Preclinical Development of Antisense Oligonucleotides to Rescue Aberrant Splicing Caused by an Ultrarare ABCA4 Variant in a Child with Early-Onset Stargardt Disease.

Precision medicine is rapidly gaining recognition in the field of (ultra)rare conditions, where only a few individuals in the world are affected. Clinical trial design for a small number of patients is extremely challenging, and for this reason, the development of N-of-1 strategies is explored to accelerate customized therapy design for rare cases. A strong candidate for this approach is Stargardt disease (STGD1), an autosomal recessive macular degeneration characterized by high genetic and phenotypic heterogeneity. STGD1 is caused by pathogenic variants in ABCA4, and amongst them, several deep-intronic variants alter the pre-mRNA splicing process, generally resulting in the insertion of pseudoexons (PEs) into the final transcript. In this study, we describe a 10-year-old girl harboring the unique deep-intronic ABCA4 variant c.6817-713A>G. Clinically, she presents with typical early-onset STGD1 with a high disease symmetry between her two eyes. Molecularly, we designed antisense oligonucleotides (AONs) to block the produced PE insertion. Splicing rescue was assessed in three different in vitro models: HEK293T cells, fibroblasts, and photoreceptor precursor cells, the last two being derived from the patient. Overall, our research is intended to serve as the basis for a personalized N-of-1 AON-based treatment to stop early vision loss in this patient.

Towards Uncovering the Role of Incomplete Penetrance in Maculopathies through Sequencing of 105 Disease-Associated Genes.

Inherited macular dystrophies (iMDs) are a group of genetic disorders, which affect the central region of the retina. To investigate the genetic basis of iMDs, we used single-molecule Molecular Inversion Probes to sequence 105 maculopathy-associated genes in 1352 patients diagnosed with iMDs. Within this cohort, 39.8% of patients were considered genetically explained by 460 different variants in 49 distinct genes of which 73 were novel variants, with some affecting splicing. The top five most frequent causative genes were ABCA4 (37.2%), PRPH2 (6.7%), CDHR1 (6.1%), PROM1 (4.3%) and RP1L1 (3.1%). Interestingly, variants with incomplete penetrance were revealed in almost one-third of patients considered solved (28.1%), and therefore, a proportion of patients may not be explained solely by the variants reported. This includes eight previously reported variants with incomplete penetrance in addition to CDHR1:c.783G>A and CNGB3:c.1208G>A. Notably, segregation analysis was not routinely performed for variant phasing-a limitation, which may also impact the overall diagnostic yield. The relatively high proportion of probands without any putative causal variant (60.2%) highlights the need to explore variants with incomplete penetrance, the potential modifiers of disease and the genetic overlap between iMDs and age-related macular degeneration. Our results provide valuable insights into the genetic landscape of iMDs and warrant future exploration to determine the involvement of other maculopathy genes.

Genome-wide characterization of circulating metabolic biomarkers.

Genome-wide association analyses using high-throughput metabolomics platforms have led to novel insights into the biology of human metabolism1-7. This detailed knowledge of the genetic determinants of systemic metabolism has been pivotal for uncovering how genetic pathways influence biological mechanisms and complex diseases8-11. Here we present a genome-wide association study for 233 circulating metabolic traits quantified by nuclear magnetic resonance spectroscopy in up to 136,016 participants from 33 cohorts. We identify more than 400 independent loci and assign probable causal genes at two-thirds of these using manual curation of plausible biological candidates. We highlight the importance of sample and participant characteristics that can have significant effects on genetic associations. We use detailed metabolic profiling of lipoprotein- and lipid-associated variants to better characterize how known lipid loci and novel loci affect lipoprotein metabolism at a granular level. We demonstrate the translational utility of comprehensively phenotyped molecular data, characterizing the metabolic associations of intrahepatic cholestasis of pregnancy. Finally, we observe substantial genetic pleiotropy for multiple metabolic pathways and illustrate the importance of careful instrument selection in Mendelian randomization analysis, revealing a putative causal relationship between acetone and hypertension. Our publicly available results provide a foundational resource for the community to examine the role of metabolism across diverse diseases.

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 it 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) 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.

Study of Late-Onset Stargardt Type 1 Disease: Characteristics, Genetics, and Progression.

