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

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 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 % 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 χ2 = 30.04, P < 0.0001). Mortality risk was 30.72 times higher in the traditional group (95 % CI: 13.41-70.36). Additionally, pups in the modified group exhibited greater weight gain (P = 0.002) and increased pathological retinal neovascularization (11.39 % vs. 2.60 %; P = 0.0001). However, there was no significant difference in the avascular area between groups (modified: 25.71 % [IQR: 11.86 %] vs. traditional: 23.10 % [IQR: 12.13 %], P = 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.