Short-Term Effects of Different Types of Anti-Glaucoma Eyedrop on the Sclero-Conjunctival Vasculature Assessed Using Anterior Segment OCTA in Normal Human Eyes: A Pilot Study

• Main Authors: Tadamichi Akagi, Yoko Okamoto, Takanori Kameda, Kenji Suda, Hideo Nakanishi, Masahiro Miyake, Hanako Ohashi Ikeda, Tatsuya Yamada, Shin Kadomoto, Akihito Uji, Akitaka Tsujikawa
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Journal of Clinical Medicine
• Subjects: Anterior segment optical coherence tomography angiography; anti-glaucoma eyedrop; aqueous humor outflow pathway; intraocular pressure reduction
• Online Access: https://www.mdpi.com/2077-0383/9/12/4016

Background: To investigate the short-term effects of different types of anti-glaucoma eyedrop on sclero-conjunctival vasculatures and their associations with intraocular pressure (IOP) reduction. Methods: This was a prospective study including 20 healthy subjects. A single instillation of ripasudil or bimatoprost was introduced into the right eyes of the participants. The superficial (conjunctival) and deep (intrascleral) vasculatures of the corneal limbus using anterior-segment optical coherence tomography angiography (OCTA) and IOP were examined in both eyes at baseline and 15 min and 2 h after instillation. Results: In the ripasudil group, the vessel density (VD) (median) at baseline (deep, 13.1%; superficial, 28.5%) significantly increased in both layers at 15 min (deep, 19.9%; superficial, 37.3%) and the deep layer at 2 h (deep, 14.8%; superficial, 31.6%). In the bimatoprost group, the superficial VD significantly changed over time, but the deep VD did not. The greater effect of ripasudil on IOP reduction was significantly associated with a lower baseline VD in the deep layer (at 15 min, <i>p </i>=<i> </i>0.004; at 2 h, <i>p </i>= 0.018). Conclusions: Differences in the timing, depth, and extent of the effects on vasculature after instillations, could be detected using OCTA. The IOP-lowering effects of ripasudil might be associated with the deep vasculature.