Retinal Dystrophies Associated With Peripherin-2: Genetic Spectrum and Novel Clinical Observations in 241 Patients.

Purpose: To describe the clinical, electrophysiological and genetic spectrum of inherited retinal diseases associated with variants in the PRPH2 gene. Methods: A total of 241 patients from 168 families across 15 sites in 9 countries with pathogenic or likely pathogenic variants in PRPH2 were included. Records were reviewed for age at symptom onset, visual acuity, full-field ERG, fundus colour photography, fundus autofluorescence (FAF), and SD-OCT. Images were graded into six phenotypes. Statistical analyses were performed to determine genotype-phenotype correlations. Results: The median age at symptom onset was 40 years (range, 4-78 years). FAF phenotypes included normal (5%), butterfly pattern dystrophy, or vitelliform macular dystrophy (11%), central areolar choroidal dystrophy (28%), pseudo-Stargardt pattern dystrophy (41%), and retinitis pigmentosa (25%). Symptom onset was earlier in retinitis pigmentosa as compared with pseudo-Stargardt pattern dystrophy (34 vs 44 years; P = 0.004). The median visual acuity was 0.18 logMAR (interquartile range, 0-0.54 logMAR) and 0.18 logMAR (interquartile range 0-0.42 logMAR) in the right and left eyes, respectively. ERG showed a significantly reduced amplitude across all components (P < 0.001) and a peak time delay in the light-adapted 30-Hz flicker and single-flash b-wave (P < 0.001). Twenty-two variants were novel. The central areolar choroidal dystrophy phenotype was associated with 13 missense variants. The remaining variants showed marked phenotypic variability. Conclusions: We described six distinct FAF phenotypes associated with variants in the PRPH2 gene. One FAF phenotype may have multiple ERG phenotypes, demonstrating a discordance between structure and function. Given the vast spectrum of PRPH2 disease our findings are useful for future clinical trials.

Mitochondrial retinopathies and optic neuropathies: The impact of retinal imaging on modern understanding of pathogenesis, diagnosis, and management.

Advancements in ocular imaging have significantly broadened our comprehension of mitochondrial retinopathies and optic neuropathies by examining the structural and pathological aspects of the retina and optic nerve in these conditions. This article aims to review the prominent imaging characteristics associated with mitochondrial retinopathies and optic neuropathies, aiming to deepen our insight into their pathogenesis and clinical features. Preceding this exploration, the article provides a detailed overview of the crucial genetic and clinical features, which is essential for the proper interpretation of in vivo imaging. More importantly, we will provide a critical analysis on how these imaging modalities could serve as biomarkers for characterization and monitoring, as well as in guiding treatment decisions. However, these imaging methods have limitations, which will be discussed along with potential strategies to mitigate them. Lastly, the article will emphasize the potential advantages and future integration of imaging techniques in evaluating patients with mitochondrial eye disorders, considering the prospects of emerging gene therapies.

Systematic study of ophthalmological findings in 10 patients with PEX1-mediated Zellweger spectrum disorder.

PURPOSE: This cross-sectional study describes the ophthalmological and general phenotype of 10 patients from six different families with a comparatively mild form of Zellweger spectrum disorder (ZSD), a rare peroxisomal disorder. METHODS: Ophthalmological assessment included best-corrected visual acuity (BCVA), perimetry, microperimetry, ophthalmoscopy, fundus photography, spectral-domain optical coherence tomography (SD-OCT), and fundus autofluorescence (FAF) imaging. Medical records were reviewed for medical history and systemic manifestations of ZSD. RESULTS: Nine patients were homozygous for c.2528 G > A (p.Gly843Asp) variants in PEX1 and one patient was compound heterozygous for c.2528 G>A (p.Gly843Asp) and c.2097_2098insT (p.Ile700TyrfsTer42) in PEX1. Median age was 22.6 years (interquartile range (IQR): 15.9 - 29.9 years) at the most recent examination, with a median symptom duration of 22.1 years. Symptom onset was variable with presentations of hearing loss (n = 7) or nyctalopia/reduced visual acuity (n = 3) at a median age of 6 months (IQR: 1.9-8.3 months). BCVA (median of 0.8 logMAR; IQR: 0.6-0.9 logMAR) remained stable over 10.8 years and all patients were hyperopic. Fundus examination revealed a variable retinitis pigmentosa (RP)-like phenotype with rounded hyperpigmentations as most prominent feature in six out of nine patients. Electroretinography, visual field measurements, and microperimetry further established the RP-like phenotype. Multimodal imaging revealed significant intraretinal fluid cavities on SD-OCT and a remarkable pattern of hyperautofluorescent abnormalities on FAF in all patients. CONCLUSION: This study highlights the ophthalmological phenotype resembling RP with moderate to severe visual impairment in patients with mild ZSD. These findings can aid ophthalmologists in diagnosing, counselling, and managing patients with mild ZSD.

