Multimodal evaluation of 525 nm laser-induced retinal injury in rabbits: structural, functional and cytokine analyses

This study aimed to systematically study the characterize of retinal damage induced by 525 nm laser irradiation at different power densities through multimodal assessment methods, including structural, functional and cytokine analyses. A total of 24 rabbits were exposed to laser irradiation at 0.5, 200, 500, and 1000 mW/cm² with a single-eye exposure duration of 0.25 s. Multimodal evaluations including ERG, OCT/OCTA, histopathology and aqueous humor cytokine microarray analysis were used to evaluate the characteristics of laser-induced injury in rabbit eyes. No visible functional or pathological damage was observed after low-power laser radiation (0.5 mW/cm²). Laser irradiation exceeding 200 mW/cm² induced transient electroretinographic suppression and persistent laser spots in the fundus. Laser-induced retinal edema and hemorrhage were naturally absorbed within 7 days after injury, and cellular damage and structural changes persisted in the form of old plaques (14d). Notably, 1000 mW/cm² laser exposure caused severe retinal detachment (1d), ultimately leading to a retinal hole (14d). There was no significant difference in the inflammatory array clustering analysis of anterior aqueous humor, but several individual cytokines showed statistically significant differences: ANG-1 was upregulated (500 and 1000 mW/cm², p < 0.01) while VEGF-A was downregulated (500 mW/cm², p < 0.05); MIP-1β was significantly increased (200 mW/cm², p < 0.05), whereas IL-1RA was decreased (500 mW/cm², p < 0.05). The 525 nm laser induced dose-dependent retinal injury, ranging from reversible functional inhibition to irreversible structural damage, and triggered the expression of cytokines related to vascular stability and inflammation regulation.