Instrumental and morphological assessment of changes in the mouse corneal stroma in the dynamics of post-traumatic recovery

Relevance. Around the world, corneal blindness caused by impaired transparency is one of the leading causes of vision loss. Damage to the cornea can also lead to the development of opacities. The pathogenesis of corneal opacities is based on pathomorphological changes in the corneal stroma. To explore the therapeutic potential of biomedical products and develop new treatments, a standardized and reproducible in vivomodel of corneal stromal injury is needed. In experimental ophthalmology, mouse models of various corneal injuries are widely used, but the dynamics of posttraumatic restoration of the ultrastructural organization of the stroma have been little studied. Purpose. To evaluate structural and functional changes in the corneal stroma of mice in the dynamics of post-traumatic recovery. Material and methods. Injury to the corneal stroma was performed using a sharp 33G needle in the form of a tunnel defect in the thickness of the cornea of C57BL/6 mice. The presence of post-traumatic damage and the dynamics of corneal recovery were assessed using instrumental methods (biomicroscopy of the anterior segment of the eye with a fluorescein test, optical coherence tomography (OCT) before, immediately after the injury, and after 2 and 4 weeks after injury. Transmission electron microscopy was performed using a JEM 1400 electron microscope. Morphometry of digital images was performed using Image J software, calculating the minimum nearest interfibrillar distance, diameter and fibril density. Results. The formation of a corneal stromal wound was confirmed by the development of reactive edema according to OCT data and the accumulation of fluorescein in all damaged corneas. 2 weeks after the injury, complete epithelization of the wound surface was observed. According to OCT data, 2 weeks after the injury, an increase in corneal thickness by 34% and an increase in the opacity index by 1.5 times were recorded compared to a healthy cornea. By the 4th week of observation, the corneal thickness and opacity index remained at a high level in the injured cornea. After the formation of injury to the corneal stroma, a decrease in the diameter of collagen fibrils, an increase in fibril density and the shortest nearest interfibrillar distance were revealed throughout the observation period. onclusion. A mechanical model of corneal trauma performed using a sharp 33-gauge needle induces the formation of stable stromal opacities. Instrumental and morphological research methods did not reveal stromal restoration during the entire observation period (4 weeks). Key words: corneal trauma, optical coherence tomography, corneal thickness, corneal transparency, corneal morphology, corneal fibrils