Epidemiology of eye disease in the elderly

Vision impairment and access to eye care in an integrated network of eye care system in Southern and Eastern India

PURPOSE

The World Report on Vision highlights that health information systems (HIS) should collect information on the determinants of eye conditions and vision impairment (VI) as a step toward integrated people-centered eye care (IPEC). Thus, this retrospective study aims to elucidate VI trends across age and gender of the patients who visited our centres in southern and eastern India.

METHODS

Electronic medical records of all new patients who visited the network were included. VI was defined as visual acuity less than 6/12; unilateral VI was based on the worse presenting eye (the other eye being normal), and bilateral VI was based on the better eye. "Total VI" includes both unilateral and bilateral VI.

RESULTS

The records of 7,31,307 patients from January to December 2019 were extracted. Males were 54%. The mean age was 40 years (SD: 19.16 years). The majority of patients (46.54%) visited a primary care centre. Centres in Andhra Pradesh saw the largest number of patients (46%). Approximately 65% of all patients presented had no VI in either eye. Total VI was 23.5% at the primary-centre level and approximately 45% at other levels, the highest being in Odisha. More females accessed care at primary and secondary centres (46.6%) than at higher levels of care (44%). Odisha had the lowest number of females accessing care (43.01%).

CONCLUSION

Non-visually impairing conditions form an important reason for patients visiting our eye care facilities. Strategies focusing on improving access to eye care for females should be planned at all levels, especially in Odisha.

Biomaterial Drug Delivery Systems for Prominent Ocular Diseases

Ocular diseases, such as age-related macular degeneration (AMD) and glaucoma, have had a profound impact on millions of patients. In the past couple of decades, these diseases have been treated using conventional techniques but have also presented certain challenges and limitations that affect patient experience and outcomes. To address this, biomaterials have been used for ocular drug delivery, and a wide range of systems have been developed. This review will discuss some of the major classes and examples of biomaterials used for the treatment of prominent ocular diseases, including ocular implants (biodegradable and non-biodegradable), nanocarriers (hydrogels, liposomes, nanomicelles, DNA-inspired nanoparticles, and dendrimers), microneedles, and drug-loaded contact lenses. We will also discuss the advantages of these biomaterials over conventional approaches with support from the results of clinical trials that demonstrate their efficacy.

2D Semiconductor Based Flexible Photoresponsive Ring Oscillators for Artificial Vision Pixels

Artificial retina implantation provides an effective and feasible attempt for vision recovery in addition to retinal transplantation. The most advanced artificial retinas ever developed based on silicon technology are rigid and thus less compatible with the biosystem. Here we demonstrate flexible photoresponsive ring oscillators (PROs) based on the 2D semiconductor MoS2 for artificial retinas. Under natural light illuminations, arrayed PROs on flexible substrates serving as vision pixels can efficiently output light-intensity-dependent electrical pulses that are processable and transmittable in the human visual nerve system. Such PROs can work under low supply voltages below 1 V with a record-low power consumption, e.g. only 12.4 nW at a light intensity of 10 mW/cm2, decreased by ∼500 times compared with that of the state-of-the-art silicon devices. Such flexible artificial retinas with a simple device structure, high light-to-signal conversion efficiency, ultralow power consumption, and high tunability provide an alternative prosthesis for further clinical trials.

Retinal and choroidal changes in AMD: A systematic review and meta-analysis of spectral-domain optical coherence tomography studies

Optical coherence tomography is a noninvasive imaging technology using the optical reflectivity of tissues that is capable of detecting quantitative and qualitative biomarkers of age-related macular degeneration (AMD) that cannot be similarly recognized in conventional imaging. We systematically searched PubMed and Embase databases to identify relevant articles to this subject. A fixed-effect or random-effect model was applied for the meta-analysis based on the heterogeneity level. In addition, subgroup analyses, meta-regression, publication bias, and quality assessment were also performed. Twenty-five studies with 1,632 cases and 1,445 healthy controls in total were included. Our results revealed that, when compared to controls, AMD subjects showed a significantly lower thickness in the choroid at 500 µm temporal, 1,500 µm nasal, and temporal to the fovea, subfoveal choroid, average peripapillary retinal nerve fiber layer, and average macular ganglion cell complex (GCC); however, average and central choroidal thickness 500 µm nasal, 1,000 µm nasal and temporal to the fovea, central and parafoveal macular GCC, retinal nerve fiber layer, and inner plexiform layer, and central macular thickness did not change significantly. Various regional analyses showed several other significant differences. The findings of the current study confirm that some retinal layers are altered in AMD patients compared to healthy controls. Thus, future studies are required to derive more definitive conclusions.

Development of Moderate Intensity Focused Ultrasound (MIFU) for Ocular Drug Delivery

The purpose of this study is to develop a method for delivering antiinflammatory agents of high molecular weight (e.g., Avastin) into the posterior segment that does not require injections into the eye (i.e., intravitreal injections; IVT). Diseases affecting the posterior segment of the eye are currently treated with monthly to bimonthly intravitreal injections, which can predispose patients to severe albeit rare complications like endophthalmitis, retinal detachment, traumatic cataract, and/or increased intraocular. In this study, we show that one time moderate intensity focused ultrasound (MIFU) treatment can facilitate the penetration of large molecules across the scleral barrier, showing promising evidence that this is a viable method to deliver high molecular weight medications not invasively. To validate the efficacy of the drug delivery system, IVT injections of vascular endothelial growth factor (VEGF) were used to create an animal model of retinopathy. The creation of this model allowed us to test anti-VEGF medications and evaluate the efficacy of the treatment. In vivo testing showed that animals treated with our MIFU device improved on the retinal tortuosity and clinical dilation compared to the control group while evaluating fluorescein angiogram (FA) Images.

Incidence and Risk Factors of Epiretinal Membrane after Cataract Surgery

Purpose: To investigate the incidence and risk factors of epiretinal membrane (ERM) after cataract surgery.Methods: We reviewed the medical records of patients who underwent cataract surgery between January 2016 and December 2018. Eyes with ERM, as observed by optical coherence tomography performed 1-2 months after surgery, were excluded from the study. ERM was diagnosed by fundus photography. The incidence rate was determined 2-6, 6-12, and 12-24 months after surgery. The cumulative incidence rate of ERM was calculated by Kaplan-Meier analysis. Data were analyzed using logistic regression to determine the associations between ERM development and various factors.Results: The study included 218 eyes of 161 patients with a mean age of 66.6 ± 9.7 years at the time of surgery. ERM was observed in 3 of 218 eyes (1.4%) between 2 and 6 months, 15 of 176 eyes (8.3%) between 6 and 12 months, and 14 of 150 eyes (10.3%) between 12 and 24 months after surgery. The cumulative incidence rate of ERM was 11.7% over the 24-month period after surgery. In multivariate logistic regression analysis, older age (≥65 years; odds ratio [OR], 8.59, 95% confidence interval [CI], 1.43-51.49), fellow eye with ERM (OR, 3.63; 95% CI, 1.04-12.73), longer axial length (≥26 mm; OR, 8.02; 95% CI, 1.08-59.66), and complete posterior vitreous detachment development (OR, 7.48; 95% CI, 1.64-34.14) were significantly associated with ERM development.Conclusions: ERM is not rare after cataract surgery. Long-term retinal examination should be required after cataract surgery.

A mobile vision testing application based on dynamic distance determination from the human corneal limbus

Here we present a mobile application that accurately determines the distance between an optical sensor and the human corneal limbus for visual acuity assessment. The application uses digital image processing and randomized circle detection to locate the cornea. Then, a reference scaling measurement is employed to calculate distance from the sensor to a user. To determine accuracy and generalizability, testing was conducted both with 200 static images, 25 images each of males and females for four ethnic groups from a facial image database, and live image streams from a test subject. Average absolute corneal radius error over 10 trials for the static images was 6.36%, while average absolute distance error for the live image streams was less than 1%. Subsequently, distance measurements were used to scale letter sizes for a Snellen Chart-based visual acuity assessment. This system enables monitoring of chronic retinal diseases, as patients can quickly and accurately measure their visual acuity through the mobile eye exam suite.

