Résumé
Objective Choroidal neovascularization(CNV) is the main cause of blindness in over 50-years-old population. To establish an available CNV animal model is helpful for us to understand the pathogenesis and management of CNV. Purpose of present study was to observe the role of coagulation with different power of diode laser in laser-induced choroidal neovascularization model of Brown Norway (BN) rats. Methods Coagulation of 810 nm diode laser(8 - 10 spots for each eye) was performed in 36 male BN rats with the spot diameter 75 μm, shutter time 0. 1 s, power 120 mW, 140 mW and 160 mW, respectively, while 6 normal BN rats were used as contrast. CNV was evaluated by fundus examination, fundus fluorescein angiography (FFA), indocyanine green angiography(ICGA) and light microscope on day 1, 7, 14, 21, 28 and 56 after photocoagulation. Results CNV formed on the 7th day after photocoagulation in 120 mW, 140 mW and 160 mW groups and reached the peak on the 21st day according to FFA and ICGA manifestation. Incidence of CNV in 120 mW, 140 mW and 160 mW group was 51. 3%, 91. 8%, 88. 3% on FFA findings and 51.3%, 92.7%, 93.7% on ICGA findings, respectively. In 7 days after photocoagulation, inflammatory cells increased and CNV formed at the lesion. Photocoagulation plaque became thicker with pigment cells proliferating and migrating on 14 days. After that time, inflammatory cells decreased and more collagen fibers emerged. The CNV reminded till the 56th day after photocoagulation. Conclusion CNV model of BN rats can be successfully created using the different power of diode laser (from 120 through 160 mW). CNV rate under the laser coagulation with 140 mW is higher, indicating that the power of 140 mW may be a suitable parameter for diode laser-induced choroidal neovascularization model of BN rats.