Comprehensive functional characterization of complement factor I rare variant genotypes identified in the SCOPE geographic atrophy cohort.

Rare variants (RVs) in the gene encoding the regulatory enzyme complement factor I (CFI; FI) that reduce protein function or levels increase age-related macular degeneration risk. A total of 3357 subjects underwent screening in the SCOPE natural history study for geographic atrophy secondary to age-related macular degeneration, including CFI sequencing and serum FI measurement. Eleven CFI RV genotypes that were challenging to categorize as type I (low serum level) or type II (normal serum level, reduced enzymatic function) were characterized in the context of pure FI protein in C3b and C4b fluid phase cleavage assays and a novel bead-based functional assay (BBFA) of C3b cleavage. Four variants predicted or previously characterized as benign were analyzed by BBFA for comparison. In all, three variants (W51S, C67R, and I370T) resulted in low expression. Furthermore, four variants (P64L, R339Q, G527V, and P528T) were identified as being highly deleterious with IC50s for C3b breakdown >1 log increased versus the WT protein, while two variants (K476E and R474Q) were ∼1 log reduced in function. Meanwhile, six variants (P50A, T203I, K441R, E548Q, P553S, and S570T) had IC50s similar to WT. Odds ratios and BBFA IC50s were positively correlated (r = 0.76, p < 0.01), while odds ratios versus combined annotation dependent depletion (CADD) scores were not (r = 0.43, p = 0.16). Overall, 15 CFI RVs were functionally characterized which may aid future patient stratification for complement-targeted therapies. Pure protein in vitro analysis remains the gold standard for determining the functional consequence of CFI RVs.

Impaired glutamylation of RPGRORF15 underlies the cone-dominated phenotype associated with truncating distal ORF15 variants.

Pathogenic variants in the Retinitis pigmentosa GTPase regulator (RPGR) gene lead to a clinically severe form of X-linked retinal dystrophy. However, it remains unclear why some variants cause a predominant rod, while others result in a cone-dominated phenotype. Post-translational glutamylation of the photoreceptor-specific RPGRORF15 isoform by the TTLL5 enzyme is essential for its optimal function in photoreceptors, and loss of TTLL5 leads to retinal dystrophy with a cone phenotype. Here we show that RPGR retinal disease, studied in a single cohort of 116 male patients, leads to a clear progressive shift from rod- to cone-dominating phenotype as the RPGRORF15 variant location approaches the distal part of the Open Reading Frame 15 (ORF15) region. The rod photoreceptor involvement on the contrary diminishes along the RGPR sequence, and the variants associated with the cone only phenotype are located predominantly in the very distal part, including the C-terminal basic domain. Moreover, these distal truncating RPGRORF15 variants disrupt the interaction with TTLL5 and lead to a significant impairment of RPGR glutamylation. Thus, consistent with the phenotype of TTLL5 pathogenic variants, our study shows that RPGRORF15 variants, which disrupt its basic domain and the interaction with TTLL5, also impair RPGR glutamylation and lead to the cone phenotype. This has implications for ongoing gene therapy clinical trials where the application of RPGR with impaired glutamylation may be less effective in treating RGPR dystrophies and may even convert a rod-cone dystrophy into a cone dystrophy phenotype.

Rare complement factor I variants associated with reduced macular thickness and age-related macular degeneration in the UK Biobank.

