Timolol/dorzolamide combination therapy as initial treatment for intraocular pressure over 30 mm Hg

PURPOSE: To determine the intraocular pressure (IOP)-lowering effect of a fixed timolol/dorzolamide combination (Cosopt) for patients with IOP over 30 mm Hg. STUDY DESIGN: Prospective interventional case series. METHODS: Eighteen patients being seen on the Wills Eye Hospital Glaucoma Service with at least one eye with an IOP > 30 mm Hg were recruited. None had used any glaucoma medications for at least 1 month. IOP was confirmed by diurnal testing. Cosopt was administered at 9 am and 9 pm. Trough IOP measurements were made at 9 am and peak IOP measurements at 11 am at baseline, 1 month, and 2 months. Pretreatment and posttreatment IOPs were compared using a paired-samples independent t test. RESULTS: Mean pretreatment IOP was 37.5 +/- 1.0 mm Hg. Baseline posttreatment IOP was 18.4 +/- 0.5 mm Hg (P < 0.01). At 2 months, the mean trough IOP was 21.1 +/- 0.9 mm Hg and the peak, 17.6 +/- 0.6 mm Hg (each, P < 0.01, as compared with pretreatment baseline IOP). One patient did not respond to Cosopt; two had a clinically insufficient response and did not complete the study. Data from these patients were included in the analysis. CONCLUSIONS: Over 80% of the eyes responded to Cosopt, with an average trough IOP reduction of 40% at 2 months.