Abstract
Purpose :
X-Linked Retinoschisis (XLRS) is the most frequent inherited macular dystrophy among young males, characterized by the presence of cystic lesions in the macular region. Until now no treatment is available for XLRS. We performed a clinical evaluation of the effects of oral carbonic anhydrase inhibitors (CAI) in patients with XLRS.
Methods :
Twelve patients (aged 31.0 ± 13.6 years; range: 7 – 49 years) with a clinical and genetic diagnosis of XLRS and macular schisis in both eyes were enrolled in the study; they were treated with oral CAI (dose ranging 250-500 mg/day according to age) for a period of 6 months, and underwent a comprehensive ophthalmological examination at baseline, and 6 months after the beginning of the therapy, including best corrected visual acuity (BCVA) with ETRDS charts, spectral domain optical coherence tomography (OCT) and microperimetry (MP1).
Paired t-tests were used to compare baseline and 6-month values and were done independently for right (RE) and left (LE) eyes. The study was carried out in compliance with the Declaration of Helsinki.
Results :
After six months of treatment, no significant change (p>0.05) in BCVA was observed (baseline RE: 0.34 ± 0.31; LE: 0.30 ± 0.21; 6-month RE: 0.35 ± 0.32; LE: 0.35 ± 0.21). However, we observed an improvement of macular schisis and a decrease (>30 μm) in central macular thickness (CMT) in 15 eyes (62.5%). On average, CMT significantly (p<0.05) decreased from 372 ± 185 μm to 269 ± 162 μm in RE and from 384 ± 176 μm to 265 ± 138 μm in LE. Moreover, MP1 showed an improvement of mean macular sensitivity (MS) in 16 eyes (66.7%). In particular, MS significantly (p<0.05) increased from 10.2 ± 6.4 dB to 14.4 ± 6.3 dB in RE, from 10.8 ± 6.4 dB to 14.2 ± 5.6 dB in LE. No significant (p>0.05) change in fixation stability parameters was assessed. Finally, we observed that in 11 eyes (45.8%) the CMT improvement was associated with increased MS.
Conclusions :
Our study suggests that oral CAI is efficacious not only in recovering normal retinal anatomy (i.e., reabsorbing macular cystic lesions) but also in improving MS in XLRS patients. The recovery of normal retinal anatomy by oral CAI could also be useful to maximize the effect of surgical therapeutic treatments for XLRS, such as gene therapy, now under evaluation in clinical trials.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.