To evaluate potential diagnostic and therapeutic biomarkers for age-related macular degeneration (AMD), we identified 8433 UK Biobank participants with rare complement Factor I gene (CFI) variants, 579 with optical coherence tomography-derived macular thickness data. We stratified these variants by predicted gene expression and measured their association with retinal pigment epithelium-Bruch's membrane (RPE-BM) complex and retinal thicknesses at nine macular subfields, as well as AMD risk, using multivariable regression models adjusted for the common complement Factor H gene (CFH) p.Y402H and age-related maculopathy susceptibility protein 2 gene (ARMS2) p.A69S risk genotypes. CFI variants associated with low Factor I levels predicted a thinner mean RPE-BM (95% confidence interval [CI] -1.66 to -0.37 µm, P = 0.002) and retina (95% CI -5.88 to -0.13 µm, P = 0.04) and a higher AMD risk (odds ratio [OR] = 2.26, 95% CI 1.56 to 3.27, P < 0.001). CFI variants associated with normal Factor I levels did not impact mean RPE-BM/retinal thickness (P = 0.28; P = 0.99) or AMD risk (P = 0.97). CFH p.Y402H was associated with a thinner RPE-BM (95% CI -0.31 to -0.18 µm, P < 0.001 heterozygous; 95% CI -0.62 to -0.42 µm, P < 0.001 homozygous) and retina (95% CI -0.73 to -0.12 µm, P = 0.007 heterozygous; 95% CI -1.08 to -0.21 µm, P = 0.004 homozygous). ARMS2 p.A69S did not influence RPE-BM (P = 0.80 heterozygous; P = 0.12 homozygous) or retinal thickness (P = 0.75 heterozygous; P = 0.07 homozygous). p.Y402H and p.A69S exhibited a significant allele-dose response with AMD risk. Thus, CFI rare variants associated with low Factor I levels are robust predictors of reduced macular thickness and AMD. The observed association between macular thickness and CFH p.Y402H, but not ARMS2 p.A69S, highlights the importance of complement dysregulation in early pathogenesis.

CHOROIDAL VASCULARITY IN CHRONIC CENTRAL SEROUS CHORIORETINOPATHY AND ITS ASSOCIATION WITH RISK SINGLE-NUCLEOTIDE POLYMORPHISMS.

PURPOSE: To analyze the choroidal parameters of patients with chronic central serous chorioretinopathy (cCSC) and the association with central serous chorioretinopathy susceptibility genes. METHODS: The choroidal vascular index (CVI) was obtained by binarizing spectral domain optical coherence tomography enhanced depth images of patients with cCSC and healthy age-matched controls. Patients with cCSC were genotyped for three central serous chorioretinopathy susceptibility single-nucleotide polymorphisms: rs4844392 ( mir-29b-2/CD46 ), rs1329428 ( CFH ), and rs2379120 (upstream GATA5 ). RESULTS: One hundred three eyes with cCSC and 53 control eyes were included. There was a significant increase in the subfoveal choroidal area in both the affected (2.4 ± 0.6 mm 2 ) and fellow (2.2 ± 0.6 mm 2 ) eyes of patients with cCSC compared with controls (1.8 ± 0.5 mm 2 , P < 0.0001 and P < 0.0001). The CVI was reduced in patients with cCSC 63.5% ± 3.1% compared with controls 65.4% ± 2.3% ( P < 0.001) and also in the affected compared with the fellow eyes 64.6% ± 2.9% ( P < 0.01). There was a significant association between CVI in the cCSC group and presence of the risk single-nucleotide polymorphisms rs2379120 at GATA5 ( P < 0.01). CONCLUSION: The relative reduction of CVI in patients with cCSC may suggest a persistence of vessel hyperpermeability over dilation in chronic disease. GATA5 is associated with CVI in patients with cCSC and therefore may have a role in choroidal vascularity.

Diagnostic and therapeutic considerations in patients with bilateral diffuse uveal melanocytic proliferation.

PURPOSE: This review aims to summarize the current knowledge concerning the clinical features, diagnostic work-up, and therapeutic approach of bilateral diffuse uveal melanocytic proliferation (BDUMP). METHODS: A meticulous literature search was performed in the PubMed database. A supplementary search was made in Google Scholar to complete the collected items. Our search strategy utilized the following keywords: "bilateral diffuse uveal melanocytic proliferation", "BDUMP", and "Paraneoplastic Syndrome". Articles were considered based on their relevance, with the search spanning publications up to 2023. Studies were excluded if they did not contribute pertinent information or lacked methodological rigor. A critical appraisal of included studies was conducted, assessing study design, sample size, methodology, and potential bias, ensuring a thorough and transparent review process. RESULTS: BDUMP is a rare and potentially sight-threatening condition characterized by the bilateral proliferation of melanocytes within the uvea. BDUMP is typically observed in middle-aged or elderly individuals and is often associated with an underlying malignancy, most commonly of gastrointestinal origin. BDUMP is frequently misdiagnosed as a benign nevus or choroidal metastasis, leading to delayed diagnosis and treatment. The ophthalmic symptoms and signs typically precede the diagnosis of a systemic malignancy, emphasizing the crucial role of ophthalmologists in the recognition of BDUMP. Several diagnostic modalities can aid in the diagnosis of BDUMP, including ophthalmic examination, imaging studies such as optical coherence tomography, fluorescein angiography, and indocyanine green angiography, and biopsy of the uveal tissue. Treatment of BDUMP is directed towards the underlying malignancy and may include chemotherapy, radiotherapy, or surgical resection. Additionally, strict monitoring with regular follow-ups may contribute to the detection of new lesions and the reduction in the size of existing ones. CONCLUSIONS: BDUMP can be considered a potential biomarker in the management of malignancies, especially when the primary underlying tumor has not been detected. Further research is needed to better understand the pathogenesis of BDUMP and its association with malignancy.

