CLINICAL ENDPOINTS FOR THE STUDY OF GEOGRAPHIC ATROPHY SECONDARY TO AGE-RELATED MACULAR DEGENERATION

A Novel Management Challenge in Age-Related Macular Degeneration: Artificial Intelligence and Expert Prediction of Geographic Atrophy

PURPOSE

The progression of geographic atrophy (GA) secondary to age-related macular degeneration is highly variable among individuals. Prediction of the progression is critical to identify patients who will benefit most from the first treatments currently approved. The aim of this study was to investigate the value and difference in predictive power between ophthalmologists and artificial intelligence (AI) in reliably assessing individual speed of GA progression.

DESIGN

Prospective, expert and AI comparison study.

PARTICIPANTS

Eyes with natural progression of GA from a prospective study (NCT02503332).

METHODS

Ophthalmologists predicted yearly growth speed of GA as well as selected the potentially faster-growing lesions from 2 eyes based on fundus autofluorescence (FAF), near-infrared reflectance (NIR), and OCT. A deep learning algorithm predicted progression solely on the baseline OCT (Spectralis, Heidelberg Engineering).

MAIN OUTCOME MEASURES

Accuracy, weighted κ, and concordance index (c-index) between the prediction made by ophthalmology specialists, ophthalmology residents, and the AI algorithm.

RESULTS

A total of 134 eyes of 134 patients from a phase II clinical trial were included; among them, 53 were from the sham arm, and 81 were from untreated fellow eyes. Four ophthalmologists performed 2880 gradings. Human experts reached an accuracy of 0.37, 0.43, and 0.41 and a κ of 0.06, 0.16, and 0.18 on FAF, NIR + OCT, and FAF + NIR + OCT, respectively. On a pairwise comparison task, human experts achieved a c-index of 0.62, 0.59, and 0.60. Automated AI-based analysis reached an accuracy of 0.48 and κ of 0.23 on the first task, and c-index of 0.69 on the second task solely utilizing OCT imaging.

CONCLUSIONS

Prediction of individual progression will become an important task for patient counseling, most importantly with the treatments becoming available. Human gradings improved with the availability of OCT. However, automated AI performed better than ophthalmologists in several comparisons. Artificial intelligence-supported decisions improve clinical precision, access to timely care for the community, and socioeconomic feasibility in the management of the leading cause of irreversible vision loss.

FINANCIAL DISCLOSURE(S)

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

Retinal Thickness Analysis Using Optical Coherence Tomography: Diagnostic and Monitoring Applications in Retinal Diseases

Retinal thickness analysis using optical coherence tomography (OCT) has become an indispensable tool in retinal disease management, providing high-resolution quantitative data for diagnosis, monitoring, and treatment planning. This analysis has been found to be particularly useful for both diagnostic and monitoring purposes across a wide range of retinal diseases, enabling precise disease characterization and treatment evaluation. This paper explores its applications across major retinal conditions, including age-related macular degeneration, diabetic retinopathy, retinal vein occlusion, and inherited retinal diseases. Emerging roles in other diseases such as neurodegenerative diseases and retinal drug toxicity are also highlighted. Despite challenges such as variability in measurements, segmentation errors, and interpretation difficulties, advancements in artificial intelligence and machine learning have significantly improved accuracy and efficiency. The integration of retinal thickness analysis with telemedicine platforms and standardized protocols further underscores its potential in delivering personalized care and enabling the early detection of ocular and systemic diseases. Retinal thickness analysis continues to play a pivotal and growing role in both clinical practice and research, bridging the gap between ophthalmology and broader medical fields.

Associations Between Contrast Sensitivity, Optical Coherence Tomography Features and Progression From Intermediate to Late Age-related Macular Degeneration

PURPOSE

Establishing associations between structure, function, and clinical outcomes in intermediate age-related macular degeneration (iAMD) remains an unmet need. This study aims to (1) cross-sectionally investigate the relationships between optical coherence tomography (OCT) biomarkers and quantitative contrast sensitivity function (qCSF)-measured contrast sensitivity (CS), and (2) longitudinally assess their relationship with progression from iAMD to late stages of the disease.

DESIGN

Cross-sectional and cohort study.

METHODS

Our study was conducted at Massachusetts Eye and Ear (Boston, MA, USA) and included eyes with (1) baseline diagnosis of iAMD, (2) same-day OCT and qCSF test, (3) visual acuity ≥20/200 Snellen, and (4) 24+ months of follow-up. qCSF metrics included the area under the logCSF curve, contrast acuity, and CS thresholds at 1- to 18-cycle-per-degree (cpd). Two independent graders reviewed macular OCT scans for various biomarkers, and outer nuclear layer (ONL) thickness and retinal pigment epithelium (RPE) volume were measured. Progression to wet AMD or geographic atrophy (GA) was confirmed using imaging studies. Generalized linear mixed-effects models assessed associations between qCSF and OCT biomarkers, while Cox regression models evaluated their association with progression to late AMD.

RESULTS

We included 205 iAMD eyes from 134 patients (age: 73 [69-78] years; 63% female). Higher RPE volume in the central subfield and a greater number of intraretinal hyperreflective foci were associated with reduced area under the logCSF curve, contrast acuity, and CS at 6 to 12 cpd (P < .05). ONL thinning in the inner ring and a greater number of intraretinal hyperreflective foci were associated with reduced CS at 1 and 3 cpd (P < .05). During follow-up, 35 eyes developed wet AMD (17%) and 53 progressed to GA (26%). subretinal drusenoid deposit, ONL thinning in the inner ring, and reduced CS at 1.5 cpd were associated with wet AMD (P < .05). Higher RPE volume in the inner ring, hyporeflective drusen cores, subretinal drusenoid deposit, higher HRF count, and reduced CS at 1 cpd were associated with GA (P < .05).

CONCLUSIONS

Our study reveals significant structure-function relationships between OCT biomarkers and qCSF-measured CS in iAMD. These findings highlight the impact of AMD alterations on CS function and offer valuable insights for patient stratification and prognostication in research and clinical settings.

Interreader and Intermodality Variability in Macular Atrophy Quantification in Neovascular Age-related Macular Degeneration: Comparison of 6 Imaging Modalities

PURPOSE

Macular atrophy is a common complication in neovascular age-related macular degeneration (AMD) and is associated with poorer visual outcomes. This study evaluated interreader and intermodality variability in measuring macular atrophy in previously treated neovascular AMD eyes without exudation using 6 imaging modalities.

DESIGN

Prospective, cohort study.

PARTICIPANTS

Thirty participants with previously treated neovascular AMD showing no signs of exudation at the time of enrollment and exhibiting macular atrophy.

METHODS

During the same clinic visit, patients were imaged using 6 different imaging modalities: color fundus photography (CFP; Clarus, Carl Zeiss Meditec), near-infrared imaging (NIR; Spectralis, Heidelberg Engineering), structural OCT (Spectralis, Heidelberg Engineering), green fundus autofluorescence (GAF; Clarus, Carl Zeiss Meditec), blue fundus autofluorescence (BAF; Spectralis, Heidelberg Engineering), and pseudocolor imaging (MultiColor; Spectralis, Heidelberg Engineering). Two readers independently measured the macular atrophy area.

MAIN OUTCOME MEASURES

Interreader and intermodality agreement.

RESULTS

The 95% coefficient of repeatability was 5.98 mm2 for CFP, 4.46 mm2 for MultiColor, 3.90 mm2 for BAF, 3.92 mm2 for GAF, 4.86 mm2 for NIR, and 3.55 mm2 for OCT. Similarly, the coefficient of variation was lowest for OCT-based grading at 0.08 and highest for NIR-based grading at 0.28. Accordingly, the intraclass correlation coefficient was 0.742 for CFP, 0.805 for MultiColor, 0.857 for BAF, 0.850 for GAF, 0.755 for NIR, and 0.917 for OCT. The 6 different imaging modalities presented measurements with different mean values, with only a limited number of comparisons not significantly different between the instruments, although measurements were correlated. The largest size of macular atrophy was measured with structural OCT-based grading (median = 4.65 mm2; interquartile range [IQR] = 4.78 mm2) and the smallest was with CFP-based grading (median = 3.86 mm2; IQR = 5.06 mm2). Inconsistencies arose from various factors.

CONCLUSIONS

In patients with neovascular AMD, macular atrophy measurements vary significantly depending on the imaging technique used. Color fundus photography-based assessments yielded the smallest macular atrophy sizes, whereas structural OCT-based assessments produced the largest. These discrepancies stem from both the inherent limitations of each modality in assessing retinal pigment epithelial atrophy and factors related to neovascularization, such as the coexistence of fibrosis.

FINANCIAL DISCLOSURE(S)

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

Deep Learning to Predict the Future Growth of Geographic Atrophy from Fundus Autofluorescence

Purpose

The region of growth (ROG) of geographic atrophy (GA) throughout the macular area has an impact on visual outcomes. Here, we developed multiple deep learning models to predict the 1-year ROG of GA lesions using fundus autofluorescence (FAF) images.

Design

In this retrospective analysis, 3 types of models were developed using FAF images collected 6 months after baseline to predict the GA lesion area (segmented lesion mask) at 1.5 years, FAF images collected at baseline and 6 months to predict the GA lesion at 1.5 years, and FAF images collected 6 months after baseline to predict the GA lesion at 1 and 1.5 years. The 1-year ROG from the 6-month visit was derived by taking the difference between the GA lesion area (segmented lesion mask) at the 1.5-year and 6-month visits.

Participants

Patients enrolled in the following lampalizumab clinical trials and prospective observational studies: NCT02247479, NCT02247531, NCT02479386, and NCT02399072.

Methods

Datasets of study eyes from 597 patients were split into model training (310), validation (78), and test sets (209), stratified by baseline or initial lesion area, lesion growth rate, foveal involvement, and focality. Deep learning experiments were performed using the 2-dimensional U-Net; whole-lesion and multiclass models were developed.

Main Outcome Measures

The performance of the models was evaluated by calculating the Dice score, coefficient of determination (R2), and the squared Pearson correlation coefficient (r2) between the true and derived GA lesion 1-year ROG.

Results

The model using baseline and 6-month FAF images to predict GA lesion enlargement at 1.5 years had the best performance for the derived 1-year ROG. Mean Dice scores were 0.73, 0.68, and 0.70 in the training, validation, and test sets, respectively. The R2 (0.77, 0.53, and 0.79) and r2 (0.83, 0.61, and 0.79) showed similar trends across the 3 sets.

Conclusions

These findings show the potential of using baseline and/or 6-month visit FAF images to predict 1-year GA ROG using a deep learning approach. This work could potentially help support decision-making in clinical trials and more informed treatment decisions in clinical practice.

