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Purpose The complement pathway may play a key role in the pathogenesis of age-related macular degeneration (AMD). The safety and efficacy of avacincaptad pegol (Zimura, IVERIC bio Inc, New York, NY), a C5 inhibitor, were assessed in participants with geographic atrophy (GA) secondary to AMD (GATHER1 Study). Design International, prospective, randomized, double-masked, sham-controlled, pivotal phase 2/3 clinical trial. Participants A total of 286 participants with GA secondary to AMD. Main Outcome Measures The primary efficacy endpoint was the mean rate of change in GA over 12 months measured by fundus autofluorescence (FAF) at 3 timepoints: baseline, month 6, and month 12. Results The reduction in the mean rate of GA growth (square root transformation) over 12 months was 27.4% (P = 0.0072) for the avacincaptad pegol 2 mg cohort and 27.8% (P = 0.0051) for the avacincaptad pegol 4 mg cohort compared with their corresponding sham cohorts. The results for both dose groups were statistically significant. Avacincaptad pegol was generally well tolerated after monthly administration over 12 months. There were no avacincaptad pegol–related adverse events (AEs) or inflammation. Further, there were no ocular serious AEs (SAEs) and no cases of endophthalmitis. The most frequent ocular AEs were related to the injection procedure. Conclusions Intravitreal administration of avacincaptad pegol 2 mg and 4 mg led to a significant reduction of GA growth in eyes with AMD over a 12-month period. Because C5 inhibition theoretically preserves C3 activity, it may offer additional safety advantages. A second confirmatory pivotal clinical trial is underway to confirm the efficacy and safety of avacincaptad pegol in slowing the GA growth (GATHER2 Study).

PURPOSE To provide a concise overview for ophthalmologists and practicing retina specialists of available clinical evidence of manipulating the angiopoietin/tyrosine kinase with immunoglobulin-like and endothelial growth factor-like domains (Tie) pathway and its potential as a therapeutic target in retinal vascular diseases. METHODS A literature search for articles on the angiopoietin/Tie pathway and molecules targeting this pathway that have reached Phase 2 or 3 trials was undertaken on PubMed, Association for Research in Vision and Ophthalmology meeting abstracts (2014-2019), and ClinicalTrials.gov databases. Additional information on identified pipeline drugs was obtained from publicly available information on company websites. RESULTS The PubMed and Association for Research in Vision and Ophthalmology meeting abstract search yielded 462 results, of which 251 publications not relevant to the scope of the review were excluded. Of the 141 trials related to the angiopoietin/Tie pathway on ClinicalTrials.gov, seven trials focusing on diseases covered in this review were selected. Vision/anatomic outcomes from key clinical trials on molecules targeting the angiopoietin/Tie pathway in patients with retinal vascular diseases are discussed. CONCLUSION Initial clinical evidence suggests a potential benefit of targeting the angiopoietin/Tie pathway and vascular endothelial growth factor-A over anti-vascular endothelial growth factor-A monotherapy alone, in part due to of the synergistic nature of the pathways.

The purpose of this study was the synthesis of novel degradable polymer-based devices capable of releasing an encapsulated agent in a controlled manner with specific interest for use as drug delive...

Purpose To establish a process to evaluate and standardize a state-of-the-art nomenclature for reporting neovascular age-related macular degeneration (AMD) data. Design Consensus meeting. Participants An international panel of retina specialists, imaging and image reading center experts, and ocular pathologists. Methods During several meetings organized under the auspices of the Macula Society, an international study group discussed and codified a set nomenclature framework for classifying the subtypes of neovascular AMD and associated lesion components. Main Outcome Measures A consensus classification of neovascular AMD. Results The study group created a standardized working definition of AMD. The components of neovascular AMD were defined and subclassified. Disease consequences of macular neovascularization were delineated. Conclusions The framework of a consensus nomenclature system, a definition of AMD, and a delineation of the subtypes of neovascular AMD were developed. Establishing a uniform set of definitions will facilitate comparison of diverse patient groups and different studies. The framework presented is modified and updated readily, processes that are anticipated to occur on a periodic basis. The study group suggests that the consensus standards outlined in this article be used in future reported studies of neovascular AMD and clinical practice.

Purpose To describe the defining features of incomplete retinal pigment epithelium (RPE) and outer retinal atrophy (iRORA), a consensus term referring to the OCT-based anatomic changes often identified before the development of complete RPE and outer retinal atrophy (cRORA) in age-related macular degeneration (AMD). We provide descriptive OCT and histologic examples of disease progression. Design Consensus meeting. Participants Panel of retina specialists, including retinal imaging experts, reading center leaders, and retinal histologists. Methods As part of the Classification of Atrophy Meeting (CAM) program, an international group of experts analyzed and discussed longitudinal multimodal imaging of eyes with AMD. Consensus was reached on a classification system for OCT-based structural alterations that occurred before the development of atrophy secondary to AMD. New terms of iRORA and cRORA were defined. This report describes in detail the CAM consensus on iRORA. Main Outcome Measures Defining the term iRORA through OCT imaging and longitudinal cases showing progression of atrophy, with histologic correlates. Results OCT was used in cases of early and intermediate AMD as the base imaging method to identify cases of iRORA. In the context of drusen, iRORA is defined on OCT as (1) a region of signal hypertransmission into the choroid, (2) a corresponding zone of attenuation or disruption of the RPE, and (3) evidence of overlying photoreceptor degeneration. The term iRORA should not be used when there is an RPE tear. Longitudinal studies confirmed the concept of progression from iRORA to cRORA. Conclusions An international consensus classification for OCT-defined anatomic features of iRORA are described and examples of longitudinal progression to cRORA are provided. The ability to identify these OCT changes reproducibly is essential to understand better the natural history of the disease, to identify high-risk signs of progression, and to study early interventions. Longitudinal data are required to quantify the implied risk of vision loss associated with these terms. The CAM classification provides initial definitions to enable these future endeavors, acknowledging that the classification will be refined as new data are generated.

