Comparing generative and retrieval-based chatbots in answering patient questions regarding age-related macular degeneration and diabetic retinopathy.

BACKGROUND/AIMS: To compare the performance of generative versus retrieval-based chatbots in answering patient inquiries regarding age-related macular degeneration (AMD) and diabetic retinopathy (DR). METHODS: We evaluated four chatbots: generative models (ChatGPT-4, ChatGPT-3.5 and Google Bard) and a retrieval-based model (OcularBERT) in a cross-sectional study. Their response accuracy to 45 questions (15 AMD, 15 DR and 15 others) was evaluated and compared. Three masked retinal specialists graded the responses using a three-point Likert scale: either 2 (good, error-free), 1 (borderline) or 0 (poor with significant inaccuracies). The scores were aggregated, ranging from 0 to 6. Based on majority consensus among the graders, the responses were also classified as 'Good', 'Borderline' or 'Poor' quality. RESULTS: Overall, ChatGPT-4 and ChatGPT-3.5 outperformed the other chatbots, both achieving median scores (IQR) of 6 (1), compared with 4.5 (2) in Google Bard, and 2 (1) in OcularBERT (all p ≤8.4×10-3). Based on the consensus approach, 83.3% of ChatGPT-4's responses and 86.7% of ChatGPT-3.5's were rated as 'Good', surpassing Google Bard (50%) and OcularBERT (10%) (all p ≤1.4×10-2). ChatGPT-4 and ChatGPT-3.5 had no 'Poor' rated responses. Google Bard produced 6.7% Poor responses, and OcularBERT produced 20%. Across question types, ChatGPT-4 outperformed Google Bard only for AMD, and ChatGPT-3.5 outperformed Google Bard for DR and others. CONCLUSION: ChatGPT-4 and ChatGPT-3.5 demonstrated superior performance, followed by Google Bard and OcularBERT. Generative chatbots are potentially capable of answering domain-specific questions outside their original training. Further validation studies are still required prior to real-world implementation.

Defining the structure-function relationship of specific lesions in early and advanced age-related macular degeneration.

The objective of this study is to define structure-function relationships of pathological lesions related to age-related macular degeneration (AMD) using microperimetry and multimodal retinal imaging. We conducted a cross-sectional study of 87 patients with AMD (30 eyes with early and intermediate AMD and 110 eyes with advanced AMD), compared to 33 normal controls (66 eyes) recruited from a single tertiary center. All participants had enface and cross-sectional optical coherence tomography (Heidelberg HRA-2), OCT angiography, color and infra-red (IR) fundus and microperimetry (MP) (Nidek MP-3) performed. Multimodal images were graded for specific AMD pathological lesions. A custom marking tool was used to demarcate lesion boundaries on corresponding enface IR images, and subsequently superimposed onto MP color fundus photographs with retinal sensitivity points (RSP). The resulting overlay was used to correlate pathological structural changes to zonal functional changes. Mean age of patients with early/intermediate AMD, advanced AMD and controls were 73(SD = 8.2), 70.8(SD = 8), and 65.4(SD = 7.7) years respectively. Mean retinal sensitivity (MRS) of both early/intermediate (23.1 dB; SD = 5.5) and advanced AMD (18.1 dB; SD = 7.8) eyes were significantly worse than controls (27.8 dB, SD = 4.3) (p < 0.01). Advanced AMD eyes had significantly more unstable fixation (70%; SD = 63.6), larger mean fixation area (3.9 mm2; SD = 3.0), and focal fixation point further away from the fovea (0.7 mm; SD = 0.8), than controls (29%; SD = 43.9; 2.6 mm2; SD = 1.9; 0.4 mm; SD = 0.3) (p ≤ 0.01). Notably, 22 fellow eyes of AMD eyes (25.7 dB; SD = 3.0), with no AMD lesions, still had lower MRS than controls (p = 0.04). For specific AMD-related lesions, end-stage changes such as fibrosis (5.5 dB, SD = 5.4 dB) and atrophy (6.2 dB, SD = 7.0 dB) had the lowest MRS; while drusen and pigment epithelial detachment (17.7 dB, SD = 8.0 dB) had the highest MRS. Peri-lesional areas (20.2 dB, SD = 7.6 dB) and surrounding structurally normal areas (22.2 dB, SD = 6.9 dB) of the retina with no AMD lesions still had lower MRS compared to controls (27.8 dB, SD = 4.3 dB) (p < 0.01). Our detailed topographic structure-function correlation identified specific AMD pathological changes associated with a poorer visual function. This can provide an added value to the assessment of visual function to optimize treatment outcomes to existing and potentially future novel therapies.

