detachment) and in one eye (1/11) in the COSD group (tube exposure). AGDD surgery is effective in controlling IOP and has a low complication rate in COSD and aniridia patients; however, some of the complications are severe and prompt management is needed to prevent deleterious results.

Characterization of Intraocular Pressure Increases and Management Strategies Following Treatment With Fluocinolone Acetonide Intravitreal Implants in the FAME Trials.

PubMed

Parrish, Richard K; Campochiaro, Peter A; Pearson, P Andrew; Green, Ken; Traverso, Carlo E

2016-05-01

To compare elevated intraocular pressure (IOP) management and outcomes among patients with diabetic macular edema who received fluocinolone acetonide (FAc) implants versus sham-control treatment and explore the prior ocular steroid exposure impact on IOP outcomes. Best-corrected visual acuity (BCVA) was measured using Early Treatment Diabetic Retinopathy Study charts or electronic VA testers. Goldmann applanation tonometry was used to measure IOP. Elevated IOP was more common in FAc-versus sham control-treated patients. Medication, and less often trabeculoplasty or surgery, was used to lower IOP without affecting VA outcomes. No patient treated with 0.2 µg/day FAc who received prior ocular steroid required IOP-lowering surgery. Elevated IOP may occur following FAc implant receipt; however, in the present study, it was manageable and did not impact vision outcomes. Patients previously treated with ocular steroid did not require IOP-lowering surgery following 0.2 µg/day FAc implant administration. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:426-435.]. Copyright 2016, SLACK Incorporated.

Novel ocular antihypertensive compounds in clinical trials

PubMed Central

Chen, June; Runyan, Stephen A; Robinson, Michael R

2011-01-01

Introduction: Glaucoma is a multifactorial disease characterized by progressive optic nerve injury and visual field defects. Elevated intraocular pressure (IOP) is the most widely recognized risk factor for the onset and progression of open-angle glaucoma, and IOP-lowering medications comprise the primary treatment strategy. IOP elevation in glaucoma is associated with diminished or obstructed aqueous humor outflow. Pharmacotherapy reduces IOP by suppressing aqueous inflow and/or increasing aqueous outflow. Purpose: This review focuses on novel non-FDA approved ocular antihypertensive compounds being investigated for IOP reduction in ocular hypertensive and glaucoma patients in active clinical trials within approximately the past 2 years. Methods: The mode of IOP reduction, pharmacology, efficacy, and safety of these new agents were assessed. Relevant drug efficacy and safety trials were identified from searches of various scientific literature databases and clinical trial registries. Compounds with no specified drug class, insufficient background information, reformulations, and fixed-combinations of marketed drugs were not considered. Results: The investigational agents identified comprise those that act on the same targets of established drug classes approved by the FDA (ie, prostaglandin analogs and β-adrenergic blockers) as well as agents belonging to novel drug classes with unique mechanisms of action. Novel targets and compounds evaluated in clinical trials include an actin polymerization inhibitor (ie, latrunculin), Rho-associated protein kinase inhibitors, adenosine receptor analogs, an angiotensin II type 1 receptor antagonist, cannabinoid receptor agonists, and a serotonin receptor antagonist. Conclusion: The clinical value of novel compounds for the treatment of glaucoma will depend ultimately on demonstrating favorable efficacy and benefit-to-risk ratios relative to currently approved prostaglandin analogs and β-blockers and/or having complementary

Intraocular Pressure and Cardiovascular Alterations Investigated in Artificial Gravity as a Countermeasure to Spaceflight Associated Neuro-ocular Syndrome.

PubMed

Anderson, Allison P; Butterfield, Joseph S; Subramanian, Prem S; Clark, Torin K

2018-05-10

Artificial gravity (AG) has been proposed as a countermeasure to spaceflight associated neuro-ocular syndrome (SANS). The etiology of SANS is unknown, but mimicking gravitational loading through AG may mitigate these negative adaptations. Seventeen subjects (9M, 8F, 18-32 years) were analyzed in four experimental conditions: 1) Standing, 2) Supine, 3) AG with the center of rotation at the eye (AGEC), 4) AG with 2G's at the feet (AG2G). In both AG conditions, subjects were spun to produce 1G at their center of mass. Data included self-administered intraocular pressure (IOP, Tonopen AVIA), heart rate (HR), and mean arterial blood pressure (MAP, Omron Series 10). Data were analyzed with repeated measures ANOVAs, with Tukey-Kramer corrections for multiple pairwise comparisons. IOP was 15.7 {plus minus} 1.4 mmHg (mean{plus minus}95% confidence interval) Standing, 18.8 {plus minus} 1.3 mmHg Supine, 18.5 {plus minus} 1.7 mmHg in AGEC, and 17.5 {plus minus} 1.5 mmHg in AG2G. Postures showed a main effect (F(3,48)=11.0, p<0.0005), with Standing significantly lower than Supine (p=0.0009), AGEC (p=0.002), and AG2G (0.036). Supine, AGEC, and AG2G were not statistically different. HR and MAP were lower in Supine compared to all other postures (p=0.002 to p<0.0005), but there were no differences between Standing, AGEC, and AG2G. IOP in Supine and Standing was consistent with previous studies, but contrary to our hypothesis, remained elevated in both AG conditions. Cardiovascular parameters and hydrostatic gradients determine IOP, which remain unchanged compared to Standing. These results suggest additional influence on IOP from previously unconsidered factors.

Evaluation of monkey intraocular pressure by rebound tonometer

PubMed Central

Yu, Wenhan; Cao, Guiqun; Qiu, Jinghua; Ma, Jia; Li, Ni; Yu, Man; Yan, Naihong; Chen, Lei; Pang, Iok-Hou

2009-01-01

Purpose To evaluate the usefulness of the TonoVet™ rebound tonometer in measuring intraocular pressure (IOP) of monkeys. Methods The accuracy of the TonoVet™ rebound tonometer was determined in cannulated eyes of anesthetized rhesus monkeys where IOP was controlled by adjusting the height of a connected perfusate reservoir. To assess the applicability of the equipment through in vivo studies, the diurnal fluctuation of IOP and effects of IOP-lowering compounds were evaluated in monkeys. Results IOP readings generated by the TonoVet™ tonometer correlated very well with the actual pressure in the cannulated monkey eye. The linear correlation had a slope of 0.922±0.014 (mean±SEM, n=4), a y-intercept of 3.04±0.61, and a correlation coefficient of r2=0.97. Using this method, diurnal IOP fluctuation of the rhesus monkey was demonstrated. The tonometer was also able to detect IOP changes induced by pharmacologically active compounds. A single topical ocular instillation (15 μg) of the rho kinase inhibitor, H1152, produced a 5–6 mmHg reduction (p<0.001) in IOP, lasting at least 4 h. In addition, topical administration of Travatan®, a prostaglandin agonist, induced a small transient IOP increase (1.1 mmHg versus vehicle control; p=0.26) at 2 h after treatment followed by a pressure reduction at 23 h (−2.4 mmHg; p<0.05). Multiple daily dosing with the drug produced a persistent IOP-lowering effect. Three consecutive days of Travatan treatment produced ocular hypotension of −2.0 to −2.2 mmHg (p<0.05) the following day. Conclusions The rebound tonometer was easy to use and accurately measured IOP in the rhesus monkey eye. PMID:19898690

Intra-abdominal pressure during swimming.

PubMed

Moriyama, S; Ogita, F; Huang, Z; Kurobe, K; Nagira, A; Tanaka, T; Takahashi, H; Hirano, Y

2014-02-01

The present study aimed to determine the intra-abdominal pressure during front crawl swimming at different velocities in competitive swimmers and to clarify the relationships between stroke indices and changes in intra-abdominal pressure. The subjects were 7 highly trained competitive collegiate male swimmers. Intra-abdominal pressure was measured during front crawl swimming at 1.0, 1.2 and 1.4 m · s(-1) and during the Valsalva maneuver. Intra-abdominal pressure was taken as the difference between minimum and maximum values, and the mean of 6 stable front crawl stroke cycles was used. Stroke rate and stroke length were also measured as stroke indices. There were significant differences in stroke rate among all velocities (P < 0.05). However, there was no significant difference in stroke length by velocity. Significant within-subject correlations between intra-abdominal pressure and stroke rate or stroke length (P < 0.01) were observed, although there were no significant correlations between intra-abdominal pressure and stroke indices when controlling for swimming velocity. These findings do not appear to support the effectiveness of trunk training performed by competitive swimmers aimed at increasing intra-abdominal pressure. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of sedation with detomidine on intraocular pressure with and without topical anesthesia in clinically normal horses.

PubMed

Holve, Dana L

2012-02-01

To determine the effect of sedation with detomidine on intraocular pressure (IOP) in standing horses and whether topical ocular application of anesthetic alters this effect. Clinical trial. 15 clinically normal horses. Horses were assigned to group 1 (n = 7) or 2 (8). Intraocular pressure measurements were obtained at baseline (before sedation) and 10 minutes after IV administration of detomidine (0.02 mg/kg [0.009 mg/lb]). Group 1 horses had an additional IOP measurement at 20 minutes after sedation. For group 2 horses, topical ocular anesthetic was administered 10 minutes prior to baseline IOP measurements. Mean ± SD baseline IOP for horses without topical anesthesia (group 1 horses; IOP, 24.30 ± 3.09 mm Hg) was significantly lower, compared with that of horses with topical anesthesia (group 2 horses; IOP, 30.40 ± 3.25 mm Hg). Compared with baseline values, IOP at 10 minutes after sedation decreased significantly in all horses (by 3.61 ± 1.48 mm Hg and 5.78 ± 4.32 mm Hg in groups 1 and 2, respectively). In group 1 horses, IOP at 10 (20.69 ± 3.45 mm Hg) and 20 (19.96 ± 2.13 mm Hg) minutes after sedation was significantly decreased, compared with baseline values; however, the difference between IOP at 10 versus 20 minutes was not significant. The difference in IOP between group 1 and 2 horses at 10 minutes after sedation was not significant. IV administration of detomidine caused a decrease in IOP in clinically normal horses and may be a safe sedative when performing ocular procedures.

Evaluation of posterior porcine sclera elasticity in situ as a function of IOP

NASA Astrophysics Data System (ADS)

Nair, Achuth; Wu, Chen; Singh, Manmohan; Liu, Chih Hao; Raghunathan, Raksha; Nguyen, Jennifer; Goh, Megan; Aglyamov, Salavat; Larin, Kirill V.

2018-02-01

The biomechanical properties of the sclera could provide key information regarding the progression and etiology of ocular diseases. For example, an elevated intraocular pressure is one of the most common risk factors for glaucoma and can cause pathological deformations in the tissues of the posterior eye, such as the sclera, potentially damaging these vital tissues. Previous work has evaluated scleral biomechanical response to global displacements with techniques such as inflation testing. However, these methods cannot provide localized biomechanical assessments. In this pilot work, we induce low amplitude (< 10 μm) elastic waves using acoustic radiation force in posterior scleral tissue of fresh porcine eyes (n=2) in situ. The wave propagation induced using an ultrasound transducer was detected across an 8 mm region using a phase-sensitive optical coherence elastography system (PhS-OCE). The elastographic measurements were taken at various artificially controlled intraocular pressures (IOP). The IOP was pre-cycled before being set to 10 mmHg for the first measurement. Subsequent measurements were taken at 20 mmHg and 30 mmHg for each sample. The results show an increase in the stiffness of the sclera as a function of IOP. Furthermore, we observed a variation in the elasticity based on direction, suggesting that the sclera has anisotropic biomechanical properties. Our results show that OCE is an effective method for evaluating the mechanical properties of the sclera, and reveals a new area for our future work.

Circadian rhythm of intraocular pressure in cats.

PubMed

Del Sole, María J; Sande, Pablo H; Bernades, José M; Aba, Marcelo A; Rosenstein, Ruth E

2007-01-01

To evaluate the rhythm of intraocular pressure (IOP) in healthy domestic cats with no evidence of ocular disease and to analyze the influence of photoperiod, age, gender and ocular diseases on diurnal-nocturnal variations of cat IOP. All animals were Domestic Short-haired cats; 30 were without systemic or ocular diseases, classified as follows: 12 male intact adult cats, five intact adult female, five adult spayed female, and eight male cats; the latter were less than 1 year of age. In addition, five adult cats with uveitis and three adult cats with secondary glaucoma were included. IOP was assessed with a Tono-Pen XL at 3-h intervals over a 24-h period in 12 healthy adult male cats kept under a photoperiod of 12-h light/12-h darkness for 2 weeks. Eight animals from the same group were then kept under constant darkness for 48 h, and IOP was measured at 3-h intervals for the following 24 h. In addition, IOP was assessed at 3 p.m. and 9 p.m. in five intact females, five spayed females, and in eight young cats, as well as in five adult cats with uveitis and three glaucomatous cats. Consistent, daily variations in IOP were observed in animals exposed to a light-dark cycle, with maximal values during the night. In cats exposed to constant darkness, maximal values of IOP were observed at subjective night. Differences of IOP values between 3 p.m. and 9 p.m. (diurnal-nocturnal variations) persisted in intact females, spayed females, and young animals, as well as in uveitic and glaucomatous eyes. The present results indicate a daily rhythm of cat IOP, which appears to persist in constant darkness, suggesting some level of endogenous circadian control. In addition, daily variations of cat IOP seem to be independent of gender, age, or ocular diseases (particularly uveitis and glaucoma).

In vivo ocular efficacy profile of mapracorat, a novel selective glucocorticoid receptor agonist, in rabbit models of ocular disease.

PubMed

Shafiee, Afshin; Bucolo, Claudio; Budzynski, Ewa; Ward, Keith W; López, Francisco J

2011-03-14

To compare the efficacy of mapracorat (formerly ZK-245186, and subsequently BOL-303242-X), a novel selective glucocorticoid receptor agonist (SEGRA), with that of dexamethasone (DEX) in rabbit models of ocular disease. The effects of topical BOL-303242-X and DEX on intraocular pressure (IOP) and body weight changes were also evaluated. Dry eye was induced by atropine sulfate administration and was treated with saline, BOL-303242-X (0.1%-1.0%), DEX (0.1%), Restasis 0.05% (Allergan, Inc., Irvine, CA), or Refresh Endura (Allergan, Inc.) three times per day for 7 to 8 days. For paracentesis studies, vehicle, BOL-303242-X (0.1%, 0.5%, and 1.0%), or DEX (0.1%) were repeatedly administered topically 3 hours before paracentesis and continued for 90 minutes afterward. For IOP and body weight measurements, right eyes of rabbits were topically treated with vehicle, BOL-303242-X (1.0% or 0.1%), or DEX (0.1%) four times per day for 6 weeks. In the dry eye model, BOL-303242-X and DEX were fully efficacious, maintaining tear volume and tear breakup time (TBUT) at baseline levels. Although Restasis improved tear volume compared with vehicle, no changes were observed in TBUT. In the paracentesis study, BOL-303242-X and DEX improved ocular inflammation. BOL-303242-X reduced protein and PGE(2) levels. Finally, BOL-303242-X showed no effects on integrated IOP or body weight, whereas DEX significantly increased integrated IOP and prevented the increase of body weight observed in the vehicle-treated animals. BOL-303242-X shows full anti-inflammatory efficacy (similar to DEX) in experimental models of dry eye and postoperative inflammation while demonstrating reduced effects in IOP and body weight. These data indicate that mapracorat, a SEGRA, shows efficacy similar to that of traditional steroids while exhibiting an improved side effect profile in IOP and muscle wasting.

Selected ophthalmic diagnostic tests, bony orbit anatomy, and ocular histology in sambar deer (Rusa unicolor).

PubMed

Oriá, Arianne P; Gomes Junior, Deusdete C; Oliveira, Alberto Vinícius D; Curvelo, Victor P; Estrela-Lima, Alessandra; Pinna, Melissa H; Meneses, Íris D S; Filho, Emanoel F M; Ofri, Ron

2015-01-01

The purpose of this study was to establish reference values for diagnostic ophthalmic tests in sambar deer (Rusa unicolor) as well as to describe the most relevant features of the bony orbital anatomy and ocular histology. Twenty healthy animals, free living in a forest reserve, that were captured for clinical evaluation as part of a health survey were evaluated. Schirmer tear test-1 (STT1), conjunctival microbiota, intraocular pressure (IOP), conjunctival cytology, anatomy of the bony orbit, and ocular histology were studied. Mean ± SD STT1 and IOP values were 18.8 ± 4.7 mm and 11.4 ± 2.8 mmHg, respectively. IOP was significantly higher in adult (4-8 years) animals (P = 0.04). Bacterial growth was present in 100% of the samples, with a prevalence for Staphylococcus sp. and Bacillus sp. The conjunctival cytology revealed predominance of columnar epithelial cells with mild pigmentation. The sambar deer orbit is completely encompassed by bone. The ocular histology was very similar to most mammalians. The findings in this study will be useful in the diagnosis of ocular diseases in Rusa unicolor. © 2014 American College of Veterinary Ophthalmologists.

Longitudinal stability of the diurnal rhythm of intraocular pressure in subjects with healthy eyes, ocular hypertension and pigment dispersion syndrome.

PubMed

Huchzermeyer, Cord; Reulbach, Udo; Horn, Folkert; Lämmer, Robert; Mardin, Christian Y; Jünemann, Anselm G M

2014-10-15

The diurnal fluctuation of intraocular pressure may be relevant in glaucoma. The aim of this study was to find out whether the timing of diurnal fluctuation is stable over the years. Long-term IOP data from the Erlangen Glaucoma Registry, consisting of several annual extended diurnal IOP profiles for each patient, was retrospectively analyzed. Normal subjects, patients with ocular hypertension and with pigment dispersion syndrome were included because these subjects had not been treated with antiglaucomatous medications at the time of data acquisition. A cosine curve was fitted to the IOP data and the stability of individual rhythms over the years was tested using the Rayleigh test. To compare the peak times among groups, means were calculated only from subjects with a significant Rayleigh test. Of the fifty-two eligible subjects, a total of 364 extended diurnal IOP profiles measured in a sitting position had been collected over a period of 114 ± 39 months. The Rayleigh test indicated intraindividual stability of phase timing only in 19 subjects (36%). In subjects with pigment dispersions syndrome, peak IOP occurred on average two hours and seven minutes later during the day compared with subjects without this condition (p = 0.05). Fitting of cosine curves to the clinical IOP profiles was generally feasible, although careful interpretation is warranted due to lack of measurements in supine position and between midnight and 7 am. The interesting observation of a phase lag in eyes with pigment dispersion syndrome warrants confirmation and exploration in future prospective studies. The analysis of the IOP data showed no stable individual rhythm in the long term in a majority of patients.

Poly(N-isopropylacrylamide)-chitosan as thermosensitive in situ gel-forming system for ocular drug delivery.

PubMed

Cao, Yanxia; Zhang, Can; Shen, Wenbin; Cheng, Zhihong; Yu, Liangli Lucy; Ping, Qineng

2007-07-31

A novel copolymer, poly(N-isopropylacrylamide)-chitosan (PNIPAAm-CS), was investigated for its thermosensitive in situ gel-forming properties and potential utilization for ocular drug delivery. The thermal sensitivity and low critical solution temperature (LCST) were determined by the cloud point method. PNIPAAm-CS had a LCST of 32 degrees C, which is close to the surface temperature of the eye. The in vivo ocular pharmacokinetics of timolol maleate in PNIPAAm-CS solution were evaluated and compared to that in conventional eye drop solution by using rabbits according to the microdialysis method. The C(max) of timolol maleate in aqueous fluid for the PNIPAAm-CS solution was 11.2 microg/ml, which is two-fold higher than that of the conventional eye drop, along with greater AUC. Furthermore, the PNIPAAm-CS gel-forming solution of timolol maleate had a stronger capacity to reduce the intra-ocular pressure (IOP) than that of the conventional eye drop of same concentration over a period of 12 h. In addition, the MTT assay showed that there is little cytotoxicity of PNIPAAm-CS at concentration range of 0.5-400 microg/ml. These results suggest that PNIPAAm-CS is a potential thermosensitive in situ gel-forming material for ocular drug delivery, and it may improve the bio-availability, efficacy, and compliance of some eye drugs.

Prospective, non-interventional, multicenter study of the intraocular pressure-lowering effects of prostaglandin analog/prostamide-containing therapies in previously treated patients with open-angle glaucoma or ocular hypertension

PubMed Central

Tamçelik, Nevbahar; Izgi, Belgin; Temel, Ahmet; Yildirim, Nilgun; Okka, Mehmet; Özcan, Altan; Yüksel, Nurşen; Elgin, Ufuk; Altan, Çiğdem; Ozer, Baris

2017-01-01

Objective The objective of this study was to assess the intraocular pressure (IOP)-lowering efficacy, tolerability, safety, and usage patterns of prostaglandin analog/prostamide (PGA/P)-containing topical ocular hypotensives in ocular hypertension (OHT) and primary open-angle glaucoma in the Turkish clinical setting. Methods This non-interventional, multicenter study enrolled previously treated patients who failed to achieve target IOP (or experienced unacceptable adverse events [AEs]) and were prescribed a PGA/P-containing IOP-lowering agent. Treatment was initiated at baseline (V1), and patients returned at weeks 4–6 (V2) and 8–12 (V3). The primary efficacy measure was the change in IOP from baseline at V3 in each eye. The secondary measures were physician’s assessment of IOP-lowering efficacy, patients (%) reaching target IOP determined at V1, hyperemia score, physician and patient assessment of study treatment tolerability at V3, and AE frequency/severity. A subgroup analysis of patients receiving the most common study treatment was conducted. All analyses were performed using the safety population (patients who received one or more doses and had any data available). Results Of 358 enrolled patients, 60.6% had primary open-angle glaucoma, 29.9% had secondary open-angle glaucoma (protocol amendment), and 13.1% had OHT; 13 patients had multiple diagnoses. At V3, the mean IOP change from baseline was ≥−4.2 mmHg (≥21.1%). IOP met or was lower than the target in 81.7% of patients, 95% exhibited none to mild conjunctival hyperemia (most common AE), and tolerability was rated good/very good by >91.1% of patients and physicians. The results were similar in patients who received the most common study treatment, bimatoprost 0.03%/timolol 0.5% (bim/tim; n=310). Conclusion PGA/P-containing medications, including bim/tim, significantly reduced IOP in previously treated patients with open-angle glaucoma or OHT; most reached their target IOP or an IOP even lower

Effects of SofZia-preserved travoprost and benzalkonium chloride-preserved latanoprost on the ocular surface -- a multicentre randomized single-masked study.

PubMed

Aihara, Makoto; Oshima, Hiromi; Araie, Makoto

2013-02-01

To assess the effect of SofZia-preserved travoprost on ocular surface conditions in comparison with benzalkonium chloride (BAK)-preserved latanoprost. A prospective randomized multicentre single-masked comparative study. Patients with open-angle glaucoma or ocular hypertension who had been treated with BAK-preserved latanoprost 0.005% (Xalatan(®) ) monotherapy for at least 3 months. Patients were enrolled at 23 facilities. Patients were randomly divided into the X-X group, continuous use of Xalatan(®) , or the X-T group, switching from Xalatan(®) to SofZia-preserved travoprost 0.004% (TravatanZ(®) ), and followed for 3 months. The superficial punctate keratopathy (SPK), conjunctival epitheliopathy, hyperaemia, tear break-up time (TBUT) and intraocular pressure (IOP) were examined for each patient in a masked manner. Changes in the frequency of keratoconjunctival epitheliopathy were evaluated 3 months after study initiation. Intra- and intergroup comparisons of changes in SPK, conjunctival epitheliopathy, hyperaemia, TBUT and IOP were also carried out. Two hundred twenty patients participated and 215 completed the 3-month study. The frequency of keratoconjunctival epitheliopathy significantly decreased in the X-T group (p = 0.036) and the intergroup difference was also significant (p = 0.001). SPK scores and TBUT were significantly improved in the X-T group (p = 0.034, 0.049), also with significant intergroup differences in the cornea excluding the inferior area and TBUT. There were no significant intergroup differences in changes of the hyperaemia scores and the IOP reduction. Switching to SofZia-preserved travoprost after BAK-preserved latanoprost resulted in a lower incidence of keratoconjunctival epitheliopathy, especially in the cornea, with no clinically relevant changes in hyperaemia and IOP. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

Prevalence and severity of ocular involvement in Graves' disease according to sex and age: A clinical study from Babol, Iran.

PubMed

Gharib, Sara; Moazezi, Zoleika; Bayani, Mohammad Ali

2018-01-01

Thyroid-associated eye disease (TED), previously known as Graves' ophthalmopathy is a cosmetically and functionally debilitating disease that is seen worldwide. The aim of this study was to evaluate the prevalence and clinical severity of ocular manifestations of Graves' disease according to sex, age and duration in northern Iran. Between April 2011 and March 2012, 105 patients with Graves' disease, underwent ophthalmic examination, including ocular motility, exophthalmometry, intraocular pressure (IOP), slit lamp and fundoscopy. Patients received scores according to modified Werner's NO SPECS classification. Ocular involvement was found in 70 patients with established Graves's disease. The mean age was 35.0 years, (SD 13.0, range 15 to 69). The most common ocular findings were exophthalmometric proptosis of more than 20 mm (63.8%), lid lag (55.7%), lid retraction (52.8%) and tearing (38.6%). Almost 70% of patients had bilateral involvement. Elevated IOP was seen in 15 (25.4%) patients, and was significantly related to proptosis (P=0.007). More than half of the patients (n=36, 52.2%) had a modified Werner's NO SPECS score of 3.00. Clinical severity as shown by the increasing number of signs and symptoms per patient was correlated to increasing age (r=0.31, P=0.01) but not to gender (P=0.17). Both functional (ocular motility disorders, increased IOP) and cosmetic (proptosis, periorbital edema) sequels are common ocular presentations in patients with Graves' disease. Proptosis was the most common finding in this study and was associated with elevated IOP. Clinical severity was found to correlate to increasing age.

Regulation of choroidal blood flow during combined changes in intraocular pressure and arterial blood pressure.

PubMed

Polska, Elzbieta; Simader, Christian; Weigert, Günter; Doelemeyer, Arno; Kolodjaschna, Julia; Scharmann, Ole; Schmetterer, Leopold

2007-08-01

To test the hypothesis that human choroidal blood flow (ChBF) may depend, not only on ocular perfusion pressure (OPP), but also on absolute mean arterial pressure (MAP) and intraocular pressure (IOP). There were two study days in an open design. On the first day, OPP was varied by elevating IOP during a squatting-induced increase in MAP (28 subjects). On the second day, only the IOP was increased (17 subjects). IOP was raised in stepwise increments by using the suction cup Subfoveal ChBF (laser Doppler flowmetry), MAP, and IOP were assessed, and OPP was calculated as (2/3)(MAP - IOP). For correlation analysis, data from all subjects were pooled according to IOP and MAP, and correlation analyses were performed. When data from study day 1 were grouped according to IOP, no correlation was observed between ChBF and MAP; but ChBFs were lower, the higher the IOP (P < 0.001). When data were grouped according to MAP, a significant correlation was found between ChBF and IOP (P < 0.001), but correlations were independent of MAP. When data of study day 2 were pooled according to IOP, a correlation between ChBF and OPP was seen only at IOP > 40 mm Hg (P < 0.05). The data confirm previously published observations that the choroid shows some autoregulatory capacity during changes in OPP. In addition, the data indicate that the choroid regulates its blood flow better during exercise-induced changes in MAP than during an experimental increase in IOP.

Intra-Abdominal and Intra-Thoracic Pressures during Lifting and Jumping,

DTIC Science & Technology

1987-03-01

12,15,16,20). The oblique and transverse abdominal muscles, but not the rectus abdominus, have been shown via electromyography (EM0) to be primary...RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Intra- abdominal and intra-thoracic pressures during lifting and...pressure (ITP) and intra- abdominal pressure (lAP) during lifting and jumping, 11 males were monitored as they performed the dead lift (DL), slide row

Two Phase 3 Clinical Trials Comparing the Safety and Efficacy of Netarsudil to Timolol in Patients With Elevated Intraocular Pressure: Rho Kinase Elevated IOP Treatment Trial 1 and 2 (ROCKET-1 and ROCKET-2).

PubMed

Serle, Janet B; Katz, L Jay; McLaurin, Eugene; Heah, Theresa; Ramirez-Davis, Nancy; Usner, Dale W; Novack, Gary D; Kopczynski, Casey C

2018-02-01

To evaluate the efficacy and ocular and systemic safety of netarsudil 0.02% ophthalmic solution, a rho-kinase inhibitor and norepinephrine transporter inhibitor, in patients with open-angle glaucoma and ocular hypertension. Double-masked, randomized noninferiority clinical trials: Rho Kinase Elevated IOP Treatment Trial 1 and 2 (ROCKET-1 and ROCKET-2). After a washout of all pre-study ocular hypotensive medications, eligible patients were randomized to receive netarsudil 0.02% once daily (q.d.), timolol 0.5% twice a day (b.i.d.), and (ROCKET-2 only) netarsudil 0.02% b.i.d. Data through 3 months from both studies are provided in this report. Enrolled into the 2 studies were 1167 patients. Treatment with netarsudil q.d. produced clinically and statistically significant reductions from baseline intraocular pressure (P < .001), and was noninferior to timolol in the per-protocol population with maximum baseline IOP < 25 mm Hg in both studies (ROCKET-2, primary outcome measure and population, ROCKET-1, post hoc outcome measure). Netarsudil b.i.d. was also noninferior to timolol (ROCKET-2). The most frequent adverse event was conjunctival hyperemia, the incidence of which ranged from 50% (126/251, ROCKET-2) to 53% (108/203, ROCKET-1) for netarsudil q.d., 59% (149/253, ROCKET-2) for netarsudil b.i.d., and 8% (17/208, ROCKET-1) to 11% (27/251, ROCKET-2) for timolol (P < .0001 for netarsudil vs timolol). In 2 large, randomized, double-masked trials reported here, once-daily dosing of netarsudil 0.02% was found to be effective and well tolerated for the treatment of patients with ocular hypertension and open-angle glaucoma. The novel pharmacology and aqueous humor dynamic effects of this molecule suggest it may be a useful addition to the armamentarium of ocular hypotensive medications. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Ocular-specific ER stress reduction rescues glaucoma in murine glucocorticoid-induced glaucoma

PubMed Central

Zode, Gulab S.; Sharma, Arti B.; Lin, Xiaolei; Searby, Charles C.; Bugge, Kevin; Kim, Gun Hee; Clark, Abbot F.; Sheffield, Val C.

2014-01-01

Administration of glucocorticoids induces ocular hypertension in some patients. If untreated, these patients can develop a secondary glaucoma that resembles primary open-angle glaucoma (POAG). The underlying pathology of glucocorticoid-induced glaucoma is not fully understood, due in part to lack of an appropriate animal model. Here, we developed a murine model of glucocorticoid-induced glaucoma that exhibits glaucoma features that are observed in patients. Treatment of WT mice with topical ocular 0.1% dexamethasone led to elevation of intraocular pressure (IOP), functional and structural loss of retinal ganglion cells, and axonal degeneration, resembling glucocorticoid-induced glaucoma in human patients. Furthermore, dexamethasone-induced ocular hypertension was associated with chronic ER stress of the trabecular meshwork (TM). Similar to patients, withdrawal of dexamethasone treatment reduced elevated IOP and ER stress in this animal model. Dexamethasone induced the transcriptional factor CHOP, a marker for chronic ER stress, in the anterior segment tissues, and Chop deletion reduced ER stress in these tissues and prevented dexamethasone-induced ocular hypertension. Furthermore, reduction of ER stress in the TM with sodium 4-phenylbutyrate prevented dexamethasone-induced ocular hypertension in WT mice. Our data indicate that ER stress contributes to glucocorticoid-induced ocular hypertension and suggest that reducing ER stress has potential as a therapeutic strategy for treating glucocorticoid-induced glaucoma. PMID:24691439

Influence of infusion volume on the ocular hemodynamic effects of peribulbar anesthesia.

PubMed

Lung, Solveig; Luksch, Alexandra; Weigert, Günther; Georgopoulos, Michael; Menapace, Rupert; Polska, Elzbieta; Garhofer, Gerhard; Findl, Oliver; Schmetterer, Leopold

2006-09-01

To test the hypothesis that ocular blood-flow response to peribulbar anesthesia can be reduced by using a smaller volume of anesthetic mixture. Departments of Ophthalmology and Clinical Pharmacology, Medical University of Vienna, Vienna, Austria. Twenty patients scheduled for bilateral age-related cataract surgery were enrolled in a prospective randomized balanced observer-masked crossover study. Two study days with a 2 mL injection volume or 5 mL injection volume used for peribulbar anesthesia were scheduled. On 1 study day, patients received the 1-dose regimen and on the other study day, when the contralateral eye had surgery, patients received the other injection volume. On both study days, the anesthetic mixture consisted of an equal amount of lidocaine, bupivacaine, and hyaluronidase independently of the injection volume. Intraocular pressure (IOP), blood pressure, and pulse rate were measured noninvasively. Ocular fundus pulsation amplitude (FPA) and peak systolic and end diastolic flow velocities in the central retinal artery were measured with laser interferometry and color Doppler imaging, respectively. The results were recorded as means +/- SD. Peribulbar anesthesia increased IOP and reduced FPA and flow velocities in the central retinal artery. The effects on IOP (5 mL, 35.1% +/- 16.0%; 2 mL, 14.1% +/- 14.1%; P<.001) and ocular hemodynamic parameters (FPA: 5 mL, -17.5% +/- 7.8%/2 mL, -7.3% +/- 7.2%, P<.001; peak systolic velocity: 5 mL, -19.5% +/- 10.7%/2 mL, -10.6% +/- 9.8%, P = .013; end diastolic velocity: 5 mL, -16.7% +/- 6.2%/2 mL, -8.4% +/- 7.3%, P = .005) were more pronounced with the 5 mL injection volume than with the 2 mL injection volume. An injection volume of 2 mL instead of 5 mL reduced the ocular blood-flow response to peribulbar anesthesia. This procedure may be used in patients with ocular vascular disease to reduce the incidence of anesthesia-induced ischemia and loss of vision.

Biomechanical properties of crystalline lens as a function of intraocular pressure assessed noninvasively by optical coherence elastography

NASA Astrophysics Data System (ADS)

Wu, Chen; Aglyamov, Salavat R.; Liu, Chih-Hao; Han, Zhaolong; Singh, Manmohan; Larin, Kirill V.

2017-02-01

Many ocular diseases such as glaucoma and uveitis can lead to the elevation of intraocular pressure (IOP). Previous research implies a link between elevated IOP and lens disease. However, the relationship between IOP elevation and biomechanical properties of the crystalline lens has not been directly studied yet. In this work, we investigated the biomechanical properties of porcine lens as a function of IOP by acoustic radiation force optical coherence elastography.

Effect of dorzolamide and timolol on ocular blood flow in patients with primary open angle glaucoma and ocular hypertension

PubMed Central

Fuchsjäger-Mayrl, G; Wally, B; Rainer, G; Buehl, W; Aggermann, T; Kolodjaschna, J; Weigert, G; Polska, E; Eichler, H-G; Vass, C; Schmetterer, L

2005-01-01

Background: There is evidence that perfusion abnormalities of the optic nerve head are involved in the pathogenesis of glaucoma. There is therefore considerable interest in the effects of topical antiglaucoma drugs on ocular blood flow. A study was undertaken to compare the ocular haemodynamic effects of dorzolamide and timolol in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). Methods: One hundred and forty patients with POAG or OHT were included in a controlled, randomised, double blind study in two parallel groups; 70 were randomised to receive timolol and 70 to receive dorzolamide for a period of 6 months. Subjects whose intraocular pressure (IOP) did not respond to either of the two drugs were switched to the alternative treatment after 2 weeks. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the optic nerve head. Pulsatile choroidal blood flow was assessed using laser interferometric measurement of fundus pulsation amplitude. Results: Five patients did not respond to timolol and were changed to the dorzolamide group, and 18 patients changed from dorzolamide treatment to timolol. The effects of both drugs on IOP and ocular perfusion pressure were comparable. Dorzolamide, but not timolol, increased blood flow in the temporal neuroretinal rim (8.5 (1.6)%, p<0.001 versus timolol) and the cup of the optic nerve head (13.5 (2.5)%, p<0.001 versus timolol), and fundus pulsation amplitude (8.9 (1.3)%, p<0.001 versus timolol). Conclusions: This study indicates augmented blood flow in the optic nerve head and choroid after 6 months of treatment with dorzolamide, but not with timolol. It remains to be established whether this effect can help to reduce visual field loss in patients with glaucoma. PMID:16170119

Polyquaternium-1-Preserved Travoprost 0.003% or Benzalkonium Chloride-Preserved Travoprost 0.004% for Glaucoma and Ocular Hypertension.

PubMed

Peace, James H; Ahlberg, Peter; Wagner, Mathias; Lim, John M; Wirta, David; Branch, James D

2015-08-01

To demonstrate equivalence of polyquaternium-1-preserved travoprost 0.003% with benzalkonium chloride-preserved travoprost 0.004% in patients with open-angle glaucoma or ocular hypertension. Double-masked, randomized, 2-treatment, equivalence clinical trial. setting: Multicenter clinical trial conducted in 60 centers in the United States and Europe. Adult patients with open-angle glaucoma or ocular hypertension. One eye per patient was analyzed. Patients were randomized 1:1 to receive polyquaternium-1-preserved travoprost 0.003% (n = 442) or benzalkonium chloride-preserved travoprost 0.004% (n = 422) once daily for 3 months. Mean intraocular pressure (IOP) was assessed at 8 AM, 10 AM, and 4 PM at week 2, week 6, and month 3. Supportive outcomes were mean and percent IOP change, percentage of patients achieving IOP <18 mm Hg or ≥30% IOP reduction, and adverse events. Mean IOP was similar between groups at all study visits (travoprost 0.003% range, 17.5-18.9 mm Hg; travoprost 0.004% range, 17.4-19.0 mm Hg). Mean change (least squares mean differences, -0.1 to 0.3 mm Hg; 95% confidence interval, -0.5 to 0.7 mm Hg) and percentage change (travoprost 0.003%, 28.4%-30.7%; travoprost 0.004%, 28.5%-31.0%) from baseline were comparable. The percentages of patients with IOP <18 mm Hg and ≥30% reduction of IOP were also similar. Hyperemia was the most frequent treatment-related adverse event with both formulations (travoprost 0.003%, 11.8%; travoprost 0.004%, 14.5%). In patients with open-angle glaucoma or ocular hypertension, polyquaternium-1-preserved travoprost 0.003% solution provided equivalent IOP-lowering efficacy to that of benzalkonium chloride-preserved travoprost 0.004%. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of inhibition of nitric oxide synthase on basal anterior segment ocular blood flows and on potential autoregulatory mechanisms.

PubMed

Koss, M C

2001-08-01

Experiments were undertaken to determine the role played by nitric oxide (NO) in basal ocular blood flow in the anterior aspect of the eye. Subsequent studies focused on existence of autoregulatory mechanisms and on the potential involvement of NO. Cats were anesthetized with pentobarbital (36 mg/kg, i.p.). A femoral artery and vein were cannulated for measuring blood pressure and for drug administration, respectively. Anterior segment blood flow was measured in a continuous fashion from the long posterior ciliary artery (LPCA) using ultrasonic flowmetry and from the anterior choroid using laser-Doppler flowmetry. A needle was placed into the anterior chamber, and autoregulatory mechanisms were studied by decreasing ocular perfusion pressure via stepwise elevations of IOP. Non-selective inhibition of NO synthase with L-NAME (20 mg/kg, i.v.) significantly decreased basal blood flow from both sites. L-NAME (5 mg/kg, i.v.) was without effect as was D-NAME (25 mg/kg, i.v.). Increasing IOP produced a linear decrease on LPCA blood flow indicating absence of autoregulation. In contrast, stepwise elevation of IOP produced a delayed, non-linear response in the anterior choroid suggestive of a strong autoregulatory response. Neither response to elevated ocular perfusion pressure was further altered by inhibition of NO synthase with L-NAME (20 mg/kg, i.v.). The results confirm previous reports that nitric oxide plays a pivotal role in maintenance of basal ocular blood flow. Autoregulation was not seen in the LPCA. In contrast, there was a clear autoregulatory response in the anterior choroid, although neither response was altered by inhibition of NO synthase.

System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

PubMed Central

Stockslager, Max A.; Samuels, Brian C.; Allingham, R. Rand; Klesmith, Zoe A.; Schwaner, Stephen A.; Forest, Craig R.; Ethier, C. Ross

2016-01-01

Pathologic changes in intracranial pressure (ICP) are commonly observed in a variety of medical conditions, including traumatic brain injury, stroke, brain tumors, and glaucoma. However, current ICP measurement techniques are invasive, requiring a lumbar puncture or surgical insertion of a cannula into the cerebrospinal fluid (CSF)-filled ventricles of the brain. A potential alternative approach to ICP measurement leverages the unique anatomy of the central retinal vein, which is exposed to both intraocular pressure (IOP) and ICP as it travels inside the eye and through the optic nerve; manipulating IOP while observing changes in the natural pulsations of the central retinal vein could potentially provide an accurate, indirect measure of ICP. As a step toward implementing this technique, we describe the design, fabrication, and characterization of a system that is capable of manipulating IOP in vivo with <0.1 mmHg resolution and settling times less than 2 seconds. In vitro tests were carried out to characterize system performance. Then, as a proof of concept, we used the system to manipulate IOP in tree shrews (Tupaia belangeri) while video of the retinal vessels was recorded and the caliber of a selected vein was quantified. Modulating IOP using our system elicited a rapid change in the appearance of the retinal vein of interest: IOP was lowered from 10 to 3 mmHg, and retinal vein caliber sharply increased as IOP decreased from 7 to 5 mmHg. Another important feature of this technology is its capability to measure ocular compliance and outflow facility in vivo, as demonstrated in tree shrews. Collectively, these proof-of-concept demonstrations support the utility of this system to manipulate IOP for a variety of useful applications in ocular biomechanics, and provide a framework for further study of the mechanisms of retinal venous pulsation. PMID:26771837

Changes in biomechanical properties of the cornea and intraocular pressure after myopic laser in situ keratomileusis using a femtosecond laser for flap creation determined using ocular response analyzer and Goldmann applanation tonometry.

PubMed

Shin, Jonghoon; Kim, Tae Won; Park, Soo Jeong; Yoon, Min; Lee, Ji Woong

2015-03-01

To compare intraocular pressure (IOP) measurements before and after laser in situ keratomileusis (LASIK) using a femtosecond laser for flap creation, and to identify factors that may influence the preoperative and postoperative IOP, and the change in IOP after LASIK. Forty eyes from 20 patients who underwent treatment for myopia using a femtosecond laser for flap creation were enrolled in this study. The IOP and corneal biomechanical markers were prospectively measured preoperatively and 1 month after LASIK with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA). Manifest refraction spherical equivalent, central corneal thickness, ablation depth, and mean corneal curvature (K reading) were also recorded. After LASIK, there was a significant reduction in the IOP measurement with respect to the corneal-compensated intraocular pressure (IOPcc) (Δ=-0.67±2.07 mm Hg), Goldmann-correlated pressure (IOPg) (Δ=-3.92±2.19 mm Hg), and GAT (Δ=-2.6±2.51). Multiple regression analysis revealed that the corneal hysteresis (CH) and corneal resistance factor (CRF) are statistically significant predictors of IOPcc, IOPg, and GAT (P<0.000). In this analysis, the preoperative manifest refraction spherical equivalent, CH, and CRF were significant predictors of ΔIOPcc (adjusted R²=0.401) and ΔIOPg (adjusted R²=0.386). The preoperative SE and central corneal thickness significantly predicted ΔGAT (adjusted R²=0.464). ORA provides a more complete measurement of IOP after LASIK with a femtosecond laser than GAT because ORA provides greater knowledge of the corneal biomechanics in terms of CH and CRF.

An observational study of bimatoprost 0.01% in treatment-naïve patients with primary open angle glaucoma or ocular hypertension: the CLEAR trial

PubMed Central

Nixon, Donald R; Simonyi, Susan; Bhogal, Meetu; Sigouin, Christopher S; Crichton, Andrew C; Discepola, Marino; Hutnik, Cindy ML; Yan, David B

2012-01-01

Background This study was designed to evaluate the occurrence and severity of ocular hyperemia in subjects with elevated intraocular pressure (IOP) due to primary open angle glaucoma (POAG) or ocular hypertension (OHT) following treatment with bimatoprost 0.01% in a real-world clinical setting. Methods This was an open-label, observational study conducted at 67 centers in Canada. Subjects with elevated IOP due to POAG or OHT instilled bimatoprost 0.01% topically as monotherapy once daily. Ocular hyperemia was graded by the investigator at baseline and weeks 6 and 12 using a photographic five-point grading scale. Change in IOP from baseline was also evaluated at these time points. This analysis includes only the subgroup of 522 subjects who were naïve to IOP-lowering medication prior to the study. Results After 12 weeks of treatment with bimatoprost 0.01%, hyperemia was graded as none-to-mild (grades 0, +0.5, or +1) for 93.3% of subjects and as moderate-to-severe (grades +2 or +3) for 6.7%. At weeks 6 and 12, most subjects (93.2% and 93.5%) had no change in hyperemia grade from baseline. IOP was reduced by 7.4 mmHg (29.8%) at week 6 and 7.7 mmHg (30.9%) at week 12 from baseline. Conclusion This real-world, observational study found that bimatoprost 0.01% instilled once daily reduced IOP by a mean of 30% from baseline without moderate or severe ocular hyperemia in 93% of treatment-naïve subjects with POAG or OHT. PMID:23269858

An evaluation of the effects of eyeball structure on ocular pulse amplitude in healthy subjects.

PubMed

Ishii, Kotaro; Mori, Mikiro; Oshika, Tetsuro

2012-12-01

To evaluate the effects of eyeball structure on ocular pulse amplitude (OPA) measured using dynamic contour tonometer (DCT). In 86 eyes of 43 healthy subjects, we measured OPA and intraocular pressure (IOP) with DCT (DCT-IOP), IOP with Goldmann applanation tonometry (GAT-IOP), central corneal thickness (CCT), corneal thickness 2 mm (2 mmCT) and 4 mm (4 mmCT) apart from the center, corneal volume within a 3.5-mm radius from the corneal center, corneal curvature, anterior chamber depth, anterior chamber volume, and axial length (AL). OPA had a significant positive correlation with GAT-IOP (Pearson's r = 0.412, p < 0.001), DCT-IOP (r = 0.350, p < 0.001), and 4 mmCT (r = 0.244, p = 0.0231), and had a significant negative correlation with AL (r = -0.268, p = 0.0122). In a multiple linear regression analysis, AL and GAT-IOP were significantly associated with OPA. OPA measured with DCT is significantly influenced by several factors, such as IOP, peripheral corneal thickness (4 mmCT), and AL.

Intra-ocular pressure normalization technique and equipment

NASA Technical Reports Server (NTRS)

Mcgannon, W. J. (Inventor)

1980-01-01

A method and apparatus for safely reducing abnormally high intraocular pressure in an eye during a predetermined time interval is presented. This allows maintenance of normal intraocular pressure during glaucoma surgery. According to the invention, a pressure regulator of the spring biased diaphragm type is provided with additional bias by a column of liquid. The height of the column of liquid is selected such that the pressure at a hypodermic needle connected to the output of the pressure regulator is equal to the measured pressure of the eye. The hypodermic needle can then be safely inserted into the anterior chamber of the eye. Liquid is then bled out of the column to reduce the bias on the diaphragm of the pressure regulator and, consequently, the output pressure of the regulator. This lowering pressure of the regulator also occurs in the eye by means of a small second bleed path provided between the pressure regulator and the hypodermic needle. Alternately, a second hypodermic needle may be inserted into the eye to provide a controlled leak off path for excessive pressure and clouded fluid from the anterior chamber.

Corneal elastic anisotropy and hysteresis as a function of IOP assessed by optical coherence elastography

NASA Astrophysics Data System (ADS)

Li, Jiasong; Singh, Manmohan; Han, Zhaolong; Wu, Chen; Raghunathan, Raksha; Liu, Chih-Hao; Nair, Achuth; Noorani, Shezaan; Aglyamov, Salavat R.; Twa, Michael D.; Larin, Kirill V.

2016-03-01

The mechanical anisotropic properties of the cornea can be an important indicator for determining the onset and severity of different diseases and can be used to assess the efficacy of various therapeutic interventions, such as cross-linking and LASIK surgery. In this work, we introduce a noncontact method of assessing corneal mechanical anisotropy as a function of intraocular pressure (IOP) using optical coherence elastography (OCE). A focused air-pulse induced low amplitude (<10 μm) elastic waves in fresh porcine corneas in the whole eye-globe configuration in situ. A phase-stabilized swept source optical coherence elastography (PhS-SSOCE) system imaged the elastic wave propagation at stepped radial angles, and the OCE measurements were repeated as the IOP was cycled. The elastic wave velocity was then quantified to determine the mechanical anisotropy and hysteresis of the cornea. The results show that the elastic anisotropy at the corneal of the apex of the cornea becomes more pronounced at higher IOPs, and that there are distinct radial angles of higher and lower stiffness. Due to the noncontact nature and small amplitude of the elastic wave, this method may be useful for characterizing the elastic anisotropy of ocular and other tissues in vivo completely noninvasively.

Intra-ocular pressure normalization technique and equipment

NASA Technical Reports Server (NTRS)

Baehr, E. F. (Inventor)

1979-01-01

A method and apparatus is described for safely reducing abnormally high intraocular pressure in an eye during a predetermined time interval. This allows maintenance of normal intraocular pressure during glaucoma surgery. A pressure regulator of the spring-biassed diaphragm type is provided with additional bias by a column of liquid. The hypodermic needle can be safely inserted into the anterior chamber of the eye. Liquid is then bled out of the column to reduce the bias on the diaphragm of the pressure regulator and, consequently, the output pressure of the regulator. This lowering pressure of the regulator also occurs in the eye by means of a small second bleed path provided between the pressure regulator and the hypodermic needle.

Translamina Cribrosa Pressure Difference as Potential Element in the Pathogenesis of Glaucomatous Optic Neuropathy.

PubMed

Jonas, Jost B; Wang, Ningli; Yang, Diya

2016-01-01

The main proven risk factor for glaucomatous optic neuropathy (GON) is an intraocular pressure (IOP) higher than the pressure sensibility of the optic nerve head allows. Fulfilling Koch postulates, numerous studies have shown that the presence of high IOP leads to GON, that lowering IOP stops the progression of GON, and that a re-increase in IOP again causes the progression of GON. There are, however, many patients with glaucoma who have statistically normal or low IOP, and despite low IOP values, they develop progressing GON. These observations led to findings that IOP is only 1 of 2 determinants of the translamina cribrosa pressure difference (TLCPD), which is the main pressure-related parameter for the physiology and pathophysiology of the optic nerve head. The second parameter influencing TLCPD is orbital cerebrospinal fluid pressure (CSFP) as the counter pressure against IOP across the lamina cribrosa. Recent experimental and clinical studies have suggested that a low CSFP could be associated with GON in normal-pressure glaucoma. These investigations included studies with an experimental long-term reduction in CSFP in monkeys, population-based studies, and clinical retrospective and prospective investigations on patients with normal-pressure glaucoma. Besides TLCPD, other ocular parameters influenced by CSFP may be choroidal thickness, retinal vein pressure and diameter, occurrence of retinal vein occlusions, and occurrence and severity of diabetic retinopathy.

Assessment of intraocular pressure measured by Reichert Ocular Response Analyzer, Goldmann Applanation Tonometry, and Dynamic Contour Tonometry in healthy individuals

PubMed Central

Ouyang, Ping-Bo; Li, Cong-Yi; Zhu, Xiao-Hua; Duan, Xuan-Chu

2012-01-01

AIM To investigate the accuracy of intraocular pressure (IOP) as measured by a Reichert Ocular Response Analyzer (ORA), as well as the relationship between central corneal thickness (CCT) and IOP as measured by ORA, Goldmann applanation tonometry (GAT), and dynamic contour tonometry (DCT). METHODS A total of 158 healthy individuals (296 eyes) were chosen randomly for measurement of IOP. After CCT was measured using A-ultrasound (A-US), IOP was measured by ORA, GAT, and DCT devices in a randomized order. The IOP values acquired using each of the three tonometries were compared, and the relationship between CCT and IOP values were analyzed separately. Two IOP values, Goldmann-correlated IOP value (IOPg) and corneal-compensated intraocular pressure (IOPcc), were got using ORA. Three groups were defined according to CCT: 1) thin cornea (CCT<520µm); 2) normal-thickness cornea (CCT: 520–580µm); and 3) thick cornea (CCT>580µm) groups. RESULTS In normal subjects, IOP measurements were 14.95±2.99mmHg with ORA (IOPg), 15.21±2.77mmHg with ORA (IOPcc), 15.22±2.77mmHg with GAT, and 15.49±2.56mmHg with DCT. Mean differences were 0.01±2.29mmHg between IOPcc and GAT (P>0.05) and 0.28±2.20mmHg between IOPcc and DCT (P>0.05). There was a greater correlation between IOPcc and DCT (r=0.946, P=0.000) than that between IOPcc and GAT (r=0.845, P=0.000). DCT had a significant correlation with GAT (r=0.854, P=0.000). GAT was moderately correlated with CCT (r=0.296, P<0.001), while IOPcc showed a weak but significant correlation with CCT (r=−0.155, P=0.007). There was a strong negative correlation between CCT and the difference between IOPcc and GAT(r=-0.803, P=0.000), with every 10µm increase in CCT resulting in an increase in this difference of 0.35mmHg. The thick cornea group (CCT>580µm) showed the least significant correlation between IOPcc and GAT (r=0.859, P=0.000); while the thin cornea group (CCT<520µm) had the most significant correlation between IOPcc and GAT (r=0

21 CFR 886.4610 - Ocular pressure applicator.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4610 Ocular pressure applicator. (a... bulb, a dial indicator, a band, and bellows, intended to apply pressure on the eye in preparation for...

Manipulation of intraocular pressure for studying the effects on accommodation.

PubMed

He, Lin; Wendt, Mark; Glasser, Adrian

2012-09-01

A reliable experimental system in which IOP can be manipulated or a rapid IOP change can be induced while simultaneously and continuously measuring IOP and the ocular accommodative changes would be useful for understanding the physiological effect of intraocular pressure (IOP) on the accommodative mechanism. In this study, an IOP perfusion and recording system was developed and tested using 13 enucleated pig eyes. The vitreous chamber of the pig eyes was cannulated with a needle connected to two fluid reservoirs at different heights. One reservoir was set to achieve one of three baseline pressures of 5.5 mmHg, 13.0 mmHg and 20.5 mmHg. The other reservoir was moved to achieve pressures of 1.5 mmHg, 3.0 mmHg, 4.5 mmHg and 6.0 mmHg higher than the baseline pressure. The height differential between the reservoirs determined the amplitude of IOP changes. Rapid IOP changes were induced by switching the reservoirs with a solenoid pinch-valve. Two needles, one each attached to a pressure transducer were inserted into the anterior chamber and vitreous chamber respectively. Custom developed software was used to measure the anterior chamber pressure and vitreous chamber pressure at 80 Hz. A high-resolution continuous A-scan ultrasound biometer (CUB) was used to dynamically measure changes in ocular biometry including anterior chamber depth (ACD), lens thickness (LT) and vitreous chamber depth (VCD) while the vitreous chamber pressure was manipulated. The changes in ACD, LT and VCD were analyzed as a function of the pressure change. Perfusion-induced axial biometric changes were quantified by the slopes of linear regression relationships. Both anterior chamber pressure and vitreous chamber pressure changed relatively systematically with the induced vitreous chamber pressure changes (anterior chamber: y = 0.863x + 0.030, r(2) = 0.983; vitreous chamber: y = 0.883x + 0.009, r(2) = 0.981). At perfusion pressures of 5.5, 13.0 and 20.5 mmHg, the slopes for ACD

Ocular manifestations of Type 1 diabetes mellitus in pediatric population.

PubMed

Akil, Handan; Buluş, Ayse Derya; Andiran, Nesibe; Alp, Mehmet Numan

2016-09-01

To evaluate the necessity of ocular screening in Type 1 diabetes mellitus (DM). This study aims to investigate the diabetes-related ocular changes according to the glycosylated hemoglobin (HbA1c) level and duration of diabetes in children and compare the results with nondiabetic healthy children. Observational cross-sectional study designed by ophthalmology and pediatric endocrinology clinics. Forty-two children with Type 1 DM, 42 healthy gender- and age-matched children as controls were enrolled. All patients underwent ophthalmic and physical examination, with a review of medical history and current medication. HbA1c level, best corrected visual acuity, intraocular pressure (IOP), central corneal thickness (CCT), tear break-up time (BUT), Schirmer test, dilated fundus examination findings, central retinal thickness (CRT), and total macular volume (TMV) measurements were noted. Descriptive statistics, Student's t-test, Mann-Whitney U-test, Chi-square test for comparison of the group parameters and correlation analyses (Spearman analysis) were performed with SPSS statistical software 17.0 (SPSS Inc., Chicago, IL, USA). Type 1 DM group exhibited significantly reduced Schirmer test, increased IOP and decreased retinal thickness relative to the age-matched control group (P < 0.05) but no statistically significant difference was found for the BUT (P = 0.182) and for the CCT (P = 0.495). The correlations between the age, duration, HbA1c and IOP, BUT, Schirmer test, TMV, CRT measurements did not reach statistical significance. More frequent screening may be needed for complications, including neuropathy-related dry eye syndrome, IOP changes, and diabetic retinopathy in children with Type 1 DM.

Effects of topical nipradilol, a β blocking agent with α blocking and nitroglycerin-like activities, on intraocular pressure and aqueous dynamics in humans

PubMed Central

Kanno, M.; Araie, M.; Koibuchi, H.; Masuda, K.

2000-01-01

AIMS—To study the effects of topical nipradilol, a non-selective β blocker with α blocking and nitroglycerin-like activities, on intraocular pressure (IOP) and aqueous humour dynamics in normal humans and in patients with ocular hypertension.
METHODS—Nipradilol (0.06%, 0.125%, 0.25%, 0.5%) was applied to normal volunteers (n = 12) to test for IOP lowering effects. In a second group of normal volunteers (n = 11), nipradilol (0.125% and 0.25%) and timolol (0.5%) were compared for IOP lowering effects. After a single administration of 0.25% nipradilol, IOP, flare intensity in the anterior chamber, aqueous flow, uveoscleral outflow, tonographic outflow facility, and episcleral venous pressure were either directly measured or mathematically calculated. Topical nipradilol (0.25%) was administered to 24 patients with ocular hypertension twice daily for 8 weeks.
RESULTS—Administration of 0.25% nipradilol decreased IOP with a maximum reduction of 4.2 mm Hg lasting 12 hours. A single instillation of both 0.25% nipradilol and 0.5% timolol reduced the IOP in normotensive human subjects to the same degree. A single instillation of 0.25% nipradilol decreased the aqueous flow rate in the treated eye by 20%. Nipradilol produced no significant effect in tonographic outflow facility or episcleral venous pressure, but uveoscleral outflow was increased. In patients with ocular hypertension, twice daily instillation of 0.25% nipradilol decreased IOP without tachyphylaxis for the 8 week test period.
CONCLUSION—Topical nipradilol (0.25%) reduced IOP by decreasing the aqueous flow rate and probably also by increasing uveoscleral outflow. Nipradilol should be further investigated as a new antiglaucoma drug.

 PMID:10684841

EP3/FP dual receptor agonist ONO-9054 administered morning or evening to patients with open-angle glaucoma or ocular hypertension: results of a randomised crossover study

PubMed Central

Berlin, Michael S; Rowe-Rendleman, Cheryl; Ahmed, Ike; Ross, Douglas T; Fujii, Akifumi; Ouchi, Takafumi; Quach, Christine; Wood, Andrew; Ward, Caroline L

2016-01-01

Background/aims The novel prostaglandin E (EP) 3 and prostaglandin F (FP) receptor agonist ONO-9054 is effective in lowering intraocular pressure (IOP) in patients with ocular hypertension and open-angle glaucoma when administered once daily. This study compares the effects of morning (AM) versus evening (PM) dosing of ONO-9054 on tolerability and IOP lowering. Methods This was a single-centre, randomised, double-masked, two-sequence, placebo-controlled crossover study in 12 subjects with bilateral primary open-angle glaucoma or ocular hypertension. Two 14-day crossover regimens were separated by a 2-week washout: ONO-9054 (1 drop to each eye) in the morning (07:00) and vehicle in the evening (19:00) and vice versa. IOP was measured multiple times during select days. Ocular examinations also evaluated safety and tolerability. Results Mild ocular hyperaemia, reported by six subjects with PM dosing, was the most frequent adverse event. Mild to moderate dryness was also slightly more frequent after PM dosing. Maximum IOP reduction from baseline occurred on day 2 with decreases from baseline of −7.4 mm Hg (−30.8%) for AM dosing and −9.1 mm Hg, (−38.0%) for PM dosing; after 14 days, mean reduction in IOP was −6.8 mm Hg (−28.6%) for AM dosing and −7.5 mm Hg (−31.0%) for PM dosing. Conclusions PM dosing of ONO-0954 was associated with a slightly increased frequency of mild hyperaemia and mild to moderate dryness. Both dosing schedules provided sustained reduction in IOP. Trial registration number NCT01670266. PMID:26453641

Comparison of surgical time and IOP spikes with two ophthalmic viscosurgical devices following Visian STAAR (ICL, V4c model) insertion in the immediate postoperative period.

PubMed

Ganesh, Sri; Brar, Sheetal

2016-01-01

To compare the effect of two ocular viscosurgical devices (OVDs) on intraocular pressure (IOP) and surgical time in immediate postoperative period after bilateral implantable collamer lens (using the V4c model) implantation. A total of 20 eligible patients were randomized to receive 2% hydroxypropylmethylcellulose (HPMC) in one eye and 1% hyaluronic acid in fellow eye. Time taken for complete removal of OVD and total surgical time were recorded. At the end of surgery, IOP was adjusted between 15 and 20 mmHg in both the eyes. Mean time for complete OVD evacuation and total surgical time were significantly higher in the HPMC group (P=0.00). Four eyes in the HPMC group had IOP spike, requiring treatment. IOP values with noncontact tonometry at 1, 2, 4, 24, and 48 hours were not statistically significant (P>0.05) for both the groups. The study concluded that 1% hyaluronic acid significantly reduces total surgical time, and incidence of acute spikes may be lower compared to 2% HPMC when used for implantable collamer lens (V4c model).