Financial Disclosures

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

Repeatability of Microperimetry in Areas of Retinal Pigment Epithelium and Photoreceptor Loss in Geographic Atrophy Supported by Artificial Intelligence-Based Optical Coherence Tomography Biomarker Quantification

PURPOSE

Growing interest in microperimetry (MP) or fundus-controlled perimetry as a targeted psychometric testing method in geographic atrophy (GA) is warranted because of the disease subclinical/extrafoveal appearance or preexisting foveal loss with visual acuity becoming unreliable. We provide comprehensive pointwise test-retest repeatability reference values on the most widely used MP devices and combine them with targeted testing in areas of retinal pigment epithelium (RPE) as well as photoreceptor (PR) integrity loss, guiding the interpretation of sensitivity loss during the long-term follow-up of patients with GA.

DESIGN

Prospective reliability study.

METHODS

Patients with GA underwent consecutive testing on CenterVue (iCare) MAIA and NIDEK MP3 devices. Obtained pointwise sensitivity (PWS) measurements were spatially coregistered to an optical coherence tomography volume scan acquired during the same visit. Areas with RPE and PR integrity loss, drusen, and PR thickness as well as the volume of hyperreflective foci where identified and quantified using a set of validated deep learning-based algorithms. Test-retest repeatability was assessed according to areas defined by biomarker-specific morphologic changes using Bland-Altmann coefficients of repeatability. Furthermore, the interdevice correlation, the repeatability of scotoma point detection, and any potential effects on fixation stability were assessed.

RESULTS

Nine hundred stimuli per device from 20 subjects were included. Identical overall PWS test-retest variance could be detected for MAIA (±6.57) and MP3 (±6.59). PR integrity loss was associated with a higher test-retest variance on both devices (MAIA, P = .002; MP3, P < .001). Higher coefficients of repeatability for stimuli in areas presenting RPE loss (±10.99 vs ±5.34) or hyperreflective foci (±9.21 vs ±6.25) could only be detected on MP3 examinations (P < .001 and P = .01, respectively). An excellent intradevice correlation (MAIA 0.94 [0.93-0.95], MP3 0.94 [0.94-0.95]) and a good mean interdevice correlation (0.84 [0.53-0.92]) were demonstrated. The chosen device, run order, or absence of foveal sparing had no significant effect on fixation stability.

CONCLUSION

Areas presenting automatically quantified PR integrity loss with and without underlying RPE loss are associated with higher test-retest variance for both MAIA and MP3. These findings are crucial for an accurate interpretation of GA progression during long-term follow-up and the planning of future trials with MP testing as functional study endpoint.

Structure-Function Relationships in Geographic Atrophy Based on Mesopic Microperimetry, Fundus Autofluorescence, and Optical Coherence Tomography

Purpose

To examine relationships between retinal structure and visual function in geographic atrophy (GA) by analyzing spatial agreement between absolute scotomas and macular structure, focusing on (1) choroidal hypertransmission, a key feature of complete retinal pigment epithelium and outer retinal atrophy (cRORA), and (2) fundus autofluorescence (FAF)-defined GA.

Methods

Mesopic microperimetry (using a novel T-shaped pattern) and multimodal imaging were recorded longitudinally in a phase II GA trial. Horizontal and vertical optical coherence tomography (OCT) line scans (corresponding to the T axes) were graded for choroidal hypertransmission; FAF images were graded for GA. Spatial concordance between zones of absolute scotoma and atrophy was quantified by the Dice similarity coefficient (DSC).

Results

The analysis population comprised 24 participants (mean follow-up 26.8 months). For concordance between absolute scotoma and choroidal hypertransmission, estimated mean DSC was 0.70 (95% confidence interval [CI], 0.64-0.77). This was significantly higher than for FAF-defined GA (0.67; 95% CI, 0.61-0.74; estimated mean difference = 0.03, 95% CI, 0.02-0.05, P < 0.001). Mean OCT choroidal reflectivity was strongly associated with likelihood and severity of scotoma.

Conclusions

Spatial concordance between absolute scotomas and GA structural features is moderately high and slightly higher for choroidal hypertransmission than FAF-defined GA. This supports choroidal hypertransmission, a key cRORA feature, as an outcome measure in interventional trials. OCT provides more information to explain visual function than FAF alone. However, given some discordance for both structural features, performing microperimetry alongside imaging remains important.

Translational Relevance

These findings provide insights into the complex relationship between retinal structure and visual function and contribute to a nuanced understanding of outcome measures.

Intravitreal Administration of Avacincaptad Pegol in a Nonhuman Primate Model of Dry Age-Related Macular Degeneration

The lack of effective treatments for dry age-related macular degeneration (AMD) is in part due to a lack of a preclinical animal model that recapitulates features of the clinical state including macular retinal pigment epithelium (RPE) degeneration, also known as geographic atrophy (GA). A nonhuman primate model of GA was developed and its responsiveness to an approved treatment, avacincaptad pegol (ACP), a complement C5 inhibitor, was evaluated. Intravitreal (ivt) administration of sodium iodate (SI) into one eye of male Macaca fascicularis leads to retinal areas (mm2) of hyper- or hypo-autofluorescence. Qualitative changes to the retinal structure over time were observed with spectral domain optical coherence tomography (OCT). Six days after SI administration, prior to treatment, mean (± SEM) GA of all eyes was 8.2 ± 1.8 mm2. Following randomization to treatment groups, either vehicle or ACP was ivt injected and treatment was continued every 4 weeks, for a total of four treatments. Sixteen weeks after SI administration, the GA area in vehicle-treated eyes was 18.9 ± 6.6 mm2, whereas GA in ACP-treated eyes was 11.4 ± 4.0 mm2, a reduction by about 36%. Increased, followed by decreased, overall macular thickness was observed with OCT over time following SI administration. Treatment with ACP did not change alter macular thickness thinning. Geographic atrophy-like lesions that expand over time are observed following SI administration. The current macaque model could be utilized to further explore the mechanism of dry AMD and to develop more novel therapeutics.

Age-related macular degeneration: natural history revisited in geographic atrophy

Progression of geographic atrophy varies significantly based on individual and lesion characteristics. Much research has strived to understand prognostic indicators of lesion progression over time, yet integrating findings to date may pose a challenge to clinicians. This review strives to synthesize current knowledge on genetic, behavioral, structural, and functional factors that influence geographic atrophy across the lifetime. Further, it highlights how vision-related quality of life allows for a more holistic appraisal of the impact of geographic atrophy on everyday functioning. The ultimate aim of this paper is to aid clinicians in counseling patients on medical management as well as providing accurate disease prognostication tailored to the individual patient.

Artificial intelligence in assessing progression of age-related macular degeneration

The human population is steadily growing with increased life expectancy, impacting the prevalence of age-dependent diseases, including age-related macular degeneration (AMD). Health care systems are confronted with an increasing burden with rising patient numbers accompanied by ongoing developments of therapeutic approaches. Concurrent advances in imaging modalities provide eye care professionals with a large amount of data for each patient. Furthermore, with continuous progress in therapeutics, there is an unmet need for reliable structural and functional biomarkers in clinical trials and practice to optimize personalized patient care and evaluate individual responses to treatment. A fast and objective solution is Artificial intelligence (AI), which has revolutionized assessment of AMD in all disease stages. Reliable and validated AI-algorithms can aid to overcome the growing number of patients, visits and necessary treatments as well as maximize the benefits of multimodal imaging in clinical trials. Therefore, there are ongoing efforts to develop and validate automated algorithms to unlock more information from datasets allowing automated assessment of disease activity and disease progression. This review aims to present selected AI algorithms, their development, applications and challenges regarding assessment and prediction of AMD progression.

Characterizing Patient Perceptions of Living with Geographic Atrophy: The Global Geographic Atrophy Insights Survey

Background

Geographic atrophy (GA) is an advanced form of age-related macular degeneration leading to irreversible vision loss and negative impacts on quality of life.

Methods

To assess the experiences of living with GA, the Geographic Atrophy Insights Survey (GAINS) was conducted between October 12, 2021, and December 10, 2021, captured the responses of individuals ≥60 years with a self-reported GA diagnosis residing in the United States, Canada, Australia, and six European countries. Survey questions focused on the perceptions of individuals living with GA and covered six themes: speed of disease progression, effect on independence, impact on quality of life, emotional toll of GA, misconceptions and need for further education about GA, and clinician interactions. An exploratory comparison between participants with unilateral and bilateral GA was conducted.

Results

The survey included 203 individuals with a mean age of 70 years; 42% had bilateral GA. Most respondents (77%) agreed ("strongly" or "somewhat agreed") that GA impacted their vision faster than expected, and 68% agreed that it is hard to enjoy life fully the way they did before GA diagnosis. Regarding comparisons between individuals with bilateral and unilateral GA, both groups reported similar "major" or "moderate" negative impacts on their ability to drive (73% vs 75%, respectively), followed by the ability to read (66% vs 71%), and ability to travel as much as they would prefer (62% vs 62%). Among participants, 49% and 56% of respondents with bilateral and unilateral GA, respectively, reported major/moderate negative impacts on self-confidence and 40% of both cohorts reported major/moderate negative impacts on mental health.

Conclusion

Our survey provides further insight on the burden experienced by individuals living with GA. We find similar responses between unilateral and bilateral GA groups, highlighting the impact GA may have on an individual's quality of life even when only one eye is affected.

Efficacy and safety of complement inhibitors in patients with geographic atrophy associated with age-related macular degeneration: a network meta-analysis of randomized controlled trials

Importance

Clinical trials in recent years have shown significant effectiveness of complement inhibitors for geographic atrophy (GA) treatment. Two complement inhibitor drugs have been approved by the Food and Drug Administration (FDA).

Objective

to compare and rank the different complement inhibitors in the treatment of GA secondary to age-related macular degeneration (AMD).

Data sources

A systematic literature search was conducted in the Cochrane Central, Web of Science Core Collection, PubMed, LWW Medical Journals, ClinicalTrials.gov, and WHO ICTRP from inception to October 2023.

Study selection

All randomized clinical trials evaluating the effectiveness of complement inhibitors in patients diagnosed with secondary GA in AMD were identified.

Data extraction and synthesis

This study followed Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) network meta-analysis Checklist of Items and the Cochrane Risk of Bias Assessment Tool for assessing the study quality. Multiple authors independently coded all titles and abstracts, reviewed full-text articles against the inclusion and exclusion criteria, and resolved all discrepancies by consensus. Random-effects network meta-analyses were applied. Bayesian network meta-analysis was performed using the BUGSnet package in R (4.2.0).

Main outcomes and measures

The primary efficacy outcome was the change in GA lesion size (mm2) from baseline to month 12. The secondary efficacy outcome was the mean change in best-corrected visual acuity (BCVA) from baseline to month 12. Safety outcome measures included the number of subjects with serious adverse events (SAEs) and macular neovascularization (MNV).

