X-linked retinoschisis (XLRS) is an early onset hereditary retinal dystrophy. It is caused by mutations of the RS1 gene. Common manifestations of XLRS are schitic lesions at the macula, as well as infero-temporal schisis. Carbonic anhydrase inhibitors have previously been shown to reduce intraretinal cystoid spaces. This paper describes the resolution of a mid-peripheral schisis with the use of topical dorzolamide. In this case a 34-year-old male presented with long standing difficulties with both near and distance vision, with a best corrected visual acuity of 20/40-2 in either eye. Spectral domain optical coherence tomography (SD-OCT) demonstrated macular schisis as well as a mid-peripheral schisis. A diagnosis of XLRS was made with a finding of a mutation within the RS1 gene. The patient was treated with 2% topical dorzolamide three times a day, for three months. At three month review, a definite reduction in the intraretinal cystic spaces was found with a reduction in the intraretinal spaces in the mid peripheral retina as well. Vision was not significantly altered, being 20/40+2 in either eye at review. This is the first report of this nature, and demonstrates the potential of using carbonic anhydrase inhibitors in XLRS, and that it may be of at least some use. The correlation with visual function is still unsure.