Epiretinal membranes in patients with uveitis: an update on the current state of management.

PURPOSE: This review aims to summarize the current knowledge concerning the clinical features, diagnostic work-up, and therapeutic approach of uveitic epiretinal membranes (ERM). METHODS: A thorough investigation of the literature was conducted using the PubMed database. Additionally, a complementary search was carried out on Google Scholar to ensure the inclusion of all relevant items in the collection. RESULTS: ERM is an abnormal layer at the vitreoretinal interface, resulting from myofibroblastic cell proliferation along the inner surface of the central retina, causing visual impairment. Known by various names, ERM has diverse causes, including idiopathic or secondary factors, with ophthalmic imaging techniques like OCT improving detection. In uveitis, ERM occurrence is common, and surgical intervention involves pars plana vitrectomy with ERM peeling, although debates persist on optimal approaches. CONCLUSIONS: Histopathological studies and OCT advancements improved ERM understanding, revealing a diverse group of diseases without a unified model. Consensus supports surgery for uveitic ERM in progressive cases, but variability requires careful consideration and effective inflammation management. OCT biomarkers, deep learning, and surgical advances may enhance outcomes, and medical interventions and robotics show promise for early ERM intervention.

Generation of a Cone Photoreceptor-specific GNGT2 Reporter Line in Human Pluripotent Stem Cells.

Fluorescent reporter lines generated in human pluripotent stem cells are a highly useful tool to track, isolate, and analyze cell types and lineages in live cultures. Here, we generate the first human cone photoreceptor reporter cell line by CRISPR/Cas9 genome editing of a human embryonic stem cell (hESC) line to tag both alleles of the Guanine nucleotide-binding protein subunit gamma-T2 (GNGT2) gene with a mCherry reporter cassette. Three-dimensional optic vesicle-like structures were produced to verify reporter fidelity and track cones throughout their development in culture. The GNGT2-T2A-mCherry hESC line faithfully and robustly labels GNGT2-expressing cones throughout the entirety of their differentiation in vitro, recapitulating normal fetal expression of this gene. Our observations indicate that human cones undergo significant migratory activity during the course of differentiation in vitro. Consistent with this, our analysis of human fetal retinae from different stages of development finds positional differences of the cone population depending on their state of maturation. This novel reporter line will provide a useful tool for investigating human cone development and disease.

Associations with Non-Persistence with Intra-Vitreal Therapy for Neovascular Age-Related Macular Degeneration at 24 Months.

AIMS: The aim of the study was to investigate non-persistence with treatment for neovascular age-related macular degeneration (NvAMD) before day 720 (24 months) after initiation, explore associations with baseline characteristics and variation between sites. METHODS: Anonymised demographic and clinical data were extracted from electronic medical records at treating National Health Service (NHS) Trusts for NvAMD eyes starting intra-vitreal therapy from 2017 to 2018. Time to non-persistence with treatment, defined as no recorded attendance for either monitoring or treatment for a period ≥6 months, was visualised with a Kaplan-Meier survival plot. Associations with treatment non-persistence were investigated using a Cox proportional hazards model. RESULTS: Analysis included 7,970 eyes of 7,112 patients treated at 13 NHS trusts. Censoring deaths and those eyes in which treatment was stopped permanently, the Kaplan-Meier analyses demonstrated survival figures of 77.7% for persistence with treatment to day 360 and 71.8% to day 720. Hazard ratios for non-persistence with treatment were reduced at 10 sites, relative to the reference, with first-treated eye status and with baseline acuity worse than or equal to LogMAR 1.0. Hazard ratios increased with younger age, in the presence of other ocular co-morbidities and with baseline acuity better than or equal to LogMAR 0.5. After an episode of non-persistence, visual acuity decreased by at least 0.1 and 0.3 LogMAR in 39% and 18% of eyes, respectively. CONCLUSIONS: Non-persistence with treatment was common, especially in the first year of treatment, and was often associated with a decrease in visual acuity. Treatment site, baseline visual acuity, and age were the strongest predictors of treatment non-persistence before day 720. Understanding and addressing reasons for non-persistence are important to ensure that effective but expensive treatments are used cost-effectively and to maintain acuity. Variation in non-persistence between sites, even after adjustment for other variables, suggests that local factors in treatment provision may be particularly important.

