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

Geographic atrophy in Asia

PURPOSE

Geographic atrophy (GA) is a late-stage manifestation of age-related macular degeneration associated with vision loss. Differences between Asian and non-Asian populations with GA have been reported. It is essential to understand these differences because they may reflect variations in the natural history of the disease and its underlying pathophysiology, impacting resultant future treatment strategies and clinical trial designs.

METHODS

A non-systematic search for articles published up to November 22, 2023 was performed using PubMed. Reference lists from included articles were reviewed and relevant articles manually selected and included, as well as read for background information about the topic. Only articles in English were considered for inclusion in this narrative review.

RESULTS

Although the overall prevalence of GA appears to be low across Asia and shows a male predominance, regional variability is evident. Compared with White and other non-Asian populations, Asian populations typically have more distinct but fewer drusen overall (regardless of type), smaller GA lesion size at presentation, a thicker choroid, and lower rates of bilaterality. In both Asian and non-Asian populations, certain characteristics of GA may be associated with an increased risk of fast disease progression.

CONCLUSION

The characteristics of GA in Asian populations show some similarities as well as relevant differences compared with those in White and other non-Asian populations. A better understanding of the characteristics associated with GA subphenotypes and predictors of progression will help to optimize management strategies for Asian patients with GA and improve study designs for future interventional trials.

Prevalence and risk factors of undiagnosed age-related macular degeneration: the Korea National Health and Nutrition Examination Survey 2017-2020

This study aimed to evaluate the prevalence and risk factors for undiagnosed age-related macular degeneration (AMD) in the Korean population. This cross-sectional study utilized data from the Korea National Health and Nutrition Examination Survey (KNHANES 2017-2020), which included a total of 13,737 subjects of 40 years or older. Cases in which AMD was identified through imaging interpretation of the KNHANES data, but the patients had not received a prior medical diagnosis of AMD, were classified as undiagnosed AMD. The prevalence and risk factors for undiagnosed AMD were analyzed. Among the patients identified to having AMD through KNHANES, the prevalence of undiagnosed AMD was 95.25% (95% confidence interval [CI], 94.13-96.37). Multivariate analysis revealed that a low level of education was significantly associated with a higher risk of undiagnosed AMD (p = 0.0066). A low level of education was also linked to a higher risk of undiagnosed early AMD (p = 0.0369) and neovascular AMD (p = 0.0399). Aging was strongly associated with an increased risk of undiagnosed geographic atrophy (p < 0.0001). Physical activity was associated with a lower risk of undiagnosed neovascular AMD (p = 0.0107). The high prevalence of undiagnosed AMD in the Korean population highlights the need for regular fundus examinations to facilitate accurate detection of AMD. Low education level emerged as a significant risk factor for undiagnosed AMD, emphasizing the importance of targeted interventions for this population to reduce the risk of visual impairment due to AMD.

Relationships Between Diet and Geographic Atrophy Progression in the Age-Related Eye Diseases Studies 1 and 2

Background/Objectives: The objective of this study was to analyze the relationships between diet and geographic atrophy (GA) progression, both area-based and proximity-based, for dietary pattern, components, and micronutrients. Methods: In the Age-Related Eye Diseases Study (AREDS) and AREDS2, an Alternative Mediterranean Diet Index (aMedi), its nine components, and individual micronutrient intakes were calculated. Mixed-model regression was performed for square root GA area, GA foveal proximity, and acuity. Results: The study populations comprised 657 (AREDS) and 1179 eyes (AREDS2). For area-based progression, a higher aMedi was associated with slower progression in AREDS2 and (in analyses excluding MUFA:SFA) AREDS. A higher intake was associated with slower progression for seven components (including vegetables and fruit at Bonferroni) and four components (including fruit and less red meat at Bonferroni), and seven and 15 nutrients, in AREDS1/2, respectively. For proximity-based progression, a higher aMedi was associated with slower progression in AREDS. A higher intake was associated with slower progression for three components (including vegetables at Bonferroni) and two components, and 10 and 8 nutrients, in AREDS1/2, respectively. With increasing oral supplementation, associations between proximity-based progression and aMedi/components/nutrients were weaker. In AREDS2 eyes with non-central GA, higher aMedi was associated with a slower acuity decline. Conclusions: A Mediterranean-type diet is associated with slower GA area-based progression and slower progression to the fovea, accompanied by a slower decline in acuity. The most important components and micronutrients for incidence, area-based progression, and foveal progression overlap only partially. For the latter two, they include vegetables, fruit, and less red meat. These findings suggest the benefits of targeted nutritional and supplementation strategies.