To determine photoreceptor function in subjects with drusen only and non-foveal nascent geographic atrophy (nGA) intermediate age-related macular degeneration.In this cross-sectional study, 60 eyes from 33 subjects, 30 with drusen only and 30 with non-foveal nGA determined by spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) underwent testing for best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), and qCSF algorithm (area under log contrast sensitivity function [AULCSF]) under both standard photopic and low-luminance (LL AULCSF) conditions. Areas of nGA-associated hypo-autofluorescence (hypo-AF) were graded.In the drusen group, visual acuity (VA) = 81 letters ± 3 (mean ± SD), LLVA = 65 letters ± 4, AULCSF = 0.99 ± 0.0.5, and LL AULCSF = 0.38 ± 0.04, whereas in the nGA group, VA = 77 ± 4 letters, LLVA = 61± 4, AULCSF = 0.87 ± 0.09, and LL AULCSF = 0.28 ± 0.06. Multivariate analysis of variance among the LLVA, AULCSF, and LL AULCSF did not demonstrate a statistical difference (P = .167), whereas LL AULCSF analyzed by analysis of variance demonstrated a significant difference between the 2 groups (P = .037). Linear regressions demonstrated significant relationships between BCVA and AULCSF in both the drusen and nGA groups (r = 0.83, P10The use of LL AULCSF and certain features of FAF should be considered in clinical trials of intermediate age-related macular degeneration. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Faricimab is a novel anti-angiopoietin-2 and anti-vascular endothelial growth factor (VEGF) bispecific antibody with high affinities and specificities for both VEGF and angiopoietin-2. It is postulated that targeting angiogenic factors and inflammatory pathways in addition to the VEGF pathway will increase treatment durability and improve outcomes. The phase 3 YOSEMITE (ClinicalTrials.gov identifier, NCT03622580) and RHINE (ClinicalTrials.gov identifier, NCT03622593) trials are designed to assess efficacy, safety, and durability of faricimab compared with aflibercept in patients with diabetic macular edema (DME). The trials evaluate a personalized treatment interval (PTI) approach to address heterogeneity in treatment response among patients with DME.Two identically designed, global, double-masked, randomized, controlled phase 3 trials (YOSEMITE and RHINE).Adults with center-involving DME secondary to type 1 or 2 diabetes mellitus.These studies were designed to evaluate 3 treatment groups: faricimab 6.0 mg dosed either at fixed dosing every 8 weeks after initial treatment with 6 intravitreal doses at 4-week intervals, or faricimab 6.0 mg dosed according to PTI after initial treatment with 4 every-4-week doses, compared with aflibercept 2.0 mg dosed every 8 weeks after 5 initial every-4-week doses. The primary end point of the studies was change from baseline in best-corrected visual acuity at 1 year, averaged over weeks 48, 52, and 56. Secondary end points included anatomic, durability, and patient-reported outcomes. Safety outcomes included incidence and severity of ocular and nonocular adverse events. The PTI is a protocol-defined flexible regimen based on the treat-and-extend concept, which allowed up to every-16-week adjustable dosing based on objective and standardized criteria. The PTI design aimed to maximize therapeutic results while minimizing treatment burden.We describe the rationale for the study design and the novel PTI (up to every-16-week adjustable dosing) approach for treatment with faricimab.YOSEMITE and RHINE enrolled 940 and 951 patients, respectively. Results from each study will be reported separately.YOSEMITE and RHINE were the first registrational trials in retinal disease to incorporate an objective PTI regimen, allowing for up to every-16-week adjustable dosing with a dual angiopoietin-2 and VEGF-A inhibitor, faricimab 6.0 mg, for treatment of DME.

To assess the effectiveness of an active learning approach to measuring the contrast sensitivity function (CSF) in patients with various degrees of dry age-related macular degeneration (AMD) under multiple luminance conditions.Cross-sectional study.Patients with AMD (26 intermediate AMD, 19 AMD with subretinal drusenoid deposits [SDD], 20 geographic atrophy [GA]) and 23 age-matched controls were tested with the Manifold Contrast Vision Meter (Adaptive Sensory Technology) and the qCSF algorithm, which applies active learning to estimate a model of the CSF's global shape. Testing was performed under conditions of standard and low luminance. For each AMD severity, the area under log CSF (AULCSF) and contrast sensitivities at individual spatial frequencies were calculated for analysis. Low-luminance deficits (LLDs) for visual acuity (VA) and AULCSF were calculated as the difference between standard and low luminance values.Progressive decreases in AULCSF were observed as disease severity increased. For standard luminance, pairwise comparisons revealed significant differences between control/intermediate AMD (P.0005), control/SDD (P.0005), control/GA (P.0005), and intermediate AMD/GA (P.005). Similarly, for low luminance, pairwise comparisons revealed significant differences between the controls and each disease group (all P.0005), in addition to significant differences between intermediate AMD/SDD (P.005), and intermediate AMD/GA (P.005). No correlations were found between LLD VA and LLD AULCSF in any AMD groups.Contrast sensitivity measured via qCSF under both standard- and low-luminance conditions correlates with advancing stages of dry AMD. The interaction between luminance and contrast sensitivity appears to reflect a different aspect of visual function than the interaction between luminance and VA.

The complement pathway may play a key role in the pathogenesis of age-related macular degeneration (AMD). The safety and efficacy of avacincaptad pegol (Zimura, IVERIC bio Inc, New York, NY), a C5 inhibitor, were assessed in participants with geographic atrophy (GA) secondary to AMD (GATHER1 Study).International, prospective, randomized, double-masked, sham-controlled, pivotal phase 2/3 clinical trial.A total of 286 participants with GA secondary to AMD.The primary efficacy endpoint was the mean rate of change in GA over 12 months measured by fundus autofluorescence (FAF) at 3 timepoints: baseline, month 6, and month 12.The reduction in the mean rate of GA growth (square root transformation) over 12 months was 27.4% (P = 0.0072) for the avacincaptad pegol 2 mg cohort and 27.8% (P = 0.0051) for the avacincaptad pegol 4 mg cohort compared with their corresponding sham cohorts. The results for both dose groups were statistically significant. Avacincaptad pegol was generally well tolerated after monthly administration over 12 months. There were no avacincaptad pegol-related adverse events (AEs) or inflammation. Further, there were no ocular serious AEs (SAEs) and no cases of endophthalmitis. The most frequent ocular AEs were related to the injection procedure.Intravitreal administration of avacincaptad pegol 2 mg and 4 mg led to a significant reduction of GA growth in eyes with AMD over a 12-month period. Because C5 inhibition theoretically preserves C3 activity, it may offer additional safety advantages. A second confirmatory pivotal clinical trial is underway to confirm the efficacy and safety of avacincaptad pegol in slowing the GA growth (GATHER2 Study).

Purpose To determine whether emixustat hydrochloride (emixustat) reduces the rate of enlargement of geographic atrophy (GA) compared with placebo in subjects with age-related macular degeneration (AMD) and to evaluate the safety and tolerability of emixustat over 24 months of treatment. Design Multicenter, randomized, double-masked, placebo-controlled, phase 2b/3 clinical trial. Participants Patients with GA secondary to AMD, a visual acuity score of at least 35 letters, and GA with a total area of 1.25 to 18 mm2 were enrolled. Methods Subjects were randomized (1:1:1:1) to emixustat 2.5 mg, 5 mg, 10 mg, or placebo, administered orally once daily for 24 months. Visits included screening, baseline, and months 1, 2, 3, 6, 9, 12, 15, 18, 21, 24, and 25. Main Outcome Measures The primary efficacy end point was the mean annual growth rate of total GA area in the study eye, as measured by a central reading center using fundus autofluorescence (FAF) images. The change from baseline in normal luminance best-corrected visual acuity (NL-BCVA) was a secondary efficacy end point. Results Of 508 randomized subjects, 320 completed the study. Demographics and baseline characteristics were comparable between treatment groups. On average, GA lesions in the study eye grew at a similar rate in each group (emixustat: 1.69 to 1.84 mm2/year; placebo: 1.69 mm2/year; P ≥ 0.81). Changes in NL-BCVA were also comparable between groups. Subjects with a larger low luminance deficit (LLD) at baseline (≥20 letters) demonstrated a more rapid growth of GA over 24 months. No relationship was observed between the risk-allele status of the AMD-associated single-nucleotide polymorphisms tested and the growth rate of GA. The most common adverse events in emixustat-treated subjects were delayed dark adaptation (55%), chromatopsia (18%), visual impairment (15%), and erythropsia (15%). Conclusions Emixustat did not reduce the growth rate of GA in AMD. The most common adverse events were ocular in nature and likely related to the drug’s mechanism of action. Data gained from this study over a 2-year period add to the understanding of the natural history of GA and the baseline characteristics affecting the growth rate of GA.

