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

In patients with normal-tension glaucoma, 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. Topical anti-glaucoma medications may improve ocular perfusion pressure or micro-circulation in the optic nerve head. The study evaluated the responses of the retinal vessel density (VD) to topical carteolol, brimonidine, and dorzolamide in normal-tension glaucoma (NTG) using optical coherence tomography angiography (OCTA). This is a retrospective non-randomized, comparative study. The study included 131 individuals (77 men, 54 women) diagnosed with NTG, without systemic medication usage, 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 OCTA parameters and retinal nerve fiber layer (RNFL) thickness to drugs, six months after treatment. 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 paripapillary area of the carteolol-treated eyes. Finally, in brimonidine-treated eyes, changes in either VD parameters or RNFL thickness were not significant. 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, the peripapillary microcirculation remained unchanged. The study shows preliminary results, future large-scaled studies are warranted to confirm the findings.