Pigmentary anomaly caused by mosaic 3q22.2q29 duplication.

A 39-year-old woman sought advice regarding potential risks to her offspring due to previous possible diagnosis of incontinentia pigmenti. She had linear hyperpigmentation along the lines of Blaschko affecting the upper and lower limbs, and skin-coloured papules on the left palm. Ophthalmoscopy revealed hypopigmented spots in the macular region of the retina in each eye due to focal areas of depigmentation of the retinal pigment epithelium. An array comparative genomic hybridization on DNA extracted from a skin biopsy revealed a 63.63-Mb duplication, arr[GRCh37] 3q22.2q29(134212001_197837069)x3, on the long arm of chromosome 3. This case is an example of genetic mosaicism resulting from a de novo genetic defect arising at some point in embryonic development. Click here for the corresponding questions to this CME article.

The Role of the Choroid in Stargardt Disease.

Stargardt disease is the commonest juvenile macular dystrophy. It is caused by genetic mutations in the ABCA4 gene. Diagnosis is not always straightforward, and various phenocopies exist. Late-onset disease can be misdiagnosed with age-related macular disease. A correct diagnosis is particularly critical because of emergent gene therapies. Stargardt disease is known to affect retinal pigment epithelium and photoreceptors. Many studies have also highlighted the importance of the choroid in the diagnosis, pathophysiology, and progression of the disease. The choroid is in an integral relationship with the retinal pigment epithelium and photoreceptors, and its possible involvement during the disease should be considered. The purpose of this review is to analyze the current diagnostic tools for choroidal evaluation and the extrapolation of useful data for ophthalmologists and researchers studying the disease.

An Exploratory Study Provides Insights into MMP9 and Aß Levels in the Vitreous and Blood across Different Ages and in a Subset of AMD Patients.

Matrix metalloproteinase-9 (MMP9) and total amyloid-beta (Aß) are prospective biomarkers of ocular ageing and retinopathy. These were quantified by ELISA in the vitreous and blood from controls (n = 55) and in a subset of age-related macular degeneration (AMD) patients (n = 12) for insights and possible additional links between the ocular and systemic compartments. Vitreous MMP9 levels in control and AMD groups were 932.5 ± 240.9 pg/mL and 813.7 ± 157.6 pg/mL, whilst serum levels were 2228 ± 193 pg/mL and 2386.8 ± 449.4 pg/mL, respectively. Vitreous Aß in control and AMD groups were 1173.5 ± 117.1 pg/mL and 1275.6 ± 332.9 pg/mL, whilst plasma Aß were 574.3 ± 104.8 pg/mL and 542.2 ± 139.9 pg/mL, respectively. MMP9 and Aß showed variable levels across the lifecourse, indicating no correlation to each other or with age nor AMD status, though the smaller AMD cohort was a limiting factor. Aß and MMP9 levels in the vitreous and blood were unrelated to mean arterial pressure. Smoking, another modifiable risk, showed no association with vitreous Aß. However, smoking may be linked with vitreous (p = 0.004) and serum (p = 0.005) MMP9 levels in control and AMD groups, though this did not reach our elevated (p = 0.001) significance. A bioinformatics analysis revealed promising MMP9 and APP/Aß partners for further scrutiny, many of which are already linked with retinopathy.

Prevalence and phenotype associations of complement factor I mutations in geographic atrophy.

