Early Clinical Manifestations and Visual Prognosis of Japanese Patients with Norrie Disease: A Case Series and Literature Review.

Background/Objectives: To characterize the early clinical manifestations and treatment outcomes of Japanese patients with Norrie disease. Retrospective multicenter observational case series with a systematic literature review. Methods: Fourteen infants with genetically confirmed Norrie disease were retrospectively reviewed. Clinical findings, disease stage, interocular asymmetry, treatment, and visual outcomes were evaluated using a modified staging system based on familial exudative vitreoretinopathy (FEVR) and the International Classification of Retinopathy of Prematurity. A systematic review of previously reported Japanese cases was performed to assess disease severity at initial diagnosis. Results: Twenty-eight eyes of 14 patients were included. The median age at the initial examination was 2.5 months. Twenty-three eyes (82%) had stage 5 retinal detachment, whereas only five eyes (18%) had stage 2 or 4 disease. Interocular asymmetry was uncommon. Twenty-one eyes (75%) underwent laser photocoagulation and/or surgery. Visual outcomes were poor; at the most recent follow-up, all but two stage 4 eyes treated with laser photocoagulation had no light perception. Combined analysis of our cohort and the literature review identified 29 Japanese patients from 19 families and demonstrated that most already had advanced bilateral retinal detachment within the first two months of life. Conclusions: Norrie disease typically presents with advanced bilateral retinal detachment during early infancy, leaving limited opportunities for effective intervention. Early recognition and genetic diagnosis are therefore essential.