Determinants of Four-Year Visual Acuity Loss in Geographic Atrophy: An Analysis of Age-Related Eye Disease Study and Age-Related Eye Disease Study 2

PURPOSE

To investigate the relationship between geographic atrophy (GA) progression and change in best-corrected visual acuity (BCVA) over 4 years and identify factors associated with faster BCVA loss.

DESIGN

Secondary analysis of 2 randomized controlled clinical trials.

PARTICIPANTS

Age-Related Eye Disease Study (AREDS) and AREDS2 participants with GA secondary to nonexudative age-related macular degeneration.

METHODS

Baseline and annual color fundus photographs were assessed for GA area and proximity to the foveal center. Best-corrected visual acuity was measured using Early Treatment Diabetic Retinopathy Study logarithm of the minimum angle of resolution (logMAR) charts. Analyses included BCVA change over 4 years, with the relationship of BCVA decline with GA progression and other baseline factors examined using multivariable linear mixed-effects models.

MAIN OUTCOME MEASURES

The primary outcome was BCVA change over 4 years. Secondary outcomes included BCVA change from baseline to years 1, 2, and 3.

RESULTS

We included 1351 eyes from 994 participants, including 594 eyes from 464 participants with 4-year BCVA follow-up. Higher baseline BCVA, smaller baseline GA proximity to the foveal center, and greater GA growth rate were each independently associated with larger BCVA loss over 4 years (each P < 0.001). Among the 594 eyes with 4-year BCVA data, 69 eyes with a baseline BCVA < 40 letters (Snellen equivalent of 20/160 or worse) and 42 eyes with baseline GA located more than 1 mm from the foveal center did not experience significant BCVA loss over 4 years. In contrast, 483 eyes that met both criteria of baseline BCVA ≥ 40 letters and GA lesions involving or within 1 mm of the foveal center showed significant BCVA loss over 4 years (mean change = -11.33 letters [95% confidence interval = -12.80 to -9.84]), with faster GA progression associated with larger BCVA loss (P < 0.001).

CONCLUSIONS

In this cohort, eyes with GA involving or within 1 mm of the foveal center and a baseline BCVA of ≥ 40 letters appeared more likely to experience significant BCVA loss, suggesting these eyes may benefit more from therapies that slow GA progression. Our findings support a personalized approach to managing patients with GA, potentially guiding the design of future GA trials.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Fundus Autofluorescence Variation in Geographic Atrophy of Age-Related Macular Degeneration: A Clinicopathologic Correlation

Purpose

The purpose of this study was to develop ground-truth histology about contributors to variable fundus autofluorescence (FAF) signal and thus inform patient selection for treating geographic atrophy (GA) in age-related macular degeneration (AMD).

Methods

One woman with bilateral multifocal GA, foveal sparing, and thick choroids underwent 535 to 580 nm excitation FAF in 6 clinic visits (11 to 6 years before death). The left eye was preserved 5 hours after death. Eye-tracked ex vivo imaging aligned sub-micrometer epoxy resin sections (n = 140, 60 µm apart) with clinic data. Light microscopic morphology corresponding to FAF features assessed included drusen-driven atrophy, persistent hyperautofluorescence (hyperFAF) islands and peninsulas within atrophy, and hyperFAF and hypoautofluorescence (hypoFAF) inner junctional zone (IJZ) and outer junctional zone (OJZ) relative to descent of external limiting membrane (ELM). Atrophy growth rate was calculated.

