Optical Coherence Tomography Angiography Vessel Density Changes in Normal-tension Glaucoma Treated With Carteolol, Brimonidine, or Dorzolamide

Abstract

Precis: In patients with normal-tension glaucoma (NTG), topical dorzolamide might enhance the vessel density (VD), topical carteolol decreased the VD in the inferior-temporal peripapillary retina, whereas topical brimonidine did not change the VD.

Purpose: Topical antiglaucoma medications may improve ocular perfusion pressure or microcirculation in the optic nerve head. The study evaluated responses of retinal VD to topical carteolol, brimonidine, and dorzolamide in NTG using optical coherence tomography angiography.

Patients and methods: This is a retrospective, nonrandomized, comparative study. The study included 131 individuals (77 men, 54 women) diagnosed with NTG, without systemic medication use, who visited the glaucoma clinic of Chang Gung Memorial Hospital, Taiwan, between January 2019 and May 2020. If both eyes were diagnosed with NTG, only the right eye was included. Of these, there were 80 carteolol-treated eyes, 27 brimonidine-treated eyes, and 24 dorzolamide-treated eyes. We studied the response of optical coherence tomography angiography parameters and retinal nerve fiber layer (RNFL) thickness to drugs, 6 months after treatment.

Results: In dorzolamide-treated eyes, increases in the peripapillary superficial retinal VD, especially in the superior-nasal area, were significant; however, no RNFL thickness changes were observed. In contrast, the superficial retinal VD decreased at the inferior-temporal peripapillary area, and RNFL thickness decreased in the inferior-nasal peripapillary area of carteolol-treated eyes. Finally, in brimonidine-treated eyes, changes in either VD parameters or RNFL thickness were not significant.

Conclusions: Topical dorzolamide possibly enhanced the VD of the peripapillary retina in NTG eyes. On the contrary, topical carteolol possibly decreased VD in the inferior-temporal peripapillary retina. Finally, in cases treated with topical brimonidine, peripapillary microcirculation remained unchanged. The study shows preliminary results and future large-scale studies are needed to confirm findings.