Complete RPE and outer retinal atrophy in patients receiving anti-VEGF treatment for neovascular age-related macular degeneration

IMPORTANCE

Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness with several intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents available for its management such as aflibercept, bevacizumab, and ranibizumab. However, direct comparisons between these three agents among the same patient population are limited.

OBJECTIVE

To assess the rate and growth of complete retinal pigment epithelium and outer retinal atrophy (cRORA) in eyes with nAMD treated with aflibercept, bevacizumab, and/or ranibizumab.

METHOD

Retrospective cohort study of patients with treatment-naïve neovascular AMD seen at an academic hospital between October 2006 and February 2019. Study eyes were treated with intravitreal injections of aflibercept, bevacizumab, and/or ranibizumab and followed for two years.

MAIN OUTCOMES AND MEASURES

cRORA prevalence, location, size, and growth rate. Eyes were imaged with Cirrus spectral domain optical coherence tomography (SD-OCT). Presence and size of cRORA were calculated using the FDA-approved Advanced RPE Analysis software. Linear regression models were used to correlate cRORA progression with baseline demographic and ocular characteristics, anti-VEGF drug, and number of injections. Unpaired t-tests, ANOVA, and linear regression models were computed with SAS 9.4.

RESULTS

197 eyes from 158 patients (mean age 78.9, 62.9% women) received an average of 13 anti-VEGF injections over 24 months. 22% developed new cRORA. Mean cRORA area increased from 1.71 mm2 to 2.93 mm2. At 24 months, eyes with 11+ injections had significantly less cRORA area (11+ injections, 4.02 mm2; ≤ 10 injections, 2.46 mm2; p = 0.01) and growth rate (11+ injections, 0.41 mm2/year; ≤ 10 injections, 1.05 mm2/year; p = 0.02). Choice of anti-VEGF drug yielded no significant difference in cRORA progression.

CONCLUSIONS AND RELEVANCE

Treating nAMD with aflibercept, bevacizumab or ranibizumab demonstrated comparable cRORA development at 24 months. Number of injections inversely correlated with cRORA area and growth. These results warrant further investigation in the pathophysiology of cRORA in anti-VEGF treated eyes.

Ocular blood flow as a clinical observation: Value, limitations and data analysis

Alterations in ocular blood flow have been identified as important risk factors for the onset and progression of numerous diseases of the eye. In particular, several population-based and longitudinal-based studies have provided compelling evidence of hemodynamic biomarkers as independent risk factors for ocular disease throughout several different geographic regions. Despite this evidence, the relative contribution of blood flow to ocular physiology and pathology in synergy with other risk factors and comorbidities (e.g., age, gender, race, diabetes and hypertension) remains uncertain. There is currently no gold standard for assessing all relevant vascular beds in the eye, and the heterogeneous vascular biomarkers derived from multiple ocular imaging technologies are non-interchangeable and difficult to interpret as a whole. As a result of these disease complexities and imaging limitations, standard statistical methods often yield inconsistent results across studies and are unable to quantify or explain a patient's overall risk for ocular disease. Combining mathematical modeling with artificial intelligence holds great promise for advancing data analysis in ophthalmology and enabling individualized risk assessment from diverse, multi-input clinical and demographic biomarkers. Mechanism-driven mathematical modeling makes virtual laboratories available to investigate pathogenic mechanisms, advance diagnostic ability and improve disease management. Artificial intelligence provides a novel method for utilizing a vast amount of data from a wide range of patient types to diagnose and monitor ocular disease. This article reviews the state of the art and major unanswered questions related to ocular vascular anatomy and physiology, ocular imaging techniques, clinical findings in glaucoma and other eye diseases, and mechanistic modeling predictions, while laying a path for integrating clinical observations with mathematical models and artificial intelligence. Viable alternatives for integrated data analysis are proposed that aim to overcome the limitations of standard statistical approaches and enable individually tailored precision medicine in ophthalmology.

Vision Loss Among Delaware Nursing Home Residents

Objectives: To determine the prevalence of vision loss among Delaware nursing home residents for further data collection to expand the existing evidence about the vision loss among nursing home residents on a national level. Methods: This cross-sectional study involved the statistical analysis of comprehensive eye examination records of 1,856 nursing residents residing in 20 Delaware nursing homes from 2005 to 2011. Descriptive statistical analyses were conducted to identify age-specific prevalence rates of vision loss (moderate-to-severe vision impairment and blindness). Results: The mean age of nursing home residents was 82.54 years (range: 65-111 years), and 61.70% were over the age of 80 years. The majority of nursing home residents were female (64.10%) and White (76.30%). The overall prevalence rates of moderate-to-severe vision impairment and blindness were 47.40% and 16.20%, respectively. Discussion: The high prevalence of vision loss among Delaware Nursing home residents indicates a demand for further data collection for expanding the existing evidence about the vision loss among nursing home residents on a national level.

Tobacco smoking is an independent factor associated with retinal damage in systemic lupus erythematosus: a cross-sectional and retrospective study

To analyze the influence of tobacco smoking on systemic lupus erythematosus (SLE) clinical features and damage. Cross-sectional and retrospective, case-control study comparing SLE patients with and without tobacco exposure. Cumulative clinical data and comorbidities were collected, and severity (Katz index) and damage (SLICC/ACR damage index) (SDI) indices were calculated. Pack-years (PY) was used to estimate lifetime tobacco exposure. A logistic regression was carried out to explore the impact of tobacco use on retinal damage. 216 patients were included. The mean age was 49 years (± 12.7), 93% were females, and median disease duration was 17 years [interquartile range (IQR):9-25]. Fifty-three percent of patients were smokers at some point. The median PY was 13 (IQR: 6-20.5). Only 54.8% of active smokers recalled having been informed of the negative effects of smoking, versus 83.3% of never smokers (< 0.001). In a bivariant analysis, an association between tobacco use at any time and discoid lupus [OR: 3.5(95%CI 1.5-8.9); p = 0.002] photosensitivity [OR: 2.06(95%CI 1.16-3.7); p = 0.01] and peripheral arteriopathy (p = 0.007) was found. Considering SDI item by item, a significant association with retinal damage, adjusted for age [OR: 1.03(95%CI 1-1.07); p = 0.04], was found. Using PYs, an association was found with discoid lupus (p = 0.01), photosensitivity (p = 0.03) and peripheral arteriopathy (p = 0.01), global SDI > 0 (p = 0.002) and retinal damage (p = 0.02). In a multivariate analysis exploring factors associated with retinal damage, any previous smoking history and SDI remained associated with retinal damage. Tobacco smoking is associated with cutaneous manifestations and damage and is an independent predictor of retinal damage in SLE patients.

Anti-vascular endothelial growth factor for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to AMD accounts for most cases of AMD-related severe vision loss. Intravitreous injection of anti-vascular endothelial growth factor (anti-VEGF) agents aims to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, to improve vision.

