Progression of Unifocal versus Multifocal Geographic Atrophy in Age-Related Macular Degeneration: A Systematic Review and Meta-analysis

Deep Learning-Based Prediction of Individual Geographic Atrophy Progression from a Single Baseline OCT

Objective

To identify the individual progression of geographic atrophy (GA) lesions from baseline OCT images of patients in routine clinical care.

Design

Clinical evaluation of a deep learning-based algorithm.

Subjects

One hundred eighty-four eyes of 100 consecutively enrolled patients.

Methods

OCT and fundus autofluorescence (FAF) images (both Spectralis, Heidelberg Engineering) of patients with GA secondary to age-related macular degeneration in routine clinical care were used for model validation. Fundus autofluorescence images were annotated manually by delineating the GA area by certified readers of the Vienna Reading Center. The annotated FAF images were anatomically registered in an automated manner to the corresponding OCT scans, resulting in 2-dimensional en face OCT annotations, which were taken as a reference for the model performance. A deep learning-based method for modeling the GA lesion growth over time from a single baseline OCT was evaluated. In addition, the ability of the algorithm to identify fast progressors for the top 10%, 15%, and 20% of GA growth rates was analyzed.

Main Outcome Measures

Dice similarity coefficient (DSC) and mean absolute error (MAE) between manual and predicted GA growth.

Results

The deep learning-based tool was able to reliably identify disease activity in GA using a standard OCT image taken at a single baseline time point. The mean DSC for the total GA region increased for the first 2 years of prediction (0.80-0.82). With increasing time intervals beyond 3 years, the DSC decreased slightly to a mean of 0.70. The MAE was low over the first year and with advancing time slowly increased, with mean values ranging from 0.25 mm to 0.69 mm for the total GA region prediction. The model achieved an area under the curve of 0.81, 0.79, and 0.77 for the identification of the top 10%, 15%, and 20% growth rates, respectively.

Conclusions

The proposed algorithm is capable of fully automated GA lesion growth prediction from a single baseline OCT in a time-continuous fashion in the form of en face maps. The results are a promising step toward clinical decision support tools for therapeutic dosing and guidance of patient management because the first treatment for GA has recently become available.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Geographic Atrophy Natural History Versus Treatment: Time to Fovea

BACKGROUND AND OBJECTIVE

The Food and Drug Administration recently approved treatments of geographic atrophy (GA). Our study aims to quantify the time for a lesion to reach the central fovea based on reduction of GA growth rates from therapeutics compared to the natural history.

PATIENTS AND METHODS

A previously published study calculates local border expansion rate of GA lesions at varying retinal eccentricities. In this study, we use these rates to model GA expansion toward the fovea and the effects of treatments that reduce growth in GA area by 15% to 45% on lesions of varying sizes with posterior margin 250, 500, 750, 1000, 1250, 1500, and 3000 µm from the fovea.

RESULTS

Lesions with an area 8 mm2 and posterior edge 500 µm from the fovea will reach the fovea in 5.08 years with no treatment, but the same lesions will reach the fovea in 5.85, 6.52, 7.36, and 8.46 years with a treatment that reduces growth in GA area by 15%, 25%, 35%, and 45%, respectively.

CONCLUSIONS

Distance of the posterior edge of the lesion was the primary factor in GA growth toward the fovea, and lesion size only minimally affects growth rates of GA. Based on the efficacy of current and future therapeutics and distance of GA to the fovea, our study provides the marginal time benefit of treatment to guide patients and clinicians, placing both the natural history of GA and the effects of current and future treatments into clinical context. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

METformin for the MINimization of Geographic Atrophy Progression (METforMIN): A Randomized Trial

Purpose

Metformin use has been associated with a decreased risk of age-related macular degeneration (AMD) progression in observational studies. We aimed to evaluate the efficacy of oral metformin for slowing geographic atrophy (GA) progression.

Design

Parallel-group, multicenter, randomized phase II clinical trial.

Participants

Participants aged ≥ 55 years without diabetes who had GA from atrophic AMD in ≥ 1 eye.