The Natural History of Retinal Sensitivity Loss in Diabetic Macular Ischemia over One Year Evaluated by Microperimetry.

Background/Objectives: This one-year prospective observational study, conducted at two centers, aimed to report the natural history of retinal sensitivity (RS) loss in diabetic macular ischemia (DMI). Methods: Patients with stable-treated proliferative diabetic retinopathy (PDR) were recruited if there was evidence of DMI on optical coherence tomography angiography, defined as a foveal avascular zone ≥ 0.5 mm2 or parafoveal capillary dropout ≥ 1 quadrant. The minimal visual acuity required for performing microperimetry (MP) was ≥54 Early Treatment Diabetic Retinopathy Study letters (Snellen equivalent 20/80). The overall RS (oRS) and pointwise sensitivity (PWS) within the 3 × 3 mm macula were assessed at baseline and twelve months. A value <25 decibels (dB) was defined as impaired RS, and a decrease of 2 and 7 dB was regarded as mild and severe loss, respectively. Results: A total of 88 patients (97 eyes) were included. No statistically significant MP changes were detected at one year. However, 10% of the cohort lost oRS ≥ 2 dB, and 73% lost ≥2 dB PWS in ≥5 loci, whereas 1% lost oRS ≥ 7 dB, and 4% lost ≥7 dB PWS in ≥5 loci. The foveola and temporal parafovea were the most vulnerable to severe RS loss. Compared to their counterpart, eyes with baseline oRS ≥ 25 dB had significantly more RS loss in the macula and superior parafovea (55% versus 32% and 53% versus 28%, both p = 0.01). Conclusions: Rather than oRS loss, ≥2 dB loss in PWS in ≥5 loci is a more feasible outcome measure for clinical trials in DMI.

Six-Year Outcomes in Subjects with Polypoidal Choroidal Vasculopathy in the EVEREST II Study.

INTRODUCTION: The EVEREST II study previously reported that intravitreally administered ranibizumab (IVR) combined with photodynamic therapy (PDT) achieved superior visual gain and polypoidal lesion closure compared to IVR alone in patients with polypoidal choroidal vasculopathy (PCV). This follow-up study reports the long-term outcomes 6 years after initiation of the EVEREST II study. METHODS: This is a non-interventional cohort study of 90 patients with PCV from 16 international trial sites who originally completed the EVEREST II study. The long-term outcomes were assessed during a recall visit at about 6 years from commencement of EVEREST II. RESULTS: The monotherapy and combination groups contained 41 and 49 participants, respectively. The change in best-corrected visual acuity (BCVA) from baseline to year 6 was not different between the monotherapy and combination groups; - 7.4 ± 23.0 versus - 6.1 ± 22.4 letters, respectively. The combination group had greater central subfield thickness (CST) reduction compared to the monotherapy group at year 6 (- 179.9 vs - 74.2 µm, p = 0.011). Fewer eyes had subretinal fluid (SRF)/intraretinal fluid (IRF) in the combination versus monotherapy group at year 6 (35.4% vs 57.5%, p = 0.032). Factors associated with BCVA at year 6 include BCVA (year 2), CST (year 2), presence of SRF/IRF at year 2, and number of anti-VEGF treatments (years 2-6). Factors associated with presence of SRF/IRF at year 6 include combination arm (OR 0.45, p = 0.033), BCVA (year 2) (OR 1.53, p = 0.046), and presence of SRF/IRF (year 2) (OR 2.59, p = 0.042). CONCLUSION: At 6 years following the EVEREST II study, one-third of participants still maintained good vision. As most participants continued to require treatment after exiting the initial trial, ongoing monitoring and re-treatment regardless of polypoidal lesion status are necessary in PCV. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01846273.

Central serous chorioretinopathy: An evidence-based treatment guideline.

