Protective roles of ketamine and xylazine against light-induced retinal degeneration in rats

Purpose: To study the protective effects of ketamine and xylazine against light exposure-induced retinal degeneration (RD) in rats. Methods: Sprague Dawley rats were divided into three groups viz: light damage before anesthesia (LAE), light damage only (LDO), and control (CON) group which was kept in the dark for 12 - 18 h to habituate before light exposure. LDO group was exposed to light before anesthesia, while LAE group was maintained under anesthesia with ketamine and xylazine. The groups were kept for 120 min in darkness after anesthesia prior to light exposure and they were awakened prior to light damage. Functional assessment was carried out using electroretinography while morphological analysis was carried out using histology and immunochemistry techniques. Results: Ketamine-xylazine combination preserved the function of the retina and protected against light-induced RD based on retinal imaging studies and immunochemistry analysis. Xylazine and ketamine anesthesia provided protection against light-induced retinal damage, and thus reduced photoreceptor cell death. Conclusion: These results indicate that xylazine and ketamine anesthesia offer protection against light-induced damage and photoreceptor cell death in rats, and therefore, can potentially be developed for use in humans.