OBJECTIVES

• To investigate ocular and systemic effects of, and quality of life associated with, intravitreous injection of three anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) versus no anti-VEGF treatment for patients with neovascular AMD• To compare the relative effects of one of these anti-VEGF agents versus another when administered in comparable dosages and regimens SEARCH METHODS: To identify eligible studies for this review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (searched January 31, 2018); MEDLINE Ovid (1946 to January 31, 2018); Embase Ovid (1947 to January 31, 2018); the Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 31, 2018); the International Standard Randomized Controlled Trials Number (ISRCTN) Registry (www.isrctn.com/editAdvancedSearch - searched January 31, 2018); ClinicalTrials.gov (www.clinicaltrials.gov - searched November 28, 2018); and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en - searched January 31, 2018). We did not impose any date or language restrictions in electronic searches for trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or versus a control treatment (e.g. sham treatment, photodynamic therapy), in which participants were followed for at least one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We compared outcomes using risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 16 RCTs that had enrolled a total of 6347 participants with neovascular AMD (the number of participants per trial ranged from 23 to 1208) and identified one potentially relevant ongoing trial. Six trials compared anti-VEGF treatment (pegaptanib, ranibizumab, or bevacizumab) versus control, and 10 trials compared bevacizumab versus ranibizumab. Pharmaceutical companies conducted or sponsored four trials but funded none of the studies that evaluated bevacizumab. Researchers conducted these trials at various centers across five continents (North and South America, Europe, Asia, and Australia). The overall certainty of the evidence was moderate to high, and most trials had an overall low risk of bias. All but one trial had been registered prospectively.When compared with those who received control treatment, more participants who received intravitreous injection of any of the three anti-VEGF agents had gained 15 letters or more of visual acuity (risk ratio [RR] 4.19, 95% confidence interval [CI] 2.32 to 7.55; moderate-certainty evidence), had lost fewer than 15 letters of visual acuity (RR 1.40, 95% CI 1.27 to 1.55; high-certainty evidence), and showed mean improvement in visual acuity (mean difference 6.7 letters, 95% CI 4.4 to 9.0 in one pegaptanib trial; mean difference 17.8 letters, 95% CI 16.0 to 19.7 in three ranibizumab trials; moderate-certainty evidence) after one year of follow-up. Participants treated with anti-VEGF agents showed improvement in morphologic outcomes (e.g. size of CNV, central retinal thickness) compared with participants not treated with anti-VEGF agents (moderate-certainty evidence). No trial directly compared pegaptanib versus another anti-VEGF agent and followed participants for one year; however, when compared with control treatments, ranibizumab and bevacizumab each yielded larger improvements in visual acuity outcomes than pegaptanib.Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same RCTs compared the same regimens with respect to gain of 15 or more letters of visual acuity (RR 0.95, 95% CI 0.81 to 1.12; high-certainty evidence) and loss of fewer than 15 letters of visual acuity (RR 1.00, 95% CI 0.98 to 1.02; high-certainty evidence); results showed similar mean improvement in visual acuity (mean difference [MD] -0.5 letters, 95% CI -1.5 to 0.5; high-certainty evidence) after one year of follow-up, despite the substantially lower cost of bevacizumab compared with ranibizumab. Reduction in central retinal thickness was less among bevacizumab-treated participants than among ranibizumab-treated participants after one year (MD -11.6 μm, 95% CI -21.6 to -1.7; high-certainty evidence); however, this difference is within the range of measurement error, and we did not interpret it to be clinically meaningful.Ocular inflammation and increased intraocular pressure (IOP) after intravitreal injection were the most frequently reported serious ocular adverse events. Researchers reported endophthalmitis in less than 1% of anti-VEGF-treated participants and in no cases among control groups. The occurrence of serious systemic adverse events was comparable across anti-VEGF-treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to show a meaningful difference between groups (evidence of low- to moderate-certainty). Investigators rarely measured and reported data on visual function, quality of life, or economic outcomes.

AUTHORS' CONCLUSIONS

Results of this review show the effectiveness of anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; studies show that ranibizumab and bevacizumab improved visual acuity in some eyes that received these agents and were equally effective. Available information on the adverse effects of each medication does not suggest a higher incidence of potentially vision-threatening complications with intravitreous injection of anti-VEGF agents compared with control interventions; however, clinical trial sample sizes were not sufficient to estimate differences in rare safety outcomes. Future Cochrane Reviews should incorporate research evaluating variable dosing regimens of anti-VEGF agents, effects of long-term use, use of combination therapies (e.g. anti-VEGF treatment plus photodynamic therapy), and other methods of delivering these agents.

Preventing Progression in Nonexudative Age-Related Macular Degeneration With Subthreshold Laser Therapy: A Systematic Review

BACKGROUND AND OBJECTIVE

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly in developed countries. Subthreshold retinal laser therapy is a new technique that targets drusen - a marker of nonexudative AMD - without causing incidental retinal damage associated with conventional laser photocoagulation. This review summarizes published literature on subthreshold retinal laser therapy as prophylactic treatment of nonexudative AMD.

PATIENTS AND METHODS

A literature search of the PubMed, Medline, and Embase databases was conducted from January 1997 to April 2018. Studies were analyzed based upon study design, laser parameters, drusen reduction, changes in visual acuity (VA), and the development of choroidal neovascularization (CNV) and/or geographic atrophy (GA).

RESULTS

Twelve studies involving 2,481 eyes treated with subthreshold retinal laser therapy were included in this review. Treatment led to increased drusen reduction, and studies with significant VA improvement were associated with significant drusen reduction. There was no significant change in the risk of developing CNV or GA.

CONCLUSIONS

Subthreshold retinal laser therapy is effective for reducing drusen and potentially improving vision in patients with nonexudative AMD. This therapy does not show benefits in reducing development of CNV or GA. Thus, its long-term efficacy to prevent progression to advanced AMD cannot yet be recommended. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e61-e70.].

The prevalence of Eye Disease in Elderly Bengalis in Tower Hamlets

The prevalence of eye disease and uncorrected refractive errors in a group of 167 elderly members of the Bangladeshi community which resides in the London Borough of Tower Hamlets was studied. Of the subjects screened 24.6% were found to have a significant and potentially treatable cause of visual loss and a further 32.3% were visually handicapped through the presence of uncorrected refractive errors. A high prevalence (53.3%) of cataract was found in the elderly Bengalis. The high prevalence of eye disease in this ethnic minority group, has important implications for health service planning.

Effects of Aflibercept for Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis of Observational Comparative Studies

Purposes

To compare the effects of aflibercept and other anti-vascular endothelial growth factor (anti-VEGF) medications on both functional and anatomical outcomes for treatment-naïve neovascular age-related macular degeneration (nAMD) in the real world.

Methods

A systematic review and meta-analysis of observational comparative studies.

Results

A total of 18 studies remained after literature selection and quality assessment of 1697 studies. The most common aflibercept treatment regimen was three monthly injections followed by pro re nata (PRN). Aflibercept and ranibizumab had similar effects in 2-year treatment. At 3, 6, 12, and 24 months, the differences in the logarithm of minimum angle of resolution (logMAR) decrease in aflibercept and ranibizumab groups were 0.00 (95% confidence interval [CI]: −0.03 to 0.02); 0.01 (95% CI: −0.02 to 0.05); −0.03 (95% CI: −0.07 to 0.01); and –0.06 (95% CI: −0.30 to 0.17), respectively; the differences in decrease of central retinal thickness (CRT) were 3.25 μm (95% CI: −15.03 to 21.53); 7.89 μm (95% CI: −31.91 to 47.69); 2.89 μm (95% CI: −18.33 to 24.11); and −2.42 μm (95% CI: −77.87 to 73.03), respectively. However, aflibercept was significantly more effective in patients with initial reduced visual acuity (logMAR >0.6 or <55 letters; P = 0.001). In the first year, treatment frequency was not significantly different for aflibercept and ranibizumab, but aflibercept required fewer injections than ranibizumab with PRN regimen (mean −0.90; 95% CI: −1.80 to 0.00).

Conclusions

Aflibercept has comparable effects with ranibizumab for treatment-naïve nAMD in the real world, and may be more effective for patients with initial lower visual acuity.