Methods

We enrolled participants across 12 clinical centers and randomized participants in a 1:1 ratio to receive oral metformin (2000 mg daily) or observation for 18 months. Fundus autofluorescence imaging was obtained at baseline and every 6 months.

Main Outcome Measures

The primary efficacy endpoint was the annualized enlargement rate of the square root-transformed GA area. Secondary endpoints included best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) at each visit.

Results

Of 66 enrolled participants, 34 (57 eyes) were randomized to the observation group and 32 (53 eyes) were randomized to the treatment group. The median follow-up duration was 13.9 and 12.6 months in the observation and metformin groups, respectively. The mean ± standard error annualized enlargement rate of square root transformed GA area was 0.35 ± 0.04 mm/year in the observation group and 0.42 ± 0.04 mm/year in the treatment group (risk difference = 0.07 mm/year, 95% confidence interval = -0.05 to 0.18 mm/year; P = 0.26). The mean ± standard error decline in BCVA was 4.8 ± 1.7 letters/year in the observation group and 3.4 ± 1.1 letters/year in the treatment group (P = 0.56). The mean ± standard error decline in LLVA was 7.3 ± 2.5 letters/year in the observation group and 0.8 ± 2.2 letters/year in the treatment group (P = 0.06). Fourteen participants in the metformin group experienced nonserious adverse events related to metformin, with gastrointestinal side effects as the most common. No serious adverse events were attributed to metformin.

Conclusions

The results of this trial as conducted do not support oral metformin having effects on reducing the progression of GA. Additional placebo-controlled trials are needed to explore the role of metformin for AMD, especially for earlier stages of the disease.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Classification and Growth Rate of Chorioretinal Atrophy after Voretigene Neparvovec-Rzyl for RPE65-Mediated Retinal Degeneration

PURPOSE

Classify the appearance and quantify the growth rate of chorioretinal atrophy in patients who received voretigene neparvovec-rzyl (VN) for RPE65-mediated retinal degeneration.

DESIGN

Multicenter retrospective analysis.

SUBJECTS

Patients who underwent subretinal VN injection at 5 institutions and demonstrated posterior-pole chorioretinal atrophy.

METHODS

Ultrawidefield scanning laser ophthalmoscopy or color fundus photos were assessed before and after subretinal VN. Atrophy was defined as regions with ≥ 2 of the following: (1) partial or complete retinal pigment epithelial depigmentation; (2) round shape; (3) sharp margins; and (4) increased visibility of choroidal vessels. Atrophy was qualitatively classified into different subtypes. All atrophy was manually segmented. Linear mixed-effects models with random slopes and intercepts were fit using atrophy area and square root of atrophy area.

MAIN OUTCOME MEASURES

Number of eyes with each atrophy pattern, and slopes of linear mixed-effects models.

RESULTS

Twenty-seven eyes from 14 patients across 5 centers developed chorioretinal atrophy after subretinal VN. A mean of 5.8 ± 2.7 images per eye obtained over 2.2 ± 0.8 years were reviewed, and atrophy was categorized into touchdown (14 eyes), nummular (15 eyes), and perifoveal (12 eyes) subtypes. Fifteen eyes demonstrated > 1 type of atrophy. Thirteen of 14 patients demonstrated bilateral atrophy. The slopes of the mixed-effects models of atrophy area and square root of atrophy area (estimate ± standard error) were 1.7 ± 1.3 mm2/year and 0.6 ± 0.2 mm/year for touchdown atrophy, 5.5 ± 1.3 mm2/year and 1.2 ± 0.2 mm/year for nummular atrophy, and 16.7 ± 1.8 mm2/year and 2.3 ± 0.2 mm/year for perifoveal atrophy. The slopes for each type of atrophy were significantly different in the square root of atrophy model, which best fit the data (P < 0.05).

CONCLUSIONS

Chorioretinal atrophy after subretinal VN for RPE65-mediated retinal degeneration developed according to a touchdown, nummular, and/or perifoveal pattern. Perifoveal atrophy grew the most rapidly, while touchdown atrophy grew the least rapidly. Understanding the causes of these findings, which are present in a minority of patients, merits further investigation.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Treating patients with geographic atrophy: are we there yet?