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) combined with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Polypoidal Choroidal Vasculopathy: Evaluation Based on 3-Dimensional Reconstruction of OCT Angiography.

OBJECTIVE: Three-dimensional (3D) reconstruction using swept-source OCT angiography (SS-OCTA) can provide insights into the nature and structure of polypoidal choroidal vasculopathy (PCV) and its component parts, the polypoidal lesion (PL) and the branching neovascular network (BNN). This study aims to describe novel observations of PCV using 3D reconstruction of SS-OCTA, and to compare these observations with similar images of type I macular neovascularization (MNV) typical neovascular age-related macular degeneration (nAMD). DESIGN: Clinical case series. SUBJECTS: Patients with PCV in either eye from clinical studies conducted in a tertiary retina center. METHODS: Images with prespecified SS-OCTA imaging protocol were obtained and reconstructed in 3D. Forty neovascularization lesions (30 PCV and 10 typical nAMD) based on SS-OCTA were analyzed. MAIN OUTCOME MEASURES: The following 3 specific features were evaluated: (1) the pattern of flow signal within the PLs as either homogenous or showing internal vascular architecture; (2) the configuration of the BNN as hypermature, mature, or immature; and (3) the spatial arrangement of the PLs in relation to the BNN. Comparisons were made between PCV and typical nAMD. RESULTS: All PLs exhibited internal vascular architecture in the form of coil-like loops and none exhibited homogenous flow. Small focal nodules were present within this internal vascular architecture in 70% of PLs. Branching neovascular networks exhibited a hypermature/mature configuration (100 vs. 50%, P < 0.01) and were associated with thicker choroid compared with typical nAMD type 1 MNV (238.7 ± 104.3 vs. 155.6 ± 49.2, P = 0.02). The BNN and PL were located at distinct anteroposterior planes in 81% of the eyes. CONCLUSIONS: We identified proliferating vasculature in both the PL and the BNN. Comparison of the configuration suggests that the BNN represents a more chronic and inactive lesion than the PL. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Macular neovascularization and polypoidal choroidal vasculopathy: phenotypic variations, pathogenic mechanisms and implications in management.

Advances in imaging have led to improved ability to characterize variations in clinical sub-phenotypes of macular neovascularization (MNV) in Age-related macular degeneration (AMD). Polypoidal choroidal vasculopathy (PCV) was initially described based on characteristic features observed in indocyanine green angiography (ICGA) and was thought to be a distinct entity from AMD. However, subsequent careful observations based on confocal scanning laser ophthalmoscopy-based ICGA, optical coherence tomography (OCT) and OCT angiography have led researchers to appreciate similarities between PCV lesion and type 1 MNV in typical neovascular AMD. Concurrently, clinical trials have shown that anti-VEGF monotherapy can achieve favourable visual outcome in the majority of eyes with PCV. These learnings have led to a shift in the way PCV is managed over the past decade. Recent studies have supported the use of non-ICGA based imaging modality to screen for PCV and the adoption of anti-VEGF monotherapy as initial therapy for PCV. A focus of recent research has been in the understanding of the role of choroidal alterations in the pathogenesis of PCV. The concept of pachychoroid in leading to outer retinal ischemia has garnered increasing support. Future research in this area should evaluate the potential of choroidal morphology in guiding personalized therapy in PCV.

Features Associated With Vision in Eyes With Subfoveal Fibrosis From Neovascular Age-Related Macular Degeneration.