Choroidal hyperpermeability patterns correlate with disease severity in central serous chorioretinopathy: CERTAIN study report 2.

PURPOSE: Choroidal vascular hyperpermeability (CVH) on indocyanine green angiography (ICGA) is a hallmark feature of central serous chorioretinopathy (CSC). We identified three distinct CVH phenotypes in CSC: uni-focal indistinct signs of choroidal hyperpermeability (uni-FISH) with one focal area of CVH, multiple areas of focal CVH (multi-FISH), and diffuse hyperpermeability covering most of the posterior pole (DISH). This report investigates the distribution of these phenotypes and their association with signs of disease chronicity. METHODS: The CERTAIN study is a monocentric, retrospective study on consecutive CSC patients referred to a large tertiary referral centre that underwent ultra-widefield (UWF) and 55° ICGA. Two independent graders assessed CVH patterns based on mid- to late-phase UWF and 55° ICGA with a third grader acting as referee. RESULTS: Of the 167 eyes of 91 patients included in this study, 43 (26%) showed uni-FISH, 87 (52%) multi-FISH, and 34 (20%) showed DISH based on UWF ICGA. Median age (40 vs. 45 vs. 57; p < 0.001) and logMAR visual acuity (0 vs. 0 vs. 0.1, p < 0.001) differed significantly in-between groups, as did the occurrence of cystoid retinal degeneration (PCRD; 0% vs. 1% vs. 18%, p < 0.001) or diffuse atrophic RPE alterations (DARA; 0% vs. 17% vs. 29%, p < 0.001). The same was true when grading was based on 55° ICGA. CONCLUSIONS: The CVH patterns of uni-FISH, multi-FISH, and DISH are typical of CSC. These patterns correlate with established signs of CSC chronicity. Their predictive role in treatment response and prognosis remains to be evaluated.

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.

The Analysis of Embryoid Body Formation and Its Role in Retinal Organoid Development.

Within the last decade, a wide variety of protocols have emerged for the generation of retinal organoids. A subset of studies have compared protocols based on stem cell source, the physical features of the microenvironment, and both internal and external signals, all features that influence embryoid body and retinal organoid formation. Most of these comparisons have focused on the effect of signaling pathways on retinal organoid development. In this study, our aim is to understand whether starting cell conditions, specifically those involved in embryoid body formation, affect the development of retinal organoids in terms of differentiation capacity and reproducibility. To investigate this, we used the popular 3D floating culture method to generate retinal organoids from stem cells. This method starts with either small clumps of stem cells generated from larger clones (clumps protocol, CP) or with an aggregation of single cells (single cells protocol, SCP). Using histological analysis and gene-expression comparison, we found a retention of the pluripotency capacity on embryoid bodies generated through the SCP compared to the CP. Nonetheless, these early developmental differences seem not to impact the final retinal organoid formation, suggesting a potential compensatory mechanism during the neurosphere stage. This study not only facilitates an in-depth exploration of embryoid body development but also provides valuable insights for the selection of the most suitable protocol in order to study retinal development and to model inherited retinal disorders in vitro.

The Road towards Gene Therapy for X-Linked Juvenile Retinoschisis: A Systematic Review of Preclinical Gene Therapy in Cell-Based and Rodent Models of XLRS.

