INCREASE OF RETINAL VESSEL WIDTH IN OCULAR HYPERTENSIVES WITH TIMOLOLTHERAPY

Purpose: The purpose of this study was to determine whether timolol dr ops compared to placebo drops had a significant effect on retinal vess el width in ocular hypertensives. Methods: Thirty-seven ocular hyperte nsives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. M easurements of ocular pressure and retinal vessel width by computerize d image analysis from fundus photographs were made at about 3 month in tervals for 18 to 24 months of follow-up. Results: None of the subject s developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals, Subjects treated w ith the placebo showed no change in ocular pressure and a significant decrease in retinal vessel width over time especially in the right eye . Subjects treated with timolol had an increase in retinal vessel widt h compared to the placebo group significant especially for the superio r temporal vein. Multivariate analyses indicated that the increase of retinal vessel width was not associated mainly with the ocular pressur e on treatment or decrease in ocular pressure on treatment. Conclusion : Timolol treatment was associated with an increase of retinal vessel width. The effect of timolol appears to be related primarily to mechan isms other than the decrease in ocular pressure.