Geographic atrophy (GA) is a progressive degenerative disease that significantly contributes to visual impairment in individuals aged 50 years and older. The development of GA is influenced by various modifiable and non-modifiable risk factors, including age, smoking, and specific genetic variants, particularly those related to the complement system regulators. Given the multifactorial and complex nature of GA, several treatment approaches have been explored, such as complement inhibition, gene therapy, and cell therapy. The recent approval by the Food and Drug Administration of pegcetacoplan, a complement C3 inhibitor, marks a significant breakthrough as the first approved treatment for GA. Furthermore, numerous interventions are currently in phase II or III trials, alongside this groundbreaking development. In light of these advancements, this review provides a comprehensive overview of GA, encompassing risk factors, prevalence, genetic associations, and imaging characteristics. Additionally, it delves into the current landscape of GA treatment, emphasizing the latest progress and future considerations. The goal of starting this discussion is to ultimately identify the most suitable candidates for each therapy, highlight the importance of tailoring treatments to individual cases, and continue monitoring the long-term implications of these emerging interventions.

Progression Dynamics of Early versus Later Stage Atrophic Lesions in Nonneovascular Age-Related Macular Degeneration Using Quantitative OCT Biomarker Segmentation

PURPOSE

To investigate the progression of geographic atrophy secondary to nonneovascular age-related macular degeneration in early and later stage lesions using artificial intelligence-based precision tools.

DESIGN

Retrospective analysis of an observational cohort study.

SUBJECTS

Seventy-four eyes of 49 patients with ≥ 1 complete retinal pigment epithelial and outer retinal atrophy (cRORA) lesion secondary to age-related macular degeneration were included. Patients were divided between recently developed cRORA and lesions with advanced disease status.

METHODS

Patients were prospectively imaged by spectral-domain OCT volume scans. The study period encompassed 18 months with scheduled visits every 6 months. Growth rates of recent cRORA-converted lesions were compared with lesions in an advanced disease status using mixed effect models.

MAIN OUTCOME MEASURES

The progression of retinal pigment epithelial loss (RPEL) was considered the primary end point. Secondary end points consisted of external limiting membrane disruption and ellipsoid zone loss. These pathognomonic imaging biomarkers were quantified using validated deep-learning algorithms. Further, the ellipsoid zone/RPEL ratio was analyzed in both study cohorts.

RESULTS

Mean (95% confidence interval [CI]) square root progression of recently converted lesions was 79.68 (95% CI, -77.14 to 236.49), 68.22 (95% CI, -101.21 to 237.65), and 84.825 (95% CI, -124.82 to 294.47) mm/half year for RPEL, external limiting membrane loss, and ellipsoid zone loss respectively. Mean square root progression of advanced lesions was 131.74 (95% CI, -22.57 to 286.05), 129.96 (95% CI, -36.67 to 296.59), and 116.84 (95% CI, -90.56 to 324.3) mm/half year for RPEL, external limiting membrane loss, and ellipsoid zone loss, respectively. RPEL (P = 0.038) and external limiting membrane disruption (P = 0.026) progression showed significant differences between the 2 study cohorts. Further recent converters had significantly (P < 0.001) higher ellipsoid zone/RPEL ratios at all time points compared with patients in an advanced disease status (1.71 95% CI, 1.12-2.28 vs. 1.14; 95% CI, 0.56-1.71).

CONCLUSION

Early cRORA lesions have slower growth rates in comparison to atrophic lesions in advanced disease stages. Differences in growth dynamics may play a crucial role in understanding the pathophysiology of nonneovascular age-related macular degeneration and for the interpretation of clinical trials in geographic atrophy. Individual disease monitoring using artificial intelligence-based quantification paves the way toward optimized geographic atrophy management.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Associations of systemic health and medication use with the enlargement rate of geographic atrophy in age-related macular degeneration

BACKGROUND

The associations of geographic atrophy (GA) progression with systemic health status and medication use are unclear.