The Relationship Between Reticular Macular Disease and Choroidal Thickness

PURPOSE

Subretinal drusenoid deposits (SDD) are the main structural lesion of reticular macular disease (RMD), a phenotype of age-related macular degeneration (AMD). We aim to demonstrate spatiotemporal relationships between SDD and choroidal thickness (CTh) alterations in RMD+ and RMD- eyes.

METHODS

Thirty-three eyes (26 subjects) with early AMD/no SDD (RMD-) and 18 eyes (16 subjects) with early AMD/SDD (RMD+) underwent enhanced depth imaging spectral domain optical coherence tomography (SD-OCT) for CTh measurements at 11 points per scan, in 5 horizontal B scans, creating a grid of 55 points/eye. The 55 points were treated as a cluster, controlling within-subject correlation. Marginal generalized estimating equation modeling was used to estimate the association between CTh and RMD status. All eyes were divided by their median age (≤82 and >82 years) for stratified analyses.

RESULTS

CTh was not significantly reduced in RMD+ eyes compared with RMD- eyes (mean difference [MD] -16.84 μm, P = 0.24). Among younger subjects, mean CTh was significantly reduced in RMD+ versus RMD- eyes (MD -53.72 μm, P = 0.01). Conversely, among older subjects, there was no significant difference in CTh between RMD+ and RMD-.

CONCLUSIONS

In RMD, the association of SDD and CTh alterations varies with age but not by macular region. Among younger subjects (<82 years old), CTh was significantly thinner in RMD+ versus RMD- eyes.

Anti-vascular endothelial growth factor for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to neovascular AMD accounts for most AMD-related severe vision loss. Anti-vascular endothelial growth factor (anti-VEGF) agents, injected intravitreally, aim to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, improve vision.

OBJECTIVES

To investigate: (1) the ocular and systemic effects of, and quality of life associated with, intravitreally injected anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) for the treatment of neovascular AMD compared with no anti-VEGF treatment; and (2) the relative effects of one anti-VEGF agent compared with another when administered in comparable dosages and regimens.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to March 2014), EMBASE (January 1980 to March 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 27 March 2014.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or a control treatment (e.g., sham treatment or photodynamic therapy). All trials followed participants for at least one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We analyzed outcomes as risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 12 RCTs including a total of 5496 participants with neovascular AMD (the number of participants per trial ranged from 28 to 1208). One trial compared pegaptanib, three trials ranibizumab, and two trials bevacizumab versus controls; six trials compared bevacizumab with ranibizumab. Four trials were conducted by pharmaceutical companies; none of the eight studies which evaluated bevacizumab were funded by pharmaceutical companies. The trials were conducted at various centers across five continents (North and South America, Europe, Asia and Australia). The overall quality of the evidence was very good, with most trials having an overall low risk of bias.When compared with control treatments, participants who received any of the three anti-VEGF agents were more likely to have gained 15 letters or more of visual acuity, lost fewer than 15 letters of visual acuity, and had vision 20/200 or better after one year of follow up. Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same regimens were compared in the same RCTs, despite the substantially lower cost for bevacizumab compared with ranibizumab. No trial directly compared pegaptanib with other anti-VEGF agents; however, when compared with controls, ranibizumab or bevacizumab yielded larger improvements in visual acuity outcomes than pegaptanib.Participants treated with anti-VEGFs showed improvements in morphologic outcomes (e.g., size of CNV or central retinal thickness) compared with participants not treated with anti-VEGF agents. There was less reduction in central retinal thickness among bevacizumab-treated participants than among ranibizumab-treated participants after one year (MD -13.97 μm; 95% confidence interval (CI) -26.52 to -1.41); however, this difference is within the range of measurement error and we did not interpret it as being clinically meaningful.Ocular inflammation and increased intraocular pressure after intravitreal injection were the most frequently reported serious ocular adverse events. Endophthalmitis was reported in fewer than 1% of anti-VEGF treated participants; no cases were reported in control groups. The occurrence of serious systemic adverse events was comparable across anti-VEGF-treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to detect a meaningful difference between groups. Data for visual function, quality of life, and economic outcomes were sparsely measured and reported.

AUTHORS' CONCLUSIONS

The results of this review indicate the effectiveness of anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; ranibizumab and bevacizumab were also shown to improve visual acuity. The information available on the adverse effects of each medication do not suggest a higher incidence of potentially vision-threatening complications with intravitreal injection compared with control interventions; however, clinical trial sample sizes may not have been sufficient to detect rare safety outcomes. Research evaluating variable dosing regimens with anti-VEGF agents, effects of long-term use, combination therapies (e.g., anti-VEGF treatment plus photodynamic therapy), and other methods of delivering the agents should be incorporated into future Cochrane reviews.

Risk factors associated with reticular pseudodrusen versus large soft drusen

PURPOSE

To investigate genetic, environmental, and systemic risk factors in prospectively identified subjects with the age-related macular degeneration (AMD) phenotypes of (1) reticular pseudodrusen without large soft drusen and (2) large soft drusen without reticular pseudodrusen.

DESIGN

Prospective case-case comparison.

METHODS

In a clinical practice setting, patients with AMD were sequentially screened using clinical examination and scanning laser ophthalmoscopy imaging to prospectively identify subjects (n = 73) with the phenotypes of (1) reticular pseudodrusen without large soft drusen (n = 30) or (2) large soft drusen without reticular pseudodrusen (n = 43). Subjects were genotyped for 2 alleles associated with AMD, age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH). A questionnaire was administered to collect history of smoking, hypertension, diabetes, and hyperlipidemia, as well as personal and family history of AMD.

RESULTS

The reticular pseudodrusen group was older (median age 87 vs 81 years, P = .04) and had more female subjects (83.3% vs 48.8%, P = .003), later ages of AMD onset (83 vs 70 years, P = .0005), and a greater frequency of hypertension (76.7% vs 55.8%, P = .08). No significant differences were found in the distribution of the ARMS2 risk allele (P = .4) between the reticular pseudodrusen (homozygous = 20.0%; heterozygous = 56.7%) and large soft drusen (homozygous = 19.0%; heterozygous = 42.9%) phenotypes, or in the distribution of the CHF risk allele (P = .7) between the reticular pseudodrusen (homozygous = 26.7%; heterozygous = 56.7%) and large soft drusen (homozygous = 21.4%; heterozygous = 66.7%) phenotypes.

CONCLUSIONS

The reticular pseudodrusen phenotype was associated with increased age, later age of AMD onset, and female sex.

The effect of modified eggs and an egg-yolk based beverage on serum lutein and zeaxanthin concentrations and macular pigment optical density: results from a randomized trial

Increasing evidence suggests a beneficial effect of lutein and zeaxanthin on the progression of age-related macular degeneration. The aim of this study was to investigate the effect of lutein or zeaxanthin enriched eggs or a lutein enriched egg-yolk based buttermilk beverage on serum lutein and zeaxanthin concentrations and macular pigment levels. Naturally enriched eggs were made by increasing the levels of the xanthophylls lutein and zeaxanthin in the feed given to laying hens. One hundred healthy volunteers were recruited and randomized into 5 groups for 90 days. Group one added one normal egg to their daily diet and group two received a lutein enriched egg-yolk based beverage. Group three added one lutein enriched egg and group four one zeaxanthin enriched egg to their diet. Group five was the control group and individuals in this group did not modify their daily diet. Serum lutein and zeaxanthin concentrations and macular pigment densities were obtained at baseline, day 45 and day 90. Macular pigment density was measured by heterochromatic flicker photometry. Serum lutein concentration in the lutein enriched egg and egg yolk-based beverage groups increased significantly (p<0.001, 76% and 77%). A strong increase in the serum zeaxanthin concentration was observed in individuals receiving zeaxanthin enriched eggs (P< 0.001, 430%). No changes were observed in macular pigment density in the various groups tested. The results indicate that daily consumption of lutein or zeaxanthin enriched egg yolks as well as an egg yolk-based beverage show increases in serum lutein and zeaxanthin levels that are comparable with a daily use of 5 mg supplements.