PURPOSE: Late-onset Stargardt disease is a subtype of Stargardt disease type 1 (STGD1), defined by an age of onset of 45 years or older. We describe the disease characteristics, underlying genetics, and disease progression of late-onset STGD1 and highlight the differences from geographic atrophy. DESIGN: Retrospective cohort study. PARTICIPANTS: Seventy-one patients with late-onset STGD1. METHODS: Medical files were reviewed for clinical data including age at onset, initial symptoms, and best-corrected visual acuity. A quantitative and qualitative assessment of retinal pigment epithelium (RPE) atrophy was performed on fundus autofluorescence images and OCT scans. MAIN OUTCOME MEASURES: Age at onset, genotype, visual acuity, atrophy growth rates, and loss of external limiting membrane, ellipsoid zone, and RPE. RESULTS: Median age at onset was 55.0 years (range, 45-82 years). A combination of a mild and severe variant in ATP-binding cassette subfamily A member 4 (ABCA4) was the most common genotype (n = 49 [69.0%]). The most frequent allele, c.5603A→T (p.Asn1868Ile), was present in 43 of 71 patients (60.6%). No combination of 2 severe variants was found. At first presentation, all patients have flecks. Foveal-sparing atrophy was present in 33.3% of eyes, whereas 21.1% had atrophy with foveal involvement. Extrafoveal atrophy was present in 38.9% of eyes, and no atrophy was evident in 6.7% of eyes. Time-to-event curves showed a median duration of 15.4 years (95% confidence interval, 11.1-19.6 years) from onset to foveal involvement. The median visual acuity decline was -0.03 Snellen decimal per year (interquartile range [IQR], -0.07 to 0.00 Snellen decimal; 0.03 logarithm of the minimum angle of resolution). Median atrophy growth was 0.590 mm2/year (IQR, 0.046-1.641 mm2/year) for definitely decreased autofluorescence and 0.650 mm2/year (IQR, 0.299-1.729 mm2/year) for total decreased autofluorescence. CONCLUSIONS: Late-onset STGD1 is a subtype of STGD1 with most commonly 1 severe and 1 mild ABCA4 variant. The general patient presents with typical fundus flecks and retinal atrophy in a foveal-sparing pattern with preserved central vision. Misdiagnosis as age-related macular degeneration should be avoided to prevent futile invasive treatments with potential complications. In addition, correct diagnosis lends patients with late-onset STGD1 the opportunity to participate in potentially beneficial therapeutic trials for STGD1. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Efficacy of Carbonic Anhydrase Inhibitors on Cystoid Fluid Collections and Visual Acuity in Patients with X-Linked Retinoschisis.

PURPOSE: To date, there is no standard treatment regimen for carbonic anhydrase inhibitors (CAIs) in X-linked retinoschisis (XLRS) patients. This retrospective study aims to evaluate the efficacy of CAIs on visual acuity and cystoid fluid collections (CFC) in XRLS patients in Dutch and Belgian tertiary referral centers. DESIGN: Retrospective cohort study. PARTICIPANTS: Forty-two patients with XLRS. METHODS: In total, 42 patients were enrolled. To be included, patients had to have previous treatment with an oral CAI (acetazolamide), a topical CAI (brinzolamide/dorzolamide), or a combination of an oral and a topical CAI for at least 4 consecutive weeks. We evaluated the effect of the CAI on best-corrected visual acuity (BCVA) and central foveal thickness (CFT) on OCT. MAIN OUTCOME MEASURES: Central foveal thickness and BCVA. RESULTS: The median age at the baseline visit of the patients in this cohort study was 14.7 (range, 43.6) years, with a median (interquartile range [IQR]) follow-up period of 4.0 (2.2-5.2) years. During the follow-up period, 25 patients were treated once with an oral CAI (60%), 24 patients were treated once with a topical CAI (57%), and 11 patients were treated once with a combination of both topical and oral CAI (26%). We observed a significant reduction of CFT for oral CAI by 14.37 µm per 100 mg per day (P < 0.001; 95% confidence interval [CI], -19.62 to -9.10 µm) and for topical CAI by 7.52 µm per drop per day (P = 0.017; 95% CI, -13.67 to -1.32 µm). The visual acuity changed significantly while on treatment with oral CAI by -0.0059 logMAR per 100 mg (P = 0.008; 95% CI, -0.010 to -0.0013 logMAR). Seven patients (17%) had side effects leading to treatment discontinuation. CONCLUSIONS: Our data indicate that treatment with (oral) CAI may be beneficial for short-term management of CFC in patients with XLRS. Despite a significant reduction in CFT, the change in visual acuity was modest and not of clinical significance. Nonetheless, the anatomic improvement of the central retina in these patients may be of value to create an optimal retinal condition for future potential treatment options such as gene therapy. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Functional Vision in Patients With Biallelic USH2A Variants.