METHODS

We manually delineated GA in 318 eyes in the Age-Related Eye Disease Study. We calculated GA perimeter-adjusted growth rate as the ratio between GA area growth rate and mean GA perimeter between the first and last visit for each eye (mean follow-up=5.3 years). Patients' history of systemic health and medications was collected through questionnaires administered at study enrolment. We evaluated the associations between GA perimeter-adjusted growth rate and 27 systemic health factors using univariable and multivariable linear mixed-effects regression models.

RESULTS

In the univariable model, GA perimeter-adjusted growth rate was associated with GA in the fellow eye at any visit (p=0.002), hypertension history (p=0.03), cholesterol-lowering medication use (p<0.001), beta-blocker use (p=0.02), diuretic use (p<0.001) and thyroid hormone use (p=0.03). Among the six factors, GA in the fellow eye at any visit (p=0.008), cholesterol-lowering medication use (p=0.002), and diuretic use (p<0.001) were independently associated with higher GA perimeter-adjusted growth rate in the multivariable model. GA perimeter-adjusted growth rate was 51.1% higher in patients with versus without cholesterol-lowering medication use history and was 37.8% higher in patients with versus without diuretic use history.

CONCLUSIONS

GA growth rate may be associated with the fellow eye status, cholesterol-lowering medication use, and diuretic use. These possible associations do not infer causal relationships, and future prospective studies are required to investigate the relationships further.

Perspectives from clinical trials: is geographic atrophy one disease?

Geographic atrophy (GA) is currently an untreatable condition. Emerging evidence from recent clinical trials show that anti-complement therapy may be a successful treatment option. However, several trials in this therapy area have failed as well. This raises several questions. Firstly, does complement therapy work for all patients with GA? Secondly, is GA one disease? Can we assume that these failed clinical trials are due to ineffective interventions or are they due to flawed clinical trial designs, heterogeneity in GA progression rates or differences in study cohorts? In this article we try to answer these questions by providing an overview of the challenges of designing and interpreting outcomes of randomised controlled trials (RCTs) in GA. These include differing inclusion-exclusion criteria, heterogeneous progression rates of the disease, outcome choices and confounders.

Future perspectives for treating patients with geographic atrophy

Purpose

Geographic atrophy (GA) is a late-stage form of age-related macular degeneration (AMD) characterized by the expansion of atrophic lesions in the outer retina. There are currently no approved pharmacological treatments to prevent or slow the progression of GA. This review describes the progression and assessment of GA, predictive imaging features, and complement-targeting investigational drugs for GA.

Methods

A literature search on GA was conducted.

Results

Expansion of atrophic lesions in patients with GA is associated with a decline in several measures of visual function. GA lesion size has been moderately associated with measures obtained through microperimetry, whereas GA lesion size in the 1-mm diameter area centered on the fovea has been associated with visual acuity. Optical coherence tomography (OCT) can provide 3-dimensional quantitative assessment of atrophy and is useful for identifying early atrophy in GA. Features that have been found to predict the development of GA include certain drusen characteristics and pigmentary abnormalities. Specific OCT features, including hyper-reflective foci and OCT-reflective drusen substructures, have been associated with AMD disease progression. Lesion characteristics, including focality, regularity of shape, location, and perilesional fundus autofluorescence patterns, have been identified as predictors of faster GA lesion growth. Certain investigational complement-targeting drugs have shown efficacy in slowing the progression of GA.

Conclusion

GA is a progressive disease associated with irreversible vision loss. Therefore, the lack of treatment options presents a significant unmet need. OCT and drugs under investigation for GA are promising future tools for disease management.

A hierarchical Bayesian entry time realignment method to study the long-term natural history of diseases

A major question in clinical science is how to study the natural course of a chronic disease from inception to end, which is challenging because it is impractical to follow patients over decades. Here, we developed BETR (Bayesian entry time realignment), a hierarchical Bayesian method for investigating the long-term natural history of diseases using data from patients followed over short durations. A simulation study shows that BETR outperforms an existing method that ignores patient-level variation in progression rates. BETR, when combined with a common Bayesian model comparison tool, can identify the correct disease progression function nearly 100% of the time, with high accuracy in estimating the individual disease durations and progression rates. Application of BETR in patients with geographic atrophy, a disease with a known natural history model, shows that it can identify the correct disease progression model. Applying BETR in patients with Huntington's disease demonstrates that the progression of motor symptoms follows a second order function over approximately 20 years.