PURPOSE: To report the characteristics and correlation of visual acuity in eyes treated for neovascular age-related macular degeneration (nAMD) and developed fibrosis. DESIGN: Case-control study. METHODS: Three hundred fifty-six treatment-naive nAMD eyes that were treated for 12 months were included. Fibrosis was defined as present if well-defined hyperreflective material (HRM) were present between the neurosensory retina and the Bruch membrane on optical coherence tomography (OCT) that correlated with well-defined regions of yellowish pallor on fundus photography and/or staining on fluorescence angiography. OCT features of subfoveal fibrosis and the overlying retina were correlated with visual acuity at month 12. RESULTS: Sixty-three eyes (20.3%) developed incident fibrosis at month 12. Compared with eyes that did not develop fibrosis, these eyes had lower baseline vision (49 vs 54 letters, P = .02) and more of them had type 2 macular neovascularization (15.0 vs 8.8%, P = .03), larger lesion area (29.6 vs 15.1 mm2, P = .02), and subretinal hemorrhage ≥4 disc diameters (44.4% vs 19.8%, P < .01). Visual acuity was worse in the incident fibrosis compared with the group that never developed fibrosis by month 12. (-1.4±17.1 versus +6.0±17.4 letters, P < .01). In 83 eyes that had subfoveal fibrosis, better vision was associated with intact ellipsoid zone-external limiting membrane complex (ß coefficient 29.4, 95% CI 14.2-44.6, P < .01), whereas worse vision was associated with retinal pigment epithelium (RPE)-involving HRM, HRM above the RPE, and width of HRM (ß coefficients -25.4 [95% CI -36.3 to -14.6], P < .01; -23.5 [95% CI -39.0 to -7.9], P < .01; and -3.8 [95% CI -7.2 to -0.4], P = .03, respectively). CONCLUSION: Although fibrosis is associated with poorer visual outcome, preservation of external limiting membrane and level of fibrosis relative to the RPE are associated with visual outcomes.

Is Kidney Function Associated with Age-Related Macular Degeneration?: Findings from the Asian Eye Epidemiology Consortium.

PURPOSE: Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies. METHODS: Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups. MAIN OUTCOME MEASURES: Odds ratio (OR) of early and late AMD. RESULTS: Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149). CONCLUSIONS: Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Relationship Between Retinal Layer Thickness and Genetic Susceptibility to Age-Related Macular Degeneration in Asian Populations.

Purpose: For OCT retinal thickness measurements to be used as a prodromal age-related macular degeneration (AMD) risk marker, the 3-dimensional (3D) topographic variation of the relationship between genetic susceptibility to AMD and retinal thickness needs to be assessed. We aimed to evaluate individual retinal layer thickness changes and topography at the macula that are associated with AMD genetic susceptibility. Design: Genetic association study. Participants: A total of 1579 healthy participants (782 Chinese, 353 Malays, and 444 Indians) from the multiethnic Singapore Epidemiology of Eye Diseases study were included. Methods: Spectral-domain OCT and automatic segmentation of individual retinal layers were performed to produce 10 retinal layer thickness measurements at each ETDRS subfield, producing 3D topographic information. Age-related macular degeneration genetic susceptibility was represented via single nucleotide polymorphisms (SNPs) and aggregated via whole genome (overall) and pathway-specific age-related macular degeneration polygenic risk score (PRSAMD). Main Outcome Measures: Associations of individual SNPs, overall PRSAMD, and pathway-specific PRSAMD with retinal thickness were analyzed by individual retinal layer and ETDRS subfield. Results: CFH rs10922109, ARMS2-HTRA1 rs3750846, and LIPC rs2043085 were the top AMD susceptibility SNPs associated with retinal thickness of individual layers (P < 1.67 × 10-3), all at the central subfield. The overall PRSAMD was most associated with thinner L9 (outer segment photoreceptor/retinal pigment epithelium complex) thickness at the central subfield (ß = -0.63 µm; P = 5.45 × 10-9). Pathway-specific PRSAMD for the complement cascade (ß = -0.53 µm; P = 9.42 × 10-7) and lipoprotein metabolism (ß = -0.05 µm; P = 0.0061) were associated with thinner photoreceptor layers (L9 and L7 [photoreceptor inner/outer segments], respectively) at the central subfield. The mean PRSAMD score was larger among Indians compared with that of the Chinese and had the thinnest thickness at the L9 central subfield (ß = -1.00 µm; P = 2.91 × 10-7; R2 = 5.5%). Associations at other retinal layers and ETDRS regions were more heterogeneous. Conclusions: Overall genetic susceptibility to AMD and the aggregate effects of the complement cascade and lipoprotein metabolism pathway are associated most significantly with L7 and L9 photoreceptor thinning at the central macula in healthy individuals. Photoreceptor thinning has potential to be a prodromal AMD risk marker, and topographic variation should be considered. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Contribution of common and rare variants to Asian neovascular age-related macular degeneration subtypes.