Results

Ten randomized controlled trials including 4,405 participants and five complement inhibitors were identified. Comparison with sham and SUCRA analysis showed that avacincaptad pegol 2 mg (MD: -0.58, 95% CrI: -0.97 to -0.18, SUCRA: 93.55), pegcetacoplan monthly (MD: -0.38, 95% CrI: -0.57 to -0.20, SUCRA: 81.37), and pegcetacoplan every other month (MD: -0.30, 95% CrI: -0.49 to -0.11, SUCRA: 70.16) have significant changes in GA lesion reduction. No treatments showed significant changes in BCVA and SAE compared with sham. Pegcetacoplan monthly (OR: 4.30, 95% CrI: 1.48-16.72) increased the risk of MNV. Avacincaptad pegol 2 mg demonstrated favorable outcomes in terms of SAE and MNV.

Conclusion and relevance

Avacincaptad pegol 2 mg is the most effective complement inhibitor with better safety for the treatment of GA secondary to AMD.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022351515, Identifier PROSPERO CRD42022351515.

Vision Loss Reduction with Avacincaptad Pegol for Geographic Atrophy: A 12-Month Post Hoc Analysis of the GATHER1 and GATHER2 Trials

PURPOSE

To evaluate the impact of reduction in geographic atrophy (GA) lesion growth on visual acuity in the GATHER trials using categorical outcome measures.

DESIGN

Randomized, double-masked, sham-controlled phase 3 trials.

PARTICIPANTS

Aged ≥50 years with noncenter point-involving GA and best-corrected visual acuity (BCVA) of 25 to 80 ETDRS letters in the study eye.

METHODS

GATHER1 consisted of 2 parts. In part 1, 77 patients were randomized 1:1:1 to avacincaptad pegol (ACP) 1 mg, ACP 2 mg, and sham. In part 2, 209 patients were randomized 1:2:2 to ACP 2 mg, ACP 4 mg, and sham. In GATHER2, patients were randomized 1:1 to ACP 2 mg (n = 225) and sham (n = 223). A post hoc analysis of 12-month data for pooled ACP 2 mg and sham groups is reported.

MAIN OUTCOME MEASURES

Proportion of study eyes that experienced ≥10-, ≥15-, or ≥20-BCVA ETDRS letter loss from baseline to month 12; time-to-event analysis of persistent vision loss of ≥10, ≥15, or ≥20 BCVA letters from baseline at ≥2 consecutive visits over 12 months; proportion of study eyes with BCVA loss to a level below driving eligibility threshold at month 12 among those eligible to drive at baseline.

RESULTS

Lower proportions of study eyes experienced ≥10-, ≥15-, or ≥20-BCVA letter loss from baseline over 12 months with ACP 2 mg (11.6%, 4.0%, and 1.6%, respectively) versus sham (14.1%, 7.6%, and 4.5%, respectively). There was a reduction in the risk of persistent loss of ≥15 BCVA ETDRS letters with ACP 2 mg (3.4%) versus sham (7.8%) through 12 months. A lower proportion of study eyes treated with ACP 2 mg reached the threshold for driving ineligibility versus sham by 12 months.

CONCLUSIONS

Treatment with ACP 2 mg delayed the risk of progression to persistent vision loss (i.e., ≥10-, ≥15-, and ≥20-BCVA letter loss or BCVA loss to a level below driving eligibility threshold) versus sham over 12 months.

FINANCIAL DISCLOSURE(S)

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

AI in the clinical management of GA: A novel therapeutic universe requires novel tools

Regulatory approval of the first two therapeutic substances for the management of geographic atrophy (GA) secondary to age-related macular degeneration (AMD) is a major breakthrough following failure of numerous previous trials. However, in the absence of therapeutic standards, diagnostic tools are a key challenge as functional parameters in GA are hard to provide. The majority of anatomical biomarkers are subclinical, necessitating advanced and sensitive image analyses. In contrast to fundus autofluorescence (FAF), optical coherence tomography (OCT) provides high-resolution visualization of neurosensory layers, including photoreceptors, and other features that are beyond the scope of human expert assessment. Artificial intelligence (AI)-based methodology strongly enhances identification and quantification of clinically relevant GA-related sub-phenotypes. Introduction of OCT-based biomarker analysis provides novel insight into the pathomechanisms of disease progression and therapeutic, moving beyond the limitations of conventional descriptive assessment. Accordingly, the Food and Drug Administration (FDA) has provided a paradigm-shift in recognizing ellipsoid zone (EZ) attenuation as a primary outcome measure in GA clinical trials. In this review, the transition from previous to future GA classification and management is described. With the advent of AI tools, diagnostic and therapeutic concepts have changed substantially in monitoring and screening of GA disease. Novel technology combined with pathophysiological knowledge and understanding of the therapeutic response to GA treatments, is currently opening the path for an automated, efficient and individualized patient care with great potential to improve access to timely treatment and reduce health disparities.

Comparison of Blue-Light Autofluorescence and Ultrawidefield Green-Light Autofluorescence for Assessing Geographic Atrophy

PURPOSE

The goal of this study was to evaluate and compare the intermodality and interreader agreement of manual and semiautomated geographic atrophy (GA) area measurements in eyes with GA due to age-related macular degeneration (AMD) using conventional blue-light fundus autofluorescence (FAF) and ultrawidefield (UWF) green-light FAF systems.

DESIGN

Prospective Cohort Study.

SUBJECTS

Seventy-two eyes of 50 patients with a diagnosis of advanced nonneovascular AMD with GA.

METHODS

Fundus autofluorescence images of eyes with GA were obtained during a single visit using both the Spectralis HRA + OCT2 device and the Optos California device. The area of the GA lesion(s) was segmented and quantified (mm2) with a fully manual approach where the lesions were outlined using Optos Advance and Heidelberg Eye Explorer (HEYEX) software. In addition, for the Heidelberg blue FAF images, GA lesions were also measured using the instrument's semiautomated software (Region Finder 2.6.4). For comparison between modalities/grading method, the mean values of the 2 graders were used. Intraclass correlation coefficients were computed to judge the agreement between graders.

RESULTS

Seventy-two eyes of 50 patients were included in this study. There was nearly perfect agreement between graders for the measurement of GA area for all 3 modalities (intraclass correlation coefficient: 0.996 for manual Optos Advance, 0.996 for manual Heidelberg HEYEX, and 0.995 for Heidelberg Region Finder). The measurement of GA area was strongly correlated between modalities, with Spearman correlation coefficients of 0.985 (P < 0.001) between manual Heidelberg and manual Optos, 0.991 (P < 0.001) for Region Finder versus manual Heidelberg, and 0.985 (P < 0.001) for Region Finder versus manual Optos. The absolute mean area differences between the Heidelberg manual versus Region Finder, manual Optos versus Region Finder, and manual Optos versus manual Heidelberg were 1.61 mm2 (P < 0.001), 0.90 mm2 (P < 0.006), and 0.71 mm2 (P < 0.001), respectively.

CONCLUSIONS

We observed excellent interreader agreement for measurement of GA using either 30-degree blue-light FAF or UWF green-light FAF, establishing the reliability of UWF imaging for macular GA assessment. Although the absolute measurements between devices were strongly correlated, they differed significantly, highlighting the importance of using the same device for a given patient for the duration of a study.

FINANCIAL DISCLOSURE(S)

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;55:576-585.].

Correlation Between Blue Fundus Autofluorescence and SD-OCT Measurements of Geographic Atrophy in Dry Age-Related Macular Degeneration

PURPOSE

To compare fundus autofluorescence (FAF) and spectral domain optical coherence tomography (OCT) measurements of geographic atrophy (GA) area and to analyze lesion area changes measured by spectral domain OCT in GATHER1.

DESIGN

An assessment reliability analysis using prospective, randomized, double-masked phase 2/3 clinical trial data.

METHODS

GATHER1 examined the efficacy and safety of avacincaptad pegol (ACP) for GA treatment. A post hoc analysis was performed to identify correlations between FAF- and OCT-based measurements of GA. GA area was measured on blue-light FAF images using semiautomatic segmentation software with support from OCT and near-infrared imaging. Machine-learning enhanced, multilayer segmentation of OCT scans were reviewed by human readers, and segmentation errors were corrected as needed. GA area was defined as total RPE loss on cross-sectional B scans. Time points included Months 0, 6, 12, and 18. Additionally, OCT-based GA-area changes between ACP and sham were analyzed.

RESULTS

There was a strong correlation (r = 0.93) between FAF and OCT GA area measurements that persisted through 18 months. Mean (SD) differences between OCT and FAF GA measurements were negligible: 0.11 mm2 (1.42) at Month 0, 0.03 mm2 (1.62) at Month 6, -0.17 mm2 (1.81) at Month 12, and -0.07 mm2 (1.78) at Month 18. OCT assessments of GA growth revealed a 30% and 27% reduction at Months 12 and 18, respectively, between ACP and sham, replicating FAF measurements from GATHER1.

CONCLUSIONS

The strong correlation between blue FAF and OCT measurements of GA area supports OCT as a reliable method to measure GA lesion area in clinical trials.

Best-Corrected Visual Acuity Quantitative Prediction for Cataract Patients: AI-Assisted Clinical Diagnostics Facilitation via the Inverse Problem Algorithm

Objective: This study provided a quantitative prediction of best-corrected visual acuity (BCVA) for cataract patients using the inverse problem algorithm (IPA) technique earlier proposed by the authors. Methods: To this end, seven risk factors (age, BMI, MAP, IOP, HbA1c, LDL-C, and gender) were linked by a semi-empirical formula by normalizing each factor into a dimensionless range of -1.0 to +1.0. The adopted inverse problem algorithm (IPA) technique was run via a self-developed program in STATISTICA 7.0, featuring a 29-term nonlinear equation considering seven risk factors, cross-interaction between various pairs of factors, and one constant term [7 + (7 × 6)/2 + 1 = 29]. The IPA neglected quadratic, triple, or quadruple factors' cross-interactions. This study used a dataset of 632 cataract patients to attain a reliable BCVA prediction with a variance of 0.929. A verification dataset of 160 patients with similar symptoms was used to verify this approach's feasibility, reaching a good correlation with R2 = 0.909. Results: The verification group's derived average AT (agreement) (9.12 ± 27.00%) indicated a slight deviation between the theoretical prediction and practical BCVA. The significant factors were age, body mass index (BMI), and intraocular pressure (IOP), whereas mean arterial pressure (MAP), hemoglobin A1c (HbA1c), low-density-lipoprotein cholesterol (LDL-C), and gender insignificantly contributed to BCVA. Conclusions: The proposed approach is instrumental in AI-assisted clinical diagnosis, yielding robust BCVA predictions for individual cataract patients based on their biological indices before the ophthalmological examination procedure.