Purpose To develop consensus terminology and criteria for defining atrophy based on OCT findings in the setting of age-related macular degeneration (AMD). Design Consensus meeting. Participants Panel of retina specialists, image reading center experts, retinal histologists, and optics engineers. Methods As part of the Classification of Atrophy Meetings (CAM) program, an international group of experts surveyed the existing literature, performed a masked analysis of longitudinal multimodal imaging for a series of eyes with AMD, and reviewed the results of this analysis to define areas of agreement and disagreement. Through consensus discussions at 3 meetings over 12 months, a classification system based on OCT was proposed for atrophy secondary to AMD. Specific criteria were defined to establish the presence of atrophy. Main Outcome Measures A consensus classification system for atrophy and OCT-based criteria to identify atrophy. Results OCT was proposed as the reference standard or base imaging method to diagnose and stage atrophy. Other methods, including fundus autofluorescence, near-infrared reflectance, and color imaging, provided complementary and confirmatory information. Recognizing that photoreceptor atrophy can occur without retinal pigment epithelium (RPE) atrophy and that atrophy can undergo an evolution of different stages, 4 terms and histologic candidates were proposed: complete RPE and outer retinal atrophy (cRORA), incomplete RPE and outer retinal atrophy, complete outer retinal atrophy, and incomplete outer retinal atrophy. Specific OCT criteria to diagnose cRORA were proposed: (1) a region of hypertransmission of at least 250 μm in diameter, (2) a zone of attenuation or disruption of the RPE of at least 250 μm in diameter, (3) evidence of overlying photoreceptor degeneration, and (4) absence of scrolled RPE or other signs of an RPE tear. Conclusions A classification system and criteria for OCT-defined atrophy in the setting of AMD has been proposed based on an international consensus. This classification is a more complete representation of changes that occur in AMD than can be detected using color fundus photography alone. Longitudinal information is required to validate the implied risk of vision loss associated with these terms. This system will enable such future studies to be undertaken using consistent definitions.

Purpose RG7716 is a novel bispecific antibody that simultaneously binds vascular endothelial growth factor (VEGF) and another key angiogenic factor, angiopoietin 2. A phase I study of intravitreal RG7716 was conducted to evaluate single-dose and multiple-dose safety in patients with neovascular age-related macular degeneration (AMD). Design Open-label, single and multiple ascending-dose study. Participants Twenty-four patients diagnosed with neovascular AMD with best-corrected visual acuity (BCVA) of 20/40 to 20/400 (Snellen equivalent) and refractory subfoveal choroidal neovascularization defined as leakage on fluorescein angiography or fluid on spectral-domain optical coherence tomography despite 3 or more intravitreal anti-VEGF treatments in the preceding 6 months. Methods Single intravitreal doses of 0.5 mg, 1.5 mg, 3 mg, and 6 mg RG7716 were administered in stepwise dose-escalation groups, each with 3 patients. In the multiple-dose phase, 6 patients were enrolled and received 3 treatments each of 3 mg and 6 mg RG7716. Main Outcome Measures Safety and tolerability, changes in baseline BCVA, and central subfield thickness (CST). Results There were no dose-limiting toxicities in either the single-dose or multiple-dose group. Treatment-emergent ocular adverse events were mild. There was a single withdrawal and 1 serious adverse event, both deemed to be unrelated to the study drug by principal investigators. In the combined single-dose groups and in the 6-mg multiple-dose group, BCVA increased from baseline to 28 days after the last dose administration by a median of 7 letters (range, 0–18 letters; n = 11) and 7.5 letters (range, 3–18 letters; n = 6), respectively. The corresponding median reduction from baseline in CST were 42 μm (range, −101 to 10 μm; n = 11) and −117 μm (range, −252 to −7 μm; n = 6), respectively. After multiple 3-mg RG7716 doses, no changes were observed in either BCVA (median, −0.5 letters; range, −9 to 8 letters; n = 6) or CST (median, −9 μm; range, −188 to −1 μm; n = 6). Conclusions RG7716 was well tolerated and exhibited an overall favorable safety profile, with evidence of improvements in BCVA and anatomic parameters. These data support further evaluation of RG7716 in phase II trials.

PURPOSE: To summarize the results of 2 consensus meetings (Classification of Atrophy Meeting [CAM]) on conventional and advanced imaging modalities used to detect and quantify atrophy due to late-stage non-neovascular and neovascular age-related macular degeneration (AMD) and to provide recommendations on the use of these modalities in natural history studies and interventional clinical trials. DESIGN: Systematic debate on the relevance of distinct imaging modalities held in 2 consensus meetings. PARTICIPANTS: A panel of retina specialists. METHODS: During the CAM, a consortium of international experts evaluated the advantages and disadvantages of various imaging modalities on the basis of the collective analysis of a large series of clinical cases. A systematic discussion on the role of each modality in future studies in non-neovascular and neovascular AMD was held. MAIN OUTCOME MEASURES: Advantages and disadvantages of current retinal imaging technologies and recommendations for their use in advanced AMD trials. RESULTS: Imaging protocols to detect, quantify, and monitor progression of atrophy should include color fundus photography (CFP), confocal fundus autofluorescence (FAF), confocal near-infrared reflectance (NIR), and high-resolution optical coherence tomography volume scans. These images should be acquired at regular intervals throughout the study. In studies of non-neovascular AMD (without evident signs of active or regressed neovascularization [NV] at baseline), CFP may be sufficient at baseline and end-of-study visit. Fluorescein angiography (FA) may become necessary to evaluate for NV at any visit during the study. Indocyanine-green angiography (ICG-A) may be considered at baseline under certain conditions. For studies in patients with neovascular AMD, increased need for visualization of the vasculature must be taken into account. Accordingly, these studies should include FA (recommended at baseline and selected follow-up visits) and ICG-A under certain conditions. CONCLUSIONS: A multimodal imaging approach is recommended in clinical studies for the optimal detection and measurement of atrophy and its associated features. Specific validation studies will be necessary to determine the best combination of imaging modalities, and these recommendations will need to be updated as new imaging technologies become available in the future.

Background/purpose Age-related macular degeneration is the most prevalent cause of permanent vision loss in the developed world. Drusenoid pigment epithelial detachments are a biomarker of age-related macular degeneration disease progression and typically result in poor visual prognosis. Low luminance visual acuity (LLVA) has been previously been shown to correlate with the severity of age-related macular degeneration. However, the degree of spontaneous improvement of this functional outcome is still under investigation. Methods Observational clinical case report. Results A drusenoid pigment epithelial detachment that increased in size with the development of hyperreflective foci spontaneously improved with restoration of normal foveal contour over the span of 41 months without progression to geographic atrophy or choroidal neovascularization. Although best-corrected visual acuity remained stable both before and after the pigment epithelial detachment resolution, low luminance visual acuity decreased from a baseline of 59 (20/63 -1) to 39 (20/160 -1) letters over 17 months. However, over the subsequent 24 months, low luminance visual acuity improved by 35 letters to 74 letters (20/32 -2). Conclusion Drusenoid pigment epithelial detachments can resolve without treatment. Low luminance visual acuity seems to correlate with the anatomic improvement and can improve spontaneously by more than six lines of vision.