X-linked juvenile retinoschisis (XLRS) is an early-onset progressive inherited retinopathy affecting males. It is characterized by abnormalities in the macula, with formation of cystoid retinal cavities, frequently accompanied by splitting of the retinal layers, impaired synaptic transmission of visual signals, and associated loss of visual acuity. XLRS is caused by loss-of-function mutations in the retinoschisin gene located on the X chromosome (RS1, MIM 30083). While proof-of-concept studies for gene augmentation therapy have been promising in in vitro and rodent models, clinical trials in XLRS patients have not been successful thus far. We performed a systematic literature investigation using search strings related to XLRS and gene therapy in in vivo and in vitro models. Three rounds of screening (title/abstract, full text and qualitative) were performed by two independent reviewers until consensus was reached. Characteristics related to study design and intervention were extracted from all studies. Results were divided into studies using (1) viral and (2) non-viral therapies. All in vivo rodent studies that used viral vectors were assessed for quality and risk of bias using the SYRCLE's risk-of-bias tool. Studies using alternative and non-viral delivery techniques, either in vivo or in vitro, were extracted and reviewed qualitatively, given the diverse and dispersed nature of the information. For in-depth analysis of in vivo studies using viral vectors, outcome data for optical coherence tomography (OCT), immunohistopathology and electroretinography (ERG) were extracted. Meta-analyses were performed on the effect of recombinant adeno-associated viral vector (AAV)-mediated gene augmentation therapies on a- and b-wave amplitude as well as the ratio between b- and a-wave amplitudes (b/a-ratio) extracted from ERG data. Subgroup analyses and meta-regression were performed for model, dose, age at injection, follow-up time point and delivery method. Between-study heterogeneity was assessed with a Chi-square test of homogeneity (I2). We identified 25 studies that target RS1 and met our search string. A total of 19 of these studies reported rodent viral methods in vivo. Six of the 25 studies used non-viral or alternative delivery methods, either in vitro or in vivo. Of these, five studies described non-viral methods and one study described an alternative delivery method. The 19 aforementioned in vivo studies were assessed for risk of bias and quality assessments and showed inconsistency in reporting. This resulted in an unclear risk of bias in most included studies. All 19 studies used AAVs to deliver intact human or murine RS1 in rodent models for XLRS. Meta-analyses of a-wave amplitude, b-wave amplitude, and b/a-ratio showed that, overall, AAV-mediated gene augmentation therapy significantly ameliorated the disease phenotype on these parameters. Subgroup analyses and meta-regression showed significant correlations between b-wave amplitude effect size and dose, although between-study heterogeneity was high. This systematic review reiterates the high potential for gene therapy in XLRS, while highlighting the importance of careful preclinical study design and reporting. The establishment of a systematic approach in these studies is essential to effectively translate this knowledge into novel and improved treatment alternatives.

Choroidal Vascular Changes on Ultrawidefield Indocyanine Green Angiography in Central Serous Chorioretinopathy: CERTAIN Study Report 1.

PURPOSE: Choroidal venous overload was recently suggested to be a pathogenetic factor in central serous chorioretinopathy (CSC). Manifestations of venous overload on ultrawidefield indocyanine green angiography (UWF ICGA) include asymmetric arterial choroidal filling (AACF), enlarged choroidal vessels ("pachyvessels"), and asymmetric venous drainage (AVD) leading to choroidal intervortex venous anastomoses (CVAs) accompanied by choroidal vascular hyperpermeability (CVH). The purpose of the current study is to assess the presence of these signs of venous overload in a large cohort of CSC patients. DESIGN: Monocentric retrospective cohort study. PARTICIPANTS: Consecutive CSC patients seen at a large tertiary referral center. METHODS: For the CERTAIN study, patients underwent a standardized imaging protocol including UWF ICGA. Features of choroidal venous overload were graded for each eye individually by 2 independent graders and, in case of disagreement, by a third grader. MAIN OUTCOME MEASURES: Presence of AAFC, pachyvessels, AVD, CVA, and CVH. RESULTS: In total, 178 eyes of 91 patients were included in this study. Mean patient age was 47.6 (± 12.0) years and 75 patients (82%) were male. The 116 eyes (65%) that showed subretinal fluid were considered affected (bilateral disease in 29 patients). In affected eyes, AACF was present in 62 eyes (85% of gradable eyes), pachyvessels in 102 eyes (88%), AVD in 81 eyes (74%), CVA in 107 eyes (94%), and CVH in 100% of affected eyes. For fellow eyes, prevalence of pachyvessels (94%), AVD (67%), and CVA (90%) was similar to affected eyes, whereas CVH was present in 85% of fellow eyes. Intergrader agreement was excellent for CVH (94%), and 74%-82% for all other criteria. Patients with pachyvessels and AVD in 1 eye were more likely to also show the same characteristic in the fellow eye (odds ratios 22.2 and 9.9, P < 0.01). CONCLUSIONS: Signs of venous overload are seen in the vast majority of CSC patients, both in affected and unaffected eyes. Although pachyvessels, AVD, and CVA are observed frequently, CVH was observed in all affected eyes, showed excellent intergrader reliability, and is diagnostic for CSC. This supports the concept of choroidal venous overload as a major factor in CSC pathogenesis. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