Topographic Clinical Insights From Deep Learning-Based Geographic Atrophy Progression Prediction

Purpose

To explore the contributions of fundus autofluorescence (FAF) topographic imaging features to the performance of convolutional neural network-based deep learning (DL) algorithms in predicting geographic atrophy (GA) growth rate.

Methods

Retrospective study with data from study eyes from three clinical trials (NCT02247479, NCT02247531, NCT02479386) in GA. The algorithm was initially trained with full FAF images, and its performance was considered benchmark. Ablation experiments investigated the contribution of imaging features to the performance of the algorithms. Three FAF image regions were defined relative to GA: Lesion, Rim, and Background. For No Lesion, No Rim, and No Background datasets, a single region of interest was removed at a time. For Lesion, Rim, and Background Shuffled datasets, individual region pixels were randomly shuffled. For Lesion, Rim, and Background Mask datasets, masks of the regions were used. A Convex Hull dataset was generated to evaluate the importance of lesion size. Squared Pearson correlation (r2) was used to compare the predictive performance of ablated datasets relative to the benchmark.

Results

The Rim region influenced r2 more than the other two regions in all experiments, indicating the most relevant contribution of this region to the performance of the algorithms. In addition, similar performance was observed for all regions when pixels were shuffled or only a mask was used, indicating intensity information was not independently informative without textural context.

Conclusions

These ablation experiments enabled topographic clinical insights on FAF images from a DL-based GA progression prediction algorithm.

Translational Relevance

Results from this study may lead to new insights on GA progression prediction.

Pegcetacoplan Treatment and Consensus Features of Geographic Atrophy Over 24 Months

Importance

Despite widespread availability and consensus on its advantages for detailed imaging of geographic atrophy (GA), spectral-domain optical coherence tomography (SD-OCT) might benefit from automated quantitative OCT analyses in GA diagnosis, monitoring, and reporting of its landmark clinical trials.

Objective

To analyze the association between pegcetacoplan and consensus GA SD-OCT end points.

Design, Setting, and Participants

This was a post hoc analysis of 11 614 SD-OCT volumes from 936 of the 1258 participants in 2 parallel phase 3 studies, the Study to Compare the Efficacy and Safety of Intravitreal APL-2 Therapy With Sham Injections in Patients With Geographic Atrophy (GA) Secondary to Age-Related Macular Degeneration (OAKS) and Study to Compare the Efficacy and Safety of Intravitreal APL-2 Therapy With Sham Injections in Patients With Geographic Atrophy (GA) Secondary to Age-Related Macular Degeneration (DERBY). OAKS and DERBY were 24-month, multicenter, randomized, double-masked, sham-controlled studies conducted from August 2018 to July 2020 among adults with GA with total area 2.5 to 17.5 mm2 on fundus autofluorescence imaging (if multifocal, at least 1 lesion ≥1.25 mm2). This analysis was conducted from September to December 2023.

Interventions

Study participants received pegcetacoplan, 15 mg per 0.1-mL intravitreal injection, monthly or every other month, or sham injection monthly or every other month.

Main Outcomes and Measures

The primary end point was the least squares mean change from baseline in area of retinal pigment epithelium and outer retinal atrophy in each of the 3 treatment arms (pegcetacoplan monthly, pegcetacoplan every other month, and pooled sham [sham monthly and sham every other month]) at 24 months. Feature-specific area analysis was conducted by Early Treatment Diabetic Retinopathy Study (ETDRS) regions of interest (ie, foveal, parafoveal, and perifoveal).

Results

Among 936 participants, the mean (SD) age was 78.5 (7.22) years, and 570 participants (60.9%) were female. Pegcetacoplan, but not sham treatment, was associated with reduced growth rates of SD-OCT biomarkers for GA for up to 24 months. Reductions vs sham in least squares mean (SE) change from baseline of retinal pigment epithelium and outer retinal atrophy area were detectable at every time point from 3 through 24 months (least squares mean difference vs pooled sham at month 24, pegcetacoplan monthly: -0.86 mm2; 95% CI, -1.15 to -0.57; P < .001; pegcetacoplan every other month: -0.69 mm2; 95% CI, -0.98 to -0.39; P < .001). This association was more pronounced with more frequent dosing (pegcetacoplan monthly vs pegcetacoplan every other month at month 24: -0.17 mm2; 95% CI, -0.43 to 0.08; P = .17). Stronger associations were observed in the parafoveal and perifoveal regions for both pegcetacoplan monthly and pegcetacoplan every other month.

Conclusions and Relevance

These findings offer additional insight into the potential effects of pegcetacoplan on the development of GA, including potential effects on the retinal pigment epithelium and photoreceptors.

Trial Registration

ClinicalTrials.gov Identifiers: NCT03525600 and NCT03525613.

AI-based support for optical coherence tomography in age-related macular degeneration

Artificial intelligence (AI) has emerged as a transformative technology across various fields, and its applications in the medical domain, particularly in ophthalmology, has gained significant attention. The vast amount of high-resolution image data, such as optical coherence tomography (OCT) images, has been a driving force behind AI growth in this field. Age-related macular degeneration (AMD) is one of the leading causes for blindness in the world, affecting approximately 196 million people worldwide in 2020. Multimodal imaging has been for a long time the gold standard for diagnosing patients with AMD, however, currently treatment and follow-up in routine disease management are mainly driven by OCT imaging. AI-based algorithms have by their precision, reproducibility and speed, the potential to reliably quantify biomarkers, predict disease progression and assist treatment decisions in clinical routine as well as academic studies. This review paper aims to provide a summary of the current state of AI in AMD, focusing on its applications, challenges, and prospects.

Efficacy of Subthreshold Micropulse Laser for Central Serous Chorioretinopathy

PURPOSE

To evaluate the efficacy of a subthreshold micropulse laser (SML) in patients with central serous chorioretinopathy (CSCR).

METHODS

Retrospective clinical study conducted at the Departments of Ophthalmology at a university and a municipal hospital in Zurich, Switzerland. We enrolled acute and chronic CSCR patients with persistent subretinal fluid (SRF) treated with SML. Two treatment protocols (fluorescein/indocyanine green angiography or optical coherence tomography guided) were evaluated for efficacy after 3 and 6 months. The primary outcomes of the study were reduction and percentage of eyes with complete resolution of SRF 3 and 6 months after SML treatment. Secondary endpoints included changes in central subfield thickness (CST) and visual acuity (VA) after 3 and 6 months.

RESULTS

The study involved 37 eyes (35 patients, 48.6% chronic). A statistically significant reduction in SRF height and CST could be shown, irrespective of SRF duration, type of CSCR, or chosen guidance after 3 and 6 months: SRF - 40 µm (p < 0.01), CST - 52 µm (p < 0.01). Percentage of eyes with complete resolution of fluid at 3 and 6 months after SML were 24.3 and 21.6%, respectively. No statistically significant functional improvement (VA) could be shown. Multivariable regression and linear mixed regression analyses did not identify statistically significant differences in SRF reduction, CMT change, or VA improvement with respect to the type of CSCR or the treatment plan used (p > 0.05).

CONCLUSION

The effectiveness of SML in CSCR is under continuous debate. Our study findings demonstrate structural but only little functional changes with SML. In view of the shortage of verteporfin for photodynamic therapy, SML remains an important therapeutic option for CSCR patients.

Inter and intradevice assessment of microperimetry testing in aging eyes

Microperimetry (MP) is a psychometric examination combining retinal imaging and functional sensitivity testing with an increasing importance due to its potential use as clinical study outcome. We investigated the repeatability of pointwise retinal sensitivity (PWS) on the most advanced commercially available MP devices under their standard setting in a healthy aging population. Two successive MP examinations on both MP-3 (NIDEK CO., Ltd., Gamagori, Japan) and MAIA (CenterVue S.p.A. (iCare), Padova, Italy) were performed on healthy aging subjects in a randomized order. PWS repeatability was analysed for different macular regions and age groups using Bland-Altmann coefficients of repeatability (CoR). A total of 3600 stimuli from 20 healthy individuals with a mean age of 70 (11) years were included. Mean CoR in dB were ±4.61 for MAIA and ±4.55 for MP-3 examinations. A lower repeatability (p=0.005) was detected in the central millimetre on MAIA examinations. Higher subject age was associated with a lower repeatability of PWS on both devices (both p=0.003). Intra-device correlation was good (MAIA: 0.79 [0.76-0.81]; MP-3: 0.72 [0.68-0.76]) whereas a moderate mean inter-device correlation (0.6 [0.55-0.65]) could be detected. In conclusion, older subjects and the foveal region are associated with a worse pointwise repeatability.

Macular Sensitivity Endpoints in Geographic Atrophy: Exploratory Analysis of Chroma and Spectri Clinical Trials

Purpose

To assess different microperimetry (MP) macular sensitivity outcome measures capturing functional deterioration in eyes with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).

Design

Patients were included from 2 identically designed, phase III, double-masked, randomized controlled clinical trials, Chroma (NCT02247479) and Spectri (NCT02247531).

Participants

Patients enrolled were aged ≥ 50 years with bilateral GA and no evidence of previous or active neovascular AMD.

Methods

Patients were randomized 2:1:2:1 to receive through 96 weeks intravitreal lampalizumab 10 mg every 4 weeks (LQ4W), every 6 weeks (LQ6W), or corresponding sham procedures. For this study, mesopic macular sensitivity of the central 20° was assessed using MP-1 microperimeter at selected sites.

Main Outcome Measures

Two exploratory endpoints were developed, namely perilesional sensitivity (average of points adjacent to absolute scotomatous points) and responding sensitivity (average of all nonscotomatous points; > 0 dB at baseline) by using customized masks for each patient. These were compared with conventional MP endpoints (mean macular sensitivity and number of absolute scotomatous points).

Results

Of 1881 Chroma and Spectri participants, 277 agreed to participate in the present study. Of these, 197 (LQ4W, n = 63; LQ6W, n = 68; pooled sham, n = 66) had reliable MP results. Enlargement of GA lesion area by approximately 2 mm2/year across treatment groups was accompanied by deterioration in all MP parameters. There was no difference in worsening of macular sensitivity or absolute scotomatous points among treatment groups. Perilesional and responding sensitivities showed greater decline over time than mean macular sensitivity. Change in GA lesion area at week 48 showed better correlation with perilesional sensitivity (r = -0.17) and responding sensitivity (r = -0.20) than mean macular sensitivity (r = -0.03), while the correlation was highest with the number of absolute scotomatous points (r = 0.37).