Age-related macular degeneration (AMD) is one of the major causes of vision loss in the elderly in most developed countries. Among other causes, oxidative stress in the retinal pigment epithelium (RPE) has been hypothesized to be a major driving force of AMD pathology. Oxidative stress could be treated by antioxidant administration into the RPE cells. However, to achieve high in-vivo efficacy of an antioxidant, it is imperative that the agent be able to penetrate the tissues and cells. Evidence suggests that lipophilicity governs cellular penetrance. Out of many antioxidant candidates, N-acetyl-L-cysteine (a prodrug of L-cysteine) (NAC) is a potent antioxidant as the bioavailability of the parent drug, L-cysteine, determines the production of glutathione; the universal antioxidant that regulates ROS. To increase the lipophilicity, four ester derivatives of N-acetylcysteine: N-acetylcysteine methyl ester, N-acetylcysteine ethyl ester, N-acetylcysteine propyl ester, and N-acetylcysteine butyl ester were synthesized. To mimic in vitro AMD conditions, hydroquinone, a component of cigarette smoke, was used as the oxidative insult. Cytosolic and mitochondrial protection against oxidative stress were tested using cytosolic and mitochondrial specific assays. The results provide evidence that these lipophilic cysteine prodrugs provide increased protection against oxidative stress in human RPE cells compared with NAC.

Background/objective A subset of neovascular age-related macular degeneration (nvAMD) subjects appears to be refractory to the effects of anti-VEGF treatment and require frequent intravitreal injections. The vascular phenotype of the choroidal neovascular (CNV) lesions may contribute to the resistance. Animal studies of CNV lesions have shown that cells originating from bone marrow are capable of forming varying cell types in the lesions. This raised the possibility of a similar cell population in human nvAMD subjects. Materials and methods Blood draws were obtained from subjects with active nvAMD while patients were receiving standard of care anti-VEGF injections. Subjects were classified as refractory or non-refractory to anti-VEGF treatment based on previous number of injections in the preceding 12 months. Peripheral blood mononuclear cells (PBMCs) were isolated and CD34-positive cells purified using magnetic bead sorting. The isolated cells were expanded in StemSpan SFEM media to increase cell numbers. After expansion, the cells were split and plated in either endothelial or mesenchymal promoting conditions. Phenotype analysis was performed via qPCR. Results There was no significant difference in the number of PBMCs and CD34-positive cells between refractory and non-refractory nvAMD subjects. The growth pattern distribution between endothelial and mesenchymal media conditions were very similar between refractory and non-refractory subjects. qPCR and immunostaining demonstrated positive expression of endothelial markers in endothelial media, and markers such as NG2 and αSMA in mesenchymal media. However, analysis of subsequent samples from AMD subjects demonstrated high variability in both the numbers and differentiation properties of this cell population. Conclusions CD34+ cells can be isolated from nvAMD subjects and show both endothelial and pericyte-like characteristics after differentiation in certain media conditions. However, nvAMD subjects show high variability in both numbers of cells and differentiation characteristics in repeat sampling. This variability highlights the importance of taking multiple samples from nvAMD subjects for any clinical trials focused on biomarkers for the disease.

A subset of neovascular age-related macular degeneration (nvAMD) subjects appears to be refractory to the effects of anti-VEGF treatment and require frequent intravitreal injections. Prokineticin-2 (Bv8) expression in CD11b(+) cells has been linked to anti-VEGF response. We have developed a reproducible method to quantify gene expression in circulating CD11b + cells. Utilizing this method we tested the hypothesis that high Bv8 expression in circulating CD11b(+) cells is associated with anti-VEGF refractoriness in nvAMD patients. Two groups of nvAMD subjects undergoing treatment with anti-VEGF agents were recruited and classified as refractory or non-refractory to anti-VEGF treatment (n = 33 for each group). Two blood draws were obtained from each subject 1-9 months apart. Peripheral blood mononuclear cells (PBMCs) were isolated and CD11b(+) cells were purified via magnetic bead separation. RNA was purified, and relative expression of Bv8 among the subjects was compared via quantitative PCR analysis. Utilizing this approach no significant difference was detected in the mean LogRQ values between the first and second blood draws (t-test, p = 0.826) indicating low intra-patient variability and demonstrating good reproducibility of the assay. There was no significant difference in Bv8 expression between nvAMD subjects classified as refractory versus non-refractory. We were unable to find a correlation between Bv8 expression in CD11b + cells and anti-VEGF refractoriness in human nvAMD subjects. Relatively high expression in Bv8 in these subjects did not correlate with clinical treatment history, as measured by the frequency of injections. Utilizing this well characterized technique, studies are underway to examine alternative gene expression profiles in various circulating cell populations that may contribute to anti-VEGF refractoriness.

Purpose This study investigated the effects of esterification and increased lipophilicity on cellular penetration, accumulation and retention in ARPE-19-nic cells using ester functionalized rhodamine B dyes. Methods Rhodamine B was esterified to generate four dyes with increasing lipophilicity. Cellular uptake, retention and mitochondrial localization were investigated in vitro using ARPE-19-nic cells using direct intracellular and extracellular and mitochondrial fluorescence quantitation, confocal and high-resolution live cell imaging and co-localization with Mito-GFP. Results Cellular penetrance, mitochondrial accumulation, and retention of the esterified dyes were increased in ARPE-19-nic cells compared with the nonesterified parent dye by direct fluorescence quantitation. Imaging demonstrated intracellular accumulation was confined to mitochondria as confirmed by colocalization with Mito-GFP. Conclusions Esterification is an effective way to increase lipophilicity of a dye to improve cellular penetration of chemical entities. These observations may be key to improving retinal drug delivery for retinal pigment epithelium-based diseases. Translational relevance Understanding the intracellular distribution of drugs into retinal pigment epithelium cells is a critical component for identifying potential therapies for retinal pigment epithelium-based diseases.

Geographic atrophy (GA) is a progressive, advanced form of age-related macular degeneration leading to visual function impairment and irreversible vision loss. Standard clinical tests to evaluate visual function in patients with GA provide poor anatomic-functional correlation, whereas fundus imaging does not assess the visual function deficit. Microperimetry is a psychophysical visual function test that spatially maps retinal sensitivity and allows for identification of correlation of anatomic features with visual function. In this review, we present an overview of mesopic microperimetry for GA, including commercially available microperimetry devices, strategies to capture a mesopic microperimetry test, and strategies to assess and interpret microperimetry data in patients with GA. We demonstrate the importance of microperimetry data for assessing GA progression and for evaluating visual function loss through anatomic-functional correlations. Although valuable, current microperimetry tests require an extensive time commitment from the patient and examiner, and the development of faster, more reproducible and accessible methods is important to enable broader use of microperimetry in both clinical and research settings.

Purpose To determine the relationship between central drusen volume and low-luminance deficit (LLD) in visual acuity (VA) in patients with intermediate age-related macular degeneration (AMD). Methods In this cross-sectional study, 42 patients with intermediate AMD underwent testing for VA and low-luminance VA (LLVA), as well as spectral-domain optical coherence tomography. LLD was calculated as the difference between VA and LLVA. Central drusen volume was measured in the central 3 mm of the macula, defined as the volume between the inner border of the retinal pigment epithelium and Bruch's membrane. Results Mean ± standard deviation (SD) LLD was 0.32 ± 0.12 logMAR and mean ± SD drusen volume was 0.18 ± 0.09 mm3. No linear relationship was identified between central 3 mm drusen volume and LLD (P = 0.215). R2 for the bivariate linear model was 0.038 (95% confidence interval 0–0.222). Limitation of the analysis to drusen volumes measured in the central 1 mm of the macula did not impact results (R2 = 0.075), nor did incorporation of lens status into the model (R2 = 0.067) or censoring of patients with nonfoveal subretinal drusenoid deposits (R2 = 0.071). Conclusions The amount of drusen within the central 3 mm of the macula does not appear to be related to LLD in intermediate AMD. These measures may be manifestations of different underlying pathophysiological mechanisms. Translational Relevance Understanding relationships between markers for AMD progression may help guide development of improved clinical grading scales for AMD.

