Bunazosin inhibited axial elongation with an increase of the choroidal blood perfusion in a murine model of myopia

ABSTRACT

Purpose: The prevalence of myopia is accelerating worldwide possibly because of the decrease in outdoor activity including COVID-19 home confinement. We have reported the effective treatments of suppressing myopia progression, including oral administration of crocetin (Mori K et al. Sci Rep. 2019) and violet light exposure (Jiang X et al. Proc Natl Acad Sci USA. 2021). In this study, we examined the therapeutic effects of bunazosin, known as one of the α1-adrenergic receptor antagonists, in a lens-induced myopia mouse model. Methods: C57BL/6J mice were induced myopia at 3-week-old by a method established in our research group (Jiang X et al. Sci Rep. 2018). For 3 weeks, mice were equipped with lenses in both eyes, a left for 0 D lens as internal control and a right for -30 D lens as myopia induction. During this period, we administered 0.01% bunazosin hydrochloride solution by intraperitoneal injection (IP group) and eye drop (E group) once a day, and PBS as control. Ocular components including refraction error, axial length, and choroidal thickness before and after myopia induction were measured by an infrared photorefractor and an SD-OCT. The choroidal blood flow was evaluated by an SS-OCT angiography. Results: In the eye with -30D lens of control group, significant changes in a myopic shift of refraction (p < 0.01), axial elongation (p < 0.05), and choroidal thinning (p < 0.01) compared to 0D lens were observed. In contrast, IP or E groups showed no significant difference between both eyes, suggesting myopia progression was suppressed by bunazosin treatment. The choroidal blood flow of the eye with -30D in E group (58.9±8.9%) was higher than that of the control group -30D (44.0±6.4%)(p < 0.05). Conclusions: Bunazosin has a preventive effect on myopia progression by suppressing axial elongation and choroidal thinning together with an increase of choroidal blood flow.