Conclusions

Perilesional or responding macular sensitivity measured by MP should be considered more sensitive endpoints than mean macular sensitivity for monitoring functional decline over time in GA. Although perilesional, responding, and mean macular sensitivity had weak correlation with GA lesion area, the number of absolute scotomatous points may provide additional information on the anatomic/functional correlation.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Geographic atrophy: pathophysiology and current therapeutic strategies

Geographic atrophy (GA) is an advanced stage of age-related macular degeneration (AMD) that leads to gradual and permanent vision loss. GA is characterized by the loss of photoreceptor cells and retinal pigment epithelium (RPE), leading to distinct atrophic patches in the macula, which tends to increase with time. Patients with geographic atrophy often experience a gradual and painless loss of central vision, resulting in difficulty reading, recognizing faces, or performing activities that require detailed vision. The primary risk factor for the development of geographic atrophy is advanced age; however, other risk factors, such as family history, smoking, and certain genetic variations, are also associated with AMD. Diagnosis is usually based on a comprehensive eye examination, including imaging tests such as fundus photography, optical coherence tomography (OCT), and fluorescein angiography. Numerous clinical trials are underway, targeting identified molecular pathways associated with GA that are promising. Recent approvals of Syfovre and Izervay by the FDA for the treatment of GA provide hope to affected patients. Administration of these drugs resulted in slowing the rate of progression of the disease. Though these products provide treatment benefits to the patients, they do not offer a cure for geographic atrophy and are limited in efficacy. Considering these safety concerns and limited treatment benefits, there is still a significant need for therapeutics with improved efficacy, safety profiles, and better patient compliance. This comprehensive review discusses pathophysiology, currently approved products, their limitations, and potential future treatment strategies for GA.

Geographic atrophy - Signs, symptoms, and quality of life

Geographic atrophy (GA) is a prevalent cause of vision loss among elderly and is associated with a significant loss of function. We reviewed the current literature to assess the effect of GA on patients' daily lives and well-being. We record and organize the signs, symptoms, and impacts that are important in life with GA. Further, we examined the impact of GA on vision-related quality of life. The main complaint among patients was difficulties regarding daily tasks, especially reading and other near activities. However, a large proportion of patients also reported fear, frustration, and anxiety as salient symptoms with large impact. Many patients do not have adequate information about their condition as well as the prognosis. The most commonly used measure of patient-reported outcome measure (PROM) is the National Eye Institute Visual Function Questionnaire (VFQ), that reflects the severity of impact on 12 subscales, from where near activities, general vision, mental health, and role difficulties had the lowest scores. Longitudinal studies of GA and the impact of low-vision rehabilitation efforts on health-related quality of life are sparse but suggest a significant improvement on several items. PROM is included in clinical trials, and so far, no drug has shown to improve the functional outcome in terms of PROM.

An Evaluation of the Repeatability of Visual Function Following Surgical Repair of Macula-Off Rhegmatogenous Retinal Detachment

Purpose

To evaluate the reliability and reproducibility of visual function assessments for patients with macula-off rhegmatogenous retinal detachment (RRD).

Methods

This prospective study included patients with unilateral macula-off RRD of <10-day duration successfully treated with a single, uncomplicated surgery at least 1 year following repair. Visual function assessments were performed at time of enrollment and 1 month later. Testing included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), low-contrast visual acuity (VA) 2.5% and 5%, contrast sensitivity assessment with Mars and Gabor patches, reading speed (acuity, speed, and critical print size), color vision testing (protan, deutan, and tritan), and microperimetry. Spectral-domain ocular coherence tomography (SD-OCT) was performed. Paired t-statistics were used to compare values between visits and between the study and fellow eyes.

Results

Fourteen patients (9 male, 5 female) with a mean age of 69 years at time of surgery were evaluated. Correlation coefficients across the two visits were highest for ETDRS BCVA (0.97), tritan color vision testing (0.96), and low-contrast VA 5% (0.96), while the average t-statistic was largest for low-luminance deficit (4.2), ETDRS BCVA (4.1), and reading speed critical print size (3.7). ETDRS BCVA did not correlate with SD-OCT findings.

Conclusions

ETDRS BCVA can be considered a highly reliable and reproducible outcome measure. LLVA, protan color discrimination, contrast sensitivity, and reading speed may be useful secondary outcome measures.

Translational Relevance

This study provides guidance on the selection of visual function outcome measures for clinical trials of patients with macula-off RRD.

A Deep-Learning Algorithm to Predict Short-Term Progression to Geographic Atrophy on Spectral-Domain Optical Coherence Tomography

Importance

The identification of patients at risk of progressing from intermediate age-related macular degeneration (iAMD) to geographic atrophy (GA) is essential for clinical trials aimed at preventing disease progression. DeepGAze is a fully automated and accurate convolutional neural network-based deep learning algorithm for predicting progression from iAMD to GA within 1 year from spectral-domain optical coherence tomography (SD-OCT) scans.

Objective

To develop a deep-learning algorithm based on volumetric SD-OCT scans to predict the progression from iAMD to GA during the year following the scan.

Design, Setting, and Participants

This retrospective cohort study included participants with iAMD at baseline and who either progressed or did not progress to GA within the subsequent 13 months. Participants were included from centers in 4 US states. Data set 1 included patients from the Age-Related Eye Disease Study 2 AREDS2 (Ancillary Spectral-Domain Optical Coherence Tomography) A2A study (July 2008 to August 2015). Data sets 2 and 3 included patients with imaging taken in routine clinical care at a tertiary referral center and associated satellites between January 2013 and January 2023. The stored imaging data were retrieved for the purpose of this study from July 1, 2022, to February 1, 2023. Data were analyzed from May 2021 to July 2023.

Exposure

A position-aware convolutional neural network with proactive pseudointervention was trained and cross-validated on Bioptigen SD-OCT volumes (data set 1) and validated on 2 external data sets comprising Heidelberg Spectralis SD-OCT scans (data sets 2 and 3).

Main Outcomes and Measures

Prediction of progression to GA within 13 months was evaluated with area under the receiver-operator characteristic curves (AUROC) as well as area under the precision-recall curve (AUPRC), sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.

Results

The study included a total of 417 patients: 316 in data set 1 (mean [SD] age, 74 [8]; 185 [59%] female), 53 in data set 2, (mean [SD] age, 83 [8]; 32 [60%] female), and 48 in data set 3 (mean [SD] age, 81 [8]; 32 [67%] female). The AUROC for prediction of progression from iAMD to GA within 1 year was 0.94 (95% CI, 0.92-0.95; AUPRC, 0.90 [95% CI, 0.85-0.95]; sensitivity, 0.88 [95% CI, 0.84-0.92]; specificity, 0.90 [95% CI, 0.87-0.92]) for data set 1. The addition of expert-annotated SD-OCT features to the model resulted in no improvement compared to the fully autonomous model (AUROC, 0.95; 95% CI, 0.92-0.95; P = .19). On an independent validation data set (data set 2), the model predicted progression to GA with an AUROC of 0.94 (95% CI, 0.91-0.96; AUPRC, 0.92 [0.89-0.94]; sensitivity, 0.91 [95% CI, 0.74-0.98]; specificity, 0.80 [95% CI, 0.63-0.91]). At a high-specificity operating point, simulated clinical trial recruitment was enriched for patients progressing to GA within 1 year by 8.3- to 20.7-fold (data sets 2 and 3).

Conclusions and Relevance

The fully automated, position-aware deep-learning algorithm assessed in this study successfully predicted progression from iAMD to GA over a clinically meaningful time frame. The ability to predict imminent GA progression could facilitate clinical trials aimed at preventing the condition and could guide clinical decision-making regarding screening frequency or treatment initiation.

Impact of Prophylactic Ranibizumab to Prevent Neovascular Age-Related Macular Degeneration on Eyes With Intermediate Age-Related Macular Degeneration

Purpose

The purpose of this study was to determine the impact of prophylactic ranibizumab (PR) injections given every 3 months in eyes with intermediate nonexudative age-related macular degeneration (AMD) on drusen volume, macular layer thicknesses, and progression of geographic atrophy (GA) area over 24 months in the PREVENT trial.

Methods

This post hoc analysis of the prospective PREVENT trial compared eyes with intermediate AMD randomized to PR versus sham injections to determine rates of conversion to neovascular AMD over 24 months. Drusen area and volume, macular thickness and volume, and retinal layer thicknesses were measured on spectral-domain optical coherence tomography images and analyzed. Masked grading of GA area and subretinal drusenoid deposits (SDDs) using fundus autofluorescence images was performed.

Results

There were no statistical differences in drusen area and volumes between groups, and similar reductions in central subfield thickness, mean cube thickness, cube volume, and retinal sublayer thickness from baseline to 24 months (P = 0.018 to < 0.001), with no statistical differences between groups in any of these anatomic parameters. These findings were not impacted by the presence or absence of SDD. Among the 9 eyes with GA in this study, mean GA growth rate from baseline to 24 months was 1.34 +/- 0.79 mm2/year after PR and 1.95 +/- 1.73 mm2/year in sham-treated eyes (P = 0.49), and similarly showed no statistical difference with square root transformation (P = 0.61).

Conclusions

Prophylactic ranibizumab given every 3 months did not appear to affect drusen volume, macular thinning, or GA progression in eyes with intermediate AMD.

Translational Relevance

This work investigates the impact of PR on progressive retinal degeneration in a clinical trial.

The impact of early RPE cell junction loss on VEGF, Ang-2, and TIMP secretion in vitro

Purpose

The retinal pigment epithelium (RPE) is an important tissue for maintaining a healthy retina. Retinal pigment epithelial cells help regulate nutrient transport to photoreceptors and are heavily pigmented to prevent light scattering. These cells also have junction proteins to form monolayers. Monolayers are key players in pathologies such as age-related macular degeneration (AMD), a leading cause of vision loss in older adults. During AMD, RPE cell detachment can occur, resulting in a loss of junctions. Losing junctions can increase the expression of pro-angiogenic vascular endothelial growth factor (VEGF). This overexpression can cause abnormal blood vessel growth or angiogenesis in the retina. Age-related macular degeneration treatments target VEGF to slow angiogenesis progression. However, other proteins, such as angiopoietin-2 (Ang-2) and the tissue inhibitor of metalloproteinase-1 (TIMP-1), may also play important roles, making them potential targets for treatment. Controlling RPE junction formation will help elucidate the relationship between RPE cell detachment and additional angiogenic factor secretion, lead to more therapeutics, and increase the efficacy of current treatments.

Methods

Micropatterning was used to control the spatial arrangement of primary porcine RPE cells using polydimethylsiloxane (PDMS) stencils. Patterns were formed into PDMS stencils to mimic 10%, 25%, and 50% overall detachment of the RPE monolayer. Zonula-occludens-1 (ZO-1), Ang-2, and VEGF were visualized using immunocytochemical (ICC) staining. An enzyme-linked immunosorbent assay (ELISA) was used to quantify extracellular Ang-2, VEGF, TIMP-1, and TIMP-2 levels. A rod outer segment (OS) phagocytosis assay was performed to determine how RPE junction loss directly affects photoreceptor support.