Results

HypoFAF atrophic spots appeared in association with drusen, and then expanded and coalesced. Over drusen (n = 45, all calcified), RPE was continuous and thin, photoreceptors were short or absent, and initially intact ELM descended where RPE was absent. In persistent hyperFAF within atrophy and in the OJZ, the RPE was continuous and dysmorphic, photoreceptors were present and short, and BLamD was thick. In the IJZ, mottled FAF corresponded to dissociated RPE atop persistent BLamD. Overall linear growth rate (0.198 mm/ year) typified multifocal GA.

Conclusions

FAF in GA is locally multifactorial, with photoreceptor shortening potentially promoting hyperFAF by increasing incoming excitation light available to RPE fluorophores. RPE dysmorphia may lead to either longer or shorter pathlength for excitation light. At both atrophy initiation and expansion Müller glia are major participants.

Oral Antioxidant and Lutein/Zeaxanthin Supplements Slow Geographic Atrophy Progression to the Fovea in Age-Related Macular Degeneration

PURPOSE

To determine whether oral micronutrient supplementation slows geographic atrophy (GA) progression in age-related macular degeneration (AMD).

DESIGN

Post hoc analysis of Age-Related Eye Disease Study (AREDS) and AREDS2, multicenter randomized placebo-controlled trials of oral micronutrient supplementation, each with 2 × 2 factorial design.

PARTICIPANTS

A total of 392 eyes (318 participants) with GA in AREDS and 1210 eyes (891 participants) with GA in AREDS2.

METHODS

The AREDS participants were randomly assigned to oral antioxidants (500 mg vitamin C, 400 IU vitamin E, 15 mg β-carotene), 80 mg zinc, combination, or placebo. The AREDS2 participants were randomly assigned to 10 mg lutein/2 mg zeaxanthin, 350 mg docosahexaenoic acid/650 mg eicosapentaenoic acid, combination, or placebo. Consenting AREDS2 participants were also randomly assigned to alternative AREDS formulations: original; no beta-carotene; 25 mg zinc instead of 80 mg; both.

MAIN OUTCOME MEASURES

(1) Change in GA proximity to central macula over time and (2) change in square root GA area over time, each measured from color fundus photographs at annual visits and analyzed by mixed-model regression according to randomized assignments.

RESULTS

In AREDS eyes with noncentral GA (n = 208), proximity-based progression toward the central macula was significantly slower with randomization to antioxidants versus none, at 50.7 μm/year (95% confidence interval [CI], 38.0-63.4 μm/year) versus 72.9 μm/year (95% CI, 61.3-84.5 μm/year; P = 0.012), respectively. In AREDS2 eyes with noncentral GA, in participants assigned to AREDS antioxidants without β-carotene (n = 325 eyes), proximity-based progression was significantly slower with randomization to lutein/zeaxanthin versus none, at 80.1 μm/year (95% CI, 60.9-99.3 μm/year) versus 114.4 μm/year (95% CI, 96.2-132.7 μm/year; P = 0.011), respectively. In AREDS eyes with any GA (n = 392), area-based progression was not significantly different with randomization to antioxidants versus none (P = 0.63). In AREDS2 eyes with any GA, in participants assigned to AREDS antioxidants without β-carotene (n = 505 eyes), area-based progression was not significantly different with randomization to lutein/zeaxanthin versus none (P = 0.64).

CONCLUSIONS

Oral micronutrient supplementation slowed GA progression toward the central macula, likely by augmenting the natural phenomenon of foveal sparing.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Small Hyperreflective Retinal Foci as in vivo imaging feature of resident microglia activation in geographic atrophy