Progression of cRORA (Complete RPE and Outer Retinal Atrophy) in Dry Age-Related Macular Degeneration Measured Using SD-OCT

Purpose

The purpose of this study was to evaluate the long-term rate of progression and baseline predictors of geographic atrophy (GA) using complete retinal pigment epithelium and outer retinal atrophy (cRORA) annotation criteria.

Methods

This is a retrospective study. Columns of GA were manually annotated by two graders using a self-developed software on optical coherence tomography (OCT) B-scans and projected onto the infrared images. The primary outcomes were: (1) rate of area progression, (2) rate of square root area progression, and (3) rate of radial progression towards the fovea. The effects of 11 additional baseline predictors on the primary outcomes were analyzed: total area, focality (defined as the number of lesions whose area is >0.05 mm2), circularity, total lesion perimeter, minimum diameter, maximum diameter, minimum distance from the center, sex, age, presence/absence of hypertension, and lens status.

Results

GA was annotated in 33 pairs of baseline and follow-up OCT scans from 33 eyes of 18 patients with dry age-related macular degeneration (AMD) followed for at least 6 months. The mean rate of area progression was 1.49 ± 0.86 mm2/year (P < 0.0001 vs. baseline), and the mean rate of square root area progression was 0.33 ± 0.15 mm/year (P < 0.0001 vs. baseline). The mean rate of radial progression toward the fovea was 0.07 ± 0.11 mm/year. A multiple variable linear regression model (adjusted r2 = 0.522) revealed that baseline focality and female sex were significantly correlated with the rate of GA area progression.

Conclusions

GA area progression was quantified using OCT as an alternative to conventional measurements performed on fundus autofluorescence images. Baseline focality correlated with GA area progression rate and lesion's minimal distance from the center correlated with GA radial progression rate toward the center. These may be important markers for the assessment of GA activity.

Translational Relevance

Advanced method linking specific retinal micro-anatomy to GA area progression analysis.

Dry age-related macular degeneration in the Japanese population

PURPOSE

To elucidate the clinical characteristics of eyes with dry age-related macular degeneration (AMD) in Japan.

STUDY DESIGN

Retrospective.

METHODS

We performed a nationwide survey of dry AMD. A questionnaire on dry AMD was sent to 3,801 major hospitals and eye clinics nationwide. Whenever both eyes met the diagnostic criteria, only the eye with more advanced geographic atrophy was included.

RESULTS

In the current survey, 81 patients (81 eyes) with dry AMD were included. Of the 81 patients, 56 (69.1%) were men, and the mean age of the patients was 76.6 ± 8.4 (range, 54-94) years. Twenty-four patients (29.6%) had a history of smoking. The decimal best corrected-visual acuity (BCVA) was equal to or better than 0.7 in 25 eyes (30.9%), but worse than 0.1 in 17 eyes (21.0%). The mean BCVA was 0.62 ± 0.59 in logarithm of the minimum angle of resolution. Lesion size (the greatest linear dimension of the largest geographic atrophy) was ≥ 2 disc diameter in 33 eyes (40.7%) and < 1 disc diameter in 21 eyes (25.9%). Soft drusen was observed in 27 eyes (33.3%), and reticular pseudodrusen was observed in 31 eyes (38.3%). Of the 81 patients, the other eye was diagnosed as dry AMD in 26 eyes (32.1%), neovascular AMD in 16 eyes (19.8%), and intermediate AMD in 18 eyes (22.2%).

CONCLUSION

Dry AMD in the Japanese population has characteristics of male predominance, older age, high prevalence of reticular pseudodrusen, and high bilaterality.

Local Progression Kinetics of Geographic Atrophy Depends Upon the Border Location

Purpose

To assess the influence of lesion morphology and location on geographic atrophy (GA) growth rate.