PURPOSE: To describe functional vision (FV) and investigate the relationship between FV, visual acuity (VA), and hill of vision (VTOT) at baseline in patients with biallelic USH2A variants. DESIGN: Multicenter, international, cross-sectional study. METHODS: In individuals with biallelic disease-causing variants in USH2A, clinical diagnosis of Usher syndrome type 2 (USH2) or autosomal recessive nonsyndromic retinitis pigmentosa (ARRP) was based on history of hearing loss and audiology examinations. The VALVVFQ-48 was administered verbally to participants ≥18 years old. VA was measured in both eyes; VTOT was determined from static perimetry in the study eye (better VA). FV scores were calculated using Rasch analysis. RESULTS: Median age of 121 participants (76 with USH2, 45 with ARRP) was 41 years (range: 19-80); 54% were female. FV scores varied from -2.0 to 7.6 logits (median [interquartile range (IQR)]: 2.8 [1.5-3.8]). ARRP and USH2 participants had similar FV scores, both before [mean (95% CI): 2.8 (2.3-3.4) and 2.7 (2.3-3.2), respectively], and after [mean (95% CI): 2.5 (2.1-3.0) and 2.9 (2.6-3.3), respectively; P = .24] adjusting for age, VA, disease duration, and VTOT. VA and VTOT accounted for 29% and 26% of the variance in FV scores, respectively (P < .001 for each). Together, they accounted for 36% of variance observed. CONCLUSIONS: Biallelic USH2A variants were associated with a large range of FV, yet similar in ARRP and USH2, despite hearing loss in USH2. The modified VALVVFQ-48 we evaluated is not ideal for detecting the impact of USH2A-associated retinal degenerations on activities of daily living.

Generation of an iPSC line (RMCGENi020-A) from a patient with Stargardt disease harboring the recurrent intronic ABCA4 variant c.4253+43G>A.

Pathogenic variants in ABCA4 are associated with Stargardt disease (STGD1), an autosomal recessive macular dystrophy characterized by bilateral central vision loss due to a progressive degeneration of retinal cells. An induced pluripotent stem cell (iPSC) line was generated from late-onset STGD1 patient-derived fibroblasts harboring bi-allelic ABCA4 variants by lentivirus-induced reprogramming. The obtained iPSC line (RMCGENi020-A) showed pluripotent features after the reprogramming process. The generation of this iPSC line facilitates its use to differentiate it into relevant retinal-like cell models, with the aim to adequately evaluate the effects of the ABCA4 variants.

Targeted sequencing and in vitro splice assays shed light on ABCA4-associated retinopathies missing heritability.

The ABCA4 gene is the most frequently mutated Mendelian retinopathy-associated gene. Biallelic variants lead to a variety of phenotypes, however, for thousands of cases the underlying variants remain unknown. Here, we aim to shed further light on the missing heritability of ABCA4-associated retinopathy by analyzing a large cohort of macular dystrophy probands. A total of 858 probands were collected from 26 centers, of whom 722 carried no or one pathogenic ABCA4 variant, while 136 cases carried two ABCA4 alleles, one of which was a frequent mild variant, suggesting that deep-intronic variants (DIVs) or other cis-modifiers might have been missed. After single molecule molecular inversion probes (smMIPs)-based sequencing of the complete 128-kb ABCA4 locus, the effect of putative splice variants was assessed in vitro by midigene splice assays in HEK293T cells. The breakpoints of copy number variants (CNVs) were determined by junction PCR and Sanger sequencing. ABCA4 sequence analysis solved 207 of 520 (39.8%) naive or unsolved cases and 70 of 202 (34.7%) monoallelic cases, while additional causal variants were identified in 54 of 136 (39.7%) probands carrying two variants. Seven novel DIVs and six novel non-canonical splice site variants were detected in a total of 35 alleles and characterized, including the c.6283-321C>G variant leading to a complex splicing defect. Additionally, four novel CNVs were identified and characterized in five alleles. These results confirm that smMIPs-based sequencing of the complete ABCA4 gene provides a cost-effective method to genetically solve retinopathy cases and that several rare structural and splice altering defects remain undiscovered in Stargardt disease cases.

