Is It Always Amblyopia?

Abstract

Introduction RS1 gene mutations cause X-linked juvenile retinoschisis (XLRS), a hereditary retinal disorder with progressive vision loss and retinal layer splitting [1,2]. Clinical features vary from macular cysts to peripheral changes, and genotype-phenotype correlations [3,4]. Children with reduced vision or amblyopia unresponsive to correction should be assessed for other ocular causes. Diagnosis requires clinical evaluation and genetic confirmation, with long-term monitoring to guide management and prevent complications [1,3]. Case Presentation A 12-year-old boy with a prior diagnosis of amblyopia and mild intermittent divergent strabismus had suboptimal BCVA despite spectacle correction (BCVA right eye 0.4, left eye 0.3 (Snellen decimal chart)). OCT and fundus examination revealed bilateral macular and peripheral retinoschisis. RS1 gene sequencing (single-gene analysis) revealed hemizygous pathogenic variant NM_000330.4:c.638G>A; p.(Arg213Gln) and XLRS was confirmed. Continuous spectacle use and regular eye follow-up were advised. XLRS is phenotypically variable, sometimes affecting mainly the periphery or showing subtle pigmentary changes, requiring individualized follow-up [3,5]. Discussion This case shows that therapy-resistant amblyopia should prompt detailed structural evaluation. Bilateral macular pathology can be missed without OCT or thorough fundus evaluation. Visual acuity correlates more with outer retinal layer integrity - especially the photoreceptor layer and ellipsoid zone than cyst size [7]. RS1 dysfunction alters retinal architecture and photoreceptor development, with genetic modifiers influencing phenotype [8]. No cure exists, but gene therapy and retinal organoid advances may enable future XLRS treatments [9]. Conclusions In children, amblyopia unresponsive to optimal refractive correction should prompt evaluation for other causes, including hereditary retinal diseases like XLRS, which is heterogeneous, with visual function linked to outer retinal integrity [3,7]. Genetic diagnosis is important for clinicians and parents, and individualized monitoring with OCT, fundus evaluation, and genetic counseling is essential [1,2,5]. Advances in gene therapy and retinal organoid technology may offer future treatment options [8,9].