Change in area of geographic atrophy in the Age-Related Eye Disease Study: AREDS report number 26

Maximum Reading Speed in Patients With Geographic Atrophy Secondary to Age-Related Macular Degeneration

Purpose

Geographic atrophy (GA) is an advanced form of age-related macular degeneration. GA often initially spares the center of the fovea, leading to a functional disconnect between reading speed and distance visual acuity. This study was designed to determine the correlation between baseline GA lesion size, change in lesion size, and maximum reading speed (MRS) over 18 months.

Methods

Post hoc analysis included US patients from the phase 2 Mahalo study of intravitreal lampalizumab with Minnesota low-vision reading (MNREAD) assessments at baseline and 6, 12, and 18 months. Binocular MRS was assessed using MNREAD Acuity Charts and GA lesion size by fundus autofluorescence. Correlations were estimated using Spearman's rank correlation coefficient.

Results

Seventy-seven patients were included in the analysis. Baseline MRS correlated with baseline GA lesion size (correlation coefficient, -0.47; 95% confidence interval, -0.63 to -0.28; P < 0.0001). In patients with lesions ≥10 mm2 (four disc areas), the proportion reading below a nonfluent level (MRS, <40 words/min) at baseline (26.5%) increased to 64.7% by 18 months, versus patients with lesions <10 mm2 (baseline, 9.3%; 18 months, 7.0%). MRS declined by a median of 40.9% (interquartile range [IQR], -70.2 to -6.9) in patients with ≥2.5 mm2 lesion growth versus 8.2% (IQR, -34.6 to 11.0) in patients with <2.5 mm2 lesion growth from baseline to 18 months.

Conclusions

These findings suggest that baseline GA lesion size and magnitude of lesion growth are associated with a decline in MRS over time and support the use of MRS as an evaluation of functional vision in patients with GA.

Systemic Disease and Long-term Intraocular Pressure Mean, Peak, and Variability in Nonglaucomatous Eyes

PURPOSE

Elevated intraocular pressure (IOP) is a well-known risk factor in glaucoma development and progression. As most glaucoma risk factors are not modifiable, IOP remains the sole focus of medical and surgical therapy. Identifying modifiable factors and their effects on IOP, such as systemic diseases, is therefore of interest. The objective is to assess the long-term, longitudinal relationship between systemic diseases and IOP mean, peak, and variability, including diabetes, hypertension, body mass index (BMI), and smoking status.

DESIGN

Secondary analysis of randomized clinical trial data.

METHODS

Longitudinal IOP and systemic disease data from the Age-Related Eye Disease Study (AREDS), a randomized clinical trial of high-dose antioxidants, was analyzed.

STUDY POPULATION

A total of 3909 older participants without a reported diagnosis of glaucoma or glaucoma treatment during AREDS with up to 12 years of annual IOP and systemic disease data.

MAIN OUTCOME MEASURES

Independent systemic disease risk factors associated with IOP.

RESULTS

Univariate analysis identified numerous systemic disease factors associated with IOP mean, peak, and variability. Longitudinal adjusted models identified diabetes, obesity, and systolic hypertension as significantly associated with increased IOP, while systemic beta-blocker use was inversely associated.

CONCLUSIONS

Results demonstrate a relationship between multiple systemic diseases and IOP; moreover, they demonstrate that systemic diseases influence additional parameters beyond mean IOP, such as IOP peak and variability. Although only to be taken within the context of IOP, these population-level trends reveal potentially modifiable factors in IOP control, and are particularly important in the context of increasing obesity and diabetes prevalence rates in American adults.

Progression of Geographic Atrophy in Age-related Macular Degeneration: AREDS2 Report Number 16

PURPOSE

To analyze the prevalence, incidence, and clinical characteristics of eyes with geographic atrophy (GA) in age-related macular degeneration (AMD), including clinical and genetic factors affecting enlargement.

DESIGN

Prospective cohort study within a controlled clinical trial.

PARTICIPANTS

Age-Related Eye Disease Study 2 (AREDS2) participants, aged 50-85 years.

METHODS

Baseline and annual stereoscopic color fundus photographs were evaluated for GA presence and area. Analyses included GA prevalence and incidence rates, Kaplan-Meier rates, mixed-model regression, and multivariable analysis of the square root of GA, area adjusted for covariates, including clinical/imaging characteristics and genotype.

MAIN OUTCOME MEASURES

(1) Presence or development of GA; (2) change in the square root of GA area over time.

RESULTS

At baseline, 517 eyes (6.2%) of 411 participants (9.8%) had pre-existing GA (without neovascular AMD), with the following characteristics: 33% central, 67% noncentral; and the following configurations: 36% small, 26% solid/unifocal, 24% multifocal, 9% horseshoe/ring, and 6% indeterminate. Of the remaining 6530 eyes at risk, 1099 eyes (17.3%) of 883 participants developed incident GA without prior neovascular disease during mean follow-up of 4.4 years. The Kaplan-Meier rate of incident GA was 19% of eyes at 5 years. In eyes with incident GA, 4-year risk of subsequent neovascular AMD was 29%. In eyes with incident noncentral GA, 4-year risk of central involvement was 57%. GA enlargement rate (following square root transformation) was similar in eyes with pre-existing GA (0.29 mm/year; 95% confidence interval 0.27-0.30) and incident GA (0.28 mm/year; 0.27-0.30). In the combined group, GA enlargement was significantly faster with noncentrality, multifocality, intermediate baseline size, and bilateral GA (P < 0.0001 for interaction in each case) but not with AREDS2 treatment assignment (P = 0.33) or smoking status (P = 0.05). Enlargement was significantly faster with ARMS2 risk (P < 0.0001), C3 non-risk (P = 0.0002), and APOE non-risk (P = 0.001) genotypes.

CONCLUSIONS

Analyses of AREDS2 data on natural history of GA provide representative data on GA evolution and enlargement. GA enlargement, which was influenced by lesion features, was relentless, resulting in rapid central vision loss. The genetic variants associated with faster enlargement were partially distinct from those associated with risk of incident GA. These findings are relevant to further investigations of GA pathogenesis and clinical trial planning.

Emixustat Hydrochloride for Geographic Atrophy Secondary to Age-Related Macular Degeneration: A Randomized Clinical Trial

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.

Macular Atrophy in the HARBOR Study for Neovascular Age-Related Macular Degeneration

PURPOSE

To evaluate macular atrophy (MA) presence in the 24-month HARBOR study (NCT00891735) for neovascular age-related macular degeneration (AMD).

DESIGN

Post hoc analysis of a phase 3 multicenter, prospective, randomized, double-masked, active treatment-controlled clinical trial.

PARTICIPANTS

Evaluable subjects (N = 1095) with subfoveal choroidal neovascularization (CNV) secondary to neovascular AMD treated with ranibizumab 0.5 mg or 2.0 mg monthly or pro re nata (PRN).

METHODS

Fluorescein angiograms (FAs) and color fundus photographs at baseline and months 3, 12, and 24 were retrospectively graded by masked graders for MA: well-defined areas of depigmentation with increased choroidal vessel visibility, diameter ≥250 μm, corresponding to flat areas of well-demarcated staining on FA, excluding atrophy associated with retinal pigment epithelium tears. Atrophy immediately within, adjacent, and nonadjacent to CNV lesions was included.

MAIN OUTCOME MEASURES

Macular atrophy incidence, best-corrected visual acuity (BCVA).

RESULTS

At baseline, MA was detected in 11.2% (123/1095) of study eyes. At month 24, 29.4% (229/778) of eyes without baseline atrophy had detectable MA. Eyes with and without baseline MA had significant mean BCVA gains from baseline at month 24 (letters [95% confidence interval]: +6.7 [4.1-9.3]; +9.1 [8.0-10.2], respectively). Among eyes with and without MA at month 24, mean month 24 BCVA was 62.0 [60.3-63.7] and 64.7 [63.2-66.3] letters, respectively. Baseline risk factors for month 24 MA presence included intraretinal cysts (hazard ratio [HR], 2.45 [1.76-3.42]) and fellow eye atrophy (HR, 2.02 [1.42-2.87]); subretinal fluid was associated with a lower MA risk (HR, 0.50 [0.33-0.74]). Ranibizumab dose was not associated with MA development. Monthly versus PRN treatment trended toward an association with MA (HR, 1.29 [0.99-1.68]), but was not statistically significant.