CORRELATION BETWEEN MICROPERIMETRY AND IMAGING IN EXTENSIVE MACULAR ATROPHY WITH PSEUDODRUSEN-LIKE APPEARANCE.

PURPOSE: To determine the correlation between microperimetry and imaging findings in extensive macular atrophy with pseudodrusen-like appearance (EMAP). METHODS: This cross-sectional, observational study included 44 consecutive patients with EMAP (88 eyes) and 30 healthy subjects (60 eyes). Both groups underwent visual acuity assessment, mesopic and scotopic microperimetry, fundus photography, autofluorescence, optical coherence tomography, and optical coherence tomography angiography. Retinal sensitivity was also subdivided in macular (0-4°) and paramacular areas (8-10°). Scotopic sensitivity loss was defined as the difference between scotopic and mesopic sensitivities for each tested point. Eyes with EMAP were further classified into the three stages described by Romano et al: 19 eyes in Stage 1, 31 in Stage 2, and 38 in Stage 3. RESULTS: Mesopic and scotopic retinal sensitivity were significantly reduced in patients with EMAP compared with controls, particularly in the macular area (all P < 0.001). Mesopic retinal sensitivity progressively declined in more advanced EMAP stages (all P < 0.01), but no scotopic differences were observed between Stages 2 and 3 ( P = 0.08). Remarkably, scotopic sensitivity loss was significantly higher in Stage 1 ( P < 0.05).On multivariate analysis, mesopic dysfunction was associated with larger atrophic areas ( P < 0.01), foveal involvement ( P = 0.03), and fibrosis ( P = 0.02). Conversely, no independent variable was associated with a reduced scotopic retinal sensitivity (all P > 0.05). CONCLUSION: The findings highlight that patients with EMAP suffer from a severe cone- and rod-mediated dysfunction on microperimetry. The predominant rod impairment in the early cases (Stage 1) emphasizes the importance of dark-adapted scotopic microperimetry as a clinical end point and suggests defective transportation across the RPE-Bruch membrane complex in its pathogenesis.

BASELINE SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHIC RETINAL LAYER FEATURES IDENTIFIED BY ARTIFICIAL INTELLIGENCE PREDICT THE COURSE OF CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To identify optical coherence tomography (OCT) features to predict the course of central serous chorioretinopathy (CSC) with an artificial intelligence-based program. METHODS: Multicenter, observational study with a retrospective design. Treatment-naïve patients with acute CSC and chronic CSC were enrolled. Baseline OCTs were examined by an artificial intelligence-developed platform (Discovery OCT Fluid and Biomarker Detector, RetinAI AG, Switzerland). Through this platform, automated retinal layer thicknesses and volumes, including intaretinal and subretinal fluid, and pigment epithelium detachment were measured. Baseline OCT features were compared between acute CSC and chronic CSC patients. RESULTS: One hundred and sixty eyes of 144 patients with CSC were enrolled, of which 100 had chronic CSC and 60 acute CSC. Retinal layer analysis of baseline OCT scans showed that the inner nuclear layer, the outer nuclear layer, and the photoreceptor-retinal pigmented epithelium complex were significantly thicker at baseline in eyes with acute CSC in comparison with those with chronic CSC ( P < 0.001). Similarly, choriocapillaris and choroidal stroma and retinal thickness (RT) were thicker in acute CSC than chronic CSC eyes ( P = 0.001). Volume analysis revealed average greater subretinal fluid volumes in the acute CSC group in comparison with chronic CSC ( P = 0.041). CONCLUSION: Optical coherence tomography features may be helpful to predict the clinical course of CSC. The baseline presence of an increased thickness in the outer retinal layers, choriocapillaris and choroidal stroma, and subretinal fluid volume seems to be associated with acute course of the disease.