Geographic atrophy (GA), the atrophic late stage of age-related macular degeneration (AMD), is one of the leading causes of vision loss in developed countries. Based on genetic, histological and preclinical studies, the role of the innate immune system in the development and progression of GA is well established. Microglia, the principal resident immune cells, are recognized as key players in innate immunity and contributors to AMD development. Optical coherence tomography (OCT) allows to identify small hyperreflective retinal foci (HRF) with specific features known as aggregates of activated microglial cells as possible in vivo imaging feature of local neuroretinal inflammation. The purpose of this study was to evaluate the presence and amount of small HRF in the eyes of patients with different macular atrophic phenotypes. Patients with GA in both eyes (bilateral GA: B-GA group), patients with GA in one eye and macular new vessels (MNV) in the fellow-eye (unilateral GA: U-GA group) and patients with extensive macular atrophy with pseudodrusen (EMAP), a rare and aggressive variant of atrophic AMD, were retrospectively analyzed. HRF, defined as isolated punctiform elements of small dimensions (≤30 μm) with intermediate reflectivity (similar to that of the nerve fiber layer) and without a shadow cone, were manually identified and quantified. The amount of HRF was correlated to best corrected visual acuity (BCVA), GA lesion size, measured both at near infrared reflectance (NIR), and blue wavelength fundus autofluorescence (FAF) images, to some GA features (multifocal versus unifocal GA; presence versus absence of foveal sparing) and to central retinal thickness (CRT). Forty-six patients (26 in the B-GA group, 16 in the U-GA group and 4 in the EMAP group) were studied. Patients with EMAP were younger compared to patients with B-GA and to patients with U-GA (63.5 ± 6.8 years vs 80.4 ± 8.4 years B-GA, and vs 83.3 ± 6.1 years U-GA; p = 0.0004 and p= <0.0001, respectively). Mean BCVA, mean GA area at NIR and at FAF images, foveal sparing and multifocal versus unifocal GA distribution and mean CRT were not significantly different among groups. GA area was wider on NIR versus FAF in all groups, significantly in B-GA and U-GA groups (11.7 ± 7.6 mm2 vs 10.6 ± 7.1 mm2, p = 0.0087 in B-GA; 7.8 ± 9.2 mm2 vs 7.7 ± 9.4 mm2, p = 0.004 in U-GA). The number of HRF was significantly higher in U-GA compared to B-GA and to EMAP (47.4 ± 7.1 vs 31.6 ± 7.3 B-GA and 28.0 ± 4.9 EMAP, p < 0.0001 for both), while mean HRF number did not significantly differ between B-GA and EMAP (p = 0.1960). HRF count correlated only to CRT, positively in B-GA and negatively in U-GA group. The increase of small HRF, which mirrors retinal microglial activation, characterizes eyes with unilateral GA (and MNV in the fellow eye) but not eyes with bilateral GA or EMAP. The role of activated microglia in the retina of GA eyes needs to be better investigated, mainly considering the actual and new therapeutic strategies with which to reduce either the development or progression of the atrophic macular changes.

Bilateral Involvement of Age-Related Macular Degeneration in South Korea: Findings from the Korea National Health and Nutrition Examination Survey 2017-2020

PURPOSE

To evaluate the bilateral involvement of age-related macular degeneration (AMD) in South Koreans.

METHODS

This was a cross-sectional study of the Korean National Health and Nutrition Examination Survey (2017-2020). This study included 13,737 participants aged 40 years or older. Participants were evaluated to determine the prevalence of bilateral early and late AMD. In cases in which exudative AMD or geographic atrophy (GA) was diagnosed in a single eye, the fellow eye was evaluated to determine the presence and type of late AMD.

RESULTS

The overall prevalence of bilateral AMD was 6.12% (95% confidence interval [CI], 5.63-6.61). The prevalence of bilateral early AMD was 5.71% (95% CI, 5.24-6.18), while that of late AMD was 0.14% (95% CI, 0.08-0.20). The prevalence of the bilateral involvement of late AMD increased with age. A 0.02% prevalence (95% CI, 0.00-0.06) of late AMD was observed in participants aged 50-59. The prevalence increased to 0.08% (95% CI, 0.00-0.18) in participants aged 60-69, while the prevalence in participants aged 70-79 and over 80 was 0.45% (95% CI, 0.12-0.78) and 1.97% (95% CI, 0.75-3.19), respectively. The prevalence of early AMD in one eye and late AMD in the fellow eye was 0.26% (95% CI, 0.16-0.36).

CONCLUSIONS

An assessment of the incidence of AMD revealed that a significant number of persons had bilateral involvement. The treatment burden may significantly increase for participants with bilateral late AMD compared to those with unilateral involvement. Therefore, the study may be helpful with the establishment of private and national insurance policies.

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.

