A clinical trial of MK-507, Trusopt, for raised intraocular pressure--the Australian experience.

Author(s): Gillies WE, Brooks AM

Affiliation(s): Clinic 3, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria.

Publication date & source: 1996-05, Aust N Z J Ophthalmol., 24(2):111-5.

Publication type: Clinical Trial; Multicenter Study; Randomized Controlled Trial

BACKGROUND: Since the introduction of carbonic anhydrase inhibitors, a topical preparation has been sought to avoid the complications of systemic medication while retaining the effect of lowering intraocular pressure. Recently, a topical carbonic anhydrase inhibitor, MK-507, has been found superior to others and introduced for multicentre clinical trial. PATIENTS AND METHODS: As part of an international multicentre trial, we compared MK-507 with beta blockers for one year in 20 patients with raised intraocular pressure, both as monotherapy and in combination. RESULTS: Twelve patients with a mean peak pressure of 31.9 +/- 6.8 mmHg (range, 22 to 49 mmHg) off all medication received MK-507. After two weeks, mean peak pressure was 24.7 +/- 6.1 mmHg (range, 14 to 41 mmHg)--a 22.6% fall in pressure. Six of these patients had a mean peak pressure of 27.8 +/- 6.4 mmHg (range, 21 to 41 mmHg), a fall of 19.2% from day one and were given timolol as add-on therapy. This resulted in a fall to 19.1 +/- 2.8 (range, 15 to 24 mmHg) at year one, a fall of 31.3% after add-on. Four patients on timolol and four on betaxolol gave similar falls in pressure with an additional fall when MK-507 was used as add-on therapy. CONCLUSIONS: MK-507 demonstrated its effectiveness as an ocular hypotensive agent in this trial of patients with an unusually high rise in pressure. It showed a hypotensive effect roughly equivalent to beta blockers. It is likely that either a topical carbonic anhydrase inhibitor or a cardioselective beta blocker will be the medication of first choice in newly diagnosed glaucoma.