Abstract
Purpose:
This study aimed to investigate the feasibility of SD-OCT dynamically measuring choroidal neovascularization (CNV).
Methods:
CNV was induced in 30 left eyes of 30 clean Brown Norway (BN) rats by retinal photocoagulation with 532 nm laser with the laser parameter as follows: wavelength 532 nm, exciting power 200 mW, spot diameter 100 μm and irradiating time 50 ms. Bubble or less retinal bleeding was thought as Brunch membrane breakage and CNV model establishment. Fundus fluorescein angiography(FFA) was performed to determine the establishment of CNV model and scored based on the fluorescein leakage on 3, 7, 14, 21 days after photocoagulation. Meanwhile, thickness of CNV was dynamically measured in vivo as the maxiume value from retinal inner limiting membrane through choroidal vessel layer in various time points. Histopathologic examination was used in the 14th day to evaluate and verify the result of SD-OCT. The right eyes were as controls.
Results:
FFA examination showed that disc-like leakage of fluorescein appeared in 7 days and extended in 14 days after photocoagulation with the scores of 1.6±0.4, 2.5±0.6 and 2.4±0.5 in 7, 14 and 21 days, showing a significant difference among them (F=13.11, P<0.01). The fluorescein leakage score was significantly higher in 14 and 21 days than that of 7 days (P<0.01). CNV thickness measured by SD-OCT was (76.33±10.09), (102.03±14.21) and (98.03±13.76) μm in 7, 14 and 21 days after photocoagulation respectively, with a significant difference among 3 time points (F=23.25, P<0.01), and that in 14 and 21days was significantly declined in comparison with 7 days (P<0.01). The results of SD-OCT showed a consist tendency with that of FFA. Histopathological examination showed CNV formation in 14 days after photocoagulation.
Conclusions:
Experimental CNV model was successfully induced by laser photography. SD-OCT technology allows excellent visualization of rat CNV in vivo.
Keywords: 609 neovascularization