Comparison of surgical time and IOP spikes with two ophthalmic viscosurgical devices following Visian STAAR (ICL, V4c model) insertion in the immediate postoperative period

PubMed Central

Ganesh, Sri; Brar, Sheetal

2016-01-01

Purpose To compare the effect of two ocular viscosurgical devices (OVDs) on intraocular pressure (IOP) and surgical time in immediate postoperative period after bilateral implantable collamer lens (using the V4c model) implantation. Methods A total of 20 eligible patients were randomized to receive 2% hydroxypropylmethylcellulose (HPMC) in one eye and 1% hyaluronic acid in fellow eye. Time taken for complete removal of OVD and total surgical time were recorded. At the end of surgery, IOP was adjusted between 15 and 20 mmHg in both the eyes. Results Mean time for complete OVD evacuation and total surgical time were significantly higher in the HPMC group (P=0.00). Four eyes in the HPMC group had IOP spike, requiring treatment. IOP values with noncontact tonometry at 1, 2, 4, 24, and 48 hours were not statistically significant (P>0.05) for both the groups. Conclusion The study concluded that 1% hyaluronic acid significantly reduces total surgical time, and incidence of acute spikes may be lower compared to 2% HPMC when used for implantable collamer lens (V4c model). PMID:26869754

Correlations between different tonometries and ocular biometric parameters in patients with primary congenital glaucoma.

PubMed

Mendes, Marcio Henrique; Betinjane, Alberto Jorge; Quiroga, Veronica Andrea

2013-01-01

To identify the correlation between the difference of intraocular pressure measurements (IOP) obtained using the Goldmann applanation tonometer (GAT) and three others tonometers (Handheld applanation tonometer - HAT, Dynamic contour tonometer - DCT and Tono-Pen®) with biometric characteristics (corneal diameter, pachymetry, keratometry and axial length) in patients with congenital glaucoma. A cross-sectional study was performed on 46 eyes from 46 patients with congenital glaucoma. IOP measurements were obtained in all patients using GAT, HAT, DCT and Tono-Pen®. Keratometry, pachymetry, biometry and corneal diameter measurements were performed after the IOP measurement. The order of the tonometries was randomized. The correlations between the differences of IOP values of GAT and the other tonometers (Delta-IOP), and the different biometric parameters were studied. Tono-Pen® Delta IOP revealed moderate positive correlation to keratometry (r=0.41, p=0.004). The other Delta-IOPs showed no correlation with any of the biometric characteristics evaluated. IOP differences between GAT (gold standard) and GAT, HAT, DCT or Tono-Pen tonometers seem not to correlate with majority of ocular biometric characteristics. The only exception was the keratometry, which correlated in a positive and moderate way with Tono-Pen® Delta-IOP. This result suggests that the differences of IOP values of Tono-Pen® and GAT increase with the steepness of the cornea.

An observational study of bimatoprost 0.01% in patients on prior intraocular pressure-lowering therapy: the Canadian Lumigan® RC Early Analysis Review (CLEAR) trial

PubMed Central

Crichton, Andrew C; Nixon, Donald R; Simonyi, Susan; Bhogal, Meetu; Sigouin, Christopher S; Discepola, Marino J; Hutnik, Cindy ML; Baptiste, Darryl C; Yan, David B

2014-01-01

Purpose To evaluate the ocular hyperemia and intraocular pressure (IOP)-lowering efficacy of bimatoprost 0.01% in subjects with elevated IOP due to primary open-angle glaucoma (POAG) or ocular hypertension (OHT) in a real-world clinical setting. Subjects and methods This open-label, 12-week, observational study was conducted at 67 centers in Canada. Subjects with elevated IOP due to POAG or OHT instilled bimatoprost 0.01% as monotherapy once daily. Ocular hyperemia was graded by the investigator at baseline, week 6, and week 12 using a standardized photographic 5-point grading scale. Change in IOP from baseline was also evaluated at these time points. This analysis includes the subgroup of 268 subjects who had been previously treated with latanoprost 0.005%, bimatoprost 0.03%, travoprost 0.004%, and travoprost 0.004% with SofZia™ or nonselective beta-adrenergic receptor blockers prior to the study. Results After 12 weeks of treatment with 0.01% bimatoprost, ocular hyperemia was graded as none-to-mild hyperemia (grades 0, +0.5, or +1) for 94.1% of subjects and as moderate-to-severe hyperemia (grades +2 or +3) for 5.9%. No statistically significant shifts in ocular hyperemia ratings were observed at week 12 for any of the prior IOP-lowering therapies except bimatoprost 0.03%, in which 20.8% of subjects experienced an improvement. The mean percentage change from baseline IOP at week 12 following the switch to bimatoprost 0.01% monotherapy ranged from −2.3%±17.3% to −26.3%±12.4%. Furthermore, the decreased mean percentage change from baseline IOP was statistically significant across all prior IOP-lowering medications, except for bimatoprost 0.03% at the 6- and 12-week visits and travoprost 0.004% at the 6-week visit. Conclusion This observational study demonstrates that bimatoprost 0.01% was well tolerated among POAG and OHT subjects who switched from prior IOP-lowering medication. Furthermore, a switch in ocular hypertensive treatment to bimatoprost 0.01% was

Efficacy and safety of travoprost alone or in combination with other agents for glaucoma and ocular hypertension: patient considerations

PubMed Central

Suzuki, Emilio Rintaro; Suzuki, Cibele Lima Belico

2010-01-01

Travoprost is a prostaglandin analog used in the management of glaucoma and ocular hypertension for reducing intraocular pressure (IOP). The IOP-lowering efficacy of travoprost has been shown to be similar to that of other prostaglandins, including latanoprost and bimatoprost. When compared with fixed combinations of timolol and either latanoprost or dorzolamide, travoprost alone can reduce mean IOP in a similar or superior manner. Concomitant therapy of travoprost and timolol can reach even greater IOP reductions than fixed combinations at some time points, but with no difference in the early morning, when IOP is usually higher. In addition, the long duration of action of travoprost can also provide better control of IOP fluctuation, probably due to its stronger prostaglandin F receptor mechanism. The side effects of travoprost do not represent a risk to the vision or health of the patient. The proven efficacy and safety combined with convenient once-daily dosing for travoprost increases patient compliance with treatment for glaucoma. PMID:21060666

Intraocular pressure change over a habitual 24-hour period after changing posture or drinking water and related factors in normal tension glaucoma.

PubMed

Sakata, Rei; Aihara, Makoto; Murata, Hiroshi; Saito, Hitomi; Iwase, Aiko; Yasuda, Noriko; Araie, Makoto

2013-08-07

We investigated the correlation between 24-hour IOP in the habitual (sitting during day and supine during night) position (H24h-IOP) and IOP after a postural-change test (PCT-IOP) and a water-drinking test (WDT-IOP). We also investigated ocular and systemic factors related with them in patients with normal tension glaucoma (NTG). Japanese NTG patients underwent H24h-IOP, PCT-IOP, and WDT-IOP measurements during a 24-hour period. Correlations among H24h-IOP, PCT-IOP, and WDT-IOP, and contributing ocular/systemic factors were investigated using regression analysis. There were 33 patients included. Peak H24h-IOP correlated positively with peak PCT-IOP and peak WDT-IOP (estimate = 0.422 and 0.419, P ≤ 0.010), and peak PCT-IOP with WDT-IOP (0.44, P = 0.002). Peak H24h-IOP correlated with refraction (0.36, P = 0.048) and negatively with the mean deviation (MD, -0.066, P = 0.031). MD and baseline IOP (the mean of H24h-IOP) correlated negatively with the H24h-IOP fluctuation (-0.058 and -0.58, P ≤ 0.050). Refraction, baseline IOP, mean blood pressure (mBP), and body mass index (BMI) correlated with peak PCT-IOP (0.23, 0.52, 0.097, and 0.32, respectively, P ≤ 0.038). PCT-IOP difference correlated with refraction and mBP (0.31 and 0.093, P ≤ 0.016) and negatively with age (-0.069, P = 0.003). Central corneal thickness, baseline IOP, age, and BMI correlated with peak WDT-IOP (0.030, 0.40, 0.088, and 0.26, P ≤ 0.050). Age and BMI correlated with WDT-IOP difference (0.086 and 0.20, P < 0.032). Positive correlation was found among the peaks of H24h-, PCT-, and WDT-IOP. A worse visual field was associated with higher peak and greater fluctuation of H24h-IOP in NTG. Several ocular/systemic factors were important in interpreting H24h-, PCT-, and WDT-IOP.

Comparison of a travoprost BAK-free formulation preserved with polyquaternium-1 with BAK-preserved travoprost in ocular hypertension or open-angle glaucoma.

PubMed

Gandolfi, Stefano; Paredes, Tania; Goldberg, Ivan; Coote, Michael; Wells, Anthony; Volksone, Lasma; Pillai, Manju R; Stalmans, Ingeborg; Denis, Philippe

2012-01-01

To demonstrate that the intraocular pressure (IOP)-lowering effect of travoprost 0.004% preserved with polyquaternium-1 (travoprost benzalkonium chloride [BAK]-free) is non-inferior to that of travoprost 0.004% preserved with benzalkonium chloride (travoprost BAK) in patients with ocular hypertension or open-angle glaucoma. A total of 371 patients randomly received travoprost BAK-free (n=185) or travoprost BAK (n=186) dosed once daily in the evening for 3 months. Patients were evaluated at 9 am, 11 AM, and 4 PM at baseline, weeks 2 and 6, and month 3. Intraocular pressure was also evaluated 36 and 60 hours after the month 3 visit. Travoprost BAK-free is non-inferior to travoprost BAK. The 95% upper confidence limits for the difference in mean IOP at month 3 (primary efficacy) were 0.5 mmHg, 0.6 mmHg, and 0.5 mmHg, at 9 AM, 11 AM, and 4 PM, respectively. Mean IOP reductions from baseline ranged from 7.6 to 8.7 mmHg in the travoprost BAK-free group and from 7.7 to 9.2 mmHg in the travoprost BAK group. At 36 and 60 hours after the last dose, mean IOP remained 6.8 mmHg and 5.7 mmHg below baseline in the travoprost BAK-free group, vs 7.3 mmHg and 6.0 mmHg in the travoprost BAK group, respectively. The safety profile of travoprost BAK-free was similar to that of travoprost BAK. Travoprost BAK-free safely and effectively lowers IOP in eyes with open-angle glaucoma or ocular hypertension. This BAK-free formulation has comparable safety, efficacy, and duration of IOP-lowering effect to travoprost preserved with BAK. Travoprost BAK-free is an effective option for IOP reduction while avoiding BAK exposure.

Optic nerve head blood flow response to reduced ocular perfusion pressure by alteration of either the blood pressure or intraocular pressure.

PubMed

Wang, Lin; Cull, Grant A; Fortune, Brad

2015-04-01

To test the hypothesis that blood flow autoregulation in the optic nerve head has less reserve to maintain normal blood flow in the face of blood pressure-induced ocular perfusion pressure decrease than a similar magnitude intraocular pressure-induced ocular perfusion pressure decrease. Twelve normal non-human primates were anesthetized by continuous intravenous infusion of pentobarbital. Optic nerve blood flow was monitored by laser speckle flowgraphy. In the first group of animals (n = 6), the experimental eye intraocular pressure was maintained at 10 mmHg using a saline reservoir connected to the anterior chamber. The blood pressure was gradually reduced by a slow injection of pentobarbital. In the second group (n = 6), the intraocular pressure was slowly increased from 10 mmHg to 50 mmHg by raising the reservoir. In both experimental groups, optic nerve head blood flow was measured continuously. The blood pressure and intraocular pressure were simultaneously recorded in all experiments. The optic nerve head blood flow showed significant difference between the two groups (p = 0.021, repeat measures analysis of variance). It declined significantly more in the blood pressure group compared to the intraocular pressure group when the ocular perfusion pressure was reduced to 35 mmHg (p < 0.045) and below. There was also a significant interaction between blood flow changes and the ocular perfusion pressure treatment (p = 0.004, adjusted Greenhouse & Geisser univariate test), indicating the gradually enlarged blood flow difference between the two groups was due to the ocular perfusion pressure decrease. The results show that optic nerve head blood flow is more susceptible to an ocular perfusion pressure decrease induced by lowering the blood pressure compared with that induced by increasing the intraocular pressure. This blood flow autoregulation capacity vulnerability to low blood pressure may provide experimental evidence related to the

Characterization of ocular biometrics and aqueous humor dynamics in primary angle closure suspects.

PubMed

Guo, Li; Deng, Yuan; Fang, Li; Liu, Chaoqi; Guo, Tao

2017-02-01

Detailed characterizations of ocular biometrics and parameters of aqueous humor dynamics are lacking in primary angle closure suspect (PACS) patients. This study aims to characterize these parameters and compare them with age-matched healthy volunteers.Elderly healthy volunteers (60.6 ± 7.2 years of age, mean ± SD, n = 28) and PACS patients (64.1 ± 11.6 years, n = 30) completed the study. Parameters investigated were axial length (AXL), anterior chamber depth (ACD), anterior chamber volume (ACV), central cornea thickness (CCT), intraocular pressure (IOP), aqueous flow (Fa), outflow facility (C), episcleral venous pressure (EVP), and uveoscleral outflow (Fu). Comparisons and correlations were made between and within groups.In healthy volunteers, ocular biometric parameters, IOP, and EVP correlated very well between the 2 eyes of each individual, but Fa, C, and Fu were not significantly correlated. Biometric parameters of the PACS group significantly (P < 0.001) differed from those of the healthy controls: AXL (23.31 ± 1.03 mm [PACS] vs 22.39 ± 1.04 mm [Control]; mean ± SD), ACD (2.44 ± 0.33 mm [PACS] vs 1.86 ± 0.25 mm [Control]), ACV (136.0 ± 36.1 μL [PACS] vs 81.4 ± 21.8 μL [Control]), CCT (526.9 ± 37.0 μm [PACS] vs 556.1 ± 28.4 μm [Control]). There was no significant change in IOP, Fa, C, EVP, or Fu between Control and PACS. Furthermore, IOP showed no significant correlations with AXL, ACD, ACV, CCT, or C in both groups.The PACS eyes had a shorter AXL, a shallower ACD, and a smaller ACV, but a thicker CCT. Despite these morphological changes, the PACS eyes did not have any significant changes in IOP, and aqueous humor dynamics parameters. This is consistent with the findings that IOP did not show significant correlations with biometrics, or C.

Multicenter clinical trial of high-intensity focused ultrasound treatment in glaucoma patients without previous filtering surgery.

PubMed

Aptel, Florent; Denis, Philippe; Rouland, Jean-François; Renard, Jean-Paul; Bron, Alain

2016-08-01

To evaluate the efficacy and safety of the ultrasonic circular cyclocoagulation procedure in patients with open-angle glaucoma naïve of previous filtering surgery. Prospective non-comparative interventional clinical study conducted in five French University Hospitals. Thirty eyes of 30 patients with open-angle glaucoma, intra-ocular pressure (IOP) > 21 mmHg and with no previous filtering glaucoma surgeries were sonicated with a probe comprising six piezoelectric transducers. The six transducers were activated with a 6-s exposure time. Complete ophthalmic examinations were performed before the procedure and at 1 day, 1 week, 1, 2, 3, 6 and 12 months after the procedure. Primary outcomes were qualified surgical success (defined as IOP reduction from baseline ≥20% and IOP > 5 mmHg with possible re-intervention and without hypotensive medication adjunction) and complete surgical success (defined as IOP reduction from baseline ≥20%, IOP > 5 mmHg and IOP < 21 mmHg with possible re-intervention and without hypotensive medication adjunction) at the last follow-up visit and vision-threatening complications. Secondary outcomes were mean IOP at each follow-up visit compared with baseline, medication use, complications and re-interventions. Intra-ocular pressure was significantly reduced (p < 0.05) from a mean pre-operative value of 28.2 ± 7.2 mmHg (n = 3.6 hypotensive medications) to 19.6 ± 7.9 mmHg at 12 months (n = 3.1 hypotensive medications and n = 1.1 procedures) (mean IOP reduction of 30%). Qualified success was achieved in 63% of eyes (19/30) (mean IOP reduction of 37% in these eyes) and complete success in 46.7% of eyes (14/30) (mean IOP reduction of 37% in these eyes) at the last follow-up. No major intra- or post-operative complications occurred. The UC(3) procedure seems to be an effective and well-tolerated method to reduce IOP in patients with open-angle glaucoma without previous filtering surgery. © 2015 Acta Ophthalmologica

Effect of general anesthetics on IOP in rats with experimental aqueous outflow obstruction.

PubMed

Jia, L; Cepurna, W O; Johnson, E C; Morrison, J C

2000-10-01

To determine the effect of several common general anesthetics on intraocular pressure (IOP) after experimental aqueous outflow obstruction in the rat. A single episcleral vein injection of hypertonic saline was used to sclerose aqueous humor outflow pathways and produce elevated IOP in Brown Norway rats. Animals were housed in either standard lighting or a constant low-level light environment. Awake IOPs were determined using a TonoPen (Mentor, Norwell, MA) immediately before induction of anesthesia by either isoflurane, ketamine, or a mixture of injectable anesthetics (xylazine, ketamine, and acepromazine). For each anesthetic, IOPs were measured immediately after adequate sedation (time 0) and at 5-minute intervals, up to 20 minutes. RESULTS; Awake IOPs ranged from 18 to 52 mm Hg. All anesthetics resulted in a statistically significant (P: < 0.01) reduction in measured IOP at every duration of anesthesia when compared with the corresponding awake IOP. With increasing duration of anesthesia, measured IOP decreased approximately linearly for both the anesthetic mixture and isoflurane. However, with ketamine, IOP declined to 48% +/- 11% (standard lighting) and 60% +/- 7% (constant light) of awake levels at 5 minutes of anesthesia, where it remained stable. In fellow eyes, the SD of the mean IOP in animals under anesthesia was always greater than the corresponding SD of the awake mean. Anesthesia's effects in normal eyes and eyes with elevated IOP were indistinguishable. All anesthetics resulted in rapid and substantial decreases in IOP in all eyes and increased the interanimal variability in IOPs. Measurement of IOP in awake animals provides the most accurate documentation of pressure histories for rat glaucoma model studies.

Oral Omega-3 Supplementation Lowers Intraocular Pressure in Normotensive Adults.

PubMed

Downie, Laura Elizabeth; Vingrys, Algis Jonas

2018-05-01

Elevated intraocular pressure (IOP) is the major modifiable risk factor for the sight-threatening eye disease, glaucoma. We investigated whether oral omega-3 supplements affect IOP in normotensive adults. We undertook a pooled analysis of data from two double-masked, placebo-controlled randomized trials (Australian New Zealand Clinical Trials Registry, ACTRN12614001019695, ACTRN12615000173594) that investigated the efficacy and safety of oral omega-3 supplementation for treating ocular surface inflammation. Recruitment involved adults ( n = 105) with IOP <21 mm Hg, and without a current or prior glaucoma diagnosis. Participants were randomly allocated to either an oral omega-3 (∼1000 mg/day eicosapentaenoic acid + ∼500 mg/day docosahexaenoic acid ± 900 mg/day α-linolenic acid) or placebo (olive oil, 1500 mg/day) supplement. IOP was quantified at baseline and after 3 months of supplementation (day 90). Change in IOP, relative to baseline, was compared between groups. At baseline, participants were of similar age (omega-3/placebo groups: mean ± SEM, 33.7 ± 1.7, n = 72/35.6 ± 3.0 years, n = 33), sex (65%/79% female), and had similar IOP (14.3 ± 0.3/13.8 ± 0.5 mm Hg). At day 90, IOP was reduced to 13.6 ± 0.3 mm Hg in the omega-3 group; controls had a slight IOP increase to 14.2 ± 0.4 mm Hg ( P < 0.05). Oral omega-3 supplementation for 3 months significantly reduced IOP in normotensive adults. To our knowledge, this is the first study to report that omega-3 fatty acids lower IOP in humans. These findings justify further investigation into the therapeutic potential of omega-3 supplementation for reducing IOP, to prevent and/or treat conditions with IOP elevation, including ocular hypertension and glaucoma.

Superselective intra-arterial chemotherapy in the primary management of advanced intra-ocular retinoblastoma: first 4-year experience from a single institution in Turkey.

PubMed

Tuncer, Samuray; Sencer, Serra; Kebudi, Rejin; Tanyıldız, Burak; Cebeci, Zafer; Aydın, Kubilay

2016-11-01

To report our 4-year experience in Turkey, with advanced intra-ocular retinoblastoma managed primarily with intra-arterial chemotherapy (IAC). From October 2011 to September 2015, 26 group D eyes of 24 treatment-naïve retinoblastoma patients managed primarily with IAC were evaluated in this prospective study. Of 76 procedures, ophthalmic artery cannulation failed in two patients with unilateral involvement. In the remaining 22 patients (24 eyes), the mean age at diagnosis was 18 months (range, 6-55 months). Each eye received a mean of 3 IAC sessions/eye (range, 2-5 sessions). After a median follow-up of 29 months (range, 6-55 months), complete regression of the main tumour was achieved in 23 of 24 eyes. One eye with partial regression required enucleation due to ciliary body involvement by the tumour. Overall, 16 eyes (66.6%) were salvaged with primary IAC with or without additional local treatments, and eight (33.3%) required enucleation. The main IAC-related periocular complications included transient eyelid oedema (n = 13), ptosis (n = 6) and forehead hyperpigmentation (n = 3), each resolving in 2 weeks to 4 months. Intra-ocular complications included chorioretinal atrophy (n = 9), newly noted retinal detachment (n = 5) and vitreous haemorrhage (n = 1). Kaplan-Meier eye estimates of enucleation-free survival rates were 83.3% (95% CI, 68.4-98.1%), 69.1% (95% CI, 49.8-88.3%) and 62.9 (95% CI, 41.9-83.8%) at 6 months, 1 and 2 years, respectively, and stable thereafter. Our first 4-year experience in Turkey showed that enucleation or external-beam radiotherapy could be avoided in two-thirds of eyes with advanced intra-ocular retinoblastoma managed primarily with IAC. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The utilization of an ocular wound chamber on corneal epithelial wounds

PubMed Central

McDaniel, Jennifer S; Holt, Andrew W; Por, Elaine D; Eriksson, Elof; Johnson, Anthony J; Griffith, Gina L

2018-01-01

Purpose Currently available ocular moisture chambers are not adequate to manage the treatment of periocular burns, corneal injuries, and infection. The purpose of these studies was to demonstrate that a flexible, semi-transparent ocular wound chamber device adapted from technology currently used on dermal wounds is safe for use on corneal epithelial injuries. Materials and methods A depilatory cream (Nair™, 30 seconds) was utilized to remove the excess hair surrounding the left eyes of anesthetized Institute Armand Frappier (IAF) hairless, female guinea pigs (Crl:HA-Hrhr). A 4 mm corneal epithelium defect was created using a corneal rust ring remover (Algerbrush®II). Epithelial defects were either left untreated or the eyes were fitted with an ocular wound chamber and 0.5 mL of hydroxypropyl methylcellulose (HPMC) gel (GenTeal®) or HPMC liquid (GenTeal®) was injected into each chamber (N=5 per group). At 0, 24, 48, and 72 hours fluorescein and optical coherence tomography imaging was collected and the intraocular pressure (IOP) was measured. H&E staining was performed on corneal and eyelid skin samples and evaluated by a veterinary pathologist. Results Corneal epithelial wounds demonstrated 100% closure rates when left untreated or treated with an ocular wound chamber containing HPMC gel at 72 hours while wounds treated with an ocular wound chamber containing HPMC liquid were 98% healed. No significant differences were found in corneal thickness and wound healing, IOP, or eyelid skin pathology in any treatment group when compared to controls. Conclusions This study indicates that adapted wound chamber technology can be safely used on sterile, corneal epithelial wounds without adverse effects on periocular or ocular tissue when filled with a liquid or gel. PMID:29785086

Surgical outcomes after application of a liquid adhesive ocular bandage to clear corneal incisions during cataract surgery.

PubMed

Uy, Harvey S; Kenyon, Kenneth R

2013-11-01

To compare the anatomic and refractive outcomes in eyes having phacoemulsification with 1 of 3 clear corneal incision (CCI) closure methods. Ambulatory surgical center, Makati, Philippines. Prospective randomized clinical trial. Patients having phacoemulsification cataract surgery had wound closure using no additional treatment (control), a single 10-0 nylon suture, or a liquid adhesive ocular bandage (Ocuseal). The main outcome measures were wound-edge closure rates, surgically induced astigmatism (SIA), foreign-body sensation, and intraocular pressure (IOP) 1, 3, 5, 7, and 14 days postoperatively. The study evaluated 90 eyes. There was a significant improvement in wound-edge closure rates in the suture group and the ocular bandage group compared with the control group (P<.001). A significant increase in SIA occurred in the sutured group but not in the control or ocular bandage groups (P<.001). The ocular bandage group had significantly less foreign-body sensation than the control and suture groups (P<.001). There were no significant differences in IOP between the groups (P=.515). The liquid adhesive ocular bandage resulted in improved wound-edge closure, reduced SIA, and diminished foreign-body sensation. Suturing was associated with improved wound-edge closure but increased SIA and foreign-body sensation. Unsutured incisions led to delayed wound-edge closure and increased foreign-body sensation. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Intraocular Pressure, Tear Production, and Ocular Echobiometry in Guinea Pigs (Cavia porcellus)

PubMed Central

Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Sadjadi, Reza; Azizi, Farzaneh

2016-01-01

The purpose of this study was to evaluate intraocular pressure (IOP) by means of rebound tonometry, to assess tear production by using the endodontic absorbent paper point tear test (EAPTT) and phenol red thread test (PRTT), and to determine the effects of time of day on IOP and tear production in guinea pigs. The study population comprised 24 healthy adult guinea pigs (12 male, 12 female; 48 eyes) of different breeds and ranging in age from 12 to 15 mo. IOP and tear production were measured at 3 time points (0700, 1500, and 2300) during a 24-h period. Overall values (mean ± 1 SD) were: IOP, 6.81 ± 1.41 mm Hg (range, 4.83 to 8.50); PRTT, 14.33 ± 1.35 mm (range, 12.50 to 16.83); and EAPTT, 8.54 ± 1.08 mm (range, 7.17 to 10.0 mm). In addition, ultrasound biometry was performed by using a B-mode system with linear 8-MHz transducer. This study reports reference values for IOP and tear production in guinea pigs. PMID:27423156

Intra-gastric pressures in neonates receiving bubble CPAP.

PubMed

Tyagi, Prashant; Gupta, Neeraj; Jain, Akanksha; Upadhyay, Pramod; Puliyel, Jacob

2015-02-01

To study intra-gastric pressures in neonates receiving bubble continuous positive airway pressure (BCPAP) by nasopharyngeal prong. Twenty seven neonates were recruited for the study. BCPAP pressure of 6 cm water was used in all the neonates. A pressure sensor attached to orogastric tube, measured the intra-gastric pressure prior to starting BCPAP and again between 30 and 90 min of BCPAP. The clinical variables like Downe's score, oxygen saturation, venous blood gas pH, pCO(2) and abdominal girth were recorded alongside with pressure readings. BCPAP resulted in improvement (p < 0.05) in parameters of respiratory distress such as Downe's score (DS), oxygen saturation (SpO(2)) and venous blood gas parameters (pH, pCO(2)). There was no statistical significant increase in intra-gastric pressures (p = 0.834). There were no gastrointestinal complications; abdominal distention, necrotising enterocolitis or gastric perforation during the study. Nasopharyngeal BCPAP at 6 cm of water pressure is an effective modality of treating babies with respiratory distress and the present study shows that it is not associated with a significant rise in intra-gastric pressures.

Ocular Purine Receptors as Drug Targets in the Eye

PubMed Central

Civan, Mortimer M.

2016-01-01

Abstract Agonists and antagonists of various subtypes of G protein coupled adenosine receptors (ARs), P2Y receptors (P2YRs), and ATP-gated P2X receptor ion channels (P2XRs) are under consideration as agents for the treatment of ocular diseases, including glaucoma and dry eye. Numerous nucleoside and nonnucleoside modulators of the receptors are available as research tools and potential therapeutic molecules. Three of the 4 subtypes of ARs have been exploited with clinical candidate molecules for treatment of the eye: A1, A2A, and A3. An A1AR agonist is in clinical trials for glaucoma, A2AAR reduces neuroinflammation, A3AR protects retinal ganglion cells from apoptosis, and both A3AR agonists and antagonists had been reported to lower intraocular pressure (IOP). Extracellular concentrations of endogenous nucleotides, including dinucleoside polyphosphates, are increased in pathological states, activating P2Y and P2XRs throughout the eye. P2YR agonists, including P2Y2 and P2Y6, lower IOP. Antagonists of the P2X7R prevent the ATP-induced neuronal apoptosis in the retina. Thus, modulators of the purinome in the eye might be a source of new therapies for ocular diseases. PMID:27574786

Ocular Purine Receptors as Drug Targets in the Eye.

PubMed

Jacobson, Kenneth A; Civan, Mortimer M

2016-10-01

Agonists and antagonists of various subtypes of G protein coupled adenosine receptors (ARs), P2Y receptors (P2YRs), and ATP-gated P2X receptor ion channels (P2XRs) are under consideration as agents for the treatment of ocular diseases, including glaucoma and dry eye. Numerous nucleoside and nonnucleoside modulators of the receptors are available as research tools and potential therapeutic molecules. Three of the 4 subtypes of ARs have been exploited with clinical candidate molecules for treatment of the eye: A 1 , A 2A , and A 3 . An A 1 AR agonist is in clinical trials for glaucoma, A 2A AR reduces neuroinflammation, A 3 AR protects retinal ganglion cells from apoptosis, and both A 3 AR agonists and antagonists had been reported to lower intraocular pressure (IOP). Extracellular concentrations of endogenous nucleotides, including dinucleoside polyphosphates, are increased in pathological states, activating P2Y and P2XRs throughout the eye. P2YR agonists, including P2Y 2 and P2Y 6 , lower IOP. Antagonists of the P2X7R prevent the ATP-induced neuronal apoptosis in the retina. Thus, modulators of the purinome in the eye might be a source of new therapies for ocular diseases.

Diode laser cyclophotocoagulation paves way to a safer trabeculectomy in eyes with medically uncontrollable intraocular pressure.

PubMed

Singh, Kirti; Dangda, Sonal; Ahir, Nitasha; Mutreja, Ankush; Bhattacharyya, Mainak

2017-04-01

High intraocular pressure (IOP) not responding to systemic and topical anti-glaucoma medications renders the eye at risk for both intra- and post-operative complications of glaucoma filtration surgery. Laser cyclophotocoagulation is able to lower IOP in such refractory glaucoma eyes and may make the surgical event safer. This study assessed diode laser cyclophotocoagulation (DLCP) when used as a temporary measure for lowering IOP prior to performing trabeculectomy. This study is a  retrospective analysis of cases planned for trabeculectomy surgery, uncontrolled on maximally tolerable systemic anti-glaucoma medications. They were analysed for response to DLCP in terms of IOP control, vision-related complications, increased inflammation, post-trabeculectomy hypotony and chances of phthisis and ciliary shutdown. Twelve eyes of ten patients aged 35-65 years were identified and all followed up for at least 2 years. One week following DLCP, the IOP (mean ± SD) declined by 51 % from 46.8 ± 5.4 to 22.8 ± 3.3 mmHg. The IOP was further reduced to 15.4 ± 2.7 mmHg at 4 weeks after trabeculectomy; it remained in the mid-teens for a minimum of 2 years in all cases. The mean (±SD) visual acuity improved from 1.4 ± 0.4 to 0.8 ± 0.4 LogMAR equivalents following trabeculectomy. In four eyes, phacoemulsification was performed 5-7 months after trabeculectomy with improvement in best-corrected visual acuity. One patient developed transient hypotony, post-trabeculectomy, which resolved by 6 days. There were no other complications like increased inflammation, prolonged hypotony or suprachoroidal haemorrhage. DLCP is, thus, effective and safe for temporarily controlling IOP; thereby trabeculectomy can be performed in a quieter ocular milieu.

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

PubMed

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

2017-03-01

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

Effect of marihuana on intraocular and blood pressure in glaucoma.

PubMed

Merritt, J C; Crawford, W J; Alexander, P C; Anduze, A L; Gelbart, S S

1980-03-01

Marihuana inhalation was accompanied by increased heart rate and decreased intraocular and blood pressure in 18 subjects with heterogenous glaucomas. The hypotensive effects appeared in 60 to 90 minutes as the decrease in intraocular pressure (IOP) appeared to follow the decrease in blood pressure. In addition to any local effect, the mechanism of lowered to any local effect, the mechanism of lowered IOP may also involve the decreased pressure perfusing the ciliary body vasculature as a result of the peripheral vasodilatory properties of marihuana. Postural hypotension, tachycardia, palpitations, and alterations in mental status occurred with such frequency as to mitigate against the routine used in the general glaucoma population. Our data indicate that further research should be directed to local means of delivering the ocular hypotensive cannabinoid to the glaucomatous eye.

Intra-oral pressure-based voicing control of electrolaryngeal speech with intra-oral vibrator.

PubMed

Takahashi, Hirokazu; Nakao, Masayuki; Kikuchi, Yataro; Kaga, Kimitaka

2008-07-01

In normal speech, coordinated activities of intrinsic laryngeal muscles suspend a glottal sound at utterance of voiceless consonants, automatically realizing a voicing control. In electrolaryngeal speech, however, the lack of voicing control is one of the causes of unclear voice, voiceless consonants tending to be misheard as the corresponding voiced consonants. In the present work, we developed an intra-oral vibrator with an intra-oral pressure sensor that detected utterance of voiceless phonemes during the intra-oral electrolaryngeal speech, and demonstrated that an intra-oral pressure-based voicing control could improve the intelligibility of the speech. The test voices were obtained from one electrolaryngeal speaker and one normal speaker. We first investigated on the speech analysis software how a voice onset time (VOT) and first formant (F1) transition of the test consonant-vowel syllables contributed to voiceless/voiced contrasts, and developed an adequate voicing control strategy. We then compared the intelligibility of consonant-vowel syllables among the intra-oral electrolaryngeal speech with and without online voicing control. The increase of intra-oral pressure, typically with a peak ranging from 10 to 50 gf/cm2, could reliably identify utterance of voiceless consonants. The speech analysis and intelligibility test then demonstrated that a short VOT caused the misidentification of the voiced consonants due to a clear F1 transition. Finally, taking these results together, the online voicing control, which suspended the prosthetic tone while the intra-oral pressure exceeded 2.5 gf/cm2 and during the 35 milliseconds that followed, proved efficient to improve the voiceless/voiced contrast.

Intra-abdominal pressure: an integrative review

PubMed Central

Milanesi, Rafaela; Caregnato, Rita Catalina Aquino

2016-01-01

ABSTRACT There is a growing request for measuring intra-abdominal pressure in critically ill patients with acute abdominal pain to be clarified. Summarizing the research results on measurement of vesical intra-abdominal pressure and analyzing the level of evidence were the purposes of this integrative literature review, carried out based on the databases LILACS, MEDLINE and PubMed, from 2005 to July 2012. Twenty articles were identified, in that, 12 literature reviews, 4 descriptive and exploratory studies, 2 expert opinions, one prospective cohort study and one was an experience report. The vesical intra-abdominal pressure measurement was considered gold standard. There are variations in the technique however, but some common points were identified: complete supine position, in absence of abdominal contracture, in the end of expiration and expressed in mmHg. Most research results indicate keeping the transducer zeroed at the level of the mid-axillary line at the iliac crest level, and instill 25mL of sterile saline. Strong evidence must be developed. PMID:26958978

Comparison of superior vena cava and femoroiliac vein pressure according to intra-abdominal pressure.

PubMed

Ait-Oufella, Hafid; Boelle, Pierre-Yves; Galbois, Arnaud; Baudel, Jean-Luc; Margetis, Dimitri; Alves, Mikael; Offenstadt, Georges; Maury, Eric; Guidet, Bertrand

2012-06-28

Previous studies have shown a good agreement between central venous pressure (CVP) measurements from catheters placed in superior vena cava and catheters placed in the abdominal cava/common iliac vein. However, the influence of intra-abdominal pressure on such measurements remains unknown. We conducted a prospective, observational study in a tertiary teaching hospital. We enrolled patients who had indwelling catheters in both superior vena cava (double lumen catheter) and femoroiliac veins (dialysis catheter) and into the bladder. Pressures were measured from all the sites, CVP, femoroiliac venous pressure (FIVP), and intra-abdominal pressure. A total of 30 patients were enrolled (age 62 ± 14 years; SAPS II 62 (52-76)). Fifty complete sets of measurements were performed. All of the studied patients were mechanically ventilated (PEP 3 cmH20 (2-5)). We observed that the concordance between CVP and FIVP decreased when intra-abdominal pressure increased. We identified 14 mmHg as the best intra-abdominal pressure cutoff, and we found that CVP and FIVP were significantly more in agreement below this threshold than above (94% versus 50%, P = 0.002). We reported that intra-abdominal pressure affected agreement between CVP measurements from catheter placed in superior vena cava and catheters placed in the femoroiliac vein. Agreement was excellent when intra-abdominal pressure was below 14 mmHg.

Effect of Sildenafil Citrate on Intraocular Pressure and Blood Pressure in Human Volunteers

PubMed Central

Gerometta, Rosana; Alvarez, Lawrence J.; Candia, Oscar A.

2011-01-01

Anecdotal reports have suggested that the vasodilator, sildenafil citrate, which evokes its effect via a select inhibition of PDE5, has the potential to increase intraocular pressure (IOP) in some individuals. An ocular hypertensive effect by sildenafil was also recently described in a sheep animal model. In contrast, clinical studies have not found a direct association between sildenafil ingestion (commonly consumed as Viagra) and changes in IOP. However, some such studies also reported no effects of sildenafil on systemic blood pressure (BP) at the time of the IOP determination. Given this surprising result, our purpose was to repeat a study in human volunteers in the city of Corrientes, Argentina to corroborate the effects of sildenafil on human IOP and systemic BP. For the present study, 9 healthy volunteers (male and female, 18 to 74 years old) were selected as subjects after ophthalmic and cardiovascular evaluation indicated that they exhibited normal parameters for their age. In a masked, placebo-controlled study, the subjects ingested 100 mg sildenafil citrate (provided as Vorst from Laboratorios Bernabo, Argentina) in one session, and a placebo on a second separate occasion. IOP was measured with a Goldman applanation tonometer by an ophthalmologist, and BP by a second physician, neither of whom witnessed the tablet ingestion by the volunteers, nor provided with information on the nature of the test compounds. A third individual administered the tablets. The average baseline IOP of this group of 9 was 13.1 ± 0.6 mm Hg. Subsequent to sildenafil ingestion, IOP increased by 26% to 16.5 ± 0.8 mm Hg 60 min later (p< 0.005, as paired data), and returned to control values within 2 hrs. Both systolic and diastolic BP were significantly reduced by sildenafil ingestion. At the point of maximal systemic hypotension (90 min), the systolic and diastolic pressures declined by 15% and 13%, respectively. No significant changes in IOP or BP were recorded after ingestion

Evidence for a GPR18 Role in Diurnal Regulation of Intraocular Pressure

PubMed Central

Miller, Sally; Leishman, Emma; Oehler, Olivia; Daily, Laura; Murataeva, Natalia; Wager-Miller, Jim; Bradshaw, Heather; Straiker, Alex

2016-01-01

Purpose The diurnal cycling of intraocular pressure (IOP) was first described in humans more than a century ago. This cycling is preserved in other species. The physiologic underpinning of this diurnal variation in IOP remains a mystery, even though elevated pressure is indicated in most forms of glaucoma, a common cause of blindness. Once identified, the system that underlies diurnal variation would represent a natural target for therapeutic intervention. Methods Using normotensive mice, we measured the regulation of ocular lipid species by the enzymes fatty acid amide hydrolase (FAAH) and N-arachidonoyl phosphatidylethanolamine phospholipase (NAPE-PLD), mRNA expression of these enzymes, and their functional role in diurnal regulation of IOP. Results We now report that NAPE-PLD and FAAH mice do not exhibit a diurnal cycling of IOP. These enzymes produce and break down acylethanolamines, including the endogenous cannabinoid anandamide. The diurnal lipid profile in mice shows that levels of most N-acyl ethanolamines and, intriguingly, N-arachidonoyl glycine (NAGly), decline at night: NAGly is a metabolite of arachidonoyl ethanolamine and a potent agonist at GPR18 that lowers intraocular pressure. The GPR18 blocker O1918 raises IOP during the day when pressure is low, but not at night. Quantitative PCR analysis shows that FAAH mRNA levels rise with pressure, suggesting that FAAH mediates the changes in pressure. Conclusions Our results support FAAH-dependent NAGly action at GPR18 as the physiologic basis of the diurnal variation of intraocular pressure in mice. PMID:27893106

[Development of a glaucoma microstent with drainage into the suprachoroidal space: fluid mechanical model approach].

PubMed

Guthoff, R F; Schmidt, W; Buss, D; Schultze, C; Ruppin, U; Stachs, O; Sternberg, K; Klee, D; Chichkov, B; Schmitz, K-P

2009-09-01

The purpose of this study was to develop a microstent with valve function, which normalizes the intraocular pressure (IOP) and drains into the suprachoroidal space. In comparison to the subconjunctival space the suprachoroidal space is attributed with less fibroblast colonization and activity. Different glaucoma drainage devices were idealized as tubes and the flow rates were calculated according to Hagen-Poiseuille. The dimensions of the ideal glaucoma implant were modified with respect to an aqueous humor production of 2 microl/min and the different outflow pathways. Specific components of glaucoma drainage devices at the inlet and outlet were not included. The volume flow calculation of the tested glaucoma implants showed that the dimensions of all lumina were too large to prevent postoperative hypotension. A maximum inner tube diameter of 53 microm was calculated for drainage into the suprachoroidal space based on an intra-ocular pressure (IOP) of 20 mmHg. The glaucoma microstent has to guarantee an aqueous humor flow for physiological IOP. An increase of IOP has to be regulated to physiological pressure conditions by the microvalve.

Topical ocular sodium 4-phenylbutyrate rescues glaucoma in a myocilin mouse model of primary open-angle glaucoma.

PubMed

Zode, Gulab S; Bugge, Kevin E; Mohan, Kabhilan; Grozdanic, Sinisa D; Peters, Joseph C; Koehn, Demelza R; Anderson, Michael G; Kardon, Randy H; Stone, Edwin M; Sheffield, Val C

2012-03-01

Mutations in the myocilin gene (MYOC) are the most common known genetic cause of primary open-angle glaucoma (POAG). The purpose of this study was to determine whether topical ocular sodium 4-phenylbutyrate (PBA) treatment rescues glaucoma phenotypes in a mouse model of myocilin-associated glaucoma (Tg-MYOC(Y437H) mice). Tg-MYOC(Y437H) mice were treated with PBA eye drops (n = 10) or sterile PBS (n = 8) twice daily for 5 months. Long-term safety and effectiveness of topical PBA (0.2%) on glaucoma phenotypes were examined by measuring intraocular pressure (IOP) and pattern ERG (PERG), performing slit lamp evaluation of the anterior chamber, analyzing histologic sections of the anterior segment, and comparing myocilin levels in the aqueous humor and trabecular meshwork of Tg-MYOC(Y437H) mice. Tg-MYOC(Y437H) mice developed elevated IOP at 3 months of age when compared with wild-type (WT) littermates (n = 24; P < 0.0001). Topical PBA did not alter IOP in WT mice. However, it significantly reduced elevated IOP in Tg-MYOC(Y437H) mice to the level of WT mice. Topical PBA-treated Tg-MYOC(Y437H) mice also preserved PERG amplitudes compared with vehicle-treated Tg-MYOC(Y437H) mice. No structural abnormalities were observed in the anterior chamber of PBA-treated WT and Tg-MYOC(Y437H) mice. Analysis of the myocilin in the aqueous humor and TM revealed that PBA significantly improved the secretion of myocilin and reduced myocilin accumulation as well as endoplasmic reticulum (ER) stress in the TM of Tg-MYOC(Y437H) mice. Furthermore, topical PBA reduced IOP elevated by induction of ER stress via tunicamycin injections in WT mice. Topical ocular PBA reduces glaucomatous phenotypes in Tg-MYOC(Y437H) mice, most likely by reducing myocilin accumulation and ER stress in the TM. Topical ocular PBA could become a novel treatment for POAG patients with myocilin mutations.

Biomechanical Changes in the Sclera of Monkey Eyes Exposed to Chronic IOP Elevations

PubMed Central

Girard, Michaël J. A.; Suh, J.-K. Francis; Bottlang, Michael; Burgoyne, Claude F.

2011-01-01

Purpose. To characterize scleral biomechanics in both eyes of eight monkeys in which chronic intraocular pressure (IOP) elevation was induced in one eye. Methods. Each posterior sclera was mounted on a pressurization apparatus, IOP was elevated from 5 to 45 mm Hg while the 3D displacements of the scleral surface were measured by speckle interferometry. Finite element (FE) models of each scleral shell were constructed that incorporated stretch-induced stiffening and multidirectionality of the collagen fibers. FE model predictions were then iteratively matched to experimental displacements to extract unique sets of scleral biomechanical properties. Results. For all eyes, the posterior sclera exhibited inhomogeneous, anisotropic, nonlinear biomechanical behavior. Biomechanical changes caused by chronic IOP elevation were complex and specific to each subject. Specifically: (1) Glaucomatous eyes in which the contralateral normal eyes displayed large modulus or thickness were less prone to biomechanical changes; (2) glaucomatous scleral modulus associated with an IOP of 10 mm Hg decreased (when compared with that of the contralateral normal) after minimal chronic IOP elevation; (3) glaucomatous scleral modulus associated with IOPs of 30 and 45 mm Hg increased (when compared with that of the contralateral normal) after moderate IOP elevation; and (4) FE-based estimates of collagen fiber orientation demonstrated no change in the glaucomatous eyes. Conclusions. Significant stiffening of the sclera follows exposure to moderate IOP elevations in most eyes. Scleral hypercompliance may precede stiffening or be a unique response to minimal chronic IOP elevation in some eyes. These biomechanical changes are likely to be the result of scleral extracellular matrix remodeling. PMID:21519033

Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration.

PubMed

Reis, Gustavo Msm; Grigg, John; Chua, Brian; Lee, Anne; Lim, Ridia; Higgins, Ralph; Martins, Alessandra; Goldberg, Ivan; Clement, Colin I

2017-01-01

The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. This is a retrospective study. Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7.

Value and limitations of transpulmonary pressure calculations during intra-abdominal hypertension.

PubMed

Cortes-Puentes, Gustavo A; Gard, Kenneth E; Adams, Alexander B; Faltesek, Katherine A; Anderson, Christopher P; Dries, David J; Marini, John J

2013-08-01

To clarify the effect of progressively increasing intra-abdominal pressure on esophageal pressure, transpulmonary pressure, and functional residual capacity. Controlled application of increased intra-abdominal pressure at two positive end-expiratory pressure levels (1 and 10 cm H2O) in an anesthetized porcine model of controlled ventilation. Large animal laboratory of a university-affiliated hospital. Eleven deeply anesthetized swine (weight 46.2 ± 6.2 kg). Air-regulated intra-abdominal hypertension (0-25 mm Hg). Esophageal pressure, tidal compliance, bladder pressure, and end-expiratory lung aeration by gas dilution. Functional residual capacity was significantly reduced by increasing intra-abdominal pressure at both positive end-expiratory pressure levels (p ≤ 0.0001) without corresponding changes of end-expiratory esophageal pressure. Above intra-abdominal pressure 5 mm Hg, plateau airway pressure increased linearly by ~ 50% of the applied intra-abdominal pressure value, associated with commensurate changes of esophageal pressure. With tidal volume held constant, negligible changes occurred in transpulmonary pressure due to intra-abdominal pressure. Driving pressures calculated from airway pressures alone (plateau airway pressure--positive end-expiratory pressure) did not equate to those computed from transpulmonary pressure (tidal changes in transpulmonary pressure). Increasing positive end-expiratory pressure shifted the predominantly negative end-expiratory transpulmonary pressure at positive end-expiratory pressure 1 cm H2O (mean -3.5 ± 0.4 cm H2O) into the positive range at positive end-expiratory pressure 10 cm H2O (mean 0.58 ± 1.2 cm H2O). Despite its insensitivity to changes in functional residual capacity, measuring transpulmonary pressure may be helpful in explaining how different levels of positive end-expiratory pressure influence recruitment and collapse during tidal ventilation in the presence of increased intra-abdominal pressure and in

Assessment of Intraocular and Systemic Vasculature Pressure Parameters in Simulated Microgravity with Thigh Cuff Countermeasure

NASA Technical Reports Server (NTRS)

Huang, Alex S.; Balasubramanian, Siva; Tepelus, Tudor; Sadda, Jaya; Sadda, Srinivas; Stenger, Michael B.; Lee, Stuart M. C.; Laurie, Steve S.; Liu, John; Macias, Brandon R.

2017-01-01

Changes in vision have been well documented among astronauts during and after long-duration space flight. One hypothesis is that the space flight induced headward fluid alters posterior ocular pressure and volume and may contribute to visual acuity decrements. Therefore, we evaluated venoconstrictive thigh cuffs as a potential countermeasure to the headward fluid shift-induced effects on intraocular pressure (IOP) and cephalic vascular pressure and volumes.

Neuroprotective effects of Lycium barbarum Lynn on protecting retinal ganglion cells in an ocular hypertension model of glaucoma.

PubMed

Chan, Hiu-Chi; Chang, Raymond Chuen-Chung; Koon-Ching Ip, Angel; Chiu, Kin; Yuen, Wai-Hung; Zee, Sze-Yong; So, Kwok-Fai

2007-01-01

Glaucoma is one of the major neurological disorders in eye leading to irreversible blindness in elderly. Increase in intraocular pressure (IOP) has been considered to be the major risk factor for the progressive loss of retinal ganglion cells (RGCs) in retina. While attenuation of IOP has been a major pharmaceutical target, reduction of IOP cannot prevent progressive loss of RGCs. In this regard, urgent need for alternative treatment has to be investigated. Anti-aging medicinal herb Lycium barbarum L. has been used for centuries in Eastern World to protect the eyes and maintain good health. Using an ocular hypertension (OH) model in rat by laser photocoagulation of episcleral and limbal veins, we attempted to investigate whether L. barbarum can promote RGCs survival against elevated IOP. Oral administration of L. barbarum in Sprague-Dawley rats (250-280 g) significantly reduced the loss of RGCs, although elevated IOP was not significantly altered. Rats fed with the 1 mg/kg extract could nearly totally escape from pressure-induced loss of RGCs. In conclusion, this is the first in vivo report showing the therapeutic function of L. barbarum against neurodegeneration in the retina of rat OH model. The results demonstrate that this extract may be a potential candidate for the development of neuroprotective drug against the loss of RGCs in glaucoma.

A new design and application of bioelastomers for better control of intraocular pressure in a glaucoma drainage device.

PubMed

Luong, Quang Minh; Shang, Lei; Ang, Marcus; Kong, Jen Fong; Peng, Yan; Wong, Tina T; Venkatraman, Subbu S

2014-02-01

Glaucoma drainage device (GDD) implantation is an effective method of lowering the intraocular pressure (IOP). Commonly used GDDs can be classified into nonvalved and valved. Although a stable IOP is critical, currently available devices often cause extreme IOP fluctuations: nonvalved GDDs suffer from a risk of hypotony (IOP<5 mmHg), whereas valved GDDs have a higher risk ocular hypertensive (IOP>22 mmHg). It is hypothesized that a GDD with a valve designed to open around the time of onset of the hypertensive phase, would minimize IOP fluctuation. Accordingly, a valve fabricated from a biodegradable polymer poly(L-lactide-co-ϵ-caprolactone) (PLC 70/30) is evaluated in vitro and in vivo. The pressure response is compared with its non-degradable counterpart in in vitro studies of IOP. It is also established that in vitro, the biodegradability of the valve is programmed to occur over 12 weeks. In vivo, a steady and low IOP is achieved with the biodegradable valve and the hypertensive phase is significantly attenuated compared with the commercial device. Fibrotic encapsulation of the device is also minimized with the biodegradable valve in vivo. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Labor on the Intraocular Pressure in Healthy Women.

PubMed

Meshi, Amit; Armarnik, Sharon; Mimouni, Michael; Segev, Fani; Segal, Ori; Kaneti, Hagai; Assia, Ehud I; Geffen, Noa

2017-01-01

To investigate the effect of modern vaginal labor using epidural anesthesia on the intraocular pressure (IOP) and on the mean ocular perfusion pressure (MOPP) in healthy women. In this prospective observational study, eligible candidates were healthy pregnant women for vaginal delivery with epidural anesthesia, with a singleton pregnancy, who were admitted to the delivery room in the first phase of the first stage of labor. Demographic data as well as medical and obstetric history were obtained at baseline, followed by performance of a biomicroscopic examination. IOP, maternal heart rate, systolic blood pressure, and diastolic blood pressure were measured in the first, second and third stages of labor, 24±2 and 48±2 hours postpartum. IOP was not measured during the contraction phase of stage 2. MOPP was expressed as the difference between the arterial blood pressure and the IOP. Measurements were performed throughout the different stages of labor and were compared with baseline values. Thirty healthy white women were enrolled. Four women dropped out due to unexpected cesarean sections. The average age was 31.8±4.7 years. Nineteen participants received oxytocin during delivery. Twenty-three women were placed in a supine position, whereas 3 in a left decubitus position. No statistically significant changes were recorded in IOP (P=0.50) or MOPP (P=0.17) throughout the different stages of vaginal labor in this study. Vaginal delivery under epidural anesthesia is unlikely to cause significant damage to the optic nerve in healthy women.

Efficacy and tolerability of fixed-combination bimatoprost/timolol versus fixed-combination dorzolamide/brimonidine/timolol in patients with primary open-angle glaucoma or ocular hypertension: a multicenter, prospective, crossover study.

PubMed

García-López, Alfonso; Paczka, José A; Jiménez-Román, Jesús; Hartleben, Curt

2014-12-19

Fixed-combination ocular hypotensives have multiple advantages, but triple-therapy dorzolamide/brimonidine/timolol (dorz/brim/tim) is only available in Latin and South America, and information on its relative efficacy is limited. This study compares the efficacy and tolerability of fixed-combination bimatoprost/timolol (bim/tim) and dorz/brim/tim in Mexican patients with primary open-angle glaucoma or ocular hypertension. In this investigator-masked, crossover study, patients with unmet target intraocular pressure (IOP) on once-daily bim/tim or twice-daily dorz/brim/tim received the opposite medication for 3 months before returning to their pre-baseline medication for 3 months. IOP was evaluated before and after morning instillation at months 2, 3, 5 and 6. Primary endpoints were mean IOP change and Ocular Surface Disease Index© (OSDI) score at each visit. The intent-to-treat population was the a priori analysis population, but due to the number of discontinuations, the per-protocol and intent-to-treat populations were used for the primary efficacy and sensitivity analyses, respectively. Seventy-eight and 56 patients were included in the intent-to-treat and per-protocol populations, respectively. At month 3, statistically significant IOP reductions from baseline were observed in the bim/tim (P < 0.01) and dorz/brim/tim (P < 0.0001) groups, regardless of assessment time. At month 6, patients returned to bim/tim exhibited no significant IOP increase (regardless of assessment time), but patients returned to dorz/brim/tim exhibited a statistically significant IOP increase (P < 0.001) when assessed before instillation of study treatment. Results were similar in both intent-to-treat and per-protocol analysis populations. In the per-protocol analysis, 70% of patients on bim/tim at month 3 had an IOP <14 mm Hg, which declined to 58% (P = 0.0061) at month 6 (ie, after 3 months of dorz/brim/tim treatment). In patients receiving dorz/brim/tim at month 3

The Effect of Dehydration and Fasting on Corneal Biomechanical Properties and Intraocular Pressure.

PubMed

Oltulu, Refik; Satirtav, Gunhal; Ersan, Ismail; Soylu, Erkan; Okka, Mehmet; Zengin, Nazmi

2016-11-01

To evaluate the changes in corneal biomechanical properties and intraocular pressure (IOP) during fasting period in healthy subjects. Seventy-two eyes of 72 fasting subjects (study group), and 62 eyes of 62 nonfasting subjects (control group) were enrolled in this prospective study undertaken at a single university hospital. All subjects underwent complete ophthalmologic examination including ocular biomechanical evaluation with ocular response analyzer. Ocular response analyzer measurement was performed on the right eyes of the subjects between 5.00 and 6.00 PM after approximately 14 hr of fasting for the study group and after a nonfasting period for the control group. The corneal hysteresis, corneal resistance factor, mean corneal compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg) values were measured with a patented dynamic bidirectional applanation process. Goldmann-correlated IOP and IOPcc measurements in the study group and the control group were found as 13.8±2.8 mm Hg, 14.6±2.6 mm Hg and 16.3±2.2 mm Hg, 15.7±2.4 mm Hg, respectively. There was statistically significant difference within the two groups in IOPg and IOPcc (P<0.001). In addition, corneal hysteresis and corneal resistance factor significantly decreased in study group compared with control group (P<0.001, P=0.012, respectively). Prolonged fasting causes a significant decrease in IOPg, IOPcc, corneal hysteresis, and corneal resistance factor in healthy subjects, altering the biomechanical properties of the cornea.

Long-term intraocular pressure changes in patients with neovascular age-related macular degeneration treated with ranibizumab.

PubMed

Menke, Marcel N; Salam, Adzura; Framme, Carsten; Wolf, Sebastian

2013-01-01

To investigate the long-term effects of multiple intravitreal injections (IVTs) of ranibizumab (Lucentis) on intraocular pressure (IOP) in patients with neovascular age-related macular degeneration. In 320 eyes, IOP measurements were performed at baseline prior to injection and compared with IOP measurements of the last visit. Correlations between mean IOP change and total number of IVTs, visual acuity or patient age were tested. The mean IOP increase was 0.8 ± 3.1 mm Hg (p < 0.0001). Seven eyes showed final IOP values between 22 and 25 mm Hg. The mean follow-up was 22.7 ± 14.1 months. No further correlations between IOP change and number of IVTs, visual acuity or patient age have been found. This study demonstrated a statistically significant IOP increase in patients treated with repeated injections of ranibizumab. However, IOP increase required no glaucoma treatment during the study. Therefore, repeated injections with ranibizumab can be considered safe with regard to long-term IOP changes in patients without ocular hypertension or glaucoma. Copyright © 2013 S. Karger AG, Basel.

Correlation Between Biomechanical Responses of Posterior Sclera and IOP Elevations During Micro Intraocular Volume Change

PubMed Central

Morris, Hugh J.; Tang, Junhua; Cruz Perez, Benjamin; Pan, Xueliang; Hart, Richard T.; Weber, Paul A.; Liu, Jun

2013-01-01

Purpose. This study tested the hypothesis that intraocular pressure (IOP) elevations, induced by controlled increase of intraocular volume, are correlated with the biomechanical responses of the posterior sclera. Methods. Porcine globes were tested within 48 hours postmortem. The first group of globes (n = 11) was infused with 15 μL of phosphate-buffered saline at three different rates to investigate rate-dependent IOP elevations. The second group (n = 16) was first infused at the fast rate and then underwent inflation tests to investigate the relationship between IOP elevations (ΔIOP) and scleral strains. The strains in the superotemporal region of the posterior sclera were measured by ultrasound speckle tracking. Linear regression was used to examine the association between ΔIOP due to micro-volumetric infusion and the scleral strains at a specific inflation pressure. Results. The average ΔIOP was 14.9 ± 4.3 mm Hg for the infusion of 15 μL in 1 second. The ΔIOP was greater for the faster infusion rates but highly correlated across different rates (P < 0.001). A significant negative association was found between the ΔIOP and the tangential strains in both the circumferential (R2 = 0.54, P = 0.003) and meridian (R2 = 0.53, P = 0.002) directions in the posterior sclera. Conclusions. This study showed a substantial increase in IOP, with a large intersubject variance during micro-volumetric change. A stiffer response of the sclera was associated with larger IOP spikes, providing experimental evidence linking corneoscleral biomechanics to IOP fluctuation. In vivo measurement of corneoscleral biomechanics may help better predict the dynamic profile of IOP. PMID:24130185

Reduction of enhanced rabbit intraocular pressure by instillation of pyroglutamic acid eye drops.

PubMed

Ito, Yoshimasa; Nagai, Noriaki; Okamoto, Norio; Shimomura, Yoshikazu; Nakanishi, Kunio; Tanaka, Ryuichiro

2013-01-01

L-Pyroglutamic acid (PGA) is an endogenous molecule derived from l-glutamate. We demonstrate the effects of PGA on intraocular pressure (IOP) in experimentally induced ocular hypertension in rabbits. In the in vitro and in vivo transcorneal penetration studies, the PGA solution (PGA in saline) did not penetrate the rabbit cornea. On the other hand, the penetration of PGA was improved by the addition of zinc chloride and 2-hydroxypropyl-β-cyclodextrin (HPCD), and PGA penetration was enhanced with increasing HPCD concentration. Therefore, PGA solutions containing 0.5% zinc chloride and 5% or 10% HPCD (PGA/HPCD(5% or 10%) eye drops) were used to investigate the effects for IOP in this study. An elevation in IOP was induced by the rapid infusion of 5% glucose solution (15 mL/kg of body weight) through the marginal ear vein or maintaining under dark phase for 5 h. In the both models, the induced elevation in IOP was prevented by the instillation of PGA/HPCD eye drops, and the IOP-reducing effect enhanced with increasing HPCD concentration in the drops. Nitric oxide (NO) levels elevated in the aqueous humor following the infusion of 5% glucose solution, and this increase was also suppressed by the instillation of PGA/HPCD eye drops. In conclusion, the present study demonstrates that the instillation of PGA/HPCD eye drops has an IOP-reducing effect in rabbits with experimentally induced ocular hypertension, probably as a result of the suppression of NO production.