Results

The growth of primary porcine RPE cells was successfully controlled using stencils. Morphological changes and a decrease in pigmentation were observed, showing a decline in barrier and light absorption functions as degeneration increased. One day after stencil removal, junction proteins were delocalized, and angiogenic factor secretions were correlated with increased levels of detachment. Secretion levels of Ang-2 and TIMP-1 were significantly increased, whereas VEGF and TIMP-2 concentrations were not as affected by varying levels of detachment. OS phagocytosis appeared lower in RPE cells when ZO-1 was affected.

Conclusions

These results suggest a correlation between loss of junctions, abnormal angiogenic protein secretion, and reduced OS phagocytosis. Furthermore, Ang-2 and TIMP-1 proteins might be beneficial targets for AMD treatments, and their roles in retinal diseases deserve further investigation.

Geographic Atrophy Segmentation Using Multimodal Deep Learning

Purpose

To examine deep learning (DL)-based methods for accurate segmentation of geographic atrophy (GA) lesions using fundus autofluorescence (FAF) and near-infrared (NIR) images.

Methods

This retrospective analysis utilized imaging data from study eyes of patients enrolled in Proxima A and B (NCT02479386; NCT02399072) natural history studies of GA. Two multimodal DL networks (UNet and YNet) were used to automatically segment GA lesions on FAF; segmentation accuracy was compared with annotations by experienced graders. The training data set comprised 940 image pairs (FAF and NIR) from 183 patients in Proxima B; the test data set comprised 497 image pairs from 154 patients in Proxima A. Dice coefficient scores, Bland-Altman plots, and Pearson correlation coefficient (r) were used to assess performance.

Results

On the test set, Dice scores for the DL network to grader comparison ranged from 0.89 to 0.92 for screening visit; Dice score between graders was 0.94. GA lesion area correlations (r) for YNet versus grader, UNet versus grader, and between graders were 0.981, 0.959, and 0.995, respectively. Longitudinal GA lesion area enlargement correlations (r) for screening to 12 months (n = 53) were lower (0.741, 0.622, and 0.890, respectively) compared with the cross-sectional results at screening. Longitudinal correlations (r) from screening to 6 months (n = 77) were even lower (0.294, 0.248, and 0.686, respectively).

Conclusions

Multimodal DL networks to segment GA lesions can produce accurate results comparable with expert graders.

Translational Relevance

DL-based tools may support efficient and individualized assessment of patients with GA in clinical research and practice.

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.

Geographic Atrophy in AMD: Prognostic Factors Based on Long-Term Follow-Up

INTRODUCTION

The aim of this large-scale long-term retrospective study was to show the enlargement rate (ER) of geographic atrophy (GA) in age-related macular degeneration (AMD), defined as complete retinal pigment epithelium and outer retinal atrophy (cRORA), to find predictors of progression in a clinical routine setting and to compare GA evaluation methods.

METHODS

All patients available in our database with follow-up of at least 24 months and cRORA in at least one eye, regardless of neovascular AMD being present, were included. SD-OCT and fundus autofluorescence (FAF) evaluations were performed according to a standardized protocol. The cRORA area ER, the cRORA square root area ER, the FAF GA area, and the condition of the outer retina (inner-/outer-segment [IS/OS] line and external limiting membrane [ELM] disruption scores) were determined.

RESULTS

204 eyes of 129 patients were included. Mean follow-up time was 4.2 ± 2.2 (range 2-10) years. 109 of 204 (53.4%) eyes were classified as MNV-associated GA in AMD (initially or during follow-up); 95 of 204 (46.6%) eyes were classified as pure GA in AMD. The primary lesion was unifocal in 146 (72%) eyes and multifocal in 58 (28%) eyes. A strong correlation was observed between the area of cRORA (SD-OCT) and the FAF GA area (r = 0.924; p < 0.001). Mean ER was 1.44 ± 1.2 mm2/year, mean square root ER 0.29 ± 0.19 mm/year. There was no significant difference in mean ER between eyes without (pure GA) and with intravitreal anti-VEGF injections (MNV-associated GA) (0.30 ± 0.19 mm/year vs. 0.28 ± 0.20 mm/year; p = 0.466). Eyes with multifocal atrophy pattern at baseline had a significantly higher mean ER compared to eyes with unifocal pattern (0.34 ± 0.19 mm/year vs. 0.27 ± 1.19 mm/year; p = 0.008). There were moderate significant correlations between ELM and IS/OS disruption scores and visual acuity at baseline, 5 and 7 years (all r values ca. -0.5; p < 0.001). In multivariate regression analysis, a multifocal cRORA pattern at baseline (p = 0.022) and a smaller baseline lesion size (p = 0.036) were associated with a higher mean ER.

CONCLUSION

SD-OCT-evaluated cRORA area might serve as a GA parameter comparable to traditional FAF measurement in clinical routine. The dispersion pattern and baseline lesion size might be predictors of ER, whereas anti-VEGF treatment seems not to be associated with ER.

Geographic atrophy: Mechanism of disease, pathophysiology, and role of the complement system

Geographic atrophy (GA) is an advanced form of age-related macular degeneration (AMD), characterized by atrophic lesions that first start in the outer retina and progressively expand to cover the macula and the fovea, the center of the macula, leading to irreversible loss of vision over time. GA is distinct from wet or neovascular AMD (nAMD), the other form of advanced AMD. Neovascular AMD is characterized by new invading leaky blood vessels in the macula that can lead to acute vision loss. GA and nAMD may coexist in the same eye. The underlying pathophysiology of GA is complex and thought to involve chronic inflammation due to overactivation of the complement system that leads to the loss of photoreceptors, retinal pigment epithelium (RPE), and the underlying choriocapillaris. The disappearance of these structures appears as sharply demarcated atrophic lesions that are typical of GA. Researchers have reported about 1 million reported cases of GA in the United States, and about 160,000 cases occur per year. The most important risk factors for GA are increasing age and family history. Diagnosis of GA is usually made by using multimodal imaging techniques. Lesions associated with GA are highly heterogeneous, and the growth rate may differ from patient to patient. Despite the progressive nature of GA, the fovea may be spared until much later in the disease, thereby retaining central vision in patients. With time, atrophic lesions may progressively grow to involve the fovea, thereby severely impairing central vision. Vision loss can happen rapidly once the lesions reach the fovea. However, even without the involvement of the fovea, ongoing vision impairment impacting daily life may be present. Median time from GA not involving the center of the fovea (without subfoveal involvement) to GA with lesion boundary affecting the foveal center (subfoveal involvement) ranges from 1.4 to 2.5 years. GA can greatly impact patients' functioning and quality of life and limit their independence by interfering with activities of daily living, including difficulties with reading, driving, watching television, recognizing faces, and being unable to do household chores. No treatments have been available until intravitreal pegcetacoplan was recently approved by the US Food and Drug Administration for GA secondary to AMD. DISCLOSURES: Dr Bakri serves as a consultant to Apellis Pharmaceuticals, as well as AbbVie, Adverum, Eyepoint, iLumen, Iveric Bio, Genentech, Novartis, Outlook Therapeutics, Pixium, Regeneron, Roche, and Regenxbio. Drs Sharp, Luo, and Sarda are employees of Apellis Pharmaceuticals. Dr Bektas and Ms Khan are employees of RTI Health Solutions. Apellis developed and led the concept design of this publication, review and interpretation, approval, and decision to publish. This research was developed under a research contract between RTI Health Solutions and Apellis Pharmaceuticals and was funded by Apellis Pharmaceuticals. This supplement is to describe the disease of geographic atrophy and was funded by Apellis. Apellis Pharmaceuticals has developed Syfovre (pegcetacoplan), the first and only treatment for geographic atrophy.

Clinical validation for automated geographic atrophy monitoring on OCT under complement inhibitory treatment

Geographic atrophy (GA) represents a late stage of age-related macular degeneration, which leads to irreversible vision loss. With the first successful therapeutic approach, namely complement inhibition, huge numbers of patients will have to be monitored regularly. Given these perspectives, a strong need for automated GA segmentation has evolved. The main purpose of this study was the clinical validation of an artificial intelligence (AI)-based algorithm to segment a topographic 2D GA area on a 3D optical coherence tomography (OCT) volume, and to evaluate its potential for AI-based monitoring of GA progression under complement-targeted treatment. 100 GA patients from routine clinical care at the Medical University of Vienna for internal validation and 113 patients from the FILLY phase 2 clinical trial for external validation were included. Mean Dice Similarity Coefficient (DSC) was 0.86 ± 0.12 and 0.91 ± 0.05 for total GA area on the internal and external validation, respectively. Mean DSC for the GA growth area at month 12 on the external test set was 0.46 ± 0.16. Importantly, the automated segmentation by the algorithm corresponded to the outcome of the original FILLY trial measured manually on fundus autofluorescence. The proposed AI approach can reliably segment GA area on OCT with high accuracy. The availability of such tools represents an important step towards AI-based monitoring of GA progression under treatment on OCT for clinical management as well as regulatory trials.

Randomized Phase 2b Study of Brimonidine Drug Delivery System Generation 2 for Geographic Atrophy in Age-related Macular Degeneration

PURPOSE

To evaluate the safety and efficacy of repeat injections of Brimonidine Drug Delivery System (Brimo DDS) Generation 2 (Gen 2) containing 400 μg brimonidine in patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).

DESIGN

Phase 2b, randomized, multicenter, double-masked, sham-controlled, 30-month study (BEACON).

PARTICIPANTS

Patients diagnosed with GA secondary to AMD and multifocal lesions with total area >1.25 mm² and ≤18 mm² in the study eye.

METHODS

Enrolled patients were randomized to treatment with intravitreal injections of 400-μg Brimo DDS (n=154) or sham procedure (n=156) in the study eye every 3 months from day 1 through month 21.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was change from baseline in the GA lesion area in the study eye, assessed with fundus autofluorescence imaging, at month 24. Safety measures included treatment-emergent adverse events (AEs).

RESULTS

The study was terminated early, at the time of the planned interim analysis, because of a slow GA progression rate (∼1.6 mm²/year) in the enrolled population. Least-squares mean (standard error) GA area change from baseline at month 24 (primary endpoint) was 3.24 (0.13) mm² with Brimo DDS (n=84) versus 3.48 (0.13) mm² with sham (n=91); the reduction in GA area change from baseline in the Brimo DDS group compared with the sham group was 0.25 mm² (7%) (P = 0.150). At month 30, the GA area change from baseline was 4.09 (0.15) mm² with Brimo DDS (n=49) versus 4.52 (0.15) mm² with sham (n=46), a reduction of 0.43 mm² (10%) with Brimo DDS compared with sham (P=0.033). Exploratory analysis showed numerically smaller loss over time in retinal sensitivity assessed with scotopic microperimetry with Brimo DDS compared with sham (P=0.053 at month 24). Treatment-related AEs were usually related to the injection procedure. No implant accumulation was observed.

