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Purpose: To report a case of macular hole and detachment occurring after the subretinal injection of Voretigene Neparvovec (VN) in a patient affected by atypical RPE65 retinal dystrophy with high myopia and its successful surgical management. Case description: We report a case of a 70-year-old man treated with VN in both eyes. The best corrected visual acuity (BCVA) was 0.7 LogMar in the right eye (RE) and 0.92 LogMar in the left eye (LE). Axial length was 29.60 mm in the RE and 30.28 mm in the LE. Both eyes were pseudophakic. In both eyes, fundus examination revealed high myopia, posterior staphyloma, and extended retinal atrophy areas at the posterior pole, circumscribing a central island of surviving retina. Both eyes were treated with VN subretinal injection, but a full-thickness macular hole and retinal detachment occurred in the LE three weeks after surgery. The patient underwent 23-gauge vitrectomy with internal limiting membrane (ILM) peeling and the inverted flap technique with sulfur hexafluoride (SF6) 20% tamponade. Postoperative follow-up showed that the macular hole was closed and the BCVA was maintained. Conclusions: Our experience suggests that patients with atypical RPE65 retinal dystrophy and high myopia undergoing VN subretinal injection require careful management to minimize the risk of macular hole and detachment occurrence and promptly detect and address these potential complications. [ABSTRACT FROM AUTHOR]

Background Recent studies suggest that 5α-reductase inhibitors (5ARIs) for benign prostate hyperplasia (BPH) result in abnormal retinal anatomical alteration. Objective To compare age-related macular degeneration (AMD) incidence in BPH patients receiving 5ARIs or tamsulosin. Design Retrospective, population-based cohort study using new-user and active-comparator design. Setting General population. Subjects Males with BPH, newly receiving 5ARIs or tamsulosin from 2010 to 2018. Methods Data were extracted from Taiwan's National Health Insurance Research Database. We used Cox proportional hazards model with 1:4 propensity score (PS) matching, based on intention-to-treat analysis to determine the risk of incident AMD. Sensitivity analyses included an as-treated approach and weighting-based PS methods. We also separately reported the risks of incident AMD in patients receiving finasteride and dutasteride to determine risk differences among different 5ARIs. Results We included 13 586 5ARIs users (mean age: 69 years) and 54 344 tamsulosin users (mean age: 68.37 years). After a mean follow-up of 3.7 years, no differences were observed in the risk of incident AMD between 5ARIs and tamsulosin users [hazard ratio (HR): 1.06; 95% confidence intervals (95% CI): 0.98–1.15], with similar results from sensitivity analyses. However, increased risk of incident age-related macular degeneration was observed in patients receiving dutasteride [HR: 1.13; 95% CI: 1.02–1.25], but not in those receiving finasteride [HR: 0.99; 95% CI: 0.87–1.12], in the subgroup analyses. Conclusions We found no difference between 5ARIs and tamsulosin regarding the incidence of AMD in BPH patients. However, the risk profiles for AMD differed slightly between dutasteride and finasteride, suggesting that the potency of androgen inhibition is a factor related to AMD incidence. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders. [ABSTRACT FROM AUTHOR]

Copyright of Folia Pharmacologica Japonica is the property of Japanese Pharmacological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jalili syndrome (JS) (MIM#217080) is a rare autosomal recessive disorder with oculo‐dental malformations. The clinical phenotype is characterized by the presence of Cone‐Rod Dystrophy (CRD) and Amelogenesis Imperfecta (AI). Genetic mechanism entails a mutation in the CNNM4, a metal transporter gene located on Chromosome 2q11.2. A high fluoride concentration in groundwater has also been identified as an epigenetic factor in this syndrome. JS draws the attention of dentists due to its distinct oral manifestations. To the best of our knowledge, this is the first genetically confirmed pediatric case report from the Indian subcontinent emphasizing the clinical and radiographic features of this condition and its management in a 6‐year‐old child. [ABSTRACT FROM AUTHOR]

Retinitis pigmentosa (RP) is the most common inherited retinal dystrophy and a major cause of blindness. RP is caused by several variants of multiple genes, and genetic diagnosis by identifying these variants is important for optimizing treatment and estimating patient prognosis. Next-generation sequencing (NGS), which is currently widely used for diagnosis, is considered useful but is known to have limitations in detecting copy number variations (CNVs). In this study, we re-evaluated CNVs in EYS, the main causative gene of RP, identified via NGS using multiplex ligation-dependent probe amplification (MLPA). CNVs were identified in NGS samples of eight patients. To identify potential CNVs, MLPA was also performed on samples from 42 patients who were undiagnosed by NGS but carried one of the five major pathogenic variants reported in Japanese EYS-RP cases. All suspected CNVs based on NGS data in the eight patients were confirmed via MLPA. CNVs were found in 2 of the 42 NGS-undiagnosed RP cases. Furthermore, results showed that 121 of the 661 patients with RP had EYS as the causative gene, and 8.3% (10/121 patients with EYS-RP) had CNVs. Although NGS using the CNV calling criteria utilized in this study failed to identify CNVs in two cases, no false-positive results were detected. Collectively, these findings suggest that NGS is useful for CNV detection during clinical diagnosis of RP. [ABSTRACT FROM AUTHOR]

Retinal optical coherence tomography has been identified as biomarker for disease progression in relapsing-remitting multiple sclerosis (RRMS), while the dynamics of retinal atrophy in progressive MS are less clear. We investigated retinal layer thickness changes in RRMS, primary and secondary progressive MS (PPMS, SPMS), and their prognostic value for disease activity. Here, we analyzed 2651 OCT measurements of 195 RRMS, 87 SPMS, 125 PPMS patients, and 98 controls from five German MS centers after quality control. Peripapillary and macular retinal nerve fiber layer (pRNFL, mRNFL) thickness predicted future relapses in all MS and RRMS patients while mRNFL and ganglion cell-inner plexiform layer (GCIPL) thickness predicted future MRI activity in RRMS (mRNFL, GCIPL) and PPMS (GCIPL). mRNFL thickness predicted future disability progression in PPMS. However, thickness change rates were subject to considerable amounts of measurement variability. In conclusion, retinal degeneration, most pronounced of pRNFL and GCIPL, occurs in all subtypes. Using the current state of technology, longitudinal assessments of retinal thickness may not be suitable on a single patient level. The prognostic value of OCT in progressive vs relapsing multiple sclerosis (MS) is not clear. Analyzing 2651 OCTs of 407 MS patients, OCT predicted activity in all MS subtypes cross sectionally but longitudinal changes were not predictive in a multicenter setting. [ABSTRACT FROM AUTHOR]

