Ga. Fishman et al., REBOUND OF MACULAR EDEMA WITH CONTINUED USE OF METHAZOLAMIDE IN PATIENTS WITH RETINITIS-PIGMENTOSA, Archives of ophthalmology, 111(12), 1993, pp. 1640-1646
Purpose: To assess the effect of methazolamide on chronic macular edem
a in patients with retinitis pigmentosa in a double-masked, placebo-co
ntrolled, crossover study. Three subjects who had an initial improveme
nt in their macular edema as demonstrated on fluorescein angiography r
eceived a continued course of methazolamide to assess its effect on ma
cular edema. Methods: Seventeen subjects were enrolled in the initial
study. On angiography, nine subjects demonstrated improvement in their
macular edema with the use of methazolamide for 3 weeks; three of the
se continued receiving the drug at a dosage of 50 mg twice daily for e
ither an additional 6 (one subject) or 12 (two subjects) weeks. All su
bjects were assessed at each visit with fluorescein angiog raphy and o
n best corrected visual acuity, both undilated and dilated; a subjecti
ve impression was also documented. Results: After 6 and 12 weeks of tr
eatment, all three subjects experienced a rebound of angiographic macu
lar edema to some extent. The visual acuity varied only slightly (up t
o 7 letters) from both the baseline and most recent examinations after
6 and 12 weeks of treatment. Conclusion: Results from these few subje
cts suggest that at least a partial rebound of macular edema seen angi
ographically may occur with the continued use of methazolamide in pati
ents with retinitis pigmentosa and chronic macular edema. Further stud
y is required to determine if this rebound effect also occurs in treat
ment of other ocular disorders with chronic macular edema.