CONCLUSIONS

New MA was detected in 29% of study eyes after 24 months of treatment. Clinically significant BCVA gains were achieved with MA present over 24 months. Baseline subretinal fluid absence, intraretinal cyst presence, and fellow eye atrophy presence were associated with month 24 MA presence. With existing data, the benefits of ranibizumab for neovascular AMD outweighed the risk of MA development over 24 months in HARBOR, although outcomes >2 years were not evaluated.

Automated Grading of Age-Related Macular Degeneration From Color Fundus Images Using Deep Convolutional Neural Networks

Importance

Age-related macular degeneration (AMD) affects millions of people throughout the world. The intermediate stage may go undetected, as it typically is asymptomatic. However, the preferred practice patterns for AMD recommend identifying individuals with this stage of the disease to educate how to monitor for the early detection of the choroidal neovascular stage before substantial vision loss has occurred and to consider dietary supplements that might reduce the risk of the disease progressing from the intermediate to the advanced stage. Identification, though, can be time-intensive and requires expertly trained individuals.

Objective

To develop methods for automatically detecting AMD from fundus images using a novel application of deep learning methods to the automated assessment of these images and to leverage artificial intelligence advances.

Design, Setting, and Participants

Deep convolutional neural networks that are explicitly trained for performing automated AMD grading were compared with an alternate deep learning method that used transfer learning and universal features and with a trained clinical grader. Age-related macular degeneration automated detection was applied to a 2-class classification problem in which the task was to distinguish the disease-free/early stages from the referable intermediate/advanced stages. Using several experiments that entailed different data partitioning, the performance of the machine algorithms and human graders in evaluating over 130 000 images that were deidentified with respect to age, sex, and race/ethnicity from 4613 patients against a gold standard included in the National Institutes of Health Age-related Eye Disease Study data set was evaluated.

Main Outcomes and Measures

Accuracy, receiver operating characteristics and area under the curve, and kappa score.

Results

The deep convolutional neural network method yielded accuracy (SD) that ranged between 88.4% (0.5%) and 91.6% (0.1%), the area under the receiver operating characteristic curve was between 0.94 and 0.96, and kappa coefficient (SD) between 0.764 (0.010) and 0.829 (0.003), which indicated a substantial agreement with the gold standard Age-related Eye Disease Study data set.

Conclusions and Relevance

Applying a deep learning-based automated assessment of AMD from fundus images can produce results that are similar to human performance levels. This study demonstrates that automated algorithms could play a role that is independent of expert human graders in the current management of AMD and could address the costs of screening or monitoring, access to health care, and the assessment of novel treatments that address the development or progression of AMD.

The Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration

Geographic atrophy (GA) is an advanced form of age-related macular degeneration (AMD) that leads to progressive and irreversible loss of visual function. Geographic atrophy is defined by the presence of sharply demarcated atrophic lesions of the outer retina, resulting from loss of photoreceptors, retinal pigment epithelium (RPE), and underlying choriocapillaris. These lesions typically appear first in the perifoveal macula, initially sparing the foveal center, and over time often expand and coalesce to include the fovea. Although the kinetics of GA progression are highly variable among individual patients, a growing body of evidence suggests that specific characteristics may be important in predicting disease progression and outcomes. This review synthesizes current understanding of GA progression in AMD and the factors known or postulated to be relevant to GA lesion enlargement, including both affected and fellow eye characteristics. In addition, the roles of genetic, environmental, and demographic factors in GA lesion enlargement are discussed. Overall, GA progression rates reported in the literature for total study populations range from 0.53 to 2.6 mm²/year (median, ∼1.78 mm²/year), assessed primarily by color fundus photography or fundus autofluorescence (FAF) imaging. Several factors that could inform an individual's disease prognosis have been replicated in multiple cohorts: baseline lesion size, lesion location, multifocality, FAF patterns, and fellow eye status. Because best-corrected visual acuity does not correspond directly to GA lesion enlargement due to possible foveal sparing, alternative assessments are being explored to capture the relationship between anatomic progression and visual function decline, including microperimetry, low-luminance visual acuity, reading speed assessments, and patient-reported outcomes. Understanding GA progression and its individual variability is critical in the design of clinical studies, in the interpretation and application of clinical trial results, and for counseling patients on how disease progression may affect their individual prognosis.

THE PATHOPHYSIOLOGY OF GEOGRAPHIC ATROPHY SECONDARY TO AGE-RELATED MACULAR DEGENERATION AND THE COMPLEMENT PATHWAY AS A THERAPEUTIC TARGET

Geographic atrophy is an advanced form of age-related macular degeneration that can significantly impact visual function, but has no approved treatment. This review focuses on the pathophysiology of geographic atrophy, particularly the role of complement cascade dysregulation and emerging therapies targeting the complement cascade.

Purpose:

Geographic atrophy (GA) is an advanced, vision-threatening form of age-related macular degeneration (AMD) affecting approximately five million individuals worldwide. To date, there are no approved therapeutics for GA treatment; however, several are in clinical trials. This review focuses on the pathophysiology of GA, particularly the role of complement cascade dysregulation and emerging therapies targeting the complement cascade.

Methods:

Primary literature search on PubMed for GA, complement cascade in age-related macular degeneration. ClinicalTrials.gov was searched for natural history studies in GA and clinical trials of drugs targeting the complement cascade for GA.

Results:

Cumulative damage to the retina by aging, environmental stress, and other factors triggers inflammation via multiple pathways, including the complement cascade. When regulatory components in these pathways are compromised, as with several GA-linked genetic risk factors in the complement cascade, chronic inflammation can ultimately lead to the retinal cell death characteristic of GA. Complement inhibition has been identified as a key candidate for therapeutic intervention, and drugs targeting the complement pathway are currently in clinical trials.

Conclusion:

The complement cascade is a strategic target for GA therapy. Further research, including on natural history and genetics, is crucial to expand the understanding of GA pathophysiology and identify effective therapeutic targets.

Reduction in ocular complement factor B protein in mice and monkeys by systemic administration of factor B antisense oligonucleotide

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of permanent vision loss among the elderly in many industrialized countries, and the complement system plays an important role in the pathogenesis of AMD. Inhibition of complement factor B, a key regulator of the alternative pathway, is implicated as a potential therapeutic intervention for AMD. Here we investigated the effect of liver factor B reduction on systemic and ocular factor B levels.

METHODS

Second-generation antisense oligonucleotides (ASOs) targeting mouse and monkey factor B mRNA were administered by subcutaneous injection to healthy mice or monkeys, and the level of factor B mRNA was assessed in the liver and the eye. In addition, the factor B protein level was determined in plasma and whole eyes from the treated animals.

RESULTS

Mice and monkeys treated with factor B ASOs demonstrated a robust reduction in liver factor B mRNA levels with no change in ocular factor B mRNA levels. Plasma factor B protein levels were significantly reduced in mice and monkeys treated with factor B ASOs, leading to a dramatic reduction in ocular factor B protein, below the assay detection levels.

CONCLUSIONS

The results add to the increasing evidence that the liver is the main source of plasma and ocular factor B protein, and demonstrate that reduction of liver factor B mRNA by an ASO results in a significant reduction in plasma and ocular factor B protein levels. The results suggest that inhibition of liver factor B mRNA by factor B ASOs would reduce systemic alternative complement pathway activation and has potential to be used as a novel therapy for AMD.

GEOGRAPHIC ATROPHY: Semantic Considerations and Literature Review

PURPOSE

There is a lack of agreement regarding the types of lesions and clinical conditions that should be included in the term "geographic atrophy." Varied and conflicting views prevail throughout the literature and are currently used by retinal experts and other health care professionals.

METHODS

We reviewed the nominal definition of the term "geographic atrophy" and conducted a search of the ophthalmologic literature focusing on preceding terminologies and the first citations of the term "geographic atrophy" secondary to age-related macular degeneration.