Quality of life in patients with CRB1-associated retinal dystrophies: A longitudinal study.

PURPOSE: To assess the longitudinal vision-related quality of life among patients with CRB1-associated inherited retinal dystrophies. METHODS: In this longitudinal questionnaire study, the National Eye Institute Visual Function Questionnaire (39 items, NEI VFQ-39) was applied at baseline, two-year follow-up, and 4-year follow-up in patients with pathogenic CRB1 variants. [Correction added on 20 November 2023, after first online publication: The preceding sentence has been updated in this version.] Classical test theory was performed to obtain subdomain scores and in particular 'near activities' and 'total composite' scores. The Rasch analysis based on previous calibrations of the NEI VFQ-25 was applied to create visual functioning and socio-emotional subscales. RESULTS: In total, 22 patients with a CRB1-associated retinal dystrophy were included, […] with a median age of 25.0 years (interquartile range: 13-31 years) at baseline and mean follow-up of 4.0 ± 0.3 years. [Correction added on 20 November 2023, after first online publication: The preceding sentence has been updated in this version.] A significant decline at 4 years was observed for 'near activities' (51.0 ± 23.8 vs 35.4 ± 14.7, p = 0.004) and 'total composite' (63.0 ± 13.1 vs 52.0 ± 12.1, p = 0.001) subdomain scores. For the Rasch-scaled scores, the 'visual functioning' scale significantly decreased after 2 years (-0.89 logits; p = 0.012), but not at 4-year follow-up (+0.01 logits; p = 0.975). [Correction added on 20 November 2023, after first online publication: In the preceding sentence, "…after 4 years…" has been corrected to "…after 2 years…" in this version.] The 'socio-emotional' scale also showed a significant decline after 2 years (-0.78 logits, p = 0.033) and 4 years (-0.83 logits, p = 0.021). CONCLUSION: In the absence of an intervention, a decline in vision-related quality of life is present in patients with pathogenic CRB1 variants at 4-year follow-up. Patient-reported outcome measures should be included in future clinical trials, as they can be a potential indicator of disease progression and treatment efficacy.

Interaction between genetics and the adherence to the Mediterranean diet: the risk for age-related macular degeneration. Coimbra Eye Study Report 8.

BACKGROUND: Age-related macular degeneration (AMD) is a multifactorial degenerative disease of the macula. Different factors, environmental, genetic and lifestyle, contribute to its onset and progression. However, how they interconnect to promote the disease, or its progression, is still unclear. With this work, we aim to assess the interaction of the genetic risk for AMD and the adherence to the Mediterranean diet in the Coimbra Eye Study. METHODS: Enrolled subjects (n = 612) underwent ophthalmological exams and answered a food questionnaire. Adherence to the Mediterranean diet was assessed with mediSCORE. An overall value was calculated for each participant, ranging from 0 to 9, using the sum of 9 food groups, and a cut off value of ≥ 6 was considered high adherence. Rotterdam Classification was used for grading. Participants' genotyping was performed in collaboration with The European Eye Epidemiology Consortium. The genetic risk score (GRS) was calculated for each participant considering the number of alleles at each variant and their effect size. Interaction was assessed with additive and multiplicative models, adjusted for age, sex, physical exercise, and smoking. RESULTS: The AMD risk was reduced by 60% in subjects with high adherence to the Mediterranean diet compared to subjects with low adherence to the Mediterranean diet. Combined effects of having low adherence to the Mediterranean diet and high GRS led to almost a 5-fold increase in the risk for AMD, compared to low GRS and high adherence to the Mediterranean diet. The multiplicative scale suggested a multiplicative interaction, although not statistically significant [odds ratio (OR) = 1.111, 95% CI 0.346-3.569, P = 0.859]. The additive model showed a causal positive effect of the interaction of GRS and adherence to the Mediterranean diet: relative excess risk due to interaction (RERI) = 150.9%, (95% CI: - 0.414 to 3.432, P = 0.062), attributable proportion due to interaction (AP) = 0.326 (95% CI: - 0.074 to 0.726, P = 0.055) and synergy index (SI) = 1.713 (95% CI: 0.098-3.329, P = 0.019). High GRS people benefited from adhering to the Mediterranean diet with a 60% risk reduction. For low-GRS subjects, a risk reduction was also seen, but not significantly. CONCLUSIONS: Genetics and Mediterranean diet interact to protect against AMD, proving there is an interplay between genetics and environmental factors. TRIAL REGISTRATION: The AMD Incidence (NCT02748824) and Lifestyle and Food Habits Questionnaire in the Portuguese Population Aged 55 or More (NCT01715870) studies are registered at www. CLINICALTRIALS: gov . Five-year Incidence of Age-related Macular Degeneration in the Central Region of Portugal (AMD IncidencePT); NCT02748824: date of registration: 22/04/16. Lifestyle and Food Habits Questionnaire in the Portuguese Population Aged 55 or More; NCT01715870: date of registration: 29/10/12.