MULTIMODAL RETINAL IMAGING REVEALS NEW PATHOGENIC INSIGHTS IN CENTRAL AREOLAR CHOROIDAL DYSTROPHY: A CASE SERIES.

PURPOSE: To describe novel imaging findings in a family affected by central areolar choroidal dystrophy. METHODS: Case series with multimodal retinal imaging assessment. RESULTS: A 19-year-old asymptomatic woman was referred for bilateral macular defects of the retinal pigment epithelium. Blue-light autofluorescence of her right eye revealed a speckled pattern in the macular area with a ring of decreased autofluorescence using near-infrared autofluorescence. Multimodal assessment of her left eye disclosed a single parafoveal spot of decreased pigmentation that was clearly visible as hyperautofluorescent using blue-light autofluorescence and as hypoautofluorescent using near-infrared autofluorescence. Optical coherence tomography angiography revealed several tiny areas of flow voids in correspondence of the retinal pigment epithelium alterations of both eyes. Three family members were recently diagnosed with presumed age-related macular degeneration and demonstrated well-demarcated areas of retinal pigment epithelium atrophy surrounded by yellowish deposits and a hypopigmented halo. Next-generation genetic analysis for inherited macular dystrophies was performed on the index case and the affected family members and revealed a p.Arg172Gln missense mutation in PRPH2 gene, leading to the diagnosis of central areolar choroidal dystrophy. CONCLUSION: Multimodal imaging can reveal new pathogenic insights in central areolar choroidal dystrophy. Of notice, near-infrared autofluorescence and optical coherence tomography angiography are able to detect retinal pigment epithelium hypopigmentation and choriocapillaris rarefaction, respectively, since the earliest stages of the disease.

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.

Clinical, Genotypic, and Imaging Characterization of the Spectrum of ABCA4 Retinopathies.

PURPOSE: To investigate the clinical and genotypic differences in the spectrum of ABCA4-associated retinopathies (ABCA4Rs). DESIGN: Observational, cross sectional case series. PARTICIPANTS: Sixty-six patients (132 eyes) carrying biallelic ABCA4 variants. METHODS: Patients underwent visual acuity measurement and multimodal imaging. Clinical records were reviewed for age at onset, presenting symptoms, genetic variants, and electroretinogram (ERG). Each eye was assigned to a phenotype based on age at onset, imaging and ERG: cone dystrophy-bull's-eye maculopathy (CD-BEM, 40 eyes), cone-rod dystrophy (CRD, 12 eyes), Stargardt disease (SD, 28 eyes), late-onset SD (LO-SD, 38 eyes), and fundus flavimaculatus (14 eyes). Images were analyzed for: peripapillary sparing, retinal pigment epithelium (RPE) atrophy (definitely decreased autofluorescence, DDAF), flecks patterns using autofluorescence; type of atrophy according to Classification of Atrophy Meeting reports, macular and choroidal thickness on OCT; and choriocapillaris flow deficits on OCT angiography. MAIN OUTCOME MEASURES: Primary outcome was to report the demographic, genotypic, and imaging characteristics of the different ABCA4R phenotypes. Secondary objectives included the assessment of imaging biomarkers as outcome measures for clinical trials. RESULTS: Age at onset was lower in CRD (12 ± 8 years) and higher in patients with LO-SD (59 ± 9 years) (all P < 0.01). Central vision loss was a common presenting symptom in CD-BEM and SD, whereas patients with LO-SD primarily complained of difficult dark adaptation. Missense variants were more frequent in CD-BEM, and splice site in CRD and LO-SD (P < 0.05). Peripapillary sparing was absent in 3 eyes with LO-SD (8%). Cone dystrophy-bull's-eye maculopathy eyes typically had complete outer retinal atrophy alterations (98%), whereas CRD and SD eyes showed both complete outer retinal atrophy and complete RPE and outer retinal atrophy (cRORA) (71%-100%). Patients with LO-SD had larger areas of DDAF (100% cRORA) and of choriocapillaris flow deficits (all P < 0.01). Repeatability of DDAF measurements was low for some phenotypes (CD-BEM and CRD) and atrophic areas <7.5 mm2. Resorbed flecks were significantly associated with CRD and LO-SD (P < 0.01). CONCLUSIONS: This research provides a thorough evaluation of the spectrum of ABCA4R. Our findings suggest that certain phenotypes show preferential photoreceptor degeneration (e.g., CD-BEM), whereas others have substantial RPE and choriocapillaris alterations (e.g., LO-SD). We recommend that clinical trial end points take into consideration these imaging features to improve the interpretation of their results. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

