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.

Comparative Assessment of Retinal Blood Flow Velocity Changes Following Brimonidine and Brinzolamide Administration Using Retinal Function Imaging

“… 31 More recent studies evaluated retinal perfusion after brimonidine application in patients with OHT and normal-tension glaucoma by OCTA, and found no evidence for a significant effect. 25 , 26 …”

The characteristics of fundus microvascular alterations in the course of glaucoma: a narrative review

“…Peripapillary blood flow increased after treatment with either brinzolamide (111) or dorzolamide/ timolol (115). OCTA results have further demonstrated a peripapillary region VD increase after the topical application of either dorzolamide (110) or latanoprost (112). Although brimonidine may not cause a significant change in the microvascular VD (110), it has been reported to be correlated with improved microvascular autoregulation (89,90).…”

“…However, some patients showed a decrease in the retinal blood flow after using topical carteolol ( 109 ). Lin et al used OCTA to detect a VD decrease in the inferior-temporal peripapillary region after topical carteolol use ( 110 ). Kurysheva observed a decrease in inside disc VD on OCTA after tafluprost administration ( 26 ).…”

Association of Intraocular Pressure and Optical Coherence Tomography Angiography Parameters in Early Glaucoma Treatment

“…However, the findings pertaining to the effect of IOP reduction on microvascular change in patients with glaucoma are inconsistent. Some studies have revealed an improvement in OCT angiography parameters after IOP reduction treatment [ 7 , 8 , 9 , 10 , 11 ], whereas others have not [ 12 , 13 , 14 ]. Moreover, most studies have focused on the effect of surgical IOP reduction [ 10 , 11 , 13 , 14 ] instead of medical IOP reduction [ 7 , 8 , 15 ], which is the most common initial choice for treating glaucoma.…”

“…Some studies have revealed an improvement in OCT angiography parameters after IOP reduction treatment [ 7 , 8 , 9 , 10 , 11 ], whereas others have not [ 12 , 13 , 14 ]. Moreover, most studies have focused on the effect of surgical IOP reduction [ 10 , 11 , 13 , 14 ] instead of medical IOP reduction [ 7 , 8 , 15 ], which is the most common initial choice for treating glaucoma. A prospective investigation of the changes in the ocular microvasculature induced by IOP-lowering medications may help to clarify the effect of long-term IOP reduction treatments on glaucoma.…”