Tonopen XL assessment of intraocular pressure through silicone hydrogel contact lenses.

PubMed

Schornack, Muriel; Rice, Melissa; Hodge, David

2012-09-01

To assess the accuracy of Tonopen XL measurement of intraocular pressure (IOP) through low-power (-0.25 to -3.00) and high power (-3.25 to -6.00) silicone hydrogel lenses of 3 different materials (galyfilcon A, senofilcon A, and lotrafilcon B). Seventy-eight patients were recruited for participation in this study. All were habitual wearers of silicone hydrogel contact lenses, and none had been diagnosed with glaucoma, ocular hypertension, or anterior surface disease. IOP was measured with and without lenses in place in the right eye only. Patients were randomized to initial measurement either with or without the lens in place. A single examiner collected all data. No statistically significant differences were noted between IOP measured without lenses and IOP measured through low-power lotrafilcon B lenses or high-power or low-power galyfilcon A and senofilcon A lenses. However, we did find a statistically significant difference between IOP measured without lenses and IOP measured through high-power lotrafilcon B lenses. In general, Tonopen XL measurement of IOP through silicone hydrogel lenses may be sufficiently accurate for clinical purposes. However, Tonopen XL may overestimate IOP if performed through a silicone hydrogel lens of relatively high modulus.

Prospective Observational Post-Marketing Study of Tafluprost for Glaucoma and Ocular Hypertension: Effectiveness and Treatment Persistence.

PubMed

Kuwayama, Yasuaki; Hashimoto, Masako; Kakegawa, Reiko; Nomura, Akio; Shimada, Fumiki

2017-06-01

The aim of this study was to investigate the long-term intraocular pressure (IOP)-lowering effect and safety of tafluprost, a prostaglandin analogue, in actual clinical practice and to determine persistency of tafluprost as an indicator of its benefit-risk balance. This was a large-scale, post-marketing, multicenter, non-interventional, open-label, long-term study. Patients with glaucoma or ocular hypertension who initiated tafluprost treatment were registered and prospectively observed over a 2-year period in the real-world setting in Japan. Long-term IOP and safety data were collected. Of the 4502 patients registered from 553 medical institutions, 4265 patients were analyzed. The majority of patients had normal-tension glaucoma (44.4%) and primary open-angle glaucoma (37.8%), and patients with ocular hypertension constituted 7.0%. Treatment patterns with tafluprost during the study period were as follows: naïve monotherapy (48.1%), switching monotherapy (18.4%), and concomitant therapy (33.5%). In all patients analyzed, mean IOP was significantly reduced from 18.6 ± 5.9 mmHg (month 0) to 15 mmHg or below throughout the 2-year observation period after initiation of tafluprost. Significant IOP-lowering effects were shown in various treatment patterns and disease types. Adverse reactions were observed in 795 patients (18.64%). Major adverse reactions included eyelid pigmentation, ocular hyperemia, eyelash changes, eyelid hypertrichosis, and iris hyperpigmentation. Kaplan-Meier curves showed that 84.6% and 76.1% of patients were persistent on tafluprost for 1 and 2 years, respectively, when discontinuation due to insufficient efficacy or adverse events was defined as a treatment failure event. Furthermore, among treatment-naïve patients (n = 2304), the persistency rates on tafluprost monotherapy were 77.0% for 1 year and 67.0% for 2 years. Tafluprost showed significant long-term IOP-lowering effects regardless of treatment patterns or diagnosis, with

Effect of sildenafil citrate on intraocular pressure and blood pressure in human volunteers.

PubMed

Gerometta, Rosana; Alvarez, Lawrence J; Candia, Oscar A

2011-07-01

Anecdotal reports have suggested that the vasodilator, sildenafil citrate, which evokes its effect via a select inhibition of PDE5, has the potential to increase intraocular pressure (IOP) in some individuals. An ocular hypertensive effect by sildenafil was also recently described in a sheep animal model. In contrast, clinical studies have not found a direct association between sildenafil ingestion (commonly consumed as Viagra) and changes in IOP. However, some such studies also reported no effects of sildenafil on systemic blood pressure (BP) at the time of the IOP determination. Given this surprising result, our purpose was to repeat a study in human volunteers in the city of Corrientes, Argentina to corroborate the effects of sildenafil on human IOP and systemic BP. For the present study, 9 healthy volunteers (male and female, 18-74 years old) were selected as subjects after ophthalmic and cardiovascular evaluation indicated that they exhibited normal parameters for their age. In a masked, placebo-controlled study, the subjects ingested 100 mg sildenafil citrate (provided as Vorst from Laboratorios Bernabo, Argentina) in one session, and a placebo on a second separate occasion. IOP was measured with a Goldman applanation tonometer by an ophthalmologist, and BP by a second physician, neither of whom witnessed the tablet ingestion by the volunteers, nor provided with information on the nature of the test compounds. A third individual administered the tablets. The average baseline IOP of this group of 9 was 13.1 ± 0.6 mm Hg. Subsequent to sildenafil ingestion, IOP increased by 26% to 16.5 ± 0.8 mm Hg 60 min later (P < 0.005, as paired data), and returned to control values within 2 h. Both systolic and diastolic BP were significantly reduced by sildenafil ingestion. At the point of maximal systemic hypotension (90 min), the systolic and diastolic pressures declined by 15% and 13%, respectively. No significant changes in IOP or BP were recorded after

Risk of Ocular Hypertension in Adults with Non-infectious Uveitis

PubMed Central

Daniel, Ebenezer; Pistilli, Maxwell; Kothari, Srishti; Khachatryan, Naira; Kaçmaz, R. Oktay; Gangaputra, Sapna S.; Sen, H. Nida; Suhler, Eric B.; Thorne, Jennifer E.; Foster, C. Stephen; Jabs, Douglas A.; Nussenblatt, Robert B.; Rosenbaum, James T.; Levy-Clarke, Grace A.; Bhatt, Nirali P.; Kempen, John H.

2017-01-01

Objective To describe the risk and risk factors for ocular hypertension (OHT) in adults with non-infectious uveitis. Design Retrospective, multicenter, cohort study. Participants Patients aged ≥ 18 years with non-infectious uveitis seen between 1979 and 2007 at 5 tertiary uveitis clinics. Methods Demographic, ocular and treatment data were extracted from medical records of uveitis cases. Main outcome measures Prevalent and incident OHT with intraocular pressures (IOP) of ≥21 mmHg, ≥30mmHg and rise of ≥10 mmHg from documented IOP recordings (or use of treatment for OHT). Results Among 5270 uveitic eyes of 3308 patients followed for OHT, the mean annual incidence rates for OHT ≥21mmHg and OHT ≥30mmHg are 14.4% (95%CI: 13.4%, 15.5%) and 5.1% (95% CI: 4.7%, 5.6%) per year, respectively. Statistically significant risk factors for incident OHT ≥30mmHg included: systemic hypertension (adjusted hazard ratio (aHR) = 1.29); worse presenting visual acuity (20/200 or worse vs 20/40 or better, aHR = 1.47); pars plana vitrectomy (aHR = 1.87); prior history of OHT in the other eye: IOP ≥ 21 mmHg (aHR = 2.68), ≥30 mmHg (aHR=4.86), and prior/current use of IOP-lowering drops or surgery in the other eye (aHR = 4.17); anterior chamber cells: 1+ (aHR = 1.43) and ≥2+ (aHR = 1.59) vs none; epiretinal membrane (aHR=1.25); peripheral anterior synechiae (aHR = 1.81); current use of prednisone>7.5 mg/day (aHR = 1.86); periocular corticosteroids in the last three months (aHR = 2.23); current topical corticosteroid use [≥ 8X/day vs. none] (aHR=2.58); and prior use of fluocinolone acetonide implants (aHR = 9.75). Bilateral uveitis (aHR = 0.69) and previous hypotony (aHR=0.43) were associated with statistically significantly lower risk of OHT. Conclusions OHT is sufficiently common in eyes treated for uveitis that surveillance for OHT is essential at all visits for all cases. Patients with one or more of the several risk factors identified are at particularly high risk

Experimental observation of intraocular pressure changes during microkeratome suctioning in laser in situ keratomileusis.

PubMed

Bissen-Miyajima, Hiroko; Suzuki, Shintaro; Ohashi, Yoshie; Minami, Keiichiro

2005-03-01

To observe changes in intraocular pressure (IOP), the manner in which the eye is suctioned, and the effect of the number of suction ports. Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, Japan. Suction rings with single or dual ports were made of transparent acrylic acid resin to facilitate observation with a digital video camera. The IOP and the duration of the IOP increase (time to reach 90% of the maximum IOP) were measured in 6 porcine eyes with an intra-vein pressure-sensor catheter in the vitreous cavity. The IOP changes were recorded using a personal computer. Suctioning with single- and dual-port suction rings was similar. The IOP increases with single- and dual-port suction rings were similar (99.1 mm Hg +/- 6.1 [SD] and 99.0 +/- 6.5 mm Hg, respectively) (P=.987). The duration of the IOP increase was also similar (4.21 +/- 0.24 seconds and 4.12 +/- 0.33 seconds, respectively) (P=.190). The number of ports did not affect suctioning and changes in IOP. This technique is useful in developing the ideal shape and setting of the suction ring.

Effects of 30-Day Head-Down Bed Rest on Ocular Structures and Visual Function in a Healthy Subject

PubMed Central

Taibbi, Giovanni; Kaplowitz, Kevin; Cromwell, Ronita L.; Godley, Bernard F.; Zanello, Susana B.; Vizzeri, Gianmarco

2013-01-01

Introduction We report ocular changes occurring in a healthy human subject enrolled in a bed rest (BR) study designed to replicate the effects of a low-gravity environment. Case report A 25-year-old Caucasian male spent 30 consecutive days in a 6° head-down-tilt position at the NASA Flight Analogs Research Unit. Comprehensive ophthalmologic exams, optic disc stereo-photography, Standard Automated Perimetry (SAP) and optic disc Spectralis OCT scans were performed at baseline, immediately post-BR (BR+0) and 6 months post-BR. Main outcome measures: changes in best-corrected visual acuity, intraocular pressure (IOP), cycloplegic refraction, SAP and Spectralis OCT measures. At BR+0 IOP was 11 and 10 mmHg in the right (OD) and left eye (OS), respectively (a bilateral 4 mmHg decrease compared to baseline); SAP documented a possible bilateral symmetrical inferior scotoma; Spectralis OCT showed an average 19.4 μm (+5.2%) increase in peripapillary retinal thickness, and an average 0.03 mm3 (+5.0%) increase in peripapillary retinal volume bilaterally. However, there were no clinically detectable signs of optic disc edema. 6 months post-BR, IOP was 13 and 14 mmHg in OD and OS, respectively, and the scotoma had resolved. Spectralis OCT measurements matched the ones recorded at baseline. Discussion In this subject, a reduction in IOP associated with subtle structural and functional changes compared to baseline were documented after prolonged head-down BR. These changes may be related to cephalad fluid shifts in response to tilt. Further studies should clarify whether decreased translaminar pressure (i.e., the difference between IOP and intracranial pressure) may be responsible for these findings. PMID:23447853

Efficacy and safety of preservative-free latanoprost eyedrops, compared with BAK-preserved latanoprost in patients with ocular hypertension or glaucoma.

PubMed

Rouland, Jean-François; Traverso, Carlo Enrico; Stalmans, Ingeborg; Fekih, Lamia El; Delval, Laurent; Renault, Didier; Baudouin, Christophe

2013-02-01

To compare efficacy (intraocular pressure (IOP) reduction) and safety of preservative-free latanoprost (T2345) to benzalkonium chloride (BAK)-preserved latanoprost (BPL; Xalatan) in ocular hypertension (OHT) or primary open angle glaucoma (POAG) patients. Prospective, international, multicentre, randomised, investigator-masked, parallel-group trial. After a wash-out period, POAG or OHT patients, previously managed by BPL monotherapy, randomly received T2345 or BPL (one drop into the affected eye(s)) once daily from D0 to D84. Change in IOP was measured at 09:00 (±1 h) from D0 to D84 in the worse eye. Mean IOP reduction (D0-D84) was -8.6±2.6 mm Hg (-36%) on T2345 and -9.0±2.4 mm Hg (-38%) on BPL, confirming non-inferiority of T2345 to BPL. Non-inferiority of T2345 was observed from D15. The most frequent ocular adverse event, drug intolerance, was reported in 1 (0.5%) patient on T2345 versus 4 (2.1%) patients on BPL. Moderate to severe conjunctival hyperaemia was less frequent on T2345 than on BPL at D42 (20.2% vs 30.6%; p=0.003) and D84 (21.4% vs 29.1%; p=0.02). Upon instillation, the global subjective ocular symptom score was significantly lower on T2345 than BPL on D42 (0.15 vs 0.41; p=0.001) and D84 (0.18 vs 0.46; p=0.001). Preservative-free latanoprost has the same efficacy as BPL, with improved local tolerance.

A review of preserved and preservative-free prostaglandin analogues for the treatment of open-angle glaucoma and ocular hypertension.

PubMed

Hommer, A

2010-06-01

Glaucoma affects an increasing number of people worldwide and is the second leading cause of blindness. The aim of antiglaucoma therapy is to maintain a patient's visual function and quality of life. Prostaglandin analogues are first-line topical antiglaucoma therapy. They are effective at lowering intraocular pressure (IOP) and are generally well tolerated, with fewer systemic adverse events compared with the other classes. However, the use of prostaglandin analogues can be associated with ocular adverse effects, such as stinging/burning sensation, dry eyes, iris and periocular hyperpigmentation, and eye lash growth, which can affect patient compliance. Preservatives used in antiglaucoma preparations can have dose-dependent toxic effects, which contribute to adverse effects. The development of preservative-free preparations may reduce such adverse effects and therefore improve patient compliance. Tafluprost is a prostaglandin analogue in a preservative-free formulation that was recently approved for the reduction of elevated IOP in open-angle glaucoma and ocular hypertension. Copyright 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

Regulation of intraocular pressure in mice: structural analysis of dopaminergic and serotonergic systems in response to cabergoline.

PubMed

Platania, Chiara Bianca Maria; Leggio, Gian Marco; Drago, Filippo; Salomone, Salvatore; Bucolo, Claudio

2013-11-01

Elevated intraocular pressure (IOP) is the main recognized risk factor of glaucoma. To investigate the contribution of dopaminergic and serotonergic systems in IOP regulation, we used cabergoline, a mixed dopamine and serotonin agonist, in C57BL/6J WT and dopamine D₃ receptor knock-out (D₃R⁻/⁻) mice with normal eye pressure or steroid-induced ocular hypertension. Furthermore, we studied the structural basis of the cabergoline-mediated activation of the dopaminergic and serotonergic systems by molecular modeling. Topical application of cabergoline, significantly decreased, in a dose-dependent manner, the intraocular pressure in WT mice, both in an ocular normotensive group (-9, -5 and -2 mmHg with 5%, 1%, and 0.1%, respectively) and an ocular hypertensive group, with a prolonged effect in this latter group. No change of intraocular pressure was observed after topical application of cabergoline in D₃R⁻/⁻ mice. We modeled and optimized, with molecular dynamics, structures of hD₃, h5HT(1A) and h5HT(2A-C) receptors; thereafter we carried out molecular docking of cabergoline. Docking revealed that binding of cabergoline into D₃ and 5HT(1A) receptors is associated with a better desolvation energy in comparison to 5HT(2A-C) binding. In conclusion, the present study support the hypothesis that dopaminergic system is pivotal to regulate IOP and that D₃R represents an intriguing target in the treatment of glaucoma. Furthermore, the structure-based computational approach adopted in this study is able to build and refine structure models of homologous dopaminergic and serotonergic receptors that may be of interest for structure-based drug discovery of ligands, with dopaminergic selectivity or with multi-pharmacological profile, potentially useful to treat optic neuropathies. Copyright © 2013 Elsevier Inc. All rights reserved.

Ocular Outcomes Comparison Between 14- and 70-day Head-down Tilt Bed Rest

NASA Technical Reports Server (NTRS)

Cromwell, R.L.; Taibbi, G.; Zanello, S.B.; Yarbough, P.O.; Ploutz-Snyder, R.J.; Vizzen, G.

2015-01-01

INTRODUCTION: Ophthalmological changes, including optic disc edema with optic nerve sheath distension, posterior globe flattening with hyperopic shift, choroidal folds and cotton wool spots have been detected in some astronauts involved in long-duration spaceflights. (sup 1) It is hypothesized that elevated intracranial pressure resulting from microgravity-induced cephalad fluid shifts may be responsible for most of these findings. Head-down tilt bed rest (HTDBR) is a ground-based microgravity analog which also produces cephalad fluid shifts. It is conceivable that prolonged HDTBR exposure may induce ocular changes similar to those experienced in microgravity. Therefore, the purpose of the present study was to compare structural and functional ocular outcomes between 14- and 70-day HDTBR in healthy human subjects. It is hypothesized that 70-d HDTBR induced ocular changes of greater magnitude as compared to 14-d HDTBR. METHODS: Two HDTBR studies were conducted at the NASA Flight Analogs Research Unit, located at The University of Texas Medical Branch at Galveston, TX. Identical NASA standard screening procedures and BR conditions (e.g., strict sleep-wake cycle, standardized diet, continuous video monitoring) were implemented in both studies. Participants spent 14 and/or 70 consecutive days in a 6deg HDT position and did not engage in exercise. Subjects received weekly ocular examinations before, during, and after HDTBR. Ocular testing included: distance and near best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP) measurement, color vision, red dot test, modified Amsler grid test, confrontational visual field, color fundus photography and Spectral-domain OCT scans of the macula and the optic disc. Pre/post HDTBR differences between the two studies will be evaluated for BCVA, spherical equivalent, IOP, retinal nerve fiber layer (RNFL) thickness and macular OCT parameters. RESULTS: 16 (12 males and 4 females) and 6 (5 males and 1

Bimatoprost 0.03%/timolol 0.5% preservative-free ophthalmic solution versus bimatoprost 0.03%/timolol 0.5% ophthalmic solution (Ganfort) for glaucoma or ocular hypertension: a 12-week randomised controlled trial

PubMed Central

Goldberg, Ivan; Gil Pina, Rafael; Lanzagorta-Aresti, Aitor; Schiffman, Rhett M; Liu, Charlie; Bejanian, Marina

2014-01-01

Aim To compare the efficacy and safety of single-dose bimatoprost 0.03%/timolol 0.5% preservative-free (PF) ophthalmic solution with bimatoprost 0.03%/timolol 0.5% ophthalmic solution in patients with open-angle glaucoma or ocular hypertension. Methods In this multicentre, randomised, parallel-group study, patients were randomised to bimatoprost/timolol PF or bimatoprost/timolol once daily in the morning for 12 weeks. Primary efficacy endpoints, reflecting differing regional regulatory requirements, included change from baseline in worse eye intraocular pressure (IOP) in the per-protocol population at week 12, and the average eye IOP at weeks 2, 6 and 12 in the intent-to-treat population. Results 561 patients were randomised (278 to bimatoprost/timolol PF; 283 to bimatoprost/timolol); 96.3% completed the study. Both treatment groups showed statistically and clinically significant mean decreases from baseline in worse eye IOP and in average eye IOP at all follow-up time points (p<0.001). Bimatoprost/timolol PF met all pre-established criteria for non-inferiority and equivalence to bimatoprost/timolol. Ocular adverse events were similar between treatment groups, with conjunctival hyperaemia being the most frequent. Most were mild or moderate in severity. Conclusions Bimatoprost/timolol PF demonstrated non-inferiority and equivalence in IOP lowering compared with bimatoprost/timolol, with no significant differences in safety and tolerability. Trial registration number NCT01177098. PMID:24667994

Surveillance of Ocular Parameters and Visual Function in Bed Rest Subjects

NASA Technical Reports Server (NTRS)

Cromwell, Ronita L.

2011-01-01

Recent visual changes in astronauts have raised concern about ocular health during long duration spaceflight. Seven cases have been documented in astronauts who spent 6 months aboard the International Space Station. These astronauts were male ranging in age from 45 to 55 years old. All astronauts exhibited pre- to post flight refractive changes. Decreased intraocular pressure (IOP) post flight was observed in 3 cases. Fundoscopic exams revealed post flight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and the presence of cotton wool spots in 3 cases. Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema, and also documented retinal nerve fiber layer thickening (5 cases). Findings from MRI examinations showed posterior globe flattening (5 cases), optic nerve sheath distention (6 cases) and torturous optic nerves (2 cases). Of the 7 cases, intracranial pressure was measured on 4 astronauts. These 4 showed elevated ICP post-flight that remained elevated for as long as 19 months in one case. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes seen in astronauts. Head-down tilt bed rest is a spaceflight analog that induces cephalad fluid shifts. This study is designed to provide ocular monitoring of bed rest subjects and determine whether clinically relevant changes are found. Ocular Changes

The effect of increased intra-abdominal pressure on orbital subarachnoid space width and intraocular pressure.

PubMed

Liu, Su-Meng; Wang, Ning-Li; Zuo, Zhen-Tao; Chen, Wei-Wei; Yang, Di-Ya; Li, Zhen; Cao, Yi-Wen

2018-02-01

In accordance with the trans-lamina cribrosa pressure difference theory, decreasing the trans-lamina cribrosa pressure difference can relieve glaucomatous optic neuropathy. Increased intracranial pressure can also reduce optic nerve damage in glaucoma patients, and a safe, effective and noninvasive way to achieve this is by increasing the intra-abdominal pressure. The purpose of this study was to observe the changes in orbital subarachnoid space width and intraocular pressure at elevated intra-abdominal pressure. An inflatable abdominal belt was tied to each of 15 healthy volunteers, aged 22-30 years (12 females and 3 males), at the navel level, without applying pressure to the abdomen, before they laid in the magnetic resonance imaging machine. The baseline orbital subarachnoid space width around the optic nerve was measured by magnetic resonance imaging at 1, 3, 9, and 15 mm behind the globe. The abdominal belt was inflated to increase the pressure to 40 mmHg (1 mmHg = 0.133 kPa), then the orbital subarachnoid space width was measured every 10 minutes for 2 hours. After removal of the pressure, the measurement was repeated 10 and 20 minutes later. In a separate trial, the intraocular pressure was measured for all the subjects at the same time points, before, during and after elevated intra-abdominal pressure. Results showed that the baseline mean orbital subarachnoid space width was 0.88 ± 0.1 mm (range: 0.77-1.05 mm), 0.77 ± 0.11 mm (range: 0.60-0.94 mm), 0.70 ± 0.08 mm (range: 0.62-0.80 mm), and 0.68 ± 0.08 mm (range: 0.57-0.77 mm) at 1, 3, 9, and 15 mm behind the globe, respectively. During the elevated intra-abdominal pressure, the orbital subarachnoid space width increased from the baseline and dilation of the optic nerve sheath was significant at 1, 3 and 9 mm behind the globe. After decompression of the abdominal pressure, the orbital subarachnoid space width normalized and returned to the baseline value. There was no significant difference in the

[Experimental study on ocular hypotensive efficacy of parenteral metoprolol].

PubMed

Onishchenko, A L; Kolbasko, A V; Safronova, M A; Tarash, O S; Dimaksyan, M V

2015-01-01

to evaluate ocular hypotensive efficacy of parenteral metoprolol in an experiment. A total of 3 series of experiments on 24 rabbits were performed. The first series involved a single subconjunctival injection of 0.3 mg of metoprolol in the right eye, while the left served as a control. During the second series the rabbits received 0.5 mg of metoprolol intramuscularly. The third series also implied a subconjunctival injection of 0.3 mg of metoprolol in the right eye, however, supplemented with timolol 0.5% instilled in the left. In all rabbits tonometry was performed before the injection and then in 30 min, 1, 2, 3, 6, 8, and 24 hours. Biomicroscopy and ophthalmoscopy were also performed before and 1, 3, and 7 days after the injection. The maximum reduction (down to 30% from the baseline) of intraocular pressure (IOP) was registered in intramuscular metoprolol rabbits. Subconjunctival metoprolol was associated with a faster and more pronounced decrease in IOP as compared to timolol instillations. In case of local or systemic parenteral administration the hypotensive effect of metoprolol lasts for more than a day.

Genomic Locus Modulating IOP in the BXD RI Mouse Strains

PubMed Central

King, Rebecca; Li, Ying; Wang, Jiaxing; Struebing, Felix L.; Geisert, Eldon E.

2018-01-01

Intraocular pressure (IOP) is the primary risk factor for developing glaucoma, yet little is known about the contribution of genomic background to IOP regulation. The present study leverages an array of systems genetics tools to study genomic factors modulating normal IOP in the mouse. The BXD recombinant inbred (RI) strain set was used to identify genomic loci modulating IOP. We measured the IOP in a total of 506 eyes from 38 different strains. Strain averages were subjected to conventional quantitative trait analysis by means of composite interval mapping. Candidate genes were defined, and immunohistochemistry and quantitative PCR (qPCR) were used for validation. Of the 38 BXD strains examined the mean IOP ranged from a low of 13.2mmHg to a high of 17.1mmHg. The means for each strain were used to calculate a genome wide interval map. One significant quantitative trait locus (QTL) was found on Chr.8 (96 to 103 Mb). Within this 7 Mb region only 4 annotated genes were found: Gm15679, Cdh8, Cdh11 and Gm8730. Only two genes (Cdh8 and Cdh11) were candidates for modulating IOP based on the presence of non-synonymous SNPs. Further examination using SIFT (Sorting Intolerant From Tolerant) analysis revealed that the SNPs in Cdh8 (Cadherin 8) were predicted to not change protein function; while the SNPs in Cdh11 (Cadherin 11) would not be tolerated, affecting protein function. Furthermore, immunohistochemistry demonstrated that CDH11 is expressed in the trabecular meshwork of the mouse. We have examined the genomic regulation of IOP in the BXD RI strain set and found one significant QTL on Chr. 8. Within this QTL, there is one good candidate gene, Cdh11. PMID:29496776

Intraocular pressure in clinically normal dromedary camels (Camelus dromedarius).

PubMed

Marzok, Mohamed A; El-Khodery, Sabry A

2015-02-01

To determine the intraocular pressure (IOP) in healthy dromedary camels (Camelus dromedarius). 24 clinically normal dromedary camels. For each camel, the IOP of both eyes was measured with applanation tonometry. Three measurements with < 5% variance were obtained for each eye on the same day of the week for 3 consecutive weeks. Mean IOP was calculated for each eye on each day for comparison purposes. Mean ± SD IOPs for the right (31.1 ± 2.1 mm Hg) and left (30.8 ± 1.9 mm Hg) eyes of immature camels were significantly higher than those for the right (27.1 ± 1.2 mm Hg) and left (28.2 ± 1.2 mm Hg) eyes of mature camels. Intra-assay and interassay coefficients of variation (CVs) for IOP measurements of the right and left eyes did not differ significantly between immature and mature camels. Interassay CVs of IOP measurements for the right and left eyes ranged from 1.5% to 12.1% and 1.2% to 10.3%, respectively, for immature camels and from 1.2% to 17.2% and 1.7% to 18.8%, respectively, for mature camels. Intra-assay CVs of IOP measurements for the right and left eyes ranged from 1.5% to 10.6% and 1.9% to 9.6%, respectively, for immature camels and from 2.8% to 16.9% and 2.7% to 12.4%, respectively, for mature camels. Age was negatively correlated (r = -0.403) with IOP. Results provided a reference and might aid in the diagnosis of glaucoma and uveitis during complete ophthalmic examinations of dromedary camels.

Corneal hysteresis in patients with glaucoma-like optic discs, ocular hypertension and glaucoma.

PubMed

Murphy, Melissa L; Pokrovskaya, Olya; Galligan, Marie; O'Brien, Colm

2017-01-10

To compare corneal hysteresis (CH) measurements between patients with glaucoma, ocular hypertension (OHT) and glaucoma-like optic discs (GLD)- defined as a cup to disc ratio greater than or equal to 0.6 with normal intraocular pressure (IOP) and visual fields. The secondary aim was to investigate whether corneal resistance factor (CRF) and central corneal thickness (CCT) differ between patient groups. In this cross sectional study a total of 123 patients (one eye each) were recruited from a glaucoma outpatient department to undergo ocular response analyser (ORA) testing and ultrasound pachymetry as well as clinical examination. A One-way Analysis of Covariance (ANCOVA) was conducted to evaluate the mean difference in CH between the three diagnostic groups (glaucoma, OHT and GLD) correcting for potential confounding factors, IOP and age. Analysis was repeated for CRF and CCT. There was a significant difference in mean CH across the three diagnosis groups; F(2, 115) = 96.95; p < 0.001. Mean CH significantly higher for GLD compared to glaucoma (mean difference 1.83, p < 0.001), and significantly higher for OHT compared to glaucoma (mean difference 2.35, p < 0.001). Mean CH was slightly lower in patients with GLD than those with OHT but this difference was not statistically significant. A similar pattern was seen when the analysis was repeated for CRF and CCT. Higher CH in GLD and OHT compared to glaucoma suggests increased viscoelasticity of ocular tissues may have a protective role against glaucoma.

A sample predictive model for intraocular pressure following laser in situ keratomileusis for myopia and an "intraocular pressure constant".

PubMed

Bahadir Kilavuzoglu, Ayse Ebru; Bozkurt, Tahir Kansu; Cosar, Cemile Banu; Sener, Asım Bozkurt

2017-06-24

To describe a sample predictive model for intraocular pressure (IOP) following laser in situ keratomileusis (LASIK) for myopia and an IOP constant. The records of patients that underwent LASIK for myopia and myopic astigmatism via WaveLight Allegretto Wave Eye-Q 400 Hz excimer laser and Hansatome XP microkeratome were retrospectively reviewed. Patients with no systemic or ocular disease other than myopia or myopic astigmatism were included in the study. Preoperative and postoperative month 1 data and intraoperative data were used to build the predictive model for IOP after LASIK. The IOP constant was calculated by subtracting the predicted IOP from preoperative IOP. The paired samples t test, Pearson's correlation analysis, curve estimation analysis, and linear regression analysis were used to evaluate the study data. The study included 425 eyes in 214 patients with a mean age of 32 ± 7.8 years. Mean spherical equivalent of the attempted correction (SE-ac) was -3.7 ± 1.7 diopters. Mean post-LASIK decrease in IOP was 4.6 ± 2.3 mmHg. The difference between preoperative and postoperative IOP was statistically significant (P < 0.001). SE-ac, preoperative IOP, and central corneal thickness had highly significant effects on postoperative IOP, based on linear regression analysis (P < 0.001 and R 2  = 0.043, P < 0.001 and R 2  = 0.370, and P < 0.001 and R 2  = 0.132, respectively). Regression model was created (F = 127.733, P < 0.001), and the adjusted R 2 value was 0.548. Evaluation of IOP after LASIK is important in myopic patients. The present study described a practical formula for predicting the true IOP with the aid of an IOP constant value in myopic eyes following LASIK.

In-vivo corneal pulsation in relation to in-vivo intraocular pressure and corneal biomechanics assessed in-vitro. An animal pilot study.

PubMed

Rogala, Maja M; Danielewska, Monika E; Antończyk, Agnieszka; Kiełbowicz, Zdzisław; Rogowska, Marta E; Kozuń, Marta; Detyna, Jerzy; Iskander, D Robert

2017-09-01

The aim was to ascertain whether the characteristics of the corneal pulse (CP) measured in-vivo in a rabbit eye change after short-term artificial increase of intraocular pressure (IOP) and whether they correlate with corneal biomechanics assessed in-vitro. Eight New Zealand white rabbits were included in this study and were anesthetized. In-vivo experiments included simultaneous measurements of the CP signal, registered with a non-contact method, IOP, intra-arterial blood pressure, and blood pulse (BPL), at the baseline and short-term elevated IOP. Afterwards, thickness of post-mortem corneas was determined and then uniaxial tensile tests were conducted leading to estimates of their Young's modulus (E). At the baseline IOP, backward stepwise regression analyses were performed in which successively the ocular biomechanical, biometric and cardiovascular predictors were separately taken into account. Results of the analysis revealed that the 3rd CP harmonic can be statistically significantly predicted by E and central corneal thickness (Models: R 2  = 0.662, p < 0.005 and R 2  = 0.832, p < 0.001 for the signal amplitude and power, respectively). The 1st CP harmonic can be statistically significantly predicted by the amplitude and power of the 1st BPL harmonic (Models: R 2  = 0.534, p = 0.015 and R 2  = 0.509, p < 0.018, respectively). For elevated IOP, non-parametric analysis indicated significant differences for the power of the 1st CP harmonic (Kruskal-Wallis test; p = 0.031) and for the mean, systolic and diastolic blood pressures (p = 0.025, p = 0.019, p = 0.033, respectively). In conclusion, for the first time, the association between parameters of the CP signal in-vivo and corneal biomechanics in-vitro was confirmed. In particular, spectral analysis revealed that higher amplitude and power of the 3rd CP harmonic indicates higher corneal stiffness, while the 1st CP harmonic correlates positively with the corresponding harmonic of the BPL

Intra-abdominal pressure: an integrative review.

PubMed

Milanesi, Rafaela; Caregnato, Rita Catalina Aquino

2016-01-01

There is a growing request for measuring intra-abdominal pressure in critically ill patients with acute abdominal pain to be clarified. Summarizing the research results on measurement of vesical intra-abdominal pressure and analyzing the level of evidence were the purposes of this integrative literature review, carried out based on the databases LILACS, MEDLINE and PubMed, from 2005 to July 2012. Twenty articles were identified, in that, 12 literature reviews, 4 descriptive and exploratory studies, 2 expert opinions, one prospective cohort study and one was an experience report. The vesical intra-abdominal pressure measurement was considered gold standard. There are variations in the technique however, but some common points were identified: complete supine position, in absence of abdominal contracture, in the end of expiration and expressed in mmHg. Most research results indicate keeping the transducer zeroed at the level of the mid-axillary line at the iliac crest level, and instill 25mL of sterile saline. Strong evidence must be developed. RESUMO Em pacientes críticos com quadros abdominais agudos a esclarecer é crescente a solicitação da aferição da pressão intra-abdominal. Sintetizar resultados de pesquisas sobre a mensuração da pressão intra-abdominal pela via vesical e analisar o nível de evidência foram os objetivos desta revisão integrativa da literatura, realizada nas bases LILACS, MEDLINE e PubMed, no período de 2005 a julho de 2012. Identificaram-se 20 artigos, sendo 12 revisões de literatura, 4 estudos exploratório-descritivos, 2 opiniões de especialistas, 1 estudo de coorte prospectivo e 1 relato de experiência. O método vesical para mensuração da pressão intra-abdominal foi considerado padrão-ouro. Existem variações na técnica, entretanto pontos em comum foram identificados: posição supina completa, na ausência de contratura abdominal, ao final da expiração e expressa em mmHg. A maioria indica posicionar o ponto zero do

Is intra-bladder pressure measurement a reliable indicator for raised intra-abdominal pressure? A prospective comparative study.

PubMed

Al-Abassi, Abdulla Ahmed; Al Saadi, Azan Saleh; Ahmed, Faisal

2018-06-19

Intra-abdominal pressure (IAP) can be measured by several indirect methods; however, the urinary bladder is largely preferred. The aim of this study was to compare intra-bladder pressure (IBP) at different levels of IAPs and assess its reliability as an indirect method for IAP measurement. We compared IBP with IAP in twenty-one patients undergoing laparoscopic cholecystectomy under general anesthesia. Measurements were recorded at increasing levels of insufflation pressures to approximately 22 mmHg. Pearson's correlation coefficient was calculated to establish the relationship between the two pressure measurements and Bland-Altman analysis was used to assess the limits of agreement between the two methods of measurements. The urinary bladder pressures reflected well the pressures in the abdominal cavity. Pearson correlation coefficient showed a good correlation between the two measurement techniques (r = 0.966, p < 0.0001) and Bland-Altman analysis indicated that the 95% limits of agreement between the two methods ranged from - 2.83 to 2.64. This range is accepted both clinically and according to the recommendations of the World Society of Abdominal Compartment Syndrome (WSACS). Our study showed that IBP measurement is a simple, minimally invasive method that may reliably estimates IAP in patients placed in supine position. Measurements for pressures higher than 12 mmHg may be less reliable. When applied clinically, this should alert the clinician to take safety measures to avoid abdominal compartment syndrome (ACS).

Long-term effect of latanoprost/timolol fixed combination in patients with glaucoma or ocular hypertension: A prospective, observational, noninterventional study

PubMed Central

2010-01-01

Background Prospective, observational studies that enroll large numbers of patients with few exclusion criteria may better reflect actual ongoing clinical experience than randomized clinical trials. Our purpose was to obtain efficacy and safety information from a cohort of subjects exposed to latanoprost/timolol fixed combination (FC) for ≥18 months using a prospective, observational design. Methods In all, 577 office-based ophthalmologists in Germany switched 2339 patients with glaucoma or ocular hypertension to latanoprost/timolol FC for medical reasons. Follow-up visits were scheduled for every 6 months over 24 months; physicians followed usual care routines. Intraocular pressure (IOP), visual field status, optic nerve head findings, and adverse events were recorded. Efficacy parameters were evaluated for the per protocol (PP) population; the safety population included subjects receiving ≥1 drop of FC. Physicians rated efficacy, tolerability, and subject compliance at month 24. Results Of the 2339 subjects switched to latanoprost/timolol FC (safety population), the primary reasons for switching were inadequate IOP reduction (78.2%) and desire to simplify treatment with once-daily dosing (29.4%; multiple reasons possible). In all, 1317 (56.3%) subjects completed the study, and 1028 (44.0%) were included in the PP population. Most discontinuations were due to loss to follow-up. Change in mean IOP from baseline to month 6 was -4.0 ± 4.31 mmHg, a reduction that was maintained throughout (P < 0.05 for change at all time points). By investigator assessments, optic disc parameters and visual field were stable over 24 months, and there was no relationship between IOP reduction over 24 months and development of a visual field defect. More than 90% of physicians rated latanoprost/timolol FC as "very good" or "good" for efficacy (PP population), tolerability, and compliance. The FC was safe and well tolerated. No change in iris color was reported by most subjects (83

A randomized, controlled phase I/II study to evaluate the safety and efficacy of MGV354 for ocular hypertension or glaucoma.

PubMed

Stacy, Rebecca; Huttner, Kenneth; Watts, Jen; Peace, James; Wirta, David; Walters, Tom; Sall, Kenneth; Seaman, John; Ni, Xiao; Prasanna, Ganesh; Mogi, Muneto; Adams, Christopher; Yan, Jing-He; Wald, Michael; He, Yunsheng; Newton, Ronald; Kolega, Randall; Grosskreutz, Cynthia

2018-05-23

To assess the clinical safety, tolerability, and efficacy of topically administered MGV354, a soluble guanylate cyclase (sGC) activator, in patients with ocular hypertension (OH) or glaucoma DESIGN: Double-masked, randomized, and vehicle-controlled study METHODS: Parts 1 and 2 evaluated safety and tolerability to identify the maximum tolerated dose (MTD) of once daily MGV354 in 32 healthy volunteers (Part 1) and 16 patients with OH or glaucoma (Part 2) at a single clinical site. Part 3 was a multi-site trial that evaluated IOP-lowering efficacy of the MTD administered nightly for one week in 50 patients with minimum IOP of 24mm Hg at 8 AM, with a main outcome measure of mean diurnal IOP at Day 8 compared to baseline (ClinicalTrials.gov NCT02743780). There was no difference in favor of MGV354 for IOP lowering; change from Baseline to Day 8 in mean diurnal IOP was -0.6 mmHg for MGV354-treated patients and -1.1 mmHg for Vehicle-treated patients in Part 3, with a confidence interval of -0.7 to 1.7. The most common adverse events reported after MGV354 administration were conjunctival and ocular hyperemia. Overall, MGV354 0.1% demonstrated no statistically significant effect compared to Vehicle in lowering IOP based upon the study's main outcome measure. MGV354 produced ocular hyperemia consistent with its pharmacology. Copyright © 2018 Elsevier Inc. All rights reserved.

Double-masked, randomized, dose-response study of AR-13324 versus latanoprost in patients with elevated intraocular pressure.

PubMed

Bacharach, Jason; Dubiner, Harvey B; Levy, Brian; Kopczynski, Casey C; Novack, Gary D

2015-02-01

AR-13324 is a small-molecule inhibitor of Rho kinase and a norepinephrine transporter. The objective of this 28-day study was to evaluate the ocular hypotensive efficacy and safety of AR-13324 ophthalmic solution compared with a positive control, latanoprost ophthalmic solution, in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT). Double-masked, randomized study in 22 private practice ophthalmology clinics. Participants were required to be adults with a diagnosis of OAG or OHT with unmedicated intraocular pressure (IOP) in the range of 22 to 36 mmHg. Patients were randomized to receive AR-13324 ophthalmic solution 0.01%, daily (pm), AR-13324 ophthalmic solution 0.02% daily (pm), or latanoprost 0.005% daily (pm) for 28 days. The primary efficacy endpoint was the mean diurnal IOP across subjects within the treatment group at day 28. Randomized and treated were 224 patients, 213 (95.1%) of whom completed the study. On day 28, mean diurnal IOP was 20.1, 20.0, and 18.7 mmHg in the AR-13324 0.01%, 0.02%, and latanoprost groups, respectively, representing a decrease from unmedicated baseline of 5.5, 5.7, and 6.8 mmHg (P<0.001). The 5.7-mmHg reduction in IOP by AR-13324 0.02% did not meet the criterion for noninferiority to latanoprost. The most frequently reported adverse event was conjunctival/ocular hyperemia, with a combined incidence of 52%, 57%, and 16%, respectively. On day 28 at 08:00 hours, the incidence of mild to moderate hyperemia by biomicroscopy was 18%, 24%, and 11%, respectively. AR-13324 0.02% was less effective than latanoprost by approximately 1 mmHg in patients with unmedicated IOPs of 22 to 35 mmHg. The major safety finding was ocular hyperemia, which was more common for both concentrations of AR-13324 than for latanoprost. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Ocular surface changes in glaucomatous patients treated with and without preservatives beta-blockers.

PubMed

Iester, Michele; Telani, Serena; Frezzotti, Paolo; Motolese, Ilaria; Figus, Michele; Fogagnolo, Paolo; Perdicchi, Andrea

2014-08-01

To determine whether there were ocular surface changes in glaucomatous patients treated with preservatives beta-blockers who switched to preservative-free beta-blockers. This was a prospective, longitudinal, open-labeled study. One hundred thirty-two patients with primary open angle glaucoma treated with a preserved beta-blocker were enrolled. All the patients underwent perimetric and gonioscopic examination, complete ophthalmologic examination, intraocular pressure (IOP) measurements, evaluation of ocular surface, Schirmer's test, blood pressure and heart rate at baseline and 1-3 months after changing the medical treatment to a preservative-free timolol 0.1% (Timogel 0.1; Thea). At baseline, after 1 month and at the end of the study (3 months), all patients underwent a questionnaire on the visual quality and symptoms and on the quality of life (QoL). Data were analyzed by t-test when the distribution of the data was normal, by Mann-Whitney when the distribution was not normal. No significant difference was found for IOP before switching from preserved beta-blockers to preservative-free ones. No significant difference was found in blood pressure and heart rate. However, a statistically significant difference was found for abnormal fluorescein staining of the cornea and conjunctiva, eyelid erythema, conjunctival hyperemia, and follicular hyperplasia. A significant difference was found for break-up time (from 9.38±4.7 s at baseline to 10.64±4.7 s after 3 months) and Schirmer's test (from 12.9±5.96 mm at baseline to 14.2±5.87 mm after 3 months). The questionnaire showed that the patient improved the dryness and foreign body sensation. In glaucomatous patients, preservative-free 0.1 timolol treatment improved their QoL. Similar dry eye signs or symptoms improved after 3 months of treatment reducing dryness, hyperemia, follicular hyperplasia, and foreign body sensation.

Change in intraocular pressure during scleral depression.

PubMed

Trevino, Richard; Stewart, Brandi

2015-01-01

Manometric studies have found that intraocular pressure (IOP) rises 116-350 mmHg during scleral depression in surgical settings. No information is available regarding the effect of scleral depression on IOP in routine clinical settings. The aim of this study is to quantify the change in IOP that occurs when scleral depression is performed on normal eyes in a routine clinical setting. A total of 28 eyes from 28 normal subjects were included. Tono-Pen tonometry was performed while scleral depression was performed in each of the two quadrants: superotemporal (ST) and inferonasal (IN). A post-procedure IOP measurement was obtained following each scleral depression examination. Both ST and IN quadrants were tested on all eyes, with the quadrant tested first chosen at random (15 ST, 13 IN). The mean IOP during scleral depression was 65.3 mmHg ST and 47.8 mmHg IN, with a maximum recorded IOP of 88 mmHg. The mean change in IOP for the ST quadrant was 51.9 ± 17.3 mmHg and 46.4 ± 16.0 mmHg for the right and left eyes, respectively. The mean change in IOP for the IN quadrant was 45.3 ± 22.7 mmHg and 16.8 ± 15.8 mmHg for the right and left eyes, respectively. Scleral depression as performed in a routine office setting produces wide fluctuations in IOP and may impair ocular perfusion. Additional studies are needed to determine the long-term consequences of routine scleral depression. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Comparison of preservative-free latanoprost and preservative-free bimatoprost in a multicenter, randomized, investigator-masked cross-over clinical trial, the SPORT trial.

PubMed

Stalmans, Ingeborg; Oddone, Francesco; Cordeiro, Maria Francesca; Hommer, Anton; Montesano, Giovanni; Ribeiro, Luisa; Sunaric-Mégevand, Gordana; Rossetti, Luca

2016-06-01

The aim of this study was to investigate the efficacy and safety of Bimatoprost Unit Dose Preservative Free (BUDPF) and Latanoprost Unit Dose Preservative Free (LUDPF). A prospective, randomized, investigator-masked, cross-over comparison was used. Inclusion criteria were ocular hypertension (OHT) or open-angle glaucoma (OAG) with a maximum intraocular pressure (IOP) of 21 mmHg on a preserved prostaglandin monotherapy. After 6 weeks washout, patients were randomized to BUDPF or LUDPF for 3 months and then switched to the other treatment for 3 months. IOP curves were performed at baseline and after each treatment period. Statistical analysis was performed in a R programming environment. Linear mixed modeling was used to account for repeated measures on the same subject and clustering of observations from the same center. Safety outcomes included visual acuity, adverse events, slit-lamp biomicroscopy, ocular tolerability, and optic nerve assessment. Analysis at 6 months (primary outcome) showed a 1.6 ± 0.5-mmHg difference in IOP values between LUDPF and BUDPF (p < 0.01). A mean intra-subject IOP difference of 0.9 ± 0.2 mmHg (LUDPF - BUDPF) was observed (p < 0.01).. Significant differences in IOP were observed for both drugs at 3 and at 6 months compared to baseline: -4,0 ± 0.5 mmHg for both BUDPF and LUDPF at 3 months (p < 0.01 for both drugs; p = 0.32 between the two drugs); -5.2 ± 0.5 and -3.4 ± 0.5 mmHg for BUDPF and LUDPF, respectively (both p < 0.01), at 6 months. Both drugs were tolerated well, the only statistically significant difference being lower hyperemia scores for LUDPF (albeit low for both drugs). This study demonstrates a superior efficacy of BUDPF over LUDPF in lowering IOP. The results are consistent both in the parallel comparison between the two treatment groups at 6 months as well as in the intra-subject pressure comparison.

Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes

PubMed Central

Erb, Carl; Carceller Guillamet, Amadeu; Fea, Antonio M; Voskanyan, Lilit; Giamporcaro, Jane Ellen; Hornbeak, Dana M

2018-01-01

Purpose Evaluate long-term outcomes after one, two, or three trabecular micro-bypass stents implanted in a standalone procedure in eyes with open-angle glaucoma taking ocular hypotensive medication. Patients and methods Prospective randomized ongoing study of 119 subjects (109 with 42-month follow-up) with open-angle glaucoma, preoperative intraocular pressure (IOP) 18–30 mmHg on one to three glaucoma medications, and unmedicated (post-washout) IOP 22–38 mmHg. Subjects were randomized to receive one (n=38), two (n=41), or three (n=40) iStent trabecular micro-bypass stents in a standalone procedure. Postoperatively, IOP was measured with medication and annually following washout. Data included IOP, medications, gonioscopy, pachymetry, visual field, visual acuity, adverse events, and slit-lamp and fundus examinations. Results Preoperative mean medicated IOP was 19.8±1.3 mmHg on 1.71 medications in one-stent eyes, 20.1±1.6 mmHg on 1.76 medications in two-stent eyes, and 20.4±1.8 mmHg on 1.53 medications in three-stent eyes. Post-washout IOP prior to stent implantation was 25.0±1.2, 25.0±1.7, and 25.1±1.9 mmHg in the three groups, respectively. Postoperatively, Month 42 medicated IOP was 15.0±2.8, 15.7±1.0 and 14.8±1.3 mmHg in the three groups, and post-washout IOP (Months 36–37) was 17.4±0.9, 15.8±1.1 and 14.2±1.5 mmHg, respectively. IOP reduction ≥20% without medication was achieved in 89%, 90%, and 92% of one-, two-, and three-stent eyes, respectively, at Month 12; and in 61%, 91%, and 91% of eyes, respectively, at Month 42. The need for additional medication remained consistent at Months 12 and 42 in multi-stent eyes (four two-stent eyes and three three-stent eyes at both time points), whereas it increased in single-stent eyes (four eyes at Month 12 versus 18 eyes at Month 42). Safety parameters were favorable in all groups. Conclusion The standalone implantation of either single or multiple iStent® device(s) produced safe, clinically

Clinical investigation of the effect of topical anesthesia on intraocular pressure

PubMed Central

Almubrad, Turki M; Ogbuehi, Kelechi C

2007-01-01

Background/Aims: Contact tonometry is generally considered more accurate than non-contact tonometry in the assessment of intraocular pressure (IOP). This study was designed to investigate the effect of ocular anesthesia, a pre-requisite for contact tonometry, on the IOP in a sample of visually normal subjects. Method: In a random sample of 120 young visually normal subjects (divided equally among three groups), the Topcon CT80 non-contact tonometer was used to measure IOP before, at the second minute and at the fifth minute following instillation of one drop of one of three eyedrops – carboxymethylcellulose sodium 0.5% (control), oxybuprocaine hydrochloride 0.4% and proparacaine hydrochloride 0.5%. Results: The IOP measured before instilling the ophthalmic drops did not vary significantly among the three groups of subjects (p > 0.05). In the control group, the average IOP of 15.1 ± 2.6 mmHg did not vary significantly (p > 0.05) 2 minutes and 5 minutes following instillation of one drop of Carboxymethylcellulose sodium. There were statistically significant reductions of IOP 2 minutes (p < 0.01) and 5 minutes (p < 0.001) after the instillation of one drop of oxybuprocaine hydrochloride. One drop of proparacaine hydrochloride caused significant reductions in the average IOP after 2 minutes (p < 0.001) and after 5 minutes (p < 0.001). Conclusions: One drop of topical proparacaine or oxybuprocaine may cause a small but a statistically significant reduction in IOP which could lead to lower IOP readings. PMID:19668485

Clinical investigation of the effect of topical anesthesia on intraocular pressure.

PubMed

Almubrad, Turki M; Ogbuehi, Kelechi C

2007-09-01

Contact tonometry is generally considered more accurate than non-contact tonometry in the assessment of intraocular pressure (IOP). This study was designed to investigate the effect of ocular anesthesia, a pre-requisite for contact tonometry, on the IOP in a sample of visually normal subjects. In a random sample of 120 young visually normal subjects (divided equally among three groups), the Topcon CT80 non-contact tonometer was used to measure IOP before, at the second minute and at the fifth minute following instillation of one drop of one of three eyedrops - carboxymethylcellulose sodium 0.5% (control), oxybuprocaine hydrochloride 0.4% and proparacaine hydrochloride 0.5%. The IOP measured before instilling the ophthalmic drops did not vary significantly among the three groups of subjects (p > 0.05). In the control group, the average IOP of 15.1 +/- 2.6 mmHg did not vary significantly (p > 0.05) 2 minutes and 5 minutes following instillation of one drop of Carboxymethylcellulose sodium. There were statistically significant reductions of IOP 2 minutes (p < 0.01) and 5 minutes (p < 0.001) after the instillation of one drop of oxybuprocaine hydrochloride. One drop of proparacaine hydrochloride caused significant reductions in the average IOP after 2 minutes (p < 0.001) and after 5 minutes (p < 0.001). One drop of topical proparacaine or oxybuprocaine may cause a small but a statistically significant reduction in IOP which could lead to lower IOP readings.

Plasma rich in growth factors eye drops to treat secondary ocular surface disorders in patients with glaucoma

PubMed Central

Sánchez-Avila, Ronald M; Merayo-Lloves, Jesus; Fernández, Maria Laura; Rodríguez-Gutiérrez, Luis Alberto; Rodríguez-Calvo, Pedro Pablo; Fernández-Vega Cueto, Andres; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

2018-01-01

Purpose To evaluate the efficacy and safety of plasma rich in growth factors (PRGF) eye drops in patients with glaucoma with secondary ocular surface disorders (OSDs) due to surgeries and topical hypotensive drugs use. Materials and methods A retrospective case-series study design was used including six patients (eight eyes) diagnosed with glaucoma who received surgical (nonpenetrating deep sclerectomy and/or trabeculectomy) and medical treatments (hypotensive eye drops) to control intraocular pressure (IOP) and who developed secondary OSDs, unresponsive to conventional treatments. Patients were treated with PRGF eye drops (four times a day). Outcome measures were ocular surface disease index (OSDI), best-corrected visual acuity (BCVA, in logarithm of the minimum angle of resolution), visual analog scale (VAS), frequency and severity of symptoms, and IOP. The safety of the treatment was also evaluated. Results Six patients (seven eyes with open-angle glaucoma and one eye with uveitic glaucoma) treated with PRGF eye drops were evaluated. Mean age was 71 years (SD=7.2, range 58–79 years). Five were female and one was male. The mean treatment time was 21.8 weeks (SD=9.0, range 12–36 weeks). The mean time to reach closure of the corneal ulcer was 14.5 (SD=5.5) weeks. A statistical significant reduction in OSDI scale (50.6%), VAS frequency (53.1%), VAS severity (42.0%), and a 41.8% improvement in BCVA were observed (p<0.05). IOP also decreased by 16.6% (p=0.010). Only one of the six patients reported itching in both eyes as an adverse event (AE); however, the patient continued with the PRGF eye drops until the end of therapy; the remaining patients did not report any AEs during the follow-up period. Conclusions In patients with glaucoma and secondary OSDs refractive to conventional treatments, the treatment with PRGF eye drops could be considered a possible therapeutic option, because it demonstrates an improvement in the signs and symptoms of the ocular surface, as

Plasma rich in growth factors eye drops to treat secondary ocular surface disorders in patients with glaucoma.

PubMed

Sánchez-Avila, Ronald M; Merayo-Lloves, Jesus; Fernández, Maria Laura; Rodríguez-Gutiérrez, Luis Alberto; Rodríguez-Calvo, Pedro Pablo; Fernández-Vega Cueto, Andres; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

2018-01-01

To evaluate the efficacy and safety of plasma rich in growth factors (PRGF) eye drops in patients with glaucoma with secondary ocular surface disorders (OSDs) due to surgeries and topical hypotensive drugs use. A retrospective case-series study design was used including six patients (eight eyes) diagnosed with glaucoma who received surgical (nonpenetrating deep sclerectomy and/or trabeculectomy) and medical treatments (hypotensive eye drops) to control intraocular pressure (IOP) and who developed secondary OSDs, unresponsive to conventional treatments. Patients were treated with PRGF eye drops (four times a day). Outcome measures were ocular surface disease index (OSDI), best-corrected visual acuity (BCVA, in logarithm of the minimum angle of resolution), visual analog scale (VAS), frequency and severity of symptoms, and IOP. The safety of the treatment was also evaluated. Six patients (seven eyes with open-angle glaucoma and one eye with uveitic glaucoma) treated with PRGF eye drops were evaluated. Mean age was 71 years (SD=7.2, range 58-79 years). Five were female and one was male. The mean treatment time was 21.8 weeks (SD=9.0, range 12-36 weeks). The mean time to reach closure of the corneal ulcer was 14.5 (SD=5.5) weeks. A statistical significant reduction in OSDI scale (50.6%), VAS frequency (53.1%), VAS severity (42.0%), and a 41.8% improvement in BCVA were observed ( p <0.05). IOP also decreased by 16.6% ( p =0.010). Only one of the six patients reported itching in both eyes as an adverse event (AE); however, the patient continued with the PRGF eye drops until the end of therapy; the remaining patients did not report any AEs during the follow-up period. In patients with glaucoma and secondary OSDs refractive to conventional treatments, the treatment with PRGF eye drops could be considered a possible therapeutic option, because it demonstrates an improvement in the signs and symptoms of the ocular surface, as well as a better control of the IOP. This is an

Latanoprostene Bunod 0.024% in Subjects With Open-angle Glaucoma or Ocular Hypertension: Pooled Phase 3 Study Findings.

PubMed

Weinreb, Robert N; Liebmann, Jeffrey M; Martin, Keith R; Kaufman, Paul L; Vittitow, Jason L

2018-01-01

To compare the diurnal intraocular pressure (IOP)-lowering effect of latanoprostene bunod (LBN) 0.024% with timolol maleate 0.5% in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT). Pooled analysis of two phase 3, randomized, multicenter, double-masked, parallel-group, noninferiority trials (APOLLO and LUNAR), each with open-label safety extension phases. Adults with OAG or OHT were randomized 2:1 to double-masked treatment with LBN once daily (qd) or timolol twice daily (bid) for 3 months followed by open-label LBN treatment for 3 (LUNAR) or 9 (APOLLO) months. IOP was measured at 8 AM, 12 PM, and 4 PM at week 2, week 6, and months 3, 6, 9, and 12. Of the 840 subjects randomized, 774 (LBN, n=523; timolol crossover to LBN, n=251) completed the efficacy phase, and 738 completed the safety extension phase. Mean IOP was significantly lower with LBN versus timolol at all 9 evaluation timepoints during the efficacy phase (P<0.001). A significantly greater proportion of LBN-treated subjects attained a mean IOP ≤18 mm Hg and IOP reduction ≥25% from baseline versus timolol-treated subjects (P<0.001). The IOP reduction with LBN was sustained through the safety phase; subjects crossed over from timolol to LBN experienced additional significant IOP lowering (P≤0.009). Both treatments were well tolerated, and there were no safety concerns with long-term LBN treatment. In this pooled analysis of subjects with OAG and OHT, LBN 0.024% qd provided greater IOP-lowering compared with timolol 0.5% bid and maintained lowered IOP through 12 months. LBN demonstrated a safety profile comparable to that of prostaglandin analogs.

Ocular promoting activity of grape polyphenols-A review.

PubMed

Natarajan, Sithranga Boopathy; Hwang, Jin-Woo; Kim, Yon-Suk; Kim, Eun-Kyung; Park, Pyo-Jam

2017-03-01

The eye is a sensitive organ with complex optical system involves in the perception of light. Although it has several protective mechanisms by itself, various physiological and metabolic disorders are detrimental to the proper functioning of the visual system. Grape juice has long been used worldwide for its potent medicinal values including ocular promotion. Bioactivities of grape products are highly attributed to the presence of health promoting phytochemicals in them. Some phytochemicals present in the grape juice have been involved in the maintenance of intra-ocular pressure, regulation of glucose metabolisms and suppression of pro-inflammatory cytokines in the system. Particularly, the grape derived phytochemicals involve in minimizing various eye defects such as macular degradation, uvea, cataract formation, red eye, diabetic retinopathy and so on. However, only limited number of studies has been conducted so far focusing the ocular promoting activity of grape polyphenols. In this review, we discuss the role of grape polyphenols in ocular promotion relating their anti-oxidant, anti-microbial, anti-aging, anti-hypertensive and anti-inflammatory properties. Copyright © 2016. Published by Elsevier B.V.

Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system

NASA Astrophysics Data System (ADS)

Hirtl, Rene; Schmid, Gernot

2013-09-01

A modern wireless intra-ocular pressure monitoring system, based on 13.56 MHz inductively coupled data transmission, was dosimetrically analyzed with respect to the specific absorption rate (SAR) induced inside the head and the eye due to the electromagnetic field exposure caused by the reader antenna of the transmission system. The analysis was based on numerical finite difference time domain computations using a high resolution anatomical eye model integrated in a modern commercially available anatomical model of a male head. Three different reader antenna configurations, a 7-turn elliptic (30 mm × 50 mm) antenna at 12 mm distance from the eye, a flexible circular antenna (60 mm diameter, 8 turns on 2 mm substrate) directly attached to the skin, and a circular 7-turn antenna (30 mm diameter at 12 mm distance to the eye) were analyzed, respectively. Possible influences of the eye-lid status (closed or opened) and the transponder antenna contained in a contact lens directly attached to the eye were taken into account. The results clearly demonstrated that for typical reader antenna currents required for proper data transmission, the SAR values remain far below the limits for localized exposure of the head, as defined by the International Commission for Non-Ionizing Radiation Protection. Particularly the induced SAR inside the eye was found to be substantially (orders of magnitudes for typical reader antenna currents in the order of 1 A turn) below values which have been reported to be critical with respect to thermally induced adverse health effects in eye tissues.

Haemodynamic stability during general anaesthesia for intra-ocular surgery: the effect of topical oxybuprocaine.

PubMed

Lytle, J; Thomas, N F

1992-07-01

Local anaesthesia is frequently used in combination with light general anaesthesia to reduce the reflex responses to surgical stimulation. This combination has not previously been evaluated for intra-ocular surgery. During cataract extraction under general anaesthesia, the effect of topical anaesthesia with oxybuprocaine 0.4% on the pressor response was compared with normal saline in a control group. The simple technique of instilling local anaesthetic drops into the conjunctival sac blocked the pain pathway sufficiently to prevent the pressor response to surgical stimulation (p less than 0.001). Higher inspired concentrations of enflurane were required in the control group to achieve and maintain haemodynamic stability (p less than 0.001).