Neovascular age-related macular degeneration (nAMD), along with its clinical subtype known as polypoidal choroidal vasculopathy (PCV), are among the leading causes of vision loss in elderly Asians. In a genome-wide association study (GWAS) comprising 3,128 nAMD (1,555 PCV and 1,573 typical nAMD), and 5,493 controls of East Asian ancestry, we identify twelve loci, of which four are novel ([Formula: see text]). Substantial genetic sharing between PCV and typical nAMD is noted (rg = 0.666), whereas collagen extracellular matrix and fibrosis-related pathways are more pronounced for PCV. Whole-exome sequencing in 259 PCV patients revealed functional rare variants burden in collagen type I alpha 1 chain gene (COL1A1; [Formula: see text]) and potential enrichment of functional rare mutations at AMD-associated loci. At the GATA binding protein 5 (GATA5) locus, the most significant GWAS novel loci, the expressions of genes including laminin subunit alpha 5 (Lama5), mitochondrial ribosome associated GTPase 2 (Mtg2), and collagen type IX alpha 3 chain (Col9A3), are significantly induced during retinal angiogenesis and subretinal fibrosis in murine models. Furthermore, retinoic acid increased the expression of LAMA5 and MTG2 in vitro. Taken together, our data provide insights into the genetic basis of AMD pathogenesis in the Asian population.

Efficacy, durability, and safety of faricimab in patients from Asian countries with neovascular age-related macular degeneration: 1-Year subgroup analysis of the TENAYA and LUCERNE trials.

PURPOSE: To evaluate 1-year efficacy, durability, and safety of faricimab among patients from Asian countries in the TENAYA/LUCERNE trials of neovascular age-related macular degeneration (nAMD). METHODS: Treatment-naïve patients with nAMD were randomly assigned (1:1) to faricimab 6.0 mg up to every 16 weeks (Q16W), based on disease activity at weeks 20 and 24, or aflibercept 2.0 mg Q8W. The primary endpoint was change in best-corrected visual acuity (BCVA) from baseline averaged over weeks 40, 44, and 48. RESULTS: In the pooled TENAYA/LUCERNE trials, there were 120 (9.0%) and 1209 (91.0%) patients in the Asian (faricimab n = 61; aflibercept n = 59) and non-Asian country (faricimab n = 604; aflibercept n = 605) subgroups, respectively. In the Asian country subgroup, mean BCVA change from baseline at the primary endpoint visits was 7.1 (95% CI, 4.3-9.8) letters with faricimab and 7.2 (4.4-10.0) letters with aflibercept. In non-Asian country patients, mean vision gains were 6.1 (5.2-7.1) and 5.7 (4.8-6.7) letters with faricimab and aflibercept, respectively. At week 48, 59.6% of Asian country patients in the faricimab group achieved Q16W dosing (vs. 43.9% non-Asian) and 91.2% achieved ≥ Q12W dosing (vs. 77.5% non-Asian). Central subfield thickness reductions were similar between the subgroups, with meaningful and similar reductions from baseline observed at the primary endpoint visits and over time. Faricimab was well tolerated in both subgroups, with an acceptable safety profile. CONCLUSION: Consistent with the global TENAYA/LUCERNE findings, faricimab up to Q16W showed sustained visual and anatomical benefits in patients with nAMD from Asian and non-Asian countries. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03823287 (TENAYA); NCT03823300 (LUCERNE). Date of registration: January 30, 2019.

Potential for Treatment Interval Extension in Eyes with nAMD Disease Activity Post Loading Phase in HAWK and HARRIER.