Background: Biallelic pathogenic variants in USH2A lead to Usher syndrome or non-syndromic retinitis pigmentosa, and shown to have geographical and ethnical distribution in previous studies. This study provided a deeper understanding of the detailed clinical features using multimodal imaging, genetic spectrum, and genotype–phenotype correlations of USH2A-related retinal dystrophies in Taiwan. Results: In our cohort, the mean age at first visit was 47.66 ± 13.54 years, and the mean age at symptom onset, which was referred to the onset of nyctalopia and/or visual field constriction, was 31.21 ± 15.24 years. Among the variants identified, 23 (50%) were missense, 10 (22%) were splicing variants, 8 (17%) were nonsense, and 5 (11%) were frameshift mutations. The most predominant variant was c.2802T>G, which accounted for 21% of patients, and was located in exon 13. Patients with truncated alleles had significantly earlier symptom onset and seemly poorer disease progression regarding visual acuity, ellipsoid zone line length, and hypofluorescent lesions in the macula than those who had the complete gene. However, the clinical presentation revealed similar progression between patients with and without the c.2802T>G variant. During long-term follow-up, the patients had different ellipsoid zone line progression rates and were almost evenly distributed in the fast, moderate, and slow progression subgroups. Although a younger onset age and a smaller baseline intact macular area was observed in the fast progression subgroup, the results showed no significant difference. Conclusions: This is the first cohort study to provide detailed genetic and longitudinal clinical analyses of patients with USH2A-related retinal dystrophies in Taiwan. The mutated allele frequency in exon 13 was high in Taiwan due to the predominant c.2802T>G variant. Moreover, truncated variants greatly impacted disease progression and determined the length of therapeutic windows. These findings provide insight into the characteristics of candidates for future gene therapies. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the local status of the sclera in lattice retinal degeneration. Patients with lattice degeneration, snail-track degeneration, or horseshoe retinal breaks were included. One lesion of a single eye in each patient was captured with cross-sectional optical coherence tomography (OCT) along and across the greatest lesion dimension. The maximum height of scleral indentation was measured and compared between different lesion types and between lattice lesions with and without retinal breakage or local detachment. The correlation between the maximum height of the scleral indentation of lattice lesions and the age of the patients was calculated. Seventy-five eyes of 75 patients (44.4 ± 14.7 years; 35 males and 30 females) were included. OCT showed variable local scleral indentation in 52 out of 55 (94.5%) lattice lesions, in five out of nine (55.5%) snail-tack lesions, and in three out of eleven (27.3%) horseshoe breaks. The maximum scleral indentation within lattice lesions, snail-tack lesions, and horseshoe breaks was 227.2 ± 111.3, 22.0 ± 49.2, and 88.5 ± 48.4 µm, respectively (p < 0.001 for snail-tack lesions and horseshoe breaks compared to lattice lesions). Lattice lesions with retinal breaks and/or local retinal detachment had statistically significantly lower scleral indentation than those without (p = 0.01). The height of the scleral indentation of lattice lesions was positively correlated with patient age (r = 0.51, p = 0.03). In conclusion, scleral indentation is one of the hallmarks of lattice retinal degeneration and may be associated with a reduced risk of rhegmatogenous retinal detachment. [ABSTRACT FROM AUTHOR]

Choroideremia is an X-linked chorioretinal dystrophy caused by mutations in CHM, encoding Rab escort protein 1 (REP-1), leading to under-prenylation of Rab GTPases (Rabs). Despite ubiquitous expression of CHM, the phenotype is limited to degeneration of the retina, retinal pigment epithelium (RPE), and choroid, with evidence for primary pathology in RPE cells. However, the spectrum of under-prenylated Rabs in RPE cells and how they contribute to RPE dysfunction remain unknown. A CRISPR/Cas-9-edited CHM−/− iPSC-RPE model was generated with isogenic control cells. Unprenylated Rabs were biotinylated in vitro and identified by tandem mass tag (TMT) spectrometry. Rab12 was one of the least prenylated and has an established role in suppressing mTORC1 signaling and promoting autophagy. CHM−/− iPSC-RPE cells demonstrated increased mTORC1 signaling and reduced autophagic flux, consistent with Rab12 dysfunction. Autophagic flux was rescued in CHM−/− cells by transduction with gene replacement (ShH10-CMV-CHM) and was reduced in control cells by siRNA knockdown of Rab12. This study supports Rab12 under-prenylation as an important cause of RPE cell dysfunction in choroideremia and highlights increased mTORC1 and reduced autophagy as potential disease pathways for further investigation. [ABSTRACT FROM AUTHOR]

Inherited retinal dystrophies comprise a clinically complex and heterogenous group of diseases characterized by visual impairment due to pathogenic variants of over 300 different genes. Accurately identifying the causative gene and associated variant is crucial for the definitive diagnosis and subsequent selection of precise treatments. Consequently, well-validated genetic tests are required in the clinical practice. Here, we report the analytical and clinical validation of a next-generation sequencing targeted gene panel, the PrismGuide IRD Panel System. This system enables comprehensive genome profiling of 82 genes related to inherited retinal dystrophies. The PrismGuide IRD Panel System demonstrated 100% (n = 43) concordance with Sanger sequencing in detecting single-nucleotide variants, small insertions, and small deletions in the target genes and also in assessing their zygosity. It also identified copy-number loss in four out of five cases. When assessing precision, we evaluated the reproducibility of variant detection with 2,160 variants in 144 replicates and found 100% agreement in terms of single-nucleotide variants (n = 1,584) and small insertions and deletions (n = 576). Furthermore, the PrismGuide IRD Panel System generated sufficient read depth for variant calls across the purine-rich and highly repetitive open-reading frame 15 region of RPGR and detected all five variants tested. These results show that the PrismGuide IRD Panel System can accurately and consistently detect single-nucleotide variants and small insertions and deletions. Thus, the PrismGuide IRD Panel System could serve as useful tool that is applicable in clinical practice for identifying the causative genes based on the detection and interpretation of variants in patients with inherited retinal dystrophies and can contribute to a precise molecular diagnosis and targeted treatments. [ABSTRACT FROM AUTHOR]