NOn-Pachychoroid PEripapillary Schisis (NOPPES) of the Retina: A New Phenotype and its Differential Diagnosis.

PURPOSE: The presence of peripapillary intraretinal fluid (IRF) has a broad differential diagnosis, including several types of neovascular and pachychoroid-related diseases. However, the clinician may encounter cases without signs of neovascular or pachychoroid disease, or any other previously described diagnosis. For these patients, we propose the term NOn-Pachychoroid PEripapillary Schisis (NOPPES) of the retina, and we discuss the differential diagnosis. DESIGN: A retrospective chart study set in a tertiary referral center for retinal diseases in Amsterdam, the Netherlands. METHODS: Using multimodal imaging, cases suspected of peripapillary pachychoroid syndrome were reviewed. Cases without signs of neovascular or pachychoroid disease were included in this study. These cases were discussed in a group of senior retinal specialists to establish a diagnosis, and if there was no evidence for any previously described diagnostic entity, these cases were categorized as NOPPES. RESULTS: Four cases of NOPPES were identified, 3 female patients and 1 male patient, aged between 58 and 75 years. Two patients were myopic, and 1 patient had a mild hyperopia. Three out of 4 cases showed unilateral peripapillary IRF, and 1 case had bilateral IRF. No improvement was seen after intravitreal bevacizumab or aflibercept, nepafenac eye drops, oral acetazolamide, vitrectomy with internal limiting membrane peeling, or surgery for carotid stenosis. One case showed a reduction in IRF after starting prednisolone eye drops. CONCLUSIONS: We describe NOPPES, a new form of peripapillary schisis-like IRF. NOPPES seems relatively therapy-resistant. More research is needed to delineate the clinical spectrum of NOPPES and its pathogenesis and treatment.

CRB1-Associated Retinal Dystrophy Patients Have Expanded Lewis Glycoantigen-Positive T Cells.

Purpose: Eye inflammation may occur in patients with inherited retinal dystrophies (IRDs) and is seen frequently in IRDs associated with mutations in the CRB1 gene. The purpose of this study was to determine the types of inflammatory cells involved in IRDs, by deep profiling the composition of peripheral blood mononuclear cells of patients with a CRB1-associated IRD. Methods: This study included 33 patients with an IRD with confirmed CRB1 mutations and 32 healthy controls. A 43-parameter flow cytometry analysis was performed on peripheral blood mononuclear cells isolated from venous blood. FlowSOM and manual Boolean combination gating were used to identify and quantify immune cell subsets. Results: Comparing patients with controls revealed a significant increase in patients in the abundance of circulating CD4+ T cells and CD8+ T cells that express sialyl Lewis X antigen. Furthermore, we detected a decrease in plasmacytoid dendritic cells and an IgA+CD24+CD38+ transitional B-cell subset in patients with an IRD. Conclusions: Patients with a CRB1-associated IRD show marked changes in blood leukocyte composition, affecting lymphocyte and dendritic cell populations. These results implicate inflammatory pathways in the disease manifestations of IRDs.

Characterization and AAV-mediated CRB gene augmentation in human-derived CRB1KO and CRB1KOCRB2+/- retinal organoids.