INTRODUCTION: The HAWK and HARRIER studies evaluated the efficacy and safety of brolucizumab versus aflibercept in treatment-naïve eyes with neovascular age-related macular degeneration. Based on the study design, brolucizumab-treated eyes adjusted to a q8w regimen because the presence of disease activity (DA) at the end of the matched loading phase (Week 16) could not subsequently extend to a q12w interval. The aim of this post hoc analysis was to assess subsequent DA in this subgroup to determine the potential for interval extensions during the first year of treatment. METHODS: Pooled data from the brolucizumab 6 mg arms and aflibercept arms of HAWK and HARRIER were included. Presence of DA was determined by the masked investigator based on their assessment of functional and anatomical parameters measured by optical coherence tomography. DA was compared at DA assessments, conducted at Weeks 16, 20, 32, and 44; fluid was also assessed at the primary analysis at Week 48. RESULTS: Fewer brolucizumab- (22.8%) than aflibercept-treated (32.2%) eyes had DA at the first DA assessment at Week 16. In eyes with investigator-identified DA at Week 16, BCVA change from baseline to Week 96 was comparable between treatment arms. Fewer brolucizumab- than aflibercept-treated eyes had DA at each subsequent DA assessment in Year 1: 31.8% vs 39.1% (Week 20), 27.3% vs 43.5% (Week 32), and 17.3% vs 31.2% (Week 44). Fewer eyes treated with brolucizumab than aflibercept had intraretinal and/or subretinal fluid: 35.3% vs 43.5% (Week 20), 55.8% vs 69.6% (Week 32), 30.0% vs 43.1% (Week 44), and 48.6% vs 68.6% (Week 48). CONCLUSION: These findings indicate that, in eyes that still had DA 8 weeks after the final dose of loading phase, brolucizumab-treated eyes had improved fluid resolution and higher potential for treatment interval extension than aflibercept-treated eyes during the first year of treatment.

The economic burden of inherited retinal disease in Singapore: a prevalence-based cost-of-illness study.

OBJECTIVE: To assess the economic impact of inherited retinal disease (IRD) among Singaporeans. METHODS: IRD prevalence was calculated using population-based data. Focused surveys were conducted for sequentially enrolled IRD patients from a tertiary hospital. The IRD cohort was compared to the age- and gender-matched general population. Economic costs were expanded to the national IRD population to estimate productivity and healthcare costs. RESULTS: National IRD caseload was 5202 cases (95% CI, 1734-11273). IRD patients (n = 95) had similar employment rates to the general population (67.4% vs. 70.7%; p = 0.479). Annual income was lower among IRD patients than the general population (SGD 19,500 vs. 27,161; p < 0.0001). Employed IRD patients had lower median income than the general population (SGD 39,000 vs. 52,650; p < 0.0001). Per capita cost of IRD was SGD 9382, with a national burden of SGD 48.8 million per year. Male gender (beta of SGD 6543, p = 0.003) and earlier onset (beta of SGD 150/year, p = 0.009) predicted productivity loss. Treatment of the most economically impacted 10% of IRD patients with an effective IRD therapy required initial treatment cost of less than SGD 250,000 (USD 188,000) for cost savings to be achieved within 20 years. CONCLUSIONS: Employment rates among Singaporean IRD patients were the same as the general population, but patient income was significantly lower. Economic losses were driven in part by male patients with early age of onset. Direct healthcare costs contributed relatively little to the financial burden.

Single-cell transcriptomics reveals maturation of transplanted stem cell-derived retinal pigment epithelial cells toward native state.

Transplantation of stem cell-derived retinal pigment epithelial (RPE) cells is considered a viable therapeutic option for age-related macular degeneration (AMD). Several landmark Phase I/II clinical trials have demonstrated safety and tolerability of RPE transplants in AMD patients, albeit with limited efficacy. Currently, there is limited understanding of how the recipient retina regulates the survival, maturation, and fate specification of transplanted RPE cells. To address this, we transplanted stem cell-derived RPE into the subretinal space of immunocompetent rabbits for 1 mo and conducted single-cell RNA sequencing analyses on the explanted RPE monolayers, compared to their age-matched in vitro counterparts. We observed an unequivocal retention of RPE identity, and a trajectory-inferred survival of all in vitro RPE populations after transplantation. Furthermore, there was a unidirectional maturation toward the native adult human RPE state in all transplanted RPE, regardless of stem cell resource. Gene regulatory network analysis suggests that tripartite transcription factors (FOS, JUND, and MAFF) may be specifically activated in posttransplanted RPE cells, to regulate canonical RPE signature gene expression crucial for supporting host photoreceptor function, and to regulate prosurvival genes required for transplanted RPE's adaptation to the host subretinal microenvironment. These findings shed insights into the transcriptional landscape of RPE cells after subretinal transplantation, with important implications for cell-based therapy for AMD.

