Long-term Therapy Results of Topical Dorzolamide Treatment in Enhanced S-Cone Syndrome

Background

Enhanced S-cone syndrome (ESCS) is a rare autosomal recessive inherited retinal disorder characterized by abnormal development of the cones [1]. The S-cones are overexpressed, while the L- and M-cones as well as rods are degenerated. This condition is caused by mutation in the NR2E3 gene on the 15q24 chromosome, which has a major impact in regulating the differentiation of photoreceptors [2], [3].

Differentiating ESCS from other retinal dystrophies might be challenging in the early stages, where full-field electroretinography (ffERG) is considered the main diagnostic tool to confirm the diagnosis. The electrodiagnostic hallmarks are a unique amplification of the S-cone signal, as well as decreased or absent scotopic signals in ffERG [3]. The clinical findings may vary depending on the stage of the condition. Among the clinical fundoscopic features, the nummular hyperpigmentations are described and well documented as prominent hypoautofluorescence along the vascular arcades on fundus autofluorescence imaging [4]. Genetic testing is advisable in order to definitively confirm the diagnosis [2].

Affected patients usually suffered night blindness (nyctalopia) since birth [1]. In the phenotypically similar variant Goldmann-Favre syndrome (GFS), a progressive loss of central vision may occur due to schisis-like changes [3]. The aim of this report is to demonstrate the long-term efficacy of the topical dorzolamide treatment approach for the management of foveomacular schisis in ESCS.

Publication History

Received: 26 October 2024

Accepted: 29 November 2024

Article published online:
10 February 2025

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