Methods

We manually delineated GA on color fundus photographs of 237 eyes in the Age-Related Eye Disease Study. We calculated local border expansion rate (BER) as the linear distance that a point on the GA border traveled over 1 year based on a Euclidean distance map. Eye-specific BER was defined as the mean local BER of all points on the GA border in an eye. The percentage area affected by GA was defined as the GA area divided by the total retinal area in the region.

Results

GA enlarged 1.51 ± 1.96 mm2 in area and 0.13 ± 0.11 mm in distance over 1 year. The GA area growth rate (mm2/y) was associated with the baseline GA area (P < 0.001), perimeter (P < 0.001), lesion number (P < 0.001), and circularity index (P < 0.001); in contrast, eye-specific BER (mm/y) was not significantly associated with any of these factors. As the retinal eccentricity increased from 0 to 3.5 mm, the local BER increased from 0.10 to 0.24 mm/y (P < 0.001); in contrast, the percentage of area affected by GA decreased from 49.3% to 2.3%.

Conclusions

Using distance-based measurements allows GA progression evaluation without significant confounding effects from baseline GA morphology. Local GA progression rates increased as a function of retinal eccentricity within the macula which is opposite of the trend for GA distribution, suggesting that GA initiation and enlargement may be mediated by different biological processes.

Geographic atrophy severity and mortality in age-related macular degeneration

PURPOSE

To examine the association between geographic atrophy (GA) disease characteristics and mortality risk.

METHODS

We manually delineated color fundus photographs of 209 Age-Related Eye Disease Study (AREDS) participants with GA secondary to age-related macular degeneration to identify total area of atrophy, GA effective radius growth rate, disease laterality, and the presence of foveal center involvement. Associations between GA characteristics and mortality were assessed with Cox proportional hazards models adjusted for health status indicators.

RESULTS

During a median follow-up of 6.8 years, 48 (23.0%) participants with GA died. In adjusted models, accounting for age, sex, and health status, participants with total GA area in the highest quartile had a significantly increased risk of all-cause mortality compared to those with total GA area in the lowest quartile (hazard ratio [HR], 3.42; 95% confidence interval [CI], 1.32-8.86; P = 0.011). GA effective radius growth rate, bilateral disease, and the presence of foveal center involvement were not significantly associated with mortality. In a multivariable model, including health status indicators and all GA characteristics, total area of atrophy in the highest quartile remained significantly associated with mortality (HR, 4.65; 95% CI, 1.29-16.70; P = 0.019).

CONCLUSIONS

More extensive GA, as indicated by a greater total area of atrophy, was associated with an increased risk of all-cause mortality in our cohort. The extent of GA may reflect the extent of underlying disease processes that contribute to greater mortality risk, further suggesting that GA may be part of a systemic rather than purely ocular disease process.

Natural history of central sparing in geographic atrophy secondary to non-exudative age-related macular degeneration

BACKGROUND

The macular central 1 mm diameter zone is crucial to patients' visual acuity, but the long-term natural history of central sparing in eyes with geographic atrophy (GA) is unknown.

METHODS

We manually segmented GA in 210 eyes with GA involving central 1 mm diameter zone (mean follow-up=3.8 years) in the Age-Related Eye Disease Study. We measured the residual area in central 1 mm diameter zone and calculated central residual effective radius (CRER) as square root of (residual area/π). A linear mixed-effects model was used to model residual size over time. We added a horizontal translation factor to each data set to account for different durations of GA involving the central zone.

RESULTS

The decline rate of central residual area was associated with baseline residual area (p=0.008), but a transformation from central residual area to CRER eliminated this relationship (p=0.51). After the introduction of horizontal translation factors to each data set, CRER declined linearly over approximately 13 years (r²=0.80). The growth rate of total GA effective radius was 0.14 mm/year (95% CI 0.12 to 0.15), 3.7-fold higher than the decline rate of CRER (0.038 mm/year, 95% CI 0.034 to 0.042). The decline rate of CRER was 53.3% higher in eyes with than without advanced age-related macular degeneration in the fellow eyes at any visit (p=0.007).

CONCLUSIONS

CRER in eyes with GA declined linearly over approximately 13 years and may serve as an anatomic endpoint in future clinical trials aiming to preserve the central zone.

