X-linked retinoschisis maculopathy treated with topical dorzolamide, and relationship to genotype

Purpose To correlate the response of topical dorzolamide (Trusopt; Merck) in patients with X-linked retinoschisis (XLRS) with genotype. Methods We carried out a retrospective evaluation of four patients (seven eyes) with XLRS, treated with topical dorzolamide. The change in best-corrected visual acuity (VA) and central macular thickness (CMT; central 1mm subfield thickness) from optical coherence tomography (OCT) was analysed over the follow-up period, using Student's t-test. Each patient also had genetic analysis for mutations in the retinoschisis gene (RS1). Results The mean age at the start of treatment was 14.7 +/- 11 years, and mean follow-up duration was 21.7 +/- 7.7 months. Mean CMT at the final follow-up was significantly better than at baseline (291 +/- 123 vs 352 +/- 119 mu m, P = 0.007); however, mean VA was worse (0.38 +/- 0.25 vs 0.31 +/- 0.24 logMAR score, P = 0.041). All four patients had a mutation in the RS1 gene; there was no apparent association between the type of mutation and the response to topical dorzolamide. Conclusion Topical dorzolamide may have some effect in reducing central macular thickness in patients with XLRS, but this does not necessarily correlate with improvement in VA. In our case series, genotypic information did not predict the response to this treatment. Eye (2011) 25, 922-928; doi: 10.1038/eye.2011.91; published online 29 April 2011