Purpose To evaluate pazopanib eye drops in subjects with active subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). Design Multicountry, randomized, parallel-group, double-masked, active and placebo-controlled, dose-ranging study of eye drops. Participants A total of 510 subjects (93% white; 58% female; mean age, 75.3 years) whose AMD was previously managed by anti–vascular endothelial growth factor intravitreal injections. Methods Treatments administered for 52 weeks included placebo eye drops instilled 4 times daily (n = 73); pazopanib 5 mg/ml instilled 3 (n = 72) or 4 times daily (n = 74); pazopanib 10 mg/ml instilled 2 (n = 73), 3 (n = 73), or 4 times daily (n = 72); or ranibizumab injection administered once every 4 weeks (n = 73). In addition, for all eye drop treatment groups, open-label ranibizumab was administered as needed. Main Outcome Measures The main outcome measures were best-corrected visual acuity (BCVA) and injection frequency assessed at week 52. Safety was assessed every 4 weeks and pazopanib plasma concentrations were determined at weeks 4 and 24. Results At week 52, pazopanib, with allowance for as-needed ranibizumab injections, was noninferior to monthly ranibizumab as well as to as-needed ranibizumab administered with placebo eye drops in maintaining BCVA (estimated BCVA gains of 0.3–1.8 vs. 1.4 vs. 0.2 letters, respectively). Pazopanib treatment did not reduce as-needed ranibizumab injections by ≥50% (prespecified efficacy criterion). At week 52, there were no clinically meaningful changes from baseline in retinal thickness or morphology, CNV size, or lesion characteristics on optical coherence tomography or fluorescein angiography. Complement factor H genotype had no effect on the responses to pazopanib and/or ranibizumab (BCVA, injection rate, or optical coherence tomography/fluorescein angiography changes). Steady-state concentrations of pazopanib in plasma seemed to be reached by week 4. The most common ocular adverse events related to pazopanib and ranibizumab were application site pain (3%) and injection site hemorrhage (1%), respectively. No treatment-related serious adverse events were reported. Conclusions Pazopanib was well tolerated. Daily pazopanib eye drops in neovascular AMD subjects did not result in therapeutic benefit beyond that obtained with ranibizumab alone.

To determine whether emixustat hydrochloride (emixustat) reduces the rate of enlargement of geographic atrophy (GA) compared with placebo in subjects with age-related macular degeneration (AMD) and to evaluate the safety and tolerability of emixustat over 24 months of treatment.Multicenter, randomized, double-masked, placebo-controlled, phase 2b/3 clinical trial.Patients with GA secondary to AMD, a visual acuity score of at least 35 letters, and GA with a total area of 1.25 to 18 mmSubjects were randomized (1:1:1:1) to emixustat 2.5 mg, 5 mg, 10 mg, or placebo, administered orally once daily for 24 months. Visits included screening, baseline, and months 1, 2, 3, 6, 9, 12, 15, 18, 21, 24, and 25.The primary efficacy end point was the mean annual growth rate of total GA area in the study eye, as measured by a central reading center using fundus autofluorescence (FAF) images. The change from baseline in normal luminance best-corrected visual acuity (NL-BCVA) was a secondary efficacy end point.Of 508 randomized subjects, 320 completed the study. Demographics and baseline characteristics were comparable between treatment groups. On average, GA lesions in the study eye grew at a similar rate in each group (emixustat: 1.69 to 1.84 mmEmixustat did not reduce the growth rate of GA in AMD. The most common adverse events were ocular in nature and likely related to the drug's mechanism of action. Data gained from this study over a 2-year period add to the understanding of the natural history of GA and the baseline characteristics affecting the growth rate of GA.

Background Topical bevacizumab is a potential treatment modality for corneal neovascularization, and several recent studies have demonstrated its efficacy. No previous study of the pharmacokinetics of topical bevacizumab has been performed in human eyes. The purpose of this study is to investigate the pharmacokinetics of topical administration of bevacizumab in human eyes, and also to compare the pharmacokinetics of intravitreal bevacizumab injections with previously reported data. Methods Twenty-two (22 eyes) were included in this study, and divided into four groups: eight patients received topical bevacizumab and aqueous samples were obtained 1 hour later during cataract extraction surgery (group 1), eight patients received topical bevacizumab and vitreous samples were obtained 1 day later during pars-plana vitrectomy (PPV) (group 2), three patients received intravitreal bevacizumab and vitreous samples were obtained during PPV (group 3). Vitreous samples from three patients who received no bevacizumab served as controls (group 4). All samples underwent enzyme-linked immunosorbent assay to detect bevacizumab. Results No bevacizumab was detected in the aqueous or vitreous of any topically treated eyes. The mean vitreal half-life for intravitreally injected bevacizumab was 4.9 days in four non-vitrectomized eyes and 0.66 days in one previously vitrectomized eye. Conclusions Topically administered bevacizumab does not penetrate the cornea into the anterior chamber and vitreous cavity, indicating that topical use for treating corneal neovascularization has minimal risk of intraocular penetration and adverse events related to intraocular vascular endothelial growth factor inhibition. The half-life following intravitreal bevacizumab injection measured in this study is comparable to that of previous reports, and includes the first demonstration of a significantly reduced half-life following intravitreal injection in a previously vitrectomized eye.

Purpose The accuracy of predicting conversion from early-stage age-related macular degeneration (AMD) to the advanced stages of choroidal neovascularization (CNV) or geographic atrophy (GA) was evaluated to determine whether inclusion of clinically relevant genetic markers improved accuracy beyond prediction using phenotypic risk factors alone. Design Cohort study. Participants White, non-Hispanic subjects participating in the Age-Related Eye Disease Study (AREDS) sponsored by the National Eye Institute consented to provide a genetic specimen. Of 2415 DNA specimens available, 940 were from disease-free subjects and 1475 were from subjects with early or intermediate AMD. Methods DNA specimens from study subjects were genotyped for 14 single nucleotide polymorphisms (SNPs) in genes shown previously to associate with CNV: ARMS2 , CFH , C3 , C2 , FB , CFHR4 , CFHR5, and F13B . Clinical demographics and established disease associations, including age, sex, smoking status, body mass index (BMI), AREDS treatment category, and educational level, were evaluated. Four multivariate logistic models (phenotype; genotype; phenotype + genotype; and phenotype + genotype + demographic + environmental factors) were tested using 2 end points (CNV, GA). Models were fitted using Cox proportional hazards regression to use time-to-disease onset data. Main Outcome Measures Brier score (measure of accuracy) was used to identify the model with the lowest prediction error in the training set. The most accurate model was subjected to independent statistical validation, and final model performance was described using area under the receiver operator curve (AUC) or C-statistic. Results The CNV prediction models that combined genotype with phenotype with or without age and smoking revealed superior performance (C-statistic = 0.96) compared with the phenotype model based on the simplified severity scale and the presence of CNV in the nonstudy eye (C-statistic = 0.89; P ARMS2 genotype had less of an impact on the prediction of GA compared with CNV. Conclusions Inclusion of genotype assessment improves CNV prediction beyond that achievable with phenotype alone and may improve patient management. Separate assessments should be used to predict progression to CNV and GA because genetic markers and smoking status do not equally predict both end points. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.

