Quantitative analysis of choroidal and retinal thickness and blood flow in a rat model of lens-induced myopia using OCTA.

PURPOSE: The aim of this study was to use optical coherence tomography angiography (OCTA) to quantitatively analyze the changes in the thickness of the choroidal and retinal layers as well as the alterations in intraretinal blood flow in lens-induced myopia (LIM) rats, and to provide a basis for mechanistic studies of myopia models from the perspective of the choroid and the retina. METHODS: We conducted LIM modeling in rats and set up a normal control (NC). After 8 weeks of modeling, use a high-resolution anterior and posterior segment biometric OCTA to measure the axial length, choroidal thickness, and the thickness of the inner, outer, and entire retinal layers in two groups of rats, and quantify changes in blood flow in the inner layer of the retina. The results were analyzed using t-test. RESULTS: Compared with NC, LIM rats had longer axis, thinner choroid thickness, thinner inner, outer and whole retinal thickness, and lower blood flow density in inner retina. The differences were statistically significant at most measurement points. CONCLUSIONS: OCTA revealed three myopia hallmarks: axial elongation, choroidal/retinal thinning, and retinal hypoperfusion. These findings enhance clinical understanding of myopic morphological changes and provide mechanistic insights into choroidal-retinal contributions. OCTA's noninvasive high-resolution enables longitudinal monitoring of ocular structural/vascular changes, offering a basis for diagnosing and preventing high-myopia retinopathy. TRANSLATIONAL RELEVANCE: This study used OCTA to non-invasively quantify retinal and choroidal structure and blood flow abnormalities in a myopia animal model, providing translatable imaging biomarkers for the early clinical screening of retinal lesions associated with high myopia.