Purpose: Observational studies have reported inconsistent results on the relationship between chronic kidney disease (CKD) and age-related macular degeneration (AMD). The primary objective of this study was to investigate the causal relationships between estimated glomerular filtration rate (eGFR), CKD, its common causes, and AMD among participants of European descent. Methods: Genetic variants associated with eGFR, CKD and its common causes, encompassing diabetic nephropathy (DN), immunoglobulin A nephropathy (IgAN), and membranous nephropathy (MN) were obtained from previously published genome-wide association studies (GWAS) and FinnGen database. Summary statistics for early AMD, AMD, dry AMD, and wet AMD were acquired from the GWAS and FinnGen database. Inverse-variance-weighted (IVW) method was the main MR analysis. Sensitivity analyses were performed with Cochran's Q, MR-Egger intercept, and leave-one-out analysis. In addition, RadialMR was utilized to identify and remove outliers. Results: IVW results showed that CKD, eGFR were not associated with any type of AMD (p > 0.05). DN (OR: 1.042, 95% CI: 1.002-1.083, p = 0.037) and MN (OR: 1.023, 95% CI: 1.007-1.040, p = 0.005) were associated with an increased risk of earl AMD. DN (OR: 1.111, 95% CI: 1.07-1.154, p = 4.87 × 10-8), IgAN (OR: 1.373, 95% CI: 1.097-1.719, p = 0.006), and MN (OR: 1.036, 95% CI: 1.008-1.064, p = 0.012) were associated with an increased risk of AMD. DN (OR: 1.090, 95% CI: 1.042-1.140, p = 1.57 × 10-4) and IgAN (OR: 1.480, 95% CI: 1.178-1.858, p = 7.55 × 10-4) were associated with an increased risk of dry AMD. The risk of wet AMD was associated with DN (OR: 1.107, 95% CI: 1.043-1.174, p = 7.56 × 10-4) and MN (OR: 1.071, 95% CI: 1.040-1.103, p = 5.48 × 10-6). Conclusion: This MR study found no evidence of causal relationship between CKD and AMD. DN, IgAN, and MN may increase risk of AMD. This findings underscore the importance of ocular examinations in patients with DN, MN, and IgAN. More studies are needed to support the findings of our current study. [ABSTRACT FROM AUTHOR]

BACKGROUND: CEP290-associated inherited retinal degeneration causes severe early-onset vision loss due to pathogenic variants in CEP290. EDIT-101 is a clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) gene-editing complex designed to treat inherited retinal degeneration caused by a specific damaging variant in intron 26 of CEP290 (IVS26 variant). METHODS: We performed a phase 1-2, open-label, single-ascending-dose study in which persons 3 years of age or older with CEP290-associated inherited retinal degeneration caused by a homozygous or compound heterozygous IVS26 variant received a subretinal injection of EDIT-101 in the worse (study) eye. The primary outcome was safety, which included adverse events and dose-limiting toxic effects. Key secondary efficacy outcomes were the change from baseline in the best corrected visual acuity, the retinal sensitivity detected with the use of full-field stimulus testing (FST), the score on the Ora-Visual Navigation Challenge mobility test, and the vision-related quality-of-life score on the National Eye Institute Visual Function Questionnaire-25 (in adults) or the Children's Visual Function Questionnaire (in children). RESULTS: EDIT-101 was injected in 12 adults 17 to 63 years of age (median, 37 years) at a low dose (in 2 participants), an intermediate dose (in 5), or a high dose (in 5) and in 2 children 9 and 14 years of age at the intermediate dose. At baseline, the median best corrected visual acuity in the study eye was 2.4 log10 of the minimum angle of resolution (range, 3.9 to 0.6). No serious adverse events related to the treatment or procedure and no dose-limiting toxic effects were recorded. Six participants had a meaningful improvement from baseline in cone-mediated vision as assessed with the use of FST, of whom 5 had improvement in at least one other key secondary outcome. Nine participants (64%) had a meaningful improvement from baseline in the best corrected visual acuity, the sensitivity to red light as measured with FST, or the score on the mobility test. Six participants had a meaningful improvement from baseline in the vision-related quality-of-life score. CONCLUSIONS: The safety profile and improvements in photoreceptor function after EDIT-101 treatment in this small phase 1-2 study support further research of in vivo CRISPR-Cas9 gene editing to treat inherited retinal degenerations due to the IVS26 variant of CEP290 and other genetic causes. (Funded by Editas Medicine and others; BRILLIANCE ClinicalTrials.gov number, NCT03872479.). [ABSTRACT FROM AUTHOR]

The functionality of photoreceptors, rods, and cones is highly dependent on their outer segments (POS), a cellular compartment containing highly organized membranous structures that generate biochemical signals from incident light. While POS formation and degeneration are qualitatively assessed on microscopy images, reliable methodology for quantitative analyses is still limited. Here, we developed methods to quantify POS (QuaPOS) maturation and quality on retinal sections using automated image analyses. POS formation was examined during the development and in adulthood of wild-type mice via light microscopy (LM) and transmission electron microscopy (TEM). To quantify the number, size, shape, and fluorescence intensity of POS, retinal cryosections were immunostained for the cone POS marker S-opsin. Fluorescence images were used to train the robust classifier QuaPOS-LM based on supervised machine learning for automated image segmentation. Characteristic features of segmentation results were extracted to quantify the maturation of cone POS. Subsequently, this quantification method was applied to characterize POS degeneration in "cone photoreceptor function loss 1" mice. TEM images were used to establish the ultrastructural quantification method QuaPOS-TEM for the alignment of POS membranes. Images were analyzed using a customwritten MATLAB code to extract the orientation of membranes from the image gradient and their alignment (coherency). This analysis was used to quantify the POS morphology of wild-type and two inherited retinal degeneration ("retinal degeneration 19" and "rhodopsin knock-out") mouse lines. Both automated analysis technologies provided robust characterization and quantification of POS based on LM or TEM images. Automated image segmentation by the classifier QuaPOS-LM and analysis of the orientation of membrane stacks by QuaPOS-TEM using fluorescent or TEM images allowed quantitative evaluation of POS formation and quality. The assessments showed an increase in POS number, volume, and membrane coherency during wild-type postnatal development, while a decrease in all three observables was detected in different retinal degeneration mouse models. All the code used for the presented analysis is open source, including example datasets to reproduce the findings. Hence, the QuaPOS quantification methods are useful for in-depth characterization of POS on retinal sections in developmental studies, for disease modeling, or after therapeutic interventions affecting photoreceptors. [ABSTRACT FROM AUTHOR]

Chronic inflammation is a constitutive component of many age-related diseases, including age-related macular degeneration (AMD). Here, we identified interleukin-1 receptor–associated kinase M (IRAK-M) as a key immunoregulator in retinal pigment epithelium (RPE) that declines during the aging process. Rare genetic variants of IRAK3, which encodes IRAK-M, were associated with an increased likelihood of developing AMD. In human samples and mouse models, IRAK-M abundance in the RPE declined with advancing age or exposure to oxidative stress and was further reduced in AMD. Irak3-knockout mice exhibited an increased incidence of outer retinal degeneration at earlier ages, which was further exacerbated by oxidative stressors. The absence of IRAK-M led to a disruption in RPE cell homeostasis, characterized by compromised mitochondrial function, cellular senescence, and aberrant cytokine production. IRAK-M overexpression protected RPE cells against oxidative or immune stressors. Subretinal delivery of adeno-associated virus (AAV)–expressing human IRAK3 rescued light-induced outer retinal degeneration in wild-type mice and attenuated age-related spontaneous retinal degeneration in Irak3-knockout mice. Our data show that replenishment of IRAK-M in the RPE may redress dysregulated pro-inflammatory processes in AMD, suggesting a potential treatment for retinal degeneration. Editor's summary: Age-related macular degeneration (AMD) progression is associated with chronic inflammation, but the role of the Myddosome complex, which is necessary for Toll-like receptor and IL-1R signaling, in AMD has not been fully elucidated. Here, Liu and colleagues identified rare variants in IRAK3, which encodes the inhibitory Myddosome component IRAK-M, as being associated with an increased risk of late AMD. Using human retinal samples and mouse models of aging and retinal injury, as well as Irak3-knockout mice, the authors showed that IRAK-M was present in retinal pigment epithelium (RPE) and decreased with age and injury. Overexpression of human IRAK3 in the RPE could attenuate outer retinal degeneration in these mouse models, suggesting a potential therapeutic strategy for AMD. —Melissa L. Norton [ABSTRACT FROM AUTHOR]