RESULTS

According to the nominal definition, the term "geography" stands for a detailed description of the surface features of a specific region, indicating its relative position. However, it does not necessarily imply that the borders of the region must be sharply demarcated or related to any anatomical structures. The term "geographical areas of atrophy" was initially cited in the 1960s in the ophthalmologic literature in the context of uveitic eye disease and shortly thereafter also for the description of variants of "senile macular degeneration." However, no direct explanation could be found in the literature as to why the terms "geographical" and "geographic" were chosen. Presumably the terms were used as the atrophic regions resembled the map of a continent or well-defined country borders on thematic geographical maps. With the evolution of the terminology, the commonly used adjunct "of the retinal pigment epithelium" was frequently omitted and solely the term "geographic atrophy" prevailed for the nonexudative late-stage of age-related macular degeneration itself. Along with the quantification of atrophic areas, based on different imaging modalities and the use of both manual and semiautomated approaches, various and inconsistent definitions for the minimal lesion diameter or size of atrophic lesions have also emerged.

CONCLUSION

Reconsideration of the application of the term "geographic atrophy" in the context of age-related macular degeneration seems to be prudent given ongoing advances in multimodal retinal imaging technology with identification of various phenotypic characteristics, and the observation of atrophy development in eyes under antiangiogenic therapy.

Comparing humans and deep learning performance for grading AMD: A study in using universal deep features and transfer learning for automated AMD analysis

BACKGROUND

When left untreated, age-related macular degeneration (AMD) is the leading cause of vision loss in people over fifty in the US. Currently it is estimated that about eight million US individuals have the intermediate stage of AMD that is often asymptomatic with regard to visual deficit. These individuals are at high risk for progressing to the advanced stage where the often treatable choroidal neovascular form of AMD can occur. Careful monitoring to detect the onset and prompt treatment of the neovascular form as well as dietary supplementation can reduce the risk of vision loss from AMD, therefore, preferred practice patterns recommend identifying individuals with the intermediate stage in a timely manner.

METHODS

Past automated retinal image analysis (ARIA) methods applied on fundus imagery have relied on engineered and hand-designed visual features. We instead detail the novel application of a machine learning approach using deep learning for the problem of ARIA and AMD analysis. We use transfer learning and universal features derived from deep convolutional neural networks (DCNN). We address clinically relevant 4-class, 3-class, and 2-class AMD severity classification problems.

RESULTS

Using 5664 color fundus images from the NIH AREDS dataset and DCNN universal features, we obtain values for accuracy for the (4-, 3-, 2-) class classification problem of (79.4%, 81.5%, 93.4%) for machine vs. (75.8%, 85.0%, 95.2%) for physician grading.

DISCUSSION

This study demonstrates the efficacy of machine grading based on deep universal features/transfer learning when applied to ARIA and is a promising step in providing a pre-screener to identify individuals with intermediate AMD and also as a tool that can facilitate identifying such individuals for clinical studies aimed at developing improved therapies. It also demonstrates comparable performance between computer and physician grading.

Evolution of Geographic Atrophy in Participants Treated with Ranibizumab for Neovascular Age-related Macular Degeneration

PURPOSE

To evaluate the risk factors, incidence, and rate of progression of geographic atrophy (GA) in eyes with neovascular age-related macular degeneration (nAMD) treated with ranibizumab.

DESIGN

Post-hoc analysis of a prospective clinical study.

PARTICIPANTS

69 participants with nAMD in at least one eye.

METHODS

Participants were prospectively treated in the study eye with 0.5 mg intravitreal ranibizumab. Study eyes received 4 monthly injections followed by pro re nata injections until a fluid-free macula was achieved on optical coherence tomography. Risk factors assessed included baseline demographics, treatment, and ocular characteristics on imaging. Eyes were evaluated on fundus autofluorescence (FAF) for GA. The rate of GA area growth in study and fellow eyes was analyzed by linear regression of square-root transformed areas.

MAIN OUTCOME MEASURES

Development of new-onset GA and rate of GA area growth measured on ocular imaging, including FAF images of the study eyes.

RESULTS

Sixty-nine participants (mean age 78.8±7.8 years) with an average of 40.0±13.6 months of follow-up were analyzed. Twenty-two of 69 study eyes (32%) were treatment naïve. During their first year of the study, participants received an average of 9.2±3.3 injections in the study eye. Of 63 study eyes with quality baseline images, 22 (35%) had pre-existing GA. Of the remaining 41 eyes, 7 (17%) developed new-onset GA during study follow-up. Those who developed new GA were older (all ≥79 years old) and had received fewer study injections on average (6.9 vs. 10.4 injections at 1 year) compared to those who did not develop new GA. Of the 12 treatment naïve study eyes without GA at baseline, 1 (8.3%) developed new GA during the study. In 21 study eyes with quantifiable GA area, eyes with GA present at baseline (16/21) enlarged by 0.34±0.26 mm/year, compared to 0.19±0.12 mm/year in eyes developing new-onset GA (5/21).

CONCLUSIONS

While 17% of study eyes without GA present at baseline receiving ranibizumab developed new GA, the role of ranibizumab in the development of GA is unclear. Further prospective longitudinal studies are required to determine the eyes most at risk of developing GA in the setting of anti-VEGF treatment.

The Use of Microperimetry to Detect Functional Progression in Non-Neovascular Age-Related Macular Degeneration: A Systematic Review

We reviewed the current literature on the ability of microperimetry to detect non-neovascular age-related macular degeneration (AMD) disease progression. The index test was retinal sensitivity measurement assessed by microperimetry and comparators were other functional measures (best-corrected and low-luminance visual acuities, and fixation stability) and structural parameters [retinal thickness, choroidal thickness, and area of geographic atrophy (GA) determined by color fundus photographs, short-wave or near-infrared fundus autofluorescence]. The reference standard was area of GA. The literature search was conducted in January 2016 and included MEDLINE, EMBASE, the Cochrane Library, Biosis, Science Citation Index, ProQuest Health and Medicine, CINAHL, and Highwire Press. We included 6 studies that enrolled 41 eyes with intermediate AMD (from a single study) and 80 eyes with GA secondary to AMD. Retinal sensitivity measured by microperimetry was the only functional measure that consistently detected progression in each cohort. Insufficient reported data precluded meta-analysis. Various microperimetry parameters were used to assess cohort-level change in retinal sensitivity, but the methods of analysis have yet to mature in complexity in comparison with established glaucoma field progression analysis. Microperimetry-assessed retinal sensitivity measurement may be more sensitive in detecting progression than other functional measures in non-neovascular AMD. However, the lack of standardized testing protocol and methods of progression analysis hindered comparison. Harmonization of testing protocol and development of more robust methods of analyzing raw microperimetric data will facilitate clinical implementation of this valuable retinal assessment tool.

Incidence and Growth of Geographic Atrophy during 5 Years of Comparison of Age-Related Macular Degeneration Treatments Trials

PURPOSE

To estimate the incidence, size, and growth rate of geographic atrophy (GA) during 5 years of follow-up among participants in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

DESIGN

Cohort within a clinical trial.

PARTICIPANTS

Participants included in CATT.

METHODS

A total of 1185 CATT participants were randomly assigned to ranibizumab or bevacizumab treatment and to 3 treatment regimens. Participants were released from protocol treatment at 2 years and examined at approximately 5 years (N = 647). Two masked graders assessed the presence and size of GA in digital color photographs (CPs) and fluorescein angiograms (FAs) taken at baseline and years 1, 2, and 5. Cox proportional hazard models were used to identify risk factors for incidence of GA. Annual change in the square root of the total area of GA was the measure of growth. Multivariate linear mixed models including baseline demographic, treatment, and ocular characteristics on CP/FA and optical coherence tomography (OCT) as candidate risk factors were used to estimate adjusted growth rates, standard errors (SEs), and 95% confidence intervals (CIs).

MAIN OUTCOME MEASURES

Geographic atrophy incidence and growth rate.