Generation of iPSC lines from three Stargardt patients carrying bi-allelic ABCA4 variants.

Stargardt disease, a progressive retinal disorder, is associated with bi-allelic variants in ABCA4, a protein that is expressed in the retina. Induced pluripotent stem cell lines (RMCGENi005-A, SCTCi018-A, SCTCi017-A) were generated by lentivirus reprogramming of fibroblasts derived from Stargardt patients carrying different bi-allelic ABCA4 variants. All the generated lines showed pluripotent characteristics and no chromosomal aberrations. The availability of these lines will allow us to generate patient-derived photoreceptor precursor cells and retinal organoids to further study ABCA4 and thereby, Stargardt disease in relevant model systems carrying the patient's genetic background.

Association of Risk Variants in the CFH Gene With Elevated Levels of Coagulation and Complement Factors in Idiopathic Multifocal Choroiditis.

Importance: Idiopathic multifocal choroiditis (MFC) is poorly understood, thereby hindering optimal treatment and monitoring of patients. Objective: To identify the genes and pathways associated with idiopathic MFC. Design, Setting, and Participants: This was a case-control genome-wide association study (GWAS) and protein study of blood plasma samples conducted from March 2006 to February 2022. This was a multicenter study involving 6 Dutch universities. Participants were grouped into 2 cohorts: cohort 1 consisted of Dutch patients with idiopathic MFC and controls, and cohort 2 consisted of patients with MFC and controls. Plasma samples from patients with idiopathic MFC who had not received treatment were subjected to targeted proteomics. Idiopathic MFC was diagnosed according to the Standardization of Uveitis Nomenclature (SUN) Working Group guidelines for punctate inner choroidopathy and multifocal choroiditis with panuveitis. Data were analyzed from July 2021 to October 2022. Main outcomes and measures: Genetic variants associated with idiopathic MFC and risk variants associated with plasma protein concentrations in patients. Results: This study included a total of 4437 participants in cohort 1 (170 [3.8%] Dutch patients with idiopathic MFC and 4267 [96.2%] controls; mean [SD] age, 55 [18] years; 2443 female [55%]) and 1344 participants in cohort 2 (52 [3.9%] patients with MFC and 1292 [96.1%] controls; 737 male [55%]). The primary GWAS association mapped to the CFH gene with genome-wide significance (lead variant the A allele of rs7535263; odds ratio [OR], 0.52; 95% CI, 0.41-0.64; P = 9.3 × 10-9). There was no genome-wide significant association with classical human leukocyte antigen (HLA) alleles (lead classical allele, HLA-A*31:01; P = .002). The association with rs7535263 showed consistent direction of effect in an independent cohort of 52 cases and 1292 control samples (combined meta-analysis OR, 0.58; 95% CI, 0.38-0.77; P = 3.0 × 10-8). In proteomic analysis of 87 patients, the risk allele G of rs7535263 in the CFH gene was strongly associated with increased plasma concentrations of factor H-related (FHR) proteins (eg, FHR-2, likelihood ratio test, adjusted P = 1.1 × 10-3) and proteins involved in platelet activation and the complement cascade. Conclusions and relevance: Results suggest that CFH gene variants increase systemic concentrations of key factors of the complement and coagulation cascades, thereby conferring susceptibility to idiopathic MFC. These findings suggest that the complement and coagulation pathways may be key targets for the treatment of idiopathic MFC.