Retinal pigment epithelium (RPE)-derived membranous debris named blebs, may accumulate and contribute to sub-RPE deposit formation, which is the earliest sign of age-related macular degeneration (AMD). Oxidative injury to the RPE might play a significant role in AMD. However, the underlying mechanisms are unknown. We previously reported that hydroquinone (HQ), a major pro-oxidant in cigarette smoke, foodstuff, and atmospheric pollutants, induces actin rearrangement and membrane blebbing in RPE cells as well as sub-RPE deposits in mice. Here, we show for the first time that phosphorylated Heat shock protein 27 (Hsp27), a key regulator of actin filaments dynamics, is up-regulated in RPE from patients with AMD. Also, HQ-induced nonlethal oxidative injury led to Hsp27mRNA up-regulation, dimer formation, and Hsp27 phosphorylation in ARPE-19 cells. Furthermore, we found that a cross talk between p38 and extracellular signal-regulated kinase (ERK) mediates HQ-induced Hsp27 phosphorylation and actin aggregate formation, revealing ERK as a novel upstream mediator of Hsp27 phosphorylation. Finally, we demonstrated that Hsp25, p38, and ERK phosphorylation are increased in aging C57BL/6 mice chronically exposed to HQ, whereas Hsp25 expression is decreased. Our data suggest that phosphorylated Hsp27 might be a key mediator in AMD and HQ-induced oxidative injury to the RPE, which may provide helpful insights into the early cellular events associated with actin reorganization and bleb formation involved in sub-RPE deposits formation relevant to the pathogenesis of AMD.

Importance There are no approved drug treatments for autosomal dominant retinitis pigmentosa, a relentlessly progressive cause of adult and childhood blindness. Objectives To evaluate the potential efficacy and assess the safety of orally administered valproic acid (VPA) in the treatment of autosomal dominant retinitis pigmentosa. Design, Setting, and Participants Multicenter, phase 2, prospective, interventional, placebo-controlled, double-masked randomized clinical trial. The study took place in 6 US academic retinal degeneration centers. Individuals with genetically characterized autosomal dominant retinitis pigmentosa were randomly assigned to receive treatment or placebo for 12 months. Analyses were intention-to-treat. Interventions Oral VPA 500 mg to 1000 mg daily for 12 months or placebo. Main Outcomes and Measures The primary outcome measure was determined prior to study initiation as the change in visual field area (assessed by the III4e isopter, semiautomated kinetic perimetry) between baseline and month 12. Results The mean (SD) age of the 90 participants was 50.4 (11.6) years. Forty-four (48.9%) were women, 87 (96.7%) were white, and 79 (87.8%) were non-Hispanic. Seventy-nine participants (87.8%) completed the study (42 [95.5%] received placebo and 37 [80.4%] received VPA). Forty-two (46.7%) had a rhodopsin mutation. Most adverse events were mild, although 7 serious adverse events unrelated to VPA were reported. The difference between the VPA and placebo arms for mean change in the primary outcome was −150.43 degree2(95% CI, −290.5 to −10.03;P = .035). Conclusions and Relevance This negative value indicates that the VPA arm had worse outcomes than the placebo group. This study brings to light the key methodological considerations that should be applied to the rigorous evaluation of treatments for these conditions. This study does not provide support for the use of VPA in the treatment of autosomal dominant retinitis pigmentosa. Trial Registration ClinicalTrials.gov Identifier:NCT01233609

To investigate the movement of intravitreally injected human serum albumin nanoparticles (HSA-NP) with respect to nanoparticle surface charge and retinal injury.HSA-NPs were developed by a desolvation technique. HSA-NPs were cationized by covalent coupling of hexamethylenediamine on the particle surface. Either anionic or cationic HSA-NPs were injected to determine the effect of surface charge on intravitreal nanoparticle movement. HSA-NPs were injected intravitreally into both normal and laser photocoagulated eyes to examine the effect of the integrity of retinal tissue on the retinal penetration. The retinal penetration of fluorescence labeled anionic HSA-NPs was investigated by confocal microscopy.Anionic particles (-33.3+/-6.1 mV) more easily diffused through the 3-dimensional vitreal network of collagen fibrils than did their cationic counterparts (11.7+/-7.2 mV). In the laser photocoagulated retina, more HSA-NPs were detected in the choroidal space, compared to the normal retina. The immunohistochemical studies indicated that HSA-NPs were taken up into Müller cells.The movement of intravitreal nanoparticles depended on both nanoparticles surface charge and retinal injury. The Müller cells might play an important role in the retinal penetration of nanoparticles. The anionic HSA-NP is a promising drug or gene delivery carrier to the sub-retinal space and RPE.

This study assessed the safety, tolerability, and pharmacodynamics of emixustat hydrochloride (ACU-4429), a novel visual cycle modulator, in subjects with geographic atrophy associated with dry age-related macular degeneration.Subjects were randomly assigned to oral emixustat (2, 5, 7, or 10 mg once daily) or placebo (3:1 ratio) for 90 days. Recovery of rod photoreceptor sensitivity after a photobleach was measured by electroretinography. Safety evaluations included analysis of adverse events and ophthalmic examinations.Seventy-two subjects (54 emixustat and 18 placebo) were evaluated. Emixustat suppressed rod photoreceptor sensitivity in a dose-dependent manner. Suppression plateaued by Day 14 and was reversible within 7 days to 14 days after drug cessation. Most systemic adverse events were not considered treatment related. Dose-related ocular adverse events (chromatopsia, 57% emixustat vs. 17% placebo and delayed dark adaptation, 48% emixustat vs. 6% placebo) were mild to moderate in severity, and the majority resolved on study or within 7 days to 14 days after study drug cessation. Reversibility of these adverse events with long-term administration, however, is undetermined.In this Phase II study, emixustat produced a dose-dependent reversible effect on rod function that is consistent with the proposed mechanism of action. These results support further testing of emixustat for the treatment of geographic atrophy associated with dry age-related macular degeneration.

It is generally believed that photoreceptor integrity is related to the ellipsoid zone appearance in optical coherence tomography (OCT) B-scans. Algorithms and software were developed for viewing and analyzing the ellipsoid zone. The software performs the following: (a), automated ellipsoid zone isolation in the B-scans, (b), en-face view of the ellipsoid-zone reflectance, (c), alignment and overlay of (b) onto reflectance images of the retina, and (d), alignment and overlay of (c) with microperimetry sensitivity points. Dataset groups were compared from normal and dry age related macular degeneration (DAMD) subjects. Scalar measurements for correlation against condition included the mean and standard deviation of the ellipsoid zone’s reflectance. The imageprocessing techniques for automatically finding the ellipsoid zone are based upon a calculation of optical flow which tracks the edges of laminated structures across an image. Statistical significance was shown in T-tests of these measurements with the population pools separated as normal and DAMD subjects. A display of en-face ellipsoid-zone reflectance shows a clear and recognizable difference between any of the normal and DAMD subjects in that they show generally uniform and nonuniform reflectance, respectively, over the region near the macula. Regions surrounding points of low microperimetry (μP) sensitivity have nonregular and lower levels of ellipsoid-zone reflectance nearby. These findings support the idea that the photoreceptor integrity could be affecting both the ellipsoid-zone reflectance and the sensitivity measurements.