RESULTS

Among the 1011 participants who did not have GA at baseline and had follow-up images gradable for GA, the cumulative incidence was 12% at 1 year, 17% at 2 years, and 38% at 5 years. At baseline, older age, hypercholesterolemia, worse visual acuity, larger choroidal neovascularization (CNV) area, retinal angiomatous proliferation (RAP) lesion, GA in the fellow eye, and intraretinal fluid were associated with a higher risk of incident GA. Thicker subretinal tissue complex and presence of subretinal fluid were associated with less GA development. The overall GA growth rate was 0.33 mm/year (SE, 0.02 mm/year). Eyes treated with ranibizumab in the first 2 years of the clinical trial had a higher growth rate than eyes treated with bevacizumab (adjusted growth rate, 0.38 vs. 0.28 mm/year; P = 0.009). Geographic atrophy in the fellow eye, hemorrhage, and absence of sub-retinal pigment epithelium fluid at baseline were associated with a higher growth rate.

CONCLUSIONS

Development of GA is common 5 years after initiating therapy. Several risk factors identified at 2 years of follow-up persist at 5 years of follow-up.

Age-Related Macular Degeneration and Mortality in the Age-Related Eye Disease Study (AREDS): The Effect of Sex and Time

PURPOSE

Age-related macular degeneration (AMD) shares similar risk factors and pathogeneses with cardiovascular diseases (CVDs). Epidemiologic studies over the past 2 decades analyzing the association between AMD and all-cause and CVD-specific mortality have failed to yield conclusive results. The purpose of this analysis is to investigate the sex-specific association between AMD and all-cause and CVD-specific mortality, and to assess whether duration of follow-up alters the strength of association.

DESIGN

The database of Genotypes and Phenotypes (dbGaP) data set for the Age-Related Eye Disease Study, a randomized clinical trial of high-dose antioxidants in AMD prevention, with participants enrolled from 1992 to 1998 and followed through 2005, was used in the analysis.

PARTICIPANTS

There were 4757 Age-Related Eye Disease Study participants aged 55 through 80 years (mean, 69.4 years; 44.1% male) recruited from 11 retinal specialty clinics. Participants had standard Age-Related Eye Disease Study AMD categories (category 1, n = 1117; category 2, n = 1062; category 3, n = 1621; category 4, n = 957).

METHODS

The sex-specific adjusted hazard ratio (HR_adj) between baseline AMD and all-cause and CVD-specific mortality was determined at multiple time points (e.g., 5, 7, 10, and all years), adjusting for age, race, diabetes, hypertension, angina, cancer, smoking, obesity, clinical trial antioxidant treatment category, and education.

MAIN OUTCOME MEASURES

Sex-specific all-cause and CVD-specific mortality.

RESULTS

Mean follow-up was 9.6 years (range, 0.5-12.5 years), with 1087 deaths (category 1, n = 197 [17.6%]; category 2, n = 200 [18.8%]; category 3, n = 356 [22.0%]; category 4, n = 326 [34.1%]). Sex-stratified models demonstrated sex differences; in women, a significant association between AMD category 4 and all-cause mortality existed compared with category 1 at each period (HR_adj, 1.5-2.3; all P ≤ 0.005); similar category 4 findings were present with CVD-specific mortality, strengthening with shorter periods (HR_adj, 1.9-4.6; all P ≤ 0.01). Among men, a significant association between all AMD stages and all-cause (HR_adj, 1.5-2.3; all P ≤ 0.05) and CVD-specific mortality (HR_adj, 1.6-4.0; all P ≤ 0.05) existed for nearly all periods.

CONCLUSIONS

Substantial late AMD cases and deaths exceed those in previous population-based studies to better test mortality-related hypotheses. Age-related macular degeneration was significantly associated with all-cause and CVD-specific mortality. Relationships weakened over a longer duration of follow-up, and sex seems to modify the association. Future analyses are warranted to interrogate the possible clinical usefulness of these relationships.

Tolerability in the elderly population of high-dose alpha lipoic acid: a potential antioxidant therapy for the eye

Purpose

Alpha lipoic acid (ALA) is an antioxidant and iron-chelating supplement that has potential benefits for geographic atrophy in dry age-related macular degeneration as well as other eye diseases. The purpose of this study was to determine the tolerability of ALA in the elderly population.

Patients and methods

Fifteen subjects, age ≥65 years, took sequential ALA doses of 600, 800, and 1,200 mg. Each dose was taken once daily with a meal for 5 days. After each dose was taken by the subjects for 5 days, the subjects were contacted by phone, a review of systems was performed, and they were asked if they thought they could tolerate taking that dose of ALA for an extended period of time.

Results

The 600 mg dose was well tolerated. At the 800 mg dose, one subject had an intolerable flushing sensation. At the 1,200 mg dose, two subjects had intolerable upper gastrointestinal side effects and one subject had an intolerable flushing sensation. Subjects taking gastrointestinal prophylaxis medications had no upper gastrointestinal side effects.

Conclusion

High-dose ALA is not completely tolerated by the elderly. These preliminary data suggest that gastrointestinal prophylaxis may improve tolerability. (ClinicalTrials.gov, NCT02613572).

Evaluation of Geographic Atrophy from Color Photographs and Fundus Autofluorescence Images: Age-Related Eye Disease Study 2 Report Number 11

PURPOSE

To compare measurements of area of geographic atrophy (GA) and change in GA area from color photographs and fundus autofluorescence (FAF) images.

DESIGN

The Age-Related Eye Disease Study 2 (AREDS2) was a prospective multicenter randomized clinical trial evaluating progression of dry age-related macular degeneration (AMD) using color photographs at annual visits over a 5-year study period. The FAF images were acquired in a subset of participants who joined the FAF ancillary study at any of the annual visits over the study period.

PARTICIPANTS

The AREDS2 FAF ancillary study included 8070 corresponding color and FAF visits of 2202 participants with variable follow-up.

METHODS

Corresponding color and FAF images were independently evaluated at a central reading center for GA area measurement, lesion growth, and involvement of the macula center.

MAIN OUTCOME MEASURES

Presence, area, growth rate of GA, and involvement of center of macula from color and FAF images.

RESULTS

Hypoautofluorescence was visible in 2048 visits (25.4%). Agreement for the presence of GA between the 2 modalities had a kappa of 0.79, with 23% of visits with hypoautofluorescence not presenting with GA on color photographs. Percentage agreement for GA presence ranged from 43% at baseline to 81% at year 5 with improving agreement over time. The mean difference in GA area between the 2 modalities was 0.5 mm², with larger areas on FAF. Growth rate of GA was 1.45 mm² from color photographs and 1.43 mm² from FAF images. The center of the macula was involved in 51% of color photographs and 56% with FAF images.

CONCLUSIONS

Geographic atrophy may be detected earlier by the use of FAF images, but over the course of the study, the 2 modalities become comparable. Progression of GA area is comparable between color photographs and FAF images, but evaluating involvement of the center of the macula may differ, probably because of macular pigmentation blocking autofluorescence.

VISUAL FUNCTION MEASURES IN EARLY AND INTERMEDIATE AGE-RELATED MACULAR DEGENERATION

PURPOSE

The objectives of this study were to evaluate 1) the feasibility of performing computerized tests of low luminance visual acuity (LLVA), cone-specific contrast (Cone Contrast Test [CCT]), contrast sensitivity, and microperimetry and 2) the test-retest repeatability of these outcomes in dry age-related macular degeneration (AMD).

METHODS

This prospective study enrolled 30 subjects at a single site (8 controls, 8 early AMD, and 12 intermediate AMD). Subjects underwent LLVA, contrast sensitivity, CCT, and microperimetry with eye tracking. Low luminance deficit was defined as best-corrected visual acuity minus LLVA in EDTRS letters. Follow-up testing was administered at approximately 1 month.

RESULTS

There was high test-retest repeatability at one month for all visual function metrics (intraclass correlations >0.7) except log contrast sensitivity (intraclass correlations 0.6). Compared with controls, patients with intermediate AMD showed significant deficits on best-corrected visual acuity, LLVA, low luminance deficit, percent-reduced threshold on microperimetry, and red CCT (P < 0.05), but not on contrast sensitivity, green and blue CCT.

CONCLUSION

This pilot study supports the feasibility and reliability of using LLVA, microperimetry, and CCT in early dry AMD. Our data suggest these measures can be used as alternative future clinical trial endpoints. A larger, prospective natural history study of alternative visual function measures in dry AMD is warranted.