Joint Multimodal Deep Learning-based Automatic Segmentation of Indocyanine Green Angiography and OCT Images for Assessment of Polypoidal Choroidal Vasculopathy Biomarkers.

Purpose: To develop a fully-automatic hybrid algorithm to jointly segment and quantify biomarkers of polypoidal choroidal vasculopathy (PCV) on indocyanine green angiography (ICGA) and spectral domain-OCT (SD-OCT) images. Design: Evaluation of diagnostic test or technology. Participants: Seventy-two participants with PCV enrolled in clinical studies at Singapore National Eye Center. Methods: The dataset consisted of 2-dimensional (2-D) ICGA and 3-dimensional (3-D) SD-OCT images which were spatially registered and manually segmented by clinicians. A deep learning-based hybrid algorithm called PCV-Net was developed for automatic joint segmentation of biomarkers. The PCV-Net consisted of a 2-D segmentation branch for ICGA and 3-D segmentation branch for SD-OCT. We developed fusion attention modules to connect the 2-D and 3-D branches for effective use of the spatial correspondence between the imaging modalities by sharing learned features. We also used self-supervised pretraining and ensembling to further enhance the performance of the algorithm without the need for additional datasets. We compared the proposed PCV-Net to several alternative model variants. Main Outcome Measures: The PCV-Net was evaluated based on the Dice similarity coefficient (DSC) of the segmentations and the Pearson's correlation and absolute difference of the clinical measurements obtained from the segmentations. Manual grading was used as the gold standard. Results: The PCV-Net showed good performance compared to manual grading and alternative model variants based on both quantitative and qualitative analyses. Compared to the baseline variant, PCV-Net improved the DSC by 0.04 to 0.43 across the different biomarkers, increased the correlations, and decreased the absolute differences of clinical measurements of interest. Specifically, the largest average (mean ± standard error) DSC improvement was for intraretinal fluid, from 0.02 ± 0.00 (baseline variant) to 0.45 ± 0.06 (PCV-Net). In general, improving trends were observed across the model variants as more technical specifications were added, demonstrating the importance of each aspect of the proposed method. Conclusion: The PCV-Net has the potential to aid clinicians in disease assessment and research to improve clinical understanding and management of PCV. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Ten-Year Incidence of Fibrosis and Risk Factors for Its Development in Neovascular Age-Related Macular Degeneration.

PURPOSE: To report the incidence and risk factors for fibrosis at 10 years in a large cohort of persons with neovascular age-related macular degeneration (nAMD). DESIGN: Retrospective, multicenter, cohort study. METHODS: We included 225 naive nAMD eyes that underwent intravitreal anti-vascular endothelial growth factor treatment over 10 years of follow-up at two Italian referral centers. Demographic and clinical data were reviewed at baseline and on an annual basis. Onset of fibrosis was defined by clinically assessing photographs, fundus descriptions, or fluorescein angiograms. Optical coherence tomography (OCT) scans of fibrosis were inspected by an external reading center and graded as subretinal pigment epithelium (RPE), mixed, or subretinal. RESULTS: The mean age at baseline was of 72.1 ± 6.9 years. The incidence rate of fibrosis was estimated to be 8.9 per 100 person-years, with a cumulative incidence of 62.7% at 10 years. Fibrotic lesions were sub-RPE in 46.1%, mixed in 29.8%, and subretinal in 22.7%. Independent factors associated with fibrosis included the following: larger central subfield thickness variation (P < .001), submacular hemorrhages (P = .008), higher number of injections (P = .01), and worse baseline visual acuity (VA) (P = .03). Type 2 macular neovascularization was significantly associated with mixed and subretinal fibrosis. VA significantly declined over 10 years (-16.4 Early Treatment Diabetic Retinopathy Study [ETDRS] letters), particularly in eyes with mixed and subretinal fibrosis (P < .001). CONCLUSIONS: We identified a 62.7% cumulative incidence of fibrosis in a large nAMD cohort at 10 years. Fibrosis was more common with frequent reactivations and lower baseline VA; its onset had a significant impact on final VA. This supports the hypothesis that nAMD patients should be promptly treated with proactive regimens.