While dysfunction and death of light-detecting photoreceptor cells underlie most inherited retinal dystrophies, knowledge of the species-specific details of human rod and cone photoreceptor cell development remains limited. Here, we generated retinal organoids carrying retinal disease-causing variants in NR2E3, as well as isogenic and unrelated controls. Organoids were sampled using single-cell RNA sequencing (scRNA-Seq) across the developmental window encompassing photoreceptor specification, emergence, and maturation. Using scRNA-Seq data, we reconstruct the rod photoreceptor developmental lineage and identify a branch point unique to the disease state. We show that the rod-specific transcription factor NR2E3 is required for the proper expression of genes involved in phototransduction, including rhodopsin, which is absent in divergent rods. NR2E3-null rods additionally misexpress several cone-specific phototransduction genes. Using joint multimodal single-cell sequencing, we further identify putative regulatory sites where rod-specific factors act to steer photoreceptor cell development. Finally, we show that rod-committed photoreceptor cells form and persist throughout life in a patient with NR2E3-associated disease. Importantly, these findings are strikingly different from those observed in Nr2e3 rodent models. Together, these data provide a road map of human photoreceptor development and leverage patient induced pluripotent stem cells to define the specific roles of rod transcription factors in photoreceptor cell emergence and maturation in health and disease. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) with verteporfin involves intravenous administration of a photosensitizer followed by its laser light activation at the target site to inhibit aberrant choroidal vascularization. This narrative review provides an overview of the role verteporfin PDT plays in the management of chorioretinal conditions. A PubMed literature review of all English-language articles published through October 19, 2023, was conducted to identify relevant references. Verteporfin PDT has been shown to be safe and effective for the treatment of patients with choroidal neovascularization (CNV) due to neovascular age-related macular degeneration and is often used in combination with a vascular endothelial growth factor (VEGF) inhibitor. Additionally, patients with polypoidal choroidal vasculopathy, a subtype of neovascular age-related macular degeneration, also benefit from verteporfin PDT combined with a VEGF inhibitor for improving visual acuity. Verteporfin PDT has also been effective in treating patients with peripapillary CNV, as well as eyes with CNV due to ocular histoplasmosis and pathologic myopia. Reduced dose and/or fluence PDT protocols have been effective in patients with central serous chorioretinopathy while reducing adverse effects. In eyes with choroidal hemangioma, tumor regression and visual outcomes have been improved with verteporfin PDT treatment. Photodynamic therapy with verteporfin continues to play an important role in the management of chorioretinal conditions. [ABSTRACT FROM AUTHOR]

Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy (EOSRD) stand as primary causes of incurable childhood blindness. This study investigates the clinical and molecular architecture of syndromic and non-syndromic LCA/EOSRD within a Chilean cohort (67 patients/60 families). Leveraging panel sequencing, 95.5% detection was achieved, revealing 17 genes and 126 variants (32 unique). CRB1, LCA5, and RDH12 dominated (71.9%), with CRB1 being the most prevalent (43.8%). Notably, four unique variants (LCA5 p.Glu415*, CRB1 p.Ser1049Aspfs*40 and p.Cys948Tyr, RDH12 p.Leu99Ile) constituted 62.7% of all disease alleles, indicating their importance for targeted analysis in Chilean patients. This study underscores a high degree of inbreeding in Chilean families affected by pediatric retinal blindness, resulting in a limited mutation repertoire. Furthermore, it complements and reinforces earlier reports, indicating the involvement of ADAM9 and RP1 as uncommon causes of LCA/EOSRD. These data hold significant value for patient and family counseling, pharmaceutical industry endeavors in personalized medicine, and future enrolment in gene therapy-based treatments, particularly with ongoing trials (LCA5) or advancing preclinical developments (CRB1 and RDH12). [ABSTRACT FROM AUTHOR]

Mutations in the retinal pigment epithelial 65 kilodalton protein (RPE65) gene are associated with various inherited retinal diseases (IRDs), including Leber congenital amaurosis (LCA), early-onset severe retinal dystrophy (EOSRD), and retinitis pigmentosa (RP). We screened for mutations in RPE65 in a series of Indian patients with these IRDs to determine the frequency/types of mutations and to describe the associated phenotypes. Diagnosis of LCA, EOSRD, and RP was made by standard and pre-defined criteria. Patients were evaluated by clinical, retinal imaging, and electrophysiological parameters. Genomic DNA from patients and available family members were used for identifying mutations by direct Sanger sequencing of the RPE65 gene or targeted NGS gene panel for IRDs covering 260+ genes. Variations detected were tested in healthy control populations and for co-segregation with the disease in available family members. Mutations were found in eight patients, out of 220 total cases screened, all homozygous for the respective mutant alleles. Seven patients had mutations leading to premature termination codons and one patient had a missense change. The onset of visual loss ranged from birth to <2 years of life. At presentation, RPE mottling in the background retina was present in all cases with macular involvement in five cases with or without vascular attenuation and optic disc pallor. RPE65 mutations in this series were found in 3.6% of cases associated with severe, early-onset disease, with consistent RPE mottling and variable manifestations with regard to the extent of disc pallor, arteriolar attenuation, and appearance of the macula. [ABSTRACT FROM AUTHOR]

Biallelic variants in RTN4IP1 are a well-established cause of syndromic and nonsyndromic early-onset autosomal recessive optic neuropathy. They have more recently been reported to cause a concomitant but later-onset rod-cone dystrophy with or without syndromic features. A comprehensive evaluation was performed that included assessment of visual and retinal function, clinical examination, and retinal imaging. Childhood ophthalmic records as well as the results of genetic testing were evaluated. A 24-year-old female described longstanding reduced visual acuity with more recent subjective impairment of dark adaptation. Visual acuity was subnormal in both eyes. Goldmann kinetic perimetry demonstrated scotomas in a pattern consistent with the presence of both optic neuropathy and rod-cone dystrophy with fundus exam as well as retinal imaging showing corroborating findings. Full-field electroretinography further confirmed the presence of a rod-cone dystrophy. Genetic testing demonstrated biallelic variants in RTN4IP1, one of which was novel, in association with the ocular findings. RTN4IP1-associated early-onset bilateral optic neuropathy with rod-cone dystrophy is a recently described clinical entity with limited reports available to-date. The present case provides additional support for this dual phenotype and identifies a novel causative variant. [ABSTRACT FROM AUTHOR]