Prospective Observational Post-marketing Study of Tafluprost 0.0015%/Timolol 0.5% Combination Ophthalmic Solution for Glaucoma and Ocular Hypertension: Short-Term Efficacy and Safety.

PubMed

Takagi, Yasutaka; Osaki, Hirotaka; Yamashita, Tomohiro; Kai, Yasuhiko

2016-12-01

The intraocular pressure (IOP)-lowering effect and safety of tafluprost 0.0015%/timolol maleate 0.5% combination ophthalmic solution (Taf-TFC) were investigated in a real-world clinical setting. A prospective up to 2-year (more than 1 year) observational study has been initiated to collect data on the IOP, conjunctival hyperemia score, corneal staining score, and adverse events suffered by patients with glaucoma or ocular hypertension treated at 3 months, and up to 2 years (more than 1 year) after initiating treatment with Taf-TFC. The 3-month findings are reported here. Among 439 patients enrolled at 100 institutions in Japan, most had normal tension glaucoma (45.3%) or primary open angle glaucoma (36.0%). Adverse drug reaction (ADR) occurred in 5.01%. The important ADRs were conjunctival hyperemia (five patients), blepharitis (four patients), and punctate keratitis (two patients). Serious adverse reactions occurred in two patients (three events). In 410 patients with data both before and after treatment, baseline mean IOP was 17.5 ± 5.0 mmHg, and it was significantly decreased after 1, 2, and 3 months (all P < 0.05, paired-t test). IOP was significantly reduced in patients switched to Taf-TFC from either prostaglandin or β-blocker monotherapy. IOP also decreased significantly in patients switched from a prostaglandin/timolol fixed combination, but not in patients switched from concomitant use of a prostaglandin analog and a β-blocker. The use of Taf-TFC did not worsen the adherence in most patients. Taf-TFC significantly reduced the IOP in patients with glaucoma or ocular hypertension treated in daily clinical practice with controllable or recoverable ADRs in short period. Taf-TFC was effective regardless of treatment patterns, and particularly, Taf-TFC significantly reduced IOP in cases in which requiring the second line therapy as insufficient of monotherapy. Santen Pharmaceutical Co., Ltd., Osaka, Japan.

Comparison of Ocular Outcomes in Two 14-Day Bed Rest Studies

NASA Technical Reports Server (NTRS)

Cromwell, R. L.; Zanello, S. B.; Yarbough, P. O.; Taibbi, G.; Vizzeri, G.

2011-01-01

Reports of astronauts visual changes raised concern about ocular health during long-duration spaceflight. Some of these findings included hyperopic shifts, choroidal folds, optic disc edema, retinal nerve fiber layer (RNFL) thickening, and cotton wool spots. While the etiology remains unknown, hypotheses speculate that hypertension in the brain caused by cephalad fluid shifts during spaceflight is a possible mechanism for these ocular changes. Head-down tilt (HDT) bed rest is a spaceflight analog that induces cephalad fluid shifts. In addition, previous studies of the HDT position demonstrated body fluid shifts associated with changes in intraocular pressure (IOP). For these reasons, vision monitoring of HDT bed rest subjects was implemented for NASA bed rest studies. Subjects selected for these studies were healthy adults (14 males and 5 females). Average age was 37.5 plus or minus 9.1 years, weight was 77.4 plus or minus 11.3 Kg, and height was 173.4 plus or minus 7.2 14 cm. Controlled conditions followed for all NASA bed rest studies were implemented. These conditions included factors such as eating a standardized diet, maintaining a strict sleep wake cycle, and remaining in bed for 24 hours each day. In one study, subjects maintained a horizontal (0 degree) position while in bed and were exercised six days per week with an integrated resistance and aerobic training (iRAT) program. In the other study, subjects were placed at 6 degrees HDT while in bed and did not engage in exercise. All subjects underwent pre- and post bed rest vision testing. While the battery of vision tests for each study was not identical, measures common to both studies will be presented. These measures included IOP and measures that provided an indication of optic disc swelling as derived from optical coherence tomography (OCT) testing: average retinal nerve fiber layer (RNFL) thickness (millimeters), disc area (square millimeters), rim area (square millimters), and average cup to disc (C

Ocular biomechanical measurements on post-keratoplasty corneas using a Scheimpflug-based noncontact device

PubMed Central

Modis, Laszlo; Hassan, Ziad; Szalai, Eszter; Flaskó, Zsuzsanna; Berta, Andras; Nemeth, Gabor

2016-01-01

AIM To analyse ocular biomechanical properties, central corneal thickness (CCT) and intraocular pressure (IOP) in post-keratoplasty eyes, as compared to normal subjects, with a new Scheimpflug-based technology. Moreover, biomechanical data were correlated with the size and age of the donor and recipient corneas. METHODS Measurements were conducted on 46 eyes of 46 healthy patients without any corneal pathology (age: 53.83±20.8y) and 30 eyes of 28 patients after penetrating keratoplasty (age: 49.43±21.34y). Ten biomechanical parameters, the CCT and IOP were recorded by corneal visualization scheimpflug technology (CorVis ST) using high-speed Scheimpflug imaging. Keratometry values were also recorded using Pentacam HR system. Scheimpflug measurements were performed after 43.41±40.17mo (range: 11-128mo) after the keratoplasty and after 7.64±2.34mo (range: 5-14mo) of suture removal. RESULTS Regarding the device-specific biomechanical parameters, the highest concavity time and radius values showed a significant decrease between these two groups (P=0.01 and P<0.001). None of other biomechanical parameters disclosed a significant difference. The CCT showed a significant difference between post-keratoplasty eyes as compared to normal subjects (P=0.003) using the CorVis ST device. The IOP was within the normal range in both groups (P=0.84). There were no significant relationships between the keratometric data, the size of the donor and recipient, age of the donor and recipient and biomechanical properties obtained by CorVis ST. CONCLUSION The ocular biomechanics remain stable after penetrating keratoplasty according to the CorVis ST measurements. Only two from the ten device-specific parameters have importance in the follow-up period after penetrating keratoplasty. PMID:26949641

Multicenter, Randomized, Controlled Study Comparing Tafluprost/Timolol Fixed Combination with Latanoprost/Timolol Fixed Combination in Primary Open-Angle Glaucoma and Ocular Hypertension.

PubMed

Suzuki, Katsuyoshi; Otsuka, Naomi; Hizaki, Hiroko; Hashimoto, Masayo; Kuwayama, Yasuaki

2018-06-05

This was the first exploratory randomized controlled study to compare the efficacy and safety of a preserved tafluprost/timolol fixed combination (TAF/TIM) with a preserved latanoprost/timolol fixed combination (LAT/TIM). This prospective, randomized, open-label study was conducted in Japanese patients with primary open-angle glaucoma, including normal-tension glaucoma or ocular hypertension. Following a 4-week LAT/TIM run-in period, eligible patients entered a 12-week treatment period, during which they received either LAT/TIM or TAF/TIM. The efficacy endpoint was the change in intraocular pressure (IOP) from baseline to week 12 and the safety endpoints included the changes from baseline to week 12 in superficial punctate keratopathy (SPK) score, tear breakup time (TBUT), and hyperemia score, as well as adverse events (AEs). At week 6, ocular symptoms were evaluated using a questionnaire. In total, 131 patients provided informed consent. Of these, 115 completed the run-in period and were assigned to receive TAF/TIM (n = 60) or LAT/TIM (n = 55). At week 12, there were no significant differences between the TAF/TIM and LAT/TIM groups in the change from baseline in trough IOP and IOP at 4-6 h after instillation. There were no significant differences between the two groups in the change from baseline to week 12 in SPK score, TBUT, and hyperemia score. However, only in the TAF/TIM group, the total SPK score and the inferior cornea SPK score were significantly lower at week 12 compared with baseline. Eye irritation and eye pain were significantly decreased in the TAF/TIM group compared with the LAT/TIM group. Two treatment-related AEs were reported in the TAF/TIM group (3.3%) and none in the LAT/TIM group, while no serious AEs were reported in either group. TAF/TIM is as effective as LAT/TIM in terms of IOP-reducing effect, with fewer ocular symptoms. TAF/TIM was associated with a significant improvement in SPK scores. UMIN Clinical Trials Registry Identifier

Muscular Strength Is Associated with Higher Intraocular Pressure in Physically Active Males.

PubMed

Vera, Jesús; Jiménez, Raimundo; García-Ramos, Amador; Cárdenas, David

2018-02-01

The positive association between intraocular pressure (IOP) and relative maximum force may have relevance for exercise recommendations when IOP is a concern. The relationship between exercise and IOP has been approached in several studies. However, the influence of muscle function on IOP remains underexplored. This study aimed to determine the relationship between the maximal mechanical capabilities of muscles to generate force, velocity, and power with IOP. Sixty-five physically active males participated in this cross-sectional study. Baseline IOP measures were obtained by rebound tonometry, and participants performed an incremental loading test in the ballistic bench press. Baseline IOP showed a strong positive correlation with relative maximum force (r65 = 0.85, P < .001) relative maximum power (r65 = 0.85, P < .001), and relative one-repetition maximum (r65 = 0.91, P < .001). Also, a moderate positive association was obtained between baseline IOP and maximum force (r65 = 0.74, P < .001), maximum power (r65 = 0.72, P < .001), and maximum dynamic strength (r65 = 0.80, P < .001). No significant correlations between IOP and maximal velocity were obtained (all P > .05). There is a positive association between greater upper-body power and strength with higher baseline IOP, which might have important implications in the management of ocular health and especially in individuals constantly involved in resistance training programs (e.g., military personnel, weightlifters). The possible protective effect of high fitness level on the acute IOP response to strength exercise needs to be addressed in future studies.

Risk calculation variability over time in ocular hypertensive subjects.

PubMed

Song, Christian; De Moraes, Carlos Gustavo; Forchheimer, Ilana; Prata, Tiago S; Ritch, Robert; Liebmann, Jeffrey M

2014-01-01

To investigate the longitudinal variability of glaucoma risk calculation in ocular hypertensive (OHT) subjects. We reviewed the charts of untreated OHT patients followed in a glaucoma referral practice for a minimum of 60 months. Clinical variables collected at baseline and during follow-up included age, central corneal thickness (CCT), intraocular pressure (IOP), vertical cup-to-disc ratio (VCDR), and visual field pattern standard deviation (VFPSD). These were used to calculate the 5-year risk of conversion to primary open-angle glaucoma (POAG) at each follow-up visit using the Ocular Hypertension Treatment Study and European Glaucoma Prevention Study calculator (http://ohts.wustl.edu/risk/calculator.html). We also calculated the risk of POAG conversion based on the fluctuation of measured variables over time assuming the worst case scenarios (final age, highest PSD, lowest CCT, highest IOP, and highest VCDR) and best case scenarios (baseline age, lowest PSD, highest CCT, lowest IOP, and lowest VCDR) for each patient. Risk probabilities (%) were plotted against follow-up time to generate slopes of risk change over time. We included 27 untreated OHT patients (54 eyes) followed for a mean of 98.3±18.5 months. Seven individuals (25.9%) converted to POAG during follow-up. The mean 5-year risk of conversion for all patients in the study group ranged from 2.9% to 52.3% during follow-up. The mean slope of risk change over time was 0.37±0.81% increase/y. The mean slope for patients who reached a POAG endpoint was significantly greater than for those who did not (1.3±0.78 vs. 0.042±0.52%/y, P<0.01). In each patient, the mean risk of POAG conversion increased almost 10-fold when comparing the best case scenario with the worst case scenario (5.0% vs. 45.7%, P<0.01). The estimated 5-year risk of conversion to POAG among untreated OHT patients varies significantly during follow-up, with a trend toward increasing over time. Within the same individual, the estimated risk can

Tear clearance and ocular symptoms in patients treated with preservative-free prostaglandins.

PubMed

Giménez-Gómez, R; García-Catalán, M R; Gallardo-Galera, J M

2013-03-01

To assess the effects on dry eye symptoms and tear dynamics of switching from a prostaglandin with a preservative to a preservative-free prostaglandin. Fourteen patients (N=28 eyes) with open-angle glaucoma and dry eye symptons, treated with preserved latanoprost, travoprost or bimatoprost were included in this uncontrolled prospective study. Ocular symptoms were analysed using a validated ocular surface disease questionnaire and ocular signs were assessed with tear clearance, Schirmer and tear function index test (TFI=Schirmer/clearance). Patients were assigned to preservative-free tafluprost treatment, and measurements were repeated 4 weeks after change of medication. Wilcoxon test and Spearman correlation coefficient were used in the statistical analysis. No statistically significant difference in intraocular pressure (IOP) was observed after switching to tafluprost. Mean IOP at baseline was 20.4 mmHg (SD2.2) and after 4 weeks 19.9 mmHg (SD2.6), (P>.05). The mean questionnaire score significantly decreased from 9.7 (SD3.7) at baseline to 5.4 (SD2.7) after one month (P<.001). No significant differences in tear clearance, Schirmer or TFI were found (P>.05). At baseline, tear clearance=0.13 (SD0.07), Schirmer=10.7 mm (SD6) and TFI=80 (48-156). After 4 weeks, tear clearance=0.1(SD0.07), Schirmer=9.5 mm (3.9) and TFI=104 (48-216). A significant association between questionnaire score and tear clearance after 4 weeks was observed (Spearman coefficient=0.62; P=.014). Switching from preservative prostaglandin with a preservative to preservative-free tafluprost treatment improves dry eye symptoms and suggests an improvement in TFI. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

The Magnitude and Time Course of IOP Change in Response to Body Position Change in Nonhuman Primates Measured Using Continuous IOP Telemetry

PubMed Central

Turner, Daniel C.; Samuels, Brian C.; Huisingh, Carrie; Girkin, Christopher A.

2017-01-01

Purpose To study the effect and time course of body position changes on IOP in nonhuman primates. Methods We recorded continuous bilateral IOP measurements with a wireless telemetry implant in three rhesus macaques in seven different body positions. IOP measurements were acquired in the seated-upright, standing, prone, supine, right and left lateral decubitus positions (LDPs), and head-down inverted positions. Continuous IOP was recorded for 90 seconds in each position before returning to a supine reference position until IOP stabilized; measurements were averaged after IOP stabilized at each position. Results Head-down inversion increased IOP an average of 8.9 mm Hg, compared to the supine reference. In the LDP, IOP decreased an average of 0.5 mm Hg in the nondependent eye (i.e., the higher eye), while the fellow dependent (i.e., lower) eye increased an average of 0.5 mm Hg, compared to supine reference. Standing and seated positions decreased IOP 1.5 and 2.2 mm Hg, respectively, compared with supine reference. IOP changes occurred within 4 to 15 seconds of a body position change, and timing was affected by the speed at which body position was changed. Compared to the IOP in the supine position, the IOP in the inverted, prone, and seated positions was significantly different (P = 0.0313 for all). The IOP in the standing position was not statistically different from the IOP in the supine position (P = 0.094). In addition, the IOP was significantly different between the nondependent eye and the dependent eye in the LDPs compared to the supine position (P = 0.0313). Conclusions Body position has a significant effect on IOP and those changes persist over time. PMID:29228251

Do Intra-anal Bowel Management Devices Reduce Incontinence-Associated Dermatitis and/or Pressure Injuries?

PubMed

Beeson, Terrie; Eifrid, Bethany; Pike, Caitlin A; Pittman, Joyce

The purpose of this article was to examine the evidence and provide recommendations related to the effectiveness of intra-anal bowel management systems including intra-anal bowel catheters and rectal trumpets in reducing incontinence-associated dermatitis and pressure injuries. Does the use of an intra-anal bowel management system (intra-anal bowel catheter or rectal trumpet) reduce incontinence-associated skin damage and/or hospital-acquired pressure injuries in the acute care adult patient population? A search of the literature was performed by a trained university librarian, which resulted in 133 articles that examined intra-anal bowel management systems (intra-anal bowel catheter and rectal trumpet), incontinence-associated dermatitis, and pressure injuries. A systematic approach was used to review titles, abstracts, and text yielding 6 studies that met inclusion criteria. Strength of the evidence was rated using rating methodology from Essential Evidence Plus: Levels of evidence and Oxford Center for Evidence-based Medicine, adapted by Gray and colleagues. Five of the 6 studies reported positive results concerning the effectiveness of intra-anal bowel management systems to reduce incontinence-associated dermatitis and/or pressure injuries. One randomized control trial found no improvement in incontinence-associated dermatitis in the intra-anal bowel management system (intra-anal bowel catheter or rectal trumpet) groups or pressure injuries as compared to usual care. The strength of the evidence for the identified studies was moderate (2 level A, 3 level B, and 1 level C). An important finding in 2 of the studies was the safety of the intra-anal bowel management systems-both intra-anal bowel catheter and rectal trumpet. Evidence indicates intra-anal bowel management system (intra-anal bowel catheters and rectal trumpet) provides a viable option for fecal incontinence management and these devices reduce incontinence-associated dermatitis and/or pressure injuries.

Bimatoprost-Loaded Ocular Inserts as Sustained Release Drug Delivery Systems for Glaucoma Treatment: In Vitro and In Vivo Evaluation

PubMed Central

Franca, Juçara Ribeiro; Foureaux, Giselle; Fuscaldi, Leonardo Lima; Ribeiro, Tatiana Gomes; Rodrigues, Lívia Bomfim; Bravo, Renata; Castilho, Rachel Oliveira; Yoshida, Maria Irene; Cardoso, Valbert Nascimento; Fernandes, Simone Odília; Cronemberger, Sebastião; Ferreira, Anderson José; Faraco, André Augusto Gomes

2014-01-01

The purpose of the present study was to develop and assess a novel sustained-release drug delivery system of Bimatoprost (BIM). Chitosan polymeric inserts were prepared using the solvent casting method and characterized by swelling studies, infrared spectroscopy, differential scanning calorimetry, drug content, scanning electron microscopy and in vitro drug release. Biodistribution of 99mTc-BIM eye drops and 99mTc-BIM-loaded inserts, after ocular administration in Wistar rats, was accessed by ex vivo radiation counting. The inserts were evaluated for their therapeutic efficacy in glaucomatous Wistar rats. Glaucoma was induced by weekly intracameral injection of hyaluronic acid. BIM-loaded inserts (equivalent to 9.0 µg BIM) were administered once into conjunctival sac, after ocular hypertension confirmation. BIM eye drop was topically instilled in a second group of glaucomatous rats for 15 days days, while placebo inserts were administered once in a third group. An untreated glaucomatous group was used as control. Intraocular pressure (IOP) was monitored for four consecutive weeks after treatment began. At the end of the experiment, retinal ganglion cells and optic nerve head cupping were evaluated in the histological eye sections. Characterization results revealed that the drug physically interacted, but did not chemically react with the polymeric matrix. Inserts sustainedly released BIM in vitro during 8 hours. Biodistribution studies showed that the amount of 99mTc-BIM that remained in the eye was significantly lower after eye drop instillation than after chitosan insert implantation. BIM-loaded inserts lowered IOP for 4 weeks, after one application, while IOP values remained significantly high for the placebo and untreated groups. Eye drops were only effective during the daily treatment period. IOP results were reflected in RGC counting and optic nerve head cupping damage. BIM-loaded inserts provided sustained release of BIM and seem to be a promising system

Ocular changes in primary hypothyroidism.

PubMed

Ozturk, Banu T; Kerimoglu, Hurkan; Dikbas, Oguz; Pekel, Hamiyet; Gonen, Mustafa S

2009-12-29

To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy. Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT), anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus) and cup to disc ratio (C/D), mean retinal thickness and mean retinal nerve fiber layer (RNFL) thickness measurements with optical coherence tomography (OCT) in addition to ophthalmological examination preceeding the replacement therapy and at the 1(st), 3(rd )and 6(th )months of treatment. The mean age of the patients included in the study were 40.58 +/- 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP) revealed no significant change. The mean CCT was 538.05 +/- 3.85 mu initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 +/- 0.03 and the mean retinal thickness was 255.83 +/- 19.49 mu initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered. Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio.

Asymmetries and Visual Field Summaries as Predictors of Glaucoma in the Ocular Hypertension Treatment Study

PubMed Central

Levine, Richard A.; Demirel, Shaban; Fan, Juanjuan; Keltner, John L.; Johnson, Chris A.; Kass, Michael A.

2007-01-01

Purpose To evaluate whether baseline visual field data and asymmetries between eyes predict the onset of primary open-angle glaucoma (POAG) in Ocular Hypertension Treatment Study (OHTS) participants. Methods A new index, mean prognosis (MP), was designed for optimal combination of visual field thresholds, to discriminate between eyes that developed POAG from eyes that did not. Baseline intraocular pressure (IOP) in fellow eyes was used to construct measures of IOP asymmetry. Age-adjusted baseline thresholds were used to develop indicators of visual field asymmetry and summary measures of visual field defects. Marginal multivariate failure time models were constructed that relate the new index MP, IOP asymmetry, and visual field asymmetry to POAG onset for OHTS participants. Results The marginal multivariate failure time analysis showed that the MP index is significantly related to POAG onset (P < 0.0001) and appears to be a more highly significant predictor of POAG onset than either mean deviation (MD; P = 0.17) or pattern standard deviation (PSD; P = 0.046). A 1-mm Hg increase in IOP asymmetry between fellow eyes is associated with a 17% increase in risk for development of POAG. When threshold asymmetry between eyes existed, the eye with lower thresholds was at a 37% greater risk of development of POAG, and this feature was more predictive of POAG onset than the visual field index MD, though not as strong a predictor as PSD. Conclusions The MP index, IOP asymmetry, and binocular test point asymmetry can assist in clinical evaluation of eyes at risk of development of POAG. PMID:16936102

Latanoprostene Bunod 0.024% versus Timolol Maleate 0.5% in Subjects with Open-Angle Glaucoma or Ocular Hypertension: The APOLLO Study.

PubMed

Weinreb, Robert N; Scassellati Sforzolini, Baldo; Vittitow, Jason; Liebmann, Jeffrey

2016-05-01

To compare the diurnal intraocular pressure (IOP)-lowering effect of latanoprostene bunod (LBN) ophthalmic solution 0.024% every evening (qpm) with timolol maleate 0.5% twice daily (BID) in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT). Phase 3, randomized, controlled, multicenter, double-masked, parallel-group clinical study. Subjects aged ≥18 years with a diagnosis of OAG or OHT in 1 or both eyes. Subjects were randomized (2:1) to a 3-month regimen of LBN 0.024% qpm or timolol 0.5% 1 drop BID. Intraocular pressure was measured at 8 am, 12 pm, and 4 pm of each postrandomization visit (week 2, week 6, and month 3). Adverse events were recorded throughout the study. The primary efficacy end point was IOP in the study eye measured at each of the 9 assessment time points. Secondary efficacy end points included the proportion of subjects with IOP ≤18 mmHg consistently at all 9 time points and the proportion of subjects with IOP reduction ≥25% consistently at all 9 time points. Of 420 subjects randomized, 387 completed the study (LBN 0.024%, n = 264; timolol 0.5%, n = 123). At all 9 time points, the mean IOP in the study eye was significantly lower in the LBN 0.024% group than in the timolol 0.5% group (P ≤ 0.002). At all 9 time points, the percentage of subjects with mean IOP ≤18 mmHg and the percentage with IOP reduction ≥25% were significantly higher in the LBN 0.024% group versus the timolol 0.5% group (mean IOP ≤18 mmHg: 22.9% vs. 11.3%, P = 0.005; IOP reduction ≥25%: 34.9% vs. 19.5%, P = 0.001). Adverse events were similar in both treatment groups. In this phase 3 study, LBN 0.024% qpm demonstrated significantly greater IOP lowering than timolol 0.5% BID throughout the day over 3 months of treatment. Latanoprostene bunod 0.024% was effective and safe in these adults with OAG or OHT. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Development of a Δ9-Tetrahydrocannabinol Amino Acid-Dicarboxylate Prodrug With Improved Ocular Bioavailability

PubMed Central

Adelli, Goutham R.; Bhagav, Prakash; Taskar, Pranjal; Hingorani, Tushar; Pettaway, Sara; Gul, Waseem; ElSohly, Mahmoud A.; Repka, Michael A.; Majumdar, Soumyajit

2017-01-01

Purpose The aim of the present study was to evaluate the utility of the relatively hydrophilic Δ9-tetrahydrocannabinol (THC) prodrugs, mono and di-valine esters (THC-Val and THC-Val-Val) and the amino acid (valine)-dicarboxylic acid (hemisuccinate) ester (THC-Val-HS), with respect to ocular penetration and intraocular pressure (IOP) lowering activity. THC, timolol, and pilocarpine eye drops were used as controls. Methods THC-Val, THC-Val-Val, and THC-Val-HS were synthesized and chemically characterized. Aqueous solubility and in vitro transcorneal permeability of THC and the prodrugs, in the presence of various surfactants and cyclodextrins, were determined. Two formulations were evaluated for therapeutic activity in the α-chymotrypsin induced rabbit glaucoma model, and the results were compared against controls comprising of THC emulsion and marketed timolol maleate and pilocarpine eye drops. Results THC-Val-HS demonstrated markedly improved solubility (96-fold) and in vitro permeability compared to THC. Selected formulations containing THC-Val-HS effectively delivered THC to the anterior segment ocular tissues in the anesthetized rabbits: 62.1 ng/100 μL of aqueous humor (AH) and 51.4 ng/50 mg of iris ciliary bodies (IC) (total THC). The duration and extent of IOP lowering induced by THC-Val-HS was 1 hour longer and 10% greater, respectively, than that obtained with THC and was comparable with the pilocarpine eye drops. Timolol ophthalmic drops, however, exhibited a longer duration of activity. Both THC and THC-Val-HS were detected in the ocular tissues following multiple dosing of THC-Val-HS in conscious animals. The concentration of THC in the iris-ciliary bodies at the 60- and 120-minute time points (53 and 57.4 ng/50 mg) were significantly greater than that of THC-Val-HS (24.2 and 11.3 ng/50 mg). Moreover, at the two time points studied, the concentration of THC was observed to increase or stay relatively constant, whereas THC-Val-HS concentration decreased

Comparison of Ocular Pulse Amplitude Lowering Effects of Preservative-Free Tafluprost and Preservative-Free Dorzolamide-Timolol Fixed Combination Eyedrops.

PubMed

Seo, Du Ri; Ha, Seung Joo

2015-01-01

To compare the ocular pulse amplitude (OPA) lowering effects of preservative-free tafluprost and dorzolamide-timolol fixed combination (DTFC) using dynamic contour tonometry. In total, 66 eyes of 66 patients with normal tension glaucoma (NTG) (n = 34) or primary open angle glaucoma (POAG) (n = 32) were included. Patients were divided into two groups: the preservative-free tafluprost-treated group (n = 33) and the preservative-free DTFC-treated group (n = 33). Intraocular pressure (IOP) was measured using Goldmann applanation tonometry (GAT). OPA was measured using dynamic contour tonometry; corrected OPA (cOPA) was calculated at baseline and at 1 week and 1, 3, and 6 months after treatment. After 6 months of treatment, tafluprost significantly reduced IOP (P < 0.001). The OPA lowering effects differed significantly between the two treatment groups (P = 0.003). The cOPA-lowering effect of tafluprost (1.09 mmHg) was significantly greater than that of DTFC (0.36 mmHg) after 6 months of treatment (P = 0.01). Tafluprost and DTFC glaucoma treatments provided marked OPA and IOP lowering effects. Tafluprost had a greater effect than DTFC; thus, this drug is recommended for patients at risk of glaucoma progression, due to the high OPA caused by large fluctuations in IOP.

Effect of sublingual application of cannabinoids on intraocular pressure: a pilot study.

PubMed

Tomida, Ileana; Azuara-Blanco, Augusto; House, Heather; Flint, Maggie; Pertwee, Roger G; Robson, Philip J

2006-10-01

The purpose of this study was to assess the effect on intraocular pressure (IOP) and the safety and tolerability of oromucosal administration of a low dose of delta-9-tetrahydrocannabinol (Delta-9-THC) and cannabidiol (CBD). A randomized, double-masked, placebo-controlled, 4 way crossover study was conducted at a single center, using cannabis-based medicinal extract of Delta-9-THC and CBD. Six patients with ocular hypertension or early primary open angle glaucoma received a single sublingual dose at 8 AM of 5 mg Delta-9-THC, 20 mg CBD, 40 mg CBD, or placebo. Main outcome measure was IOP. Secondary outcomes included visual acuity, vital signs, and psychotropic effects. Two hours after sublingual administration of 5 mg Delta-9-THC, the IOP was significantly lower than after placebo (23.5 mm Hg vs. 27.3 mm Hg, P=0.026). The IOP returned to baseline level after the 4-hour IOP measurement. CBD administration did not reduce the IOP at any time. However, the higher dose of CBD (40 mg) produced a transient elevation of IOP at 4 hours after administration, from 23.2 to 25.9 mm Hg (P=0.028). Vital signs and visual acuity were not significantly changed. One patient experienced a transient and mild paniclike reaction after Delta-9-THC administration. A single 5 mg sublingual dose of Delta-9-THC reduced the IOP temporarily and was well tolerated by most patients. Sublingual administration of 20 mg CBD did not reduce IOP, whereas 40 mg CBD produced a transient increase IOP rise.

Correlating Corneal Biomechanics and Ocular Biometric Properties with Lamina Cribrosa Measurements in Healthy Subjects.

PubMed

Pérez Bartolomé, Francisco; Martínez de la Casa, Jose María; Camacho Bosca, Irene; Sáenz-Francés, Federico; Aguilar Munoa, Soledad; Martín Juan, Alberto; Garcia-Feijoo, Julian

2018-01-01

To examine interrelations between corneal biomechanics, ocular biometric variables and optic disc size (ODS), lamina cribosa depth (LCD) or thickness (LCT) in a healthy population. In a cross-sectional case-control study, the following measurements were made in 81 eyes of 81 participants: axial length, anterior chamber depth, lens thickness, and central corneal thickness using the optical biometer Lenstar LS900; and corneal hysteresis (CH), corneal resistance factor (CRF), Goldman-correlated intraocular pressure (IOPg), and corneal-compensated IOP (IOPcc) using the Ocular Response Analyzer. Serial horizontal enhanced depth imaging optical coherence tomography (EDI OCT) B-scans of the optic nerve head were obtained in each participant. Mean ODS, mean LCD, and mean LCT were measured in 11 equally spaced horizontal B-scans, excluding the LC insertion area under Bruch's membrane and scleral rim. LCD was measured in 74 of 81 eyes (91.36%); LCT in 60/81 (75.3%); ODS in 81/81 (100%). CRF was poorly, but significantly, correlated with LCT (Pearson's R = 0.264; P = 0.045). IOPcc, IOPg, CH, and ocular biometrics variables were poorly (non-significantly) correlated with LCD, LCT, and ODS. CRF was poorly but directly correlated with LCT. No association was detected between CH or ocular biometric variables and ODS, LCD, or LCT.

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2012 CFR

2012-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2013 CFR

2013-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2014 CFR

2014-04-01

... System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2855 Implantable Intra-aneurysm Pressure Measurement System. (a) Identification. Implantable intra...

Comparison of Ocular Outcomes in Two 14-Day Bed Rest Studies

NASA Technical Reports Server (NTRS)

Cromwell, Ronita L.; Zanello, S. B.; Yarbough, P. O.; Tabbi, G.; Vizzeri, G.

2012-01-01

Reports of astronauts' visual changes have raised concern about ocular health during long-duration spaceflight. Some of these findings include globe flattening with hyperopic shifts, choroidal folds, optic disc edema, retinal nerve fiber layer (RNFL) thickening, and cotton wool spots. While the etiology remains unknown, it is hypothesized that, in predisposed individuals, hypertension in the brain may follow cephalad fluid shifts during spaceflight. This possible mechanism of ocular changes may also apply to analogous cases of idiopathic intracranial hypertension (IIH) or pseudotumor cerebri on Earth patients. Head-down t ilt (HDT) bed rest is a spaceflight analog that induces cephalad fluid shifts. Previous studies of the HDT position demonstrated body fluid shifts associated with changes in intraocular pressure (IOP) but the conditions of bed rest varied among experiments, making it difficult to compare data and draw conclusions. For these reasons, vision evaluation of bed rest subjects was implemented for NASA bed rest studies since 2010, in an attempt to monitor vision health in subjects subjected to bed rest. Vision monitoring is thus currently performed in all NASA-conducted bed rest campaigns

Fitness Level Modulates Intraocular Pressure Responses to Strength Exercises.

PubMed

Vera, Jesús; Jiménez, Raimundo; Redondo, Beatríz; Cárdenas, David; García-Ramos, Amador

2018-06-01

Purpose/Aim: The execution of strength exercises has demonstrated to increase the intraocular pressure (IOP) levels, and it may have a negative impact on the ocular health. We aimed to explore the influence of fitness level on the acute IOP response to strength exercises performed under different loading conditions, as well as to test whether the IOP responses differ between the bench press and jump squat when performed against the same relative loads. Forty military personnel males were divided in two subgroups (20 high-fit and 20 low-fit) based on their relative to body mass one-repetition maximum (1-RM). Participants performed an incremental loading test in the bench press and jump squat exercises, and IOP was assessed before and after each repetition by rebound tonometry. IOP increased immediately after executing both exercises (p < 0.01 in both cases), being the magnitude of the IOP increment positively and linearly associated with the increment of the load in both groups (i.e., high-fit and low-fit) and in both exercises (R 2 range: 0.81-1.00). Higher fitness level attenuated the IOP rise produced by both exercises (p < 0.01 in both cases). The bench press induced higher IOP increments than the jump squat for both groups at relative loads of ~50%1-RM and ~60%1-RM (p < 0.01 in all cases). These data indicate that IOP increases as a consequence of performing strength exercises, being the increment accentuated with the increase of the load and in the bench press compared to the jump squat exercise. Of special importance would be that the IOP responses were significantly reduced in high-fit individuals. These findings should be addressed in glaucoma patients.

Corneal biomechanical changes in diabetes mellitus and their influence on intraocular pressure measurements.

PubMed

Sahin, Afsun; Bayer, Atilla; Ozge, Gökhan; Mumcuoğlu, Tarkan

2009-10-01

To investigate possible corneal biomechanical changes in patients with diabetes mellitus and understand the influence of such changes on intraocular pressure measurements. The study group was composed of 120 eyes from 61 healthy control subjects and 81 eyes from 43 diabetic subjects. IOP was measured first with an ocular response analyzer (ORA) and subsequently with a Goldmann applanation tonometer (GAT). Central corneal thickness (CCT) was measured with an ultrasonic pachymeter attached to the ORA. Axial length (AL), anterior chamber depth (ACD), and keratometry readings were acquired with partial coherence laser interferometry during the same visit before all IOP and CCT determinations were made. Corneal hysteresis (CH) was found to be significantly lower in diabetic patients when compared with healthy control subjects (9.51 +/- 1.82 mm Hg vs. 10.41 +/- 1.66 mm Hg, P < 0.0001). There was no significant difference in terms of corneal resistance factor (CRF; P = 0.8). Mean CCT, GAT IOP, Goldmann-correlated IOP (IOPg), and corneal-compensated IOP (IOPcc) were significantly higher in diabetic patients than in healthy control subjects (P = 0.01 for CCT, P < 0.0001 for GAT IOP, IOPg, and IOPcc). Diabetes affects corneal biomechanics and results in lower CH values than those in healthy control subjects, which may cause clinically relevant high IOP measurements independent of CCT.

Ultra-high speed OCT allows measurement of intraocular pressure, corneal geometry, and corneal stiffness using a single instrument

NASA Astrophysics Data System (ADS)

Singh, Manmohan; Han, Zhaolong; Nair, Achuth; Schill, Alexander; Twa, Michael D.; Larin, Kirill V.

2018-02-01

Screening for ocular diseases, such as glaucoma and keratoconus, includes measuring the eye-globe intraocular pressure (IOP) and corneal biomechanical properties. However, currently available clinical tools cannot quantify corneal tissue material parameters, which can provide critical information for detecting diseases and evaluating therapeutic outcomes. Here, we demonstrate measurement of eye-globe IOP, corneal elasticity, and corneal geometry of in situ porcine corneas with a technique termed applanation optical coherence elastography (Appl-OCE) with single instrument. We utilize an ultrafast phase-sensitive optical coherence tomography system comprised of a 4X buffered Fourier domain mode-locked swept source laser with an Ascan rate of 1.5 MHz and a 7.3 kHz resonant scanner. The IOP was measured by imaging the response of in situ porcine corneas to a large force air-puff. As with other noncontact tonometers, the time when the cornea was applanated during the inwards and outwards motion was correlated to a measure air-pressure temporal profile. The IOP was also measured with a commercially available rebound tonometer for comparison. The stiffness of the corneas was assessed by directly imaging and analyzing the propagation of a focused micro air-pulse induced elastic wave, and the corneal geometry was obtained from the OCT structural image. Our results show that corneal thickness decreased as IOP increased, and that corneal stiffness increased with IOP. Moreover, the IOP measurements made by Appl-OCE were more closely correlated with the artificially set IOP than the rebound tonometer, demonstrating the capabilities of Appl-OCE to measure corneal stiffness, eye-globe IOP, and corneal geometry with a single instrument.

Evaluation of ocular and general safety following repeated dosing of dexamethasone phosphate delivered by transscleral iontophoresis in rabbits.

PubMed

Patane, Michael A; Schubert, William; Sanford, Thomas; Gee, Raymond; Burgos, Melissa; Isom, William P; Ruiz-Perez, Begona

2013-10-01

To evaluate the toxicokinetics and tolerability (local ocular and general toxicity) of the anti-inflammatory agent, dexamethasone phosphate (a prodrug of dexamethasone) delivered to the eye in rabbits by transscleral iontophoresis. Female rabbits (n=6/group) received dexamethasone phosphate (40 mg/mL ophthalmic solution, EGP-437) transsclerally to the right eye (OD) using the Eyegate(®) II ocular iontophoresis delivery system once biweekly for 24 consecutive weeks at current doses of 10, 14, and 20 mA-min and current levels up to, and including -4 mA for 3.5-5 min. The study included 2 control groups (n=6/group): (1) a noniontophoresis control [an ocular applicator-loaded citrate buffer (placebo) without current] and (2) an iontophoresis control (a citrate buffer plus cathode iontophoresis at 20 mA-min, -4 mA for 5 min). Recoverability was evaluated 4 weeks following the last dose in 2 animals per group. The left eye (OS) was untreated and served as an internal control for each animal. Ocular and general safety of dexamethasone phosphate and dexamethasone were assessed. Other evaluations included toxicokinetics, ophthalmic examinations, intraocular pressure (IOP) measurements, electroretinographs, clinical observations, body weight, hematology and serum chemistry, gross necropsy, organ weight, and microscopic histopathology. The biweekly transscleral iontophoresis with either the citrate buffer or dexamethasone phosphate at cathodic doses up to, and including 20 mA-min and currents up to, and including -4 mA for 24 weeks was well-tolerated. Transient signs of conjunctival hyperemia and chemosis, mild corneal opacity, and fluorescein staining of the cornea were noted and attributed to expected ocular reactions to the temporary placement of the ocular applicator and application of iontophoresis. There were no dexamethasone phosphate-, dexamethasone-, or iontophoresis-related effects on IOP, electroretinography, or histopathology. Reductions in body weight gain

[Reliability and reproducibility of introcular pressure (IOP) measurement with the Icare® Home rebound tonometer (model TA022) and comparison with Goldmann applanation tonometer in glaucoma patients].

PubMed

Valero, B; Fénolland, J-R; Rosenberg, R; Sendon, D; Mesnard, C; Sigaux, M; Giraud, J-M; Renard, J-P

2017-12-01

The Icare ® Home tonometer is a new rebound tonometer, developed for intraocular pressure (IOP) self-monitoring. The main objective of our study was to evaluate the reliability and reproducibility of measurements taken with the Icare ® Home tonometer in glaucoma patients compared to the Goldmann applanation tonometer. A secondary objective was to investigate factors that could influence the reproducibility of these measurements. Fifty-two glaucoma patients were included in this prospective, non-randomized, monocentric study. IOP measurements were performed on the right eye and then on the left eye in the following order (3 measurements of IOP for each method): air tonometer (T-Air), Icare ® Home tonometer by the patient (RT-P), Icare ® Home tonometer by an ophthalmologist (RT-O), Goldmann applanation tonometer (GAT). Forty-four patients (85%) managed to take their IOP on both eyes with the Icare ® Home tonometer. Mean IOPs were 14.35±3.93mmHg (T-Air), 13.43±4.65mmHg (RT-P), 14.13±4.29mmHg (RT-O), 14.74±3.84mmHg (GAT). The intraclass correlation indices (ICC) on the 3 repeated IOP measurements were 0.924, 0.872, 0.947 and 0.957, respectively. Bland-Altman analysis found a mean difference (bias) between GAT and RT-P, between GAT and RT-O, and between RT-O and RT-P, respectively, of 1.31, 0.61 and 0.70mmHg, with a 95% confidence interval of -3.34 to 5.96, -3.91 to 5.14 and -3.44 to 4.84mmHg, respectively. The reproducibility of the measurements taken with the Icare ® Home tonometer did not vary according to corneal thickness or age of the patients. The Icare ® Home tonometer provides reliable and reproducible IOP values in glaucoma patients, although it appears to slightly underestimate the IOP measurements compared to the Goldmann applanation tonometer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Viscoelastic Tamponade Applied to the Ocular Surface for Enhanced Control of Gaseous Egress From the Anterior Chamber During Final Bubble Titration in DMEK Surgery: The "Polite" Burp.

PubMed

Sales, Christopher S; Fernandez, Ana Alzaga; Anwar, Zane

2018-07-01

To present a novel technique for enhancing the surgeon's control over the volume of air or gas that is "burped" from the anterior chamber during final bubble and intraocular pressure (IOP) titration in Descemet membrane endothelial keratoplasty. After ascertaining that the intracameral bubble is either too large and/or has rendered IOP too high, a bead of ophthalmic viscoelastic is applied to the ocular surface over a paracentesis incision, which is then depressed in the usual fashion to burp gas from the anterior chamber. The weight and viscosity of the viscoelastic create a tamponade that slows the egress of gas from the anterior chamber, thereby making it more controllable. If the bubble size or IOP needs to be reduced at the conclusion of the Descemet membrane endothelial keratoplasty procedure, application of ophthalmic viscoelastic over the paracentesis can enhance the surgeon's control over the volume of gas burped from the anterior chamber, thereby reducing the tendency to swing between a bubble that is too large or too small.

Evaluation of retinal ganglion cell function after intraocular pressure reduction measured by pattern electroretinogram in patients with primary open-angle glaucoma.

PubMed

Karaśkiewicz, Joanna; Penkala, Krzysztof; Mularczyk, Maciej; Lubiński, Wojciech

2017-04-01

To evaluate retinal ganglion cell (RGC) function after intraocular pressure (IOP) reduction measured by pattern electroretinogram (PERG) in patients with newly diagnosed, non-treated preperimetric and early stages of primary open-angle glaucoma (POAG). Twenty-four eyes from 24 patients with POAG: 11 eyes with preperimetric glaucoma and 13 eyes with early glaucoma received Ganfort ® (bimatoprost + timolol) once a day for a period of 1 month. Before and after the treatment, following measurements were analyzed: IOP, mean ocular perfusion pressure (MOPP), peak time of P50 and amplitude of P50 and N95 waves in PERG (ISCEV standard 2012). Correlations between PERG P50 and N95 waves, IOP and MOPP were calculated. After therapy, IOP significantly decreased in all eyes, on average 31%. Significant increase in MOPP in all eyes on average 14% was detected. PERG amplitude of P50 and N95 waves increased in 75 and 79% eyes, respectively, on average P50 by 28% and N95 by 38%. There were no significant interactions between the change of PERG parameters in time and stage of glaucoma. Significant IOP-lowering therapy can improve RGC function measured by PERG, in patients with preperimetric and early stages of POAG.

A 4-week, dose-ranging study comparing the efficacy, safety and tolerability of latanoprost 75, 100 and 125 μg/mL to latanoprost 50 μg/mL (xalatan) in the treatment of primary open-angle glaucoma and ocular hypertension

PubMed Central

2012-01-01

Background Several studies have investigated the effect of latanoprost on intraocular pressure (IOP). We compared the IOP-lowering effects of three higher concentrations of latanoprost with the commercially available concentration of 0.005% (50 μg/mL) in patients with primary open-angle glaucoma or ocular hypertension. Methods Treatment-naive subjects or those receiving IOP-lowering medication with baseline IOP levels of ≥24 mmHg and ≤36 mmHg in at least one eye after washout were randomized to receive an evening dose of latanoprost 50, 75, 100, or 125 μg/mL for 4 weeks. At weeks 1, 2, 3, and 4, ocular examinations were performed and IOP was measured. Ocular symptoms and adverse events were monitored. The primary efficacy endpoint was the change in IOP from baseline to week 4 at 8 a.m. and 4 p.m. for the per protocol (PP) population using a "worse eye" analysis. Secondary efficacy endpoints were change in IOP at each time point from baseline across all visits, and percentage change in IOP from baseline to week 4 at 8 a.m. Results In all, 282 patients were randomized and treated; 274 were included in the PP population. Treatment groups were similar at baseline; 68% were diagnosed with primary open-angle glaucoma. Mean baseline IOP levels were comparable across treatments. There were no statistically significant differences in IOP reductions from baseline to week 4 at either time point between those treated with higher concentrations of latanoprost versus those receiving 50 μg/mL. Least squares mean IOP changes at 8 a.m. were −10.13, -9.59, -10.02, and −9.06 mmHg for latanoprost 50, 75, 100, and 125 μg/mL, respectively, and at 4 p.m. were −8.90, -8.29, -8.81, and −8.34 mmHg, respectively. Results of secondary efficacy analyses supported those of the primary analysis. Conjunctival hyperemia, the most commonly reported adverse event, occurred in 16.9%, 18.6%, 20.8% and 15.9% of subjects receiving latanoprost 50, 75, 100, and

Preservative-free versus preserved latanoprost eye drops in patients with open-angle glaucoma or ocular hypertension.

PubMed

Aptel, Florent; Choudhry, Reena; Stalmans, Ingeborg

2016-08-01

This study compared the efficacy, safety, and pharmacokinetics of a preservative-free latanoprost formulation to an established, benzalkonium chloride (BAK) containing formulation for the treatment of open-angle glaucoma or ocular hypertension. This was a phase II, randomized, cross-over, investigator-masked, multi-center, pilot study (NCT01494753). A total of 30 untreated adult patients (aged ≥18 years) with primary open angle glaucoma, pseudo-exfoliative glaucoma, pigmentary glaucoma, or ocular hypertension received either preservative-free or preserved latanoprost once daily in both eyes for 6 weeks, before crossing over to receive the other treatment. Efficacy (intraocular pressure [IOP] at 8 am, midday, 4 pm and 8 pm, and global efficacy assessment by investigator), safety (adverse events, ocular symptoms and global tolerance, slit lamp examination, funduscopy, visual field examination, visual acuity, and heart rate), and pharmacokinetics were assessed at Days 0, 42, and 84. Both treatments resulted in a reduction in IOP that was similar for the preservative-free and the preserved formulation at all time points. Similarly, the overall diurnal reduction was similar in both groups (6.3 mmHg [27.9% reduction] and 6.4 mmHg [28.1% reduction] for preserved and preservative-free latanoprost, respectively). There were no differences in global efficacy assessment or in the safety and tolerance of each treatment. Systemic concentrations of latanoprost were very low; AUC0-30 and Cmax were lower and tmax was longer for preservative-free latanoprost. Preservative-free latanoprost showed similar efficacy at all time points compared to BAK preservative containing formulation, with no difference in tolerance, allowing progression to phase III clinical development.

Macular Pigment Optical Density and Ocular Pulse Amplitude in Subjects with Different Axial Lengths and Refractive Errors.

PubMed

Czepita, Maciej; Karczewicz, Danuta; Safranow, Krzysztof; Czepita, Damian

2015-06-13

The purpose of our study was to: (1) investigate the macular pigment optical density (MPOD) and ocular pulse amplitude (OPA) in subjects with different axial lengths (AL) and refractive errors (RE); (2) determine if there is a correlation between MPOD and OPA; and (3) evaluate whether MPOD and OPA depend on intraocular pressure (IOP). This study included 140 eyes of 70 subjects - 17 men and 53 women, aged 18 to 29 years (mean: 22.5 years; SD=2.8). Every examined person underwent a thorough eye examination including: visual acuity, anterior segment and fundus examination, keratometry, auto-refractometry, and MPOD, OPA, AL, and IOP measurements. The obtained results were analyzed statistically using Statistica 10 software. P values of <0.05 were considered statistically significant. The following refractive errors were selected: emmetropia (34 eyes), hyperopia (18 eyes), low myopia (60 eyes), medium myopia (19 eyes), and high myopia (9 eyes). It has been established that the OPA increases with the rise in the spherical equivalents (SE) (Rs=+0.38, P<0.001), while the increase in AL correlates with the decrease of OPA (Rs=-0.40, P<0.001). The increase in IOP correlates with the rise in the OPA (Rs=+0.20, P<0.05). There were no significant correlations between IOP and SE or AL. (1) MPOD is not correlated with the OPA in subjects with different AL and RE; (2) OPA decreases with the rise of AL; (3) OPA decreases with the fall of the SE; and (4) OPA increases with the rise in IOP.

Ocular changes in primary hypothyroidism

PubMed Central

2009-01-01

Background To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy. Findings Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT), anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus) and cup to disc ratio (C/D), mean retinal thickness and mean retinal nerve fiber layer (RNFL) thickness measurements with optical coherence tomography (OCT) in addition to ophthalmological examination preceeding the replacement therapy and at the 1st, 3rd and 6th months of treatment. The mean age of the patients included in the study were 40.58 ± 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP) revealed no significant change. The mean CCT was 538.05 ± 3.85 μ initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 ± 0.03 and the mean retinal thickness was 255.83 ± 19.49 μ initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered. Conclusions Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio. PMID:20040111

Efficacy and tolerability of fixed-combination brinzolamide/timolol in Latin American patients with open-angle glaucoma or ocular hypertension previously on brimonidine/timolol fixed combination.

PubMed

Alezzandrini, Arturo; Hubatsch, Douglas; Alfaro, Rene

2014-09-01

Fixed-combination glaucoma medications are commonly used to achieve target intraocular pressure (IOP) reduction in patients uncontrolled with monotherapy; however, ocular discomfort associated with eye drops can decrease adherence. This study assessed the efficacy and tolerability of twice-daily fixed-combination brinzolamide 1%/timolol 0.5% (BRINZ/TIM-FC) in Latin American patients transitioned from fixed-combination brimonidine 0.2%/timolol 0.5% (BRIM/TIM-FC) because of insufficient IOP control or treatment intolerance. This 8-week, open-label, prospective study was conducted at six sites in Argentina, Chile, and Mexico. Enrolled patients were aged ≥18 years with open-angle glaucoma (including primary, exfoliative, or pigment-dispersion glaucoma) or ocular hypertension with IOP of 19-35 mmHg in ≥1 eye at baseline (on BRIM/TIM-FC). Patients self-administered BRINZ/TIM-FC to both eyes at 8 a.m. and 8 p.m. daily for 8 weeks. The primary and secondary efficacy endpoints were mean IOP change from baseline at week 8 and percentage of patients achieving target IOP (≤18 mmHg) at week 8, respectively. Exploratory endpoints included patient and investigator preference for treatment at week 8. Adverse events (AEs) were assessed as the safety endpoint. Fifty patients (mean ± SD age, 66.7 ± 11.5 years) received BRINZ/TIM-FC, and 49 were included in the intent-to-treat population. Mean ± SD IOP was significantly reduced from baseline after 8 weeks of treatment with BRINZ/TIM-FC (-3.6 ± 3.0 mmHg; P < 0.0001, Wilcoxon signed-rank test; 17.1% reduction). Overall, 55.3% of patients achieved IOP ≤18 mmHg at week 8. Significantly more patients (89.4%) and investigators (95.7%) preferred BRINZ/TIM-FC to BRIM/TIM-FC (both P < 0.0001, exact binomial test). Of the 13 AEs observed, 8 were related to BRINZ/TIM-FC; the most common treatment-related AEs were eye irritation (n = 4) and abnormal sensation in the eye (n = 2). BRINZ/TIM-FC provides an

Clinical, legal and ethical implications of the intra-ocular (off-label) use of bevacizumab (avastin)--a South African perspective.

PubMed

Jansen, Rita-Marié; Gouws, Chris

2009-06-01

Choroidal neovascularisation is a potentially visually devastating element of various forms of eye pathology. Recent research has focused on neurovascular age-related macular degeneration (AMD) as a cause. AMD can be classified as being exudative (wet) or atrophic (dry). Wet AMD is characterised by a pathological process in which new blood vessels develop in the choroids, causing leakage of fluid and haemorrhage under the retina and leading to localised serous detachment and loss of central vision. Vascular endothelial growth factor (VEGF) stimulates growth of neovascular membranes. Treatments have until recently yielded disappointing results. Ophthalmologists are using intra-ocular injections of bevacizumab (Avastin), an anti-VEGF, to treat AMD. Avastin appears to be safe and effective in the short term, but its intra-ocular administration is entirely off-label. Avastin is registered for treating metastatic colorectal and breast cancer. The off-label use of medication is an important part of mainstream, legitimate medical practice worldwide. Lawyers representing plaintiffs injured by drugs increasingly encounter off-label use claims. From a legal/ethical point of view the off-label use of medication represents a delicate balance between the statutory regulation of medication and a physician's prerogative to prescribe medication that in his or her medical opinion will be beneficial to the patient. The main reason for the controversy created by the off-label use of Avastin is that there are anti-VEGF drugs on the market that have formal approval for the treatment of AMD (and other eye conditions). Lucentis, for example, is extremely expensive, with treatment cost approximately 50 times that of Avastin. Many patients suffering from AMD and macular oedema cannot afford the registered product. The off-label use of Avastin has passed the innovative or experimental stages, as ophthalmologists have used it regularly and openly for a long time, with good success. Such use

Numerical analysis of specific absorption rate in the human head due to a 13.56 MHz RFID-based intra-ocular pressure measurement system.

PubMed

Hirtl, Rene; Schmid, Gernot

2013-09-21

A modern wireless intra-ocular pressure monitoring system, based on 13.56 MHz inductively coupled data transmission, was dosimetrically analyzed with respect to the specific absorption rate (SAR) induced inside the head and the eye due to the electromagnetic field exposure caused by the reader antenna of the transmission system. The analysis was based on numerical finite difference time domain computations using a high resolution anatomical eye model integrated in a modern commercially available anatomical model of a male head. Three different reader antenna configurations, a 7-turn elliptic (30 mm × 50 mm) antenna at 12 mm distance from the eye, a flexible circular antenna (60 mm diameter, 8 turns on 2 mm substrate) directly attached to the skin, and a circular 7-turn antenna (30 mm diameter at 12 mm distance to the eye) were analyzed, respectively. Possible influences of the eye-lid status (closed or opened) and the transponder antenna contained in a contact lens directly attached to the eye were taken into account. The results clearly demonstrated that for typical reader antenna currents required for proper data transmission, the SAR values remain far below the limits for localized exposure of the head, as defined by the International Commission for Non-Ionizing Radiation Protection. Particularly the induced SAR inside the eye was found to be substantially (orders of magnitudes for typical reader antenna currents in the order of 1 A turn) below values which have been reported to be critical with respect to thermally induced adverse health effects in eye tissues.

Effect of caffeine on the intraocular pressure in patients with primary open angle glaucoma

PubMed Central

Chandra, Peeyush; Gaur, Ajit; Varma, Shambhu

2011-01-01

Purpose Coffee and tea are very common nonalcoholic beverages. However, their intake, particularly that of coffee, has been suggested to increase intraocular pressure (IOP) in patients with open angle glaucoma/ocular hypertension. The causative agent has been suggested to be their caffeine content. The objective of this study was to determine if this represents a direct caffeine effect. This study was therefore done using pure caffeine applied directly to the eyes. Methods The study was conducted with five human volunteers with open angle glaucoma/ ocular hypertension. IOP was measured using a Perkins applanation tonometer. Eye drops of 1% caffeine were prepared in-home. Following the initial (basal) measurement of the IOP, 50 μL of the eye drop preparation was instilled in the eye at 0-, 4-, and 6-hour intervals. IOPs were measured 30 minutes after each instillation. A second study was also undertaken following the first. In this study, the same patients instilled the eye drops three times per day for 1 week at home and then returned to the clinic on day 7. They were then again treated with caffeine eye drops as above and IOPs measured. Results In the 1-day study, the mean basal IOP was 23.6 ± 2.80 mmHg. Thirty minutes after instillation of the drops as described, the pressures were 23.2 ± 1.93, 22.2 ± 1.99, and 22.6 ± 2.31. The basal reading was taken at 10 am and another reading was then taken at 10.30 am. Additional eye drops were instilled at 2 and 8 pm and readings taken 30 minutes after each instillation. In the 1 week study, the basal value was 22.6 ± 2.32. After instillation of the drops as above the values were 23 ± 2.16, 22.4 ± 2.27, and 23 ± 1.94. Conclusion Administration of caffeine into the eyes of patients did not have any effect on IOP and it remained relatively unchanged. This was true in the 1-day study as well as in the 1-week study. A cumulative effect was not visible. The results therefore demonstrate that caffeine has no significant

Factors determining the level and changes in intra-articular pressure in the knee joint of the dog.

PubMed Central

Nade, S; Newbold, P J

1983-01-01

Intra-articular pressure levels were determined for joint positions throughout the normal physiological range of movement of dogs' knee joints. Change in joint position resulted in change in intra-articular pressure. It was demonstrated that intra-articular pressure is highest with the joint in the fully flexed position. Minimum pressure was recorded at a position between 80 degrees and 120 degrees. Minimum pressures were usually subatmospheric. The rate of change of joint position affected intra-articular pressure. The relationship of intra-articular pressure and joint position before and after full flexion demonstrated a hysteresis effect; the pressures were lower than for the same joint position before flexion. Maintenance of the joint in the fully flexed position for increasing periods of time between repeated movement cycles resulted in a similar reduction, of constant magnitude, in pressure between joint positions before and after each period of flexion. However, there was also a progressive decrease in pressure for all joint angles over the total number of movement cycles. There is a contribution to intra-articular pressure of joint capsular compliance and fluid movement into and out of the joint (both of which are time-dependent). The recording of intra-articular pressure in conscious, upright dogs revealed similar pressure levels to those measured in anaesthetized supine dogs. The major determinants of intra-articular pressure in normal dog knee joints include joint size, synovial fluid volume, position of joint, peri-articular tissue and joint anatomy, membrane permeability, capsular compliance, and movement of fluid into and out of the joint. Images Fig. 1 PMID:6875957

Laser in Glaucoma and Ocular Hypertension (LiGHT) trial. A multicentre, randomised controlled trial: design and methodology.

PubMed

Gazzard, Gus; Konstantakopoulou, Evgenia; Garway-Heath, David; Barton, Keith; Wormald, Richard; Morris, Stephen; Hunter, Rachael; Rubin, Gary; Buszewicz, Marta; Ambler, Gareth; Bunce, Catey

2018-05-01

The Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial aims to establish whether initial treatment with selective laser trabeculoplasty (SLT) is superior to initial treatment with topical medication for primary open-angle glaucoma (POAG) or ocular hypertension (OHT). The LiGHT Trial is a prospective, unmasked, multicentre, pragmatic, randomised controlled trial. 718 previously untreated patients with POAG or OHT were recruited at six collaborating centres in the UK between 2012 and 2014. The trial comprises two treatment arms: initial SLT followed by conventional medical therapy as required, and medical therapy without laser therapy. Randomisation was provided online by a web-based randomisation service. Participants will be monitored for 3 years, according to routine clinical practice. The target intraocular pressure (IOP) was set at baseline according to an algorithm, based on disease severity and lifetime risk of loss of vision at recruitment, and subsequently adjusted on the basis of IOP control, optic disc and visual field. The primary outcome measure is health-related quality of life (HRQL) (EQ-5D five-level). Secondary outcomes are treatment pathway cost and cost-effectiveness, Glaucoma Utility Index, Glaucoma Symptom Scale, Glaucoma Quality of Life, objective measures of pathway effectiveness, visual function and safety profiles and concordance. A single main analysis will be performed at the end of the trial on an intention-to-treat basis. The LiGHT Trial is a multicentre, pragmatic, randomised clinical trial that will provide valuable data on the relative HRQL, clinical effectiveness and cost-effectiveness of SLT and topical IOP-lowering medication. ISRCTN32038223, Pre-results. © 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.

Effect of Nocturnal Intermittent Peritoneal Dialysis on Intraocular Pressure and Anterior Segment Optical Coherence Tomography Parameters.

PubMed

Chong, Ka Lung; Samsudin, Amir; Keng, Tee Chau; Kamalden, Tengku Ain; Ramli, Norlina

2017-02-01

To evaluate the effect of nocturnal intermittent peritoneal dialysis (NIPD) on intraocular pressure (IOP) and anterior segment optical coherence tomography (ASOCT) parameters. Systemic changes associated with NIPD were also analyzed. Observational study. Nonglaucomatous patients on NIPD underwent systemic and ocular assessment including mean arterial pressure (MAP), body weight, serum osmolarity, visual acuity, IOP measurement, and ASOCT within 2 hours both before and after NIPD. The Zhongshan Angle Assessment Program (ZAAP) was used to measure ASOCT parameters including anterior chamber depth, anterior chamber width, anterior chamber area, anterior chamber volume, lens vault, angle opening distance, trabecular-iris space area, and angle recess area. T tests and Pearson correlation tests were performed with P<0.05 considered statistically significant. A total of 46 eyes from 46 patients were included in the analysis. There were statistically significant reductions in IOP (-1.8±0.6 mm Hg, P=0.003), MAP (-11.9±3.1 mm Hg, P<0.001), body weight (-0.7±2.8 kg, P<0.001), and serum osmolarity (-3.4±2.0 mOsm/L, P=0.002) after NIPD. All the ASOCT parameters did not have any statistically significant changes after NIPD. There were no statistically significant correlations between the changes in IOP, MAP, body weight, and serum osmolarity (all P>0.05). NIPD results in reductions in IOP, MAP, body weight, and serum osmolarity in nonglaucomatous patients.

