Familial exudative vitreoretinopathy (FEVR) is a severe retinal vascular disease that causes blindness. FEVR has been linked to mutations in several genes associated with inactivation of the Norrin/β-catenin signaling pathway, but these account for only approximately 50% of cases. We report that mutations in α-catenin (CTNNA1) cause FEVR by overactivating the β-catenin pathway and disrupting cell adherens junctions. We identified 3 heterozygous mutations in CTNNA1 (p.F72S, p.R376Cfs*27, and p.P893L) by exome sequencing and further demonstrated that FEVR-associated mutations led to overactivation of Norrin/β-catenin signaling as a result of impaired protein interactions within the cadherin-catenin complex. The clinical features of FEVR were reproduced in mice lacking Ctnna1 in vascular endothelial cells (ECs) or with overactivated β-catenin signaling by an EC-specific gain-of-function allele of Ctnnb1. In isolated mouse lung ECs, both CTNNA1-P893L and F72S mutants failed to rescue either the disrupted F-actin arrangement or the VE-cadherin and CTNNB1 distribution. Moreover, we discovered that compound heterozygous Ctnna1 F72S and a deletion allele could cause a similar phenotype. Furthermore, in a FEVR family, we identified a mutation of LRP5, which activates Norrin/β-catenin signaling, and the corresponding knockin mice exhibited a partial FEVR-like phenotype. Our study demonstrates that the precise regulation of β-catenin activation is critical for retinal vascular development and provides new insights into the pathogenesis of FEVR.

Retinal detachment (RD) occurs in several major retinal conditions and often causes irreversible vision loss due to photoreceptor cell death. Retinal residential microglial cells are activated following RD and participate in photoreceptor cell death via direct phagocytosis and the regulation of inflammatory responses. Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune receptor exclusively expressed on microglial cells in the retina, and has been reported to affect microglial cell homeostasis, phagocytosis and inflammatory responses in the brain. In this study, increased expression of multiple cytokines and chemokines in the neural retina was observed starting at 3 h following RD. Trem2 knockout (Trem2^−/−) mice exhibited significantly more photoreceptor cell death than wild-type controls at 3 days after RD, and the number of TUNEL positive photoreceptor cells progressively decreased from day 3 to day 7 post-RD. A significant thinning of the outer nuclear layer (ONL), with multiple folds was observed in the Trem2^−/− mice at 3 days post-RD. Trem2 deficiency reduced microglial cell infiltration and phagocytosis of stressed photoreceptors. There were more neutrophils in Trem2^−/− retina following RD than in controls. Using purified microglial cells, we found Trem2 knockout is associated with increased CXCL12 expression. The aggravated photoreceptor cell death was largely reversed by blocking the CXCL12-CXCR4 mediated chemotaxis in Trem2^−/− mice after RD. Our findings suggested that retinal microglia are protective in preventing further photoreceptor cell death following RD by phagocytosing presumably stressed photoreceptor cells and by regulating inflammatory responses. TREM2 is largely responsible for such protective effect and CXCL12 plays an important role in regulating neutrophil infiltration after RD. Collectively, our study pinpointed TREM2 as a potential target of microglial cells to ameliorate RD-induced photoreceptor cell death.

Purpose: Early detection of ocular abnormalities in newborns is essential for timely diagnosis and treatment. This study aimed to assess the 1‐year result of a multicentre prospective neonatal eye examination programme with wide‐field digital imaging system in China.Methods: A multicentre collaborative prospective study group for neonatal eye screening was established in nine hospitals, including eight Maternal and Children's Hospitals, and one general hospital across China from July 2016 to June 2017. Ocular examinations were performed on newborns within 28 days after birth using a wide‐field digital imaging system. Data were reviewed and analysed. The primary outcome was the prevalence of ocular abnormalities in neonates.Results: We detected 13 514 (20.91%) abnormal cases in 64 632 newborns. The most frequent abnormality was retinal haemorrhage (RH; 11.83%). Most of mild RH resolved spontaneously. Among those who were beyond retinopathy of prematurity (ROP) screening criteria of China (gestational age ≥32 w and birthweight ≥2000 g), the total number of neonates with ocular abnormality was 12 218/62 799(19.45%). 59.44% of neonatal ocular abnormalities detected (accounting for 11.56% of all the screened population) needed further interference or observation. Among them, 258 patients (0.41% of all the screened population) needed immediate or timely intervention, including congenital cataract, retinal detachment, retinoblastoma and other ocular abnormalities. One thousand and ninety‐eight patients (1.75% of all the screened neonates) should be followed up closely and needed further diagnosis or intervention if necessary, such as ROP or ROP‐like retinopathy, familial exudative vitreoretinopathy and persistent hyperplasia of primary vitreous. Five thousand nine hundred and six patients (9.4%) with minor clinical significance needed short‐term follow‐up.Conclusions: This prospective multicentre study of newborn ocular examination showed a relatively high prevalence of ocular abnormalities. There are a relatively high percentage of congenital eye pathology that required further referral and treatment in those neonates who were not screened routinely. According to the benefits and risks associated with neonatal eye examinations, neonatal ocular screening programme can detect ocular abnormalities at the very early stage and may play a positive role in promoting paediatric eye health.