Evaluation of Sleep Quality and Fatigue in Patients with Usher Syndrome Type 2a.

Purpose: To study the prevalence, level, and nature of sleep problems and fatigue experienced by Usher syndrome type 2a (USH2a) patients. Design: Cross-sectional study. Participants: Fifty-six genetically confirmed Dutch patients with syndromic USH2a and 120 healthy controls. Methods: Sleep quality, prevalence, and type of sleep disorders, chronotype, fatigue, and daytime sleepiness were assessed using 5 questionnaires: (1) Pittsburgh Sleep Quality Index, (2) Holland Sleep Disorders Questionnaire, (3) Morningness-Eveningness Questionnaire, (4) Checklist Individual Strength, and (5) Epworth Sleepiness Scale. For a subset of patients, recent data on visual function were used to study the potential correlation between the outcomes of the questionnaires and disease progression. Main Outcome Measures: Results of all questionnaires were compared between USH2a and control cohorts, and the scores of the patients were compared with disease progression defined by age, visual field size, and visual acuity. Results: Compared with the control population, patients with USH2a experienced a poorer quality of sleep, a higher incidence of sleep disorders, and higher levels of fatigue and daytime sleepiness. Intriguingly, the sleep disturbances and high levels of fatigue were not correlated with the level of visual impairment. These results are in accordance with the patients' experiences that their sleep problems already existed before the onset of vision loss. Conclusions: This study demonstrates a high prevalence of fatigue and poor sleep quality experienced by patients with USH2a. Recognition of sleep problems as a comorbidity of Usher syndrome would be a first step toward improved patient care. The absence of a relationship between the level of visual impairment and the severity of reported sleep problems is suggestive of an extraretinal origin of the sleep disturbances. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Systemic Metabolomics in a Framework of Genetics and Lifestyle in Age-Related Macular Degeneration.

Insights into the pathogenesis of age-related macular degeneration (AMD), a leading cause of blindness, point towards a complex interplay of genetic and lifestyle factors triggering various systemic pathways. This study aimed to characterize metabolomic profiles for AMD and to evaluate their position in the trias with genetics and lifestyle. This study included 5923 individuals from five European studies. Blood metabolomics were assessed using a nuclear magnetic resonance platform of 146 metabolites. Associations were studied using regression analyses. A genetic risk score (GRS) was calculated using ß-values of 49 AMD variants, a lifestyle risk score (LRS) using smoking and diet data, and a metabolite risk score (MRS) using metabolite values. We identified 61 metabolites associated with early-intermediate AMD, of which 94% were lipid-related, with higher levels of HDL-subparticles and apolipoprotein-A1, and lower levels of VLDL-subparticles, triglycerides, and fatty acids (false discovery rate (FDR) p-value < 1.4 × 10-2). Late AMD was associated with lower levels of the amino acids histidine, leucine, valine, tyrosine, and phenylalanine, and higher levels of the ketone bodies acetoacetate and 3-hydroxybutyrate (FDR p-value < 1.5 × 10-3). A favorable lifestyle characterized by a healthy diet was associated with higher levels of amino acids and lower levels of ketone bodies, while an unfavorable lifestyle, including smoking, showed opposite effects (FDR p-value < 2.7 × 10-2). The MRS mediated 5% of the effect of the GRS and 20% of that of the LRS on late AMD. Our findings show that metabolomic profiles differ between AMD stages and show that blood metabolites mostly reflect lifestyle. The severity-specific profiles spur further interest into the systemic effects related to disease conversion.

Fundus autofluorescence abnormalities can predict fluorescein angiography abnormalities in patients with chronic central serous chorioretinopathy.

