Introduction: Yag laser iridotomy is frequently associated with an
increase of intraocular pressure (IOP), that is particularly alarming in
glaucoma patients. The aim of the present study was to evaluate the efficacy of
dorzolamide 2%, a topical carbonic anhydrase inhibitor, in controlling IOP peak
after laser iridotomy. Methods: 42 patients with angle-closure glaucoma were
randomly divided in two groups and treated in one eye with dorzolamide 2% or
placebo eye-drop one hour before and immediately after Yag laser iridotomy. IOP
was recorded before the topical treatment and 1, 3 and 24 hours after the laser
procedure. The study was double-masked. Results: In the placebo treated group
(21 patients) we observed an increase of IOP>5 mmHg in 10 patients after 1
and 3 hours from the laser treatment and in 6 patients after 24 hours. In the
other group (21 patients), treatment with dorzolamide prevented the IOP spike
induced by laser treatment. In fact, in only one case we observed an increase
of IOP>5 mmHg after iridotomy. Conclusions: Our data confirms the high
frequency of IOP increase after Yag laser iridotomy, thus suggesting the use of
a prophylactic treatment. Dorzolamide 2% appears to be an effective drug, with
a safe systemic profile.