Background Large language models (LLMs), such as ChatGPT, have considerable implications for various medical applications. However, ChatGPT’s training primarily draws from English-centric internet data and is not tailored explicitly to the medical domain. Thus, an ophthalmic LLM in Chinese is clinically essential for both healthcare providers and patients in mainland China. Methods We developed an LLM of ophthalmology (MOPH) using Chinese corpora and evaluated its performance in three clinical scenarios: ophthalmic board exams in Chinese, answering evidence-based medicine-oriented ophthalmic questions and diagnostic accuracy for clinical vignettes. Additionally, we compared MOPH’s performance to that of human doctors. Results In the ophthalmic exam, MOPH’s average score closely aligned with the mean score of trainees (64.7 (range 62–68) vs 66.2 (range 50–92), p=0.817), but achieving a score above 60 in all seven mock exams. In answering ophthalmic questions, MOPH demonstrated an adherence of 83.3% (25/30) of responses following Chinese guidelines (Likert scale 4–5). Only 6.7% (2/30, Likert scale 1–2) and 10% (3/30, Likert scale 3) of responses were rated as ‘poor or very poor’ or ‘potentially misinterpretable inaccuracies’ by reviewers. In diagnostic accuracy, although the rate of correct diagnosis by ophthalmologists was superior to that by MOPH (96.1% vs 81.1%, p>0.05), the difference was not statistically significant. Conclusion This study demonstrated the promising performance of MOPH, a Chinese-specific ophthalmic LLM, in diverse clinical scenarios. MOPH has potential real-world applications in Chinese-language ophthalmology settings.

Purpose: Familial exudative vitreoretinopathy (FEVR) is a blinding retinal vascular disease. Clinically, FEVR is characterized by incomplete vascularization of the peripheral retina and pathological neovascularization. Only about 50% of FEVR cases can be explained by known FEVR disease gene variations. This study aimed to identify novel genes associated with the FEVR phenotype and explore their pathogenic mechanisms. Materials and Methods: Exome sequencing analyses were conducted on one Chinese family with FEVR whose affected members did not exhibit pathogenic variants in the known FEVR genes (verified using Sanger sequencing analysis). Functions of the affected proteins were evaluated using reporter assays. Western blot analysis was used to detect mutant protein expression and the genes' pathogenic mechanisms. Results: A rare novel heterozygous variant in DLG1 (c.1792A>G; p.S598G) was identified. The amino acid residues surrounding the identified variant are highly conserved among vertebrates. A luciferase reporter assay revealed that the mutant DLG1 protein DLG1 -S598G lost its ability to activate Wnt signaling. Moreover, a knockdown (KD) of DLG1 in human primary retinal endothelial cells impaired tube formation. Mechanistically, DLG1 KD led to a reduction in phosphorylated VEGFR2, an essential receptor for the angiogenic potency that signals the vascular endothelial growth factor molecule. Conclusions: The data reported here demonstrate that DLG1 is a novel candidate gene for FEVR.

Aims: To explore the clinical and genetical features of families with strictly confirmed familial exudative vitreoretinopathy (FEVR) in a large Chinese cohort.Methods: A retrospective chart review study was conducted on the FEVR families diagnosed by both angiography and targeted next-generation sequencing in six FEVR known genes (FZD4, LRP5, TSPAN12, NDP, KIF11, ZNF408) in the probands and at least one first-degree family member. Variation in expressivity and severity was evaluated in different gene groups.Results: 105 FEVR families (223 FEVR affected subjects with 434 eyes) met the inclusion criteria. There were 105 probands with mean age of 3.8 years old and 118 affected family members of 32.7 years old averagely. Mutations in FZD4 were most prevalent (33.33%), followed by LRP5 (29.52%), TSPAN12 (22.86%), NDP (5.71%), KIF11 (1.9%) and ZNF408 (0.95%). 81% of the probands were classified as stage 4 or worse which most prevalently contributed to FZD4 mutations. All of the three affected family members with stage 4 or worse carried FZD4 variants. More than half (51.43%) of the probands in FZD4 group showed asymmetry. Unilateral FEVR was detected in 11 (10.5%) families consisting of six probands and six affected relatives, and FZD4 mutations accounted for 63.64% of all the cases with variant (c.1282_1285del, p. D428fs) identified in three families.Conclusions: Genotype-phenotype correlation in FEVR was complex with family dependent. Mutations in FZD4 might initiate the most diverse and asymmetric phenotypes.