Efficacy of oral acetazolamide and topical dorzolamide therapy for X-linked juvenile retinoschisis maculopathy

GALANTUOMO, MARIA SILVANA;CUCCU, ALBERTO;ZUCCA, IGNAZIO ALBERTO;Preising M. N.;Lorenz B.;FOSSARELLO, MAURIZIO

2014-01-01

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Abstract

Purpose: To evaluate the response of macular cysts after treatment with acetazolamide tablet or dorzolamide eye drops in 2 brothers with juvenile X-linked retinoschisis (XLRS). Methods: We carried out a retrospective evaluation of two brothers (four eyes) with XLRS, treated with acetazolamide tablet (375 mg daily) for three months, followed by dorzolamide 2% eye drops three times a day for further three months. The change in best-corrected visual acuity (VA) and central macular thickness (CMT; central 1 mm subfield thickness) from optical coherence tomography (OCT) was analysed over the follow-up period. Genetic analysis for mutations in the retinoschisis gene (RS1) was also performed. Results: The age of patients at the start of treatment was 18 and 20 years, and follow-up duration was 6 months. In patient 1 CMT at the final follow-up was significantly better than at baseline (RE 563 vs 430 μm, LE 501 vs 277 μm), as well as VA (RE 3/10 (0,522 logMAR) LE 3/10 (0,522 logMAR).vs RE 6/10 (0,221 logMAR), LE 5/10 (0,301 logMAR) ); in patient 2 CMT at the final follow-up was also better than at baseline (RE 496 vs 416 μm, LE 519 vs 455 μm), hoever VA remained unchanged (RE 4/10 (0,397 logMAR) and LE 5/10 (0,301 logMAR)). Oral acetazolamide administered for three months achieved a substantial reduction of macular cysts and, to a lesser extent, of visual acuity, with no adverse effects. The topical 2% dorzolamide did not obtain a further reduction of CMT and the visual acuity was unchanged. Sequence analysis of the RS1 gene identified a hemizygous 589C>T (Arg197Cys) missense mutation in exon 6. The patients' mother was heterozygous 589C/T and also an unaffected sister was heterozygous for this mutation. This mutation has not been previously reported in Italian families with XLRS. Conclusions: This study showed that both oral acetazolamide and topical dorzolamide have effect in reducing or stabilize central macular thickness and improve or stabilize VA in 2 patients with XLRS maculopathy associated with a hemizygous 589C>T (Arg197Cys) missense mutation in exon 6. Given the potential requirement for long term treatment, the utility of acetazolamide may be limited by potential systemic side effects, while a topical medication would be preferable for long term treatment.