Rare variants in the complement factor I (CFI) gene, associated with low serum factor I (FI) levels, are strong risk factors for developing the advanced stages of age-related macular degeneration (AMD). No studies have been undertaken on the prevalence of disease-causing CFI mutations in patients with geographic atrophy (GA) secondary to AMD. A multicenter, cross-sectional, noninterventional study was undertaken to identify the prevalence of pathogenic rare CFI gene variants in an unselected cohort of patients with GA and low FI levels. A genotype-phenotype study was performed. Four hundred and sixty-eight patients with GA secondary to AMD were recruited to the study, and 19.4% (n = 91) demonstrated a low serum FI concentration (below 15.6 µg/ml). CFI gene sequencing on these patients resulted in the detection of rare CFI variants in 4.7% (n = 22) of recruited patients. The prevalence of CFI variants in patients with low serum FI levels and GA was 25%. Of the total patients recruited, 3.2% (n = 15) expressed a CFI variant classified as pathogenic or likely pathogenic. The presence of reticular pseudodrusen was detected in all patients with pathogenic CFI gene variants. Patients with pathogenic CFI gene variants and low serum FI levels might be suitable for FI supplementation in therapeutic trials.

Eplerenone for chronic central serous chorioretinopathy in patients with active, previously untreated disease for more than 4 months (VICI): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: In chronic central serous chorioretinopathy (CSCR), fluid accumulates in the subretinal space. CSCR is a common visually disabling condition that develops in individuals up to 60 years of age, and there is no definitive treatment. Previous research suggests the mineralocorticoid receptor antagonist, eplerenone, is effective for treating CSCR; however, this drug is not licensed for the treatment of patients with CSCR. We aimed to evaluate whether eplerenone was superior to placebo in terms of improving visual acuity in patients with chronic CSCR. METHODS: This randomised, double-blind, parallel-group, multicentre placebo-controlled trial was done at 22 hospitals in the UK. Participants were eligible if they were aged 18-60 years and had had treatment-naive CSCR for 4 months or more. Patients were randomly assigned (1:1) to either the eplerenone or the placebo group by a trial statistician through a password-protected system online. Allocation was stratified by best-corrected visual acuity (BCVA) and hospital. Patients were given either oral eplerenone (25 mg/day for 1 week, increasing to 50 mg/day for up to 12 months) plus usual care or placebo plus usual care for up to 12 months. All participants, care teams, outcome assessors, pharmacists, and members of the trial management group were masked to the treatment allocation. The primary outcome was BCVA, measured as letters read, at 12 months. All outcomes apart from safety were analysed on a modified intention-to-treat basis (participants who withdrew consent without contributing a post-randomisation BCVA measurement were excluded from the primary analysis population and from most secondary analysis populations). The trial is registered with ISRCTN, ISRCTN92746680, and is completed. FINDINGS: Between Jan 11, 2017, and Feb 22, 2018, we enrolled and randomly assigned 114 patients to receive either eplerenone (n=57) or placebo (n=57). Three participants in the placebo group withdrew consent without contributing a post-randomisation BCVA measurement and were excluded from the primary outcome analysis population. All patients from the eplerenone group and 54 patients from the placebo group were included in the primary outcome. Modelled mean BCVA at 12 months was 79·5 letters (SD 4·5) in the placebo group and 80·4 letters (4·6) in the eplerenone group, with an adjusted estimated mean difference of 1·73 letters (95% CI -1·12 to 4·57; p=0·24) at 12 months. Hyperkalaemia occurred in eight (14%) patients in each group. No serious adverse events were reported in the eplerenone group and three unrelated serious adverse events were reported in the placebo group (myocardial infarction [anticipated], diverticulitis [unanticipated], and metabolic surgery [unanticipated]). INTERPRETATION: Eplerenone was not superior to placebo for improving BCVA in people with chronic CSCR after 12 months of treatment. Ophthalmologists who currently prescribe eplerenone for CSCR should discontinue this practice. FUNDING: Efficacy and Mechanism Evaluation Programme, and National Institute for Health Research and Social Care.

Diagnostic Accuracy of Monitoring Tests of Fellow Eyes in Patients with Unilateral Neovascular Age-Related Macular Degeneration: Early Detection of Neovascular Age-Related Macular Degeneration Study.