A controlled evaluation of oral screen effects on intra-oral pressure curve characteristics.

PubMed

Knösel, Michael; Jung, Klaus; Kinzinger, Gero; Bauss, Oskar; Engelke, Wilfried

2010-10-01

The purpose of this study was to quantify the impact of oral screen (OS) application on intra-oral pressure characteristics in three malocclusion groups. Fifty-six randomly recruited participants (26 males and 30 females) who met the inclusion criteria of either an Angle Class I occlusal relationships or Angle Class II1 or II2 malocclusions, were assigned by dentition to group I (n = 31), group II1 (n = 12), or group II2 (n = 13). Two 3 minute periods of intra-oral pressure monitoring were conducted on each participant, using two different oral end fittings connected to a piezo-resistive relative pressure sensor: (1) a flexible OS and (2) a small-dimensioned air-permeable end cap (EC), which was placed laterally in the premolar region, thus recording intra-oral pressure independent of the influence of the OS. Pressure curve characteristics for both periods and between the malocclusion groups were evaluated with reference to the frequency of swallowing peaks, duration, and altitude of negative pressure plateau phases and the area under the pressure curve. Statistical analysis was undertaken using analysis of variance (ANOVA), the Wilcoxon Mann-Whitney test, and spearman correlation coefficient. A median number of two peaks (median height -20.9 mbar) and three plateau phases (median height of -2.3 mbar) may be regarded as normative for normal occlusion subjects during a 3 minute period, at rest. OS application raised the median average duration and height of intra-oral negative pressure plateau phases in the II1 subjects, exceeding those of group I, but less than the plateau duration in group II2. Median peak heights were distinctively lower in groups I and II1 during OS application. It is concluded that additional training for extension of intra-oral pressure phases may be a promising approach to pre-orthodontic Class II division 1 treatment.

Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty.

PubMed

Stunf Pukl, Spela; Drnovšek-Olup, Brigita

2018-02-01

To evaluate the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) or ocular hypertension (OHT), when performed with laser pulse duration of 1 ns compared with standard 3-5 ns. Bilateral SLT with a 532 nm Q-switched neodymium-doped yttrium aluminium garnet laser was conducted in 30 patients (60 eyes) with POAG (n = 5), NTG (n = 2) or OHT (n = 23). Pulse duration was 1 ns in the right eye (30 eyes; cases) and 3-5 ns in all left eyes (controls). Main outcome measures were IOP at 1 h, 1 day, 8 weeks and 6 months, and the rate of adverse ocular tissue reactions in all eyes. Mean 1 ns and 3-5 ns SLT IOPs were 24.1 and 24.3 mmHg, respectively, at baseline. No statistically significant difference in mean 1 ns and 3-5 ns SLT IOP was observed at 1 h (P = 0.761), 1 day (P = 0.758), 8 weeks (P = 0.352) and 6 months postoperatively (P = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (P = 0.529). Treatment with both laser pulse durations resulted in minor ultrastructural changes in the drainage angle. SLT performed with a 1 ns laser pulse duration does not appear to be inferior to SLT performed with the standard 3-5 ns duration at lowering IOP in treatment-naïve patients with POAG, NTG or OHT.

[Contribution of hemodynamic disturbances in magistral vessels to optic neuropathy progression and ocular tension changes in endocrine ophthalmopathy].

PubMed

Likhvantseva, V G; Kharlap, S I; Korosteleva, E V; Solomatina, M V; Mel'nikova, M V; Budanova, S V; Regeb, A Ben; Vygodin, V A

2015-01-01

to investigate the contribution of various hemodynamic disturbances in magistral vessels to optic neuropathy (ON) progression and ocular tension changes in endocrine ophthalmopathy (EOP). A total of 39 patients (78 eyes) with subclinical EOP (clinical activity score, CAS ≤ 2) associated with Graves' disease (n = 32, 64 eyes) or autoimmune thyroiditis (n = 7, 14 eyes) were examined. Orbit echography was performed in all patients. Blood flow was assessed with a Voluson 730 PRO ultrasound diagnostic system ("Kretz", Austria) in triplex mode (B-scan, color Doppler flow mapping in combination with pulse-wave Doppler). Thus obtained hemodynamic parameters in ophthalmic artery, central retinal artery (CRA), central retinal vein (CRV), short posterior ciliary arteries (SPCA), and long posterior ciliary arteries (LPCA) were analyzed. To reveal the role of hemodynamic disturbances in the above mentioned vessels in ON progression and eye pressure maintenance, the patients were divided into 7 groups. Only those eyes, whose peripheral indices were increased by more than 25% of normal values and diastolic blood flow decreased by not less than 25%, were selected for further study. Intraocular pressure changes were evaluated by group mean (Mmean = M ± m mmHg), optic neuropathy progression--by the difference in group mean depth (dB) and number of scotomas between the first and the last visit (6 months of observation). In almost all types of perfusion disturbances, the resultant chronic ocular ischemia causes a decrease in IOP. The only exception, as shown, is simultaneous involvement of CRA, SPCA, and LPCA. The level of blood flow disturbance determines the severity of qualitative and quantitative changes in eyes with EOP-associated ON. The rate of ON progression directly correlates with baseline IOP values on day zero. Long-lasting chronic impairment of blood supply of the eyeball leads to reduction in ocular tension and progression of optic neuropathy. Combined perfusion

[Measurement of intra-oral pressure as a contributor for the understanding of pneumophonic coordination impairment in Parkinsonian dysarthria].

PubMed

Sarr, M M; Pinto, S; Jankowski, L; Teston, B; Purson, A; Ghio, A; Régis, J; Peragut, J-C; Viallet, F

2009-12-01

Parkinsonian dysarthria can alter oral communication of the patients in the long-term. Subthalamic nucleus (STN) stimulation represents an interesting therapeutic option, although it does not seem to improve axial signs, of which dysarthric speech. The objective of our study was to contribute to the evaluation of STN stimulation effects on speech impairment and in particular on pneumophonic coordination: this latter parameter can be assessed indirectly by evaluating the temporal progression of the intraoral pressure (IOP) during the expiratory phase; thus, IOP represents the transient expression of subglottal pressure (SGP). Using a dedicated system (EVA2), 20 parkinsonian patients were recorded in ON and OFF STN stimulation conditions in order to evaluate IOP on three measurement points (2nd, 4th and 6th consonants P) during realization of the sentence "Papa ne m'a pas parlé de beau-papa" ("Daddy did not speak to me about daddy-in-law") which corresponds to a breath group. Eleven control subjects were recorded in parallel in order to define reference measurements. STN stimulation improved significantly IOP at the level of the initial measurement points (2nd P and 4th P), with an effect of convergence at the level of the third point (6th P) where the difference between OFF and ON STIM conditions was not significant any more. In addition, the performance of the patients ON STIM remained much lower than that of the control subjects. Our results raise the significant concept that IOP measurement can be regarded as a relevant indicator for dysarthria in Parkinson's disease. They also show that the improvement of pneumophonic coordination by STN stimulation is restricted to the initial period of the expiratory phase, confirming again the mitigated and controversial effect of STN stimulation on axial signs.

Identification of biomechanical properties of the cornea: the ocular response analyzer.

PubMed

Terai, Naim; Raiskup, Frederik; Haustein, Michael; Pillunat, Lutz E; Spoerl, Eberhard

2012-07-01

Several methods have been devised for measuring geometric parameters of the cornea but, until now, the biomechanics of the cornea have been largely ignored. The relatively new Ocular Response Analyzer (ORA) provides such biomechanical information. In order to correctly interpret the underlying biomechanics of ORA data, we review reported ORA measurements and provide a compendium of factors influencing these measurements, with discussion of possible explanations for ORA measurement results. This review comprised a literature search using "ocular response analyzer" and "ocular response analyser" as keywords. We reviewed and compared reported results from recent ORA studies so obtained, with an eye to understanding corneal biomechanics. Several ORA biomechanical parameters of the cornea - corneal hysteresis (CH) and corneal resistant factor (CRF) - characterize the viscoelastic properties of the cornea, especially those of the ground substance. The impact on CH and CRF values of various independent factors, e.g. intraocular pressure (IOP), age, central corneal thickness (CCT), and corneal swelling, are discussed. The impact on CH and CRF of treatment-related structural changes of the cornea, i.e. those occurring after refractive surgical procedures, placement of intracorneal rings, and collagen crosslinking (CXL), as well as pathological changes of the cornea, e.g. those resulting from keratoconus, edema, and glaucoma, are discussed. Changes in CRF and CH may be reflective of structural changes in the ground substance of the cornea. Thus, ORA provides invaluable information for delineating biomechanical conditions pertaining to the cornea, with special regard to ocular diseases, e.g. keratoconus and glaucoma.

Bimatoprost 0.03% preservative-free ophthalmic solution versus bimatoprost 0.03% ophthalmic solution (Lumigan) for glaucoma or ocular hypertension: a 12-week, randomised, double-masked trial

PubMed Central

Day, Douglas G; Walters, Thomas R; Schwartz, Gail F; Mundorf, Thomas K; Liu, Charlie; Schiffman, Rhett M; Bejanian, Marina

2013-01-01

Background/Aim To evaluate efficacy and safety of bimatoprost 0.03% preservative-free (PF) ophthalmic solution versus bimatoprost 0.03% (Lumigan) ophthalmic solution for glaucoma or ocular hypertension. Methods In this double-masked, parallel-group study, patients were randomised to bimatoprost PF or bimatoprost for 12 weeks. The primary analysis for non-inferiority was change from baseline in worse eye intraocular pressure (IOP) in the per-protocol population at week 12. For equivalence, it was average eye IOP in the intent-to-treat population at each time point at weeks 2, 6 and 12. Results 597 patients were randomised (bimatoprost PF, n=302 and bimatoprost, n=295). The 95% CI upper limit for worse eye IOP change from baseline was <1.5 mm Hg at each week 12 time point, meeting prespecified non-inferiority criteria. The 95% CI upper limit for the treatment difference for average IOP was 0.69 mm Hg and the lower limit was −0.50 mm Hg at all follow-up time points (hours 0, 2 and 8 at weeks 2, 6 and 12), meeting equivalence criteria. Both treatments showed decreases in mean average eye IOP at all follow-up time points (p<0.001), were safe and well tolerated. Conclusions Bimatoprost PF is non-inferior and equivalent to bimatoprost in its ability to reduce IOP-lowering with a safety profile similar to bimatoprost. PMID:23743437

Allometry and Scaling of the Intraocular Pressure and Aqueous Humour Flow Rate in Vertebrate Eyes.

PubMed

Zouache, Moussa A; Eames, Ian; Samsudin, Amir

2016-01-01

In vertebrates, intraocular pressure (IOP) is required to maintain the eye into a shape allowing it to function as an optical instrument. It is sustained by the balance between the production of aqueous humour by the ciliary body and the resistance to its outflow from the eye. Dysregulation of the IOP is often pathological to vision. High IOP may lead to glaucoma, which is in man the second most prevalent cause of blindness. Here, we examine the importance of the IOP and rate of formation of aqueous humour in the development of vertebrate eyes by performing allometric and scaling analyses of the forces acting on the eye during head movement and the energy demands of the cornea, and testing the predictions of the models against a list of measurements in vertebrates collated through a systematic review. We show that the IOP has a weak dependence on body mass, and that in order to maintain the focal length of the eye, it needs to be an order of magnitude greater than the pressure drop across the eye resulting from gravity or head movement. This constitutes an evolutionary constraint that is common to all vertebrates. In animals with cornea-based optics, this constraint also represents a condition to maintain visual acuity. Estimated IOPs were found to increase with the evolution of terrestrial animals. The rate of formation of aqueous humour was found to be adjusted to the metabolic requirements of the cornea, scaling as Vac(0.67), where Vac is the volume of the anterior chamber. The present work highlights an interdependence between IOP and aqueous flow rate crucial to ocular function that must be considered to understand the evolution of the dioptric apparatus. It should also be taken into consideration in the prevention and treatment of glaucoma.

Allometry and Scaling of the Intraocular Pressure and Aqueous Humour Flow Rate in Vertebrate Eyes

PubMed Central

Zouache, Moussa A.; Eames, Ian; Samsudin, Amir

2016-01-01

In vertebrates, intraocular pressure (IOP) is required to maintain the eye into a shape allowing it to function as an optical instrument. It is sustained by the balance between the production of aqueous humour by the ciliary body and the resistance to its outflow from the eye. Dysregulation of the IOP is often pathological to vision. High IOP may lead to glaucoma, which is in man the second most prevalent cause of blindness. Here, we examine the importance of the IOP and rate of formation of aqueous humour in the development of vertebrate eyes by performing allometric and scaling analyses of the forces acting on the eye during head movement and the energy demands of the cornea, and testing the predictions of the models against a list of measurements in vertebrates collated through a systematic review. We show that the IOP has a weak dependence on body mass, and that in order to maintain the focal length of the eye, it needs to be an order of magnitude greater than the pressure drop across the eye resulting from gravity or head movement. This constitutes an evolutionary constraint that is common to all vertebrates. In animals with cornea-based optics, this constraint also represents a condition to maintain visual acuity. Estimated IOPs were found to increase with the evolution of terrestrial animals. The rate of formation of aqueous humour was found to be adjusted to the metabolic requirements of the cornea, scaling as Vac0.67, where Vac is the volume of the anterior chamber. The present work highlights an interdependence between IOP and aqueous flow rate crucial to ocular function that must be considered to understand the evolution of the dioptric apparatus. It should also be taken into consideration in the prevention and treatment of glaucoma. PMID:26990431

Changes in the retrobulbar hemodynamic parameters after decreasing the elevated intraocular pressure in primary open-angle glaucoma patients.

PubMed

Marjanović, Ivan; Martinez, Antonio; Marjanović, Marija; Milić, Natasa; Kontić, Djordje; Hentova-Senćanić, Paraskeva; Marković, Vujica; Bozić, Marija

2014-01-01

Ocular blood flow (OBF) disturbances could be involved both in the pathogenesis and in progression of glaucomatous damage. The aim of the study was to compare the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior cilliary arteries (SPCA) after decreasing the elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients by using color Doppler imaging (CDI). We examined 60 patients (21 male and 39 female) with diagnosed and treated POAG. Thirty-nine patients had increased IOP (> 25 mm Hg). Peak-systolic velocity (PSV), end-diastolic velocity (EDV), Pourcelot resistance index (RI), and pulsatility index (PI) were assessed in the OA, CRA, and SPCA. IOP was measured both with the Goldmann Applanation tonometer (GAT) and with the Dynamic Contour tonometer (DCT), three times respectively. Ocular pulse amplitude (OPA) was measured using DCT. The retrobulbar parameters between the baseline and after IOP reduction showed no difference in measurements. After Bonferroni correction (p < or = 0.0056, alpha/9) statistical significance was recorded only in the following retrobulbar hemodynamic parameters; DCT (29.8 +/- 6.2 vs. 15.5 +/- 5.0), GAT (33.8 +/- 9.0 vs. 15.0 +/- 6.6) and OPA measurements (4.3 +/- 1.0 vs. 3.0 +/- 1.6), as compared to the baseline. There was no correlation between the changes in IOP measured with either DCT or GAT and changes in the hemodynamic parameters (p > 0.05 for all). Pearson correlation coefficient (95% CI) showed very good correlation for IOP measurements between DCT and GAT: at baseline 0.83 (0.71 to 0.90) and at the end 0.71 (0.55 to 0.83); p < 0.0001 for both measurements, but without any difference between them (p > 0.05). There was a lack of correlation between the changes in IOP measured with either DCT or GAT and the changes in the hemodynamic parameters.

Effect of Increased Intra-abdominal Pressure on Liver Histology and Hemodynamics: An Experimental Study

PubMed Central

ANTONIOU, EFSTATHIOS A; KAIRI, EVI; MARGONIS, GEORGIOS A; ANDREATOS, NIKOLAOS; SASAKI, KAZUNARI; DAMASKOS, CHRISTOS; GARMPIS, NIKOLAOS; SAMAHA, MARIO; ARGYRA, ERIPHYLI; POLYMENEAS, GEORGE; WEISS, MATTHEW J; PAWLIK, TIMOTHY M; VOROS, DIONYSIOS; KOURAKLIS, GREGORY

2018-01-01

Background: While reduction of portal venous (PV) blood flow has been described in animal models of intra-abdominal hypertension, reports on compensatory changes in hepatic arterial (HA) flow, known as the hepatic arterial buffer response are controversial. Materials and Methods: Pneumoperitoneum with helium was induced in 13 piglets. Hemodynamic measurements and pathological assessment were conducted at baseline and during the three subsequent phases: Phase A: 45 minutes with a stable intra-abdominal pressure of 25 mmHg; phase B: 45 minutes with a stable intra-abdominal pressure of 40 mmHg; and phase C during which the abdomen was re-explored and reperfusion of the liver was allowed to take place. Results: Phase B pressure was significantly greater than phase A pressure in both the PV and the inferior vena cava, demonstrating a positive association between escalating intra-abdominal hypertension and the pressure in these two vessels (all p<0.001). In contrast, HA pressure was comparable between baseline and phase A, while it tended to decrease in phase B. Regarding histology, the most notable abnormality was the presence of inflammatory infiltrates and hepatocyte necrosis. Conclusion: Helium-insufflation increased PV pressure with a partial compensatory decrease of HA pressure. Nonetheless, findings consistent with hepatic ischemia were observed on pathology. PMID:29275303

Evaluation of a contact lens-embedded sensor for intraocular pressure measurement.

PubMed

Twa, Michael D; Roberts, Cynthia J; Karol, Huikai J; Mahmoud, Ashraf M; Weber, Paul A; Small, Robert H

2010-08-01

To evaluate a novel contact lens-embedded pressure sensor for continuous measurement of intraocular pressure (IOP). Repeated measurements of IOP and ocular pulse amplitude (OPA) were recorded in 12 eyes of 12 subjects in sitting and supine positions using 3 configurations of the dynamic contour tonometer: slit-lamp mounted (DCT), hand-held (HH), and contact lens-embedded sensor (CL). The IOP and OPA for each condition were compared using repeated measures ANOVA and the 95% limits of agreement were calculated. The sitting IOP (mean and 95% CI) for each configuration was DCT: 16.3 mm Hg (15.6 to 17.1 mm Hg), HH: 16.6 mm Hg (15.6 to 17.6 mm Hg), and CL: 15.7 mm Hg (15 to 16.3 mm Hg). The sitting OPA for each configuration was DCT: 2.4 mm Hg (2.1 to 2.6 mm Hg), HH: 2.4 mm Hg (2.1 to 2.7 mm Hg), and CL: 2.1 mm Hg (1.8 to 2.3 mm Hg). Supine IOP and OPA measurements with the CL and HH sensors were both greater than their corresponding sitting measurements, but were significantly less with the CL sensor than the HH sensor. The mean difference and 95% Limits of Agreement were smallest for the DCT and CL sensor comparisons (0.7+/-3.9 mm Hg) and widest for the CL and HH sensors (-1.9+/-7.25 mm Hg); these wider limits were attributed to greater HH measurement variability. The CL sensor was comparable to HH and DCT sensors with sitting subjects and is a viable method for measuring IOP and OPA. Supine measurements of IOP and OPA were greater than sitting conditions and were comparatively lower with the CL sensor. HH measurements were more variable than CL measurements and this influenced the Limits of Agreement for both sitting and supine conditions.

Accuracy of a technology-assisted eye exam in evaluation of referable diabetic retinopathy and concomitant ocular diseases.

PubMed

Conlin, Paul R; Asefzadeh, Baharak; Pasquale, Louis R; Selvin, Gerald; Lamkin, Rebecca; Cavallerano, Anthony A

2015-12-01

Digital retinal imaging using store-and-forward technology is used to screen for diabetic retinopathy (DR). Its usefulness in detecting non-diabetic eye diseases is uncertain. We determined the level of agreement between teleretinal imaging supplemented with visual acuity and intraocular pressure (IOP) measurements (ie, technology-assisted eye (TAE) exam) and a comprehensive eye exam in evaluation for DR and non-diabetic ocular conditions. We conducted a prospective, observational study with two parallel evaluations. Patients with diabetes (n=317) had a TAE exam and a comprehensive eye exam on the same day. A subset of participants with normal baseline exams (n=72) had follow-up exams 1 year later. We measured the level of agreement for referable ocular findings. Agreement for referable ocular findings was moderate (n=389, agreement: 77%; κ: 0.55), due in part to ungradable exams (22%). However, about half of the ungradable exams had findings that warranted referral. There was substantial agreement for follow-up exams (n=72, agreement: 93%; κ: 0.63). Among all gradable exams (n=303), the TAE exam had 86% sensitivity and 84% specificity for referable ocular findings, with high agreement (≥94%) for DR and other major ocular diagnoses. There was moderate-to-substantial agreement between a TAE exam and a comprehensive eye exam for referable ocular findings in patients with diabetes. Ungradable exams were a frequent marker of ocular pathology. Teleretinal imaging may be a useful evaluation for both diabetic and non-diabetic ocular conditions. 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/

Subperiosteal Transmission Of Intra-Articular Pressure Between Articulated And Stationary Joints

PubMed Central

Pitkin, Mark; Muppavarapu, Raghuveer; Cassidy, Charles; Pitkin, Emil

2015-01-01

Hydrostatic pressures can be transmitted between synovial capsules. In each of ten rabbits, we simultaneously measured pressure in two joints, one of which was passively ranged, and the other of which was kept stationary. The intra-articular pressure inside the stationary joint changed every time its companion joint was ranged. But the pressure in the stationary joint did not change when the periosteum was transected above the ranged joint. This phenomenon was observed in all four animals that served as their own controls. The study suggests that the intra-articular pressure was transmitted through the space between the periosteum and the bone surface. Alternative explanations, like measurements of venous blood pressure, did not show correlation with hydrostatic pressure changes in the joints. The Floating Skeleton concept suggests a biomechanical rationale for this newly observed phenomenon: that there exists a subperiosteal hydrostatic connection of synovial joints, and that this “net” distributes excess pressures among joints through the periosteal sheath to sustain the integrity of the joint contacting surfaces over a lifetime. PMID:25632015

New fluoroprostaglandin F(2alpha) derivatives with prostanoid FP-receptor agonistic activity as potent ocular-hypotensive agents.

PubMed

Nakajima, Tadashi; Matsugi, Takeshi; Goto, Wakana; Kageyama, Masaaki; Mori, Nobuaki; Matsumura, Yasushi; Hara, Hideaki

2003-12-01

To find new prostanoid FP-receptor agonists possessing potent ocular-hypotensive effects with minimal side effects, we evaluated the agonistic activities of newly synthesized prostaglandin F(2alpha) derivatives for the prostanoid FP-receptor both in vitro and in vivo. The iris constrictions induced by the derivatives and their effects on melanin content were examined using cat isolated iris sphincters and cultured B16 melanoma cells, respectively. The effects of derivative ester forms on miosis and intraocular pressure (IOP) were evaluated in cats and cynomolgus monkeys, respectively. Of these derivatives, 6 out of 12 compounds were more potent iris constrictors, with EC(50) values of 0.6 to 9.4 nM, than a carboxylic acid of latanoprost (EC(50)=13.6 nM). A carboxylic acid of latanoprost (100 microM) significantly increased the melanin content of cultured B16 melanoma cells, but some 15,15-difluoro derivatives, such as AFP-157 and AFP-172, did not. Topically applied AFP-168, AFP-169 and AFP-175 (isopropyl ester, methyl ester and ethyl ester forms, respectively, of AFP-172) induced miosis in cats more potently than latanoprost. AFP-168 (0.0005%) reduced IOP to the same extent as 0.005% latanoprost (for at least 8 h). These findings indicate that 15,15-difluoroprostaglandin F(2alpha) derivatives, especially AFP-168, have more potent prostanoid FP-receptor agonistic activities than latanoprost. Hence, AFP-168 may be worthy of further evaluation as an ocular-hypotensive agent.

Brimonidine 0.2% vs unoprostone 0.15% both added to timolol maleate 0.5% given twice daily to patients with primary open-angle glaucoma or ocular hypertension.

PubMed

Sharpe, E D; Henry, C J; Mundorf, T K; Day, D G; Stewart, J A; Jenkins, J N; Stewart, W C

2005-01-01

To compare the efficacy and safety of brimonidine 0.2% vs unoprostone 0.15%, both added to timolol maleate 0.5% each given twice daily. In this prospective, multi-centred, double-masked, crossover comparison, patients were randomized to one treatment group for a 6-week treatment period, and then crossed over to the opposite treatment. Measurements were performed at 0800, 1000, 1600, 1800, and 2000 h at baseline and at the end of each treatment period. In all, 33 patients entered this trial and 29 completed. The baseline trough intraocular pressure (IOP) was 23.3+/-2.4 and the diurnal curve IOP was 22.0+/-1.3 mmHg. For the brimonidine and timolol maleate treatment group, the trough IOP was 21.6+/-3.3 and the diurnal curve IOP was 19.8+/-2.1 mmHg, while the timolol and unoprostone treatment showed a trough IOP of 20.9+/-3.8 and a diurnal curve IOP of 19.3+/-2.4 mmHg. There was no significant difference between treatment groups at any time point for the diurnal curve, or in the reduction from baseline (P>0.05). Both treatments failed to statistically reduce the IOP from baseline at 1800 h. There was no difference between treatment groups regarding ocular and systemic unsolicited adverse events, but patients admitted to more dryness (P=0.02) and burning upon instillation (P<0.0001) with unoprostone by survey. Brimonidine 0.2% or unoprostone 0.15% added to timolol maleate 0.5% provide similar efficacy and safety throughout the daytime diurnal curve.

Predictive value of early postoperative IOP and bleb morphology in Mitomycin-C augmented trabeculectomy.

PubMed

Esfandiari, Hamed; Pakravan, Mohammad; Loewen, Nils A; Yaseri, Mehdi

2017-01-01

Background : To determine the predictive value of postoperative bleb morphological features and intraocular pressure (IOP) on the success rate of trabeculectomy. Methods : In this prospective interventional case series, we analyzed for one year 80 consecutive primary open angle glaucoma patients who underwent mitomycin-augmented trabeculectomy. Bleb morphology was scored using the Indiana bleb appearance grading scale (IBAGS). Success was defined as IOP ≤15 mmHg at 12 months. We applied a multivariable regression analysis and determined the area under the receiver operating characteristic curve (AUC). Results : The mean age of participants was 62±12.3 years in the success and 63.2±16.3 years in the failure group (P= 0.430) with equal gender distribution (P=0.911). IOPs on day 1, 7 and 30 were similar in both (P= 0.193, 0.639, and 0.238, respectively.) The AUC of IOP at day 1, day 7 and 30 for predicting a successful outcome was 0.355, 0.452, and 0.80, respectively. The AUC for bleb morphology parameters of bleb height, extension, and vascularization, on day 14 were 0.368, 0.408, and 0.549, respectively. Values for day 30 were 0.428, 0.563, and 0.654. IOP change from day 1 to day 30 was a good predictor of failure (AUC=0.838, 95% CI: 0.704 to 0.971) with a change of more than 3 mmHg predicting failure with a sensitivity of 82.5% (95% CI: 68 to 91%) and a specificity of 87.5% (95% CI: 53 to 98%). Conclusions : IOP on day 30 had a fair to good accuracy while bleb features failed to predict success except bleb vascularity that had a poor to fair accuracy.  An IOP increase more than 3 mmHg during the first 30 days was a good predictor of failure.

Sustained Release of an Anti-Glaucoma Drug: Demonstration of Efficacy of a Liposomal Formulation in the Rabbit Eye

PubMed Central

Ang, Marcus; Darwitan, Anastasia; Foo, Selin; Zhen, Ma; Koo, Magdalene; Wong, Tina T.; Venkatraman, Subbu S.

2011-01-01

Topical medication remains the first line treatment of glaucoma; however, sustained ocular drug delivery via topical administration is difficult to achieve. Most drugs have poor penetration due to the multiple physiological barriers of the eye and are rapidly cleared if applied topically. Currently, daily topical administration for lowering the intra-ocular pressure (IOP), has many limitations, such as poor patient compliance and ocular allergy from repeated drug administration. Poor compliance leads to suboptimal control of IOP and disease progression with eventual blindness. The delivery of drugs in a sustained manner could provide the patient with a more attractive alternative by providing optimal therapeutic dosing, with minimal local toxicity and inconvenience. To investigate this, we incorporated latanoprost into LUVs (large unilamellar vesicles) derived from the liposome of DPPC (di-palmitoyl-phosphatidyl-choline) by the film hydration technique. Relatively high amounts of drug could be incorporated into this vesicle, and the drug resides predominantly in the bilayer. Vesicle stability monitored by size measurement and DSC (differential scanning calorimetry) analysis showed that formulations with a drug/lipid mole ratio of about 10% have good physical stability during storage and release. This formulation demonstrated sustained release of latanoprost in vitro, and then tested for efficacy in 23 rabbits. Subconjunctival injection and topical eye drop administration of the latanoprost/liposomal formulation were compared with conventional daily administration of latanoprost eye drops. The IOP lowering effect with a single subconjunctival injection was shown to be sustained for up to 50 days, and the extent of IOP lowering was comparable to daily eye drop administration. Toxicity and localized inflammation were not observed in any treatment groups. We believe that this is the first demonstration, in vivo, of sustained delivery to the anterior segment of the eye

Profile of ocular trauma in industries-related hospital.

PubMed

Shashikala, P; Sadiqulla, Mohammed; Shivakumar, D; Prakash, K H

2013-05-01

Ocular trauma is a worldwide cause of visual morbidity, a significant proportion of which occurs in the industrial workplace and includes a spectrum of simple ocular surface foreign bodies, abrasions to devastating perforating injuries causing blindness. Being preventable is of social and medical concern. A prospective case series study, to know the profile of ocular trauma at a hospital caters exclusively to factory employees and their families, to co-relate their demographic and clinical profile and to identify the risk factors. Patients with ocular trauma who presented at ESIC Model hospital, Rajajinagar, Bangalore, from June 2010 to May 2011 were taken a detailed demographic data, nature and cause of injury, time interval between the time of injury and presentation along with any treatment received. Ocular evaluation including visual acuity, anterior and posterior segment findings, intra-ocular pressure and gonio-scopy in closed globe injuries, X-rays for intraocular foreign body, B-scan and CT scan were done. Data analyzed as per the ocular trauma classification group. The rehabilitation undertaken medically or surgically was analyzed. At follow-up, the final best corrected visual acuity was noted. A total of 306 cases of ocular trauma were reported; predominantly in 20-40 year age group (72.2%) and in men (75%). The work place related cases were 50.7%and of these, fall of foreign bodies led the list. Visual prognosis was poorer in road traffic accidents rather than work place injuries owing to higher occurrence of open globe injuries and optic neuropathy. Finally, 11% of injured cases ended up with poor vision. Targeting groups most at risk, providing effective eye protection, and developing workplace safety cultures may together reduce occupational eye injuries.

Transvesical Intra-Abdominal Pressure Measurement in Newborn: What Is the Optimal Saline Volume Instillation?

PubMed

Defontaine, Anne; Tirel, Olivier; Costet, Nathalie; Beuchée, Alain; Ozanne, Bruno; Gaillot, Théophile; Arnaud, Alexis Pierre; Wodey, Eric

2016-02-01

To determine the optimal saline volume bladder instillation to measure intravesical pressure in critically ill newborns weighing less than 4.5 kg, and to establish a reference of intra-abdominal pressure value in this population. Prospective monocentric study. Neonatal ICU and PICU. Newborns, premature or not, weighing less than 4.5 kg who required a urethral catheter. Patients were classified into two groups according to whether they presented a risk factor for intra-abdominal hypertension. Nine intravesical pressure measures per patient were performed after different volume saline instillation. The first one was done without saline instillation and then by increments of 0.5 mL/kg to a maximum of 4 mL/kg. Linear models for repeated measurements of intravesical pressure with unstructured covariance were used to analyze the variation of intravesical pressure measures according to the conditions of measurement (volume instilled). Pairwise comparisons of intravesical pressure adjusted mean values between instillation volumes were done using Tukey tests, corrected for multiple testing to determine an optimal instillation volume. Forty-seven patients with completed measures (nine instillations volumes) were included in the analysis. Mean intravesical pressure values were not significantly different when measured after instillation of 0.5, 1, or 1.5 mL/kg, whereas measures after instillation of 2 mL/kg or more were significantly higher. The median intravesical pressure value in the group without intra-abdominal hypertension risk factor after instillation of 1 mL/kg was 5 mm Hg (2-6 mm Hg). The optimal saline volume bladder instillation to measure intra-abdominal pressure in newborns weighing less than 4.5 kg was 1 mL/kg. Reference intra-abdominal pressure in this population was found to be 5 mm Hg (2-6 mm Hg).

Effect of Increased Intra-abdominal Pressure on Liver Histology and Hemodynamics: An Experimental Study.

PubMed

Antoniou, Efstathios A; Kairi, Evi; Margonis, Georgios A; Andreatos, Nikolaos; Sasaki, Kazunari; Damaskos, Christos; Garmpis, Nikolaos; Samaha, Mario; Argyra, Eriphyli; Polymeneas, George; Weiss, Matthew J; Pawlik, Timothy M; Voros, Dionysios; Kouraklis, Gregory

2018-01-01

While reduction of portal venous (PV) blood flow has been described in animal models of intra-abdominal hypertension, reports on compensatory changes in hepatic arterial (HA) flow, known as the hepatic arterial buffer response are controversial. Pneumoperitoneum with helium was induced in 13 piglets. Hemodynamic measurements and pathological assessment were conducted at baseline and during the three subsequent phases: Phase A: 45 minutes with a stable intra-abdominal pressure of 25 mmHg; phase B: 45 minutes with a stable intra-abdominal pressure of 40 mmHg; and phase C during which the abdomen was re-explored and reperfusion of the liver was allowed to take place. Phase B pressure was significantly greater than phase A pressure in both the PV and the inferior vena cava, demonstrating a positive association between escalating intra-abdominal hypertension and the pressure in these two vessels (all p<0.001). In contrast, HA pressure was comparable between baseline and phase A, while it tended to decrease in phase B. Regarding histology, the most notable abnormality was the presence of inflammatory infiltrates and hepatocyte necrosis. Helium-insufflation increased PV pressure with a partial compensatory decrease of HA pressure. Nonetheless, findings consistent with hepatic ischemia were observed on pathology. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Tear production and intraocular pressure in canine eyes with corneal ulceration

PubMed Central

Williams, David L.; Burg, Philippa

2017-01-01

This study aimed to evaluate changes in lacrimation and intraocular pressure (IOP) in dogs with unilateral corneal ulceration using the Schirmer tear test (STT) and rebound (TonoVet®) tonometry. IOP and STT values were recorded in both ulcerated and non-ulcerated (control) eyes of 100 dogs diagnosed with unilateral corneal ulceration. Dogs presented with other ocular conditions as their primary complaint were excluded from this study. The mean ± standard deviation for STT values in the ulcerated and control eyes were 20.2±4.6 mm/min and 16.7±3.5 mm/min respectively. The mean ± standard deviation for IOP in the ulcerated and control eyes were 11.9±3.1 mmHg and 16.7±2.6 mmHg respectively. STT values were significantly higher (p<0.000001) in the ulcerated eye compared to the control eye while IOP was significantly lower (p<0.0001). There is an increase in lacrimation and a decrease in IOP in canine eyes with corneal ulceration. The higher tear production in ulcerated eyes shows the importance of measuring STT in both eyes in cases of corneal ulceration, since this increased lacrimation may mask an underlying keratoconjunctivitis sicca only evident in the contralateral eye. The lower IOP in ulcerated eyes is likely to relate to mild uveitic change in the ulcerated eye with a concomitant increase in uveoscleral aqueous drainage. While these changes in tear production and IOP in ulcerated eyes are widely recognised in both human and veterinary ophthalmology, it appears that this is the first controlled documented report of these changes in a large number of individuals. PMID:28616393

Effect of Sedation with Xylazine and Ketamine on Intraocular Pressure in New Zealand White Rabbits

PubMed Central

Holve, Dana L; Gum, Glenwood G; Pritt, Stacy L

2013-01-01

To determine the effects of intravenous and intramuscular xylazine–ketamine on intraocular pressure (IOP) in laboratory rabbits, 10 New Zealand white rabbits received xylazine (0.46 mg/kg) and ketamine (1.5 mg/kg) intravenously whereas another 10 rabbits received intramuscular xylazine (10 mg/kg) and ketamine (50 mg/kg). IOP was measured at baseline and 5, 10, 20, and 25 min after administration in rabbits that were injected intravenously and at baseline and 10, 20, 30, and 45 min in rabbits injected intramuscularly. Baseline IOP (mean ± 1 SD; intravenous group, 20.15 ± 2.24 mm Hg; intramuscular group, 19.03 ± 1.77 mm Hg) did not differ between groups. Compared with baseline values, IOP decreased significantly after intravenous administration at 10, 20, and 25 min (decreases of 2.73, 4.10, and 4.55 mm Hg, respectively) but not at 5 min (decrease of 1.40 mm Hg). IOP in intramuscularly dosed rabbits showed significant differences from baseline at 10, 20, 30, and 45 min (decreases of 2.88, 3.30, 3.95, and 4.60 mm Hg, respectively). In the intravenous group, IOP differed at 10 min compared with 25 min (1.83 mm Hg, P = 0.0143) but not at 20 min compared with 25 min (0.450 mm Hg). In the intramuscular group, differences in IOP at 10 min compared with 20 min, 20 min compared with 30 min, and 30 min compared with 45 min were nonsignificant. Intravenous and intramuscular xylazine–ketamine decreased IOP in laboratory rabbits and may be used safely during ocular procedures for which increased IOP is a concern. PMID:23849448

The evaluation of central corneal thickness and intraocular pressure in conjunction with tear IGF-1 levels in patients with acromegaly.

PubMed

Kan, Emrah; Kan, Elif K; Okuyucu, Ali

2017-08-30

To compare the central corneal thickness (CCT), intraocular pressure (IOP), and tear insulin-like growth factor 1 (IGF-1) levels between patients with acromegaly and a control group and to evaluate the possible effect of tear IGF-1 and duration of the disease on CCT and IOP. We included 31 patients with acromegaly (study group) and 40 age- and sex-matched controls in the study. Patients with acromegaly were divided into 2 subgroups based on disease status (active/inactive). All participants underwent complete ophthalmologic evaluation including CCT and IOP values. Basal tear samples were collected from both groups and tear IGF-1 levels were measured. The CCT, IOP, and tear IGF-1 levels were compared between groups and subgroups and the association between tear IGF-I levels and ocular parameters (CCT, IOP) and disease duration were also evaluated. Central corneal thickness, IOP, and tear IGF-1 levels did not show a significant difference between study and control groups. We also did not find a significant difference in terms of CCT, IOP, or tear IGF-1 levels between subgroups of patients. Correlation analysis did not show an association between the duration of disease and tear IGF-1 levels with CCT or IOP. There was no significant difference in tear IGF-1 levels between patients with acromegaly and controls. Additionally, there was no correlation between disease duration and tear IGF-1 levels with CCT or IOP levels. This lack of association may suggest that tear IGF-1 levels might not have an effect on CCT or IOP findings in patients with acromegaly.

Comparison of different intraocular pressure measurement techniques in normal eyes and post small incision lenticule extraction

PubMed Central

Hosny, Mohamed; Aboalazayem, Fayrouz; El Shiwy, Hoda; Salem, Mohsen

2017-01-01

Purpose The purpose of the study was to determine the accuracy of intraocular pressure (IOP) measurement after small incision lenticule extraction (SMILE) using Goldmann applanation tonometry (GAT) and ocular response analyzer (ORA). Methods This is a prospective clinical study that was conducted on 30 eyes in the interval between February 2016 and September 2016. The age of the patients ranged between 19 and 40 years. The patients underwent SMILE surgery using the femto laser. IOP was measured preoperatively and 1 month postoperatively by both techniques, the GAT and the ORA. Results GAT recorded lower values than ORA values (IOPcc) preoperatively and postoperatively and the difference was statistically significant. Both GAT and ORA IOP measurements decreased after SMILE. There was no statistically significant correlation between the changes in the GAT and ORA readings and the postoperative corneal pachymetry or the lenticule thickness. Both corneal hysteresis and corneal resistance factor showed significant decline after the procedure, which correlated with the lenticule thickness. Conclusion SMILE causes significant reduction in IOP measurement by ORA and GAT. Corneal biomechanics decreases following SMILE and this correlates with lenticule thickness. PMID:28761329

Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery.

PubMed

Cleva, Roberto de; Assumpção, Marianna Siqueira de; Sasaya, Flavia; Chaves, Natalia Zuniaga; Santo, Marco Aurelio; Fló, Claudia; Lunardi, Adriana C; Jacob Filho, Wilson

2014-07-01

Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior). We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique. The mean age of the patients was 56 ± 13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6 ± 0.6 L) and FVC (2.0 ± 0.7 L) with maintenance of FEV1/FVC of 0.8 ± 0.2 in both groups. The maximum intra-abdominal pressure values were similar (p=0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed. Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery.

Systemic Medication and Intraocular Pressure in a British Population

PubMed Central

Khawaja, Anthony P.; Chan, Michelle P.Y.; Broadway, David C.; Garway-Heath, David F.; Luben, Robert; Yip, Jennifer L.Y.; Hayat, Shabina; Wareham, Nicholas J.; Khaw, Kay-Tee; Foster, Paul J.

2014-01-01

Objective To determine the association between systemic medication use and intraocular pressure (IOP) in a population of older British men and women. Design Population-based, cross-sectional study. Participants We included 7093 participants from the European Prospective Investigation into Cancer–Norfolk Eye Study. Exclusion criteria were a history of glaucoma therapy (medical, laser, or surgical), IOP asymmetry between eyes of >5 mmHg, and missing data for any covariables. The mean age of participants was 68 years (range, 48–92) and 56% were women. Methods We measured IOP using the Ocular Response Analyzer. Three readings were taken per eye and the best signal value of the Goldmann-correlated IOP value considered. Participants were asked to bring all their medications and related documentation to the health examination, and these were recorded by the research nurse using an electronic case record form. The medication classes examined were angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, α-blockers, β-blockers, calcium channel blockers, diuretics, nitrates, statins, insulin, biguanides, sulfonylureas, aspirin, and other nonsteroidal anti-inflammatory drugs. We examined associations between medication use and IOP using multivariable linear regression models adjusted for age, sex, and body mass index. Models containing diabetic medication were further adjusted for glycosylated hemoglobin levels. Main Outcome Measures Mean IOP of the right and left eyes. Results Use of systemic β-blockers (−0.92 mmHg; 95% CI, −1.19, −0.65; P<0.001) and nitrates (−0.63 mmHg; 95% CI, −1.12, −0.14; P = 0.011) were independently associated with lower IOP. The observed associations between statin or aspirin use with IOP were no longer significant after adjustment for β-blocker use. Conclusions This is the first population-based study to demonstrate and quantify clinically significant differences in IOP among participants using systemic �

[Biomechanical condition of the cornea as a new indicator for pathological and structural changes].

PubMed

Spörl, E; Terai, N; Haustein, M; Böhm, A G; Raiskup-Wolf, F; Pillunat, L E

2009-06-01

Several methods permit the measurement of geometric parameters of the cornea, but until now biomechanical conditions of the cornea have been ignored (e.g. in refractive corneal surgery). Besides the geometric condition, biomechanical properties of the cornea have been shown to influence applanation measurement of intra-ocular pressure (IOP) and epidemiological studies have identified corneal thickness as an independent risk factor for the development and progression of glaucoma. The aim of this investigation was to characterize the biomechanical properties of the cornea using the ocular response analyzer (ORA). The ocular response analyzer (ORA) is a new method available for non-contact measurement of the biomechanical properties of the cornea. We evaluated the reproducibility of measurements, the difference between static and dynamic factors and the impact of independent factors (e.g. IOP, age, CCT, swelling of the cornea) on 2,500 measurements of corneal hysteresis (CH) and corneal resistance factor (CRF). In a large sample size we observed changes in CH and CRF after refractive surgery procedures (LASIK, UV-A cross-linking, keratoplasty) and in other corneal disorders (keratoconus, corneal dystrophies). CRF and CH changes may reflect structural changes of the cornea. Thus, the ORA provides valuable information for a better understanding and characterization of the biomechanical condition of the cornea, especially with regard to diseases such as keratoconus and glaucoma.

Microbead-induced ocular hypertensive mouse model for screening and testing of aqueous production suppressants for glaucoma.

PubMed

Yang, Qiang; Cho, Kin-Sang; Chen, Huihui; Yu, Dekuang; Wang, Wan-Heng; Luo, Gang; Pang, Iok-Hou; Guo, Wenyi; Chen, Dong Feng

2012-06-20

To characterize the microbead-induced ocular hypertension (OHT) mouse model and investigate its potential use for preclinical screening and evaluation of ocular hypotensive agents, we tested the model's responses to major antiglaucoma drugs. Adult C57BL/6J mice were induced to develop OHT unilaterally by intracameral injection of microbeads. The effects of the most commonly used ocular hypotensive drugs, including timolol, brimonidine, brinzolamide, pilocarpine, and latanoprost, on IOP and glaucomatous neural damage were evaluated. Degeneration of retinal ganglion cells (RGCs) and optic nerve axons were quantitatively assessed using immunofluorescence labeling and histochemistry. Thickness of the ganglion cell complex (GCC) was also assessed with spectral-domain optical coherence tomography (SD-OCT). A microbead-induced OHT model promptly responded to drugs, such as timolol, brimonidine, and brinzolamide, that lower IOP through suppressing aqueous humor production and showed improved RGC and axon survival as compared to vehicle controls. Accordingly, SD-OCT detected significantly less reduction of GCC thickness in mice treated with all three aqueous production suppressants as compared to the vehicle contol-treated group. In contrast, drugs that increase aqueous outflow, such as pilocarpine and latanoprost, failed to decrease IOP in the microbead-induced OHT mice. Microbead-induced OHT mice carry dysfunctional aqueous outflow facility and therefore offer a unique model that allows selective screening of aqueous production suppressant antiglaucoma drugs or for studying the mechanisms regulating aqueous humor production. Our data set the stage for using GCC thickness assessed by SD-OCT as an imaging biomarker for noninvasive tracking of neuronal benefits of glaucoma therapy in this model.

Increased expression of the WNT antagonist sFRP-1 in glaucoma elevates intraocular pressure

PubMed Central

Wang, Wan-Heng; McNatt, Loretta G.; Pang, Iok-Hou; Millar, J. Cameron; Hellberg, Peggy E.; Hellberg, Mark H.; Steely, H. Thomas; Rubin, Jeffrey S.; Fingert, John H.; Sheffield, Val C.; Stone, Edwin M.; Clark, Abbot F.

2008-01-01

Elevated intraocular pressure (IOP) is the principal risk factor for glaucoma and results from excessive impedance of the fluid outflow from the eye. This abnormality likely originates from outflow pathway tissues such as the trabecular meshwork (TM), but the associated molecular etiology is poorly understood. We discovered what we believe to be a novel role for secreted frizzled-related protein-1 (sFRP-1), an antagonist of Wnt signaling, in regulating IOP. sFRP1 was overexpressed in human glaucomatous TM cells. Genes involved in the Wnt signaling pathway were expressed in cultured TM cells and human TM tissues. Addition of recombinant sFRP-1 to ex vivo perfusion-cultured human eyes decreased outflow facility, concomitant with reduced levels of β-catenin, the Wnt signaling mediator, in the TM. Intravitreal injection of an adenoviral vector encoding sFRP1 in mice produced a titer-dependent increase in IOP. Five days after vector injection, IOP increased 2 fold, which was significantly reduced by topical ocular administration of an inhibitor of a downstream suppressor of Wnt signaling. Thus, these data indicate that increased expression of sFRP1 in the TM appears to be responsible for elevated IOP in glaucoma and restoring Wnt signaling in the TM may be a novel disease intervention strategy for treating glaucoma. PMID:18274669

Review of the influence of pigment dispersion and exfoliation glaucoma diagnosis on intraocular pressure in clinical trials evaluating primary open-angle glaucoma and ocular hypertension.

PubMed

Stewart, William C; DeMill, D L; Wirostko, Barbara M; Nelson, Lindsay A; Stewart, Jeanette A

2013-08-01

To evaluate published, randomized, prospective, parallel clinical trials utilizing currently approved glaucoma medications to determine what influence, if any, pigment dispersion (PD) or exfoliation glaucoma (XFG) patients had on the intraocular pressure. A review of clinical trial articles evaluating currently used topical glaucoma medicines. Articles were published between January 1995 and April 2011. If the articles met the inclusion/exclusion criteria, they were analyzed for PD and XFG. Twenty-four articles were included, containing 49 treatment arms that included PD or XFG patients. The range of PD patients was 0% to 4.5%, with a mean of 1.5±0.9%, and for XFG patients 0% to 6.3%, with a mean of 2.2±2.1%. The treatment arms with PD showed a difference in the intraocular pressures (IOPs), for all studies analyzed together, for the baseline IOPs between clinical trials that did and did not include PD patients (8 AM IOPs: with PD 26.5±0.9 mm Hg and without PD 25.8±1.3 mm Hg, P=0.024; and diurnal curve mean IOPs: with PD 25.3±1.1 mm Hg and without PD 24.5±1.3 mm Hg, P=0.024). The XFG treatment arms showed that there was a difference in the IOPs for all studies analyzed together for diurnal baseline IOPs between clinical trials that did and did not include XFG patients (with XFG 25.2±1.2 mm Hg and without XFG 24.3±1.0 mm Hg, P=0.016). Trial designs for prospective, parallel, glaucoma clinical studies that are performed in the United States generally can include PD and XFG patients with only a small impact on the IOP and a low number of such subjects enrolled.

Deformation of the Normal Monkey Optic Nerve Head Connective Tissue Following Acute IOP Elevation within 3-D Histomorphometric Reconstructions

PubMed Central

Yang, Hongli; Downs, J. Crawford; Sigal, Ian A.; Roberts, Michael D.; Thompson, Hillary; Burgoyne, Claude F.

2010-01-01

Purpose To characterize optic nerve head (ONH) connective tissue deformation following acute (15 or 30 minutes) intraocular pressure (IOP) elevation within six adult normal monkeys using 3-D histomorphometry. Methods Trephinated ONH and peripapillary sclera from both eyes of six monkeys, each perfusion fixed with one eye at IOP 10 mmHg and the other at IOP 30 or 45 mmHg by anterior chamber manometer were serial sectioned, 3-D reconstructed, 3-D delineated and quantified using standard parameters. For each monkey, inter-eye differences (high IOP eye minus IOP 10 eye) for each parameter were calculated and compared by ANOVA and EPIDmax both overall and regionally. EPIDmax deformations for each parameter were defined to be those statistically significant differences that exceeded the maximum physiologic inter-eye difference within six bilaterally normal monkeys of a previous report. Results Regional EPIDmax laminar thinning, posterior bowing of the peripapillary sclera, thinning and expansion of the scleral canal were present in most high IOP eyes and were colocalized in those demonstrating the most deformation. Laminar deformation was minimal and not only posterior but in some cases anterior in the high IOP eyes. No increase in deformation was seen in the IOP-45 versus the IOP-30 eyes. Conclusion ONH connective tissue alterations following acute IOP elevation involve regional thinning, stretching and deformation of the lamina cribrosa and peripapillary sclera which are minimal to modest in magnitude. The time-dependent character of these alterations, as well as their compressive, expansile, and shear effects on the contained axons, astrocytes, laminar and posterior ciliary circulations remain to be determined. PMID:19628739

Comparison of Structural and Functional Ocular Outcomes Between 14- and 70 Day Bed Rest

NASA Technical Reports Server (NTRS)

Cromwell, R. L.; Taibbi, G.; Zanello, S. B.; Yarbough, P. O.; Ploutz-Snyder, R. J.; Vizzeri, G.

2016-01-01

Purpose: To compare structural and functional ocular outcomes in healthy human subjects undergoing 14- and/or 70-day head-down-tilt bed rest (HDTBR). We hypothesized the amount of HDTBR-induced ocular changes be affected by the HDTBR duration. Methods: The studies were conducted at the NASA Flight Analogs Research Unit, The University of Texas Medical Branch at Galveston, Galveston, TX. Participants were selected using NASA standard screening procedures. Standardized NASA screening procedures and bed rest conditions (e.g., strict sleep-wake cycle, standardized diet, continuous video monitoring) were implemented in both studies. Participants maintained a 6deg HDTBR position for 14 and/or 70 consecutive days and did not engage in exercise. Weekly ophthalmological examinations were conducted in the sitting (pre/post-bed rest only) and HDT positions. Ocular outcomes of interest included: near best-corrected visual acuity (BCVA); spherical equivalent, as determined by cycloplegic autorefraction; Goldmann applanation tonometry and iCare (Icare Finland Oy, Espoo, Finland) intraocular pressure (IOP) measurement; color vision; red dot test; modified Amsler grid test; confrontational visual field; stereoscopic color fundus photography; Spectralis OCT (Heidelberg Engineering, GmbH, Heidelberg, Germany) retinal nerve fiber layer thickness (RNFLT), peripapillary and macular retinal thicknesses. Mixed-effects linear models were used to compare pre- and post-HDTBR observations between 14- and 70-day HDTBR for our continuously scaled outcomes.

Effect of preservative removal from fixed-combination bimatoprost/timolol on intraocular pressure lowering: a potential timolol dose–response phenomenon

PubMed Central

Shen, Jie; Bejanian, Marina

2016-01-01

Purpose Many patients with glaucoma require combination therapies to achieve target intraocular pressure (IOP) and preserve visual function. Ocular hypotensives often contain a preservative (eg, benzalkonium chloride [BAK]), but preservative-free (PF) formulations have been developed for patients with sensitivity. A Phase III study found the efficacy of bimatoprost 0.03%/timolol 0.5% (bim/tim, Ganfort®) PF to be equivalent to that of preserved bim/tim, although a trend favoring bim/tim PF was observed. As BAK is a corneal penetration enhancer, this literature review aims to explain these findings by exploring the relationship between timolol concentration and its IOP-lowering effect. Methods Systematic searches were performed in Scopus and PubMed for clinical trials published in English between 1960 and July 2014 using the keywords “timolol”, “intraocular pressure”, and the concentrations “1%, 0.5%, OR 0.25%”. Articles that directly compared IOP-lowering effects of ≥2 concentrations of timolol were identified by manual screening, and cross-checked for duplication. Results Seventeen studies that included 10–371 patients were evaluated; the majority were randomized (16/17), double-masked (14/17), and enrolled patients with open-angle glaucoma or ocular hypertension (12/17). All studies investigated timolol in preserved formulations. Timolol concentrations tested ranged from 0.008% to 1.5%. Of 13 studies comparing timolol 0.25% versus 0.5%, two found the 0.25% dose to have greater IOP-lowering effects, and three reported the opposite; eight reported similar IOP lowering. Results also indicate that timolol 0.5% may be more effective than higher concentrations. Conclusion The evidence suggests that timolol may have an inverted U-shaped dose–response curve, and that its optimal IOP-lowering concentration is between 0.25% and 0.5%. Compared with bim/tim, removal of the permeability enhancer BAK in bim/tim PF could have resulted in a lower timolol

Fast circulation of cerebrospinal fluid: an alternative perspective on the protective role of high intracranial pressure in ocular hypertension.

PubMed

Wostyn, Peter; De Groot, Veva; Van Dam, Debby; Audenaert, Kurt; Killer, Hanspeter Esriel; De Deyn, Peter Paul

2016-05-01

As ocular hypertension refers to a condition in which the intraocular pressure is consistently elevated but without development of glaucoma, study of it may provide important clues to factors that may play a protective role in glaucoma. β-amyloid, one of the key histopathological findings in Alzheimer's disease, has been reported to increase by chronic elevation of intraocular pressure in animals with experimentally induced ocular hypertension and to cause retinal ganglion cell death, pointing to similarities in molecular cell death mechanisms between glaucoma and Alzheimer's disease. On the other hand, recent studies have reported that intracranial pressure is higher in patients with ocular hypertension compared with controls, giving rise to the idea that elevated intracranial pressure may provide a protective effect for the optic nerve by decreasing the trans-lamina cribrosa pressure difference. The speculation that the higher intracranial pressure reported in ocular hypertension patients may protect against glaucoma mainly through a lower trans-lamina cribrosa pressure difference remains at least questionable. Here, we present an alternative viewpoint, according to which the protective effect of higher intracranial pressure could be due, at least in part, to a pressure-independent mechanism, namely faster cerebrospinal fluid production leading to increased cerebrospinal fluid turnover with enhanced removal of potentially neurotoxic waste products that accumulate in the optic nerve. This suggests a new hypothesis for glaucoma, which, just like Alzheimer's disease, may be considered then as an imbalance between production and clearance of neurotoxins, including β-amyloid. If confirmed, then strategies to improve cerebrospinal fluid flow are reasonable and could provide a new therapeutic approach for stopping the neurotoxic β-amyloid pathway in glaucoma. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

The effects of nursing activities on the intra-abdominal pressure of patients at risk for intra-abdominal hypertension.

PubMed

Lee, Rosemary K

2017-01-01

Intra-abdominal hypertension (IAH) occurs frequently in critically ill patients, and adds to their morbidity and mortality. There is no published evidence on the effects of nursing activities on the intra-abdominal pressure (IAP) for patients at risk of IAH. The purpose of this study was to identify the effects of hygiene care on the IAP of patients at risk for IAH. Hygiene care was provided to 34 at-risk patients. IAP was measured prior to initiating the hygiene care, immediately after and 10 minutes later. This was a quasi-experimental, pre-test/ post-test design. The 10 minute post-hygiene care measurement of the IAP was significantly lower than the pre or immediate post-measurement of the IAP. There were no significant changes in the mean arterial pressure (MAP) or the abdominal perfusion pressure (APP). It is safe and possibly therapeutic to provide hygiene care to patients at risk for IAH.

Management of Blood Pressure in Patients with Glaucoma.

PubMed

Levine, Russell M; Yang, Alina; Brahma, Venkatesh; Martone, James F

2017-09-19

Ocular perfusion pressure (OPP) is defined as the difference between BP and intraocular pressure (IOP). With low BP comes low OPP and resultant ischemic damage to the optic nerve, leading to glaucoma progression. The purpose of this article is to review the literature on BP as it relates to glaucoma and to create a forum of discussion between ophthalmologists and internal medicine specialists. Both high and low BP has been linked glaucoma. Low BP is particularly associated with glaucoma progression in normal-tension glaucoma (NTG) patients. Patients who have low nighttime BP readings are at highest risk of progression of their glaucoma. Internal medicine specialists and ophthalmologists should consider the relationship between BP and glaucoma when treating patients with concomitant disease. Too-low nighttime BP should be avoided. Ambulatory blood pressure monitoring is a useful tool to identify patients at greatest risk for progression.

Sickle-cell hip necrosis and intraosseous pressure.

PubMed

Mukisi, M M; Bashoun, K; Burny, F

2009-04-01

Osteonecrosis of the femoral head (ONFH) is a frequent complication of sickle-cell disease. Numerous studies have demonstrated increased intraosseous pressure (IOP) in idiopathic necrosis and necrosis secondary to corticotherapy or alcohol poisoning. Several reports have testified to the clinical interest of decompression by drilling which, when performed in the early course of the pathology, can arrest or slow evolution. To the best of our knowledge, no studies have reported IOP increase in sickle-cell ONFH. The present study sought to show that intraosseous hyperpressure plays a role in the physiopathology of sickle-cell, like idiopathic, ONFH. Sixteen intraosseous pressure (IOP) measurements were taken: eight in adult sickle-cell disease patients, four in sickle-cell trait carrying ONFH patients (AS) and four in non-sickle-cell ONFH patients (AA). Arterial blood-pressure equipment with bone-puncture needle was used to measure IOP in the great trochanter body. Three IOP measurements were made after zero calibration: before drilling (direct pressure: IOP-1), after hyperpressure test but before drilling (IOP-2), and after drilling (IOP-3). The present, admittedly short, series displayed elevated predrilling IOP-1 and IOP-2, reduced after drilling (IOP-3). Abnormal IOP fell after drilling performed for evolutive symptomatic ONFH. Significant differences in IOP-1 and IOP-2 were found, these being higher in the "sickle-cell disease" and "sickle-cell trait carriers" groups (p<0.05). Only in the sickle-cell groups was there a significant correlation between pain score and hyperpressure level, with significantly reduced pain after drilling. The elevated IOP levels found in symptomatic sickle-cell hips were comparable to those reported in the literature. Ischemia due to femoral head sinusoid occlusion by falciform globules with secondary intraosseous hyperpressure is the cause of the pain and of the onset and evolution of ONFH. The drilling tunnel acts as a safety valve

Relationship between intraosseous pressures and intra-articular pressure in arthritis of the knee. An experimental study in immature dogs.

PubMed

Bünger, C; Harving, S; Hjermind, J; Bünger, E H

1983-04-01

The influence of chronic synovial inflammation and effusion on the juxta-articular bone haemodynamics in the juvenile knee was studied in 12 immature dogs with Carragheenin-induced unilateral arthritis. Using a fluid filled electromanometric pressure recording system simultaneous pressure measurements were taken from the distal femoral metaphysis, juxta-articular epiphyses and knee joint cavity in general anaesthesia followed by intraosseous phlebographies. During resting conditions the intraosseous pressure of the distal femoral epiphysis and the intra-articular pressure was significantly elevated. The phlebographies showed increased accumulation of contrast in arthritic femoral epiphyses with decreased contrast clearance rate. During increasing intra-articular pressure an augmented vulnerability of the blood supply of the arthritic femoral epiphyses was demonstrated. The results suggests that joint effusion may play an important role in the bone changes in juvenile degenerative arthritis of the knee.

Optimizing novel penetration enhancing hybridized vesicles for augmenting the in-vivo effect of an anti-glaucoma drug.

