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Supplemental Digital Content is Available in the Text. Background: This study aims to characterize optic disc hypoplasia in congenital aniridia using ultra-wide-field imaging (UWFI) and nonmydriatic retinal photography (NMRP). We also investigated the relation between optic disc hypoplasia and foveal hypoplasia. Methods: This is a retrospective case series of patients diagnosed with PAX6 -related aniridia in a National Referral Center, who underwent UWFI, NMRP, and spectral-domain optical coherence tomography (SD-OCT). The disc diameter (DD) and the disc-to-fovea distance (DF) were measured. The DD:DF ratio was used to assess the relative size of the optic disc. The analyses were carried with respect to paired age- and sex-matched healthy controls. SD-OCT was used for foveal hypoplasia grading (from 1 to 4) and retinal nerve fiber layer (RNFL) analysis. Results: Mean manual DD:DF ratio was 0.33 (95% CI: 0.31–0.35) in aniridia patients versus 0.37 (95% CI: 0.36–0.39) in control patients (n = 20, P = 0.005) measured on NMRP and 0.32 (95% CI: 0.30–0.35) in aniridia patients versus 0.37 (95% CI: 0.37–0.39) in control patients (n = 26, P < 0.0001) when assessed on UWFI. Mean semiautomated DD:DF ratio measured on UWFI in aniridia patients was 0.31 (95% CI: 0.29–0.33) versus 0.37 (95% CI: 0.36–0.38) in control patients (P < 0.0001). Also, a negative correlation was found significant between the grade of foveal hypoplasia and the mean semiautomated DD:DF ratio (r = −0.52, 95% CI: −0.76 to −0.15, P = 0.0067). Finally, a significant negative correlation was found between the peripapillary temporal RNFL thickness and the grade of foveal hypoplasia (P = 0.0034). Conclusions: The DD:DF ratio is significantly reduced in PAX6 -related aniridia patients and correlates with the severity of foveal hypoplasia. This ratio is a valuable tool for optic disc hypoplasia assessment in congenital aniridia, especially when provided semiautomatically by UWFI. [ABSTRACT FROM AUTHOR]

Early‐onset osteoporosis (EOOP) has been associated with several genes, including LRP5, coding for a coreceptor in the Wnt pathway. Variants in LRP5 were also described in osteoporosis pseudoglioma syndrome, combining severe osteoporosis and eye abnormalities. Genomewide‐association studies (GWAS) showed that LRP5 p.Val667Met (V667M) variant is associated with low bone mineral density (BMD) and increased fractures. However, despite association with a bone phenotype in humans and knockout mice, the impact of the variant in bone and eye remains to be investigated. Here, we aimed to evaluate the bone and ocular impact of the V667M variant. We recruited 11 patients carrying the V667M variant or other loss‐of‐function variants of LRP5 and generated an Lrp5V667M mutated mice. Patients had low lumbar and hip BMD Z‐score and altered bone microarchitecture evaluated by HR‐pQCT compared with an age‐matched reference population. Murine primary osteoblasts from Lrp5V667M mice showed lower differentiation capacity, alkaline phosphatase activity, and mineralization capacity in vitro. Ex vivo, mRNA expression of Osx, Col1, and osteocalcin was lower in Lrp5V667M bones than controls (all p < 0.01). Lrp5V667M 3‐month‐old mice, compared with control (CTL) mice, had decreased BMD at the femur (p < 0.01) and lumbar spine (p < 0.01) with normal microarchitecture and bone biomarkers. However, Lrp5V667M mice revealed a trend toward a lower femoral and vertebral stiffness (p = 0.14) and had a lower hydroxyproline/proline ratio compared with CTL, (p = 0.01), showing altered composition and quality of the bone matrix. Finally, higher tortuosity of retinal vessels was found in the Lrp5V667M mice and unspecific vascular tortuosity in two patients only. In conclusion, Lrp5V667M variant is associated with low BMD and impaired bone matrix quality. Retinal vascularization abnormalities were observed in mice. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. [ABSTRACT FROM AUTHOR]