CONCLUSIONS

Multiple intravitreal administrations of Brimo DDS (Gen 2) were well tolerated. The primary efficacy endpoint at 24 months was not met, but there was a numerical trend for reduction in GA progression at 24 months compared with sham treatment. The study was terminated early because of the lower-than-expected GA progression rate in the sham/control group.

A Deep Learning Model for Automated Segmentation of Geographic Atrophy Imaged Using Swept-Source OCT

PURPOSE

To present a deep learning algorithm for segmentation of geographic atrophy (GA) using en face swept-source OCT (SS-OCT) images that is accurate and reproducible for the assessment of GA growth over time.

DESIGN

Retrospective review of images obtained as part of a prospective natural history study.

SUBJECTS

Patients with GA (n = 90), patients with early or intermediate age-related macular degeneration (n = 32), and healthy controls (n = 16).

METHODS

An automated algorithm using scan volume data to generate 3 image inputs characterizing the main OCT features of GA-hypertransmission in subretinal pigment epithelium (sub-RPE) slab, regions of RPE loss, and loss of retinal thickness-was trained using 126 images (93 with GA and 33 without GA, from the same number of eyes) using a fivefold cross-validation method and data augmentation techniques. It was tested in an independent set of one hundred eighty 6 × 6-mm² macular SS-OCT scans consisting of 3 repeated scans of 30 eyes with GA at baseline and follow-up as well as 45 images obtained from 42 eyes without GA.

MAIN OUTCOME MEASURES

The GA area, enlargement rate of GA area, square root of GA area, and square root of the enlargement rate of GA area measurements were calculated using the automated algorithm and compared with ground truth calculations performed by 2 manual graders. The repeatability of these measurements was determined using intraclass coefficients (ICCs).

RESULTS

There were no significant differences in the GA areas, enlargement rates of GA area, square roots of GA area, and square roots of the enlargement rates of GA area between the graders and the automated algorithm. The algorithm showed high repeatability, with ICCs of 0.99 and 0.94 for the GA area measurements and the enlargement rates of GA area, respectively. The repeatability limit for the GA area measurements made by grader 1, grader 2, and the automated algorithm was 0.28, 0.33, and 0.92 mm², respectively.

CONCLUSIONS

When compared with manual methods, this proposed deep learning-based automated algorithm for GA segmentation using en face SS-OCT images was able to accurately delineate GA and produce reproducible measurements of the enlargement rates of GA.

Automated Identification of Incomplete and Complete Retinal Epithelial Pigment and Outer Retinal Atrophy Using Machine Learning

OBJECTIVE

To assess and validate a deep learning algorithm to automatically detect incomplete retinal pigment epithelial and outer retinal atrophy (iRORA) and complete retinal pigment epithelial and outer retinal atrophy (cRORA) in eyes with age-related macular degeneration.

DESIGN

In a retrospective machine learning analysis, a deep learning model was trained to jointly classify the presence of iRORA and cRORA within a given B-scan. The algorithm was evaluated using 2 separate and independent datasets.

PARTICIPANTS

OCT B-scan volumes from 71 patients with nonneovascular age-related macular degeneration captured at the Doheny-University of California Los Angeles Eye Centers and the following 2 external OCT B-scans testing datasets: (1) University of Pennsylvania, University of Miami, and Case Western Reserve University and (2) Doheny Image Reading Research Laboratory.

METHODS

The images were annotated by an experienced grader for the presence of iRORA and cRORA. A Resnet18 model was trained to classify these annotations for each B-scan using OCT volumes collected at the Doheny-University of California Los Angeles Eye Centers. The model was applied to 2 testing datasets to assess out-of-sample model performance.

MAIN OUTCOMES MEASURES

Model performance was quantified in terms of area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC). Sensitivity, specificity, and positive predictive value were also compared against additional clinician annotators.

RESULTS

On an independently collected test set, consisting of 1117 volumes from the general population, the model predicted iRORA and cRORA presence within the entire volume with nearly perfect AUROC performance and AUPRC scores (iRORA, 0.61; 95% confidence interval [CI] [0.45, 0.82]: cRORA, 0.83; 95% CI [0.68, 0.95]). On another independently collected set, consisting of 60 OCT B-scans enriched for iRORA and cRORA lesions, the model performed with AUROC (iRORA: 0.68, 95% CI [0.54, 0.81]; cRORA: 0.84, 95% CI [0.75, 0.94]) and AUPRC (iRORA: 0.70, 95% CI [0.55, 0.86]; cRORA: 0.82, 95% CI [0.70, 0.93]).

CONCLUSIONS

A deep learning model can accurately and precisely identify both iRORA and cRORA lesions within the OCT B-scan volume. The model can achieve similar sensitivity compared with human graders, which potentially obviates a laborious and time-consuming annotation process and could be developed into a diagnostic screening tool.

Comparison of Fundus Autofluorescence Versus Optical Coherence Tomography-based Evaluation of the Therapeutic Response to Pegcetacoplan in Geographic Atrophy

PURPOSE

To perform an optical coherence tomography (OCT)-based analysis of geographic atrophy (GA) progression in patients treated with pegcetacoplan.

DESIGN

Post hoc analysis of a phase 2 multicenter, randomized, sham-controlled trial.

METHODS

Manual annotation of retinal pigment epithelium (RPE), ellipsoid zone (EZ), and external limiting membrane (ELM) loss was performed on OCT volumes from baseline and month 12 from the phase 2 FILLY trial of intravitreal pegcetacoplan for the treatment of GA secondary to age-related macular degeneration.

MAIN OUTCOME MEASURES

Correlation of GA areas measured on fundus autofluorescence and OCT. Difference in square root transformed growth rates of RPE, EZ, and ELM loss between treatment groups (monthly injection [AM], injection every other month [AEOM], and sham [SM]).

RESULTS

OCT volumes from 113 eyes of 113 patients (38 AM, 36 AEOM, and 39 SM) were included, resulting in 11 074 B-scans. The median growth of RPE loss was significantly slower in the AM group (0.158 [0.057-0.296]) than the SM group (0.255 [0.188-0.359], P = .014). Importantly, the growth of EZ loss was also significantly slower in the AM group (0.127 [0.041-0.247]) than the SM group (0.232 [0.130-0.349], P = .017). There was no significant difference in the growth of ELM loss between the treatment groups (P = .114).

CONCLUSIONS

OCT imaging provided consistent results for GA growth compared with fundus autofluorescence. In addition to slower RPE atrophy progression in patients treated with pegcetacoplan, a significant reduction in EZ impairment was also identified by OCT, suggesting the use of OCT as a potentially more sensitive monitoring tool in GA therapy.

Fundus autofluorescence and optical coherence tomography biomarkers associated with the progression of geographic atrophy secondary to age-related macular degeneration

OBJECTIVES

To investigate the impact of qualitatively graded and deep learning quantified imaging biomarkers on growth of geographic atrophy (GA) secondary to age-related macular degeneration.

METHODS

This prospective study included 1062 visits of 181 eyes of 100 patients with GA. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) images were acquired at each visit. Hyperreflective foci (HRF) were quantitatively assessed in SD-OCT volumes using a validated deep learning algorithm. FAF images were graded for FAF patterns, subretinal drusenoid deposits (SDD), GA lesion configuration and atrophy enlargement. Linear mixed models were calculated to investigate associations between all parameters and GA progression.

RESULTS

FAF patterns were significantly associated with GA progression (p < 0.001). SDD was associated with faster GA growth (p = 0.005). Eyes with higher HRF concentrations showed a trend towards faster GA progression (p = 0.072) and revealed a significant impact on GA enlargement in interaction with FAF patterns (p = 0.01). The fellow eye status had no significant effect on lesion enlargement (p > 0.05). The diffuse-trickling FAF pattern exhibited significantly higher HRF concentrations than any other pattern (p < 0.001).

CONCLUSION

Among a wide range of investigated biomarkers, SDD and FAF patterns, particularly in interaction with HRF, significantly impact GA progression. Fully automated quantification of retinal imaging biomarkers such as HRF is both reliable and merited as HRF are indicators of retinal pigment epithelium dysmorphia, a central pathogenetic mechanism in GA. Identifying disease markers using the combination of FAF and SD-OCT is of high prognostic value and facilitates individualized patient management in a clinical setting.

Compass Fundus-Guided Perimetry in Geographic Atrophy

Purpose

To evaluate compass (CMP), a recently introduced device that combines scanning ophthalmoscopy, automated perimetry, and eye tracking, for fundus-guided perimetry (microperimetry) with the purpose of correlating perimetric retinal sensitivity (PRS) and retinal geographic atrophy (GA) features.

Materials and Methods

A retrospective, cross-sectional study was performed in 56 eyes of 43 patients affected by GA. All patients underwent compass 10-2 perimetry, consisting of a full-threshold visual field on fundus photography and an infrared (IR) image of the central 30° of the retina. Data were exported to an Excel sheet. Binarization with black/white (B/W) variables was applied on the compass photo fundus and matched with visual field scores. Patients underwent autofluorescence (AF) and IR images (Heidelberg, Germany): CMP and Heidelberg IR images were homologated by using GIMP software (https://www.gimp.org), and then atrophic areas were manually measured with the ImageJ program. CMP perimetric grid was overlapped with AF and IR pictures by using GIMP, obtaining composite TIFF images, which were then analyzed with the ImageJ greyscale score (GSS) tool. A hyperautofluorescent halo was identified on the GA edges of some patients. Pearson's correlation between GA size on IR compass and IR Heidelberg and between GSS and PRS values has been calculated; the independent t-test was realized to calculate the correlation between GSS and B/W variables identified on the CMP photo fundus. The Spearman correlation between total deviation and pattern deviation was calculated.

Results

The AUC-ROC score between CMP scores and B/W variables was 93,4%. The Spearman correlation between total deviation and pattern deviation was highly significant (p = 0,00). The correlation between AF GSS values and PRS was significant (p value = 0,00), the correlation between GSS of hyperautofluorescent points and PRS was significant (p value = 0,00), and the correlation between IR GSS and PRS was significant (p value = 0,00). The correlation between AF GSS and B/W variables was significant (p value = 0,002), the correlation between hyperautofluorescent points and B/W was not significant (p value = 0,40), and the correlation between IR GSS and B/W was significant (p = 0,00).

Conclusions

Based on our preliminary results, compass seems to be a reliable, quick, and safe device for the anatomical and functional study of GA. The direct visualization of the visual field on the fundus photography as a background allows a precise assessment and clinical monitoring of this disease.

The role of dual antiplatelets in geographic atrophy secondary to non-neovascular aged-related macular degeneration

Background

To evaluate the effects of dual antiplatelets on progression of geographic atrophy (GA) secondary to age-related macular degeneration (AMD), and to determine additional factors predicting rapid GA growth.