Rituximab is a monoclonal antibody directed against the CD20 B-cell antigen and is approved for the treatment of B-cell lymphoma. We investigated the pharmacokinetics of rituximab following intravitreal administration to assess the feasibility of treating primary intraocular lymphoma. Intravitreal injections of rituximab 0.1 ml (1 mg) were performed in rabbits. Drug concentrations in the aqueous and vitreous humor were measured at intervals from 2 to 17 days after administration. The half-life of the total amount of rituximab in the two compartments was calculated to be 4.7 days. The aqueous and vitreous humor drug levels decayed in parallel maintaining an average ratio of approximately seven. Fitting the data to a two-compartment model yielded a clearance from the aqueous humor of 1.2 microl/min. The clearance was less than the reported rate of aqueous humor outflow indicating that elimination by this route could have been sufficient to account for the disappearance of the drug from the eye. The duration of time over which sustained levels of rituximab were achieved suggest that intravitreal administration warrants further investigation as an approach to treating vitreous and anterior chamber infiltrates in patients with primary intraocular lymphoma.

The pathogenesis of age-related macular degeneration (AMD) is still unknown but there is growing evidence that a combination of both oxidative injury and genetic factors may play a role. One particle hypothesis proposes that dysregulation of multiple genes in response to an oxidative injury could contribute to the development of AMD. While direct examination of ocular cells from AMD patients is difficult, AMD also appears to have a systemic component. Therefore, as is the case with other central nervous diseases, peripheral sites may also manifest any underlying genetic abnormalities. For the present study, biopsy-derived fibroblasts from 4 patients with the early form and 4 patients with the late form of AMD and 3 age-matched control patients were grown in culture and treated with a nonlethal dose of the oxidative stimulus menadione. Gene expression patterns were quantitatively and qualitatively examined using Human Genome U95A GeneChips (Affymetrix) and verified by real-time PCR analysis. In response to the oxidative injury 755 genes were found to be upregulated at least twofold in one of the patients groups. Cluster analysis of expression profiles detected six patterns of dysregulation initiated by oxidative injury specific for the disease groups (98 genes total). Clusters of genes dysregulated by the sublethal oxidative injury in either early and/or late AMD groups were further categorized by overrepresentation of GO "biological process" categories using Expression Analysis Systematic Explorer (EASE) software. This approach demonstrated that four major functional gene groups including inflammatory/innate immune response, transcriptional regulation, cell cycle, and proliferation were significantly overrepresented (Fisher test ranging from 0.0393 to 0.00018) in both AMD patients groups in response to the oxidative injury. Despite the small number of patients in the study, specific biological and statistical differences in gene expression profiles between control and AMD patients were identified but only in the presence of an environmental stimulus.

To investigate relationships between clinical measures of central visual function and NEI-VFQ-25 Near and Distance Activities subscales in patients with diabetic retinopathy.Clinic-based, cross-sectional, observational study.The NEI-VFQ-25 was administered to 170 people with type 1 or 2 diabetes before an ocular examination that included visual acuity, contrast sensitivity, and central visual fields. Multiple linear regression and exact multiple logistic regression were used to assess the relationship between poor acuity (69 letters), poor contrast sensitivity (1.5 log units), and abnormal visual fields (mean deviationor = -5dB) and NEI-VFQ-25 subscale scores.Final multivariable linear models explained a beta = 4.7 letter difference (Por = .001) for each 25-point Near Activities subscale score difference. Similar effects were observed for the Distance Activities subscale, although the magnitudes of regression and partial correlation coefficients were lower (beta = 3.3 letters, Por = .01). Final logistic regression models on abnormal clinical categories of central visual function demonstrated relationships only with the Near Activities subscale. For a 1-point change in Near Activities subscale score, the odds of obtaining a poor score for visual acuity, central visual fields, and contrast sensitivity changed by 0.08 (Por = .001), 0.07 (Por = .05), and 0.12 (Por = .001), respectively.NEI-VFQ-25 Near and Distance Activities subscales demonstrate utility as measures of central visual function in persons with type 1 or 2 diabetes. Low scores on the NEI-VFQ-25 may reflect poor central visual fields and contrast sensitivity in addition to poor visual acuity.

Choroidal neovascularization (CNV) is characterized by the subretinal invasion of a pathologic new vessel complex from the choriocapillaris. Although CNV is traditionally considered to consist of endothelial cells, the cellular population of CNV is likely more complex in nature, comprising several different cell types. In addition, recent studies suggest that the CNV cell population has a dual origin (circulating versus resident populations). In this study we sought to determine the contribution and origin of different cell types in experimental CNV. Laser-induced CNV was performed on chimeric mice generated by reconstituting C57BL/6 mice with bone marrow from green fluorescent protein (GFP)-transgenic mice. In these mice, bone marrow-derived cells are GFP-labeled. Immunofluorescence staining was used to examine both flatmount preparations of the choroid and cross sections of the posterior pole for macrophages, endothelial cells, vascular smooth muscle cells, retinal pigment epithelial (RPE) cells, lymphocytes, or neutrophils at day 3, 7, 14 and 28 post-laser (n=5 per group). Cell types present in CNV included macrophages (20% of the cells in CNV), endothelial cells (25%), vascular smooth muscle cells (11%), RPE cells (12%) and non-labeled cells (32%). The macrophage population was mostly derived from circulating monocytes at all timepoints studied (70% were GFP labeled), while endothelial and vascular smooth muscle cells were partly bone marrow derived (50-60% were GFP labeled), and RPE cells appeared to be entirely derived from preexisting tissue resident cells. These results demonstrate that bone marrow-derived progenitor cells contribute significantly to the vascular and inflammatory components of CNV. Knowledge of the cellular composition and origin might help understand the pathogenic mechanisms controlling CNV severity as well as indicate potential targets for therapeutic intervention.

Ensuring optimum delivery of therapeutic agents in the eye requires detailed information about the transport mechanisms and elimination pathways available. This knowledge can guide the development of new drug delivery devices. In this study, we investigated the movement of a drug surrogate, Gd-DTPA (Magnevist) released from a polymer-based implant in rabbit vitreous using T1-weighted magnetic resonance imaging (MRI). Intensity values in the MRI data were converted to concentration by comparison with calibration samples. Concentration profiles approaching pseudosteady state showed gradients from the implant toward the retinal surface, suggesting that diffusion was occurring into the retinal-choroidal-scleral (RCS) membrane. Gd-DTPA concentration varied from high values near the implant to lower values distal to the implant. Such regional concentration differences throughout the vitreous may have clinical significance when attempting to treat ubiquitous eye diseases using a single positional implant. We developed a finite element mathematical model of the rabbit eye and compared the MRI experimental concentration data with simulation concentration profiles. The model utilized a diffusion coefficient of Gd-DTPA in the vitreous of 2.8 x 10(-6) cm2 s(-1) and yielded a diffusion coefficient for Gd-DTPA through the simulated composite posterior membrane (representing the retina-choroidsclera membrane) of 6.0 x 10(-8) cm2 s(-1). Since the model membrane was 0.03-cm thick, this resulted in an effective membrane permeability of 2.0 x 10(-6) cm s(-1). Convective movement of Gd-DTPA was shown to have minimal effect on the concentration profiles since the Peclet number was 0.09 for this system.