PURPOSE: To evaluate the diagnostic accuracy of routinely used tests of visual function and retinal morphology compared with fundus fluorescein angiography (FFA) to detect onset of active macular neovascularization in unaffected fellow eyes of patients with unilateral neovascular age-related macular degeneration (nAMD). DESIGN: Prospective diagnostic accuracy cohort study conducted in 24 eye clinics in the United Kingdom over 3 years. PARTICIPANTS: Older adults (>50 years) with recently diagnosed unilateral nAMD with a fellow (study) eye free of nAMD. METHODS: Self-reported vision, Amsler, clinic-measured visual acuity (VA), fundus assessment, and spectral domain OCT. The reference standard is FFA. MAIN OUTCOME MEASURES: Sensitivity and specificity of the 5 index tests. RESULTS: Of 552 participants monitored for up to 3 years, 145 (26.3%) developed active nAMD in the study eye, of whom 120 had an FFA at detection and constituted the primary analysis cohort. Index test positives at nAMD detection in those confirmed by FFA were self-reported vision much worse (5), distortion on Amsler (33), 10-letter decrease in acuity from baseline (36), fundus examination (64), and OCT (110). Percentage index test sensitivities were: self-reported vision 4.2 (95% confidence interval [CI], 1.6-9.8); Amsler 33.7 (95% CI, 25.1-43.5); VA 30.0 (95% CI, 22.5-38.7); fundus examination 53.8 (95% CI, 44.8-62.5); and OCT 91.7 (95% CI, 85.2-95.6). All 5 index test specificities were high at 97.0 (95% CI, 94.6-98.5), 81.4 (95% CI, 76.4-85.5), 66.3 (95% CI, 61.0-71.1), 97.6 (95% CI, 95.3-98.9), and 87.8 (95% CI, 83.8-90.9), respectively. The combination of OCT with one other index test that was a secondary outcome measure increased sensitivity marginally and decreased specificity for all combinations except fundus examination. CONCLUSIONS: Tests of self-reported change in vision, unmasking of new distortion, measurements of acuity, and fundus checks to diagnose active nAMD performed poorly in contrast to OCT. Our findings support a change to guidelines in clinical practice to monitor for onset of nAMD.

Two-Year Results of the Phase 3 Randomized Controlled Study of Abicipar in Neovascular Age-Related Macular Degeneration.

PURPOSE: To report the 2-year efficacy and safety of abicipar every 8 weeks and quarterly (after initial doses) compared with monthly ranibizumab in patients with treatment-naïve neovascular age-related macular degeneration (nAMD). DESIGN: Two multicenter, randomized, phase 3 clinical trials with identical protocols (CEDAR and SEQUOIA). Analyses used pooled trial data. PARTICIPANTS: The trials enrolled 1888 patients (1 eye/patient) with active choroidal neovascularization secondary to age-related macular degeneration and best-corrected visual acuity (BCVA) of 24 to 73 Early Treatment Diabetic Retinopathy Study letters. METHODS: At enrollment, patients were assigned to study eye treatment with abicipar 2 mg every 8 weeks after initial doses at baseline and weeks 4 and 8 (abicipar Q8, n = 630), abicipar 2 mg every 12 weeks after initial doses at baseline and weeks 4 and 12 (abicipar Q12, n = 628), or ranibizumab 0.5 mg every 4 weeks (ranibizumab Q4, n = 630). MAIN OUTCOME MEASURES: Efficacy measures included stable vision (<15-letter loss in BCVA from baseline) and change from baseline in BCVA and central retinal thickness (CRT). Safety measures included adverse events (AEs). RESULTS: For patients who completed the study, efficacy of abicipar after initial doses was maintained through week 104. At week 104, the proportion of patients with stable vision was 93.0% (396/426), 89.8% (379/422), and 94.4% (470/498); mean change in BCVA from baseline was +7.8 letters, +6.1 letters, and +8.5 letters, and mean change in CRT from baseline was -147 µm, -146 µm, and -142 µm in the abicipar Q8 (14 injections), abicipar Q12 (10 injections), and ranibizumab Q4 (25 injections) groups, respectively. The overall incidence of intraocular inflammation (IOI) AEs was 15.4%, 15.3%, and 0.3% from baseline through week 52 and 16.2%, 17.6%, and 1.3% from baseline through week 104 in the abicipar Q8, abicipar Q12, and ranibizumab Q4 groups, respectively. CONCLUSIONS: Two-year results show efficacy of abicipar Q8 and Q12 in nAMD. First onset of IOI events with abicipar was much reduced in the second year and comparable with ranibizumab (0.8% and 2.3% vs. 1.0%). The extended duration of effect of abicipar allows for quarterly dosing and reduced treatment burden.

Progress in developing rodent models of age-related macular degeneration (AMD).

Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss, typically affecting individuals from mid-life onwards. Its multifactorial aetiology and the lack of any effective treatments has spurred the development of animal models as research and drug discovery tools. Several rodent models have been developed which recapitulate key features of AMD and provide insights into its underlying pathology. These have contributed to making significant progress in understanding the disease and the identification of novel therapeutic targets. However, a major caveat with existing models is that they do not demonstrate the full disease spectrum. In this review, we outline advances in rodent AMD models from the last decade. These models feature various hallmarks associated with AMD, including oxidative stress, hypoxia, immune dysregulation, genetic mutations and environmental risk factors. The review summarises the methods by which each model was created, its pathological characteristics as well as its relation to the disease in humans.

In vitro stem cell modelling demonstrates a proof-of-concept for excess functional mutant TIMP3 as the cause of Sorsby fundus dystrophy.

Sorsby fundus dystrophy (SFD) is a rare autosomal dominant disease of the macula that leads to bilateral loss of central vision and is caused by mutations in the TIMP3 gene. However, the mechanisms by which TIMP3 mutations cause SFD are poorly understood. Here, we generated human induced pluripotent stem cell-derived retinal pigmented epithelial (hiPSC-RPE) cells from three SFD patients carrying TIMP3 p.(Ser204Cys) and three non-affected controls to study disease-related structural and functional differences in the RPE. SFD-hiPSC-RPE exhibited characteristic RPE structure and physiology but showed significantly reduced transepithelial electrical resistance associated with enriched expression of cytoskeletal remodelling proteins. SFD-hiPSC-RPE exhibited basolateral accumulation of TIMP3 monomers, despite no change in TIMP3 gene expression. TIMP3 dimers were observed in both SFD and control hiPSC-RPE, suggesting that mutant TIMP3 dimerisation does not drive SFD pathology. Furthermore, mutant TIMP3 retained matrix metalloproteinase activity. Proteomic profiling showed increased expression of ECM proteins, endothelial cell interactions and angiogenesis-related pathways in SFD-hiPSC-RPE. By contrast, there were no changes in VEGF secretion. However, SFD-hiPSC-RPE secreted higher levels of monocyte chemoattractant protein 1, PDGF and angiogenin. Our findings provide a proof-of-concept that SFD patient-derived hiPSC-RPE mimic mature RPE cells and support the hypothesis that excess accumulation of mutant TIMP3, rather than an absence or deficiency of functional TIMP3, drives ECM and angiogenesis-related changes in SFD. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Epigenetic Age Acceleration Is Not Associated with Age-Related Macular Degeneration.

DNA methylation age (DNAm age) estimation is a powerful biomarker of human ageing. To date, epigenetic clocks have not been evaluated in age-related macular degeneration (AMD). Here, we perform genome-wide DNA methylation analyses in blood of AMD patients with a documented smoking history (14 AMD, 16 Normal), identifying loci of differential methylation (DML) with a relaxed p-value criterion (p ≤ 10-4). We conduct DNAm age analyses using the Horvath-multi tissue, Hannum and Skin & Blood epigenetic clocks in both blood and retinal pigment epithelium (RPE). We perform Ingenuity Pathway Analysis Causal Network Analysis (IPA CNA) on the topmost significantly differentially methylated CpG probes in blood and RPE. Results show poor performance of epigenetic clocks in RPE. Epigenetic age acceleration (EAA) was not observed in AMD. However, we observe positive EAA in blood of smokers, and in smokers with AMD. DML analysis revealed hypomethylation at cg04953735 within RPTOR (p = 6.51 × 10-5; Δß = -11.95%). IPA CNA in the RPE also identified RPTOR as the putative master regulator, predicted to be inhibited in AMD. In conclusion, this is the first study evaluating an association of epigenetic ageing in AMD. We posit a role for RPTOR as a common master regulator of methylation changes in the RPE in AMD.

Efficacy and Safety of Abicipar in Neovascular Age-Related Macular Degeneration: 52-Week Results of Phase 3 Randomized Controlled Study.

