Enhanced acute ocular hypotensive response to timolol with dexamethasone treatment

This study was conducted to determine whether low doses of dexamethasone can enhance the lowering of ocular pressure by low doses of timolol.

In 12 patients with untreated ocular hypertension and similar intraocular pressures in each eye, one eye was randomly selected in a masked manner for pretreatment with three applications of topical 0.01% dexamethasone sodium phosphate drops prepared in artificial tears. The other eye was treated with three applications of drops of artificial tears alone. Both eyes were then treated with 0.01% timolol maleate drops. Ocular pressure was measured for the next 100 minutes at 20-minute intervals. The study was done in an outpatient office. Twelve untreated ocular hypertensive patients participated in this study.

When compared with eyes treated with timolol drops alone, eyes pretreated with dexamethasone drops showed a significantly greater decrease in ocular pressure (mean +/- SD); the maximal decrease in 12 dexamethasone-treated patients was 3.5 +/- 1.9 mm Hg (15.9% from baseline). Six dexamethasone-treated patients had a response of 4.0 to 6.0 mm Hg, whereas three showed responses < 4 and > 2 mm Hg with three < or = 2 mm Hg.

This synergistic effect of timolol with dexamethasone on lowering of ocular pressure offers a potential therapeutic use in ocular hypertension and glaucoma.