Epidemiologic approach to open-angle glaucoma: 2. Survival analysis of adverse drug reactions. Report of the Canadian Ocular Adverse Drug Reaction Registry Program. The Collaborative Glaucoma Study Group.

Medical treatment, intraocular pressure (IOP) and adverse drug reactions were recorded in a prospective multicentre study of 71 unselected, newly diagnosed cases of open-angle glaucoma. Eight ophthalmologists recorded standard information at five visits over a mean interval of 12.1 months. No limitations were imposed on the choice of drugs or interval between visits. The IOP was satisfactorily controlled throughout the follow-up period with the first drug prescribed in 36% of eyes. In an additional 10% to 13% the IOP was stabilized with alternative therapy, prescribed for approximately one-third of eyes per visit. A total of 27 patients reported 18 severe and 31 mild suspected adverse reactions during the follow-up period. Survival analysis showed that there was no significant difference between the proportions of patients continuing treatment with the first, second and third drug prescribed (half-life of treatment approximately 210 days in all three cases). However, when only changes for unsatisfactory pressure were considered, the half-life of treatment was significantly longer, 350 days (p = 0.02).

Epidemiologic approach to open-angle glaucoma: 1. Control of intraocular pressure. Report of the Canadian Ocular Adverse Drug Reaction Registry Program.

In a multicentre study eight glaucoma consultants prospectively followed 71 unselected cases (130 eyes) of newly diagnosed open-angle glaucoma at five visits over a mean interval of 12.1 months. A standard flow chart was used to record the medical treatment, intraocular pressure (IOP) and indications for any changes in therapy. No limitations were imposed on the choice of drugs. The mean IOP before treatment was 28 mm Hg. There was a significant reduction in mean IOP of 7.64 mm Hg in response to the first drug prescribed (p less than 0.0001) but none thereafter, despite changes in treatment in 25% to 32% of eyes at each visit. The mean standard deviation of IOP for all eyes was 2.62 mm Hg. Of 99 changes in therapy in 67 eyes, 40% were made when the IOP was within 3 mm Hg of the mean satisfactory pressure for a particular case. The findings indicate the need to make corrections for variation and fluctuation in IOP when evaluating pressure response. The pharmacologic effect of the drugs appeared less important than the patient's ability to tolerate the drugs without severe adverse reactions.