The majority of patients with mutations in CRB1 develop either early-onset retinitis pigmentosa as young children or Leber congenital amaurosis as newborns. The cause for the phenotypic variability in CRB1-associated retinopathies is unknown, but might be linked to differences in CRB1 and CRB2 protein levels in Müller glial cells and photoreceptor cells. Here, CRB1KO and CRB1KOCRB2+/- differentiation day 210 retinal organoids showed a significant decrease in the number of photoreceptor nuclei in a row and a significant increase in the number of photoreceptor cell nuclei above the outer limiting membrane. This phenotype with outer retinal abnormalities is similar to CRB1 patient-derived retinal organoids and Crb1 or Crb2 mutant mouse retinal disease models. The CRB1KO and CRB1KOCRB2+/- retinal organoids develop an additional inner retinal phenotype due to the complete loss of CRB1 from Müller glial cells, suggesting an essential role for CRB1 in proper localization of neuronal cell types. Adeno-associated viral (AAV) transduction was explored at early and late stages of organoid development. Moreover, AAV-mediated gene augmentation therapy with AAV.hCRB2 improved the outer retinal phenotype in CRB1KO retinal organoids. Altogether, these data provide essential information for future gene therapy approaches for patients with CRB1-associated retinal dystrophies.

KCNV2-associated retinopathy: genotype-phenotype correlations - KCNV2 study group report 3.

BACKGROUND/AIMS: To investigate genotype-phenotype associations in patients with KCNV2 retinopathy. METHODS: Review of clinical notes, best-corrected visual acuity (BCVA), molecular variants, electroretinography (ERG) and retinal imaging. Subjects were grouped according to the combination of KCNV2 variants-two loss-of-function (TLOF), two missense (TM) or one of each (MLOF)-and parameters were compared. RESULTS: Ninety-two patients were included. The mean age of onset (mean±SD) in TLOF (n=55), TM (n=23) and MLOF (n=14) groups was 3.51±0.58, 4.07±2.76 and 5.54±3.38 years, respectively. The mean LogMAR BCVA (±SD) at baseline in TLOF, TM and MLOF groups was 0.89±0.25, 0.67±0.38 and 0.81±0.35 for right, and 0.88±0.26, 0.69±0.33 and 0.78±0.33 for left eyes, respectively. The difference in BCVA between groups at baseline was significant in right (p=0.03) and left eyes (p=0.035). Mean outer nuclear layer thickness (±SD) at baseline in TLOF, MLOF and TM groups was 37.07±15.20 µm, 40.67±12.53 and 40.38±18.67, respectively, which was not significantly different (p=0.85). The mean ellipsoid zone width (EZW) loss (±SD) was 2051 µm (±1318) for patients in the TLOF, and 1314 µm (±965) for MLOF. Only one patient in the TM group had EZW loss at presentation. There was considerable overlap in ERG findings, although the largest DA 10 ERG b-waves were associated with TLOF and the smallest with TM variants. CONCLUSIONS: Patients with missense alterations had better BCVA and greater structural integrity. This is important for patient prognostication and counselling, as well as stratification for future gene therapy trials.

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.

CRB1 is required for recycling by RAB11A+ vesicles in human retinal organoids.

CRB1 gene mutations can cause early- or late-onset retinitis pigmentosa, Leber congenital amaurosis, or maculopathy. Recapitulating human CRB1 phenotypes in animal models has proven challenging, necessitating the development of alternatives. We generated human induced pluripotent stem cell (iPSC)-derived retinal organoids of patients with retinitis pigmentosa caused by biallelic CRB1 mutations and evaluated them against autologous gene-corrected hiPSCs and hiPSCs from healthy individuals. Patient organoids show decreased levels of CRB1 and NOTCH1 expression at the retinal outer limiting membrane. Proximity ligation assays show that human CRB1 and NOTCH1 can interact via their extracellular domains. CRB1 patient organoids feature increased levels of WDFY1+ vesicles, fewer RAB11A+ recycling endosomes, decreased VPS35 retromer complex components, and more degradative endolysosomal compartments relative to isogenic control organoids. Taken together, our data demonstrate that patient-derived retinal organoids enable modeling of retinal degeneration and highlight the importance of CRB1 in early endosome maturation receptor recycling in the retina.

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.