Inherited retinal diseases (IRDs) represent a frequent cause of blindness in children and adults. As a consequence of the phenotype and genotype heterogeneity of the disease, it is difficult to have a specific diagnosis without molecular testing. To date, over 340 genes and loci have been associated with IRDs. We present the molecular finding of 191 individuals with IRD, analyzed by targeted next-generation sequencing (NGS). For 67 of them, we performed a family segregation study, considering a total of 126 relatives. A total of 359 variants were identified, 44 of which were novel. Genetic diagnostic yield was 41%. However, after stratifying the patients according to their clinical suspicion, diagnostic yield was higher for well-characterized diseases such as Stargardt disease (STGD), at 65%, and for congenital stationary night blindness 2 (CSNB2), at 64%. Diagnostic yield was higher in the patient group where family segregation analysis was possible (68%) and it was higher in younger (55%) than in older patients (33%). The results of this analysis demonstrated that targeted NGS is an effective method for establishing a molecular genetic diagnosis of IRDs. Furthermore, this study underlines the importance of segregation studies to understand the role of genetic variants with unknow pathogenic role. [ABSTRACT FROM AUTHOR]

The retinal features of Bardet–Biedl syndrome (BBS) are insufficiently characterized in Arab populations. This retrospective study investigated the retinal features and genotypes of BBS in Saudi patients managed at a single tertiary eye care center. Data analysis of the identified 46 individuals from 31 families included visual acuity (VA), systemic manifestations, multimodal retinal imaging, electroretinography (ERG), family pedigrees, and genotypes. Patients were classified to have cone–rod, rod–cone, or generalized photoreceptor dystrophy based on the pattern of macular involvement on the retinal imaging. Results showed that nyctalopia and subnormal VA were the most common symptoms with 76% having VA ≤ 20/200 at the last visit (age: 5–35). Systemic features included obesity 91%, polydactyly 56.5%, and severe cognitive impairment 33%. The predominant retinal phenotype was cone–rod dystrophy 75%, 10% had rod–cone dystrophy and 15% had generalized photoreceptor dystrophy. ERGs were undetectable in 95% of patients. Among the 31 probands, 61% had biallelic variants in BBSome complex genes, 32% in chaperonin complex genes, and 6% had biallelic variants in ARL6; including six previously unreported variants. Interfamilial and intrafamilial variabilities were noted, without a clear genotype–phenotype correlation. Most BBS patients had advanced retinopathy and were legally blind by early adulthood, indicating a narrow therapeutic window for rescue strategies. [ABSTRACT FROM AUTHOR]

Inherited cone disorders (ICDs) are a heterogeneous sub-group of inherited retinal disorders (IRDs), the leading cause of sight loss in children and working-age adults. ICDs result from the dysfunction of the cone photoreceptors in the macula and manifest as the loss of colour vision and reduced visual acuity. Currently, 37 genes are associated with varying forms of ICD; however, almost half of all patients receive no molecular diagnosis. This review will discuss the known ICD genes, their molecular function, and the diseases they cause, with a focus on the most common forms of ICDs, including achromatopsia, progressive cone dystrophies (CODs), and cone–rod dystrophies (CORDs). It will discuss the gene-specific therapies that have emerged in recent years in order to treat patients with some of the more common ICDs. [ABSTRACT FROM AUTHOR]

Remodeling retinal Müller glial fate, including gliosis inhibition and pro-reprogramming, represents a crucial avenue for treating degenerative retinal diseases. Stem cell transplantation exerts effects on modulating retinal Müller glial fate. However, the optimized stem cell products and the underlying therapeutic mechanisms need to be investigated. In the present study, we found that retinal progenitor cells from human embryonic stem cell-derived retinal organoids (hERO-RPCs) transferred extracellular vesicles (EVs) into Müller cells following subretinal transplantation into RCS rats. Small EVs from hERO-RPCs (hERO-RPC-sEVs) were collected and were found to delay photoreceptor degeneration and protect retinal function in RCS rats. hERO-RPC-sEVs were taken up by Müller cells both in vivo and in vitro, and inhibited gliosis while promoting early dedifferentiation of Müller cells. We further explored the miRNA profiles of hERO-RPC-sEVs, which suggested a functional signature associated with neuroprotection and development, as well as the regulation of stem cell and glial fate. Mechanistically, hERO-RPC-sEVs might regulate the fate of Müller cells by miRNA-mediated nuclear factor I transcription factors B (NFIB) downregulation. Collectively, our findings offer novel mechanistic insights into stem cell therapy and promote the development of EV-centered therapeutic strategies. [Display omitted] • hERO-RPC-sEVs protect the retinal structure and visual function of RCS rats after transplantation. • hERO-RPC-sEVs are transferred into Müller cells, inhibiting gliosis and promoting dedifferentiation after transplantation. • miRNA profiles of hERO-RPC-sEVs indicate a functional signature linked to stem/glial cell fate regulation. • hERO-RPC-sEVs remodel Müller cell fate via miRNA-mediated NFIB downregulation. [ABSTRACT FROM AUTHOR]

Given the absence of approved treatments for pathogenic variants in Peripherin-2 (PRPH2), it is imperative to identify a universally effective therapeutic target for PRPH2 pathogenic variants. To test the hypothesis that formation of the elongated discs in presence of PRPH2 pathogenic variants is due to the presence of the full complement of rhodopsin in absence of the required amounts of functional PRPH2. Here we demonstrate the therapeutic potential of reducing rhodopsin levels in ameliorating disease phenotype in knockin models for p.Lys154del (c.458-460del) and p.Tyr141Cys (c.422 A > G) in PRPH2. Reducing rhodopsin levels improves physiological function, mitigates the severity of disc abnormalities, and decreases retinal gliosis. Additionally, intravitreal injections of a rhodopsin-specific antisense oligonucleotide successfully enhance the physiological function of photoreceptors and improves the ultrastructure of discs in mutant mice. Presented findings shows that reducing rhodopsin levels is an effective therapeutic strategy for the treatment of inherited retinal degeneration associated with PRPH2 pathogenic variants. Due to the abundance of pathogenic variants in Peripherin-2, causing peripherin-2-associated inherited retinal disorders, and the lack of any approved treatment, it is imperative to identify an effective therapeutic strategy. Here the authors show that reducing rhodopsin levels improves retinal function and structure and decreases inflammatory responses. [ABSTRACT FROM AUTHOR]