Modeling Visual Acuity in Geographic Atrophy Secondary to Age-Related Macular Degeneration

Purpose: To analyze and model visual acuity (VA) in geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Methods: The course of VA was analyzed using Turnbull's estimator in 226 eyes with uni- or bilateral GA due to AMD (151 patients; mean age 74.0 ± 7.6 years; mean follow-up time 33.4 ± 23.4 months) from the natural history FAM (Fundus-Autofluorescence Imaging in AMD) study. The variables ‘age at baseline', ‘gender', ‘lesion size', ‘diagnosis of the fellow eye', ‘status of the fovea', ‘focality of the lesion' and ‘pattern' were evaluated for effects on predicting VA using linear mixed-effects models. Results: Mean VA at baseline was 0.6 (Snellen 20/80) ± 0.4 logMAR [range -0.1 to 1.8 (20/17 to hand motions)], showing an estimated mean increase of 0.181 (95% CI 0.152-0.210) and 0.256 (0.214-0.300) after 2 and 4 years of follow-up, respectively. The percentage of eyes with a loss of ≥3 lines was 34% by 2 years and 47% by 4 years. Linear mixed model analysis suggested that 65% of VA variability could be explained by the assessed predictor variables. The strongest effect was found for the ‘status of the fovea' (0.69 logMAR units between ‘definitively spared fovea' and ‘definitive foveal involvement', p < 0.001). The second strongest effect was identified for ‘total lesion size' (effects between 0.02 and 0.09 logMAR units for each mm depending on foveal involvement, p < 0.001, square root transformed values). Conclusions: These findings underscore the importance of GA lesion characteristics as these have the strongest impact on VA. Natural history data and modeling VA to other variables will be helpful for refining outcome parameters and estimating possible benefits of therapeutic interventions.

Geographic Atrophy and Choroidal Neovascularization in the Same Eye: A Review

Geographic atrophy (GA) and choroidal neovascularization (CNV), the two late forms of age-related macular degeneration, are generally considered two distinct entities. However, GA and CNV can occur simultaneously in the same eye, with GA usually occurring first. The prevalence of this combined entity is higher in histological studies than in clinical studies. No distinct systemic or genetic risk characteristics are associated with the combined GA/CNV entity, although on clinical examination and retinal imaging it can feature drusen or subretinal drusenoid deposits. GA and CNV may exist within the spectrum of a single disease, or they may be two very different diseases. Therapy with antivascular endothelial growth factor (anti-VEGF) is often successful for CNV, but some evidence suggests increased rates of GA development in eyes treated with anti-VEGF. In this article, we review the current literature regarding the epidemiology, clinical presentation, and treatment options for patients with the combined GA/CNV entity.

Automated geographic atrophy segmentation for SD-OCT images using region-based C-V model via local similarity factor

Age-related macular degeneration (AMD) is the leading cause of blindness among elderly individuals. Geographic atrophy (GA) is a phenotypic manifestation of the advanced stages of non-exudative AMD. Determination of GA extent in SD-OCT scans allows the quantification of GA-related features, such as radius or area, which could be of important value to monitor AMD progression and possibly identify regions of future GA involvement. The purpose of this work is to develop an automated algorithm to segment GA regions in SD-OCT images. An en face GA fundus image is generated by averaging the axial intensity within an automatically detected sub-volume of the three dimensional SD-OCT data, where an initial coarse GA region is estimated by an iterative threshold segmentation method and an intensity profile set, and subsequently refined by a region-based Chan-Vese model with a local similarity factor. Two image data sets, consisting on 55 SD-OCT scans from twelve eyes in eight patients with GA and 56 SD-OCT scans from 56 eyes in 56 patients with GA, respectively, were utilized to quantitatively evaluate the automated segmentation algorithm. We compared results obtained by the proposed algorithm, manual segmentation by graders, a previously proposed method, and experimental commercial software. When compared to a manually determined gold standard, our algorithm presented a mean overlap ratio (OR) of 81.86% and 70% for the first and second data sets, respectively, while the previously proposed method OR was 72.60% and 65.88% for the first and second data sets, respectively, and the experimental commercial software OR was 62.40% for the second data set.

Prospective Trial of Treat-and-Extend versus Monthly Dosing for Neovascular Age-Related Macular Degeneration: TREX-AMD 1-Year Results

PURPOSE

To assess prospectively a treat-and-extend (TREX) management strategy compared with monthly dosing of intravitreal ranibizumab in treatment-naïve neovascular age-related macular degeneration (AMD) patients.

DESIGN

Phase IIIb, multicenter, randomized, controlled clinical trial.

PARTICIPANTS

Sixty patients with treatment-naïve neovascular AMD randomized 1:2 to monthly or TREX management.

METHODS

Patients with Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA) from 20/32 to 20/500 (Snellen equivalent) were randomized to receive intravitreal 0.5 mg ranibizumab monthly or according to a TREX protocol. The TREX patients were treated monthly for at least 3 doses, until resolution of clinical and spectral-domain optical coherence tomography evidence of exudative disease activity; the interval between visits then was individualized according to a strict prospective protocol.

MAIN OUTCOME MEASURES

Mean ETDRS BCVA change from baseline.

RESULTS

At baseline, mean age was 77 years (range, 59-96 years), mean BCVA was 20/60 (Snellen equivalent), and mean central retinal thickness (CRT) was 511 μm. Fifty-seven eyes (95%) completed month 12, at which point mean BCVA improved by 9.2 and 10.5 letters in the monthly and TREX cohorts, respectively (P = 0.60). The mean number of injections administered through month 12 was 13.0 and 10.1 (range, 7-13) in the monthly and TREX cohorts, respectively (P < 0.0001). Among TREX patients, 7 (18%) were maximally extended, 4 (10%) demonstrated fluid at every visit, and at month 12, 18 (45%) had achieved an extension interval of 8 weeks or more; the mean maximum extension interval between injections after the first 3 monthly doses was 8.4 weeks (range, 4-12 weeks). Most TREX patients who demonstrated recurrent exudative disease activity (17/24 [71%]) were unable to extend beyond their initial maximum extension interval.

CONCLUSIONS

The TREX neovascular AMD management strategy used in this prospective, randomized, controlled trial resulted in visual and anatomic gains comparable with those obtained with monthly dosing.

Geographic atrophy in patients with advanced dry age-related macular degeneration: current challenges and future prospects

Geographic atrophy (GA) of the retinal pigment epithelium (RPE) is a devastating complication of age-related macular degeneration (AMD). GA may be classified as drusen-related (drusen-associated GA) or neovascularization-related (neovascular-associated GA). Drusen-related GA remains a large public health concern due to the burden of blindness it produces, but pathophysiology of the condition is obscure and there are no proven treatment options. Genotyping, cell biology, and clinical imaging point to upregulation of parainflammatory pathways, oxidative stress, and choroidal sclerosis as contributors, among other factors. Onset and monitoring of progression is accomplished through clinical imaging instrumentation such as optical coherence tomography, photography, and autofluorescence, which are the tools most helpful in determining end points for clinical trials at present. A number of treatment approaches with diverse targets are in development at this time, some of which are in human clinical trials. Neovascular-associated GA is a consequence of RPE loss after development of neovascular AMD. The neovascular process leads to a plethora of cellular stresses such as ischemia, inflammation, and dramatic changes in cell environment that further taxes RPE cells already dysfunctional from drusen-associated changes. GA may therefore develop secondary to the neovascular process de novo or preexisting drusen-associated GA may continue to worsen with the development of neovascular AMD. Neovascular-associated GA is a prominent cause of continued vision loss in patients with otherwise successfully treated neovascular AMD. Clearly, treatment with vascular endothelial growth factor (VEGF) inhibitors early in the course of the neovascular disease is of great clinical benefit. However, there is a rationale and some suggestive evidence that anti-VEGF agents themselves could be toxic to RPE and enhance neovascular-associated GA. The increasing prevalence of legal blindness from this condition due to the aging of the general population lends urgency to the search for a therapy to ameliorate GA.