PubMed

Naguib, Sarah S; Hathout, Rania M; Mansour, Samar

2017-11-01

Usually the topical delivery of ocular drugs poses a great challenge. Accordingly, the work in this study comprised the use of different hybrids of generally regarded as safe (GRAS) oils and surfactants in order to develop and optimize novel acetazolamide (AZD) entrapped-vesicular systems aiming at improving its ocular delivery and reaching better therapeutic outcomes in the treatment of glaucoma. The phospholipid/cholesterol bilayer of the vesicles was enriched with hybrids of Tween 80, Labrasol, Transcutol and Labrafac lipophile WL in different masses and proportions according to a mixture design viz. D-optimal mixture design. Three models were generated comprising three responses: particles size, percentage of entrapment efficiency and amount of drug released after 24 hours (Q24h). The results demonstrated the ability of the penetration enhancing hybrids in modulating the three responses compared to the conventional liposomes. Transmission electron microscope was used to characterize the selected formulations. Sterilization of selected formulations was carried out using gamma radiation and the effect of gamma radiations on entrapment, particle size and in vitro release were studied. The selected sterilized formulations were tested in-vivo on the eyes of albino rabbits in order to evaluate the efficiency of the novel delivery systems on the intra-ocular pressure reduction (IOP) compared to drug solution and the conventional liposomes. The novel formulations proved their efficiency in reducing the IOP to lower values compared to the conventional liposomes, which pose new successful platform for ocular delivery of AZD and other anti-glaucoma drug analogs.

[Use of data display screens and ocular hypertension in local public sector workers].

PubMed

Abellán Torró, Rosana; Merelles Tormo, Antoni

2014-01-01

The main objective of this study is to examine the association between work with data display screens (DDS) and ocular hypertension (OHT). A cross-sectional study among local public sector workers (Diputación Provincial de Valencia). Data from 620 people were collected over 25 months, from periodic medical examinations performed at an occupational health unit. Intraocular pressure (IOP) was obtained with a portable puff tonometer validated for screening, establishing the cut-off point for OHT at 22 mmHg. Both biological characteristics and other work-related variables were taken into account as covariates. Descriptive statistics of the data were obtained, together with nonparametric tests with a level of significance of 95% and logistic regression with p 〈0.1 as the level of significance of the likelihood test. The average age of the study population is 52.8 years. The prevalence of OHT was 3.5% (5.1% among men and 1.2% among women; p=0.012). No significant associations were found between hours of DDS-related work and OHT were found (p=0.395). Logistic regression corroborated the association between gender and OHT, with women less affected (OR = 0.234; 95%CI: 0.068 - 0.799; p=0.020). In our study, no associations were found between time of exposure to data display screens and ocular hypertension. Logistic regression points to a certain association between ocular hypertension and gender, with men being more predisposed. Copyright belongs to the Societat Catalana de Salut Laboral.

[How does central cornea thickness influence intraocular pressure during applanation and contour tonometry?].

PubMed

Schwenteck, T; Knappe, M; Moros, I

2012-09-01

Golmann applanation tonometry represents a well-established procedure for measuring intraocular pressure (IOP). This implies the necessity of an accurate measurement of IOP with the reference tonometer. One example is the contour tonometer Pascal with a measuring probe, adapted to the cornea geometry, for measuring the IOP and the ocular pulse amplitude. There is controversy of how strongly corneal thickness affects the measurement of IOP. We thus analysed, for a number of eyes, the correlation of IOP, as measured by two types of applanation tonometers and one contour tonometer and the central corneal thickness. In all 158 patient eyes were investigated in a clinical comparison of applanation tonometers AT 870 and Ocuton-A. The study was performed by a trained ophthalmologist and the comparison was in accordance with international standard ISO 8612. In addition, the corneal thickness in the vertex was repeatedly determined using an Oculus Pentacam. The potential effect of central corneal thickness on the IOP as measured by the mentioned tonometers was statistically evaluated by rank correlation analysis. We found that the measured IOP values for the three investigated tonometers were not normally distributed. The central corneal thickness values, in contrast, measured on 158 eyes by means of an ultrasound pachymeter and additionally on 235 eyes by the Pentacam, obeyed a Gaussian distribution. For the correlation analysis of both parameters the Spearman linear rank correlation coefficient (r) was considered. We found a very weak (|r| < 0.2) correlation between central corneal thickness and IOP for all 3 tonometers. The softness of the correlation is also illustrated by a large standard deviation of the regression line. A comparison of the different devices for corneal-thickness measurements shows less variance and a smaller variation coefficient when the ultrasoundpachymeter AL-1000 is used. The measured values for IOP are only very weakly correlated to the central

Association Between Cardiovascular and Intraocular Pressure Changes in a 14-Day 6 deg Head Down Tilt (HDT) Bed Rest Study: Possible Implications in Retinal Anatomy

NASA Technical Reports Server (NTRS)

Cromwell, Ronita; Zanello, Susana; Yarbough, Patrice; Ploutz-Snyder, Robert; Taibbi, Giovanni; Vizzeri, Gianmarco

2013-01-01

Visual symptoms and intracranial pressure increase reported in astronauts returning from long duration missions in low Earth-orbit are thought to be related to fluid shifts within the body due to microgravity exposure. Because of this possible relation to fluid shifts, studies conducted in head-down tilt (HDT) bed rest are being monitored for potential changes in ocular health. These measures will also serve to determine whether HDT is a suitable ground-based analog to model subclinical cardiovascular and ocular changes that could shed light on the etiology of the VIIP syndrome observed in spaceflight. Sixteen healthy normotensive (12M, 4F, age range 29-54 years), non-smoker and normal weight subjects, volunteered to participate in a 14 day 6 deg head HDT study conducted at the NASA Flight Analogs Research Unit (FARU). This facility provides standard bed rest conditions (diet, wake/sleep time, time allowed in sunlight) during the time that the subjects stay at the FARU. Cardiovascular parameters were obtained in supine posture at BR-5, BR+0, and BR+3 and ocular monitoring was performed weekly. Intraocular pressure (IOP) increased from pre-bed rest BR-3) to the third day into bed rest (BR+3). Values reached a plateau towards the end of the bed rest phase (BR10) and decreased within the first three days of recovery (BR+2) returning to levels comparable to baseline at BR-3. As expected, most cardiovascular parameters were affected by 14 days of HDT bed rest. Plasma volume decreased as a result of bed rest but recovered to baseline levels by BR+3. Indications of cardiovascular deconditioning included increase in both systolic and diastolic blood pressure and heart rate, and a decrease in stroke volume and cardiac output between BR-5 and BR+3. Due to the experimental design of this study, we were not able to test the hypothesis that fluid shifts might be involved in the IOP increase during the bed rest phase, since cardiovascular measures were not available for those

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implantable Intra-aneurysm Pressure Measurement System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices...

21 CFR 870.2855 - Implantable Intra-aneurysm Pressure Measurement System.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implantable Intra-aneurysm Pressure Measurement System. 870.2855 Section 870.2855 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices...

The impact of intraocular pressure reduction on retrobulbar hemodynamic parameters in patients with open-angle glaucoma.

PubMed

Marjanovic, Ivan; Milic, Natasa; Martinez, Antonio

2012-01-01

To assess the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCA) after decreasing elevated intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) by using color Doppler imaging. A total of 46 eyes from 46 patients with OAG, with elevated IOP, were consecutively included in this prospective study. Peak-systolic velocity, end-diastolic velocity, and Pourcelot resistivity index were assessed in the OA, CRA, and PCA. The IOP was measured with Goldmann applanation tonometer (GAT) and the dynamic contour tonometer (DCT), 3 times respectively. Ocular pulse amplitude (OPA) appeared during the DCT measurement. After decreasing the elevated IOP, measured with both GAT and DCT, the retrobulbar parameters showed no differences as compared with baseline measurements. After Bonferroni correction (p ≤ 0.0042, alpha/12), statistical significance appeared in retrobulbar hemodynamics only in DCT (29.3 ± 6.4 vs 15.5 ± 4.2 mmHg), GAT (33.0 ± 8.3 vs 15.8 ± 7.0 mmHg), and OPA measurements (4.1 ± 1.3 vs 2.7 ± 1.4 mmHg), in comparison to baseline. There was no correlation between the changes in IOP measured with either DCT or GAT and the changes in the retrobulbar hemodynamic parameters (p>0.05 for all). The results of our study suggested a lack of correlation between the changes in IOP, measured with either DCT or GAT, and the changes in the retrobulbar hemodynamic parameters. The results of our study might suggest that the blood flow disturbances found in glaucoma patients are independent of the IOP.

Intra-arterial pressure measurement in neonates: dynamic response requirements.

PubMed

van Genderingen, H R; Gevers, M; Hack, W W

1995-02-01

A computer simulation of a catheter manometer system was used to quantify measurement errors in neonatal blood pressure parameters. Accurate intra-arterial pressure recordings of 21 critically ill newborns were fed into this simulated system. The dynamic characteristics, natural frequency and damping coefficient, were varied from 2.5 to 60 Hz and from 0.1 to 1.4, respectively. As a result, errors in systolic, diastolic and pulse arterial pressure were obtained as a function of natural frequency and damping coefficient. Iso-error curves for 2%, 5% and 10% were constructed. Using these curves, the maximum inaccuracy of any neonatal catheter manometer system can be determined and used in the clinical setting.

Intraocular Pressure and Retinal Nerve Fibre Layer Thickness Changes After Carotid Artery Stenting.

PubMed

Biberoğlu, Esra; Eraslan, Muhsin; Baltacıoğlu, Feyyaz; Midi, İpek

2017-08-01

The aim of this study was to evaluate intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) changes in patients with carotid artery stenosis (CAS) after carotid artery stenting. This study was conducted as a cross-sectional, non-randomised clinical case series. Fifteen male patients (mean age: 63.6±9.1) with CAS and more than 70% carotid artery narrowing were included. All of the patients were followed in the department of neurology and were operated in the interventional radiology division. Eighteen healthy male subjects (mean age: 63.7±5.3) were included in the control group. All of the healthy subjects had a detailed ophthalmological examination and subjects with any chronic eye disease were excluded from the study. All of the participants had a detailed ophthalmological examination including tonometry using Goldmann applanation tonometry and RNFL analysis using optical coherence tomography (RTVue-100 5.1). There were no ocular ischemic symptoms in any of the participants. The mean IOP value was 15.1±2.1 mmHg in the control group and 16.6±2.4 mmHg before stent implantation, 16.4±2.2 mmHg at 1 week after implantation, 16.6±2.5 mmHg at 1 month after implantation, and 16.7±2.9 mmHg at 3 months after implantation in the CAS group. Mean RNFL thickness was 105±6 µm in the control group; in the CAS group, mean RNFL thickness values were 98±27 µm before stent implantation and 103±11 µm, 101±10 µm, and 101±11 µm at 1 week, 1 month, and 3 months after stenting. There were no significant differences between the CAS group and control group regarding IOP and RNFL thickness values (p>0.05). IOP and RNFL thickness also did not show any statistically significant changes from preoperative measurements in 3 months postoperative follow-up in the CAS group (p>0.05). IOP and RNFL thickness remained unchanged after carotid stent implantation in carotid artery stenosis patients with no signs of ocular ischemic syndrome.

Intraocular Pressure and Retinal Nerve Fibre Layer Thickness Changes After Carotid Artery Stenting

PubMed Central

Biberoğlu, Esra; Eraslan, Muhsin; Baltacıoğlu, Feyyaz; Midi, İpek

2017-01-01

Objectives: The aim of this study was to evaluate intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) changes in patients with carotid artery stenosis (CAS) after carotid artery stenting. Materials and Methods: This study was conducted as a cross-sectional, non-randomised clinical case series. Fifteen male patients (mean age: 63.6±9.1) with CAS and more than 70% carotid artery narrowing were included. All of the patients were followed in the department of neurology and were operated in the interventional radiology division. Eighteen healthy male subjects (mean age: 63.7±5.3) were included in the control group. All of the healthy subjects had a detailed ophthalmological examination and subjects with any chronic eye disease were excluded from the study. All of the participants had a detailed ophthalmological examination including tonometry using Goldmann applanation tonometry and RNFL analysis using optical coherence tomography (RTVue-100 5.1). Results: There were no ocular ischemic symptoms in any of the participants. The mean IOP value was 15.1±2.1 mmHg in the control group and 16.6±2.4 mmHg before stent implantation, 16.4±2.2 mmHg at 1 week after implantation, 16.6±2.5 mmHg at 1 month after implantation, and 16.7±2.9 mmHg at 3 months after implantation in the CAS group. Mean RNFL thickness was 105±6 µm in the control group; in the CAS group, mean RNFL thickness values were 98±27 µm before stent implantation and 103±11 µm, 101±10 µm, and 101±11 µm at 1 week, 1 month, and 3 months after stenting. There were no significant differences between the CAS group and control group regarding IOP and RNFL thickness values (p>0.05). IOP and RNFL thickness also did not show any statistically significant changes from preoperative measurements in 3 months postoperative follow-up in the CAS group (p>0.05). Conclusion: IOP and RNFL thickness remained unchanged after carotid stent implantation in carotid artery stenosis patients with no signs of ocular

Flow-independent dynamics in aneurysms: intra-aneurysm pressure measurements following complete flow cessation in internal carotid artery aneurysms.

PubMed

Qureshi, Adnan I; Qureshi, Mushtaq H; Mohindroo, Tanya; Khan, Asif A; Dingmann, Kayla; Sherr, Gregory T; Suri, M Fareed K

2014-12-01

To determine if complete flow obliteration by covered stents reduces intra-aneurysm pressures in internal carotid artery (ICA) aneurysms. A single lumen microcatheter was placed into the aneurysm sac prior to covered stent deployment in 3 patients and connected to a pressure monitoring system. The intra-aneurysm pressure was continuously monitored, and readings were recorded prior to and immediately after stent deployment and at 5-minute intervals up to 20 minutes after stent placement. Complete occlusion of flow into the aneurysms was confirmed by carotid angiography. There was no change in mean pressure within the aneurysm before and immediately after stent placement (80 mmHg) in any patient, nor was there a change in waveform of the intra-aneurysm pressure recording. The average of intra-aneurysm pressures among the 3 patients was higher (99 mmHg) at 10 and 15 minutes after stent placement. In 2 patients, the microcatheter was retracted into the parent arterial lumen; no difference in pressure was noted. Our observations suggest no change in the pressures within the aneurysm after complete flow cessation (flow-independent). These findings may assist clinicians in better understanding aneurysm hemodynamics and rupture after covered stent deployment.

Noninvasive measurement of wave speed of porcine cornea in ex vivo porcine eyes for various intraocular pressures.

PubMed

Zhou, Boran; Sit, Arthur J; Zhang, Xiaoming

2017-11-01

The objective of this study was to extend an ultrasound surface wave elastography (USWE) technique for noninvasive measurement of ocular tissue elastic properties. In particular, we aim to establish the relationship between the wave speed of cornea and the intraocular pressure (IOP). Normal ranges of IOP are between 12 and 22mmHg. Ex vivo porcine eye balls were used in this research. The porcine eye ball was supported by the gelatin phantom in a testing container. Some water was pour into the container for the ultrasound measurement. A local harmonic vibration was generated on the side of the eye ball. An ultrasound probe was used to measure the wave propagation in the cornea noninvasively. A 25 gauge butterfly needle was inserted into the vitreous humor of the eye ball under the ultrasound imaging guidance. The needle was connected to a syringe. The IOP was obtained by the water height difference between the water level in the syringe and the water level in the testing container. The IOP was adjusted between 5mmHg and 30mmHg with a 5mmHg interval. The wave speed was measured at each IOP for three frequencies of 100, 150 and 200Hz. Finite element method (FEM) was used to simulate the wave propagation in the corneal according to our experimental setup. A linear viscoelastic FEM model was used to compare the experimental data. Both the experiments and the FEM analyses showed that the wave speed of cornea increased with IOP. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing the True Intraocular Pressure in the Non-human Primate.

PubMed

McAllister, Faith; Harwerth, Ronald; Patel, Nimesh

2018-02-01

For glaucoma patients, high intraocular pressure (IOP) is a risk factor for progressive neuropathy. Similarly, animal models used to study the disease are based on an experimental elevation of IOP. Thus, accurate IOP measurements are important in characterizing experimental models and resulting effects. The purpose of the present study was to investigate IOP measurements in a non-human primate model of experimental glaucoma by comparing clinical tonometry (Tono-Pen and TonoVet) to the true IOP from intracameral manometry. A total of 17 rhesus macaque eyes from 12 animals were used for this study. Eleven eyes had no previous experimental intervention, whereas six eyes were at varying stages of laser-induced experimental glaucoma. IOPs were adjusted by inserting a needle in the anterior chamber that was attached to a pressure transducer and syringe pump system. The anterior chamber IOP was adjusted to values between 10 and 50 mmHg and corresponding measures with Tono-Pen and TonoVet were taken. The IOPs by TonoVet and Tono-Pen were linearly related over the range of pressures tested (slope = 0.68 normal/healthy and 0.72 experimental glaucoma). For the most, TonoVet measures overestimated IOP at all anterior chamber pressure settings (mean difference of 3.17 mmHg, 95% CI 12.53 to -4.74 normal and 3.90 mmHg, 95% CI 12.90 to -6.53 experimental glaucoma). In contrast, Tono-Pen measures overestimated IOP at lower IOPs and underestimated at higher IOP (slope = -0.26 normal and -0.21 experimental glaucoma). The TonoVet and Tono-Pen tonometers that are often used to assess IOP in both clinical and experimental settings generally reflect the status of IOP, but the results from this study suggest that the instruments need calibration with true anterior chamber pressure for accurate measures in experimental models of glaucoma.

Pressure-relieving properties of a intra-operative warming device.

PubMed

Baker, E A; Leaper, D J

2003-04-01

The primary objective of this study was to determine differences in interface pressure between four mattress combinations: a standard operating table mattress, a pressure-relieving gel pad and an under-patient warming device set at 38 degrees C (Pegasus Inditherm System) and at ambient temperature. The secondary objective was to determine whether the warming device remains stable in extreme surgical positions. Interface pressures obtained with all four combinations were measured in 10 healthy volunteers using force sensing array technology. The warming device demonstrated better or equivalent pressure relief when compared with the standard gel pad. There was no significant difference in subject position 'shift' between the mattress, the gel pad and the warming device for either the Trendelenberg or reverse Trendelenberg positions. Both pressure-relieving mattresses and warming reduce intra-operative pressure damage. A mattress with both properties may further reduce pressure damage postoperatively. The warming device used in this study appears stable--subject 'slippage' was minimal in extreme positions. Research needs to be conducted among real anaesthetised patients to support these conclusions.

Systemic medication and intraocular pressure in a British population: the EPIC-Norfolk Eye Study.

PubMed

Khawaja, Anthony P; Chan, Michelle P Y; Broadway, David C; Garway-Heath, David F; Luben, Robert; Yip, Jennifer L Y; Hayat, Shabina; Wareham, Nicholas J; Khaw, Kay-Tee; Foster, Paul J

2014-08-01

To determine the association between systemic medication use and intraocular pressure (IOP) in a population of older British men and women. Population-based, cross-sectional study. We included 7093 participants from the European Prospective Investigation into Cancer-Norfolk Eye Study. Exclusion criteria were a history of glaucoma therapy (medical, laser, or surgical), IOP asymmetry between eyes of >5 mmHg, and missing data for any covariables. The mean age of participants was 68 years (range, 48-92) and 56% were women. We measured IOP using the Ocular Response Analyzer. Three readings were taken per eye and the best signal value of the Goldmann-correlated IOP value considered. Participants were asked to bring all their medications and related documentation to the health examination, and these were recorded by the research nurse using an electronic case record form. The medication classes examined were angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, α-blockers, β-blockers, calcium channel blockers, diuretics, nitrates, statins, insulin, biguanides, sulfonylureas, aspirin, and other nonsteroidal anti-inflammatory drugs. We examined associations between medication use and IOP using multivariable linear regression models adjusted for age, sex, and body mass index. Models containing diabetic medication were further adjusted for glycosylated hemoglobin levels. Mean IOP of the right and left eyes. Use of systemic β-blockers (-0.92 mmHg; 95% CI, -1.19, -0.65; P<0.001) and nitrates (-0.63 mmHg; 95% CI, -1.12, -0.14; P = 0.011) were independently associated with lower IOP. The observed associations between statin or aspirin use with IOP were no longer significant after adjustment for β-blocker use. This is the first population-based study to demonstrate and quantify clinically significant differences in IOP among participants using systemic β-blockers or nitrates. Lower IOP observed in participants using statins or aspirin was explained by

The impact of arm circumference on noninvasive oscillometric blood pressure referenced with intra-aortic blood pressure.

PubMed

Shangguan, Qing; Wu, Yanqing; Xu, Jinsong; Su, Hai; Li, Juxiang; Hong, Kui; Cheng, Xiaoshu

2015-12-01

To investigate the influence of arm circumference (AC) on the brachial blood pressure (BP) measured with an adult cuff. This study included 208 patients (150 men, 61.0±8.0 years) for coronary angiography. Intra-aortic BP and noninvasive right brachial oscillometric BP (noninvasive BP) were measured simultaneously before coronary angiography. The noninvasive BP was measured using an electronic oscillometric device with an adult cuff (12×22 cm). The mid-ACs were measured. Thus, proper cuff-arm (≤26 cm) and small cuff (>26 cm) groups were created. The difference in intra-aortic and noninvasive BP was calculated as BPi-n. The correlation coefficients (r) between noninvasive and invasive systolic blood pressure (SBP), mean artery pressure, and diastolic blood pressure (DBP) were 0.88, 0.76, and 0.58, respectively. The SBPi-n was higher (7.9±1.6 vs. 5.2±1.1 mmHg), but the DBPi-n (3.9±1.4 vs. 6.1±1.0 mmHg, P<0.05) was lower in the group ≤26 cm than in the group >26 cm. Among the four subgroups divided by 20-23, 24-26, 27-30, and 31-37 cm of AC, as the AC increased, the SBPi-n increased, but DBP decreased, resulting in noninvasive SBP 4.6 mmHg higher and noninvasive DBP 4.6 mmHg lower in the 31-37 cm group in comparison with the 20-23 cm group. When an adult cuff was used, the noninvasive oscillometric SBP was overestimated, but DBP was underestimated in the individuals with large arms against the intra-aortic BP.

Ocular pharmacokinetics and tolerability of bimatoprost ophthalmic solutions administered once or twice daily in rabbits, and clinical dosing implications

PubMed Central

Shen, Jie; Goodkin, Margot L; Tong, Warren; Attar, Mayssa

2017-01-01

Purpose Fixed-combination medications can benefit patients requiring multiple agents to lower their intraocular pressure (IOP), but combining agents with complementary mechanisms of action is challenging if their dosing frequency differs. This study compares in vivo pharmacokinetic and ocular tolerability of bimatoprost 0.01% ophthalmic solutions dosed once or twice daily. Reports of twice-daily dosing in glaucoma patients are also reviewed. Methods New Zealand White rabbits were administered bimatoprost 0.01% monotherapy or fixed-combination bimatoprost 0.01%/brimonidine 0.1%, once or twice daily in both eyes for 4 days. Ocular tissues were harvested and analyzed by liquid chromatography-tandem mass spectrometry. The pharmacokinetic parameters calculated included maximum observed concentration, time to maximum concentration, and area under the concentration-time curve. Results Due to extensive metabolism, bimatoprost concentration was below the quantitation limit by 1 hour post-dose in all samples. Bimatoprost acid exposure, however, could be measured up to 6–8 hours post-dose and was similar in the aqueous humor and iris-ciliary body (pharmacological site of action) of animals treated once or twice daily with either bimatoprost 0.01% or fixed-combination bimatoprost 0.01%/brimonidine 0.1%. Increasing dosage frequency in rabbits did not raise the incidence of drug-related conjunctival hyperemia (most common adverse event associated with bimatoprost use in humans), suggesting comparable ocular tolerability of the once- and twice-daily regimens for each formulation. Conclusion Bimatoprost 0.01% administered once or twice daily as monotherapy and in fixed-combination with brimonidine 0.1% in rabbits show similar pharmacokinetic profiles of bimatoprost acid, especially in the iris-ciliary body. Key findings from previous clinical studies suggest that by varying the concentration of benzalkonium chloride (a preservative with corneal penetration-enhancing properties

Ethnic differences of intraocular pressure and central corneal thickness: the Singapore Epidemiology of Eye Diseases study.

PubMed

Chua, Jacqueline; Tham, Yih Chung; Liao, Jiemin; Zheng, Yingfeng; Aung, Tin; Wong, Tien Yin; Cheng, Ching-Yu

2014-10-01

To determine the ethnic differences in the distribution of intraocular pressure (IOP) and central corneal thickness (CCT) in a multi-ethnic Asian population by self-reported ethnicity and genetic ancestry. Population-based, cross-sectional study. A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years. Participants underwent standardized systemic and ocular examinations and interviewer-administered questionnaires for risk factor assessment. The IOP readings were obtained by Goldmann applanation tonometry (Haag-Streit, Konig, Switzerland) before pupil dilation. The CCT was measured with ultrasound pachymetry. Genetic ancestry was derived using principal component (PC) analysis. Regression models were used to investigate the association of IOP and CCT with potential risk factors and genetic ancestry. Intraocular pressure and CCT. After excluding participants with a history of glaucoma surgery or medication, refractive surgery, corneal edema, or corneal dystrophy, IOP and CCT readings were available for 3251 Chinese, 3232 Malays, and 3317 Indians. The mean IOP readings in the Chinese, Malay, and Indian participants were 14.3±3.1, 15.3±3.7, and 15.8±2.9 mmHg, respectively (P < 0.001). The prevalence of participants with IOP ≥21 mmHg was 2.6% in Chinese, 6.2% in Malays, and 4% in Indians (P < 0.001). In the multivariate regression analysis, the Malay and Indian participants on average had 0.81 and 1.43 mmHg higher IOP levels, respectively, than Chinese (P < 0.001). The mean CCT reading was 552.3±33.4 μm in Chinese, 540.9±33.6 μm in Malays, and 540.4±33.6 μm in Indians (P < 0.001). The percentage of participants with CCT <555 μm was 52.8% in Chinese, 68.5% in Malays, and 66.2% in Indians (P < 0.001). The IOP and CCT levels are significantly correlated with genetic ancestry in our South East Asian population. Chinese have the thickest CCT but lowest IOP among the 3 major ethnic groups. In addition, there is a

24-Hour Efficacy and Ocular Surface Health with Preservative-Free Tafluprost Alone and in Conjunction with Preservative-Free Dorzolamide/Timolol Fixed Combination in Open-Angle Glaucoma Patients Insufficiently Controlled with Preserved Latanoprost Monotherapy.

PubMed

Konstas, Anastasios-Georgios; Boboridis, Konstadinos G; Kapis, Paraskevas; Marinopoulos, Konstantinos; Voudouragkaki, Irini C; Panayiotou, Dimitrios; Mikropoulos, Dimitrios G; Pagkalidou, Eirini; Haidich, Anna-Bettina; Katsanos, Andreas; Quaranta, Luciano

2017-01-01

The aim of the present study was to evaluate the 24-h efficacy, tolerability, and ocular surface health with preservative-free (PF) tafluprost and a PF triple drug regimen comprising tafluprost and dorzolamide/timolol fixed combination (DTFC) in open-angle glaucoma patients who were insufficiently controlled with preserved branded or generic latanoprost monotherapy and who exhibited signs or symptoms of ocular surface disease (OSD). Prospective, observer-masked, crossover, comparison. Eligible consecutive open-angle glaucoma patients were randomized to either PF tafluprost or the triple PF regimen for 3 months. They were then crossed over to the opposite therapy for another 3 months. At the end of the latanoprost run-in period and after each PF treatment period, patients underwent habitual 24-h intraocular pressure (IOP) monitoring with Goldmann tonometry in the sitting position (at 10:00, 14:00, 18:00, and 22:00) and Perkins tonometry in the supine position (at 02:00 and 06:00). Tolerability and selected ocular surface parameters were evaluated at baseline and the end of each treatment period. Forty-three open-angle glaucoma patients completed the trial. Mean 24-h IOP on preserved latanoprost was 22.2 ± 3.9 mmHg. Compared with latanoprost monotherapy, PF tafluprost obtained a greater reduction in mean, peak, and fluctuation of 24-h IOP including the 02:00 and 06:00 time points (P < 0.05). With the exception of 24-h fluctuation, the triple PF regimen provided significantly lower IOP parameters than latanoprost or PF tafluprost (P < 0.001). Finally, PF tafluprost therapy displayed significantly improved tear film break-up times (6.7 vs 6.0 s), corneal staining (1.3 vs 2.2), and Schirmer I test results (9.1 vs 8.2 mm) compared with the preserved latanoprost baseline (all P < 0.01). The triple PF regimen demonstrated similar tear film break-up times (6.1 vs 6.0 s) and Schirmer I test results (8.2 vs 8.2 mm) to latanoprost, but revealed a significant

Outcomes and Complications of Ahmed Tube Implantation in Asian Eyes.

PubMed

Choo, Jessica Qian Hui; Chen, Ziyou David; Koh, Victor; Liang, Shen; Aquino, Cecilia Maria; Sng, Chelvin; Chew, Paul

2018-06-18

There is a lack of long-term Asian studies on the efficacy and safety of Ahmed glaucoma valve (AGV) implantation. This study seeks to determine the outcomes and complications of AGV implantation in Asians. Retrospective review of AGV surgeries performed at a single centre in Singapore was conducted. 76 patients with primary and secondary glaucoma who underwent their first AGV surgery from 1st January 2010 to 31st December 2012 were considered for our study. Primary outcomes evaluated were: failure, intra-ocular pressure, best-corrected visual acuity (BCVA), number of IOP-lowering medications and complications. Failure was defined by: IOP >21▒mm Hg on two consecutive visits after 3 months, IOP ≤5▒mm Hg on two consecutive visits after 3 months, reoperation for glaucoma, removal of implant or loss of light perception vision. Mean follow-up duration was 33.2±6.9 months. There was significant reduction in IOP (mean reduction 25.9%, P<0.001) and number of IOP-lowering medications (mean reduction 77.8%, P<0.001) at 3 years. Absolute failure rate was 23.9% at 3 years with no difference between eyes with or without previous trabeculectomy and between eyes with primary or secondary glaucoma. Occurrence of post-operative hyphema was a significant risk factor for failure. Commonest post-operative complications were hyphema and tube exposure. At 3 years after AGV surgery in Asian eyes, less than one-quarter of the eyes fulfilled the criteria for surgical failure.

INTRAOCULAR PRESSURE AND EXAMINATION FINDINGS IN THREE SPECIES OF CENTRAL AND SOUTH AMERICAN TREE FROGS (CRUZIOHYLA CRASPEDOPUS, CRUZIOHYLA CALCARIFER, AND ANOTHECA SPINOSA).

PubMed

Lewin, Andrew C; Hausmann, Jennifer C; Miller, Paul E

2017-09-01

The purpose of this prospective study was to describe intraocular pressure (IOP) and examination findings in three tree frog species (Cruziohyla craspedopus [fringe leaf frog], Cruziohyla calcarifer [splendid leaf frog], and Anotheca spinosa [spiny-headed or coronated tree frog]). Thirty-one C. craspedopus, four C. calcarifer, and five A. spinosa were weighed, sexed based on phenotype where possible, and examined using slit-lamp biomicroscopy and indirect ophthalmoscopy. IOP was measured using the TonoVet and TonoLab rebound tonometers while the frogs were held two ways (unrestrained, then restrained). Statistical differences were determined using one-way analysis of variance (ANOVA) and t-tests. Mean ± SD IOP (TonoVet and TonoLab, respectively) was 15.1 ± 2.5 mmHg and 15.6 ± 4.1 mmHg in C. craspedopus; 14.8 ± 1.5 mmHg and 18.8 ± 3.1 mmHg in C. calcarifer; and 9.1 ± 2.1 mmHg and 10.8 ± 1.4 mmHg in A. spinosa. There was no significant difference in IOP in C. craspedopus by eye (Right vs Left), tonometer, or restraint method. IOP in female C. craspedopus was 1-3 mm Hg higher than in males with both devices (P < 0.05). IOP was statistically significantly different between all species for the TonoLab and between Cruziohyla genus frogs and A. spinosa for the TonoVet (P < 0.05). There was no difference in IOP measurements between the TonoVet and TonoLab in C. craspedopus. IOP varied by gender in C. craspedopus and between species, but not by tonometer. Ocular abnormalities were minimal in this group of captive bred frogs.

Intraocular pressure, ultrasonographic and echobiometric findings of juvenile Yacare caiman (Caiman yacare) eye.

PubMed

Ruiz, Thaís; Campos, Wilma N S; Peres, Thalita P S; Gonçalves, Gentil F; Ferraz, Rosa H S; Néspoli, Pedro E B; Sousa, Valéria R F; Ribeiro, Alexandre P

2015-01-01

The aim was to determine the intraocular pressure (IOP), the ultrasonographic and echobiometric findings in the eyes of juvenile Yacare caiman (Caiman yacare). Twenty-two healthy caimans from a breeding farm in Brazilian Pantanal. Intraocular pressure was measured under physical restraint and topical anesthesia by applanation tonometry. Five individual measurements of each eye were recorded by the same examiner. B-mode ultrasonography was performed with a 10-MHz linear transducer, and the anterior chamber depth, lens thickness, vitreous depth, and axial globe length were measured. Unpaired and paired t-tests were used to assess data. Pearson's test was used to assess correlations between IOP and ocular structures (P < 0.05). Mean ± SD IOP of the 44 eyes studied was 9.56 ± 2.69 mmHg, (range 5.4-15.6 mmHg). IOP did not differ significantly between right and left eyes or between genders (P > 0.05). Echobiometric measurements did not differ significantly between eyes and genders (P > 0.05). Intraocular structures measured in male and female subjects were, respectively, 2.61 ± 0.13 and 2.55 ± 0.18 mm for anterior chamber depth, 7.60 ± 0.17 and 7.54 ± 0.20 mm for lens thickness, 6.83 ± 0.20 and 6.90 ± 0.22 mm for vitreous chamber depth, and 17.55 ± 0.25 and 17.54 ± 0.29 mm for axial globe length. Correlations were not observed (P > 0.05). Reference values of tonometry and distances of intraocular structures of Yacare caiman were described. IOP did not correlate with echobiometric measurements in this crocodilian. The ultrasonographic appearance was similar to other domestic and wild species. © 2014 American College of Veterinary Ophthalmologists.

The efficacy and safety of bimatoprost/timolol maleate, latanoprost/timolol maleate, and travoprost/timolol maleate fixed combinations on 24-h IOP.

PubMed

Guven Yilmaz, Suzan; Degirmenci, Cumali; Karakoyun, Yunus Emre; Yusifov, Emil; Ates, Halil

2017-06-14

To evaluate the effect of bimatoprost/timolol maleate fixed combination (BTFC), latanoprost/timolol maleate fixed combination (LTFC), and travoprost/timolol maleate fixed combination (TTFC) on 24-h intraocular pressure (IOP) in patients with open-angle glaucoma. This prospective, observer-masked, randomized study included 50 patients with primary open-angle glaucoma. All patients were using hypotensive lipids and timolol maleate fixed combination treatment for ≥4 weeks and had an IOP ≤ 21 mmHg. Group 1 (n = 18) received BTFC, group 2 (n = 14) received LTFC, and group 3 (n = 18) received TTFC. All patients were hospitalized, and IOP was monitored for 24-h (10:00, 14:00, 18:00, 22:00, 02:00, and 06:00). Mean diurnal IOP variation measurements were taken between 06:00 and 18:00, and mean nocturnal IOP variation measurements were taken between 22:00 and 02:00. Mean IOP and IOP variation in the three groups were compared. Mean 24-h IOP did not differ significantly between the three groups (group 1: 14.6 ± 2.9 mmHg; group 2: 14.1 ± 3.7 mmHg and group 3: 15.8 ± 2.0 mmHg; P > 0.05). Mean diurnal IOP variation was 4.6 ± 2.3 mmHg in group 1, 5.8 ± 2.4 mmHg in group 2, and 4.3 ± 1.7 mmHg in group 3, and mean nocturnal IOP variation was 3.2 ± 2.8 mmHg in group 1, 2.9 ± 1.9 mmHg in group 2, and 3.0 ± 1.6 mmHg group 3. There were not any significant differences in diurnal or nocturnal IOP variation between the three groups (P < 0.05). All three fixed combinations effectively controlled IOP for 24-h and had a similar effect on diurnal and nocturnal IOP variations.

Systematic Occlusion of Shunts: Control of Early Postoperative IOP and Hypotony-related Complications Following Glaucoma Shunt Surgery.

PubMed

Sharkawi, Eamon; Artes, Paul H; Oleszczuk, Justyna D; Bela, Cyrielle; Achache, Farid; Barton, Keith; Bergin, Ciara

2016-01-01

Evaluation of a protocol of total intraluminal occlusion of Baerveldt shunts and its effects on early postoperative intraocular pressure (IOP) control and hypotony-related complications. This was a noncomparative, prospective, and interventional study. Glaucoma patients were recruited to undergo Baerveldt shunt surgery. A total of 116 eyes of 112 patients were enrolled. During shunt implantation, aqueous outflow was restricted using an intraluminal occluding stent inserted through the entire tube length, with and without external ligation, to halt aqueous flow. Postoperatively, eyes underwent ligature laser suture lysis and partial or complete stent removals, at predetermined time intervals. Loss of postoperative IOP control was categorized as transient or persistent hypotony (IOP≤5 mm Hg) or hypertony (IOP>21 mm Hg). Patients were followed up for 1 year. Preoperatively median IOP was 23 mm Hg (mean 26 mm Hg, SD 12 mm Hg), median number of glaucoma medications was 3.0 (mean 3.0, SD 1.2). During year 1, laser suture lysis was performed in 30 eyes (26%) and stent removal in 93 eyes (80%) (23 partial; 70 complete). There was 1 case of transient hypotony, no cases of persistent hypotony, 10 of transient hypertony, and 3 of persistent hypertony. Nine eyes had IOP≤5 mm Hg at ≥1 time points and hypotony-related complications occurred in 8 eyes (7%). At 1 year, median IOP was 12 mm Hg (mean 13 mm Hg, SD 4 mm Hg) with a median of 1.0 glaucoma medications (mean 1.1, SD 1.3). The cumulative probability of failure during the first 12 months follow-up was 6% (n=7). Overall postoperative complications occurred in 11 eyes (9%). The surgical and postoperative protocol resulted in controlled, step-wise reductions of IOP with low rates of hypotony and related complications.

Meta-analysis of the Efficacy and Safety of Latanoprost Monotherapy in Patients With Angle-closure Glaucoma.

PubMed

Chen, Ru; Yang, Ke; Zheng, Zhong; Ong, Moh-Lim; Wang, Ning-Li; Zhan, Si-Yan

2016-03-01

To systematically evaluate the safety and efficacy of latanoprost monotherapy for the treatment of patients with angle-closure glaucoma. We searched EMBASE, Medline, Cochrane Library, Chinese Journal Full-text Database (CNKI), Chinese Science and Technology Periodical Database (VIP), and Wang Fang using the search terms "latanoprost" (or its commercial name, Xalatan) and "angle-closure glaucoma." Resulting articles were then screened using preset inclusion criteria. Subgroup and sensitivity analyses were performed to evaluate the impact of research population, research type (blinded or controlled), and withdrawal/loss to follow-up. A total of 17 studies (n=807) were included in this meta-analysis. The primary outcome measure was intraocular pressure (IOP). Changes in the mean, peak, and trough IOP from baseline were used as effect measures. As I statistic revealed statistical heterogeneity, the random-effects model was applied. With the exception of 2 non-Asian populations from Australia and Peru, all 13 countries included in this study were from Asia. Latanoprost reduced mean IOP by 7.9 mm Hg (32.4%), peak IOP by 7.4 mm Hg (29.8%), and trough IOP by 7.9 mm Hg (32.5%). The most frequent ocular adverse effects were ocular hyperemia, discomfort (including eye irritation, ocular discomfort, foreign body sensation, and itching), and blurred vision with a total incidence rate of 9.4%, 8.7%, and 5.2%, respectively. Systemic adverse effects encompass rhinitis, dizziness, headache, and nonspecific skin pigmentation. Latanoprost is effective at reducing the IOP of patients with angle-closure glaucoma. Adverse reactions associated with latanoprost were mainly ocular in nature.

Sodium Orthovanadate Effect on Outflow Facility and Intraocular Pressure in Live Monkeys

PubMed Central

Tan, James C.H.; Kiland, Julie A.; Gonzalez, Jose M.; Gabelt, B’Ann T.; Peters, Donna M.; Kaufman, Paul L.

2010-01-01

occurred within 24 hours after Na3VO4-containing culture medium was replaced with Na3VO4-free medium. Ocular administration of Na3VO4 to live monkeys significantly increases OF and reduces IOP. Na3VO4 reversibly disrupts actin and cell adhesion organization and causes retraction and separation of cultured HTM cells. Na3VO4 increases pressure-dependent outflow in live monkeys. Altered actin architecture in the TM may play a part in this increased OF. PMID:20620138

Wireless system for monitoring Intra-abdominal pressure in patient with severe abdominal pathology

NASA Astrophysics Data System (ADS)

Sokolovskiy, S. S.; Shtotskiy, Y. V.; Leljanov, A. D.

2017-01-01

The paper discusses an experimental design of the wireless system for monitoring intra-abdominal pressure (IAP) using Bluetooth Low Energy technology. The possibility of measuring IAP via the bladder using a wireless pressure sensor with a hydrophobic bacteria filter between the liquid transmitting medium and the sensor element is grounded.

Intraocular Pressure Changes With Positioning During Laparoscopy

PubMed Central

Onakpoya, Oluwatoyin H.; Adenekan, Anthony T.; Awe, Oluwaseun. O.

2016-01-01

Background and Objectives: Pneumoperitoneum during laparoscopy can produce changes in intraocular pressure (IOP) that may be influenced by several factors. In this study, we investigated changes in IOP during laparoscopy with different positioning. Methods: We recruited adult patients without eye disease scheduled to undergo laparoscopic operation requiring a reverse Trendelenburg tilt (rTr; group A; n = 20) or Trendelenburg tilt (Tr; Group B; n = 20). IOP was measured at 7 time points (T1–T7). All procedures were performed with standardized anaesthetic protocol. Mean arterial pressure (MAP), heart rate (HR), peak and plateau airway pressure, and end-tidal carbon dioxide (ETCO2) measurements were taken at each time point. Results: Both groups were similar in age, sex, mean body mass index (BMI), duration of surgery, and preoperative IOP. A decrease in IOP was observed in both groups after induction of anaesthesia (T2), whereas induction of pneumoperitoneum produced a mild increase in IOP (T3) in both groups. The Trendelenburg tilt produced IOP elevations in 80% of patients compared to 45% after the reverse Trendelenburg tilt (P = .012). A significant IOP increase of 5 mm Hg or more was recorded in 3 (15%) patients in the Trendelenburg tilt group and in none in the reverse Trendelenburg group. At T7, IOP had returned to preoperative levels in all but 3 (15%) in the Trendelenburg and 1 (5%) in the reverse Trendelenburg group. Reversible changes were observed in the MAP, HR, ETCO2, and airway pressures in both groups. Conclusions: IOP changes induced by laparoscopy are realigned after evacuation of pneumoperitoneum. A Trendelenburg tilt however produced significant changes that may require careful patient monitoring during laparoscopic procedures. PMID:28028381

Preservative-free tafluprost 0.0015% in the treatment of patients with glaucoma and ocular hypertension.

PubMed

Erb, Carl; Lanzl, Ines; Seidova, Seid-Fatima; Kimmich, Friedemann

2011-07-01

The objective of this study was to evaluate efficacy, local tolerability, and safety of this first-in-class preservative-free prostaglandin preparation in patients with ocular hypertension and glaucoma. Patients with glaucoma or ocular hypertension who required a change of medication or were naïve to treatment were included in this noninterventional and observational study. Noninterventional means that no influence was made upon the decision of the physicians to include specific patients and upon the treatment algorithm used. German law for observational studies does not allow any influence on the choice of drugs used, patient selection, masking, and comparator treatment regimens. The main aim of this observational study was to collect "real-life data" on the efficacy and safety of a new medical treatment after approval in a large patient population. Participating ophthalmologists were asked to provide anonymous patient data collected during regular visits by filling a simple data entry form. Intraocular pressure (IOP) readings were recorded at baseline (previous therapy or untreated) and 6-12 weeks after changing medical treatment to or initiating treatment with preservative-free tafluprost once daily. Changes in the IOP were evaluated over the study period for all patients as well as for specific pretreatment subgroups. Local comfort was determined using a five-point scale (very good, good, satisfactory, less satisfactory, not acceptable) before and after the change of medical treatment. All adverse events were recorded. Data from 2123 patients with glaucoma or ocular hypertension were considered for the final evaluation. Medication was changed in 41.1% of patients due to tolerability issues and in 25.6% of patients due to insufficient efficacy with prior medication. In all patients preservative-free tafluprost 0.0015% lowered IOP from 19.5 ± 4.4 mmHg (baseline) to 16.4 ± 2.9 mmHg after 6-12 weeks. Preservativefree tafluprost also significantly lowered the IOP

Differences in ocular parameters between diurnal and nocturnal raptors.

PubMed

Beckwith-Cohen, Billie; Horowitz, Igal; Bdolah-Abram, Tali; Lublin, Avishai; Ofri, Ron

2015-01-01

To establish and compare normal ocular parameters between and within diurnal and nocturnal raptor groups. Eighty-eight ophthalmically normal raptors of six nocturnal and 11 diurnal species were studied. Tear production was measured using Schirmer tear test (STT) and phenol red thread test (PRTT), and applanation tonometry was conducted. Ultrasonographic measurements of axial length (AL), mediolateral axis (ML), vitreous body (VB), and pecten length (PL) were recorded, and conjunctival cultures were obtained. A weak correlation (R = 0.312, P = 0.006) was found between PRTT and STT. Tear production was significantly lower in nocturnal species (P < 0.001), but no difference was observed in intraocular pressure (IOP). VB and PL were significantly longer in diurnals (P < 0.001 and P = 0.021, respectively), and no significant difference was observed in AL and ML. When comparing results within these groups, there was a significant difference between most species for all parameters except IOP. Fifty-one percent of the examined raptors were positive for mycology or bacteriology, either on culture or PCR. The most common infectious agent isolated was Staphylococcus spp. Phenol red thread test and STT are both valid methods to measure tear production; however, a separate baseline must be determined for each species using these methods, as the results of one method cannot be extrapolated to the other. Due to significant differences observed within diurnal and nocturnal species, it appears that a more intricate division should be used when comparing these parameters for raptors, and the classification of diurnal or nocturnal holds little significance in the baseline of these data. © 2013 American College of Veterinary Ophthalmologists.

Effects of morphine-alfaxalone-midazolam premedication, alfaxalone induction and sevoflurane maintenance on intraocular pressure and tear production in dogs.

PubMed

Mayordomo-Febrer, A; Rubio, M; Martínez-Gassent, M; López-Murcia, M M

2017-05-13

Intraocular pressure (IOP) and tear production are commonly affected by general anaesthesia. It is necessary to have a good control of both to guarantee successful ophthalmic surgery. The purpose of this research was to evaluate if the protocol based on the administration of morphine-alfaxalone-midazolam as premedication, alfaxalone as induction and sevoflurane as maintenance, can induce changes on IOP and Schirmer's tear test (STT-1) in healthy dogs. Twenty-two adult mixed-breed dogs scheduled for an ovariohysterectomy were enrolled for the study. IOP and STT-1 were registered at baseline (T 0 ), 5 minutes (T 1 ), 10 minutes (T 2 ) and 15 minutes (T 3 ) after premedication with a morphine-alfaxalone-midazolam combination; 5 minutes (T 4 ) after induction with alfaxalone and 15 minutes (T 5 ) and 25 minutes (T 6 ) after maintenance with sevoflurane. A one-way analysis of variance was performed to analyse the difference between IOP and STT-1 over time, respectively. The present study shows a slightly statistically significant increase in IOP (P<0.05) after premedication, induction and maintenance that can be associated with this anaesthetic protocol. STT-1 showed a statistically significant reduction during all the procedures (P<0.001). These results should be taken into consideration, especially in dogs with damaged corneas, in those predisposed to glaucoma and in those due to undergo intraocular surgery. Ocular lubrication is necessary if this protocol is used. British Veterinary Association.

Protocol-driven adjustment of ocular hypotensive medication in patients at low risk of conversion to glaucoma.

PubMed

Chan, Poemen P M; Leung, Christopher K S; Chiu, Vivian; Gangwani, Rita; Sharma, Abhishek; So, Sophie; Congdon, Nathan

2015-09-01

To investigate the safety and potential savings of decreasing medication use in low-risk patients with ocular hypertension (OH). Patients with OH receiving pressure-lowering medication identified by medical record review at a university hospital underwent examination by a glaucoma specialist with assessment of visual field (VF), vertical cup-to-disc ratio (vCDR), central corneal thickness and intraocular pressure (IOP). Subjects with estimated 5-year risk of glaucoma conversion <15% were asked to discontinue ≥1 medication, IOP was remeasured 1 month later and risk was re-evaluated at 1 year. Among 212 eyes of 126 patients, 44 (20.8%) had 5-year risk >15% and 14 (6.6%) had unreliable baseline VF. At 1 month, 15 patients (29 eyes, 13.7%) defaulted follow-up or refused to discontinue medication and 11 eyes (5.2%) had risk >15%. The remaining 69 patients (107 eyes, 50.7%) successfully discontinued 141 medications and completed 1-year follow-up. Mean IOP (20.5±2.65 mm Hg vs 20.3±3.40, p=0.397) did not change, though mean VF pattern SD (1.58±0.41 dB vs 1.75±0.56 dB, p=0.001) and glaucoma conversion risk (7.31±3.74% vs 8.76±6.28%, p=0.001) increased at 1 year. Mean defect decreased (-1.42±1.60 vs -1.07±1.52, p=0.022). One eye (0.47%) developed a repeatable VF defect and 13 eyes (6.1%) had 5-year risk >15% at 1 year. The total 1-year cost of medications saved was US$4596. Nearly half (43.9%) of low-risk OH eyes in this setting could safely reduce medications over 1 year, realising substantial savings. 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.

Extracellular vesicles mediate signaling between the aqueous humor producing and draining cells in the ocular system

PubMed Central

Lerner, Natalie; Avissar, Sofia

2017-01-01

Purpose Canonical Wnt signaling is associated with glaucoma pathogenesis and intraocular pressure (IOP) regulation. Our goal was to gain insight into the influence of non-pigmented ciliary epithelium (NPCE)-derived exosomes on Wnt signaling by trabecular meshwork (TM) cells. The potential impact of exosomes on Wnt signaling in the ocular drainage system remains poorly understood. Methods Exosomes isolated from media collected from cultured NPCE cells by differential ultracentrifugation were characterized by dynamic light scattering (DLS), tunable resistive pulse sensing (TRPS), and nanoparticle tracking analysis (NTA), sucrose density gradient migration and transmission electron microscopy (TEM). The cellular target specificity of the NPCE-derived exosomes was investigated by confocal microscopy-based monitoring of the uptake of DiD-labeled exosomes over time, as compared to uptake by various cell lines. Changes in Wnt protein levels in TM cells induced by NPCE exosomes were evaluated by Western blot. Results Exosomes derived from NPCE cells were purified and detected as small rounded 50–140 nm membrane vesicles, as defined by DLS, NTA, TRPS and TEM. Western blot analysis indicated that the nanovesicles were positive for classic exosome markers, including Tsg101 and Alix. Isolated nanoparticles were found in sucrose density fractions typical of exosomes (1.118–1.188 g/mL sucrose). Using confocal microscopy, we demonstrated time-dependent specific accumulation of the NPCE-derived exosomes in NTM cells. Other cell lines investigated hardly revealed any exosome uptake. We further showed that exosomes induced changes in Wnt signaling protein expression in the TM cells. Western blot analysis further revealed decreased phosphorylation of GKS3β and reduced β-catenin levels. Finally, we found that treatment of NTM cells with exosomes resulted in a greater than 2-fold decrease in the level of β-catenin in the cytosolic fraction. In contrast, no remarkable difference

Extracellular vesicles mediate signaling between the aqueous humor producing and draining cells in the ocular system.

PubMed

Lerner, Natalie; Avissar, Sofia; Beit-Yannai, Elie

2017-01-01

Canonical Wnt signaling is associated with glaucoma pathogenesis and intraocular pressure (IOP) regulation. Our goal was to gain insight into the influence of non-pigmented ciliary epithelium (NPCE)-derived exosomes on Wnt signaling by trabecular meshwork (TM) cells. The potential impact of exosomes on Wnt signaling in the ocular drainage system remains poorly understood. Exosomes isolated from media collected from cultured NPCE cells by differential ultracentrifugation were characterized by dynamic light scattering (DLS), tunable resistive pulse sensing (TRPS), and nanoparticle tracking analysis (NTA), sucrose density gradient migration and transmission electron microscopy (TEM). The cellular target specificity of the NPCE-derived exosomes was investigated by confocal microscopy-based monitoring of the uptake of DiD-labeled exosomes over time, as compared to uptake by various cell lines. Changes in Wnt protein levels in TM cells induced by NPCE exosomes were evaluated by Western blot. Exosomes derived from NPCE cells were purified and detected as small rounded 50-140 nm membrane vesicles, as defined by DLS, NTA, TRPS and TEM. Western blot analysis indicated that the nanovesicles were positive for classic exosome markers, including Tsg101 and Alix. Isolated nanoparticles were found in sucrose density fractions typical of exosomes (1.118-1.188 g/mL sucrose). Using confocal microscopy, we demonstrated time-dependent specific accumulation of the NPCE-derived exosomes in NTM cells. Other cell lines investigated hardly revealed any exosome uptake. We further showed that exosomes induced changes in Wnt signaling protein expression in the TM cells. Western blot analysis further revealed decreased phosphorylation of GKS3β and reduced β-catenin levels. Finally, we found that treatment of NTM cells with exosomes resulted in a greater than 2-fold decrease in the level of β-catenin in the cytosolic fraction. In contrast, no remarkable difference in the amount of �

Plasma rich in growth factors membrane as coadjuvant treatment in the surgery of ocular surface disorders.

PubMed

Sanchez-Avila, Ronald M; Merayo-Lloves, Jesús; Riestra, Ana C; Berisa, Silvia; Lisa, Carlos; Sánchez, José Alfonso; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

2018-04-01

To evaluate the safety and efficacy of the surgical use of plasma rich in growth factors fibrin membrane (mPRGF) in different ocular surface pathologies.Fifteen patients with different corneal and conjunctival diseases were included in the study. Patients were grouped according to the use of mPRGF as graft (corneal and/or conjunctival) or dressing; they were also grouped according to the surgical subgroup of intervention (persistent corneal ulcer [PCU], keratoplasty, superficial keratectomy, corneal perforation, and pterygium). Best corrected visual acuity, intraocular pressure (IOP), inflammation control time (ICT), mPRGF AT (PRGF membrane absorption time), and the healing time of the epithelial defect (HTED) were evaluated throughout the clinical follow-up time. Safety assessment was also performed reporting all adverse events.mPRGF showed a total closure of the defect in 13 of 15 patients (86.7%) and a partial closure in 2 patients (13.3%). The mean follow-up time was 11.1 ± 4.2 (4.8-22.8) months, the mean ICT was 2.5 ± 1.1 (1.0-4.0) months, the mean mPRGF AT was 12.4 ± 2.0 (10.0-16.0) days, and for the global HTED the mean was 2.9 ± 1.2 (1-4.8) months. Results showed an improvement in BCVA in all patients, with an overall improvement of 2.9 in Vision Lines. The BCVA significantly improved (P < .05) in the groups of corneal graft and dressing. In the PCU subgroup (6 patients), the healing time of epithelial defect was significantly reduced (P < .05) in patients treated only with the mPRGF in comparison to those which mPRGF therapy was associated to the amniotic membrane. The IOP remained stable (P > .05) throughout the clinical follow-up time. No adverse events were reported after mPRGF use.The mPRGF is effective and safe as coadjuvant treatment in surgeries related with ocular surface disorders, being an alternative to the use of amniotic membrane. The mPRGF accelerates tissue regeneration after ocular surface surgery thus

Effects of water drinking test on ocular blood flow waveform parameters: A laser speckle flowgraphy study.

PubMed

Bhatti, Mehwish Saba; Tang, Tong Boon; Laude, Augustinus

2017-01-01

The water-drinking test (WDT) is a provocative test used in glaucoma research to assess the effects of elevated intraocular pressure (IOP). Defective autoregulation due to changes in perfusion pressure may play a role in the pathophysiology of several ocular diseases. This study aims to examine the effects of WDT on ocular blood flow (in the form of pulse waveform parameters obtained using laser speckle flowgraphy) to gain insight into the physiology of ocular blood flow and its autoregulation in healthy individuals. Changes in pulse waveform parameters of mean blur rate (MBR) in the entire optic nerve head (ONH), the vasculature of the ONH, the tissue area of the ONH, and the avascular tissue area located outside of the ONH were monitored over time. Significant increases in the falling rate of MBR over the entire ONH and its tissue area and decreases in blowout time (BOT) of the tissue area were observed only at 10 minutes after water intake. Significant increases in the skew of the waveform and the falling rate were observed in the vasculature of the ONH at 40 and 50 minutes after water intake, respectively. In the avascular region of the choroid, the average MBR increased significantly up to 30 minutes after water intake. Furthermore, the rising rate in this region increased significantly at 20 and 40 minutes, and the falling rate and acceleration-time index were both significantly increased at 40 minutes after water intake. Our results indicate the presence of effective autoregulation of blood flow at the ONH after WDT. However, in the choroidal region, outside of the ONH, effective autoregulation was not observed until 30 minutes after water intake in healthy study participants. These pulse waveform parameters could potentially be used in the diagnosis and/or monitoring of patients with glaucoma.

Effects of water drinking test on ocular blood flow waveform parameters: A laser speckle flowgraphy study

PubMed Central

Bhatti, Mehwish Saba; Laude, Augustinus

2017-01-01

The water-drinking test (WDT) is a provocative test used in glaucoma research to assess the effects of elevated intraocular pressure (IOP). Defective autoregulation due to changes in perfusion pressure may play a role in the pathophysiology of several ocular diseases. This study aims to examine the effects of WDT on ocular blood flow (in the form of pulse waveform parameters obtained using laser speckle flowgraphy) to gain insight into the physiology of ocular blood flow and its autoregulation in healthy individuals. Changes in pulse waveform parameters of mean blur rate (MBR) in the entire optic nerve head (ONH), the vasculature of the ONH, the tissue area of the ONH, and the avascular tissue area located outside of the ONH were monitored over time. Significant increases in the falling rate of MBR over the entire ONH and its tissue area and decreases in blowout time (BOT) of the tissue area were observed only at 10 minutes after water intake. Significant increases in the skew of the waveform and the falling rate were observed in the vasculature of the ONH at 40 and 50 minutes after water intake, respectively. In the avascular region of the choroid, the average MBR increased significantly up to 30 minutes after water intake. Furthermore, the rising rate in this region increased significantly at 20 and 40 minutes, and the falling rate and acceleration-time index were both significantly increased at 40 minutes after water intake. Our results indicate the presence of effective autoregulation of blood flow at the ONH after WDT. However, in the choroidal region, outside of the ONH, effective autoregulation was not observed until 30 minutes after water intake in healthy study participants. These pulse waveform parameters could potentially be used in the diagnosis and/or monitoring of patients with glaucoma. PMID:28742142

Axonal/Glial Upregulation of EphB/ephrin-B Signaling in Mouse Experimental Ocular Hypertension

PubMed Central

Tran, Tony; Sretavan, David

2010-01-01

Purpose. To use a laser-induced ocular hypertension (LIOH) mouse model to examine the optic nerve head (ONH) expression of EphB/ephrin-B, previously shown to be upregulated in glaucomatous DBA/2J mice. To relate ephrin-B reverse signaling with states of axonal response to disease. Methods. LIOH was induced unilaterally in CD-1 mice by laser photocoagulation of limbal and episcleral veins. Intraocular pressure (IOP) was measured with a tonometer. EphB/ephrin-B mRNA expression was assessed by in situ hybridization on eyecup cryosections and real-time PCR. Cell specific markers were used to identify the cellular origin of EphB/ephrin-B expression. Activation of ephrin-B signaling was investigated with a phosphospecific antibody on cryosections and retinal whole-mounts. Results. Upregulation of EphB/ephrin-B expression occurred early within a day of IOP elevation. A transient increase of phosphorylation-dependent ephrin-B (pEB) reverse signaling was observed in ONH axons, microglia, and some astrocytes. Morphologically unaffected retinal ganglion cell (RGC) axons differed from axons with reactive aberrant trajectories by exhibiting increased pEB activation, whereas pEB levels in morphologically affected axons were comparable to those of controls. Conclusions. An Eph-ephrin signaling network is activated at the ONH after LIOH in CD-1 mice, either before or coincident with the initial morphologic signs of RGC axon damage reported previously. Of note, ephrin-B reverse signaling was transiently upregulated in RGC axons at the ONH early in their response to IOP elevation but was downregulated in axons that had been damaged by glaucomatous injury and exhibited aberrant trajectories. Ephrin-B reverse signaling may mark RGC axons for damage or confer a protective advantage against injury. PMID:19815726

Modulation of matrix metalloproteinase activity by EDTA prevents posterior capsular opacification

PubMed Central

Guha, Rajdeep; Jongkey, Geram; Palui, Himangshu; Mishra, Akhilesh; Vemuganti, Geeta K.; Basak, Samar K.; Mandal, Tapan Kumar; Konar, Aditya

2012-01-01

Purpose To evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on posterior capsular opacification (PCO) of rabbits and to assess its effect on intraocular tissues. Methods Modulation of matrix metalloproteinase (MMP) activity in the aqueous following cataract surgery in rabbits and its prevention by different doses of EDTA was determined by zymography. For evaluation of PCO, lensectomized rabbits were intracamerally injected with single dose of either 5 mg EDTA or normal saline. After one month, the degree of PCO was determined by slitlamp biomicroscopy, Miyake-Apple view, and histology of the lens capsule. The effect of EDTA on intra ocular pressure (IOP), corneal endothelial cells, and the retina was evaluated by tonometry, specular microscopy and scanning electron microscopy, and electroretinography. The concentration of EDTA in the aqueous was determined by high performance liquid chromatography (HPLC) at different time points. Results The MMP activity was significantly increased in the aqueous of the operated eyes, and EDTA reduced the degree of increase in a dose-dependent manner. EDTA treatment significantly reduced the degree of PCO (p<0.05). Histopathology of the lens capsule showed a reduction in the number of proliferating and migrating cells as well as MMP2 expression in the EDTA-treated eyes. EDTA treatment did not change the IOP; density, morphology and ultrastructure of the corneal endothelial cells; and electroretinography (ERG). EDTA was detectable in the aqueous humor up to 72 h following a single intracameral injection. Conclusions EDTA reduces the degree of PCO by suppressing the MMP activity and it is not toxic to intra ocular structures at the concentration used. PMID:22815623

Enhancement of pharmacokinetic and pharmacological behavior of ocular dorzolamide after factorial optimization of self-assembled nanostructures

PubMed Central

Afify, Enas A. M. R.; Elsayed, Ibrahim; Gad, Mary K.; Mohamed, Magdy I.