In recent decades, there have been significant advances in the field of Artificial intelligence (AI), retinal imaging, and therapeutics. The specialty of retina generates huge datasets, which are ideally suited to create robust AI models for early detection, diagnosis, classification, and treatment of retinal diseases. Basic aspects of AI algorithms, machine learning models, application of AI in diabetic retinopathy (DR), retinopathy of prematurity (ROP), retinal vascular occlusion (RVO) and age-related macular degeneration (AMD) have been described, highlighting findings from important studies. Comprehensive search of indexed medical literature on Medline/PubMed and Google Scholar databases. The search terms included artificial intelligence, deep learning, machine learning in DR, AMD, ROP, retinal vascular disease, and RVO. The manuscripts published in English literature in the last two decades were selected for this review. Several AI algorithms have been developed which are accurate and efficacious in screening, detecting, diagnosing, and aiding in managing patients with various retinal diseases. Proper external validation using large datasets and establishing their accuracy is central to increasing the confidence and acceptance of these algorithms. The application of AI to screening models can be a boon in many environments, but particularly resource-depleted settings. [ABSTRACT FROM AUTHOR]

Advances in gene therapy and genome editing give hope that new treatments will soon be available for inherited eye diseases that together affect a significant proportion of the adult population. New solutions are needed to make genetic diagnosis fast and affordable. This is the first study of such a large group of patients with inherited retinal dystrophies (IRD) and inherited optic neuropathies (ION) in the Polish population. It is based on four years of diagnostic analysis using a broad, targeted NGS approach. The results include the most common pathogenic variants, as well as 91 novel causative variants, including frameshifts in the cumbersome RPGR ORF15 region. The high frequency of the ABCA4 complex haplotype p.(Leu541Pro;Ala1038Val) was confirmed. Additionally, a deletion of exons 22–24 in USH2A, probably specific to the Polish population, was uncovered as the most frequent copy number variation. The diagnostic yield of the broad NGS panel reached 64.3% and is comparable to the results reported for genetic studies of IRD and ION performed for other populations with more extensive WES or WGS methods. A combined approach to identify genetic causes of all known diseases manifesting in the posterior eye segment appears to be the optimal choice given the currently available treatment options and advanced clinical trials. [ABSTRACT FROM AUTHOR]

PurposeTo describe cone structure changes using adaptive optics scanning laser ophthalmoscopy (AOSLO) in the Rate of Progression of USH2A-related Retinal Degeneration (RUSH2A) study.DesignMulticenter, longitudinal natural history study.MethodsAOSLO images were acquired at 4 centers, twice at baseline and annually for 24 months in this natural history study. For each eye, at least 10 regions of interest (ROIs) with ≥50 contiguous cones were analyzed by masked, independent graders. Cone spacing Z-scores, standard deviations from the normal mean at the measured location, were compared between graders and tests at baseline. The association of cone spacing with clinical characteristics was assessed using linear mixed effects regression models weighted by image quality score. Annual rates of change were calculated based on differences between visits.ResultsFourteen eyes of 14 participants were imaged, with 192 ROIs selected at baseline. There was variability among graders, which was greater in images with lower image quality score (P < .001). Cone spacing was significantly correlated with eccentricity, quality score, and disease duration (P < .02). On average, the cone spacing Z-score increased 0.14 annually (about 9%, P < .001). We observed no significant differences in rate of change between disease type (Usher syndrome or retinitis pigmentosa), imaging site, or grader.ConclusionsUsing current methods, the analysis of quantitative measures of cone structure showed some challenges, yet showed promise that AOSLO images can be used to characterize progressive change over 24 months. Additional multicenter studies using AOSLO are needed to advance cone mosaic metrics as sensitive outcome measures for clinical trials. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

PurposeTo measure photoreceptor packing density and S-cone spatial resolution as a function of retinal eccentricity in patients with enhanced S-cone syndrome (ESCS) and to discuss the possible mechanisms supporting their supernormal S-cone acuity.MethodsWe used an adaptive optics scanning laser ophthalmoscope (AOSLO) to characterize photoreceptor packing. A custom non-AO display channel was used to measure L/M- and S-cone-mediated visual acuity during AOSLO imaging. Acuity measurements were obtained using a four-alternative, forced-choice, tumbling E paradigm along the temporal meridian between the fovea and 4° eccentricity in five of six patients and in seven control subjects. L/M acuity was tested by presenting long-pass-filtered optotypes on a black background, excluding wavelengths to which S-cones are sensitive. S-cone isolation was achieved using a two-color, blue-on-yellow chromatic adaptation method that was validated on three control subjects.ResultsInter-cone spacing measurements revealed a near-uniform cone density profile (ranging from 0.9-1.5 arcmin spacing) throughout the macula in ESCS. For comparison, normal cone density decreases by a factor of 14 from the fovea to 6°. Cone spacing of ESCS subjects was higher than normal in the fovea and subnormal beyond 2°. Compared to the control subjects (n = 7), S-cone-mediated acuities in patients with ESCS were normal near the fovea and became increasingly supernormal with retinal eccentricity. Beyond 2°, S-cone acuities were superior to L/M-cone-mediated acuity in the ESCS cohort, a reversal of the trend observed in normal retinas.ConclusionsHigher than normal parafoveal cone densities (presumably dominated by S-cones) confer better than normal S-cone-mediated acuity in ESCS subjects.

Kai Yaos group used prime editing to repair a blindness-causing mutation in the Pde6b gene in the mouse retina. This breakthrough was made possible by a Cas9 nickase that is not constrained by a protospacer adjacent motif (PAM) sequence requirement. This innovation brings prime editing technology one step closer to correcting disease-causing mutations at will.

PurposeTo evaluate disease progression using static perimetry (SP) in patients with USH2A-related retinal degeneration, including Usher syndrome type 2 (USH2) and nonsyndromic autosomal recessive retinitis pigmentosa.DesignProspective, observational cohort study.MethodsA total of 102 patients with biallelic disease-causing sequence variants in USH2A with baseline best-corrected visual acuity (BCVA) letter score ≥54 were recruited from 16 clinical sites in Europe and North America. SP, BCVA, full-field stimulus thresholds, spectral domain optical coherence tomography macular scans, and fundus-guided mesopic microperimetry were performed at baseline and annually. The main outcome measures were total hill of vision (VTOT), hill of vision in the central 30° (V30), VTOT minus V30 (VPERIPH), and mean sensitivity.ResultsThe average decline (95% CI) was 2.05 (1.40, 2.70) decibel-steradian (dB-sr)/y for VTOT, 0.48 (0.32, 0.65) dB-sr/y for V30, 1.53 (0.97, 2.08) dB-sr/y for VPERIPH, and 0.55 (0.40, 0.71) dB/y for mean sensitivity. Average percentage decline per year was 8.3 (5.5, 11.1) for VTOT, 5.2 (3.0, 7.4) for V30, 16.0 (9.5, 22.0) for VPERIPH, and 5.1 (3.5, 6.7) for mean sensitivity. Changes from baseline to year 2 in all SP measures were highly correlated (r's ranging from 0.52 [V30 vs VPERIPH] to 0.98 [VTOT vs VPERIPH]).ConclusionsQuantitative measures of SP declined significantly over 2 years in USH2A-related retinal degeneration. The annual percentage rate of change was greatest for VTOT and VPERIPH, whereas V30 and mean sensitivity changed least, reflecting earlier and more severe peripheral degeneration compared with central loss.