Trial Registration

ClinicalTrials.gov NCT00527553

Association between geographic atrophy progression and reticular pseudodrusen in eyes with dry age-related macular degeneration

PURPOSE

To evaluate geographic atrophy (GA) progression in eyes with dry AMD and to determine factors related to GA expansion, notably reticular pseudodrusen (RPD), also known as subretinal drusenoid deposits (SDD) or reticular macular disease (RMD).

METHODS

This was a retrospective cohort study of patients with dry AMD who were diagnosed with GA in at least one eye and were imaged with sequential fundus autofluorescence (FAF) and/or near infrared reflectance (NIR-R) imaging. Images were analyzed for the presence of GA within the macular region. Geographic atrophy progression was measured in the fields of a modified Wisconsin grid and spatially correlated with RPD. Factors also evaluated for association with GA progression included initial GA size and pattern.

RESULTS

The study sample included 126 eyes of 92 patients, with an average follow up of 20.4 months (SD = 11.7). At baseline, 93.6% of eyes had RPD, and the average GA area was 2.8 mm(2) (SD = 2.9). The average GA progression rate was 0.8 mm(2)/y (SD = 0.6), with a statistically significant difference between the unilobular and multilobular phenotype groups (0.3 mm(2)/y vs. 0.9 mm(2)/y, P = 0.02). Patients in the lower 50th percentile of initial GA area had a lower progression rate than patients in the upper 50th percentile (0.6 mm(2)/y vs. 1.1 mm(2)/y, P < 0.001). Geographic atrophy progression was more frequent in fields with RPD than in those without RPD (74.2% vs. 41.7%, P < 0.001).

CONCLUSIONS

The high correlation between the presence of RPD (also known as SDD or RMD) and the presence of GA, and the expansion of GA into areas with these lesions suggest that they are an early manifestation of the process leading to GA.

Antioxidative and aldose reductase-inhibitory effects of a fermentation filtrate of Rubus coreanus

Antioxidative and aldose reductase (AR)-inhibitory effects of a fermentation filtrate of Rubus coreanus (FRC) were investigated using corneal/retinal homogenate and lens cytosol, respectively. Rat corneal/retinal homogenate was treated with 50 µM FeCl₃ in the presence of FRC (3.2-100 µg/mL) for 30 min at 37℃, and thiobarbituric acid-reactive substances (TBARS) was quantified as a lipid peroxidation parameter. FRC markedly suppressed the TBARS production in a concentration-dependent manner, leading to 50% (IC₅₀) and 100% (IC₁₀₀) inhibitory concentrations of 20 and 95 µg/mL, respectively, which was similar to the effect of butylated hydroxyanisole. Activity of AR from rat lens was assayed in the presence of FRC (1-31.6 µg/mL) at 25℃ using glyceraldehyde as a substrate. FRC inhibited lens AR by 50% (IC₅₀) and 90% (IC₉₀) at approximately 2 and 31.6 µg/mL, respectively, comparable to the effect of quercetin. The results indicate that ERC could be a promising candidate for the improvement of eye injury and visual dysfunction of dry eye and diabetic patients.

Distribution of conjunctival ultraviolet autofluorescence in a population-based study: the Norfolk Island Eye Study

OBJECTIVE

The objective of this study was to describe the distribution of conjunctival ultraviolet autofluorescence (UVAF) in an adult population.

METHODS

We conducted a cross-sectional, population-based study in the genetic isolate of Norfolk Island, South Pacific Ocean. In all, 641 people, aged 15 to 89 years, were recruited. UVAF and standard (control) photographs were taken of the nasal and temporal interpalpebral regions bilaterally. Differences between the groups for non-normally distributed continuous variables were assessed using the Wilcoxon-Mann-Whitney ranksum test. Trends across categories were assessed using Cuzick's non-parametric test for trend or Kendall's rank correlation τ.

RESULTS

Conjunctival UVAF is a non-parametric trait with a positively skewed distribution. Median amount of conjunctival UVAF per person (sum of four measurements; right nasal/temporal and left nasal/temporal) was 28.2 mm(2) (interquartile range 14.5-48.2). There was an inverse, linear relationship between UVAF and advancing age (P<0.001). Males had a higher sum of UVAF compared with females (34.4 mm(2) vs 23.2 mm(2), P<0.0001). There were no statistically significant differences in area of UVAF between right and left eyes or between nasal and temporal regions.

CONCLUSION

We have provided the first quantifiable estimates of conjunctival UVAF in an adult population. Further data are required to provide information about the natural history of UVAF and to characterise other potential disease associations with UVAF. UVR protective strategies should be emphasised at an early age to prevent the long-term adverse effects on health associated with excess UVR.

Comparison of electrically-evoked ganglion cell responses in normal and degenerate retina

Retinal prosthesis is regarded as a promising method for restoring vision for the blind with retinal diseases such as retinitis pigmentosa (RP) and age related macular degeneration (ARMD). Among the several prerequisites for retinal prosthesis to succeed, one of the most important factors is the optimization of electrical stimulation applied through the prosthesis. From the previous study, we showed that the electrical characteristics of diseased retina are different from those of normal retina. For the next step, we compared electrically evoked response properties of retinal ganglion cells and established the thresholds for charge density in normal and rd1 mouse using multi-electrode array (MEA). The threshold for charge density was higher in rd1 mouse. The mean values were 254.78 microC/cm(2) and 424.62 microC/cm(2) in normal and rd1 mouse, respectively.

Implantation of episcleral electrodes via anterior orbitotomy for stimulation of the retina with induced photoreceptor degeneration: an in vivo feasibility study on a conceptual visual prosthesis

BACKGROUND

A visual prosthesis is a conceptual device designed to harnesses the function of residual afferent neurons in the visual pathway to produce artificial vision. Such implant, when applied to stimulate the vitreous surface of the retina, has proven feasible in producing the perception of light in both animals and humans. However the practicality of such device has been challenged by the difficulty of surgical access and the risks of damaging the neuroretina. Positioning a visual implant over the scleral surface of the eye could present a safer alternative but this stimulation modality has not been tested in diseased retinas and little is known about the altered electrophysiological properties of the retina in influencing the feasibility of such approach.

METHODS

Experimental photoreceptor degeneration was induced in four pigmented rabbit eyes with systematic administration of a retinotoxic agent, sodium iodate. A multielectrode array was implanted onto the surface of the sclera to target the central and peripheral parts of the retina via an anterior orbitotomy approach. The efficacy of retinal stimulation was assessed by recording electrical evoked potential over the primary visual cortex.

FINDINGS

The electrical evoked potentials were obtained from both injected and control eyes. The charge density thresholds were found to be similar in both groups and were below the bioelectric safety limit. Spatially differentiated cortical activation profiles were obtained from the central and peripheral retina and the pattern of activation corresponded to the retinotopography of the rabbit primary visual cortex.

CONCLUSION

This study proves that episcleral stimulation of the retina is a feasible alternative to intraocular approaches for the development of a visual prosthesis for retinas with photoreceptor loss.

Antiangiogenic therapy with anti-vascular endothelial growth factor modalities for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a common cause of severe vision loss in people 55 years and older.

OBJECTIVES

The objective of this review was to investigate the effects of anti-VEGF (vascular endothelial growth factor) modalities for treating neovascular AMD.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE and LILACS. We handsearched ARVO abstracts for 2006, 2007 for ongoing trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We contacted trial authors for additional data. We summarized outcomes as relative risks (RR), number needed to treat (NNT) and weighted mean differences.