PURPOSE: To compare the efficacy and safety of abicipar every 8 weeks and quarterly (after initial doses) versus ranibizumab every 4 weeks in treatment-naïve patients with neovascular age-related macular degeneration (AMD). DESIGN: Two randomized, multicenter, double-masked, parallel-group, active-controlled, phase 3 clinical trials (CEDAR, SEQUOIA) with identical protocols were conducted. Data from both trials were pooled for analysis. PARTICIPANTS: Patients with active choroidal neovascularization secondary to AMD and best-corrected visual acuity (BCVA) of 24-73 Early Treatment Diabetic Retinopathy Study letters in the study eye were enrolled. METHODS: Patients (n = 1888) were randomized in a 1:1:1 ratio to study eye treatment with abicipar 2 mg every 8 weeks after 3 initial doses at baseline and weeks 4 and 8 (Q8), abicipar 2 mg every 12 weeks after 3 initial doses at baseline and weeks 4 and 12 (Q12), or ranibizumab 0.5 mg every 4 weeks (Q4). MAIN OUTCOME MEASURES: The primary efficacy end point was proportion of patients with stable vision (defined as <15-letter loss in BCVA from baseline) in the study eye at week 52. Secondary end points included change from baseline in BCVA and central retinal thickness (CRT) at week 52. Safety measures included adverse events (AEs). RESULTS: The proportion of patients with stable vision at week 52 was 93.2%, 91.3%, and 95.8% in the abicipar Q8, abicipar Q12, and ranibizumab Q4 groups, respectively, with both abicipar Q8 and Q12 noninferior to ranibizumab Q4. Week 52 mean change from baseline in BCVA was 7.5, 6.4, and 8.4 letters and in CRT was -144, -145, and -144 µm in the abicipar Q8, abicipar Q12, and ranibizumab Q4 groups, respectively. Incidence of intraocular inflammation (IOI) AEs was 15.4%, 15.3%, and 0.3%, respectively. The IOI AEs were typically mild or moderate in severity and treated with topical corticosteroids; 62 of 192 patients (32.3%) received oral and/or injectable corticosteroids. CONCLUSIONS: Abicipar Q8 and Q12 were both noninferior to ranibizumab Q4 in the primary end point of stable vision at week 52. Intraocular inflammation was more frequent with abicipar. Quarterly and Q8 abicipar reduce nAMD disease and treatment burden compared with monthly treatment.

An Intraocular Pressure Polygenic Risk Score Stratifies Multiple Primary Open-Angle Glaucoma Parameters Including Treatment Intensity.

PURPOSE: To examine the combined effects of common genetic variants associated with intraocular pressure (IOP) on primary open-angle glaucoma (POAG) phenotype using a polygenic risk score (PRS) stratification. DESIGN: Cross-sectional study. PARTICIPANTS: For the primary analysis, we examined the glaucoma phenotype of 2154 POAG patients enrolled in the Australian and New Zealand Registry of Advanced Glaucoma, including patients recruited from the United Kingdom. For replication, we examined an independent cohort of 624 early POAG patients. METHODS: Using IOP genome-wide association study summary statistics, we developed a PRS derived solely from IOP-associated variants and stratified POAG patients into 3 risk tiers. The lowest and highest quintiles of the score were set as the low- and high-risk groups, respectively, and the other quintiles were set as the intermediate risk group. MAIN OUTCOME MEASURES: Clinical glaucoma phenotype including maximum recorded IOP, age at diagnosis, number of family members affected by glaucoma, cup-to-disc ratio, visual field mean deviation, and treatment intensity. RESULTS: A dose-response relationship was found between the IOP PRS and the maximum recorded IOP, with the high genetic risk group having a higher maximum IOP by 1.7 mmHg (standard deviation [SD], 0.62 mmHg) than the low genetic risk group (P = 0.006). Compared with the low genetic risk group, the high genetic risk group had a younger age of diagnosis by 3.7 years (SD, 1.0 years; P < 0.001), more family members affected by 0.46 members (SD, 0.11 members; P < 0.001), and higher rates of incisional surgery (odds ratio, 1.5; 95% confidence interval, 1.1-2.0; P = 0.007). No statistically significant difference was found in mean deviation. We further replicated the maximum IOP, number of family members affected by glaucoma, and treatment intensity (number of medications) results in the early POAG cohort (P ≤ 0.01). CONCLUSIONS: The IOP PRS was correlated positively with maximum IOP, disease severity, need for surgery, and number of affected family members. Genes acting via IOP-mediated pathways, when considered in aggregate, have clinically important and reproducible implications for glaucoma patients and their close family members.