Retinitis Pigmentosa (RP) is a heterogenous group of inherited disorder, and its progression not only affects the retina but also the primary visual cortex. This manifests imbalances in the excitatory and inhibitory neurotransmission. Here, we investigated if changes in cortical functioning is linked to alterations in GABAergic population of neurons and its two important subsets, somatostatin (SST) and parvalbumin (PV) neuron in rd1 model of retinal degeneration (RD). We demonstrate marked decrease in the proportion of SST neurons in different layers of cortex whereas PV neurons were less affected. Moreover, we found reduced expression of glutamatergic thalamic afferents (VGLUT2) due to lack of visual activity. These results suggest PV neurons are likely recruited by the cortical circuitry to increase the inhibitory drive and compensate the disrupted inhibition-excitation balance. However, reduced SST expression perhaps results in weakening of stimulus selectivity. Delineating their functional role during RD will provide insights for acquisition of high-resolution vision thereby improving current state of vision restoration.

This correction notice addresses errors in a scientific article titled "Caspase-1-dependent inflammasomes mediate photoreceptor cell death in photo-oxidative damage-induced retinal degeneration." The errors involve the use of the same group of wildtype mice as a comparison to multiple knockout models in several figures. The corrected information shows that Caspase1/11−/− mice have better-preserved retinal function and reduced inflammation and cell death following photo-oxidative damage compared to wildtype controls. Similarly, Nlrp3−/− mice show better-preservation of retinal function following photo-oxidative damage compared to wildtype controls. On the other hand, Casp11−/− mice show no preservation of retinal function following photo-oxidative damage. The correction also addresses errors in the legends of Supplementary Figures 1, 2, and 3, clarifying that the wildtype controls used in these figures are the same as in other figures. [Extracted from the article]

Chronic, progressive retinal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa, arise from genetic and environmental perturbations of cellular and tissue homeostasis. These disruptions accumulate with repeated exposures to stress over time, leading to progressive visual impairment and, in many cases, legal blindness. Despite decades of research, therapeutic options for the millions of patients suffering from these disorders remain severely limited, especially for treating earlier stages of pathogenesis when the opportunity to preserve the retinal structure and visual function is greatest. To address this urgent, unmet medical need, we employed a systems pharmacology platform for therapeutic development. Through integrative single-cell transcriptomics, proteomics, and phosphoproteomics, we identified universal molecular mechanisms across distinct models of age-related and inherited retinal degenerations, characterized by impaired physiological resilience to stress. Here, we report that selective, targeted pharmacological inhibition of cyclic nucleotide phosphodiesterases (PDEs), which serve as critical regulatory nodes that modulate intracellular second messenger signaling pathways, stabilized the transcriptome, proteome, and phosphoproteome through downstream activation of protective mechanisms coupled with synergistic inhibition of degenerative processes. This therapeutic intervention enhanced resilience to acute and chronic forms of stress in the degenerating retina, thus preserving tissue structure and function across various models of age-related and inherited retinal disease. Taken together, these findings exemplify a systems pharmacology approach to drug discovery and development, revealing a new class of therapeutics with potential clinical utility in the treatment or prevention of the most common causes of blindness.

Gene augmentation and genome editing are promising strategies for the treatment of monogenic inherited retinal diseases. Although gene augmentation treatments are commercially available for inherited retinal diseases, there are many shortcomings that need to be addressed, like progressive retinal degeneration and diminishing efficacy over time. Innovative CRISPR-Cas9-based genome editing technologies have broadened the proportion of treatable genetic disorders and can greatly improve or complement treatment outcomes from gene augmentation. Progress in this relatively new field involves the development of therapeutics including gene disruption, ablate-and-replace strategies, and precision gene correction techniques, such as base editing and prime editing. By making direct edits to endogenous DNA, genome editing theoretically guarantees permanent gene correction and long-lasting treatment effects. Improvements to delivery modalities aimed at limiting persistent gene editor activity have displayed an improved safety profile and minimal off-target editing. Continued progress to advance precise gene correction and associated delivery strategies will establish genome editing as the preferred treatment for genetic retinal disorders. This commentary describes the applications, strengths, and drawbacks of conventional gene augmentation approaches, recent advances in precise genome editing in the retina, and promising preclinical strategies to facilitate the use of robust genome editing therapies in human patients.

PurposeThe unfolded protein response (UPR) is triggered when the protein folding capacity of the endoplasmic reticulum (ER) is overwhelmed and misfolded proteins accumulate in the ER, a condition referred to as ER stress. IRE1α is an ER-resident protein that plays major roles in orchestrating the UPR. Several lines of evidence implicate the UPR and its transducers in neurodegenerative diseases, including retinitis pigmentosa (RP), a group of inherited diseases that cause progressive dysfunction and loss of rod and cone photoreceptors. This study evaluated the contribution of IRE1α to photoreceptor development, homeostasis, and degeneration.MethodsWe used a conditional gene targeting strategy to selectively inactivate Ire1α in mouse rod photoreceptors. We used a combination of optical coherence tomography (OCT) imaging, histology, and electroretinography (ERG) to assess longitudinally the effect of IRE1α deficiency in retinal development and function. Furthermore, we evaluated the IRE1α-deficient retina responses to tunicamycin-induced ER stress and in the context of RP caused by the rhodopsin mutation RhoP23H.ResultsOCT imaging, histology, and ERG analyses did not reveal abnormalities in IRE1α-deficient retinas up to 3 months old. However, by 6 months of age, the Ire1α mutant animals showed reduced outer nuclear layer thickness and deficits in retinal function. Furthermore, conditional inactivation of Ire1α in rod photoreceptors accelerated retinal degeneration caused by the RhoP23H mutation.ConclusionsThese data suggest that IRE1α is dispensable for photoreceptor development but important for photoreceptor homeostasis in aging retinas and for protecting against ER stress-mediated photoreceptor degeneration.