MAIN RESULTS

We included five RCTs of good methodological quality. All five trials were conducted by pharmaceutical companies. An intention-to-treat analysis using the last observation carried forward method was done in most trials. Two trials compared pegaptanib versus sham. One trial compared ranibizumab versus sham, another compared ranibizumab/sham verteporfin PDT versus verteporfin PDT/sham ranibizumab, and the final trial compared ranibizumab plus verteporfin PDT versus verteporfin PDT alone. Fewer patients treated with pegaptanib lost 15 or more letters of visual acuity at one year follow-up compared to sham (pooled relative risk (RR) 0.71; 95% confidence interval (CI) 0.61 to 0.84). The NNT was 6.67 (95% CI 4.35 to 14.28) for 0.3 mg pegaptanib, 6.25 (95% CI 4.17 to 12.5) for 1 mg pegaptanib and 14.28 (95% CI 6.67 to 100) for 3 mg pegaptanib. In a trial of ranibizumab versus sham, RR for loss of 15 or more letters visual acuity at one year was 0.14 (95% CI 0.1 to 0.22) in favour of ranibizumab. The NNT was 3.13 (95% CI 2.56 to 3.84) for 0.3 mg ranibizumab and 3.13 (95% CI 2.56 to 3.84) for 0.5 mg ranibizumab. In a trial of ranibizumab versus verteporfin PDT, RR for loss of 15 or more letters at one year was 0.13 (95% CI 0.07 to 0.23) favouring ranibizumab. The NNT was 3.33 (95% CI 2.56 to 4.76) for 0.3 mg ranibizumab and 3.12 (95% CI 2.43 to 4.17) for 0.5 mg ranibizumab. In another trial of combined ranibizumab plus verteporfin PDT versus verteporfin PDT, RR for loss of 15 or more letters at one year favoured combined therapy (RR 0.3 (95% CI 0.15 to 0.60). The NNT was 4.35 (95% CI 2.78 to 11.11). Pooled RR for gain of 15 or more letters visual acuity at one year was 5.81 (95% CI 3.29 to 10.26) for ranibizumab versus sham, 6.79 (95% CI 3.41 to 13.54) for ranibizumab/sham verteporfin PDT versus verteporfin PDT/sham ranibizumab, and 4.44 (95% CI 1.40 to 14.08) for ranibizumab plus verteporfin PDT versus verteporfin PDT. Frequency of endophthalmitis in included studies was between 0.7% to 4.7% with ranibizumab and 1.3% with pegaptanib. Improvement in vision-specific quality of life was reported for both treatments.

AUTHORS' CONCLUSIONS

Pegaptanib and ranibizumab reduce the risk of visual acuity loss in patients with neovascular AMD. Ranibizumab causes gains in visual acuity in many eyes. Quality of life and cost will be important for treatment decisions. Other agents blocking VEGF are being tested in ongoing trials.

Comparison of voltage parameters for the stimulation of normal and degenerate retina

Retinal prosthesis is regarded as a promising method for restoring vision for the blind with retinal diseases such as retinitis pigmentosa (RP) and age related macular degeneration (ARMD). Among the several prerequisites for retinal prosthesis to succeed, one of the most important is the optimization of electrical stimuli applied through the prosthesis. Since the electrical characteristics of diseased retina are expected to be different with those of normal retina, we investigated different voltage parameters to stimulate normal and degenerate retina. The retinal degeneration model (rd/rd mouse) was compared against control mice. Voltage stimulations were delivered via one channel of 60 channels 8 x 8 Multi-electrode array (MEA), and ganglion cell activities were recorded with the remaining 58 channels. The parameters of voltage stimulation were set based on previous experiment with rabbit. Evoked ganglion cell responses were counted during a 10 - 20 ms time span after the stimulation. The voltage amplitudes and voltage durations were set to obtain consistent values for ganglion cell responses. When the same stimulus was applied on the rd/rd mouse, evoked ganglion cell responses were rarely observed. The distribution patterns of evoked responses appeared only on a site distant from the stimulation electrode on the rd/rd retina. Conversely, in normal retina, evenly distributed response patterns were observed. Since the charge intensity tends to decrease with the distance from stimulation electrode, the uneven patterns from the rd/rd mouse retina suggest that lower charge is required to evoke a response from rd/rd retina.

Transpupillary thermotherapy in chinese patients with choroidal neovascularization secondary to age-related macular degeneration: emphasis on the influence of power setting

PURPOSE

To perform a safety and efficacy study of transpupillary thermotherapy (TTT) in Chinese patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD).

METHODS

In a prospective study, patients with subfoveal or juxtafoveal CNV secondary to ARMD underwent TTT with fixed treatment and follow-up protocols. From August 2002 to December 2004, 26 patients (27 eyes) completed > or =6 months of follow-up and were included in this report.

RESULTS

Fourteen eyes (52%) had improved or stable visual acuity (loss of <3 lines) and 13 eyes (48%) had vision loss of > or =3 lines. The serial mean visual acuity initially decreased during follow-up, then stabilized by 6 months. In the subgroup of occult or minimally classic CNV (20 eyes), 13 eyes (65%) had improved or stable vision. The major complication of TTT included laser-related retinal pigment epithelium (RPE) atrophy in 10 eyes (37%). Six eyes had mild RPE atrophy, 4 eyes had severe RPE-choroid atrophy (macular burn). Analysis of possible risk factors for macular burn showed that 3 eyes had to have the power amplified due to nuclear sclerosis, and 1 pseudophakic eye had regular power.

CONCLUSIONS

TTT in Chinese ARMD patients with occult or minimally classic CNV, according to our protocol, prevented severe vision loss in the majority of patients, but power amplification due to medium lens opacity induced RPE atrophy or burn in some patients.

The slow wave component of retinal activity in rd/rd mice recorded with a multi-electrode array

We investigated the differences in the retinal activity between normal and degenerate retina. Multi-electrode recordings were performed in in vitro mice retinas. Only short duration (<2 ms) retinal spikes were recorded in normal mice by postnatal day 28. However, in rd/rd mice, a slow wave component with approximately 100 ms duration was also recorded along with the spikes. We attempted to understand the mechanism of this slow wave component in degenerate retina by applying various synaptic blockers. With CNQX/AP-7, the glutamate antagonist (n = 7), the slow wave component disappeared while the normally less-dominant retinal spikes became more apparent. With strychnine, the glycine antagonist (n = 3) or picrotoxin, GABA antagonist (n = 3), the amplitude of the slow wave component increased. These suggest that a stronger excitatory glutamate input from bipolar cells to ganglion cells is the main contributor to this slow wave component in rd/rd mice.

INFLUENCE OF VERTEPORFIN PHOTODYNAMIC THERAPY ON INFLAMMATION IN HUMAN CHOROIDAL NEOVASCULAR MEMBRANES SECONDARY TO AGE-RELATED MACULAR DEGENERATION

PURPOSE

To examine the short- and long-term consequences of verteporfin photodynamic therapy (PDT) on inflammation with regard to infiltration of macrophages and leukocytes and expression of thy-1 in human choroidal neovascularization membranes (CNV) secondary to age-related macular degeneration (AMD).

METHODS

Retrospective review of an interventional case series of 43 patients who underwent removal of CNV. Twenty patients were treated with PDT 3 to 246 days preoperatively. Twenty-three CNV without previous treatment were used as control. CNV were stained for CD34, CD105, cytokeratin 18, Ki-67, thy-1, an endothelial cell glycoprotein known to be upregulated only by inflammatory cytokines, CD68 (macrophages), and CD45 (common leukocyte antigen).

