Treatment of Cystoid Macular Edema in Patients With Retinal Degeneration

A percentage of patients with retinal degeneration, a group of progressive blinding diseases, are known to develop fluid within the center part of their retina known as macular edema. Previous studies have documented that an oral form of carbonic anhydrase inhibitor (acetazolamide) can be effective in reducing the amount of macular edema in such patients (Archives of Ophthalmology, 106:1190-1195, 1988; 107:1445-1452, 1989). However, the use of the oral form of this medication is known to cause clinically significant side effects such as fatigue and loss of appetite.

A topical form of carbonic anhydrase inhibitor, (Trusopt) has promise for having a similar beneficial effect on the retinal fluid while not having the systemic side effects observed with the oral form of medication.

In the current study, we propose to use topical Trusopt in a group of patients with retinal degeneration (RD) to determine its efficacy in reducing the amount of retinal fluid in patients with RD and macular edema. The methods will involve an initial one month treatment with topical Trusopt three times a day in each eye. After a period of one month, patients will return for a follow-up examination. At baseline, they will have had a measurement of their center vision and a measurement of their macular fluid with a photographic-like procedure termed optical coherence tomography (OCT). After the one month period of treatment, they will again have a measurement of their vision and re-evaluation with OCT. An improvement of one line or more of vision will be considered as a significant improvement. Since the short-term intervisit variability in the area of macular edema in patients with RD can vary from 11% to 16%, a reduction in fluid of at least 25% in area will be considered as a clinically significant improvement of macular edema.