Most defects causing retinal degeneration in retinitis pigmentosa (RP) are rod-specific mutations, but the subsequent degeneration of cones, which produces loss of daylight vision and high-acuity perception, is the most debilitating feature of the disease. To understand better why cones degenerate and how cone vision might be restored, we have made the first single-cell recordings of light responses from degenerating cones and retinal interneurons after most rods have died and cones have lost their outer-segment disk membranes and synaptic pedicles. We show that degenerating cones have functional cyclic-nucleotide-gated channels and can continue to give light responses, apparently produced by opsin localized either to small areas of organized membrane near the ciliary axoneme or distributed throughout the inner segment. Light responses of second-order horizontal and bipolar cells are less sensitive but otherwise resemble those of normal retina. Furthermore, retinal output as reflected in responses of ganglion cells is less sensitive but maintains spatiotemporal receptive fields at cone-mediated light levels. Together, these findings show that cones and their retinal pathways can remain functional even as degeneration is progressing, an encouraging result for future research aimed at enhancing the light sensitivity of residual cones to restore vision in patients with genetically inherited retinal degeneration.

National Eye Institute recently issued a new Strategic Plan outlining priority research areas for the next 5 years. Starting cell source for deriving stem cell lines is as an area with gaps and opportunities for making progress in regenerative medicine, a key area of emphasis within the NEI Strategic Plan. There is a critical need to understand how starting cell source affects the cell therapy product and what specific manufacturing capabilities and quality control standards are required for autologous vs allogeneic stem cell sources. With the goal of addressing some of these questions, in discussion with the community-at-large, NEI hosted a Town Hall at the Association for Research in Vision and Ophthalmology annual meeting in May 2022. This session leveraged recent clinical advances in autologous and allogeneic RPE replacement strategies to develop guidance for upcoming cell therapies for photoreceptors, retinal ganglion cells, and other ocular cell types. Our focus on stem cell-based therapies for RPE underscores the relatively advanced stage of RPE cell therapies to patients with several ongoing clinical trials. Thus, this workshop encouraged lessons learned from the RPE field to help accelerate progress in developing stem cell-based therapies in other ocular tissues. This report provides a synthesis of the key points discussed at the Town Hall and highlights needs and opportunities in ocular regenerative medicine.

Rhodopsin is the critical receptor molecule which enables vertebrate rod photoreceptor cells to detect a single photon of light and initiate a cascade of molecular events leading to visual perception. Recently, it has been suggested that the F45L mutation in the transmembrane helix of rhodopsin disrupts its dimerization in vitro To determine whether this mutation of rhodopsin affects its signaling properties in vivo, we generated knock-in mice expressing the rhodopsin F45L mutant. We then examined the function of rods in the mutant mice versus wild-type controls, using in vivo electroretinography and transretinal and single cell suction recordings, combined with morphologic analysis and spectrophotometry. Although we did not evaluate the effect of the F45L mutation on the state of dimerization of the rhodopsin in vivo, our results revealed that F45L-mutant mice exhibit normal retinal morphology, normal rod responses as measured both in vivo and ex vivo, and normal rod dark adaptation. We conclude that the F45L mutation does not affect the signaling properties of rhodopsin in its natural setting.

Aims/hypothesisAccumulating evidence suggests that leucocytes play a critical role in diabetes-induced vascular lesions and other abnormalities that characterise the early stages of diabetic retinopathy. However, the role of monocytes has yet to be fully investigated; therefore, we used Ccr2-/- mice to study the role of CCR2+ inflammatory monocytes in the pathogenesis of diabetes-induced degeneration of retinal capillaries.MethodsExperimental diabetes was induced in wild-type and Ccr2-/- mice using streptozotocin. After 2 months, superoxide levels, expression of inflammatory genes, leucostasis, leucocyte- and monocyte-mediated cytotoxicity against retinal endothelial cell death, retinal thickness and visual function were evaluated. Retinal capillary degeneration was determined after 8 months of diabetes. Flow cytometry of peripheral blood for differential expression of CCR2 in monocytes was assessed.ResultsIn nondiabetic mice, CCR2 was highly expressed on monocytes, and Ccr2-/- mice lack CCR2+ monocytes in the peripheral blood. Diabetes-induced retinal superoxide, expression of proinflammatory genes Inos and Icam1, leucostasis and leucocyte-mediated cytotoxicity against retinal endothelial cells were inhibited in diabetic Ccr2-deficient mice and in chimeric mice lacking Ccr2 only from myeloid cells. In order to focus on monocytes, these cells were immuno-isolated after 2 months of diabetes, and they significantly increased monocyte-mediated endothelial cell cytotoxicity ex vivo. Monocytes from Ccr2-deficient mice caused significantly less endothelial cell death. The diabetes-induced retinal capillary degeneration was inhibited in Ccr2-/- mice and in chimeric mice lacking Ccr2 only from myeloid cells.Conclusions/interpretationCCR2+ inflammatory monocytes contribute to the pathogenesis of early lesions of diabetic retinopathy.

Abstract For 15 years, gene therapy has been viewed as a beacon of hope for inherited retinal diseases. Many preclinical investigations have centered around vectors with maximal gene expression capabilities, yet despite efficient gene transfer, minimal physiological improvements have been observed in various ciliopathies. Retinitis pigmentosa-type 28 (RP28) is the consequence of bi-allelic null mutations in the FAM161A, an essential protein for the structure of the photoreceptor connecting cilium (CC). In its absence, cilia become disorganized, leading to outer segment collapses and vision impairment. Within the human retina, FAM161A has two isoforms: the long one with exon 4, and the short one without it. To restore CC in Fam161a-deficient mice shortly after the onset of cilium disorganization, we compared AAV vectors with varying promoter activities, doses, and human isoforms. While all vectors improved cell survival, only the combination of both isoforms using the weak FCBR1-F0.4 promoter enabled precise FAM161A expression in the CC and enhanced retinal function. Our investigation into FAM161A gene replacement for RP28 emphasizes the importance of precise therapeutic gene regulation, appropriate vector dosing, and delivery of both isoforms. This precision is pivotal for secure gene therapy involving structural proteins like FAM161A.

Abstract Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss, characterised by the dysfunction and death of the photoreceptors and retinal pigment epithelium (RPE). Innate immune cell activation and accompanying para-inflammation have been suggested to contribute to the pathogenesis of AMD, although the exact mechanism(s) and signalling pathways remain elusive. Pattern recognition receptors (PRRs) are essential activators of the innate immune system and drivers of para-inflammation. Of these PRRs, the two most prominent are (1) Toll-like receptors (TLR) and (2) NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3)-inflammasome have been found to modulate the progression of AMD. Mutations in TLR2 have been found to be associated with an increased risk of developing AMD. In animal models of AMD, inhibition of TLR and NLRP3 has been shown to reduce RPE cell death, inflammation and angiogenesis signalling, offering potential novel treatments for advanced AMD. Here, we examine the evidence for PRRs, TLRs2/3/4, and NLRP3-inflammasome pathways in macular degeneration pathogenesis.