Optimization of the oxygen-induced retinopathy model in mice and its impact on retinal angiogenesis.

Abstract

PURPOSE: To establish a simple, highly stable, and ethically compliant mouse model for in-depth investigation of oxygen-induced retinopathy. METHODS: C57BL/6J pups were subjected to the oxygen-induced retinopathy (OIR) model using either a modified protocol (with Kunming surrogate dams) or the traditional protocol (cross-fostering with C57 dams alternated every 12&#xa0;h). The effectiveness of the modified protocol was evaluated by comparing pup survival rates, weight changes, and the percentage of retinal neovascularization. RESULTS: The modified protocol significantly improved pup survival, with over 50&#xa0;% of animals surviving to the experimental endpoint at postnatal day 17 (P17). The median survival time for this group was not reached, far exceeding the traditional group's 7.00 days (Log-Rank &#x3c7;&#xa0;=&#xa0;30.04, P&#xa0;<&#xa0;0.0001). Mortality risk was 30.72 times higher in the traditional group (95&#xa0;% CI: 13.41-70.36). Additionally, pups in the modified group exhibited greater weight gain (P&#xa0;=&#xa0;0.002) and increased pathological retinal neovascularization (11.39&#xa0;% vs. 2.60&#xa0;%; P&#xa0;=&#xa0;0.0001). However, there was no significant difference in the avascular area between groups (modified: 25.71&#xa0;% [IQR: 11.86&#xa0;%] vs. traditional: 23.10&#xa0;% [IQR: 12.13&#xa0;%], P&#xa0;=&#xa0;0.165). CONCLUSION: The Kunming surrogate protocol significantly enhances the modeling efficiency and pup survival rate in oxygen-induced retinopathy (OIR), while concurrently reducing experimental animal consumption and costs.