CHARACTERISTICS PREDICTIVE OF FELLOW-EYE GEOGRAPHIC ATROPHY WITHOUT NEOVASCULARIZATION IN UNILATERAL TYPE 3 MACULAR NEOVASCULARIZATION

PURPOSE

To evaluate the predictive characteristics of fellow-eye geographic atrophy (GA) without neovascularization in patients with unilateral Type 3 macular neovascularization.

METHODS

This retrospective study included 84 patients who were diagnosed with unilateral Type 3 macular neovascularization. Patients who developed fellow-eye neovascularization and those exhibiting GA without neovascularization at the final follow-up were included in the neovascularization and GA groups, respectively. The patient demographics and baseline fellow-eye characteristics were compared between the two groups.

RESULTS

The mean follow-up period was 40.5 ± 11.5 months after diagnosis. Patients included in the GA group (n = 28) were significantly older (mean 77.4 ± 5.2 years vs. 74.2 ± 5.8 years, P = 0.016), had significantly thinner subfoveal choroidal thickness (mean 109.4 ± 36.8 µ m vs. 173.1 ± 77.6 µ m, P < 0.001), and had a significantly higher incidence of baseline GA (39.3% vs. 16.1%, P = 0.019) than those included in the neovascularization group (n = 56). In the multivariate analysis, subfoveal choroidal thickness showed a close negative association with the risk of GA rather than neovascularization ( P = 0.004, β = 0.982, 95% confidence interval = 0.970-0.994).

CONCLUSION

In patients with unilateral Type 3 macular neovascularization, older age, the presence of GA, and a thin choroid in the fellow eye were found to be indicative of a higher probability of progression toward fellow-eye GA instead of neovascularization may be potential candidates for future complement inhibitor treatments targeting fellow-eye GA.

The influence of the topographic location of geographic atrophy on vision-related quality of life in nonexudative age-related macular degeneration

PURPOSE

To examine associations between the topographic distribution of geographic atrophy (GA) and vision-related quality of life (VRQoL).

METHODS

This study included 237 eyes from 161 participants in the Age-Related Eye Disease Study (AREDS). GA lesions were manually delineated with color fundus photographs obtained by the AREDS Research Group and atrophic area was measured in an Early Treatment Diabetic Retinopathy Study (ETDRS) grid. VRQoL was measured using the National Eye Institute Visual Function Questionnaire (NEI-VFQ). Area of atrophy in the ETDRS grid subfields was correlated with VRQoL by linear regression modeling.

RESULTS

The average area of atrophy in the better and worse eye was 3.43mm² and 7.15mm² respectively. In multivariable analysis, VRQoL was not associated with total area of atrophy in the better eye (β, - 0.53; 95% confidence interval [CI], - 1.11 to 0.05; P = 0.07) or worse eye (β, 0.12; 95% CI, - 0.32 to 0.55; P = 0.59). However, area of atrophy in the central 1-mm-diameter zone of the better eye was significantly associated with VRQoL when the ETDRS subfields were examined individually (β, - 14.57; 95% CI, - 27.12 to - 2.02; P = 0.023), grouped into quadrants (β, - 18.35; 95% CI, - 30.03 to - 6.67; P = 0.002), inner and outer zones (β, - 17.26; 95% CI, - 29.38 to - 5.14; P = 0.006), or vertical and horizontal zones (β, - 18.97; 95% CI, - 30.18 to - 7.77; P = 0.001).

CONCLUSION

In patients with GA, greater area of atrophy in the central 1-mm-diameter zone of the better eye was independently associated with lower VRQoL, while total area of atrophy in the better or worse eye was not.

Predicting Topographic Disease Progression and Treatment Response of Pegcetacoplan in Geographic Atrophy Quantified by Deep Learning

PURPOSE

To identify disease activity and effects of intravitreal pegcetacoplan treatment on the topographic progression of geographic atrophy (GA) secondary to age-related macular degeneration quantified in spectral-domain OCT (SD-OCT) by automated deep learning assessment.

DESIGN

Retrospective analysis of a phase II clinical trial study evaluating pegcetacoplan in GA patients (FILLY, NCT02503332).

SUBJECTS

SD-OCT scans of 57 eyes with monthly treatment, 46 eyes with every-other-month (EOM) treatment, and 53 eyes with sham injection from baseline and 12-month follow-ups were included, in a total of 312 scans.