PURPOSE: This study is to assess the possible correlation between findings on fundus autofluorescence (FAF) and fluorescein angiography (FA) in patients with chronic central serous chorioretinopathy (cCSC). METHODS: This multicentre retrospective cohort study included 71 cCSC patients (92 eyes) with at least 6 months of follow-up, who had a FAF-FA imaging discrepancy larger than 0.5 optic disc diameters in size in the corresponding areas of hyperfluorescent abnormalities. A comparison was performed between progression in size of areas of hyperautofluorescent retinal pigment epithelium (RPE) abnormalities on FAF (HF-FAF) and the hyperfluorescent areas on FA (HF-FA) at first visit and last visit. The possible correlations were estimated between FAF-FA discrepancy and disease characteristics. RESULTS: The median area of HF-FAF at first visit was 7.48 mm2 (1.41-27.9). The median area of HF-FA at first visit and last visit was 2.40 mm2 (0.02-17.27) and 5.22 mm2 (0.53-25.62), respectively. FAF-FA discrepancy was associated with follow-up duration and the area of HF-FAF at first visit. A mathematical algorithm for grading FAF-FA discrepancy in time was suggested, which predicted the enlargement of hyperfluorescent RPE abnormalities on FA in 82.6% of cases. CONCLUSION: There is a statistically significant relationship between the areas of HF-FAF and HF-FA in cCSC patients with FAF-FA imaging discrepancy at first presentation. Long-term changes in RPE alterations in cCSC on FA can be predicted based on baseline HF-FAF and follow-up duration.

Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction.

A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.

INCREASING EVIDENCE FOR THE SAFETY OF FOVEA-INVOLVING HALF-DOSE PHOTODYNAMIC THERAPY FOR CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: A retrospective study was performed with data from the prospective randomized controlled trials, PLACE and SPECTRA, assessing the risk of foveal atrophy and the likelihood of structural and functional improvement on optical coherence tomography, after foveal half-dose photodynamic therapy in chronic central serous chorioretinopathy. METHODS: A total of 57 chronic central serous chorioretinopathy patients received a single half-dose photodynamic therapy with a treatment spot that included the fovea. Optical coherence tomography scans and fundus autofluorescence images were analyzed for structural improvement and possible atrophy development, at baseline and at several visits after treatment. Main outcome measures were integrity of the external limiting membrane and ellipsoid zone on optical coherence tomography and hypoautofluorescence on fundus autofluorescence. RESULTS: The subfoveal external limiting membrane was graded as continuous in 21 of 57 of patients (36.8%) at baseline, and the subfoveal ellipsoid zone was graded as continuous in 5 of 57 patients (8.8%) at first visit, which improved to 50 of 51 (98.0%) and 32 out of 51 (62.7%) at the final visit at 2 years, respectively (both P < 0.001). Hypoautofluorescent changes on fundus autofluorescence were present in 25 of 55 patients (45.5%) at baseline and in 23 of 51 patients (45.1%) at the final visit ( P = 0.480). CONCLUSION: In patients with chronic central serous chorioretinopathy who received a single, foveal, half-dose photodynamic therapy, a significant improvement in structure and function was seen at the final follow-up. None of the patients developed foveal atrophy.

Repeatability of Quantitative Autofluorescence Imaging in a Multicenter Study Involving Patients With Recessive Stargardt Disease 1.

Purpose: This study assesses the repeatability of quantitative autofluorescence (qAF) in a multicenter setting and evaluates qAF as the end point for clinical trials in recessive Stargardt disease 1 (STGD1). Methods: A total of 102 patients with STGD1 underwent qAF imaging as part of the Stargardt Remofuscin Treatment Trial (STARTT; EudraCT No. 2018-001496-20). For 166 eyes, we obtained qAF imaging at 2 visits, with 2 recordings per visit. The qAF8 values were independently determined by the study site and a central reading center. Intra- and inter-visit reproducibility, as well as interobserver (study site versus reading center) reproducibility were obtained using intraclass correlation (ICC), one-sample t-test, and Bland-Altman coefficient of repeatability. Results: The qAF repeatability was ± 26.1% for intra-visit, ± 40.5% for inter-visit, and ± 20.2% for the interobserver reproducibility measures. Intra-visit repeatability was good to excellent for all sites (ICC of 0.88-0.96). Variability between visits was higher with an overall ICC of 0.76 (0.69-0.81). We observed no significant difference in qAF values across sites between visits (7.06 ± 93.33, P = 0.238). Conclusions: Real-life test-retest variability of qAF is higher in this set of data than previously reported in single center settings. With improved operator training and by selecting the better of two recordings for evaluation, qAF serves as a useful method for assessing changes in autofluorescence signal. Translational Relevance: The qAF can be adopted as a clinical trial end point, but steps to counterbalance variability should be considered.