Current therapeutic developments in atrophic age-related macular degeneration

Age-related macular degeneration (AMD), a degenerative disorder of the central retina, is the leading cause of irreversible blindness in the elderly. The underlying mechanism of the advanced form of dry AMD, also named geographic atrophy (GA) or atrophic AMD, remains unclear. Consequently, no cure is available for dry AMD or GA. The only prevention option currently available is the Age-Related Eye Disease Study (AREDS) formulation, which has been demonstrated to slow down the progression of dry AMD. This review summarises recent advances in therapy for dry AMD and GA. Building on the new understanding of the disease and recent technological breakthroughs, numerous ongoing clinical trials have the goal of meeting the need to cure AMD. Therapeutic agents are being developed to target the key features of the disease, including inhibiting the complement pathway and other inflammatory pathways, reducing oxidative stress and protecting retinal pigment epithelial (RPE) cells, inhibiting lipofuscin and visual cycle, regenerating RPE cells from stem cells and restoring choroidal blood flow. Some of these therapeutic options, especially the stem cell-based therapy, hold great promise, which brings great hope for this devastating blinding disease.

Phase ii, randomized, placebo-controlled, 90-day study of emixustat hydrochloride in geographic atrophy associated with dry age-related macular degeneration

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Prognostic implications of imaging in atrophic macular degeneration and its use in clinical practice and clinical trial design

Clinical prognostic markers in atrophic age-related macular degeneration include the extent of existing atrophy, fundus autofluorescence (FAF) patterns and optical coherence tomography changes in the outer retina/retinal pigment epithelium interface. The prognostic implications of these findings may be used to determine not just the rate of disease progression but also influence the likelihood, magnitude and clinical relevance of therapy responses. FAF phenotypes have been extensively investigated; however, the pathophysiological mechanisms behind their appearance have not been fully elucidated. Optical coherence tomography imaging is additive to FAF imaging in atrophic age-related macular degeneration, allowing the visualization of detail not available through FAF imaging whilst also displaying subtle changes correlating with the FAF phenotypes themselves, thereby giving clues to their histological determinates. The developing understanding of these imaging modalities and consequent development of prognostically useful classification systems have widespread implication in clinical care and clinical trial design.

Population Pharmacokinetics and Pharmacodynamics of Lampalizumab Administered Intravitreally to Patients With Geographic Atrophy

Intravitreally administered lampalizumab is an investigational complement inhibitor directed against complement factor D (CFD) for the treatment of geographic atrophy (GA) secondary to age-related macular degeneration. We sought to develop an integrated ocular and systemic pharmacokinetic/pharmacodynamic model for lampalizumab in patients with GA using the data from the clinical phase I and II studies. The kinetics of lampalizumab and CFD disposition were well described by the combined ocular/serum target-mediated drug disposition model using a quasi-steady-state approximation. This model takes into account the drug, target, and drug-target complex clearance, their transfer rates between ocular and serum compartments, and turnover kinetics of CFD. The constructed model provided a prediction of target occupancy in ocular tissues and supported that the two dosing regimens (10 mg q4w and 10 mg q6w) selected for the phase III studies are expected to be efficacious and able to achieve near-complete target engagement in the vitreous humor.

Increased Fundus Autofluorescence and Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration: The GAIN Study

PURPOSE

To define the role of increased fundus autofluorescence (FAF), a surrogate for lipofuscin content, as a risk factor for progression of geographic atrophy (GA).

DESIGN

Prospective natural history cohort study, the GAIN (Characterization of geographic atrophy progression in patients with age-related macular degeneration).

METHODS

setting: Single-center study conducted in Barcelona, Spain.

PATIENTS

After screening of 211 patients, 109 eyes of 82 patients with GA secondary to age-related macular degeneration and a minimum follow-up of 6 months were included.

OBSERVATION PROCEDURES

Lipofuscin content was classified independently by 2 masked observers according to FAF patterns described previously. Bivariate, stratified, and multivariable analyses were used to explore the associations between GA growth and independent variables. Mediation analysis was used to evaluate the contribution of FAF patterns to GA progression.

MAIN OUTCOME

Progression of GA in mm(2)/year as measured with FAF.

RESULTS

Median follow-up was 18 months (range, 6-42). Median GA growth was 1.61 mm(2)/year. FAF, baseline area of atrophy, and time of follow-up were independently associated with GA progression (P < .004). FAF patterns and baseline area of atrophy were strongly associated (P < .0001), suggesting potential confounding. Mediation analysis suggested that most of the effect of FAF patterns on GA growth was actually caused by baseline area of atrophy.

CONCLUSIONS

FAF patterns, baseline area of atrophy, and time of follow-up were associated with GA progression. However, FAF patterns seem to be a consequence (not a cause) of enlarging atrophy and their effect on GA progression seems mostly driven by baseline area of atrophy.

Automated segmentation of geographic atrophy of the retinal epithelium via random forests in AREDS color fundus images

BACKGROUND

Age-related macular degeneration (AMD), left untreated, is the leading cause of vision loss in people older than 55. Severe central vision loss occurs in the advanced stage of the disease, characterized by either the in growth of choroidal neovascularization (CNV), termed the "wet" form, or by geographic atrophy (GA) of the retinal pigment epithelium (RPE) involving the center of the macula, termed the "dry" form. Tracking the change in GA area over time is important since it allows for the characterization of the effectiveness of GA treatments. Tracking GA evolution can be achieved by physicians performing manual delineation of GA area on retinal fundus images. However, manual GA delineation is time-consuming and subject to inter-and intra-observer variability.

METHODS

We have developed a fully automated GA segmentation algorithm in color fundus images that uses a supervised machine learning approach employing a random forest classifier. This algorithm is developed and tested using a dataset of images from the NIH-sponsored Age Related Eye Disease Study (AREDS). GA segmentation output was compared against a manual delineation by a retina specialist.

RESULTS

Using 143 color fundus images from 55 different patient eyes, our algorithm achieved PPV of 0.82±0.19, and NPV of 0:95±0.07.

DISCUSSION

This is the first study, to our knowledge, applying machine learning methods to GA segmentation on color fundus images and using AREDS imagery for testing. These preliminary results show promising evidence that machine learning methods may have utility in automated characterization of GA from color fundus images.

Potential role of lampalizumab for treatment of geographic atrophy

The purpose of this article is to review the pathways underlying age-related macular degeneration and potential therapeutic targets, focusing on the complement pathway and the recent MAHALO Phase II trial of the investigational drug lampalizumab. This trial was the first to have shown positive results for the treatment of geographic atrophy in age-related macular degeneration. It has potential as a future treatment, and is currently undergoing a Phase III trial.

Clinical and genetic factors associated with progression of geographic atrophy lesions in age-related macular degeneration

Worldwide, age-related macular degeneration (AMD) is a serious threat to vision loss in individuals over 50 years of age with a pooled prevalence of approximately 9%. For 2020, the number of people afflicted with this condition is estimated to reach 200 million. While AMD lesions presenting as geographic atrophy (GA) show high inter-individual variability, only little is known about prognostic factors. Here, we aimed to elucidate the contribution of clinical, demographic and genetic factors on GA progression. Analyzing the currently largest dataset on GA lesion growth (N = 388), our findings suggest a significant and independent contribution of three factors on GA lesion growth including at least two genetic factors (ARMS2_rs10490924 [P < 0.00088] and C3_rs2230199 [P < 0.00015]) as well as one clinical component (presence of GA in the fellow eye [P < 0.00023]). These correlations jointly explain up to 7.2% of the observed inter-individual variance in GA lesion progression and should be considered in strategy planning of interventional clinical trials aimed at evaluating novel treatment options in advanced GA due to AMD.

Directional Kinetics of Geographic Atrophy Progression in Age-Related Macular Degeneration with Foveal Sparing

PURPOSE

To describe the directional kinetics of the spread of geographic atrophy (GA) spread in eyes with age-related macular degeneration and foveal sparing.

DESIGN

Prospective, noninterventional natural history study: Fundus Autofluorescence Imaging in Age-Related Macular Degeneration (FAM; clinicaltrials.gov identifier, NCT00393692).

SUBJECTS

Participants of the FAM study exhibiting foveal sparing of GA.

METHODS

Eyes were examined longitudinally with fundus autofluorescence (FAF; excitation wavelength, 488 nm; emission wavelength, >500 nm) and near infrared (NIR) reflectance imaging (Spectralis HRA+OCT or HRA2; Heidelberg Engineering, Heidelberg, Germany). Areas of foveal sparing and GA were measured by 2 independent readers using a semiautomated software tool that allows for combined NIR reflectance and FAF image grading (RegionFinder; Heidelberg Engineering). A linear mixed effect model was used to model GA kinetics over time.