Geographic Atrophy Growth Is Strongly Related to Lesion Perimeter: Unifying Effects of Lesion Area, Number, and Circularity on Growth

PURPOSE

To investigate the underlying reason for the previously observed impact of baseline lesion size, number, and circularity on geographic atrophy (GA) growth rate.

DESIGN

Retrospective analysis of a multicenter, prospective, randomized controlled trial.

PARTICIPANTS

Age-Related Eye Disease Study participants with GA secondary to nonexudative age-related macular degeneration.

METHODS

We manually delineated atrophic lesions on color fundus photographs of 318 eyes with GA followed up over at least 2 visits (mean follow-up duration, 5.1 ± 3.0 years). We calculated GA area growth rate for each eye based on the first and last visit. GA perimeter-adjusted growth rate was defined as the ratio between GA area growth rate and mean GA perimeter between the first and last visit for each eye.

MAIN OUTCOME MEASURES

GA area growth rate, growth rate of the square root of GA area, and GA perimeter-adjusted growth rate.

RESULTS

GA area growth rate was correlated strongly with mean GA perimeter (r² = 0.66). GA area growth rate was associated with baseline GA area (r² = 0.39; P < 0.001), lesion number (r² = 0.10; P < 0.001), and circularity index (r² = 0.28; P < 0.001). The use of the square root of GA area reduced the influence of baseline GA area (but not lesion number or circularity) on GA growth rate. In comparison, GA perimeter-adjusted growth rate (0.098 ± 0.062 mm/year) was not correlated with baseline GA area (r² = 0.005; P = 0.20), lesion number (r² = 0.00009; P = 0.86), or circularity index (r² = 0.007; P = 0.14). GA perimeter-adjusted growth rate was 50.0% higher in eyes whose fellow eyes showed GA at any visit (0.102 ± 0.062 mm/year) than in eyes whose fellow eyes never demonstrated GA during follow-up (0.068 ± 0.049 mm/year).

CONCLUSIONS

The growth rate of GA area is associated strongly with lesion perimeter. This relationship explains the previously observed influences of baseline GA size, lesion number, and circularity on GA growth rate. GA perimeter-adjusted growth rate is uncorrelated with the 3 morphologic factors and may serve as a surrogate outcome measure to monitor GA progression in future studies.

Relationship of Topographic Distribution of Geographic Atrophy to Visual Acuity in Nonexudative Age-Related Macular Degeneration

PURPOSE

To investigate the topographic distribution of geographic atrophy (GA) and to identify an anatomic endpoint that correlates with visual acuity (VA) in eyes with GA.

DESIGN

Retrospective analysis of a multicenter, prospective, randomized controlled trial.

PARTICIPANTS

The Age-Related Eye Disease Study participants with GA secondary to nonexudative age-related macular degeneration.

METHODS

We manually delineated GA on 1654 fundus photographs of 365 eyes. We measured GA areas in 9 subfields on the Early Treatment Diabetic Retinopathy Study (ETDRS) grid and correlated them with VA via a mixed-effects model. We determined the optimal diameter for the central zone by varying the diameter from 0 to 10 mm until the highest r² between GA area in the central zone and VA was achieved. We estimated the VA decline rate over 8 years using a linear mixed model.

MAIN OUTCOME MEASURES

Geographic atrophy area in macular subfields and VA.

RESULTS

The percentage of area affected by GA declined as a function of retinal eccentricity. GA area was higher in the temporal than the nasal region (1.30 ± 1.75 mm² vs. 1.10 ± 1.62 mm²; P = 0.005) and in the superior than the inferior region (1.26 ± 1.73 mm² vs. 1.03 ± 1.53 mm²; P < 0.001). Total GA area correlated poorly with VA (r² = 0.07). Among GA areas in 9 subfields, only GA area in the central zone was associated independently with VA (P < 0.001). We determined 1 mm as the optimal diameter for the central zone in which GA area correlated best with VA (r² = 0.45). On average, full GA coverage of the central 1-mm diameter zone corresponded to 34.8 letters' decline in VA. The VA decline rate was comparable between eyes with initial noncentral and central GA before GA covered the entire central 1-mm diameter zone (2.7 letters/year vs. 2.8 letters/year; P = 0.94).

