Enhanced S-cone syndrome in a family: first long-term (12-year) follow-up and literature review

PURPOSE: To describe the long-term clinical course of Enhanced S-cone Syndrome (ESCS) in three siblings carrying the same NR2E3 variant, and to report therapeutic outcomes of choroidal neovascularization (CNV) and cystic macular changes during a 12-year follow-up from early childhood. METHODS: This is a retrospective observational family case with literature review. Three siblings were examined periodically over 12 years beginning in early childhood. Clinical evaluation included best corrected visual acuity (BCVA), cycloplegic refraction, multimodal imaging. CNV was treated with intravitreal ranibizumab, while cystic macular changes were managed with topical carbonic anhydrase inhibitors (CAIs). RESULTS: The three siblings shared a homozygous splice site variant (c.119-2 A > C) in the NR2E3 gene and ERG showed ESCS pathognomonic features. In the eldest brother, acute onset esotropia secondary to visual impairment caused by CNV represented the first clinical manifestation. Following the onset of night blindness between ages 11 and 14, the older brother and sister developed macular cystic changes; however, topical CAIs were ineffective. Notably, they maintained stable visual acuity over a 12-year observation period. CONCLUSION: This family report underscores the clinical variability in ESCS and suggests that the visual acuity of young patients with ESCS remains stable, even in the presence of macular schisis. CNV was successfully treated with two intravitreal injections of ranibizumab, whilst topical CAIs proved ineffective for treating cystic patterns. Additional long-term studies are required to better understand the natural history of ESCS and improve therapeutic strategies.