Author contribution: Bikbov ММ — study concept and design, advising, editing; Israfilova GZ, Gilmanshin TR — data acquisition and processing, manuscript writing and editing.

Compliance with ethical standards: the study was approved by the Ethics Committee of the Ufa Eye Research Institute and conducted in accordance with the fundamental ethical principles of the Declaration of Helsinki, GСP (Good Clinical Practice) principles, and current regulatory requirements; the informed consent was submitted by all study participants.