Objectives To evaluate the long-term natural history and effects of laser photocoagulation treatment in patients with diabetic retinopathy. Design Follow-up study of the 214 surviving patients enrolled originally at the Johns Hopkins Clinical Center for the Early Treatment Diabetic Retinopathy Study (ETDRS), which was a clinical trial designed to evaluate the role of laser photocoagulation and aspirin treatment in patients with diabetic retinopathy. Methods Early Treatment Diabetic Retinopathy Study patients enrolled in the Johns Hopkins Clinical Center had complete eye examinations, including best-corrected visual acuity measurements, fundus photographs, and medical questionnaires throughout the 7-year study. They had the same examinations at the final long-term follow-up visit at the National Eye Institute, National Institutes of Health, 13 to 19.5 years after the initial laser photocoagulation (median, 16.7 years). Main outcome measures The major outcomes were mortality and the rates of moderate and severe vision loss. The secondary outcomes were progression of diabetic retinopathy and need for other eye surgery. Results Of the 214 patients who were alive at the end of the original ETDRS in 1989, 130 (61%) were deceased at the time of the re-examination. Of the 84 who were alive, 71 (85%) were examined at their long-term follow-up visit at the National Institutes of Health. At the long-term follow-up examination, 42% had visual acuity of 20/20 or better, and 84% had visual acuity of 20/40 or better in the better eye. Compared with baseline, 20% of patients had moderate vision loss (loss of 3 lines or more vision) in the better eye at follow-up. Only one patient had visual acuity of 20/200 bilaterally. He had visual acuity loss secondary to age-related macular degeneration. No patient had severe vision loss (worse than 5/200). All the initially untreated eyes of patients who had severe nonproliferative diabetic retinopathy or worse by the time of the ETDRS closeout visit of the original study received scatter photocoagulation treatment. Focal photocoagulation was performed in 43% bilaterally and 22% unilaterally. Cataract surgery was performed in 31% of the patients, vitrectomy in 17%, and glaucoma surgery in one patient. Conclusions As previously reported, the mortality rate of patients with diabetic retinopathy is much higher than that of the general population. For those who survived, aggressive follow-up, with treatment when indicated, seems to be associated with maintenance of good long-term visual acuity for most patients. The need for laser scatter photocoagulation with long-term follow-up seems to be high.

In the present study, the pathways involved in oxidant-induced cell death of a primary cell of the retina, ARPE-19, were investigated and compared with a leukemic cell, U937 cells. Both ARPE-19 and U937 cells exhibited similar viability when exposed to menadione. At lethal doses, both cell lines demonstrated extensive membrane blebbing. However, although U937 cells exhibited caspase-3, -9 PARP cleavage and 200 bp laddering, no such cleavage or laddering was noted in ARPE-19 cells. Furthermore, addition of exogenous cytochrome c and ATP to a cell-free system again resulted in cleavage of caspase-3 and -9 in extracts of U937 but not ARPE cells. Further studies in ARPE-19 cells undergoing menadione-induced cell death demonstrated mitochondrial membrane depolarization, release of cytochrome c, nuclear translocation of apoptosis-inducing factor and subsequent 50 kilo-base pair laddering, and nuclear shrinkage. All of these findings were abrogated by the pretreatment of ARPE-19 cells with hepatocyte growth factor/scatter factor. These findings demonstrate the complex nature of cell death in primary cells of the retina and highlight the role of caspase-independent signals, growth factors and intracellular survival factors in programmed cell death pathways.

Sixteen human immunodeficiency virus (HIV)-infected patients with inactive cytomegalovirus (CMV) retinitis who had discontinued systemic anti-CMV therapy while receiving highly active antiretroviral therapy (HAART) were prospectively observed. Fifteen patients developed immune recovery uveitis (IRU); 3 of the patients developed extensive retinal neovascularization, 1 of whom required vitrectomy for recurrent vitreous hemorrhages. These late complications indicate a need for continued ophthalmologic follow-up of HIV-infected patients who have a history of CMV retinitis, even for individuals who have not required anti-CMV therapy for >4 years.

Purpose Corticosteroids remain the mainstay of treatment for inflammatory diseases almost 80 years after their first clinical use. Topical ophthalmic formulations of corticosteroids have been available to treat disease of the anterior segment of the eye, but the approval of corticosteroids to treat vitreoretinal diseases, including vein occlusion, diabetic macular edema, and uveitis, has occurred only recently. Although most diseases respond to corticosteroid therapy, some patients are resistant to this therapy and side effects, including cataract and elevated intraocular pressure, can limit their use. The purpose of this review is to detail the basic science of corticosteroids focusing on differences in potency, drug delivery, pharmacokinetics, and gene activation, and how these differences affect safety and efficacy in the treatment of diabetic macular edema. Methods A review was conducted of basic science and pharmacology of the corticosteroids used to treat diabetic macular edema. Results Clinically available corticosteroids not only have differing potency and pharmacokinetics, but also activate different genes in different target tissues. These differences are associated with distinct efficacy, pharmacokinetic, and safety profiles. It is important to understand these differences in selecting corticosteroids to treat diabetic macular edema. Conclusions Recent advances in our understanding of the basic science of corticosteroids can explain clinical differences in these agents regarding efficacy and safety. Importantly, this understanding should allow the future discovery of additional novel corticosteroids to treat diabetic macular edema.

To investigate mechanisms of apical sorting in the secretory pathway of epithelial cells, we expressed varying amounts of the 165 amino acid isoform of vascular endothelial growth factor (VEGF 165 ) and transforming growth factor β1 (TGF-β1) via replication defective adenoviruses. Apical sorting of both proteins was efficient at low expression levels but saturated or was reversed at high expression levels. High expression levels of TGF-β1 were effective at competing VEGF 165 out of the apical pathway; however, VEGF 165 did not compete out TGF-β1. Tunicamycin inhibition experiments showed that the apical polarity of VEGF 165 was independent of N -glycosylation. We conclude that the apical sorting of these two molecules is a saturable, signal-mediated process, involving competition for apical sorting receptors. The sorting of the two proteins does not appear to involve N -glycans as sorting signals, or lectin sorters. The observations are particularly relevant to gene therapy because they demonstrate that overexpression of a transgene can result in undesirable missorting of the encoded protein.

Gene therapy may become a powerful therapeutic modality in the treatment of both ocular inflammatory disease and as a means of preventing rejection following tissue transplantation. By directly introducing into ocular cells genes that encode proteins capable of down-regulating the immune response, gene therapy has potential for both therapy and as a method for studying mechanisms of disease. While marked and rapid advances in the study of gene therapy have been realized, technical questions regarding the appropriate vector or the choice of efficacious immunomodulatory protein still remain.

Retinal pigment epithelial (RPE) cells apically polarize proteins that are basolateral in other epithelia. This reversal may be generated by the association of RPE with photoreceptors and the interphotoreceptor matrix, postnatal expansion of the RPE apical surface, and/or changes in RPE sorting machinery. We compared two proteins exhibiting reversed, apical polarities in RPE cells, neural cell adhesion molecule (N-CAM; 140-kD isoform) and extracellular matrix metalloproteinase inducer (EMMPRIN), with the cognate apical marker, p75-neurotrophin receptor (p75-NTR). N-CAM and p75-NTR were apically localized from birth to adulthood, contrasting with a basolateral to apical switch of EMMPRIN in developing postnatal rat RPE. Morphometric analysis demonstrated that this switch cannot be attributed to expansion of the apical surface of maturing RPE because the basolateral membrane expanded proportionally, maintaining a 3:1 apical/basolateral ratio. Kinetic analysis of polarized surface delivery in MDCK and RPE-J cells showed that EMMPRIN has a basolateral signal in its cytoplasmic tail recognized by both cell lines. In contrast, the basolateral signal of N-CAM is recognized by MDCK cells but not RPE-J cells. Deletion of N-CAM's basolateral signal did not prevent its apical localization in vivo. The data demonstrate that the apical polarity of EMMPRIN and N-CAM in mature RPE results from suppressed decoding of specific basolateral signals resulting in randomized delivery to the cell surface.