The Effect of Topical Ocular Hypotensive Agents on Ocular Perfusion as measured by OCT Angiography

Abstract

Purpose : To determine whether there is a change in peripapillary retinal or macular perfusion after instilling glaucoma eye drops in healthy participants.

Methods : Healthy participants were recruited to this prospective, randomized trial. OCT angiography of the macula and peripapillary retina was performed to obtain the macular superficial vascular complex (SVC) vessel density (VD) and peripapillary nerve fiber layer plexus (NFLP) capillary density (CD). A 70 kHz, 840 nm wavelength OCTA system (AngioVue, Optovue, Inc) was used. At the baseline visit, a medical history was taken and dilated eye examination and imaging were performed. At the second and third visits, the participants were imaged in both eyes before and 2 hours after receiving either timolol or latanoprost eye drop in the right eye. The order of the 2 drops was randomized and the visits were separated by 5 weeks. Paired t-tests were used to evaluate the IOP and perfusion changes.

Results : The study included 18 eyes of 9 normal participants. The average IOP in the right eye changed from 12.8 ± 2.4 to 10.5 ± 1.9 (p = 0.008) with timolol and from 12.7 ± 2.7 to 10.3 ± 3.4 (p =0.005) with latanoprost. In the control left eye, there was no change in IOP (14.0 ± 2.2 to 13.8 ± 3.0 (p = 1.0)). With timolol treatment, the NFLP CD changed from 68.3 ± 5.2% to 69.6 ± 4.5% (p = 0.286); the SVC VD changed from 53.1 ± 6.1% to 54.1 ± 5.4% (p = 0.400). With latanoprost treatment, the NFLP CD changed from 70.3 ± 5.4% to 71.3 ± 5.6% (p = 0.420); the SVC VD changed from 54.3 ± 5.7% to 55.7 ± 5.8% (p = 0.310). The reproducibility for NFLP CD was 2.5% (pooled standard deviation) and for SVC VD was 1.8%. The sample size of 9 had 80% power to detect a change of 2.4% in NFLP CD and 1.7% in SVC VD at a significance level of p<0.05.

Conclusions : Timolol or latanoprost had little short-term effect on vessel density in healthy normotensive subjects as measured by OCTA.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.