2018-01-01

Dorzolamide hydrochloride is frequently administered for the control of the intra-ocular pressure associated with glaucoma. The aim of this study is to develop and optimize self-assembled nanostructures of dorzolamide hydrochloride and L-α-Phosphatidylcholine to improve the pharmacokinetic parameters and extend the drug pharmacological action. Self-assembled nanostructures were prepared using a modified thin-film hydration technique. The formulae compositions were designed based on response surface statistical design. The prepared self-assembled nanostructures were characterized by testing their drug content, particle size, polydispersity index, zeta potential, partition coefficient, release half-life and extent. The optimized formulae having the highest drug content, zeta potential, partition coefficient, release half-life and extent with the lowest particle size and polydispersity index were subjected to further investigations including investigation of their physicochemical, morphological characteristics, in vivo pharmacokinetic and pharmacodynamic profiles. The optimized formulae were prepared at pH 8.7 (F5 and F6) and composed of L-α-Phosphatidylcholine and drug mixed in a ratio of 1:1 and 2:1 w/w, respectively. They showed significantly higher Cmax, AUC024 and AUC0∞ at the aqueous humor with extended control over the intra-ocular pressure, when compared to the marketed product; Trusopt®. The study introduced novel and promising self-assembled formulae able to permeate higher drug amount through the cornea and achieve sustained pharmacological effect at the site of action. PMID:29401498

Genetic correlations between intraocular pressure, blood pressure and primary open-angle glaucoma: a multi-cohort analysis.

PubMed

Aschard, Hugues; Kang, Jae H; Iglesias, Adriana I; Hysi, Pirro; Cooke Bailey, Jessica N; Khawaja, Anthony P; Allingham, R Rand; Ashley-Koch, Allison; Lee, Richard K; Moroi, Sayoko E; Brilliant, Murray H; Wollstein, Gadi; Schuman, Joel S; Fingert, John H; Budenz, Donald L; Realini, Tony; Gaasterland, Terry; Scott, William K; Singh, Kuldev; Sit, Arthur J; Igo, Robert P; Song, Yeunjoo E; Hark, Lisa; Ritch, Robert; Rhee, Douglas J; Gulati, Vikas; Haven, Shane; Vollrath, Douglas; Zack, Donald J; Medeiros, Felipe; Weinreb, Robert N; Cheng, Ching-Yu; Chasman, Daniel I; Christen, William G; Pericak-Vance, Margaret A; Liu, Yutao; Kraft, Peter; Richards, Julia E; Rosner, Bernard A; Hauser, Michael A; Klaver, Caroline C W; vanDuijn, Cornelia M; Haines, Jonathan; Wiggs, Janey L; Pasquale, Louis R

2017-11-01

Primary open-angle glaucoma (POAG) is the most common chronic optic neuropathy worldwide. Epidemiological studies show a robust positive relation between intraocular pressure (IOP) and POAG and modest positive association between IOP and blood pressure (BP), while the relation between BP and POAG is controversial. The International Glaucoma Genetics Consortium (n=27 558), the International Consortium on Blood Pressure (n=69 395), and the National Eye Institute Glaucoma Human Genetics Collaboration Heritable Overall Operational Database (n=37 333), represent genome-wide data sets for IOP, BP traits and POAG, respectively. We formed genome-wide significant variant panels for IOP and diastolic BP and found a strong relation with POAG (odds ratio and 95% confidence interval: 1.18 (1.14-1.21), P=1.8 × 10 -27 ) for the former trait but no association for the latter (P=0.93). Next, we used linkage disequilibrium (LD) score regression, to provide genome-wide estimates of correlation between traits without the need for additional phenotyping. We also compared our genome-wide estimate of heritability between IOP and BP to an estimate based solely on direct measures of these traits in the Erasmus Rucphen Family (ERF; n=2519) study using Sequential Oligogenic Linkage Analysis Routines (SOLAR). LD score regression revealed high genetic correlation between IOP and POAG (48.5%, P=2.1 × 10 -5 ); however, genetic correlation between IOP and diastolic BP (P=0.86) and between diastolic BP and POAG (P=0.42) were negligible. Using SOLAR in the ERF study, we confirmed the minimal heritability between IOP and diastolic BP (P=0.63). Overall, IOP shares genetic basis with POAG, whereas BP has limited shared genetic correlation with IOP or POAG.

A multicenter, retrospective chart review study comparing index therapy change rates in open-angle glaucoma or ocular hypertension patients newly treated with latanoprost or travoprost-Z monotherapy.

PubMed

Fain, Joel M; Kotak, Sameer; Mardekian, Jack; Bacharach, Jason; Edward, Deepak P; Rauchman, Steven; Brevetti, Teresa; Fox, Janet L; Lovelace, Cherie

2011-06-13

Because latanoprost and the original formulation of travoprost that included benzalkonium chloride (BAK) have been shown to be similar with regard to tolerability, we compared initial topical intraocular pressure (IOP)-lowering medication change rates in patients newly treated with latanoprost or travoprost-Z monotherapy. At 14 clinical practice sites, medical records were abstracted for patients with a diagnosis of open-angle glaucoma or ocular hypertension and who were ≥40 years of age, had a baseline and at least one follow-up visit, and had no prior history of ocular prostaglandin use. Data regarding demographics, ocular/systemic medical histories, clinical variables, therapy initiations and reasons for changes, adverse events, and resource utilization were recorded from randomly chosen eligible charts. Primary outcomes were rates of and reasons for changing from the initial therapy within six months and across the full study period (1000 days). Data from 900 medical charts (latanoprost, 632; travoprost-Z, 268) were included. For both cohorts, average follow-up was >1 year. Cohorts were similar with regard to age (median ~67 years), gender distribution (>50% female), and diagnosis (~80% with open-angle glaucoma). Within six months, rates of index therapy change for latanoprost versus travoprost-Z were 21.2% (134/632) and 28.7% (77/268), respectively (p = 0.0148); across the full study period, rates were 34.5% (218/632) and 45.2% (121/268), respectively (p = 0.0026). Among those who changed their index therapy, insufficient IOP control was the most commonly reported reason followed by adverse events; hyperemia was the most commonly reported adverse event at index therapy change. In this "real world" study of changes in therapy in patients prescribed initial monotherapy with latanoprost with BAK or travoprost-Z with SofZia, medication changes were common in both treatment groups but statistically significantly more frequent with travoprost-Z.

Clinical Features and Risk Factors of Patients with Presumed Ocular Toxoplasmosis.

PubMed

Fuh, Ukamaka Celestina; Omoti, Afekhide E; Enock, Malachi E

2016-01-01

To determine the clinical features and risk factors of presumed ocular toxoplasmosis (POT) in patients affected with the condition at Irrua, Nigeria. The study included 69 patients with POT, and 69 age and sex matched subjects who served as the control group. Data was obtained using interviewer administered questionnaires. Examination included measurement of visual acuity (VA), intraocular pressure (IOP), slit lamp examination, gonioscopy and dilated fundus examination. Mean age of cases and control subjects was 57.16 ± 18.69 and 56.09 ± 16.01 years respectively. The peak age group in patients with POT was 60 years and above. The most common presenting complaint was blurred vision occurring in 100% of cases. Drinking unfiltered water in 58 (84.1%) patients was the most common risk factor. Other risk factors included post cataract surgery status in 32 (46.4%) subjects, ingestion of poorly cooked meat in 30 (43.5%) cases and exposure to cats in 9 (13.0%) patients. All risk factors were more common in POT patients (P < 0.05). Out of 69 patients, 62 (89.9%) had unilateral while 7 (10.1%) had bilateral involvement. Out of 76 eyes with uveitis, 53 (69.7%) were blind. Active disease was significantly more common with increasing age (P < 0.05). Patients with POT were rather old and some risk factors were modifiable, therefore health education for preventing the transmission of toxoplasmosis and provision of sanitary water may help reduce the incidence of ocular toxoplasmosis.

Risk of Microgravity-Induced Visual Impairment and Elevated Intracranial Pressure (VIIP)

NASA Technical Reports Server (NTRS)

Otto, Christian

2011-01-01

Eight cases identified, represent 23.5% of the 34 crewmembers flown on the ISS, with inflight visual changes and pre-to-postflight refractive changes. In some cases, the changes were transient while in others they are persistent with varying degrees of visual impairment. (1) Decreased intraocular pressure (IOP) postflight was observed in 3 cases. (2) Fundoscopic exams revealed postflight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and presence of cotton wool spots in 3 cases. (3) Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema and documented retinal nerve fiber layer thickening (4 cases). (4) Findings from MRI examinations showed posterior globe flattening (5 cases) and optic nerve sheath distension (6 cases). (5) Opening cerebrospinal fluid (CSF) pressure was elevated in 4 cases postflight reflecting raised intracranial pressure. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes in astronauts.

An Applet to Estimate the IOP-Induced Stress and Strain within the Optic Nerve Head

PubMed Central

2011-01-01

Purpose. The ability to predict the biomechanical response of the optic nerve head (ONH) to intraocular pressure (IOP) elevation holds great promise, yet remains elusive. The objective of this work was to introduce an approach to model ONH biomechanics that combines the ease of use and speed of analytical models with the flexibility and power of numerical models. Methods. Models representing a variety of ONHs were produced, and finite element (FE) techniques used to predict the stresses (forces) and strains (relative deformations) induced on each of the models by IOP elevations (up to 10 mm Hg). Multivariate regression was used to parameterize each biomechanical response as an analytical function. These functions were encoded into a Flash-based applet. Applet utility was demonstrated by investigating hypotheses concerning ONH biomechanics posited in the literature. Results. All responses were parameterized well by polynomials (R2 values between 0.985 and 0.999), demonstrating the effectiveness of our fitting approach. Previously published univariate results were reproduced with the applet in seconds. A few minutes allowed for multivariate analysis, with which it was predicted that often, but not always, larger eyes experience higher levels of stress and strain than smaller ones, even at the same IOP. Conclusions. An applet has been presented with which it is simple to make rapid estimates of IOP-related ONH biomechanics. The applet represents a step toward bringing the power of FE modeling beyond the specialized laboratory and can thus help develop more refined biomechanics-based hypotheses. The applet is available for use at www.ocularbiomechanics.com. PMID:21527378

Ocular hemodynamic effects of nitrovasodilators in healthy subjects.

PubMed

Schmidl, D; Polska, E; Kiss, B; Sacu, S; Garhofer, G; Schmetterer, L

2010-01-01

Nitric oxide (NO) plays a key role in the regulation of ocular blood flow and may be an interesting therapeutic target in ocular ischemic disease. In the present study, we hypothesized that NO-releasing drugs may increase blood flow to the head of the optic nerve and also in the choroid. The study employed a randomized, placebo-controlled, double blind, four-way crossover design. On separate study days, 12 healthy subjects received infusions of nitroglycerin, isosorbide dinitrate, sodium nitroprusside, or placebo. All three study drugs reduced the mean arterial pressure (MAP) and ocular perfusion pressure (OPP) (P < 0.001). None of the administered drugs increased the ocular hemodynamic variables. By contrast, vascular resistance decreased dose dependently during administration of the study drugs (P < 0.001). These results indicate that systemic administration of NO-donor drugs is associated with a decrease in vascular resistance in the ocular vasculature. However, because these drugs also reduce blood pressure, they do not improve perfusion to the posterior eye pole.

Extracapsular cataract extraction with and without intra-ocular lenses in black patients.

PubMed

Welsh, N H

1992-04-04

Cataracts are the commonest cause of blindness in Third-World countries and cataract extraction is the commonest eye operation performed anywhere. Patients require optical correction after surgery either in the form of an intra-ocular lens (IOL) or bifocal aphakic glasses. The standard operative procedure in First-World countries is an extracapsular cataract extraction with an IOL. This type of operation has been thought to be contraindicated in black patients because of the complications and lack of adequate postoperative follow-up. During 1987-1989 3,144 cataract extractions, of which 2,157 were simple extracapsular extractions and 987 had IOLs inserted, were performed at the above hospitals. The two groups were compared for complications and visual results. The complications were similar in both groups and were acceptable, therefore posterior lens implantation confers no additional risk on routine extracapsular cataract extraction. The visual results in the IOL group with and without additional glasses were compared with those patients who had correcting aphakic glasses. In the corrected IOL group, 98% of patients saw better than 6/24, whereas in the aphakic spectacle group, 87.5% saw 6/24 or better. Since the majority of black patients cannot afford costly prescribed spectacles, it was important to analyse the visual acuity in patients who had IOLs and were uncorrected; 81.6% saw 6/24 or better. IOLs in black patients are therefore indicated but the disadvantage is the cost.

Escompte Field Experiment : Some Preliminary Results About The Iop 2

NASA Astrophysics Data System (ADS)

Cros, B.; Durand, P.; Ancellet, G.; Calpini, B.; Frejafon, E.; Jambert, C.; Serça, D.; Sol, B.; Wortham, H.; Zephoris, M.

One of the main goals of the ESCOMPTE programme is to create an appropriate -3D data base including emissions, transport and air composition measurements during urban pollution episodes. ESCOMPTE will as well as provide a highly documented framework for dynamical and chemical studies. For this purpose a field campaign was carried out in Marseille -Berre area in the south-eastern of France from June 4 to July 13, 2001. Five pollution events (IOP) were documented. The second one called IOP2 is particularly interesting in term of photochemical pollution. The chemical evolution of the urban and industrial plumes and the orographic influence are analysed from surface, remote sensing and airborne measurements. This IOP 2 of six days duration ( June 21 to June 26) will be presented . It began with a moderate S/SW wind (an end of Mistral situation) , clear skies and hot temperature (>30rC). Marseille and Berre plumes extended towards the East and over the sea. The highest surface ozone concentration were found around Toulon area. This first period (23-26/06) so called IOP 2a was followed by IOP 2b, three days of very hot temperature (>34rC) and high surface concentration in ozone - 100 ppbv over the whole domain , 125 ppbv all around Aix on the 24 up to 150 ppbv in the durance valley on the 25.

Reliability of laser Doppler flowmetry curve reading for measurement of toe and ankle pressures: intra- and inter-observer variation.

PubMed

Høyer, C; Paludan, J P D; Pavar, S; Biurrun Manresa, J A; Petersen, L J

2014-03-01

To assess the intra- and inter-observer variation in laser Doppler flowmetry curve reading for measurement of toe and ankle pressures. A prospective single blinded diagnostic accuracy study was conducted on 200 patients with known or suspected peripheral arterial disease (PAD), with a total of 760 curve sets produced. The first curve reading for this study was performed by laboratory technologists blinded to clinical clues and previous readings at least 3 months after the primary data sampling. The pressure curves were later reassessed following another period of at least 3 months. Observer agreement in diagnostic classification according to TASC-II criteria was quantified using Cohen's kappa. Reliability was quantified using intra-class correlation coefficients, coefficients of variance, and Bland-Altman analysis. The overall agreement in diagnostic classification (PAD/not PAD) was 173/200 (87%) for intra-observer (κ = .858) and 175/200 (88%) for inter-observer data (κ = .787). Reliability analysis confirmed excellent correlation for both intra- and inter-observer data (ICC all ≥.931). The coefficients of variance ranged from 2.27% to 6.44% for intra-observer and 2.39% to 8.42% for inter-observer data. Subgroup analysis showed lower observer-variation for reading of toe pressures in patients with diabetes and/or chronic kidney disease than patients not diagnosed with these conditions. Bland-Altman plots showed higher variation in toe pressure readings than ankle pressure readings. This study shows substantial intra- and inter-observer agreement in diagnostic classification and reading of absolute pressures when using laboratory technologists as observers. The study emphasises that observer variation for curve reading is an important factor concerning the overall reproducibility of the method. Our data suggest diabetes and chronic kidney disease have an influence on toe pressure reproducibility. Copyright © 2013 European Society for Vascular Surgery. Published

The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head Deformation

NASA Technical Reports Server (NTRS)

Feola, Andrew J.; Myers, Jerry G.; Raykin, Julia; Nelson, Emily S.; Samuels, Brian C.; Ethier C. Ross

2017-01-01

Alteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.

Color of intra-ocular lens and cataract type are prognostic determinants of health indices after visual and photoreceptive restoration by surgery.

PubMed

Ayaki, Masahiko; Negishi, Kazuno; Suzukamo, Yoshimi; Tsubota, Kazuo

2015-04-01

This study compared post-operative quality of life and sleep according to the type of cataract opacity and color of the implanted intra-ocular lens (IOL). This is a cohort study and participants were 206 patients (average age 74.1 years) undergoing cataract surgery with the implantation of a clear ultra-violet (UV)-blocking IOL (C) or a yellow blue-light-blocking IOL (Y). Participants were evaluated using the National Eye Institute Visual Function Questionnaire (VFQ-25) and Pittsburgh Sleep Quality Index (PSQI) before surgery and 2 and 7 months after surgery. Changes in sub-scale scores of VFQ-25 and PSQI were compared. Sub-scale analyses for improvement after surgery revealed significant differences in ocular pain scores on the VFQ-25 (Y>C; the higher the score, the better the outcome). Furthermore, there were significant differences between the two IOLs in terms of the sleep latency score (C>Y) and sleep disturbances score (C>Y). A posterior sub-capsular cataract was significantly correlated with improvements in ocular pain and sleep latency scores. These effects were successfully represented by the change in scores rather than absolute post-operative scores because individual standard of response may often change after intervention, recognized as a response shift phenomenon in patient-reported outcome study. Regarding seasonal differences, patients who had surgery in summer exhibited relatively better sleep quality than those who had surgery in winter. Analysis of sub-scales of health indices demonstrated characteristic prognoses for each IOL and cataract type. Cataract surgery may potentially contribute to systemic health in older adults.

Dynamic changes of the intraocular pressure and the pressure of cerebrospinal fluid in nonglaucomatous neurological patients.

PubMed

González-Camarena, Pedro Iván; San-Juan, Daniel; González-Olhovich, Irene; Rodríguez-Arévalo, David; Lozano-Elizondo, David; Trenado, Carlos; Anschel, David J

2017-03-01

To describe the dynamic changes of the intraocular pressure (IOP) and intracranial pressure (ICP) with normal or pathological values (intracranial hypertension) in nonglaucomatous neurological patients during lumbar punction (LP). Case-control study, prospective measurement of tonometry in both groups referred for LP. Intraocular pressure, ICP and translaminar pressure difference (TPD) were compared pre- and post-LP. Thirty-six patients (72 eyes) with mean age of 38.5 (16-64) years and BMI of 26.81 kg/m 2 were analysed. The initial mean ICP was 12.81 (± 6.6) mmHg. The mean TPD before and after the LP was 1.48 mmHg and 0.65 mmHg, respectively. The mean IOP of both eyes decreased to 0.8 mmHg post-LP in patients with pathological ICP (p = 0.0193) and normal ICP (p = 0.006). We found a statistically significant decrease of the IOP post-LP compared to the pre-LP in both groups, being higher in patients with pathological ICP. There were no significant differences of the IOP in patients with normal versus pathological ICP pre-LP/post-LP; neither was found a correlation between ICP and IOP. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Effect of Cromakalim Prodrug 1 (CKLP1) on Aqueous Humor Dynamics and Feasibility of Combination Therapy With Existing Ocular Hypotensive Agents

PubMed Central

Roy Chowdhury, Uttio; Rinkoski, Tommy A.; Bahler, Cindy K.; Millar, J. Cameron; Bertrand, Jacques A.; Holman, Bradley H.; Sherwood, Joseph M.; Overby, Darryl R.; Stoltz, Kristen L.; Dosa, Peter I.; Fautsch, Michael P.

2017-01-01

Purpose Cromakalim prodrug 1 (CKLP1) is a water-soluble ATP-sensitive potassium channel opener that has shown ocular hypotensive properties in ex vivo and in vivo experimental models. To determine its mechanism of action, we assessed the effect of CKLP1 on aqueous humor dynamics and in combination therapy with existing ocular hypotensive agents. Methods Outflow facility was assessed in C57BL/6 mice by ex vivo eye perfusions and by in vivo constant flow infusion following CKLP1 treatment. Human anterior segments with no trabecular meshwork were evaluated for effect on pressure following CKLP1 treatment. CKLP1 alone and in combination with latanoprost, timolol, and Rho kinase inhibitor Y27632 were evaluated for effect on intraocular pressure in C57BL/6 mice and Dutch-belted pigmented rabbits. Results CKLP1 lowered episcleral venous pressure (control: 8.9 ± 0.1 mm Hg versus treated: 6.2 ± 0.1 mm Hg, P < 0.0001) but had no detectable effect on outflow facility, aqueous humor flow rate, or uveoscleral outflow. Treatment with CKLP1 in human anterior segments without the trabecular meshwork resulted in a 50% ± 9% decrease in pressure, suggesting an effect on the distal portion of the conventional outflow pathway. CKLP1 worked additively with latanoprost, timolol, and Y27632 to lower IOP, presumably owing to combined effects on different aspects of aqueous humor dynamics. Conclusions CKLP1 lowered intraocular pressure by reducing episcleral venous pressure and lowering distal outflow resistance in the conventional outflow pathway. Owing to this unique mechanism of action, CKLP1 works in an additive manner to lower intraocular pressure with latanoprost, timolol, and Rho kinase inhibitor Y27632. PMID:29114841

Pharmacokinetic basis for nonadditivity of intraocular pressure lowering in timolol combinations.

PubMed

Lee, V H; Luo, A M; Li, S Y; Podder, S K; Chang, J S; Ohdo, S; Grass, G M

1991-10-01

The authors determined whether the ocular absorption of topically applied timolol in the pigmented rabbit was affected significantly by coadministration with either pilocarpine or epinephrine in the same drop to explain the nonadditivity in intraocular pressure lowering (IOP) seen clinically. They instilled 25 microliters of 0.65% timolol maleate solution (equivalent to 0.5% timolol), both in the presence and absence of 2.6% pilocarpine nitrate or 1% epinephrine bitartrate, into pigmented rabbit eyes. The time course of timolol concentration in the conjunctiva, anterior sclera, corneal epithelium, corneal stroma, aqueous humor, iris-ciliary body, and lens was monitored for 360 min by using reversed-phase high-performance liquid chromatography. The area under the timolol concentration-time curve in all but one of the anterior segment tissues was reduced by 20-50% (mean, 40%) when timolol was coadministered with pilocarpine and by 20-70% (mean, 42%) when timolol was coadministered with epinephrine. Such an effect was not a result of alterations in corneal permeability or aqueous humor turnover rate, nor was it related to the extent of systemic absorption caused by pilocarpine and epinephrine. Rather, the reduction in ocular timolol absorption may have been caused by the accelerated washout of timolol by tears stimulated by the coadministered drugs and, to a lesser extent, by the loss of timolol through binding to the increased amount of tear proteins induced by the coadministered drugs. Thus, the nonadditivity in IOP lowering from timolol-pilocarpine and timolol-epinephrine combinations is probably caused by changes in precorneal timolol clearance.

What We Have Learned From the Ocular Hypertension Treatment Study.

PubMed

Gordon, Mae O; Kass, Michael A

2018-05-01

To identify results from the Ocular Hypertension Study that can aid patients and clinicians to make evidence-based decisions about the management of ocular hypertension. Perspective. At 60 months, the cumulative frequency of developing primary open-angle glaucoma (POAG) was 4.4% in the medication group and 9.5% in the observation group (hazard ratio for medication, 0.40; 95% confidence interval [CI], 0.27-0.59; P < .0001). At 13 years the cumulative proportion of participants who developed POAG was 0.22 (95% CI 0.19-0.25) in the original observation group and 0.16 (95% CI 0.13-0.19) in the original medication group (complementary log-log x 2 P = .009). A 5-factor model (older age, higher IOP, thinner central corneal thickness, larger cup-to-disc ratio, and higher visual field pattern standard deviation) separated participants at high and low risk of developing POAG. Clinicians and patients can make evidence-based decisions about the management of ocular hypertension using the risk model and considering patient age, medical status, life expectancy, and personal preference. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of adenosine on intraocular pressure, optic nerve head blood flow, and choroidal blood flow in healthy humans.

PubMed

Polska, Elzbieta; Ehrlich, Paulina; Luksch, Alexandra; Fuchsjäger-Mayrl, Gabriele; Schmetterer, Leopold

2003-07-01

There is evidence from a variety of animal studies that the adenosine system plays a role in the control of intraocular pressure (IOP) and ocular blood flow. However, human data on the effect of adenosine on IOP and choroidal and optic nerve blood flow are not available. The effect of stepwise increases in doses of adenosine (10, 20, and 40 micro g/kg per minute, 30 minutes per infusion step) on optic nerve head blood flow, choroidal blood flow, and IOP was determined in a placebo-controlled double-masked clinical trial in 12 healthy male volunteers. Blood flow in the optic nerve head and choroid was measured with laser Doppler flowmetry. In addition, fundus pulsation amplitude in the macula (FPAM) and the optic nerve head (FPAO) were assessed with laser interferometry. Adenosine induced a small but significant decrease in IOP (at 40 microg/kg per minute: 12% +/- 13%), which was significant versus placebo (P = 0.046). In addition, adenosine induced a significant increase in choroidal blood flow (P < 0.001) and optic nerve head blood flow (P = 0.037), and FPAM (P = 0.0014) and tended to increase FPAO (P = 0.057). At the highest administered dose, the effect on choroidal hemodynamic parameters between 14% and 17%, whereas the effect on optic nerve hemodynamic parameters was between 3% and 11%. These data are consistent with adenosine inducing choroidal and optic nerve head vasodilatation and reducing IOP in healthy humans. Considering the neuroprotective properties of adenosine described in previous animal experiments the adenosine system is an attractive target system for therapeutic approaches in glaucoma.

Assessment of ocular hypotensive effect and safety 12 months after changing from an unfixed combination to a latanoprost 0.005% + timolol maleate 0.5% fixed combination.

PubMed

Inoue, Kenji; Okayama, Ryoko; Higa, Risako; Wakakura, Masato; Tomita, Goji

2012-01-01

Latanoprost 0.005% + timolol maleate 0.5% combined eyedrops were recently made available in Japan. We prospectively investigated the intraocular pressure (IOP)-lowering effect, visual preservation effect, and adverse reactions of a one-year administration of this fixed combination. The subjects included 162 eyes from 162 patients diagnosed with either primary open-angle glaucoma or ocular hypertension and using an unfixed combination of latanoprost 0.005% and timolol maleate 0.5%. The unfixed combination was discontinued and replaced with the latanoprost 0.005% + timolol maleate 0.5% fixed combination with no washout period. IOP was measured before (baseline) and 3, 6, 9, and 12 months after the change. The mean deviation value of Humphrey field analysis was compared. Adverse reactions were examined at every follow-up. No significant differences were found between mean IOP values obtained at baseline (mean ± standard deviation, 15.2 ± 3.3 mmHg) 3 months (15.1 ± 3.2 mmHg), 6 months (15.3 ± 3.1 mmHg), 9 months (15.3 ± 3.1 mmHg), and 12 months (15.1 ± 3.2 mmHg) after the change from the unfixed to the fixed combination of eyedrops (P = 0.212). In addition, no significant differences were observed between mean deviation values obtained at baseline (-9.11 ± 6.94 dB) and 12 months (-10.08 ± 7.24 dB) after the change (P = 0.114). Thirty-one patients discontinued the fixed combination within 12 months of replacement, due to an insufficient IOP decrease (20 patients, 12.3%) and adverse reactions (11 patients, 6.8%). Following replacement of two eyedrop medications (latanoprost 0.005% and timolol maleate 0.5%) by one fixed combination (latanoprost 0.005% + timolol maleate 0.5%), IOP and visual field were preserved. However, 20% of the patients discontinued the new treatment because of an insufficient IOP decrease and complaints of adverse reactions.

The impact of glaucoma referral refinement criteria on referral to, and first-visit discharge rates from, the hospital eye service: the Health Innovation & Education Cluster (HIEC) Glaucoma Pathways project.

PubMed

Ratnarajan, Gokulan; Newsom, Wendy; French, Karen; Kean, Jane; Chang, Lydia; Parker, Mike; Garway-Heath, David F; Bourne, Rupert R A

2013-03-01

To assess the impact of referral refinement criteria on the number of patients referred to, and first-visit discharges from, the Hospital Eye Service (HES) in relation to the National Institute for Health & Clinical Excellence (NICE) Glaucoma Guidelines, Joint College Group Guidance (JCG) and the NICE commissioning guidance. All low-risk (one risk factor: suspicious optic disc, abnormal visual field (VF), raised intra-ocular pressure (IOP) (22-28 mmHg) or IOP asymmetry (>5 mmHg) and high-risk (more than one risk factor, shallow anterior chamber or IOP >28 mmHg) referrals to the HES from 2006 to 2011 were analysed. Low-risk referrals were seen by Optometrists with a specialist interest in glaucoma and high-risk referrals were referred directly to the HES. Two thousand nine hundred and twelve patient records were analysed. The highest Consultant first-visit discharge rates were for referrals based on IOP alone (45% for IOP 22-28 mmHg) and IOP asymmetry (53%), VF defect alone (46%) and for abnormal IOP and VF (54%). The lowest first-visit discharge rates were for referrals for suspicious optic disc (19%) and IOP >28 mmHg (22%). 73% of patients aged 65-80 and 60% of patients aged >80 who were referred by the OSI due to an IOP between 22-28 mmHg would have satisfied the JCG criteria for non-referral. For patients referred with an IOP >28 mmHg and an otherwise normal examination, adherence to the NICE commissioning guidance would have resulted in 6% fewer referrals. In 2010 this scheme reduced the number of patients attending the HES by 15%, which resulted in a saving of £16 258 (13%). The results support that referrals for a raised IOP alone or in combination with an abnormal VF be classified as low-risk and undergo referral refinement. Adherence to the JCG and the NICE commissioning guidance as onward referral criteria for specialist optometrists in this referral refinement scheme would result in fewer referrals. Ophthalmic & Physiological Optics © 2013 The College

sCD44 overexpression increases intraocular pressure and aqueous outflow resistance

PubMed Central

Giovingo, Michael; Nolan, Michael; McCarty, Ryan; Pang, Iok-Hou; Clark, Abbot F.; Beverley, Rachel M.; Schwartz, Steven; Stamer, W. Daniel; Walker, Loyal; Grybauskas, Algis; Skuran, Kevin; Kuprys, Paulius V.; Yue, Beatrice Y.J.T.

2013-01-01

Purpose CD44 plays major roles in multiple physiologic processes. The ectodomain concentration of the CD44 receptor, soluble CD44 (sCD44), is significantly increased in the aqueous humor of primary open-angle glaucoma (POAG). The purpose of this study was to determine if adenoviral constructs of CD44 and isolated 32-kDa sCD44 change intraocular pressure (IOP) in vivo and aqueous outflow resistance in vitro. Methods Adenoviral constructs of human standard CD44 (Ad-CD44S), soluble CD44 (Ad-sCD44), and empty viral cDNA were injected into the vitreous of BALB/cJ mice, followed by serial IOP measurements. Overexpression of CD44S and sCD44 was verified in vitro by enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Anterior segments of porcine eyes were perfused with the isolated sCD44. sCD44-treated human trabecular meshwork (TM) cells and microdissected porcine TM were examined by confocal microscopy and Optiprep density gradient with western blot analysis to determine changes in lipid raft components. Results Intravitreous injection of adenoviral constructs with either Ad-CD44S or Ad-sCD44 vectors caused prolonged ocular hypertension in mice. Eight days after vector injection, Ad-CD44S significantly elevated IOP to 28.3±1.2 mmHg (mean±SEM, n=8; p<0.001); Ad-sCD44 increased IOP to 18.5±2.6 mmHg (n=8; p<0.01), whereas the IOP of uninjected eyes was 12.7±0.2 mmHg (n=16). The IOP elevation lasted more than 50 days. Topical administration of a γ-secretase inhibitor normalized Ad-sCD44-induced elevated IOP. sCD44 levels were significantly elevated in the aqueous humor of Ad-CD44S and Ad-sCD44 eyes versus contralateral uninjected eyes (p<0.01). Anterior segment perfusion of isolated 32-kDa sCD44 significantly decreased aqueous outflow rates. Co-administration of isolated sCD44 and CD44 neutralizing antibody or of γ-secretase inhibitor significantly enhanced flow rates. sCD44-treated human TM cells displayed cross-linked actin network formation

The usefulness of CorvisST Tonometry and the Ocular Response Analyzer to assess the progression of glaucoma

NASA Astrophysics Data System (ADS)

Matsuura, Masato; Hirasawa, Kazunori; Murata, Hiroshi; Nakakura, Shunsuke; Kiuchi, Yoshiaki; Asaoka, Ryo

2017-01-01

Corneal Visualization Scheimpflug Technology (CST) and Ocular Response Analyzer (ORA) measurements were carried out in 105 eyes of 69 patients with primary open-angle glaucoma. All patients had axial length (AL), central corneal thickness (CCT), intraocular pressure (IOP) with Goldmann applanation tonometry (GAT) and eight visual fields (VF)s with the Humphrey Field Analyzer. VF progression was summarized using a time trend analysis of mean total deviation (mTD) and the association between mTD progression rate and a number of ocular parameters (including CST and ORA measurements) was assessed using mixed linear regression analysis. The optimal model of VF progression selected based on the corrected Akaike Information Criteria (AICc) included ORA’s corneal hysteresis (CH) parameter as well as a number of CST measurements: mTD progression rate = 1.2-0.070 * mean GAT + 0.090 * CH-1.5 * highest concavity deformation amplitude with CST + 9.4 * A1 deformation amplitude with CST-0.05 * A2 length with CST (AICc = 125.8). Eyes with corneas that experience deep indentation at the maximum deformation, shallow indentation at the first applanation and wide indentation at the second applanation in the CST measurement are more likely to experience faster rates of VF progression.

Effect of pegaptanib sodium 0.3 mg intravitreal injections (Macugen) in intraocular pressure: posthoc analysis from V.I.S.I.O.N. study.

PubMed

Boyer, David S; Goldbaum, Mauro; Leys, Anita M; Starita, Carla

2014-11-01

To assess the rate of pegaptanib-associated sustained intraocular pressure (IOP) elevation. A posthoc analysis was conducted on all IOP measurements, except the immediate 30-min postinjection, from all subjects randomised to pegaptanib 0.3 mg or sham injections continuously in the first 2 years of the Vascular endothelial growth factor Inhibition Study in Ocular Neovascularisation (V.I.S.I.O.N.) study. Measurements were taken with Goldmann applanation tonometer or Tonopen, except at baseline and in cases of an IOP reading >30 mm Hg when a Goldmann applanation tonometer was mandatory. Of 221 subjects, IOP measurements ≥22 mm Hg were seen in 28/114 and 23/107 subjects of the pegaptanib and sham subgroups, respectively (p=0.6338) and measurements ≥24 mm Hg were observed in eight and eight subjects in the pegaptanib and sham groups, respectively. More than two measurements ≥22 mm Hg occurred in six and 10 subjects (p=0.3025), and more than two measurements ≥24 mm Hg were observed in one and four subjects in the pegaptanib and sham groups, respectively. One patient with sustained IOP elevation in the pegaptanib study group, and four in the sham group, had IOP lowering medication added during the course of the study. No subject required glaucoma surgery. In V.I.S.I.O.N., after 2 years, there was no evidence of sustained IOP elevation associated with pegaptanib 0.3 mg use. NCT00321997. 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.

Beat-to-beat agreement of noninvasive tonometric and intra-radial arterial blood pressure during microgravity and hypergravity generated by parabolic flights.

PubMed

Normand, Hervé; Lemarchand, Erick; Arbeille, Philippe; Quarck, Gaëlle; Vaïda, Pierre; Duretete, Arnaud; Denise, Pierre

2007-12-01

Accurate measurement of beat-to-beat arterial blood pressure is essential for understanding the cardiovascular adaptation to weightlessness; however, the intra-arterial standard of beat-to-beat blood pressure measurement has never been used during space flight because of its invasive nature. The aim of the present study was to compare noninvasive radial artery tonometry blood pressure measurement with intra-radial pressure measurement during microgravity and hypergravity generated by parabolic flights. Two study participants, equipped with an intra-radial pressure line on the left arm and a Colin CBM-7000 (Colin Corp., Komaki City, Japan) beat-to-beat pressure measurement apparatus on the right arm, were studied in a supine position, during parabolic flights on board of the Airbus A300 OG of the Centre National d'Etudes Spatiales. The mean and standard deviations of the beat-to-beat difference between tonometric and intra-radial blood pressure were calculated for systolic and diastolic arterial pressure in the three gravity conditions (1g, 0 g and 1.8 g) experienced during parabolic flight. The Colin CBM-7000 met the specifications required by the Association for the Advancement of Medical Instrumentation in the 0 g environment. Gravity, however, significantly affected the difference between tonometric and intra-arterial blood pressure, possibly owing to the effect of gravity on the apparent weight of the device and the corresponding calibration factor. We conclude that the Colin CBM-7000 can be used with confidence during space flight.

Driving time modulates accommodative response and intraocular pressure.

PubMed

Vera, Jesús; Diaz-Piedra, Carolina; Jiménez, Raimundo; Morales, José M; Catena, Andrés; Cardenas, David; Di Stasi, Leandro L

2016-10-01

Driving is a task mainly reliant on the visual system. Most of the time, while driving, our eyes are constantly focusing and refocusing between the road and the dashboard or near and far traffic. Thus, prolonged driving time should produce visual fatigue. Here, for the first time, we investigated the effects of driving time, a common inducer of driver fatigue, on two ocular parameters: the accommodative response (AR) and the intraocular pressure (IOP). A pre/post-test design has been used to assess the impact of driving time on both indices. Twelve participants (out of 17 recruited) completed the study (5 women, 24.42±2.84years old). The participants were healthy and active drivers with no visual impairment or pathology. They drove for 2h in a virtual driving environment. We assessed AR and IOP before and after the driving session, and also collected subjective measures of arousal and fatigue. We found that IOP and AR decreased (i.e., the accommodative lag increased) after the driving session (p=0.03 and p<0.001, respectively). Moreover, the nearest distances tested (20cm, 25cm, and 33cm) induced the highest decreases in AR (corrected p-values<0.05). Consistent with these findings, the subjective levels of arousal decreased and levels of fatigue increased after the driving session (all p-values<0.001). These results represent an innovative step towards an objective, valid, and reliable assessment of fatigue-impaired driving based on visual fatigue signs. Copyright © 2016 Elsevier Inc. All rights reserved.

Statistical analysis plan for the Laser-1st versus Drops-1st for Glaucoma and Ocular Hypertension Trial (LiGHT): a multi-centre randomised controlled trial.

PubMed

Vickerstaff, Victoria; Ambler, Gareth; Bunce, Catey; Xing, Wen; Gazzard, Gus

2015-11-11

The LiGHT trial (Laser-1st versus Drops-1st for Glaucoma and Ocular Hypertension Trial) is a multicentre randomised controlled trial of two treatment pathways for patients who are newly diagnosed with open-angle glaucoma (OAG) and ocular hypertension (OHT). The main hypothesis for the trial is that lowering intraocular pressure (IOP) with selective laser trabeculoplasty (SLT) as the primary treatment ('Laser-1st') leads to a better health-related quality of life than for those started on IOP-lowering drops as their primary treatment ('Medicine-1st') and that this is associated with reduced costs and improved tolerability of treatment. This paper describes the statistical analysis plan for the study. The LiGHT trial is an unmasked, multi-centre randomised controlled trial. A total of 718 patients (359 per arm) are being randomised to two groups: medicine-first or laser-first treatment. Outcomes are recorded at baseline and at 6-month intervals up to 36 months. The primary outcome measure is health-related quality of life (HRQL) at 36 months measured using the EQ-5D-5L. The main secondary outcome is the Glaucoma Utility Index. We plan to analyse the patient outcome data according to the group to which the patient was originally assigned. Methods of statistical analysis are described, including the handling of missing data, the covariates used in the adjusted analyses and the planned sensitivity analyses. The trial was registered with the ISRCTN register on 23/07/2012, number ISRCTN32038223 .

Oral administration of an association of forskolin, rutin and vitamins B1 and B2 potentiates the hypotonising effects of pharmacological treatments in POAG patients.

PubMed

Pescosolido, N; Librando, A

2010-01-01

Control of intraocular pressure is still the main strategy to treat glaucoma patients. Forskolin has already shown an ability to control intraocular pressure after topic administration, whereas rutin is known to improve ocular blood fl ow. Therefore, aim of this pilot study has been to observe whether administration of an association of oral forskolin and rutin to POAG patients under different regimens of medical therapy may contribute to their effects, further decreasing IOP values. Forskolin (a natural compound present in the crude extract of the plant Coleus Forskohlii) and rutin are the main ingredients of a food supplement commercially available in Italy. In an open label pilot study, 16 patients with POAG under treatment with different topical drugs and with stable IOP were given additional treatment with the food supplement for 40 days, and their IOP values measured at enrolment, at the end of treatment and 40 days after treatment interruption. Further addition of forskolin and rutin to topical association treatments resulted in a further decrease of IOP by roughly 20% of the initial value. The effect was reversible upon suspension of the treatment. These data show for the fi rst time that forskolin and rutin given through the oral route appear to reach the ocular district, where they can act in synergy with topical pharmacological treatments, and contribute to the control of intraocular pressure.

A randomised crossover study comparing bimatoprost and latanoprost in subjects with primary angle closure glaucoma.

PubMed

How, A C S; Kumar, R S; Chen, Y-M; Su, D H; Gao, H; Oen, F T; Ho, C-L; Seah, S K; Aung, T

2009-06-01

To compare the intraocular pressure (IOP) lowering efficacy and side effects of latanoprost 0.005% and bimatoprost 0.03% in subjects with chronic primary angle closure glaucoma (PACG). This was an observer-masked randomised crossover study of 60 PACG subjects who received either latanoprost or bimatoprost for 6 weeks, after which they were crossed over to the other medication for another 6 weeks. The IOP-reducing effect of the medications was assessed by the reduction in IOP after 6 weeks of treatment compared with baseline. Fifty-four subjects (80 eyes) completed the study. Latanoprost reduced IOP (mean (SD)) by 8.4 (3.8) mm Hg and bimatoprost by 8.9 (3.9) mm Hg from a baseline of 25.2 (3.6) mm Hg and 25.2 (3.6) mm Hg respectively (p = 0.23). Adverse events were mild in both groups; however there were twice as many reports of an adverse event in the bimatoprost group (81%) compared with the latanoprost group (40%, p<0.01). Ocular irritation was the most frequently reported adverse event in both groups; 22 subjects (37.9%) treated with bimatoprost experienced ocular hyperaemia as compared with 13 subjects (22.4%) treated with latanoprost (p = 0.11). Bimatoprost once daily was similarly effective in reducing IOP compared with latanoprost once daily in subjects with chronic PACG. Both drugs were well tolerated with mild ocular adverse events.

Association of Systemic Medication Use With Intraocular Pressure in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study.

PubMed

Ho, Henrietta; Shi, Yuan; Chua, Jacqueline; Tham, Yih-Chung; Lim, Sing Hui; Aung, Tin; Wong, Tien Yin; Cheng, Ching-Yu

2017-03-01

There is limited understanding of the associations between systemic medication use and intraocular pressure (IOP) in the general population. To examine the association between systemic medication use and IOP in a multiethnic Asian population. In this post hoc analysis of the Singapore Epidemiology of Eye Diseases study, a population-based study of 10 033 participants (78.7% response rate) from 3 racial/ethnic groups (Chinese [recruited from February 9, 2009, through December 19, 2011], Malays [recruited from August 16, 2004, though July 10, 2006], and Indians [recruited from May 21, 2007, through December 29, 2009]), participants with glaucoma, previous ocular surgery, or trauma and an IOP asymmetry greater than 5 mm Hg between eyes were excluded. Intraocular pressure was measured using Goldmann applanation tonometry. An interviewer-administered questionnaire was conducted to collect data on medication and other variables. Data analysis was performed from August 1 through October 31, 2015. Associations between medication and IOP were assessed using linear regression models adjusted for age, sex, body mass index, ethnicity, and the medical condition for which the medication was taken (angiotensin-converting enzyme inhibitors [ACEIs], angiotensin receptor blockers [ARBs], and β-blockers adjusted for blood pressure, statins adjusted for lipids, and biguanides, sulfonylureas, α-glycosidase inhibitors [AGIs], and insulin adjusted for glycosylated hemoglobin). Medications associated with significant IOP differences were incorporated into regression models adjusted for concomitant use of multiple medications. Generalized estimating equation models were used to account for correlation between eyes. Of the 10 033 participants, we analyzed 8063 (mean [SD] age, 57.0 [9.6] years; 4107 female [50.9%]; 2680 Chinese [33.2%], 2757 Malay [34.2%], and 2626 Indian [32.6%] individuals). Systemic β-blocker use was independently associated with an IOP of 0.45 mm Hg lower (95% CI

The arguments for and against cannabinoids application in glaucomatous retinopathy.

PubMed

Panahi, Yunes; Manayi, Azadeh; Nikan, Marjan; Vazirian, Mahdi

2017-02-01

Glaucoma represents several optic neuropathies leading to irreversible blindness through progressive retinal ganglion cell (RGC) loss. Reduction of intraocular pressure (IOP) is known as the only modifiable factor in the treatment of this disorder. Application of exogenous cannabinoids to lower IOP has attracted attention of scientists as potential agents for the treatment of glaucoma. Accordingly, neuroprotective effect of these agents has been recently described through modulation of endocannabinoid system in the eye. In the present work, pertinent information regarding ocular endocannabinoid system, mechanism of exogenous cannabinoids interaction with the ocular endocannabinoid system to reduce IOP, and neuroprotection property of cannabinoids will be discussed according to current scientific literature. In addition to experimental studies, bioavailability of cannabinoids, clinical surveys, and adverse effects of application of cannabinoids in glaucoma will be reviewed. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Intra-articular pressures and joint mechanics: should we pay attention to effusion in knee osteoarthritis?

PubMed

Rutherford, Derek James

2014-09-01

What factors play a role to ensure a knee joint does what it should given the demands of moving through the physical environment? This paper aims to probe the hypothesis that intra-articular joint pressures, once a topic of interest, have been left aside in contemporary frameworks in which we now view knee joint function. The focus on ligamentous deficiencies and the chondrocentric view of osteoarthritis, while important, have left little attention to the consideration of other factors that can impair joint function across the lifespan. Dynamic knee stability is required during every step we take. While there is much known about the role that passive structures and muscular activation play in maintaining a healthy knee joint, this framework does not account for the role that intra-articular joint pressures may have in providing joint stability during motion and how these factors interact. Joint injuries invariably result in some form of intra-articular fluid accumulation. Ultimately, it may be how the knee mechanically responds to this fluid, of which pressure plays a significant role that provides the mechanisms for continued function. Do joint pressures provide an important foundation for maintaining knee function? This hypothesis is unique and argues that we are missing an important piece of the puzzle when attempting to understand implications that joint injury and disease have for joint function. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of high pressurization versus normal pressurization on changes in intraocular pressure immediately after clear corneal cataract surgery.

PubMed

Hayashi, Ken; Yoshida, Motoaki; Manabe, Shin-Ichi; Yoshimura, Koichi

2014-01-01

To compare changes in intraocular pressure (IOP) immediately after clear corneal incision (CCI) cataract surgery between eyes in which IOP was adjusted to a high or normal range at the conclusion of surgery. Hayashi Eye Hospital, Fukuoka, Japan. Comparative case series. Either eye of patients scheduled for phacoemulsification was randomized to 1 of 2 groups as follows: eyes that were to be adjusted to (1) high IOP (22 to 40 mm Hg) or (2) normal IOP (10 to 21 mm Hg). The IOP was measured using a rebound tonometer preoperatively; at the conclusion of surgery; and 15, 30, 60, 120, and 180 minutes and 24 hours postoperatively. The Seidel test and anterior segment optical coherence tomography (AS-OCT) were performed. The mean IOP at the conclusion of surgery was 31.3 mm Hg in the high IOP group and 17.1 mm Hg in the normal IOP group. The IOP decreased to approximately 15 mm Hg by 15 minutes and did not change until 60 minutes in either group. The mean IOP did not differ significantly between groups throughout the observation period (P ≥.0634). Hypotony of 5 mm Hg or less was not detected in any eye. The Seidel test was negative and based on AS-OCT, the wound was closed at 60 minutes in all eyes. After adjusting IOP to a high or normal range, the IOP normalized within 15 minutes postoperatively and was stable for 24 hours. The wound was closed within 60 minutes postoperatively. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

[CANNABIS AND GLAUCOMA: AN ANCIENT LEGEND OR A NOVEL THERAPEUTIC HORIZON?].

PubMed

Mathalone, Nurit; Wolf, Alvit; Geyer, Orna

2015-06-01

Glaucoma causes damage to the optic nerve and compromises the visual field. The main risk factor of the disease is the level of the intra-ocular pressure. Therapeutic options include medical and surgical treatment, aimed to lower the intra-ocular pressure. Consumption of the cannabis plant (Cannabis Satival has been known since ancient times. It can be consumed orally, topically, intra-venous or by inhalation. The main active ingredient of cannabis is THC (Tetra-Hydro-Cannabinol). One of THC's reported effects is the reduction of intra-ocular pressure. Several studies have demonstrated temporary intra-ocular pressure decrease in both healthy subjects and glaucoma patients following topical application or systemic consumption. The effect was a short term one. It was followed by the development of resistance to the drug after prolonged intake and it was also accompanied by topical and systemic side effects. Cannabis may be considered as a therapeutic option in glaucoma. Its limited effect, development of resistance, acquired side effects and the accompanying psycho-active influence limit its advantage and cause its efficacy to be dubious. Therefore, cannabis treatment for glaucoma currently seems impractical and is not recommended by either the Israeli or the American glaucoma societies.

[Pressure-reducing effect of latanoprost 0.005%].

PubMed

Albach, C; Wachsmuth, E D; Velte, K; Dekker, P; Robert, Y

1998-05-01

Earlier studies in monkeys have shown that latanoprost 0.005% lowers the IOP by improving the uveoscleral Outflow. We wanted to know if this is also the case in the human eye. We used our new aqueous humor outflow test with 2-nitrophenyl-acetate in 9 healthy human volunteers, mean age 32 +/- 8.3 years. They were measured before and 12 h after receiving one drop of latanoprost 0.005% in one eye, randomly chosen. The ocular Photometer was used to quantify the disappearance of the dye out of the anterior chamber. The half-life time of the dye is shortened after latanoprost 0.005%. It is significantly correlated to the pressure lowering effect of latanoprost 0.005% (r2 = 0.5968). The dye-dilution technique proves that latanoprost 0.005% influences the outflow of the human eye. The better the outflow, the greater the pressure drop in the eye. The experiment nicely shows that photometric quantification of 2-nitrophenyl-acetate is a simple, reliable test for the knowledge of the aqueous humor outflow.

New intraocular pressure measurement method using reflected pneumatic pressure from cornea deformed by air puff of ring-type nozzle.

PubMed

Kim, Hyung Jin; Seo, Yeong Ho; Kim, Byeong Hee

2017-01-01

In this study, a non-contact type intraocular pressure (IOP) measuring system using reflected pneumatic pressure is proposed to overcome the disadvantages of existing measurement systems. A ring-type nozzle, a key component in the proposed system, is designed via computational fluid analysis. It predicts the reflected pneumatic pressure based on the nozzle exit angle and inner and outer diameters of the nozzle, which are 30°, 7 mm, and 9 mm, respectively. Performance evaluation is conducted using artificial eyes fabricated using polydimethylsiloxane with the specifications of human eyes. The IOP of the fabricated artificial eyes is adjusted to 10, 30, and 50 mm Hg, and the reflected pneumatic pressure is measured as a function of the distance between the ring-type nozzle and artificial eye. The measured reflected pneumatic pressure is high when the measurement distance is short and eye pressure is low. The cornea of an artificial eye is significantly deformed at a low IOP, and the applied pneumatic pressure is more concentrated in front of the ring-type nozzle because of the deformed cornea. Thus, the reflected pneumatic pressure at a low IOP has more inflows into the pressure sensor inserted inside the nozzle. The sensitivity of the output based on the IOP at measurement distances between 3-5 mm is -0.0027, -0.0022, -0.0018, -0.0015, and -0.0012. Sensitivity decreases as the measurement distance increases. In addition, the reflected pneumatic pressure owing to the misalignment at the measurement distances of 3-5 mm is not affected within a range of 0.5 mm. Therefore, the measurement range is acceptable up to a 1 mm diameter from the center of an artificial eye. However, the accuracy gradually decreases as the reflected pneumatic pressure from a misalignment of 1 mm or more decreases by 26% or more.

New intraocular pressure measurement method using reflected pneumatic pressure from cornea deformed by air puff of ring-type nozzle

PubMed Central

Kim, Hyung Jin; Seo, Yeong Ho

2017-01-01

In this study, a non-contact type intraocular pressure (IOP) measuring system using reflected pneumatic pressure is proposed to overcome the disadvantages of existing measurement systems. A ring-type nozzle, a key component in the proposed system, is designed via computational fluid analysis. It predicts the reflected pneumatic pressure based on the nozzle exit angle and inner and outer diameters of the nozzle, which are 30°, 7 mm, and 9 mm, respectively. Performance evaluation is conducted using artificial eyes fabricated using polydimethylsiloxane with the specifications of human eyes. The IOP of the fabricated artificial eyes is adjusted to 10, 30, and 50 mm Hg, and the reflected pneumatic pressure is measured as a function of the distance between the ring-type nozzle and artificial eye. The measured reflected pneumatic pressure is high when the measurement distance is short and eye pressure is low. The cornea of an artificial eye is significantly deformed at a low IOP, and the applied pneumatic pressure is more concentrated in front of the ring-type nozzle because of the deformed cornea. Thus, the reflected pneumatic pressure at a low IOP has more inflows into the pressure sensor inserted inside the nozzle. The sensitivity of the output based on the IOP at measurement distances between 3–5 mm is -0.0027, -0.0022, -0.0018, -0.0015, and -0.0012. Sensitivity decreases as the measurement distance increases. In addition, the reflected pneumatic pressure owing to the misalignment at the measurement distances of 3–5 mm is not affected within a range of 0.5 mm. Therefore, the measurement range is acceptable up to a 1 mm diameter from the center of an artificial eye. However, the accuracy gradually decreases as the reflected pneumatic pressure from a misalignment of 1 mm or more decreases by 26% or more. PMID:29216189

Protecting the retinal neurons from glaucoma: lowering ocular pressure is not enough.

PubMed

Pascale, Alessia; Drago, Filippo; Govoni, Stefano

2012-07-01

The retina is theater of a number of biochemical reactions allowing, within its layers, the conversion of light impulses into electrical signals. The axons of the last neuronal elements, the ganglion cells, form the optic nerve and transfer the signals to the brain. Therefore, an appropriate cellular communication, not only within the different retinal cells, but also between the retina itself and the other brain structures, is fundamental. One of the most diffuse pathologies affecting retinal function and communication, which thus reverberates in the whole visual system, is glaucoma. This insidious disease is characterized by a progressive optic nerve degeneration and sight loss which may finally lead to irreversible blindness. Nevertheless, the progressive nature of this pathology offers an opportunity for therapeutic intervention. To better understand the cellular processes implicated in the development of glaucoma useful to envision a targeted pharmacological strategy, this manuscript first examines the complex cellular and functional organization of the retina and subsequently identifies the targets sensitive to neurodegeneration. Within this context, high ocular pressure represents a key risk factor. However, recent literature findings highlight the concept that lowering ocular pressure is not enough to prevent/slow down glaucomatous damage, suggesting the importance of combining the hypotensive treatment with other pharmacological approaches, such as the use of neuroprotectants. Therefore, this important and more novel aspect is extensively considered in this review, also emphasizing the idea that the neuroprotective strategy should be extended to the entire visual system and not restricted to the retina. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hypobaric hypoxia: effects on intraocular pressure and corneal thickness.

PubMed

Nebbioso, Marcella; Fazio, Stefano; Di Blasio, Dario; Pescosolido, Nicola

2014-01-01

The purpose of this study focused on understanding the mechanisms underlying ocular hydrodynamics and the changes which occur in the eyes of subjects exposed to hypobaric hypoxia (HH) to permit the achievement of more detailed knowledge in glaucomatous disease. Twenty male subjects, aged 32±5 years, attending the Italian Air Force, were enrolled for this study. The research derived from hypobaric chamber, using helmet and mask supplied to jet pilotes connected to oxygen cylinder and equipped with a preset automatic mixer. The baseline values of intraocular pressure (IOP), recorded at T1, showed a mean of 16±2.23 mmHg, while climbing up to 18,000 feet the mean value was 13.7±4.17 mmHg, recorded at T2. The last assessment was performed returning to sea level (T4) where the mean IOP value was 12.8±2.57 mmHg, with a significant change (P<0.05) compared to T1. Pachymetry values related to corneal thickness in conditions of hypobarism revealed a statistically significant increase (P<0.05). The data collected in this research seem to confirm the increasing outflow of aqueous humor (AH) in the trabecular meshwork (TM) under conditions of HH.

Hypobaric Hypoxia: Effects on Intraocular Pressure and Corneal Thickness

PubMed Central

Di Blasio, Dario; Pescosolido, Nicola

2014-01-01

Objective. The purpose of this study focused on understanding the mechanisms underlying ocular hydrodynamics and the changes which occur in the eyes of subjects exposed to hypobaric hypoxia (HH) to permit the achievement of more detailed knowledge in glaucomatous disease. Methods. Twenty male subjects, aged 32 ± 5 years, attending the Italian Air Force, were enrolled for this study. The research derived from hypobaric chamber, using helmet and mask supplied to jet pilotes connected to oxygen cylinder and equipped with a preset automatic mixer. Results. The baseline values of intraocular pressure (IOP), recorded at T1, showed a mean of 16 ± 2.23 mmHg, while climbing up to 18,000 feet the mean value was 13.7 ± 4.17 mmHg, recorded at T2. The last assessment was performed returning to sea level (T4) where the mean IOP value was 12.8 ± 2.57 mmHg, with a significant change (P < 0.05) compared to T1. Pachymetry values related to corneal thickness in conditions of hypobarism revealed a statistically significant increase (P < 0.05). Conclusions. The data collected in this research seem to confirm the increasing outflow of aqueous humor (AH) in the trabecular meshwork (TM) under conditions of HH. PMID:24550712

Intraocular Pressure Response to Moderate Exercise during 30-Min Recovery.

PubMed

Najmanova, Eliska; Pluhacek, Frantisek; Botek, Michal

2016-03-01

The aim of the study was to evaluate intraocular pressure (IOP) before and after moderate exercise in normal healthy individuals with defined physical exertion. The second aim of this investigation was to determine the correlation between resting IOP (IOPr) and its change induced by exercise as well as the relationship between resting heart rate (HRr) and changes in IOP after exercise. Forty-one healthy volunteers between the ages of 19 and 25 years were recruited for the study. First, the resting (reference) values IOPr and HRr were measured after 30 min of resting time. Volunteers consequently performed 30 min of exercise on a bicycle ergometer. Intraocular pressure was remeasured immediately after the end of exercise (the relevant IOP change was denoted as ΔIOP0) and subsequently repeated 5, 10, 20, and 30 min after exercise. A significant decrease in IOP compared with the resting value (post hoc Tukey honest significant difference test) was found immediately after exercise (p = 2 × 10) and 5 and 10 min after exercise (p = 2 × 10 and p = 3 × 10). Significant relationships were found between the change in IOP (ΔIOP0) and baseline IOP (IOPr) and between the baseline resting heart rate (HRr) and the change in IOP (ΔIOP0). There was a significant IOP-lowering effect, which was persistent for 10 min after 30 min of exercise. The IOP change was dependent on the initial IOP reading and initial HR.

Seasonal changes of 24-hour intraocular pressure rhythm in healthy Shanghai population

PubMed Central

Cheng, Jingyi; Xiao, Ming; Xu, Huan; Fang, Shaobin; Chen, Xu; Kong, Xiangmei; Sun, Xinghuai

2016-01-01

Abstract The aim of the present study was to investigate and compare the 24-hour intraocular pressure (IOP) rhythms in winter and summer in the healthy population of Shanghai, China. This is a cross-sectional study in which 24-hour IOP measurements were taken for all eligible healthy volunteers in winter and summer, respectively, and the temperature, hours of sunlight (sunlight time), and circulatory parameters, including heart rate, systolic blood pressure, and diastolic blood pressure, were also recorded. The 24-hour IOP curves and IOP parameters (mean, peak, trough, and fluctuation of IOP together with the diurnal-to-nocturnal IOP change) in winter and summer were obtained and compared. The magnitude of IOP changes from summer to winter was also calculated. A total of 29 participants (58 eyes), 14 (48.28%) male and 15 (51.72%) female, aged 43.66 ± 12.20 (19–61) years, were considered eligible for this study. Generally, IOP decreased progressively before noon, increased notably in the nocturnal period, and peaked at 12:00 am in winter and at 2:00 am in summer. The pattern of 24-hour IOP in winter and summer was significantly different (P = 0.002). The average IOPs from 4:00 pm to 8:00 am, except for 6:00 am, were significantly higher in winter (P < 0.05). However, no significant differences were shown after adjusting for temperature and/or sunlight time. From summer to winter, the extent of IOP increase was mostly around 0 to 3 mm Hg, and the IOPs increased more significantly in the nocturnal period than in the diurnal period (P = 0.05). The 24-hour IOP rhythms were different in winter and summer, with higher IOP level in winter. Temperature and sunlight time, which are independent of heart rate and blood pressure, affected the 24-hour IOP rhythms in healthy people in Shanghai, China. Further investigations are expected for the rhythm of some endogenous substance secretion and the inner mechanism of regulation of IOP. PMID:27495076

The impact of intraocular pressure on elastic wave velocity estimates in the crystalline lens.

