Abstract
Purpose: :
X-linked juvenile retinoschisis (XLRS) is an X-linked bilateral vitreoretinal dystrophy, characterized by areas of macular schisis or splitting of the neural layers of the retina resulting in cystic cavities. The condition affects from 1:5000 to 1:25000. Typically, visual acuity of affected males ranges from 20/60 to 20/120. XLRS results from defective or absent retinoschisin, a cell-adhesion and cell-cell interaction protein secreted by retinal neurons. Currently, there are no highly effective medical or surgical treatments for the condition. The purpose of this case report is to document the use of a carbonic anyhydrase inhibitor as a medical treatment modality and describe its efficacy in restoring retinal anatomy and function.
Methods: :
Dorzolamide (a carbonic anyhydrase inhibitor) 2% eye drops twice daily were prescribed to a patient with XLRS. Spectral-domain optical coherence tomography (OCT) (Spectralis) and multifocal electroretinogram (mfERG) were used to assess retinal anatomy pre- and post-treatment. mfERG responses from both eyes were recorded according to ISCEV standards.
Results: :
We report the case of a 31 year old male with a family history of retinoschisis. Fundus examination showed foveal stellate cystic changes OU and an infero-temporal region of retinoschisis OD. Pinhole corrected vision to 20/80 OU. OCT revealed schisis cavities and cystoid changes in the retina in both eyes. Dorzolamide drops were initiated in both eyes. Two months post-treatment, the OCT of the both eyes showed central flattening in the retina. Six months post-treatment pinhole had improved to 20/60-2 OD and 20/70-1 OS. The patient noted subjectively "brighter vision and a wider field" after dorzolamide treatment. mfERG amplitudes and latencies also improved over five months of treatment. On average, mfERG amplitudes increased 248.6%, 5.8%, and 53.6% in rings 1, 2, and 3, respectively. On average, mfERG latencies became faster by 24.8%, 1.4%, and 3.5%, respectively.
Conclusions: :
A measurable degree of flattening of the central retinoschisis was seen on OCT after two months of dorzolamide treatment. Vision improved from 20/80 OU pinhole to 20/60-2 OD and 20/70-1 OS pinhole. mfERG responses also improved after five months of treatment. There have been several previous reports of dorzolamide flattening schisis cavities in XLRS. This report is the first to describe an improvement in the mfERG after the use of dorzolamide in XLRS.
Keywords: retinal degenerations: hereditary • degenerations/dystrophies • carbonic anhydrase