MAIN OUTCOME MEASURE

Change of GA lesion size over time (central vs. peripheral progression).

RESULTS

A total of 47 eyes of 36 patients (mean age, 73.8±7.5 years) met the inclusion criteria. Mean follow-up time was 25.2±16.9 months (range, 5.9-74.6 months). Interreader agreement for measurements of GA and foveal-sparing size were 0.995 and 0.946, respectively. Mean area progression of GA toward the periphery was 2.27±0.22 mm(2)/year and 0.25±0.03 mm(2)/year toward the center. Analysis of square root-transformed data revealed a 2.8-fold faster atrophy progression toward the periphery than toward the fovea. Faster atrophy progression toward the fovea correlated with faster progression toward the periphery in presence of marked interindividual differences.

CONCLUSIONS

The results demonstrate a significantly faster centrifugal than centripetal GA spread in eyes with GA and foveal sparing. Although the underlying pathomechanisms for differential GA progression remain unknown, local factors may be operative that protect the foveal retina-retinal pigment epithelial complex. Quantification of directional spread characteristics and modeling may be useful in the design of interventional clinical trials aiming to prolong foveal survival in eyes with GA.

Macular atrophy progression and 7-year vision outcomes in subjects from the ANCHOR, MARINA, and HORIZON studies: the SEVEN-UP study

PURPOSE

To assess the incidence and progression of macular atrophy and other key anatomic outcomes over 7 to 8 years in an early cohort of ranibizumab-treated exudative age-related macular degeneration patients.

DESIGN

Follow-up analysis of long-term outcomes in a multicenter treatment cohort.

METHODS

Fourteen study sites enrolled 65 previous subjects from the ranibizumab treatment arms of the ANCHOR, MARINA, and HORIZON trials. In a single update visit, clinical assessment and retinal imaging studies were performed, with comparison with each subject's prior results from the previous trials. Early Treatment Diabetic Retinopathy Study visual acuity was the primary outcome. Secondary outcomes, including area of macular atrophy and selected anatomic factors, were analyzed for associations with long-term vision outcomes.

RESULTS

At a mean 7.3 years after ANCHOR or MARINA enrollment, mean visual acuity was 54 letters, study eyes having received a mean 1.6 injections per year since the HORIZON study. Macular atrophy was present in 98% of study eyes, the mean area increasing from 0.83 ± 0.96 mm(2) at the ANCHOR or MARINA year 2 exit to 2.22 ± 1.6 mm(2) at the SEVEN-UP visit, a growth rate of 0.28 mm(2)/year. Progression of macular atrophy was associated significantly with visual decline over this 5-year period (P < .001), and final macular atrophy lesion size was related significantly to final vision (P < .001). Other key anatomic outcomes (macular thickening, thinning, or fluid and submacular fibrosis) did not have significant effects on vision outcomes.

CONCLUSIONS

Seven years after initiation of intensive ranibizumab therapy for exudative age-related macular degeneration, macular atrophy progression and severity were the primary anatomic determinants of visual outcomes.

Growth of geographic atrophy in the comparison of age-related macular degeneration treatments trials

PURPOSE

To evaluate the growth of geographic atrophy (GA) during anti-vascular endothelial growth factor (VEGF) therapy.

DESIGN

Cohort within a clinical trial.

PARTICIPANTS

Patients included in the Comparison of Age-related Macular Degeneration Treatments Trials (CATT).

METHODS

Participants were randomly assigned to injections of ranibizumab or bevacizumab and to a 2-year dosing regimen of monthly or pro re nata (PRN) or to monthly for 1 year and PRN the following year. Digital color photographs and fluorescein angiograms at baseline and 1 and 2 years were evaluated for GA, and the total area of GA was measured by 2 graders masked to treatment; differences were adjudicated. Multivariate linear mixed models of the annual change in the square root of the area included baseline demographic, treatment, and ocular characteristics on imaging as candidate risk factors.

MAIN OUTCOME MEASURES

Geographic atrophy growth rate.

RESULTS

Among 1185 participants, 86 (7.3%) had GA at baseline, 120 (10.1%) developed GA during year 1, and 36 (3.0%) developed GA during year 2. Among 194 eyes evaluable for growth, the rate was 0.43 mm/yr (standard error [SE], ±0.03 mm/year). In multivariate analysis, the growth rate was 0.37 mm/year in eyes receiving bevacizumab and 0.49 mm/year in eyes receiving ranibizumab (difference, 0.11 mm/yr; 95% confidence interval [CI], 0.01-0.22; P = 0.03). Growth rate did not differ between eyes treated monthly and PRN (P = 0.85). Eyes with subfoveal choroidal neovascularization (CNV) lesions had a lower growth rate than eyes with nonsubfoveal CNV lesions (difference, 0.12; 95% CI, 0.01-0.22; P = 0.03). Eyes with GA farther from the fovea had higher growth rates by 0.14 (95% CI, 0.01-27) mm/year for every millimeter farther from the fovea. The growth rate was 0.58 mm/year for eyes with predominantly classic lesions, 0.41 mm/year for eyes with minimally classic lesions, and 0.30 mm/year for eyes with occult only lesions (P < 0.01). The growth rate in eyes having a fellow eye with GA was higher by 0.13 mm/year (95% CI, 0.01-0.24; P = 0.03) than in eyes without GA in the fellow eye. Eyes with epiretinal membrane had a higher growth rate than eyes without epiretinal membrane (difference, 0.16; 95% CI, 0.03-0.30; P = 0.02).

CONCLUSIONS

Geographic atrophy growth depends on several ocular factors. Ranibizumab may accelerate GA growth.

Complement activation and choriocapillaris loss in early AMD: implications for pathophysiology and therapy

Age-related macular degeneration (AMD) is a common and devastating disease that can result in severe visual dysfunction. Over the last decade, great progress has been made in identifying genetic variants that contribute to AMD, many of which lie in genes involved in the complement cascade. In this review we discuss the significance of complement activation in AMD, particularly with respect to the formation of the membrane attack complex in the aging choriocapillaris. We review the clinical, histological and biochemical data that indicate that vascular loss in the choroid occurs very early in the pathogenesis of AMD, and discuss the potential impact of vascular dropout on the retinal pigment epithelium, Bruch's membrane and the photoreceptor cells. Finally, we present a hypothesis for the pathogenesis of early AMD and consider the implications of this model on the development of new therapies.

Nutritional Supplements for Age-Related Macular Degeneration

The Age-Related Eye Disease Study (AREDS) and The Age-Related Eye Disease Study 2 (AREDS2), are the only large-scale, long-term, randomized controlled trials to demonstrate a role of nutritional supplements in reducing risk of progression to advanced forms of age-related macular degeneration (AMD). This review summarizes the study design, main results, and implications of these trials in the clinical care of nonexudative AMD patients. In addition, it discusses other recent prospective studies focusing on efficacy of nutritional supplementation for prevention or slowing progression of AMD as well as briefly discusses possible effect of genotypes on response to AREDS supplementation.

Vision-threatening lesions developing with longer-term follow-up after treatment of neovascular age-related macular degeneration

PURPOSE

To assess the development of vision-threatening lesions at least 3.5 years after initiating anti-vascular endothelial growth factor (VEGF) for choroidal neovascularization (CNV) in eyes with age-related macular degeneration (AMD).

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 75 patients (81 eyes) with CNV secondary to AMD who received intravitreous anti-VEGF treatment and were followed for at least 3.5 years after initiating treatment.

METHODS

Retrospective record review of patients initiating anti-VEGF treatment between November 2005 and June 2008 at a university-based institution for whom at least 3.5 years of follow-up was available at the same institution.

MAIN OUTCOME MEASURES

Predominantly hemorrhagic lesions or geographic atrophy (GA).

