Quantitative measurement of laser-induced choroidal neovascularization with spectral-domain optical coherent tomography / 中华实验眼科杂志

ABSTRACT

Background The neovascular form of the disease usually causes severe vision loss in a number of eye diseases.Special-domain optical coherence tomography (SD-OCT) provides high-quality in retinal imaging and the possibility of the measurement in vivo.Objective 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 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,CNV memberane thickness (CMT) 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(both P＜0.05).CMT 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 21 days was significantly declined in comparison with 7 days(both P＜0.05).The results of SD-OCT showed a consistent 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 CNV in vivo.