CONCLUSIONS

The prevalence of GA varies significantly across different macular regions. Although total GA area was associated poorly with VA, GA area in the central 1-mm diameter zone was correlated significantly with VA and may serve as a surrogate endpoint in clinical trials.

Long-term natural history of visual acuity in eyes with choroideremia: a systematic review and meta-analysis of data from 1004 individual eyes

BACKGROUND/AIMS

Best-corrected visual acuity (BCVA) is the most common primary endpoint in treatment trials for choroideremia (CHM) but the long-term natural history of BCVA is unclear.

METHODS

We searched in seven databases to identify studies that reported BCVA of untreated eyes with CHM. We sought individual-level data and performed segmented regression between BCVA and age. For eyes followed longitudinally, we introduced a horizontal translation factor to each dataset to account for different ages at onset of a rapid BCVA decline.

RESULTS

We included 1004 eyes from 23 studies. BCVA of the right and left eyes was moderately correlated (r=0.60). BCVA as a function of age followed a 2-phase decline (slow followed by rapid decline), with an estimated transition age of 39.1 years (95% CI 33.5 to 44.7). After the introduction of horizontal translation factors to longitudinal datasets, BCVA followed a 2-phase decline until it reached 0 letters (r²=0.90). The BCVA decline rate was 0.33 letters/year (95% CI -0.38 to 1.05) before 39 years, and 1.23 letters/year (95% CI 0.55 to 1.92) after 39 years (p=0.004).

CONCLUSION

BCVA in eyes with CHM follows a 2-phase linear decline with a transition age of approximately 39 years. Future trials enrolling young patients may not be able to use BCVA as a primary or sole endpoint, but rather, may need to employ additional disease biomarkers that change before age 39. BCVA may still have utility as a primary endpoint for patients older than 39 years who have measurable BCVA decline rates.

Long-term Natural History of Atrophy in Eyes with Choroideremia-A Systematic Review and Meta-analysis of Individual-Level Data

PURPOSE

To conduct a systematic review and meta-analysis of the natural history of atrophy secondary to choroideremia (CHM).

CLINICAL RELEVANCE

A sensitive and reliable anatomic measure to monitor disease progression is needed in treatment trials for CHM. However, the long-term natural history of the residual retinal pigment epithelium (RPE) is unclear, with reported RPE area decline rates varying widely among patients.

METHODS

We searched in 7 literature databases up through July 17, 2019, to identify studies that assessed the residual RPE area in untreated eyes with CHM using fundus autofluorescence (FAF). We sought individual-eye data and investigated the RPE decline pattern using 3 models: the area linear model (ALM), radius linear model (RLM), and area exponential model (AEM), in which the area, radius, and log-transformed area of RPE change linearly with time, respectively. To account for different eyes' entry times into the studies, we added a horizontal translation factor to each dataset. The RPE decline rate was estimated using a 2-stage random-effects meta-analysis. We assessed the risk of bias using the Quality In Prognosis Studies tool.

RESULTS

Of 807 articles screened, we included 9 articles containing cross-sectional data (257 eyes) from 6 studies and longitudinal data (229 visits from 68 eyes) from 5 studies. The residual RPE area followed a trend of exponential decay as a function of patient age. After the introduction of horizontal translation factors to longitudinal datasets of individual eyes, the datasets fit along a straight line in the AEM over nearly 60 years (r² = 0.997). The decline rate of log-transformed RPE area was 0.050 (95% confidence interval, 0.046-0.055) log(mm²)/year and was independent of the baseline RPE area (r = -0.18; P = 0.15) and age (r = 0.06; P = 0.63). In contrast, the decline rates of the area and effective radius of residual RPE strongly correlated with the baseline RPE area (r = 0.90 and 0.61, respectively; P < 0.001).

CONCLUSIONS

The loss of residual RPE area in untreated eyes with CHM follows the AEM over approximately 60 years. Log-transformed residual RPE area measured by FAF can serve as an anatomic endpoint to monitor CHM.