RESULTS

Specimens treated by PDT 3 days previously showed significantly reduced endothelial thy-1 expression (P = 0.008), leukocyte (P=0.04) and macrophage (P=0.0063) infiltration, and proliferative activity (P=0.02) compared to control CNV. Specimens at longer intervals after PDT, in contrast, disclosed a significantly increased expression of thy-1 (P=0.004), infiltration with leukocytes (P=0.044) and macrophages (P=0.01), and proliferative activity (P=0.03) compared to CNV excised 3 days after PDT.

CONCLUSIONS

The rebound effect after PDT seems to be based on an inflammatory response that contributes to enhanced proliferation. These data support the need for an anti-inflammatory therapy as adjuvant to PDT.

Characteristics of diabetic retinopathy in SDT rats

BACKGROUND

We previously reported a new diabetic strain of the Sprague-Dawley rat, named the Spontaneously Diabetic Torii (SDT) rat. The purpose of the present study was to report the histologic and ultrastructural characteristics of diabetic retinopathy (DR) in a new animal model, the SDT rat.

METHODS

Fifty-three eyes of 43 SDT rats of various ages (35-82 weeks) were examined, of which 33 underwent histopathologic examination, 15 eyes fluorescein-dextran microscopy, and five eyes the trypsin digestion method.

RESULTS

Of the 33 eyes examined histopathologically, DR was identified in 20 eyes (61%). Large retinal folds mimicking diabetic tractional retinal detachment were observed in 20 eyes (61%). Retinal hemorrhages were seen in four eyes (12%). A neovascular fibrous membrane around the iris developed in five eyes (15%), of which two eyes had a massive anterior chamber hemorrhage. Of the 15 eyes examined by fluorescein-dextran microscopy, an area of nonperfusion and/or extensive hyperfluorescence was observed in 12 eyes (80%). Of the five eyes examined using the trypsin digestion method, acellular capillaries and pericyte loss were observed in four eyes (80%). Of the 53 eyes, the previously mentioned retinal changes of DR were observed in 36 eyes (68%). The rats with DR (49-82 weeks; mean, 60 weeks) were older than the rats without DR (35-55 weeks; mean, 40 weeks) (p < 0.001).

CONCLUSION

Large retinal folds mimicking tractional retinal detachment with extensive leakage of fluorescein around the optic disk was the most prominent finding of DR in SDT rats.

Expression of VEGF and PEDF in choroidal neovascular membranes following verteporfin photodynamic therapy

PURPOSE

To examine the impact of photodynamic therapy (PDT) on pigment epithelium derived factor (PEDF) expression in human choroidal neovascularization (CNV) membranes with regard to vascular endothelial growth factor (VEGF) expression.

DESIGN

Interventional case series.

METHODS

Retrospective review of interventional case series of 42 patients (42 eyes) who underwent removal of CNV. CNV was secondary to age-related macular degeneration (AMD) in all cases. Fifteen patients were treated with PDT, 3 to 246 days before surgery. CNV were stained for CD34, CD105, cytokeratin 18, VEGF, and PEDF. Twenty-seven CNV without previous treatment were used as control.

RESULTS

Specimens without pretreatment disclosed varying degrees of vascularization, VEGF, and PEDF expression by different cells. Specimens treated by PDT, three days previously showed mostly occluded vessels lined with damaged endothelial cells (EC). In contrast, specimens excised at later time points after PDT were highly vascularized with healthy EC. This chronology was associated with an impressive VEGF immunoreactivity increased considerably in retinal pigment epithelial cells as well as significantly reduced PEDF expression in EC and stroma.

CONCLUSIONS

PDT induces a selective vascular damage in CNV. The effectiveness of PDT, however, seems to be jeopardized by a rebound effect initiated by an enhanced VEGF and reduced PEDF expression in CNV.

Effects of bevacizumab on retinal function in isolated vertebrate retina

BACKGROUND

Bevacizumab (Avastin) is a recombinant protein that targets vascular endothelial growth factor (VEGF). In vitro, bevacizumab inhibits VEGF induced cell proliferation and tissue factor production. Abnormal angiogenesis involving VEGF is a central event during the development of choroidal neovascularisation (CNV). The present study was designed to evaluate the short term toxic effects of bevacizumab on retinal function for a therapeutic intraocular application.

METHODS

Isolated bovine retinas were perfused with an oxygen pre-incubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal potential using silver/silver chloride electrodes. Bevacizumab was added in different concentrations to the nutrient solution for 45 minutes. Thereafter the retina was reperfused for 60 minutes with normal nutrient solution. The percentage of a-wave and b-wave reduction during the application of bevacizumab was calculated and compared to control recordings.

RESULTS

During the application of three different concentrations of bevacizumab (0.08 mg/ml, 0.25 mg/ml, 0.8 mg/ml) no significant reduction of the a-wave and b-wave amplitude was observed. During the washout, the ERG amplitudes were unchanged.

CONCLUSION

The present study suggests that an intraocular application of 0.25 mg/ml bevacizumab for the treatment of CNV is reasonable. No significant short term effects of bevacizumab on retinal function were detected, but long term effects cannot be excluded.

Electrical stimulation in normal and retinal degeneration (rd1) isolated mouse retina

Stimulus threshold and response latencies were measured for electrically elicited retinal ganglion cell responses in retina isolated from the eyes of normal and retinal degenerate (rd1) mice. Stimulation of the ganglion cell-side in normal retina yielded a significantly lower mean threshold and shorter latency when compared with stimulation of the photoreceptor side in normal retina. The latency of the ganglion cell-side stimulation in normal retina also proved to be significantly shorter than the latency for stimulation of the ganglion cell side in rd1 retina. Thus both the electrode positioning as well as the health of the retinal tissue play a role in the stimulating current required to elicit a retinal response.

Therapy with ribozyme to the proliferating cell nuclear antigen-ribozyme and 5-fluorouracil of experimental choroidal neovascularization in rats

PURPOSE

The aim of this study was to evaluate the efficacy of hammerhead ribozyme to the proliferating cell nuclear antigen (PCNA-Rz) and 5-fluorouracil (5-FU) in experimental choroidal neovascularization (CNV) model in rats.

METHODS

Laser was used to induce CNV in each eye of 44 rats. For angiography studies, injections of either a mixture of PCNA-Rz 10 microg/microL and 5-FU 1.5 microg/microL, versus the same dose of either drug alone versus a control injection of Hanks' Balanced Salt Solution (HBSS) were performed. We also studied this regimen to evaluate scar size and volume.

RESULTS

There was significantly less angiographic leakage for the treated eyes compared to the controls by 3.53 grading points (P = 0.0005); CNV leakage was reduced in the combination group compared to 5-FU alone by 1.75 grading units (P = 0.04) and compared to PCNARz by 2.22 grading units (P = 0.07). The scar size and volume were smaller (diameter 354.6 +/- 174.2 microm vs 477.3 +/- 157.0 microm), (thickness 52.7 +/- 43.0 microm versus 79.6 +/- 46.2 microm) with a reduction in scar volume of 44.8%.

CONCLUSIONS

Subretinal injection of PCNA-Rz and 5-FU mixture is more effective as treatment of laser-induced CNV, than either drug alone. The majority of the antiangiogenic effect is a result of 5-FU activity with a contribution by the PCNA ribozyme.

Associations between Elevated Intraocular Pressure and Glaucoma, Use of Glaucoma Medications, and 5-Year Incident Cataract

PURPOSE

To examine incident relationships between elevated intraocular pressure (IOP), open-angle glaucoma (OAG), and use of glaucoma medications with 5-year incident cataract.

DESIGN

Population-based cohort study.

PARTICIPANTS

The Australian Blue Mountains Eye Study examined 3654 participants > or =50 years old at baseline (82.4% response; 1992-1994); 2335 eligible participants were reexamined after 5 years (75.1% response; 1997-1999).

