【Animal Modeling】-Experimental study on the model of choroidal neovascularization induced by different power 532nm lasers in brown Norwegian rats

  Objective To use different powers of 532nm laser to induce choroidal neovascularization model in brown Norwegian rats, in order to explore the laser power with the highest modeling rate.

  Methods Forty-five Norwegian brown rats were randomly divided into 3 experimental groups, 15 rats in each group, the laser power was 400mW, 300mW, 200mW, the spot diameter was 100 μm, the exposure time was 100ms, and 10-12 spots were photocoagulated in each eye. Color fundus photography, fluorescein angiography and optical coherence tomography were performed on the 1st week, 2nd week, 3rd week and 4th week after laser modeling in each experimental group, and the experimental data were counted.

  Results The retina after laser induction showed edema due to the destruction of the vitreous membrane in the color fundus photo. Fluorescein angiography showed that the leakage rate of the laser with a power of 200mW, 300mW and 400mW was compared in the 1-4th week after induction, and the difference was statistically significant. (P<0.05); 300="" the="" power="" was="" p="">0.05), the leakage rate was statistically significant in the 2nd and 4th weeks (P<0.05); the="" laser-induced="" leakage="" in="" 1st="" and="" 2nd="" weeks="" with="" a="" power="" of="" 200mw="" there="" was="" no="" significant="" difference="" rate="" p="">0.05), but there was a statistically significant difference in the leakage rate between the 1st, 3rd week and the 2nd and 3rd week (P<0.05). There was a statistically significant difference in the leakage rate between the 2nd and 3rd weeks (P<0.05), and="" there="" was="" no="" significant="" difference="" in="" the="" leakage="" rate="" between="" three="" groups="" 3rd="" 4th="" week="" p="">0.05). Optical coherence tomography showed that the retinal destruction results in disorder, and then induces choroidal neovascularization, which eventually tends to stabilize, with some retinal structures shrinking and thinning.

  Conclusion 200mW, 300mW, 400mW 532nm laser can induce the formation of choroidal neovascularization model in Norwegian brown rats, and 300mW has the highest modeling rate, choroidal neovascularization begins to form after 1 week, reaches the peak in the 3rd week, and reaches the peak in the 4th week. becoming steady.