The additive effect of topical dorzolamide and systemic acetazolamide in pediatric glaucoma

BACKGROUND The effect of adding oral to topical carbonic anhydrase inhibitors in the management of pediatric glaucoma is unknown. METHODS We undertook a retrospective analysis of children with a diagnosis of glaucoma before the age of 16 years who initially were treated with topical dorzolamide or dorzolamide-timolol combination and then treated with oral acetazolamide. Children who had uveitic glaucoma or who had ocular surgery within 3 months before or during oral acetazolamide therapy were excluded. Various methods of intraocular pressure (TOP) measurement were used in the study. However, in each case, the TOP was measured using the same technique, once at the last visit before the addition of oral acetazolamide and once at the first examination after the addition of oral acetazolamide. RESULTS Twenty-two patients were included in the study with an age range of 8 months to 15 years. Seventeen children were boys. Oral acetazolamide treatment was via a daily dose (13.3 to 30 mg/kg, mean 22.5 mg/kg), and duration (6 to 31 days, mean 18.1 days). The intraocular pressure (mean +/- SD) before acetazolamide (32.2 +/- 6.5 mm Hg) was significantly different than after acetazolamide (21.8 +/- 6.3 mm Hg) with a mean difference of 10.36 mm Hg (p < 0.0001) and a mean decrease in TOP of 29.6%. CONCLUSIONS The addition of oral acetazolamide to topical dorzolamide may provide additional reduction in TOP in some children already being treated with topical carbonic anhydrase inhibitors. This possible additive effect has not been observed in adults treated with a combination of topical and systemic carbonic anhydrase inhibitors.