METHODS

A detailed medical and ocular history, including current medications, was taken, and a comprehensive eye examination, including applanation tonometry, automated perimetry, and lens photography, was performed at each examination. The Wisconsin system was used to grade lens photographs in assessing incident nuclear, cortical, and posterior subcapsular cataract (PSC). Data from both eyes were assessed using generalized estimating equation analyses.

MAIN OUTCOME MEASURES

Elevated IOP was defined as > or =21 mmHg. Open-angle glaucoma was diagnosed from typical glaucomatous field loss with matching optic disc cupping, without reference to IOP. Subjects without OAG or secondary or angle-closure glaucoma with IOP > 21 mmHg in either eye were classified as having ocular hypertension (OH), as were non-OAG subjects with IOP < 22 mmHg using glaucoma medications. Wisconsin levels 4 to 5 were graded as nuclear cataract, at least 5% lens involvement was graded as cortical cataract, and any PSC defined its presence.

RESULTS

The 5-year incidence of nuclear cataract was 23.4% (592/2532), or 23.1% (574/2486) after excluding subjects using glaucoma medication. A marginally significant association was found for elevated IOP or OH at baseline and incident nuclear cataract (odds ratio [OR], 1.93 [95% confidence interval (CI), 0.97-3.89], and OR, 1.83 [95% CI, 0.96-3.48], respectively) in subjects not using glaucoma medications, after multivariate adjustment. Age- and gender-adjusted analyses showed similar but statistically significant associations. The association between elevated IOP or OH and nuclear cataract was significant in multivariate analyses (OR, 2.07 [95% CI, 1.04-3.12], and OR, 1.78 [95% CI, 1.05-3.01], respectively). Use of glaucoma medications was associated with nonsignificantly increased adjusted odds for incident nuclear cataract (OR, 1.90 [95% CI, 0.92-3.92]). No associations, however, were found with incident cortical cataract or PSC.

CONCLUSIONS

Elevated IOP may increase the risk of nuclear cataract, but not that of other types. The use of glaucoma medications could magnify this risk.

The prevalence of eye disease in nursing home and non-nursing home geriatric populations

The objective of this study was to determine whether rates of eye disease among the elderly are higher for residents of nursing homes than for persons who reside elsewhere. Articles reporting the prevalence of eye disease in geriatric populations (classified as nursing home or non-nursing home) were identified through a Medline search and a search of articles' bibliographies. Identified articles were reviewed, and the relevant data compared with prevalence rates obtained from 738 residents of two nursing homes in New York City. Each of the nursing home residents received an ocular examination upon admission that determined the presence or absence of four varieties of eye disease-i.e. cataracts, age-related macular degeneration, glaucoma, and diabetic retinopathy. Demographic data were obtained through chart review. Results indicate that prevalence rates of eye disease found in geriatric nursing home populations are generally higher than those found in other geriatric populations. With the exception of the rates for diabetic retinopathy, the rates found in the combined nursing home population sampled in this study were much higher than those reported in any previous study. It is concluded that eye disease is a more serious problem for elderly residents of nursing homes than for the elderly who reside in the community. Possible reasons for this are discussed.

Different aspects of visual impairment as risk factors for falls and fractures in older men and women

Visual impairment has been implicated as a risk factor for falling and fractures, but results of previous studies have been inconsistent. The relationship between several aspects of vision and falling/fractures were examined in a prospective cohort study in 1,509 older men and women. The analyses showed that impaired vision is an independent risk factor for both recurrent falling and fractures.

INTRODUCTION

Falls and fractures are a major health problem among the elderly. Visual impairment has been implicated as a risk factor for both falls and fractures. However, results from studies are inconsistent. The inconsistency between findings can primarily be attributed to differences in the designs of these studies. Most studies have been cross-sectional or case-control studies, and many have not correctly adjusted for potential confounders. Furthermore, until now, the potential mediating effects of functional limitation, physical performance, and physical activity have not been examined.

MATERIALS AND METHODS

A total of 1,509 people was examined in 1995-1996. Contrast sensitivity was assessed with the VCTS_6000-1 chart for near vision. In addition, self-reported visual impairment was assessed by questions on recognizing faces from a distance of 4 m, reading the small print in the newspaper, and problems with glare. Furthermore, many potential confounders and mediators were assessed. Falls and fractures were assessed prospectively during a 3-year follow-up period. The associations between the vision variables and falls and fractures were examined using Cox proportional hazards analyses.

RESULTS

After adjustment for potential confounders, contrast sensitivity was shown to be associated with recurrent falling (hazard ratio [HR] = 1.5), and the question on recognizing faces was shown to be associated with fractures (HR = 3.1). Furthermore, functional limitations and physical performance were shown to be mediators in the relationship between vision variables and recurrent falling/fractures.

CONCLUSIONS

The results indicate that impaired vision is an independent risk factor for falling and fractures, but different aspects of visual functioning may have different relationships to falling and fractures.

Limited macular translocation compared with photodynamic therapy in the management of subfoveal choroidal neovascularization in age-related macular degeneration

PURPOSE

To compare the visual outcome of macular translocation (MT) versus photodynamic therapy (PDT) for subfoveal predominantly classic neovascularization in age-related macular degeneration (AMD).

DESIGN

Nonrandomized clinical trial.

METHODS

Retrospective review of 65 consecutive patients with subfoveal neovascularization due to AMD. The follow-up was at least 6 months. Main outcome criteria were final best corrected visual acuity and the gain in visual acuity.

RESULTS

A total of 29 eyes were treated with PDT with verteporfin, and 36 underwent MT with chorioscleral infolding. Both groups were similar for age, refraction, and lesion size. The initial visual acuity was lower in the MT group than in the PDT group (20/200 versus 20/100). Mean follow-up was 11 months for the PDT group and 14 months for the MT group. The mean displacement of the fovea after translocation was 1,274 microm (range, 250 to 1,900 microm). Mean number of retreatment by PDT was 2.5. At 1 year, both groups had the same final visual acuity (20/200), but the improvement was more favorable in the MT group (gain of 0.7 line in the MT group versus loss of 3.4 lines in the PDT group, P =.007). One eye in the PDT group (4.3%) had a gain of 3 lines or more versus eight eyes (38%) in the MT group; the lesion size was larger in the PDT group than in MT group (P =.036).

CONCLUSION

In this retrospective study, MT seemed to allow a better preservation of visual acuity than PDT in subfoveal neovascularization due to AMD. Further larger and controlled studies are required.

Zeaxanthin in combination with ascorbic acid or alpha-tocopherol protects ARPE-19 cells against photosensitized peroxidation of lipids

The antioxidant action of carotenoids is believed to involve quenching of singlet oxygen and scavenging of reactive oxygen radicals. However, the exact mechanism by which carotenoids protect cells against oxidative damage, particularly in the presence of other antioxidants, remains to be elucidated. This study was carried out to examine the ability of exogenous zeaxanthin alone and in combination with vitamin E or C, to protect cultured human retinal pigment epithelium cells against oxidative stress. The survival of ARPE-19 cells, subjected to merocyanine 540-mediated photodynamic action, was determined by the MTT test and the content of lipid hydroperoxides in photosensitized cells was analyzed by HPLC with electrochemical detection. We found that zeaxanthin-supplemented cells, in the presence of either alpha-tocopherol or ascorbic acid, were significantly more resistant to photoinduced oxidative stress. Cells with added antioxidants exhibited increased viability and accumulated less lipid hydroperoxides than cells without the antioxidant supplementation. Such a synergistic action of zeaxanthin and vitamin E or C indicates the importance of the antioxidant interaction in efficient protection of cell membranes against oxidative damage induced by photosensitized reactions.