METHODS

Retinal pigment epithelium loss, photoreceptor (PR) integrity, and hyperreflective foci (HRF) were automatically segmented using validated deep learning algorithms. Local progression rate (LPR) was determined from a growth model measuring the local expansion of GA margins between baseline and 1 year. For each individual margin point, the eccentricity to the foveal center, the progression direction, mean PR thickness, and HRF concentration in the junctional zone were computed. Mean LPR in disease activity and treatment effect conditioned on these properties were estimated by spatial generalized additive mixed-effect models.

MAIN OUTCOME MEASURES

LPR of GA, PR thickness, and HRF concentration in μm.

RESULTS

A total of 31,527 local GA margin locations were analyzed. LPR was higher for areas with low eccentricity to the fovea, thinner PR layer thickness, or higher HRF concentration in the GA junctional zone. When controlling for topographic and structural risk factors, we report on average a significantly lower LPR by -28.0% (95% confidence interval [CI], -42.8 to -9.4; P = 0.0051) and -23.9% (95% CI, -40.2 to -3.0; P = 0.027) for monthly and EOM-treated eyes, respectively, compared with sham.

CONCLUSIONS

Assessing GA progression on a topographic level is essential to capture the pathognomonic heterogeneity in individual lesion growth and therapeutic response. Pegcetacoplan-treated eyes showed a significantly slower GA lesion progression rate compared with sham, and an even slower growth rate toward the fovea. This study may help to identify patient cohorts with faster progressing lesions, in which pegcetacoplan treatment would be particularly beneficial. Automated artificial intelligence-based tools will provide reliable guidance for the management of GA in clinical practice.

Adherence to a Mediterranean Diet and Geographic Atrophy Enlargement Rate: Age-Related Eye Disease Study 2 Report 29

PURPOSE

To determine whether closer adherence to a Mediterranean diet was associated with altered speed of geographic atrophy (GA) enlargement.

DESIGN

Post hoc analysis of a cohort within the Age-Related Eye Disease Study 2.

PARTICIPANTS

The study included 1155 eyes (850 participants; mean age, 74.9 years) with GA at 2 or more visits.

METHODS

Geographic atrophy area was measured from color fundus photographs at annual visits. An alternative Mediterranean Diet index (aMedi) was calculated for each participant by food frequency questionnaire. Mixed-model regression of square root GA area was performed by aMedi.

MAIN OUTCOME MEASURES

Change in square root of GA area over time.

RESULTS

Over a mean follow-up of 3.1 years, the mean GA enlargement rate was 0.282 mm/year (95% confidence interval, 0.270-0.293). Enlargement was significantly slower in those with higher aMedi at 0.256 mm/year (0.236-0.276), 0.290 (0.268-0.311), and 0.298 (0.280-0.317; P = 0.008) for aMedi tertiles 3, 2, and 1, respectively. Of the 9 aMedi components considered separately, significant differences in enlargement rate were observed for 4 (whole fruit [P = 0.0004], red meat [P = 0.0002], alcohol [P = 0.006], and monounsaturated fatty acid to saturated fatty acid ratio ([MUFA:SFA] [P = 0.040]) but not for fish (P = 0.14). Enlargement was slower in those with higher whole fruit, lower red meat, moderate alcohol, and higher MUFA:SFA intake. In the 768 eyes with noncentral GA, aMedi was not associated with slower progression to central involvement: hazard ratios were 1.11 (0.83-1.48) and 0.95 (0.71-1.26) for tertiles 2 and 3, respectively.

CONCLUSIONS

A Mediterranean-type diet was associated with slower GA enlargement. Diet patterns like this may therefore lead to clinically meaningful delays in vision loss. Several components seemed to contribute most to this association in a pattern that differed from those most associated with decreased progression to GA. Hence, the Mediterranean diet is associated with protection against both faster progression to GA and faster enlargement of GA but for partially distinct reasons. These findings may help inform evidence-based dietary recommendations. Understanding the mechanisms responsible may provide insights into the underlying biology and lead to the development of nutritional supplements.

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.

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.