Material and Methods

In this retrospective cohort study, patients with unifocal GA were consecutively enrolled (one eye per patient) from 2018 to 2021. The patients were categorized as 1. those receiving dual antiplatelet therapy containing a daily dose of 75 mg clopidogrel plus 81 mg aspirin (DAPT group), and 2. those not receiving DAPT (control group). Areas of GA, based on red-filtered fundus autofluorescence, were measured at baseline, and at 3, 6, and 12 months. The primary outcome was absolute 12-month changes in the square root (SQRT) area.

Results

One eye in each group developed neovascular AMD and was excluded from the analysis. The DAPT (24 eyes) and control (22 eyes) groups had comparable age and baseline SQRT area (1.2 ± 0.27 and 1.8 ± 0.41 mm, respectively; p adjusted for age = 0.23). At 12 months, after controlling for age and the presence of soft drusen or reticular pseudodrusen, patients receiving DAPT had fewer changes in the SQRT area than that of the control group (0.097 vs. 0.17 mm; p = 0.02). The presence of drusen significantly predicted increased GA growth and choroidal thickness reduction.

Conclusions

Routine uses of dual antiplatelets were associated with decelerating GA growth. Drusen-associated GA may represent a generalized form of choroidal vascular alterations.

The effect of pegcetacoplan treatment on photoreceptor maintenance in geographic atrophy monitored by AI-based OCT analysis

PURPOSE

To investigate the therapeutic effect of intravitreal pegcetacoplan on the inhibition of photoreceptor (PR) loss and thinning in geographic atrophy (GA) on conventional spectral domain-optical coherence tomography (SD-OCT) imaging by deep learning-based automated PR quantification.

DESIGN

Post-hoc analysis of a prospective, multicenter, randomized, sham-controlled, masked phase II trial investigating the safety and efficacy of pegcetacoplan for the treatment of GA due to age-related macular degeneration.

PARTICIPANTS

Study eyes of 246 patients, randomized 1:1:1 to monthly (AM), bimonthly (AEOM) and sham (SM) treatment.

METHODS

We performed fully automated, deep learning-based segmentation of retinal pigment epithelium (RPE) loss and PR thickness on SD-OCT volumes acquired at baseline, month 2, 6 and 12. The difference in the change of PR loss area was compared between treatment arms. Change in PR thickness adjacent to the GA borders and in the whole 20 degrees scanning area was compared between treatment arms.

MAIN OUTCOME MEASURES

Square root transformed PR loss area in μm or mm, PR thickness in μm, PR loss/RPE loss ratio.

RESULTS

A total of 31,556 B-Scans of 644 SD-OCT volumes of 161 study eyes (AM: 52, AEOM: 54, SM: 56) were evaluated from baseline to month 12. Comparison of mean change in PR loss area revealed statistically significantly less growth in the AM group at month 2, 6 and 12 compared to SM (-41μm ± 219 vs. 77μm ± 126, p=0.0004; -5μm ± 221 vs. 156μm ± 139, p<0.0001; 106μm ± 400 vs. 283μm ± 226 p=0.0014). PR thinning was significantly reduced under monthly treatment compared to sham within the GA junctional zone as well as throughout the 20 degrees area. A trend towards greater inhibition of PR loss compared to RPE loss was observed under therapy.

CONCLUSIONS

Distinct and reliable quantification of PR loss using deep learning-based algorithms offers an essential tool to evaluate therapeutic efficacy in slowing disease progression. PR loss and thinning are reduced by intravitreal complement C3 inhibition. Automated quantification of PR loss/maintenance based on OCT images is an ideal approach to reliably monitor disease activity and therapeutic efficacy in GA management in clinical routine and regulatory trials.

Evaluating a Causal Relationship between Complement Factor I Protein Level and Advanced Age-Related Macular Degeneration Using Mendelian Randomization

Importance

Risk of advanced age-related macular degeneration (AAMD) is associated with rare genetic variants in the gene encoding Complement factor I (CFI), which is associated with lower circulating CFI protein levels, but the nature of the relationship is unclear.

Objective

Can genetic factors be used to infer whether low circulating CFI is associated with AAMD risk?

Design

Two-sample inverse variance weighted Mendelian Randomisation (MR) was used to evaluate evidence for a relationship between CFI levels and AAMD risk, comparing CFI levels from genetically predefined subsets in AAMD and control cohorts.

Setting

Published genetic and proteomic data was combined with data from cohorts of Geographic Atrophy (GA) patients in a series of MR analyses.

Participants

We derived genetic instruments for systemic CFI level in 3,301 healthy European participants in the INTERVAL study. To evaluate a genetic causal odds ratio (OR) for the effect of CFI levels on AAMD risk, we used results from a genome-wide association study of 12,711 AAMD cases and 14,590 European controls from the International AMD Genomics Consortium (IAMDGC), and CFI levels from patients entered into the research studies SCOPE and SIGHT.

Results

We identified one common CFI variant rs7439493 which was strongly associated with low CFI level, explaining 4.8% of phenotypic variance. Using rs7439493 our MR analysis estimated that AAMD odds increased per standard deviation (SD) decrease in CFI level; OR 1.47 (95% confidence interval (CI) 1.30-1.65, P=2.1×10-10). We identified one rare variant (rs141853578 encoding p.Gly119Arg) which was genome-wide significantly associated with CFI levels after imputation; based on this, a 1 SD decrease in CFI leads to increased AAMD odds of 1.79 (95% CI 1.46-2.19, P=1.9×10-8). The rare variant rs141853578 explained a further 1.7% of phenotypic variance. To benchmark the effect of low CFI levels on AAMD odds using a CFI-specific proteomic assay, we estimated the effect using CFI levels from 24 rs141853578 positive GA patients; each 1 SD (3.5μg/mL) reduction in CFI was associated with 1.67 fold increased odds of AAMD (95% CI 1.40-2.00, P=1.85×10-8).

Conclusion and relevance

Excellent concordance in direction and effect size derived from rare and common variant calculations provide good genetic evidence for a potentially causal role of lower CFI level increasing AAMD risk.

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.

Progress of clinical therapies for dry age-related macular degeneration

Dry age-related macular degeneration (AMD) is a progressive blinding disease that currently affects millions of people worldwide with no successful treatment available. Significant research efforts are currently underway to develop therapies aimed at slowing the progression of this disease or, more notably, reversing it. Here the therapies which have reached clinical trial for treatment of dry AMD were reviewed. A thorough search of PubMed, Embase, and Clinicaltrials.gov has led to a comprehensive collection of the most recent strategies being evaluated. This review also endeavors to assess the status and future directions of therapeutics for this debilitating condition.

Deep Learning-Based Automatic Detection of Ellipsoid Zone Loss in Spectral-Domain OCT for Hydroxychloroquine Retinal Toxicity Screening

PURPOSE

Retinal toxicity resulting from hydroxychloroquine use manifests photoreceptor loss and disruption of the ellipsoid zone (EZ) reflectivity band detectable on spectral-domain (SD) OCT imaging. This study investigated whether an automatic deep learning-based algorithm can detect and quantitate EZ loss on SD OCT images with an accuracy comparable with that of human annotations.

DESIGN

Retrospective analysis of data acquired in a prospective, single-center, case-control study.

PARTICIPANTS

Eighty-five patients (168 eyes) who were long-term hydroxychloroquine users (average exposure time, 14 ± 7.2 years).

METHODS

A mask region-based convolutional neural network (M-RCNN) was implemented and trained on individual OCT B-scans. Scan-by-scan detections were aggregated to produce an en face map of EZ loss per 3-dimensional SD OCT volume image. To improve the accuracy and robustness of the EZ loss map, a dual network architecture was proposed that learns to detect EZ loss in parallel using horizontal (horizontal mask region-based convolutional neural network [M-RCNN_H]) and vertical (vertical mask region-based convolutional neural network [M-RCNN_V]) B-scans independently. To quantify accuracy, 10-fold cross-validation was performed.

MAIN OUTCOME MEASURES

Precision, recall, intersection over union (IOU), F1-score metrics, and measured total EZ loss area were compared against human grader annotations and with the determination of toxicity based on the recommended screening guidelines.

RESULTS

The combined projection network demonstrated the best overall performance: precision, 0.90 ± 0.09; recall, 0.88 ± 0.08; and F1 score, 0.89 ± 0.07. The combined model performed superiorly to the M-RCNN_H only model (precision, 0.79 ± 0.17; recall, 0.96 ± 0.04; IOU, 0.78 ± 0.15; and F1 score, 0.86 ± 0.12) and M-RCNN_V only model (precision, 0.71 ± 0.21; recall, 0.94 ± 0.06; IOU, 0.69 ± 0.21; and F1 score, 0.79 ± 0.16). The accuracy was comparable with the variability of human experts: precision, 0.85 ± 0.09; recall, 0.98 ± 0.01; IOU, 0.82 ± 0.12; and F1 score, 0.91 ± 0.06. Automatically generated en face EZ loss maps provide quantitative SD OCT metrics for accurate toxicity determination combined with other functional testing.

CONCLUSIONS

The algorithm can provide a fast, objective, automatic method for measuring areas with EZ loss and can serve as a quantitative assistance tool to screen patients for the presence and extent of toxicity.

Geographic Atrophy Progression Is Associated With Choriocapillaris Flow Deficits Measured With Optical Coherence Tomographic Angiography

Purpose

The purpose of this study was to assess the associations between baseline choriocapillaris (CC) flow deficits and geographic atrophy (GA) progression.

Methods

In this prospective cohort study, patients with GA underwent 3 × 3-mm macular spectral-domain optical coherence tomographic angiography (OCTA) at baseline and follow-up visits. Annual GA enlargement rate was defined as change of square root of GA area in 12 months. Shadow areas due to iris, media opacity, retinal vessels, and drusen were excluded. CC vessel density (CC-VD) in non-GA areas was measured using a validated machine-learning-based algorithm. Low perfusion area (LPA) was defined as capillary density below the 0.1 percentile threshold of the same location of 40 normal healthy control eye. Focal perfusion loss (FPL) was defined as percentage of CC loss within LPA compared with normal controls.

Results

Ten patients with GA were enrolled and followed for 26 months on average. At baseline, the mean GA area was 0.84 ± 0.70 mm2. The mean CC-VD was 44.5 ± 15.2%, the mean LPA was 4.29 ± 2.6 mm2, and the mean FPL was 50.4 ± 28.2%. The annual GA enlargement rate was significantly associated with baseline CC-VD (r = -0.816, P = 0.004), LPA (r = 0.809, P = 0.005), and FPL (r = 0.800, P = 0.005), but not with age (r = 0.008, P = 0.98) and GA area (r = -0.362, P = 0.30).

Conclusions

Baseline CC flow deficits were significantly associated with a faster GA enlargement over the course of 1 year, suggesting the choriocapillaris perfusion outside of a GA area may play a role in GA progression.