PubMed

Park, Suhyun; Yoon, Heechul; Larin, Kirill V; Emelianov, Stanislav Y; Aglyamov, Salavat R

2016-12-20

Intraocular pressure (IOP) is believed to influence the mechanical properties of ocular tissues including cornea and sclera. The elastic properties of the crystalline lens have been mainly investigated with regard to presbyopia, the age-related loss of accommodation power of the eye. However, the relationship between the elastic properties of the lens and IOP remains to be established. The objective of this study is to measure the elastic wave velocity, which represents the mechanical properties of tissue, in the crystalline lens ex vivo in response to changes in IOP. The elastic wave velocities in the cornea and lens from seven enucleated bovine globe samples were estimated using ultrasound shear wave elasticity imaging. To generate and then image the elastic wave propagation, an ultrasound imaging system was used to transmit a 600 µs pushing pulse at 4.5 MHz center frequency and to acquire ultrasound tracking frames at 6 kHz frame rate. The pushing beams were separately applied to the cornea and lens. IOP in the eyeballs was varied from 5 to 50 mmHg. The results indicate that while the elastic wave velocity in the cornea increased from 0.96  ±  0.30 m s -1 to 6.27  ±  0.75 m s -1 as IOP was elevated from 5 to 50 mmHg, there were insignificant changes in the elastic wave velocity in the crystalline lens with the minimum and the maximum speeds of 1.44  ±  0.27 m s -1 and 2.03  ±  0.46 m s -1 , respectively. This study shows that ultrasound shear wave elasticity imaging can be used to assess the biomechanical properties of the crystalline lens noninvasively. Also, it was observed that the dependency of the crystalline lens stiffness on the IOP was significantly lower in comparison with that of cornea.

Ocular manifestations of gravity inversion.

PubMed

Friberg, T R; Weinreb, R N

To determine the ocular manifestations of inverting the human body into a head-down vertical position, we evaluated normal volunteers with applanation tonometry, fundus photography, fluorescein angiography, and ophthalmodynamometry. Compared with data obtained in the sitting position, the intraocular pressure more than doubled on inversion (35.6 +/- 4 v 14.1 +/- 2.8 mm Hg, n = 16), increasing to levels well within the glaucomatous range. Pressures in the central retinal artery underwent similar increases, while the caliber of the retinal arterioles decreased substantially. External ocular findings associated with gravity inversion included orbital congestion, conjunctival hyperemia, petechiae of the eyelids, excessive tearing (epiphora), and subconjunctival hemorrhage. We suggest that patients with retinal vascular abnormalities, macular degeneration, ocular hypertension, glaucoma, and similar disorders refrain from inversion altogether. Whether normal individuals will suffer irreversible damage from inversion is uncertain, but it seems prudent to recommend that prolonged periods of inverted posturing be avoided.

Clinical research on intravitreal injection of bevacizumab in the treatment of macula lutea and retinal edema of ocular fundus disease.

PubMed

Yan, Ying; Wang, Tao; Cao, Jing; Wang, Meng; Li, Fenghua

2015-07-01

This paper aimed to explore clinically curative effect of intravitreal injection of bevacizumab in the treatment of macula lutea and retinal edema of ocular fundus disease. The number of 300 patients (390 eyes) with ocular fundus diseases including retinal vein occlusion (RVO), diabetic retinopathy (DR), age-related macular degeneration (ARMD), central serous chorioretinopathy (CSC), choridal new vessel (CNV) received and cured in the hospital from February 2010 to February 2014 were given intravitreal injection of bevacizumab (1.5mg) with once per month and a total of 2-3 times. Results of patients' vision and fluorescence fundus angiography (FFA), optical coherence tomography (OCT) before and after treatment were compared and curative effects were evaluated. Vision of 349 eyes (89.49%) improved obviously with the average of more than 2 lines, patient's intraocular pressure (IOP) was normal and all indexes were clearly better; vision of 26 eyes (6.67%) was stable before the treatment and without any changes after the treatment, the situation of fundus got better without increased IOP; vision of 15 eyes (3.85%) decreased to some extent, and the symptoms eased slightly after symptomatic treatment. In the 1st day after intravitreal injection, best-corrected visual acuity increased to 0.239±0.175, best-corrected visual acuity in 1 m was 0.315±0.182, in 3m continuously climbed to 0.350±0.270, and in 6 m was 0.362±0.282. Compared with vision before injection, t value was t=3.184, t=7.213, t=9.274 and t=9.970 (P=0.002, P=0.000, P=0.000 and P=0.000) respectively, and all P were less than 0.01. Furthermore, the difference was significant if a=0.01, which could confirm that 1m best corrected visual acuity of patients after intravitreal injection improved clearly in combination with before injection and 3m and 6 m visions enhanced constantly after injection. To sum up, intravitreal injection of bevacizumab in treating ocular fundus disease improves patient's vision

Tyrosine triple mutated AAV2-BDNF gene therapy in a rat model of transient IOP elevation

PubMed Central

Igarashi, Tsutomu; Kobayashi, Maika; Kameya, Shuhei; Fujimoto, Chiaki; Nakamoto, Kenji; Takahashi, Hisatomo; Igarashi, Toru; Miyake, Noriko; Iijima, Osamu; Hirai, Yukihiko; Shimada, Takashi; Okada, Takashi; Takahashi, Hiroshi

2016-01-01

Purpose We examined the neuroprotective effects of exogenous brain-derived neurotrophic factor (BDNF), which provides protection to retinal ganglion cells (RGCs) in rodents, in a model of transient intraocular pressure (IOP) elevation using a mutant (triple Y-F) self-complementary adeno-associated virus type 2 vector encoding BDNF (tm-scAAV2-BDNF). Methods The tm-scAAV2-BDNF or control vector encoding green fluorescent protein (GFP; tm-scAAV2-GFP) was intravitreally administered to rats, which were then divided into four groups: control, ischemia/reperfusion (I/R) injury only, I/R injury with tm-scAAV2-GFP, and tm-scAAV2-BDNF. I/R injury was then induced by transiently increasing IOP, after which the rats were euthanized to measure the inner retinal thickness and cell counts in the RGC layer. Results Intravitreous injection of tm-scAAV2-BDNF resulted in high levels of BDNF expression in the neural retina. Histological analysis showed that the inner retinal thickness and cell numbers in the RGC layer were preserved after transient IOP elevation in eyes treated with tm-scAAV2-BDNF but not in the other I/R groups. Significantly reduced glial fibrillary acidic protein (GFAP) immunostaining after I/R injury in the rats that received tm-scAAV2-BDNF indicated reduced retinal stress, and electroretinogram (ERG) analysis confirmed preservation of retinal function in the tm-scAAV2-BDNF group. Conclusions These results demonstrate the feasibility and effectiveness of neuroprotective gene therapy using tm-scAAV2-BDNF to protect the inner retina from transiently high intraocular pressure. An in vivo gene therapeutic approach to the clinical management of retinal diseases in conditions such as glaucoma, retinal artery occlusion, hypertensive retinopathy, and diabetic retinopathy thus appears feasible. PMID:27440998

Resident-performed Ex-PRESS shunt implantation versus trabeculectomy.

PubMed

Seider, Michael I; Rofagha, Soraya; Lin, Shan C; Stamper, Robert L

2012-09-01

To compare outcomes between resident-performed trabeculectomy and Ex-PRESS shunt implantation. A consecutive cohort of 36 Ex-PRESS shunt implantations and 57 trabeculectomies (1 eye/patient) performed by resident surgeons in their third year of ophthalmic training at the University of California, San Francisco and at the San Francisco Veterans Administration Hospital, under the supervision of a single glaucoma fellowship-trained surgeon were included in this study. Eyes with < 6 months of follow-up or previous glaucoma surgery were excluded. Preoperative and postoperative intraocular pressure (IOP), preoperative and postoperative number of ocular antihypertensive medications and complication rates were compared between the 2 procedures retrospectively. No difference was found in postoperative IOP (all, P≥0.099) or proportional decrease in IOP (all, P≥0.092) between the trabeculectomy and Ex-PRESS shunt groups at all follow-up points. On average, the Ex-PRESS shunt group required significantly less ocular antihypertensive medication to control IOP at 3 months postoperative (P=0.01), but no difference was found at 6 months or 1 year (all, P≥0.28). A larger proportion of Ex-PRESS shunt patients had good IOP control without medication at 3 (P=0.057) and 6 months (P=0.076) postoperatively. No difference was found in the rates of sight-threatening complications between groups (all, P≥0.22). In the hands of ophthalmology residents in their third year of training, the trabeculectomy and Ex-PRESS shunt implantation procedures perform comparably in terms of postoperative IOP control, reduction in patient dependence on ocular antihypertensive medications, and risk of complication in our population.

Effect of Laser in Situ Keratomileusis on Schiøtz, Goldmann, and Dynamic Contour Tonometric Measurements.

PubMed

Sales-Sanz, Marco; Arranz-Marquez, Esther; Piñero, David P; Arruabarrena, Carolina; Mikropoulos, Dimitrios G; Teus, Miguel A

2016-04-01

To assess the effect of laser in situ keratomileusis (LASIK) on ocular rigidity and compare its effect on intraocular pressure (IOP) readings with Goldmann applanation tonometry (GAT), Schiøtz indentation tonometry (ST), and dynamic contour tonometry (DCT). Prospective, observational, single-masked study. Eighty-one patients who underwent myopic LASIK and 108 unoperated myopic control patients were included in the study. The IOP was measured using GAT, DCT, and ST. The coefficient of ocular rigidity (Ko) was obtained from the regression analysis of the 3 readings obtained with each weight of the ST. Linear multiple regression analysis was performed with dummy variables to assess the effects of age, central corneal thickness (CCT), and refractive surgery on measured IOP values. Age, CCT, and previous LASIK explained 39.41% of the IOP readings with GAT, 25.31% with DCT, and 3.28% with ST. LASIK caused a mean decrease of -2.51 mm Hg in IOP readings (P=0.000) with GAT, -1.29 mm Hg (P=0.036) with DCT, and no significant change in IOP readings with ST (P=0.299). Significant differences in the Ko were observed between the LASIK and control groups. The Ko values were unrelated to age and CCT in the LASIK and control groups. ST seems to be less affected by previous LASIK procedures. There is a difference in the ocular rigidity between the unoperated and LASIK eyes that is not correlated with the CCT. Therefore, ST seems to measure changes in the biomechanical behavior of corneas that underwent LASIK surgery.

Effect of the Age Cross-Link Breaker Alagebrium on Anterior Segment Physiology, Morphology, and Ocular Age and Rage

PubMed Central

Kiland, Julie A.; Gabelt, B’Ann T.; Tezel, Gülgün; Lütjen-Drecoll, Elke; Kaufman, Paul L.

2009-01-01

Purpose: To determine the effects of the advanced glycation end product (AGE) cross-link breaker alagebrium on intraocular pressure (IOP), accommodation (ACC), outflow facility (OF), anterior segment morphology, and ocular AGE and receptors for AGE (RAGE) in older rhesus monkeys. Methods: Six rhesus monkeys (aged 19 to 20 years) received 3 or 4 intracameral and intravitreal (final concentration, 1 mM) injections of alagebrium to one eye over 2.5 to 3 weeks and vehicle to the opposite eye. ACC and OF responses to intramuscular or intravenous pilocarpine were measured at baseline and at 1 to 2 weeks and 2, 4, and 6 months postinjection. IOP was measured prior to all injections, ACC, and OF measurements. Monkeys were euthanized 3 to 6 months after the last injection, the eyes were enucleated, and anterior and posterior segments were examined by electron microscopy or immunohistochemistry. Results: No significant differences were found in ACC or IOP at any time point after alagebrium treatment. Baseline OF was higher (37.0 ± 6.0%; P ≤ .005) in alagebrium-treated vs control eyes at 6 months postinjection. In 3 monkeys, alagebrium-treated eyes, compared to control eyes, showed greater focal plaque formation, similar to that seen in primary open-angle glaucoma, in the juxtacanalicular meshwork/inner wall of Schlemm’s canal. No changes in anterior segment AGE or RAGE were detectable. However, some areas of the retina and optic nerve head exhibited decreased AGE and increased RAGE immunostaining. Conclusions: Intraocular injection of AGE cross-link breakers is an unlikely approach for glaucoma therapy. However, it may generate a model for further study of glaucomatous-like plaque formation. Immunohistochemical changes in the posterior segment in response to alagebrium warrant further functional studies. PMID:20126491

Intra-arterial chemotherapy for the management of retinoblastoma: four-year experience.

PubMed

Gobin, Y Pierre; Dunkel, Ira J; Marr, Brian P; Brodie, Scott E; Abramson, David H

2011-06-01

To determine whether intra-arterial chemotherapy is safe and effective in advanced intraocular retinoblastoma. Retinoblastoma often presents with advanced intraocular disease and, despite conventional treatment with intravenous chemotherapy and external beam radiation therapy, may still require enucleation. Single-arm, prospective registry from May 30, 2006, to May 30, 2010, at an ophthalmic oncology referral center with ambulatory care. A total of 95 eyes of 78 patients with unilateral or bilateral retinoblastoma were treated. The intervention was selective catheterization of the ophthalmic artery and injection of chemotherapy, usually melphalan with or without topotecan. Drug dosage was determined by age and angioanatomy. The main outcome measures were procedural success, event-free (enucleation or radiotherapy) ocular survival, and ocular and extraocular complications. Catheterization succeeded in 98.5% of procedures. There were 289 chemotherapy injections (median, 3 per eye). The Kaplan-Meier estimates of ocular event-free survival rates at 2 years were 70.0% (95% confidence interval, 57.9%-82.2%) for all eyes, 81.7% (95% confidence interval, 66.8%-96.6%) for eyes that received intra-arterial chemotherapy as primary treatment, and 58.4% (95% confidence interval, 39.5%-77.2%) for eyes that had previous treatment failure with intravenous chemotherapy and/or external beam radiation therapy. There were no permanent extraocular complications. Our experience suggests that intra-arterial chemotherapy is safe and effective in the treatment of advanced intraocular retinoblastoma.

The vascular basis of the positional influence of the intraocular pressure.

PubMed

Krieglstein, G K; Waller, W K; Leydhecker, W

1978-05-02

By measuring intraocular pressure in different body positions from 60 degrees semiupright to 30 degrees head down, a nonlinear relationship between IOP increase and body position was confirmed. IOP postural response in individual subjects was roughly correlated to ophthalmic arterial pressure and to the episcleral venous pressure postural response. In one series of subjects, the episcleral venous pressure increments due to posture wa; parallel to the applanation-indentation disparity in the same individual eyes. Differential tonometry with applanation or indentation procedures under blind conditions gave significantly low indentation readings. It is concluded that IOP postural response depends on arterial and venous vascular changes when subjects move from an erect to a horizontal body position. Blood expulsion from the choroid by indentation tonometry might be the reason that this tonometric procedure does not measure IOP changes based on vascular changes.

The efficacy of Ahmed glaucoma valve drainage devices in cases of adult refractory glaucoma in Indian eyes

PubMed Central

Parihar, Jitendra K S; Vats, Devendra P; Maggon, Rakesh; Mathur, Vijay; Singh, Anirudh; Mishra, Sanjay K

2009-01-01

Aim: To evaluate the efficacy of Ahmed glaucoma valve (AGV) drainage devices in cases of adult refractory glaucoma in Indian eyes. Settings and Design: Retrospective interventional case series study. Materials and Methods: Fifty two eyes of 32 patients of refractory glaucoma in the age group of 35 to 60 years who underwent AGV implantation with or without concomitant procedures from January 2003 to Jan 2007 were studied. Of these, 46 eyes (88%) had undergone filtering surgery earlier whereas remaining eyes underwent primary AGV implantation following failure of maximal medical therapy. The follow up ranged between 12 months to 48 months Results: Eighteen eyes (35%) had undergone phacoemulsification with AGV implantation, penetrating keratoplasty (PK) with AGV and intraocular lens (IOL) implantation in 13 eyes (25%), AGV over preexisting IOL in eight eyes (15%). AGV implantation alone was done in six (11%) eyes. Anterior chamber (AC) reconstruction with secondary IOL and AGV was performed in the remaining eyes. The mean intra ocular pressure (IOP) decreased from 36.3 ± 15.7 mm Hg to 19.6 ± 9.2 mm Hg. Complete success as per criteria was achieved in 46 eyes (88%). None of the eyes had failure to maintain IOP control following AGV. Conclusion: The AGV resulted in effective and sustained control of IOP in cases of adult refractory glaucoma in intermediate follow up. PMID:19700871

The evaluation of the effect of body positioning on intra-abdominal pressure measurement and the effect of intra-abdominal pressure at different body positioning on organ function and prognosis in critically ill patients.

PubMed

Yi, Min; Leng, Yuxin; Bai, Yu; Yao, Gaiqi; Zhu, Xi

2012-04-01

Current literatures confirmed the widespread and frequent development of both intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) among the critically ill with a significant associated risk of organ failure and increased mortality. The 2004 International ACS Consensus Conference committee proposed that intra-abdominal pressure (IAP) be measured in complete supine position; however, the supine position of intensive care unit (ICU) patients (<30° of bed increase) presented a significant risk for ventilator-associated pneumonia. Therefore, the potential contribution of head of bed (HOB) position in elevating IAP should be considered. The purpose of this study was to evaluate the effect of body positioning on IAP measurement and the effect of IAP at different body positions on organ function and prognosis in critically ill patients. A prospective cohort study to investigate the effect of different patient positioning on IAP, organ function, and prognosis was conducted on 88 patients admitted to a medical-surgical ICU. On admission, patients' epidemiological data and risk factors for IAH were studied; daily mean IAPs, abdominal perfusion pressure, filtration gradient, Acute Physiology and Chronic Health Evaluation II score, sequential organ failure assessment score, and multiple organ dysfunction scores were registered; next, conventional hemodynamic variables, intrathoracic blood volume index, global end-diastolic volume index and extravascular lung water using the pulse contour cardiac output system were recorded. Intra-abdominal pressures were recorded through a bladder catheter every 4 hours on the first day. Intra-abdominal pressure was measured with the patient HOB increases from 0° to 45°. Mean arterial pressure was recorded simultaneously, whereas abdominal perfusion pressure and filtration gradient (FG) were also calculated simultaneously. The main results of this study were the incidence of IAH (28.4%) and ACS (2.3%) in ICU patients

Correlation Between Corneal Button Size and Intraocular Pressure During Femtosecond Laser-Assisted Keratoplasty.

PubMed

Choi, Mihyun; Lee, Yong Eun; Whang, Woong-Joo; Yoo, Young-Sik; Na, Kyung-Sun; Joo, Choun-Ki

2016-03-01

To evaluate changes in intraocular pressure (IOP) in recipient and donor eyes during femtosecond laser-assisted keratoplasty (FLAK) and to assess for differences in the diameter of trephinated corneal buttons according to changes in pressure. Twenty porcine whole eyes (recipient model) and 20 porcine-corneoscleral rims (donor model) were prepared, and anterior chamber pressures were measured using a fiberoptic sensing device (Opsens, Quebec, Canada) during the femtosecond laser corneal cutting process. To determine the diameter of corneal buttons, 10 porcine whole eyes (recipient model) and 12 corneoscleral rims (donor model) of each baseline IOP were cut with the femtosecond laser programmed to the following pattern: "vertical side cut"; 1200 μm (depth), 8 mm (diameter). Digital photographs were obtained using microscopy and subsequently analyzed. The IOP (mean ± SD) for the recipient model was 10.2 (±0.9) mm Hg at baseline and ranged from 96.6 (±4.5) to ∼138.4 (±3.8) mm Hg during the corneal cutting process. This shows that the maximum IOP during FLAK increased 13.5 times compared with baseline. In the donor model, the mean pressure elevation from baseline artificial anterior chamber (AAC) pressure to corneal cutting was 15.8 (±5.4) mm Hg. This showed a positive correlation with baseline IOP [correlation coefficient (CC) = 0.827, P = 0.006]. As the baseline IOP in the recipient eye increased, trephinated corneal button size was reduced by up to 3.9% in diameter (CC = -0.945, P = 0.015). In addition, in donor eyes, the diameter was decreased by up to 11.7% as the baseline AAC pressure increased (CC = -0.934, P = 0.006). During the FLAK procedure, the IOP increases in both recipient and donor eyes. The diameter of the trephinated donor and recipient corneal buttons was decreased as the initial baseline IOP increased. Ophthalmic surgeons can determine the AAC pressure based on the baseline IOP in the recipient patient.

Efficacy and Tolerability of Travoprost 0.004%/Timolol 0.5% Fixed-Dose Combination for the Treatment of Primary Open-Angle Glaucoma or Ocular Hypertension Inadequately Controlled with Beta-Blocker Monotherapy.

PubMed

Lerner, Simon Fabian; Park, Ki Ho; Hubatsch, Douglas A; Erichev, Valeriy; Paczka, Jose A; Roberts, Timothy V

2017-01-01

Objective . To evaluate the efficacy and tolerability of travoprost 0.004%/timolol 0.5% fixed-dose combination (TTFC) in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) inadequately controlled on beta-blocker monotherapy. Methods . In this phase IV, open-label study, 156 patients on beta-blocker monotherapy with mean intraocular pressure (IOP) between 18 and 32 mmHg were randomized (no washout period) to receive TTFC for 8 weeks (TTFC group) or to continue beta-blocker monotherapy for 4 weeks followed by TTFC for the remaining 4 weeks (beta-blocker group). Results . The mean IOP (±standard deviation) at baseline in the TTFC and beta-blocker groups was 22.5 ± 2.5 mmHg and 22.2 ± 2.3 mmHg, respectively, and at weeks 4 and 8, was 16.7 ± 3.1 mmHg and 16.1 ± 3.1 mmHg, respectively, in TTFC group and 21.1 ± 3.1 mmHg and 16.1 ± 2.8 mmHg, respectively, in the beta-blocker group. There was a significant least squares mean difference between TTFC and beta-blocker in 8 a.m. IOP at week 4 (-4.6 mmHg; one-sided 95% confidence interval [-inf, -3.9]; p < 0.0001 [primary endpoint]); the upper bound of the 95% confidence interval was within the prespecified limit (<0). Both treatments were well tolerated. Conclusion . Superior IOP control was achieved with TTFC in patients with OAG or OHT previously uncontrolled with beta-blockers. No new safety findings were identified. This trial is registered with ClinicalTrials.gov NCT02003391.

A comparative study of a preservative-free latanoprost cationic emulsion (Catioprost) and a BAK-preserved latanoprost solution in animal models.

PubMed

Daull, Philippe; Buggage, Ronald; Lambert, Grégory; Faure, Marie-Odile; Serle, Janet; Wang, Rong-Fang; Garrigue, Jean-Sébastien

2012-10-01

Benzalkonium chloride (BAK), a common preservative in eye drops, can induce ocular surface toxicity that may decrease glaucoma therapy compliance. The ocular hypotensive effect, pharmacokinetic (PK) profiles, and local tolerance of a preservative-free latanoprost 0.005% cationic emulsion (Catioprost(®)), and a BAK-preserved latanoprost 0.005% solution (Xalatan(®)), were compared. The ocular hypotensive effect was evaluated in monkeys with elevated intraocular pressure (IOP) induced by laser photocoagulation of the trabecular meshwork. Each monkey (n=8) received both latanoprost formulations once daily for 5 consecutive treatment days in a crossover design with at least a 2-week washout period between treatments. IOP was measured at baseline (on day 1, no instillation), on vehicle treatment day (day 0), and on treatment days 1, 3, and 5 before drug instillation and then hourly for 6 h. In rabbits, the ocular and systemic concentrations of latanoprost free acid were determined following a single instillation and the local tolerance of twice daily instillations over 28 days was assessed. Both the preservative-free and BAK-preserved latanoprost formulations shared the same efficacy profile with the maximum IOP reduction occurring 2 h after each morning dose (-15%, -20%, and -26%; -15%, -23%, and -23% on days 1, 3, and 5, respectively) and lasting through 24 h. The equivalence in efficacy was confirmed by the PK data demonstrating similar area under the curves (AUCs). While both formulations were well tolerated, the incidence of conjunctival hyperemia was reduced by 42% with the BAK-free latanoprost cationic emulsion. In animal models, a preservative-free latanoprost cationic emulsion was as effective as Xalatan(®) for lowering IOP with an improved ocular tolerance profile.

[Challenge and treatment strategy for ocular surface damage in patients with long term use of antiglaucoma drugs].

PubMed

He, Xiang-Ge

2011-02-01

Long term use of topical anti-glaucoma drugs has been shown to induce chronic conjunctivitis, superficial punctate keratitis (SPK) and dry eye symptom. Under these conditions, a loss of goblet cells in conjunctiva, epithelial squamous metaplasia and apoptosis were morphologically revealed. Benzalkonium Chloride (BKC), a most frequently used preservative in eye drops, has been found to be an important factor causing ocular surface damage. Furthermore, a big challenge for ophthalmologists is that toxic damage of medication to ocular surface tissues is mild, poor specificity, and delayed manifestation in patients, especially when coexisting with other ocular surface diseases. Impairment of ocular surface tissues greatly impacts the life quality of patients and subsequently influences compliance with glaucoma therapy. This paper emphasizes to take measures to prevent ocular surface tissue damage resulted from chronic use of topical anti-glaucoma drugs and further discusses the treatment strategy. Effective and long-lasting action drugs should always be selected for glaucomatous patients in order to decrease the frequency of topical instillation or at a more expensive medication, a fixed combination formula can be considered for glaucoma therapy. An early surgery or laser treatment is also proposed for the patients who require an IOP reduction with an existing ocular surface impairment. Future investigation and development of new medications with long-term efficacy and appropriate BKC are suggested and preservative-free or drugs with new preservative materials recommended.

Intraocular Pressure, Blood Pressure, and Retinal Blood Flow Autoregulation: A Mathematical Model to Clarify Their Relationship and Clinical Relevance

PubMed Central

Guidoboni, Giovanna; Harris, Alon; Cassani, Simone; Arciero, Julia; Siesky, Brent; Amireskandari, Annahita; Tobe, Leslie; Egan, Patrick; Januleviciene, Ingrida; Park, Joshua

2014-01-01

Purpose. This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. Methods. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. Results. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. Conclusions. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. PMID:24876284

Operational hydrological forecasting during the 2 IPHEx-IOP campaign – meet the challenge

USDA-ARS?s Scientific Manuscript database

An operational streamflow forecasting testbed was implemented during the Intense Observing Period (IOP) of the Integrated Precipitation and Hydrology Experiment (IPHEx-IOP) in May-June 2014 to characterize flood predictability skill in complex terrain and to investigate the propagation of uncertaint...

Cerebrospinal Fluid Pressure: Revisiting Factors Influencing Optic Nerve Head Biomechanics

PubMed Central

Hua, Yi; Voorhees, Andrew P.; Sigal, Ian A.

2018-01-01

Purpose To model the sensitivity of the optic nerve head (ONH) biomechanical environment to acute variations in IOP, cerebrospinal fluid pressure (CSFP), and central retinal artery blood pressure (BP). Methods We extended a previously published numerical model of the ONH to include 24 factors representing tissue anatomy and mechanical properties, all three pressures, and constraints on the optic nerve (CON). A total of 8340 models were studied to predict factor influences on 98 responses in a two-step process: a fractional factorial screening analysis to identify the 16 most influential factors, followed by a response surface methodology to predict factor effects in detail. Results The six most influential factors were, in order: IOP, CON, moduli of the sclera, lamina cribrosa (LC) and dura, and CSFP. IOP and CSFP affected different aspects of ONH biomechanics. The strongest influence of CSFP, more than twice that of IOP, was on the rotation of the peripapillary sclera. CSFP had similar influence on LC stretch and compression to moduli of sclera and LC. On some ONHs, CSFP caused large retrolamina deformations and subarachnoid expansion. CON had a strong influence on LC displacement. BP overall influence was 633 times smaller than that of IOP. Conclusions Models predict that IOP and CSFP are the top and sixth most influential factors on ONH biomechanics. Different IOP and CSFP effects suggest that translaminar pressure difference may not be a good parameter to predict biomechanics-related glaucomatous neuropathy. CON may drastically affect the responses relating to gross ONH geometry and should be determined experimentally. PMID:29332130

Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

PubMed

Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

2003-01-01

To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

Intraocular pressure measurements after conductive keratoplasty.

PubMed

Kymionis, George D; Naoumidi, Tatiana L; Aslanides, Ioannis M; Kumar, Vinod; Astyrakakis, Nikolaos I; Tsilimbaris, Miltiadis; Pallikaris, Ioannis G

2005-01-01

To determine the possible impact of conductive keratoplasty (CK) on intraocular pressure (IOP) measurements. A prospective, single-center, noncomparative interventional case series was performed. Baseline and postoperative IOPs were measured by Goldmann applanation tonometry in 32 eyes of 18 patients who underwent CK for hyperopia correction. Mean follow-up was 11.9 months (range: 8 to 18 months). After CK, a statistically significant decrease in the measured IOP was observed (before CK: 14.22+/-1.64 vs after CK: 12.66+/-2.21, P<.001). The change in IOP readings postoperatively was not correlated with age, sex, keratometric readings, or attempted correction. Despite the limitations due to the small number of patients enrolled in this study, the applanation tonometer appears to underestimate the true IOP after CK.

Methylphenidate (Ritalin)-associated cataract and glaucoma.

PubMed

Lu, Chao-Kung; Kuang, Tung-Mei; Chou, Joe Ching-Kuang

2006-12-01

Methylphenidate hydrochloride (Ritalin) is the drug of choice for attention deficit hyperactivity disorder (ADHD). However, an association of Ritalin with glaucoma has been reported. We report a case of Ritalin-associated cataract and glaucoma. A 10-year-old boy was diagnosed with ADHD and had received methylphenidate hydrochloride, 60 mg/day for 2 years. He presented with blurred vision. Best-corrected visual acuity was 6/60 in both eyes. Ocular examinations revealed intraocular pressure (IOP) of 30 mmHg under medication, dense posterior subcapsular opacity of lens, pale disc with advanced cupping, and marked constriction of visual field. Despite maximal anti-glaucomatous medication, IOP still could not be controlled. The patient then received combined cataract and glaucoma surgery. Visual acuity improved and IOP was within normal limits in both eyes postoperatively. Large dose of methylphenidate may cause cataract and glaucoma. The mechanism remains unclear. Doctors should be aware of the possible ocular side effects of methylphenidate.

Early aggressive intraocular pressure lowering, target intraocular pressure, and a novel concept for glaucoma care.

PubMed

Singh, Kuldev; Shrivastava, Anurag

2008-11-01

Early diagnosis of glaucomatous optic nerve damage offers the potential for early treatment which may prevent vision loss from this neurodegenerative disease. Even in patients who do not begin early treatment, early diagnosis allows for better monitoring of disease at a stage where the stakes are lower relative to later stages of the disease. For these reasons, early diagnosis of glaucomatous optic nerve disease is desirable and opens the door for appropriately aggressive therapy. The target intraocular pressure (IOP) concept is widely employed by glaucoma practitioners. Although there have been no randomized clinical trials or other high-quality studies showing the benefits of setting a target IOP versus not using this approach, there is ample evidence that lowering IOP slows glaucoma progression and, in general, lower is better, regardless of disease stage and baseline IOP level. We propose an alternative approach to managing glaucoma without the use of the target IOP concept and suggest that this market IOP concept should be compared with the target IOP approach in an appropriately powered comparative clinical trial.

Criteria for choosing clinically effective glaucoma treatment: A discussion panel consensus

PubMed Central

Thygesen, John; Burk, Reinhard; Carassa, Roberto; Crichton, Andrew; Goñi, Francisco Javier; Menage, Mitch; Miglior, Stefano; Montgomery, Donald; Nordmann, John-Philippe; Roberts, Tim; Singh, Kuldev

2007-01-01

Abstract Background: In the clinical management of patients at risk for or diagnosed with primary open-angle glaucoma (POAG), the aim of medical treatment is to reduce intraocular pressure (IOP) and then maintain it over time at a level that preserves both the structure and function of the optic nerve. Objective: The objective of this report was to establish a consensus on the criteria that should be used to determine the characteristics of IOP-lowering medication. Methods: Discussion was held among a panel of 12 physicians considered to be experts in glaucoma to develop a consensus on the criteria used by them to determine the characteristics of the IOP-lowering medication chosen for initial monotherapy and adjunctive treatment of ocular hypertension (OHT) or POAG. Consensus development combined available evidence and the impressions of these physicians regarding the clinical effectiveness of IOP-lowering medication for OHT and POAG. Once the panel identified the criteria, the order of priority and the relative importance of these criteria were then established in the setting of 3 risk categories (low, medium, and high) for a patient to experience significant visual disability from glaucoma over their expected life span. Results: The panel identified 5 criteria to determine the characteristics of IOP-lowering medication for OHT and POAG: IOP-lowering effect, systemic adverse events (AEs), ocular tolerability, compliance/administration, and cost of treatment. IOP-lowering effect was consistently ranked as the highest priority and cost as the lowest. The priority of compliance/administration did not vary by clinical situation. Systemic AEs and ocular tolerability were ranked as higher priorities in initial monotherapy than in adjunctive treatment and ranked lower as the risk for visual disability increased. The priority given to the criteria used to determine clinical effectiveness varied both with the risk for functional vision loss from glaucoma and whether

New method for remote and repeatable monitoring of intraocular pressure variations.

PubMed

Margalit, Israel; Beiderman, Yevgeny; Skaat, Alon; Rosenfeld, Elkanah; Belkin, Michael; Tornow, Ralf-Peter; Mico, Vicente; Garcia, Javier; Zalevsky, Zeev

2014-02-01

We present initial steps toward a new measurement device enabling high-precision, noncontact remote and repeatable monitoring of intraocular pressure (IOP)-based on an innovative measurement principle. Using only a camera and a laser source, the device measures IOP by tracking the secondary speckle pattern trajectories produced by the reflection of an illuminating laser beam from the iris or the sclera. The device was tested on rabbit eyes using two different methods to modify IOP: via an infusion bag and via mechanical pressure. In both cases, the eyes were stimulated with increasing and decreasing ramps of the IOP. As IOP variations changed the speckle distributions reflected back from the eye, data were recorded under various optical configurations to define and optimize the best experimental configuration for the IOP extraction. The association between the data provided by our proposed device and that resulting from controlled modification of the IOP was assessed, revealing high correlation (R2=0.98) and sensitivity and providing a high-precision measurement (5% estimated error) for the best experimental configuration. Future steps will be directed toward applying the proposed measurement principle in clinical trials for monitoring IOP with human subjects.

The effect of intraocular gas and fluid volumes on intraocular pressure.

PubMed

Simone, J N; Whitacre, M M

1990-02-01

Large increases in the intraocular pressure (IOP) of postoperative gas-containing eyes may require the removal of gas or fluid to reduce the IOP to the normal range. Application of the ideal gas law to Friedenwald's equation provides a mathematical model of the relationship between IOP, intraocular gas and fluid volumes, and the coefficient of scleral rigidity. This mathematic model shows that removal of a given volume of gas or fluid produces an identical decrease in IOP and that the more gas an eye contains, the greater the volume reduction necessary to reduce the pressure. Application of the model shows that the effective coefficient of scleral rigidity is low (mean K, 0.0021) in eyes with elevated IOP that have undergone vitrectomy and retinal cryopexy and very low (mean K, 0.0013) in eyes with elevated IOP that have undergone placement of a scleral buckle and band. By using the appropriate mean coefficient of rigidity, the volume of material to be aspirated to produce a given decrease in IOP can be predicted with clinically useful accuracy.

Toward Millions of File System IOPS on Low-Cost, Commodity Hardware.

PubMed

Zheng, Da; Burns, Randal; Szalay, Alexander S

2013-01-01

We describe a storage system that removes I/O bottlenecks to achieve more than one million IOPS based on a user-space file abstraction for arrays of commodity SSDs. The file abstraction refactors I/O scheduling and placement for extreme parallelism and non-uniform memory and I/O. The system includes a set-associative, parallel page cache in the user space. We redesign page caching to eliminate CPU overhead and lock-contention in non-uniform memory architecture machines. We evaluate our design on a 32 core NUMA machine with four, eight-core processors. Experiments show that our design delivers 1.23 million 512-byte read IOPS. The page cache realizes the scalable IOPS of Linux asynchronous I/O (AIO) and increases user-perceived I/O performance linearly with cache hit rates. The parallel, set-associative cache matches the cache hit rates of the global Linux page cache under real workloads.

Improving Coastal Ocean Color Validation Capabilities through Application of Inherent Optical Properties (IOPs)

NASA Technical Reports Server (NTRS)

Mannino, Antonio

2008-01-01

Understanding how the different components of seawater alter the path of incident sunlight through scattering and absorption is essential to using remotely sensed ocean color observations effectively. This is particularly apropos in coastal waters where the different optically significant components (phytoplankton, detrital material, inorganic minerals, etc.) vary widely in concentration, often independently from one another. Inherent Optical Properties (IOPs) form the link between these biogeochemical constituents and the Apparent Optical Properties (AOPs). understanding this interrelationship is at the heart of successfully carrying out inversions of satellite-measured radiance to biogeochemical properties. While sufficient covariation of seawater constituents in case I waters typically allows empirical algorithms connecting AOPs and biogeochemical parameters to behave well, these empirical algorithms normally do not hold for case I1 regimes (Carder et al. 2003). Validation in the context of ocean color remote sensing refers to in-situ measurements used to verify or characterize algorithm products or any assumption used as input to an algorithm. In this project, validation capabilities are considered those measurement capabilities, techniques, methods, models, etc. that allow effective validation. Enhancing current validation capabilities by incorporating state-of-the-art IOP measurements and optical models is the purpose of this work. Involved in this pursuit is improving core IOP measurement capabilities (spectral, angular, spatio-temporal resolutions), improving our understanding of the behavior of analytical AOP-IOP approximations in complex coastal waters, and improving the spatial and temporal resolution of biogeochemical data for validation by applying biogeochemical-IOP inversion models so that these parameters can be computed from real-time IOP sensors with high sampling rates. Research cruises supported by this project provides for collection and

Intraocular pressure, blood pressure, and retinal blood flow autoregulation: a mathematical model to clarify their relationship and clinical relevance.

PubMed

Guidoboni, Giovanna; Harris, Alon; Cassani, Simone; Arciero, Julia; Siesky, Brent; Amireskandari, Annahita; Tobe, Leslie; Egan, Patrick; Januleviciene, Ingrida; Park, Joshua

2014-05-29

This study investigates the relationship between intraocular pressure (IOP) and retinal hemodynamics and predicts how arterial blood pressure (BP) and blood flow autoregulation (AR) influence this relationship. A mathematical model is developed to simulate blood flow in the central retinal vessels and retinal microvasculature as current flowing through a network of resistances and capacitances. Variable resistances describe active and passive diameter changes due to AR and IOP. The model is validated by using clinically measured values of retinal blood flow and velocity. The model simulations for six theoretical patients with high, normal, and low BP (HBP-, NBP-, LBP-) and functional or absent AR (-wAR, -woAR) are compared with clinical data. The model predicts that NBPwAR and HBPwAR patients can regulate retinal blood flow (RBF) as IOP varies between 15 and 23 mm Hg and between 23 and 29 mm Hg, respectively, whereas LBPwAR patients do not adequately regulate blood flow if IOP is 15 mm Hg or higher. Hemodynamic alterations would be noticeable only if IOP changes occur outside of the regulating range, which, most importantly, depend on BP. The model predictions are consistent with clinical data for IOP reduction via surgery and medications and for cases of induced IOP elevation. The theoretical model results suggest that the ability of IOP to induce noticeable changes in retinal hemodynamics depends on the levels of BP and AR of the individual. These predictions might help to explain the inconsistencies found in the clinical literature concerning the relationship between IOP and retinal hemodynamics. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Choroidal hemodynamic changes during isometric exercise in patients with inactive central serous chorioretinopathy.

PubMed

Tittl, Michael; Maar, Noemi; Polska, Elzbieta; Weigert, Günther; Stur, Michael; Schmetterer, Leopold

2005-12-01

Imaging studies suggest that the choroidal vasculature may be altered in central serous chorioretinopathy. Little is known, however, about the regulation of ocular blood flow in patients with central serous chorioretinopathy (CSC). The hypothesis for the present study was that choroidal blood flow changes during an increase in ocular perfusion pressure induced by isometric exercise may be altered in CSC. An observer-masked, two-cohort study was performed in 14 nonsmoking patients with chronic-relapsing but inactive CSC and in 14 healthy nonsmoking volunteers. Both groups were matched for age and sex. Subfoveal choroidal blood flow (CBF) was assessed with laser Doppler flowmetry, and ocular perfusion pressure (OPP) was calculated from mean arterial pressure (MAP) and intraocular pressure (IOP). Changes of CBF during isometric exercise over a period of 6 minutes were measured. Whereas the increase of MAP, the pulse rate, and the OPP were comparable between the two study groups, subfoveal CBF increased significantly more in the group of patients with CSC (P < 0.001). IOP remained unchanged in both groups during isometric exercise. At an 85% increase in OPP, subfoveal CBF was approximately twice as high in the patients with CSC compared with the healthy control group. The data indicate an abnormal subfoveal CBF regulation in patients with relapsing CSC compared with age-matched, nonsmoking, healthy volunteers during isometric exercise.

Preservative-free treatment in glaucoma: who, when, and why.

PubMed

Stalmans, Ingeborg; Sunaric Mégevand, Gordana; Cordeiro, M Francesca; Hommer, Anton; Rossetti, Luca; Goñi, Francisco; Heijl, Anders; Bron, Alain

2013-01-01

To review and summarize the available literature on the effect of preservatives on the eye, to provide practical guidance for the clinical assessment of the ocular surface in glaucoma patients, and to define patient populations that might benefit from preservative-free topical intraocular pressure (IOP)-lowering agents. This manuscript is based on a combination of a literature review on preservatives and the eye and expert opinion from glaucoma specialists with an interest in ocular surface disease. There is an increasingly recognized association between eyedrop preservatives and ocular surface disease. Preservative-free therapy is now available for a wide range of active compounds, although there are still some misconceptions regarding their appropriate use. For patients treated topically for glaucoma or ocular hypertension, a rough estimate could be that 20% may need treatment with topical IOP-reducing agents that are free from preservatives. This review provides an up-to-date account of the literature regarding preservatives and the eye, as well as suggestions and recommendations on to when to use preservative-free antiglaucoma treatment.

Relationship between intra-abdominal pressure and trunk EMG.

PubMed

McGill, S M; Sharratt, M T

1990-05-01

Intra-abdominal pressure (IAP) has been proposed as an important mechanism in manual lifting and breathing mechanics. Direct (invasive) measures of IAP have required the swallowing of a radio transducer or insertion of a pressure sensor into the rectum or down the oesophagus to the stomach. The purpose of this study was to investigate the relationship between a non-invasive method (EMG) and IAP. Several tasks involving abdominal muscle activation were performed to assess whether or not IAP played a common role in these tasks. IAP and EMG from rectus abdominis, the abdominal obliques, intercostals and erector spinae were measured. Peak IAP reached 340 mmHg (valsalva) for one subject but most values were less than 100 mmHg for tasks other than valsalva. The IAP and EMG data provide some insight into the role of IAP during the performance of specific tasks. Peak IAP within 60 ms of the onset of vigorous abdominal activation indicated the importance of a very rapid pressure response to abdominal muscle activation. The correlations between various muscle EMG time histories and IAP exceeded 0·80 for only two activities (i.e. r(2) = 0·82 between the intercostals and IAP during valsalva manoeuvres). These data suggest that no unifying hypothesis exists to explain the role of IAP for a wide variety of movement tasks; rather, the role of IAP is task specific. Copyright © 1990. Published by Elsevier Ltd.

Intra-pelvic pressure changes after pelvic fracture: A cadaveric study quantifying the effect of a pelvic binder and limb bandaging over a bolster.

PubMed

Morris, Rhys; Loftus, Andrew; Friedmann, Yasmin; Parker, Paul; Pallister, Ian

2017-04-01

Unstable pelvic fractures can be life-threatening due to catastrophic haemorrhage. Non-invasive methods of reducing and stabilising these injuries include pelvic binder application and also lower limb bandaging over a knee-flexion bolster. Both of these methods help close the pelvic ring and should tamponade bleeding. This study aimed to quantify the intra-pelvic pressure changes that occurred with 3 different manoeuvres: lower limb bandaging over a bolster; a Trauma Pelvic Orthotic Device (T-POD) pelvic binder, and a combination of both. Following a pilot study with 2 soft embalmed cadavers, a formal study with 6 unembalmed cadavers was performed. For each specimen an unstable pelvic injury was created (OA/OTA 61-C1) by dividing the pelvic ring anteriorly and posteriorly. A 3-4cm manometric water-filled balloon was placed in the retropubic space and connected to a 50ml syringe and water manometer via a 3-way tap. A baseline pressure of 8cmH 2 O (equating to the average central venous pressure) was used for each cadaver. Steady intra-pelvic pressures (more reliably reflecting the pressures achieved following an intervention) were used in the subsequent statistical analysis, using R statistical language and Rstudio. Paired t-test or Wilcoxon's rank sum test were used (depending on the normality of the dataset) to determine the impact of each intervention on the intra-pelvic pressure. The mean steady intra-pelvic pressures were significantly greater than the baseline pressure for each intervention. The binder and limb bandaging over a bolster alone increased the mean steady pelvic pressures significantly to 24 (SE=5) (p<0.036) and 15.5 (SE=2) (p<0.02)cmH 2 O respectively. Combining these interventions further increased the mean steady pressure to 31 (SE=7)cmH 2 O. However, this was not significantly greater than pressures for each of the individual interventions. Both lower limb bandaging over a bolster and pelvic binder application significantly increased intra

Effects of Topical Latanoprost on Intraocular Pressure and Myopia Progression in Young Guinea Pigs

PubMed Central

El-Nimri, Nevin W.; Wildsoet, Christine F.

2018-01-01

Purpose To determine whether latanoprost, a prostaglandin analog proven to be very effective in reducing intraocular pressure (IOP) in humans, can also slow myopia progression in the guinea pig form deprivation (FD) model. Methods Two-week-old pigmented guinea pigs underwent monocular FD and daily topical latanoprost (0.005%, n = 10) or artificial tears (control, n = 10) starting 1 week after the initiation of FD, with all treatments continuing for a further 9 weeks. Tonometry, retinoscopy, and high-frequency A-scan ultrasonography were used to monitor IOP, refractive error, and ocular axial dimensions, respectively. Results Latanoprost significantly reduced IOP and slowed myopia progression. Mean interocular IOP differences (±SEM) recorded at baseline and week 10 were −0.30 ± 0.51 and 1.80 ± 1.16 mm Hg (P = 0.525) for the control group and 0.07 ± 0.35 and −5.17 ± 0.96 mm Hg (P < 0.001) for the latanoprost group. Equivalent interocular differences for optical axial length at baseline and week 10 were 0.00 ± 0.015 and 0.29 ± 0.04 mm (P < 0.001; control) and 0.02 ± 0.02 and 0.06 ± 0.02 mm (P = 0.202; latanoprost), and for refractive error were +0.025 ± 0.36 and −8.2 ± 0.71 diopter (D) (P < 0.001; control), and −0.15 ± 0.35 and −2.25 ± 0.54 D (P = 0.03; latanoprost). Conclusions In the FD guinea pig model, latanoprost significantly reduces the development of myopia. Although further investigations into underlying mechanisms are needed, the results open the exciting possibility of a new line of myopia control therapy. PMID:29847673

Effects of intra-abdominal pressure increase on intestinal ischemia and bacterial translocation in experimental sepsis model.

PubMed

Kesici, Ugur; Kesici, Sevgi; Polat, Erdal; Agca, Birol; Turkmen, Ulku A; Ozcan, Deniz; Sari, Musa K

2011-08-01

To investigate the safety of laparoscopic intervention for diagnosis and treatment at 8 mm Hg pressure in one-hour period on acute peritonitis related intra-abdominal sepsis model. In this study, we included 32 female Wistar-Albino rats, weighing 250 +/- 20 g, and divided them into 4 groups. This study was conducted in Istanbul University Experimental Medical Research Institution (DETAE) laboratory from April to May 2009. Intra-abdominal sepsis was created with intraperitoneal (i.p.) one mL (109 CFU/mL) Escherichia coli (E. coli) injection, and pneumoperitoneum was formed with CO2 insufflation at 8 mm Hg pressure for one hour i.p. The rats were administered with: Group 1 - one mL i.p. isotonic saline; Group 2 - one mL i.p. isotonic saline + pneumoperitoneum; Group 3 - i.p E. coli; and Group 4 - i.p. E.coli + pneumoperitoneum. Data were analyzed using the Statistical Package for Social Sciences version 15 for Windows (SPSS Inc, Chicago, IL, USA). Fever and leukocyte values were considered high in Groups 3 and 4 compared with Groups 1 and 2 (p=0.001). The administered reproduction ratio of the E. coli strain was determined as 0% in Groups 1 and 2, and 100% in Groups 3 and 4. In this study, as pneumoperitoneum was formed for one hour at 8 mm Hg pressure, in case of intra-abdominal derived sepsis where emergency intervention is needed, we consider that laparoscopic approaches with low pressure may be used safely for diagnosis and treatment.

Ocular Hypotensive Response in Nonhuman Primates of (8R)-1-[(2S)-2-Aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol a Selective 5-HT2 Receptor Agonist.

PubMed

May, Jesse A; Sharif, Najam A; McLaughlin, Marsha A; Chen, Hwang-Hsing; Severns, Bryon S; Kelly, Curtis R; Holt, William F; Young, Richard; Glennon, Richard A; Hellberg, Mark R; Dean, Thomas R

2015-11-25

Recently, it has been reported that 5-HT2 receptor agonists effectively reduce intraocular pressure (IOP) in a nonhuman primate model of glaucoma. Although 1-[(2S)-2-aminopropyl]indazol-6-ol (AL-34662) was shown to have good efficacy in this nonhuman primate model of ocular hypertension as well as a desirable physicochemical and permeability profile, subsequently identified cardiovascular side effects in multiple species precluded further clinical evaluation of this compound. Herein, we report selected structural modifications that resulted in the identification of (8R)-1-[(2S)-2-aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol (13), which displayed an acceptable profile to support advancement for further preclinical evaluation as a candidate for proof-of-concept studies in humans.

Toward Millions of File System IOPS on Low-Cost, Commodity Hardware

PubMed Central

Zheng, Da; Burns, Randal; Szalay, Alexander S.

2013-01-01

We describe a storage system that removes I/O bottlenecks to achieve more than one million IOPS based on a user-space file abstraction for arrays of commodity SSDs. The file abstraction refactors I/O scheduling and placement for extreme parallelism and non-uniform memory and I/O. The system includes a set-associative, parallel page cache in the user space. We redesign page caching to eliminate CPU overhead and lock-contention in non-uniform memory architecture machines. We evaluate our design on a 32 core NUMA machine with four, eight-core processors. Experiments show that our design delivers 1.23 million 512-byte read IOPS. The page cache realizes the scalable IOPS of Linux asynchronous I/O (AIO) and increases user-perceived I/O performance linearly with cache hit rates. The parallel, set-associative cache matches the cache hit rates of the global Linux page cache under real workloads. PMID:24402052

A Phase III Randomized Clinical Trial of a 0.5% Timolol + 0.2% Brimonidine + 2.0% Dorzolamide Fixed Combination, Preservative-Free Ophthalmic Solution vs. 0.5% Timolol + 0.2% Brimonidine + 2.0% Dorzolamide Fixed Combination in Patients with Controlled Primary Open-Angle Glaucoma.

PubMed

Gómez-Aguayo, Francisco; Paczka, José A; Leñero-Córdova, Rubén; Jiménez-Román, Jesús; Davila-Villarreal, Jaime; Hartleben, Curt; Baiza-Durán, Leopoldo; Olvera-Montaño, Oscar; García-Velez, Francisco; Muñoz-Villegas, Patricia

2018-06-01

The aim of this prospective crossover study was to evaluate the non-inferiority of PRO-122 (a preservative-free fixed combination) compared with 0.5% timolol + 0.2% brimonidine + 2.0% dorzolamide fixed combination (KOF) by evaluating its efficacy, tolerability and safety in subjects with controlled primary open-angle glaucoma (POAG) previously treated with KOF for at least 2 months. In a prospective, crossover, randomized, double-masked multicenter study, patients previously treated with KOF were randomly assigned to receive either PRO-122 or KOF for 30 days. On day 31, the A sequence changed to KOF, while the B sequence received PRO-122. All patients remained in the protocol for 30 additional days for a total of 60 days. The main efficacy endpoint was maintaining the controlled intraocular pressure (IOP). The safety and tolerability of both products were assessed by the presence of adverse events (AEs), ocular findings, a questionnaire on ocular comfort and the VF-14 index. A total of 51 patients participated. After application of PRO-122 twice a day, its efficacy was demonstrated through maintenance of the controlled IOP in patients previously controlled with KOF. The crossover between PRO-122 and KOF and vice versa, after 30 days of use, did not affect IOP control. PRO-122 was shown not to be inferior to KOF in maintaining IOP at control levels. The safety of both drugs is similar, as neither presented drug-related AEs or differences regarding safety issues. The tolerability of the two medications-evaluated by ocular findings, the questionnaire on ocular comfort and the VF-14 index-was also determined to be similar. The controlled IOP in patients with controlled POAG treated with PRO-122 was maintained both in relation to the initial controlled IOP of the study and when compared with KOF in the B sequence. Finally, the treatment with PRO-122 demonstrated similar safety and tolerability to KOF. Laboratorios Sophia, S.A. de C.V. (Zapopan, Jalisco, M�

An RFID-based on-lens sensor system for long-term IOP monitoring.

PubMed

Hsu, Shun-Hsi; Chiou, Jin-Chern; Liao, Yu-Te; Yang, Tzu-Sen; Kuei, Cheng-Kai; Wu, Tsung-Wei; Huang, Yu-Chieh

2015-01-01

In this paper, an RFID-based on-lens sensor system is proposed for noninvasive long-term intraocular pressure monitoring. The proposed sensor IC, fabricated in a 0.18um CMOS process, consists of capacitive sensor readout circuitry, RFID communication circuits, and digital processing units. The sensor IC is integrated with electroplating capacitive sensors and a receiving antenna on the contact lens. The sensor IC can be wirelessly powered, communicate with RFID compatible equipment, and perform IOP measurement using on-lens capacitive sensor continuously from a 2cm distance while the incident power from an RFID reader is 20 dBm. The proposed system is compatible to Gen2 RFID protocol, extending the flexibility and reducing the self-developed firmware efforts.

Patterns of intraocular pressure elevation after aqueous humor outflow obstruction in rats.

PubMed

Jia, L; Cepurna, W O; Johnson, E C; Morrison, J C

2000-05-01

To determine the diural intraocular pressure (IOP) response of Brown Norway rat eyes after sclerosis of the aqueous humor outflow pathways and its relationship to optic nerve damage. Hypertonic saline was injected into a single episcleral vein in 17 animals and awake IOP measured in both the light and dark phases of the circadian cycle for 34 days. Mean IOP for light and dark phases during the experimental period were compared with the respective pressures of the uninjected fellow eyes. Optic nerve cross sections from each nerve were graded for injury by five independent masked observers. For fellow eyes, mean light- and dark-phase IOP was 21 +/- 1 and 31 +/- 1 mm Hg, respectively. For four experimental eyes, mean IOPs for both phases were not altered. Six eyes demonstrated significant mean IOP elevations only during the dark phase. Of these, five showed persistent, large circadian oscillations, and four had partial optic nerve lesions. The remaining seven eyes experienced significant IOP elevations during both phases, and all had extensive optic nerve damage. Episcleral vein injection of hypertonic saline is more likely to increase IOP during the dark phase than the light. This is consistent with aqueous outflow obstruction superimposed on a circadian rhythm of aqueous humor production. Because these periodic IOP elevations produced optic nerve lesions, both light- and dark-phase IOP determinations are necessary for accurate correlation of IOP history to optic nerve damage in animals housed in a light- dark environment.

Responses of intra-abdominal pressure and abdominal muscle activity during dynamic trunk loading in man.

PubMed

Cresswell, A G

1993-01-01

The purpose of this study was to determine and compare interactions between the abdominal musculature and intra-abdominal pressure (IAP) during controlled dynamic and static trunk muscle loading. Myoelectric activity was recorded in six subjects from the rectus abdominis, obliquus externus, obliquus internus, transversus abdominis and erector spinae muscles using surface and intra-muscular fine-wire electrodes. The IAP was recorded intra-gastrically. Trunk flexions and extensions were performed lying on one side on a swivel table. An adjustable brake provided different friction loading conditions, while adding weights to an unbraked swivel table afforded various levels of inertial loading. During trunk extensions at all friction loads, IAP was elevated (1.8-7.2 kPa) with concomitant activity in transversus abdominis and obliquus internus muscles--little or no activity was seen from rectus abdominis and obliquus externus muscles. For inertia loading during trunk extension, IAP levels were somewhat lower (1.8-5.6 kPa) and displayed a second peak when abdominal muscle activity occurred in the course of decelerating the movement. For single trunk flexions with friction loading, IAP was higher than that seen in extension conditions and increased with added resistance. For inertial loading during trunk flexion, IAP showed two peaks, the larger first peak matched peak forward acceleration and general abdominal muscle activation, while the second corresponded to peak deceleration and was accompanied by activity in transversus abdominis and erector spinae muscles. It was apparent that different loading strategies produced markedly different patterns of response in both trunk musculature and intra-abdominal pressure.

Neuroprotective Effects of Transcription Factor Brn3b in an Ocular Hypertension Rat Model of Glaucoma

PubMed Central

Stankowska, Dorota L.; Minton, Alena Z.; Rutledge, Margaret A.; Mueller, Brett H.; Phatak, Nitasha R.; He, Shaoqing; Ma, Hai-Ying; Forster, Michael J.; Yorio, Thomas; Krishnamoorthy, Raghu R.

2015-01-01

Purpose. Glaucoma is an optic neuropathy commonly associated with elevated intraocular pressure (IOP), leading to optic nerve head (ONH) cupping, axon loss, and apoptosis of retinal ganglion cells (RGCs), which could ultimately result in blindness. Brn3b is a class-4 POU domain transcription factor that plays a key role in RGC development, axon outgrowth, and pathfinding. Previous studies suggest that a decrease in Brn3b levels occurs in animal models of glaucoma. The goal of this study was to determine if adeno-associated virus (AAV)-directed overexpression of the Brn3b protein could have neuroprotective effects following elevated IOP-mediated neurodegeneration. Methods. Intraocular pressure was elevated in one eye of Brown Norway rats (Rattus norvegicus), following which the IOP-elevated eyes were intravitreally injected with AAV constructs encoding either the GFP (rAAV-CMV-GFP and rAAV-hsyn-GFP) or Brn3b (rAAV-CMV-Brn3b and rAAV-hsyn-Brn3b). Retina sections through the ONH were stained for synaptic plasticity markers and neuroprotection was assessed by RGC counts and visual acuity tests. Results. Adeno-associated virus–mediated expression of the Brn3b protein in IOP-elevated rat eyes promoted an upregulation of growth associated protein-43 (GAP-43), actin binding LIM protein (abLIM) and acetylated α-tubulin (ac-Tuba) both posterior to the ONH and in RGCs. The RGC survival as well as axon integrity score were significantly improved in IOP-elevated rAAV-hsyn-Brn3b–injected rats compared with those of the IOP-elevated rAAV-hsyn-GFP– injected rats. Additionally, intravitreal rAAV-hsyn-Brn3b administration significantly restored the visual optomotor response in IOP-elevated rat eyes. Conclusions. Adeno-associated virus–mediated Brn3b protein expression may be a suitable approach for promoting neuroprotection in animal models of glaucoma. PMID:25587060

Diagnostic accuracy of intraocular pressure measurement for the detection of raised intracranial pressure: meta-analysis: a systematic review.

PubMed

Yavin, Daniel; Luu, Judy; James, Matthew T; Roberts, Derek J; Sutherland, Garnette R; Jette, Nathalie; Wiebe, Samuel

2014-09-01

Because clinical examination and imaging may be unreliable indicators of intracranial hypertension, intraocular pressure (IOP) measurement has been proposed as a noninvasive method of diagnosis. The authors conducted a systematic review and meta-analysis to determine the correlation between IOP and intracranial pressure (ICP) and the diagnostic accuracy of IOP measurement for detection of intracranial hypertension. The authors searched bibliographic databases (Ovid MEDLINE, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials) from 1950 to March 2013, references of included studies, and conference abstracts for studies comparing IOP and invasive ICP measurement. Two independent reviewers screened abstracts, reviewed full-text articles, and extracted data. Correlation coefficients, sensitivity, specificity, and positive and negative likelihood ratios were calculated using DerSimonian and Laird methods and bivariate random effects models. The I(2) statistic was used as a measure of heterogeneity. Among 355 identified citations, 12 studies that enrolled 546 patients were included in the meta-analysis. The pooled correlation coefficient between IOP and ICP was 0.44 (95% CI 0.26-0.63, I(2) = 97.7%, p < 0.001). The summary sensitivity and specificity for IOP for diagnosing intracranial hypertension were 81% (95% CI 26%-98%, I(2) = 95.2%, p < 0.01) and 95% (95% CI 43%-100%, I(2) = 97.7%, p < 0.01), respectively. The summary positive and negative likelihood ratios were 14.8 (95% CI 0.5-417.7) and 0.2 (95% CI 0.02-1.7), respectively. When ICP and IOP measurements were taken within 1 hour of another, correlation between the measures improved. Although a modest aggregate correlation was found between IOP and ICP, the pooled diagnostic accuracy suggests that IOP measurement may be of clinical utility in the detection of intracranial hypertension. Given the significant heterogeneity between included studies, further investigation is required prior to the adoption