RESULTS

Among 75 patients (81 eyes; 59% were women; median age, 78 years), mean follow-up was 4.9 years and at least 6 years for 40%. Median visual acuity (VA) was 20/80 (interquartile range [IQR], 20/50-20/100) initially, 20/63 (IQR, 20/40-20/160) at 2 years, 20/80 (IQR, 20/40-20/200) at 3.5 years, and 20/63 (IQR 20/32-20/200) at 6 years. Six eyes (7%) had predominantly hemorrhagic lesions initially, whereas this developed in an additional 3 eyes (4%, 95% confidence interval [CI], 1% to 10%) in 3.5 years and in 1 additional eye (1%, 95% CI, 0.03% to 7%) at more than 3.5 years of follow-up. Initially, GA within or overlapping the boundary of the entire CNV was present in 4 eyes (5%) and outside this boundary in 8 eyes (10%). Geographic atrophy enlarged in each eye over time. The only eyes that developed GA outside the CNV boundary were those that had GA outside the lesion at baseline. Additional atrophy within the boundary of CNV defined at baseline, termed "atrophic disciform scars," developed in 5 eyes (6%), all within 4 years of treatment initiation.

CONCLUSIONS

Longer-term follow-up of neovascular AMD managed with anti-VEGF therapy suggests that predominantly hemorrhagic lesions may develop within 3.5 years of initiating therapy and more than 3.5 years after initiating therapy. In contrast, new areas of GA beyond the boundaries of the CNV lesion as defined at initiation of anti-VEGF therapy seem unlikely to develop if there is no GA outside of the CNV lesion initially.

Optical Coherence Tomography Monitoring Strategies for A-VEGF-Treated Age-Related Macular Degeneration: An Evidence-Based Analysis

BACKGROUND

New anti-angiogenesis pharmacotherapies have dramatically altered treatment of age-related macular degeneration (AMD), the leading cause of blindness in older adults. Monthly intraocular injections however, are extremely burdensome to ophthalmologists, patients, and their families. Repeated injections also increase risks of complications or adverse events. Although the pharmacokinetics of anti-vascular endothelial growth factor (A-VEGF) drugs are fairly well known, an individuals' AMD presentation and their pharmacodynamics or response to the drug has been shown to be extremely variable. Therefore treating everyone on the same fixed or standard regimen has potential for undertreating or overtreating patients, and drug costs are not trivial.

OBJECTIVES

To review monitoring strategies and to evaluate the role of optical coherence tomography (OCT) in guiding management of A-VEGF-treated neovascular AMD (n-AMD) patients.

DATA SOURCES

Systematic reviews of biographic databases for studies published between 2008 and February 2013 involving A-VEGF-treated n-AMD patients monitored in longitudinal follow-up.

REVIEW METHODS

Studies were grouped according to varying treatments, monitoring schedules, and re-treatment protocols reported for n-AMD patients treated with A-VEGF. Several outcomes were evaluated across strategies including visual acuity (VA), retinal anatomy, re-treatment criteria and frequencies of clinical follow-up, OCT imaging investigations, and intravitreal injections. Results were summarized qualitatively, as heterogeneity in study objectives and methods precluded formal meta-analysis.

RESULTS

A systematic review identified 18 randomized controlled trials (RCTs) and 20 observational studies involving A-VEGF treatment employing various monitoring and as-needed (PRN) re-treatment protocols. Several maintenance strategies were unsuccessful, resulting in lower VA gains and stabilization than monthly injections in A-VEGF-treated n-AMD. These included fixed quarterly treatment; fixed quarterly monitoring and PRN re-treatment; and monthly monitoring with either VA-guided re-treatment or quantitative-only VA/OCT- (central retinal thickness [CRT] > 100 μm) guided re-treatment. PRN re-treatment strategies with A-VEGF on the basis of monthly follow-up and rigorous reviews of OCT qualitative and quantitative measures of disease activity did decrease injection burden while maintaining visual gains. Gains in VA obtained with PRN re-treatment in usual clinical practice, however, were not as high as gains in clinical trials.

CONCLUSIONS

To reduce treatment burden and provide a more individualized treatment strategy for n-AMD patients, OCT/VA-guided PRN treatment strategies have become the preferred and the dominant maintenance strategy. Success of these strategies, however, is dependent on close monitoring and adherence to tightly defined re-treatment criteria.

A phase ia dose-escalation study of the anti-factor D monoclonal antibody fragment FCFD4514S in patients with geographic atrophy

PURPOSE

Multicenter, open-label, single-dose, dose-escalation Phase Ia study to determine the safety, tolerability, maximum tolerated dose, and immunogenicity of FCFD4514S, an antigen-binding fragment from a humanized monoclonal antibody directed against complement factor D, in patients with geographic atrophy.

METHODS

Eighteen patients with geographic atrophy (lesion size: ≥ 0.75 disk areas; best-corrected visual acuity: 20/125-20/400 Snellen equivalent) were sequentially enrolled and received 1 of 6 escalating doses of intravitreal FCFD4514S subject to dose-limiting toxicity criteria. Follow-up assessments (clinical examination, best-corrected visual acuity, intraocular pressure) were conducted at postadministration Days 1, 3, 7, 14, 30, 60, and 90. Serum pharmacokinetics, immunogenicity, and complement activity were also evaluated.

RESULTS

All patients completed the study with no reported FCFD4514S-related dose-limiting toxicities or ocular or systemic adverse events. The maximum tolerated dose for this study was 10 mg, the highest dose tested. No antitherapeutic antibody response or adverse effects on systemic complement activity were observed. Time to maximum serum concentration was 1 day to 3 days postdosing; serum terminal half-life was 5.9 days.

CONCLUSION

Single-dose intravitreal FCFD4514S administrations were safe and well tolerated and not associated with any study drug-related ocular or systemic adverse events. These data support a multidose safety and tolerability assessment of FCFD4514S in geographic atrophy.

Geographic atrophy progression in eyes with age-related macular degeneration: role of fundus autofluorescence patterns, fellow eye and baseline atrophy area

BACKGROUND/OBJECTIVE

To evaluate if fundus autofluorescence (FAF) patterns around geographic atrophy (GA) and the status of the fellow eye have an impact on GA progression.

METHODS

We included 54 eyes of 35 patients with GA. Areas of GA were quantified by RegionFinder software.

RESULTS

GA progression rates in eyes with a diffuse trickling pattern (median 1.42 mm(2)/year) were significantly higher than in normal eyes (median 0.22 mm(2)/year) and eyes with other diffuse FAF patterns (median 0.46 mm(2)/year). Eyes with a banded pattern had a significantly higher progression rate (median 0.81 mm(2)/year) than those without any FAF abnormalities (p = 0.038). The group with baseline total atrophy of the eyes <1 disk area (DA; median 0.42 mm(2)) had an inverse relation with GA progression compared to the groups with baseline atrophy >1 DA (p < 0.05).

CONCLUSION

Diffuse trickling and banded patterns may have an impact on GA progression and may serve as prognostic factors.

Drusen measurements comparison by fundus photograph manual delineation versus optical coherence tomography retinal pigment epithelial segmentation automated analysis

PURPOSE

To compare drusen measurements obtained from color fundus and infrared retromode photographs with those derived from spectral-domain optical coherence tomography.

METHODS

Drusen lesions identified on the planar (color and infrared) imaging modalities were manually segmented by two independent graders using previously described reading center software to produce quantitative measurements of drusen area and number. The corresponding volume Cirrus OCT datasets were analyzed using commercial retinal pigment epithelium analysis algorithms to segment the retinal pigment epithelium band and estimated the drusen area. Drusen numbers were extracted from retinal pigment epithelium elevation maps. Intraclass correlation coefficients assessed agreement between graders; graders' average measurements were compared with optical coherence tomography (OCT) using paired T-tests.

RESULTS

Excellent agreement between graders was observed (r = 0.951-0.974). No statistical difference was found in the area values obtained by color (0.85 ± 0.26 mm(2), P = 0.43) or retromode (1.15 ± 0.32 mm(2), P = 0.35) compared with those obtained by OCT (0.98 ± 0.28 mm). The number of drusen identified by OCT (13.15 ± 3.19) was significantly lower than that determined by manual segmentation of color (53.7 ± 13.18) and retromode (100.13 ± 16.18) images.

CONCLUSION

Although the number of drusen individualized by commercial OCT algorithms is significantly lower than by planar fundus imaging modalities, the OCT-measured drusen area is not affected, suggesting that the algorithm counts confluent drusen as a single drusen.