Yazdani Negareh, Ehsaei Asieh, Hoseini-Yazdi Hosein, Shoeibi Nasser, Alonso-Caneiro David, Collins Michael J
Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran.
Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
Ophthalmic Physiol Opt. 2021 Nov;41(6):1308-1319. doi: 10.1111/opo.12875. Epub 2021 Sep 6.
To study regional variations in choroidal thickness (CT), luminal thickness and stromal thickness of the choroid, and choroidal vascularity index (CVI) in low myopic and emmetropic eyes using wide-field optical coherence tomography (OCT).
Sixty-nine healthy young adults between 20 and 38 years of age participated in this study, including 40 low myopes (mean ± SD spherical equivalent (MSE) refractive error: -3.00 ± 1.39 D, range: -6.00 to -0.62 D) and 29 emmetropes (MSE: -0.05 ± 0.09 D, range: -0.25 to +0.12 D). Wide-field CT, luminal thickness, stromal thickness and CVI were measured across five eccentricities (fovea, parafovea, perifovea; near-periphery and periphery) and four quadrants (nasal, temporal, inferior and superior), in vertical and horizontal meridians, while controlling for a range of extraneous factors potentially influencing the CT. Custom-written software was used to segment and binarize the OCT images.
Wide-field CT, luminal thickness and stromal thickness, averaged across all participants, exhibited significant topographical variation, with the foveal (379 ± 8 µm, 200 ± 4 µm, 179 ± 4 µm, respectively) and peripheral (275 ± 8 µm, 161 ± 4 µm, 114 ± 4 µm, respectively) regions presenting the thickest and thinnest regions (all p < 0.001). Wide-field CVI showed a progressively higher percentage (greater vascularity) with increasing eccentricity from the fovea towards the periphery (p < 0.001). Macular CT and stromal choroidal thickness were significantly thinner in myopes compared to emmetropes (p < 0.05). Myopes (55.7 ± 0.3%) showed a slightly higher CVI compared with emmetropes (54.4 ± 0.4%) (p < 0.05).
Low myopia in young adults was associated with significant choroidal thinning across the macular, but not extramacular regions, with this decrease in choroidal thickness mostly attributed to thinning in the stromal component of the choroid, rather than the luminal (vascular) component.
使用广角光学相干断层扫描（OCT）研究低度近视和正视眼脉络膜厚度（CT）、脉络膜管腔厚度和基质厚度以及脉络膜血管指数（CVI）的区域差异。
69名年龄在20至38岁之间的健康年轻成年人参与了本研究，其中包括40名低度近视者（平均±标准差球镜等效（MSE）屈光不正：-3.00±1.39D，范围：-6.00至-0.62D）和29名正视者（MSE：-0.05±0.09D，范围：-0.25至+0.12D）。在五个偏心度（中央凹、旁中央凹、周边凹；近周边和周边）和四个象限（鼻侧、颞侧、下方和上方）的垂直和水平子午线上测量广角CT、管腔厚度、基质厚度和CVI，同时控制一系列可能影响CT的外部因素。使用定制软件对OCT图像进行分割和二值化处理。
所有参与者的广角CT、管腔厚度和基质厚度平均显示出显著的地形变化，中央凹区域（分别为379±8μm、200±4μm、179±4μm）和周边区域（分别为275±8μm、161±4μm、114±4μm）呈现最厚和最薄区域（所有p<0.001）。广角CVI显示，从中央凹向周边偏心度增加时，百分比逐渐升高（血管化程度更高）（p<0.001）。与正视者相比，近视者的黄斑CT和脉络膜基质厚度显著更薄（p<0.05）。近视者（55.7±0.3%）的CVI略高于正视者（54.4±0.4%）（p<0.05）。
年轻成年人中的低度近视与黄斑区而非黄斑外区域的脉络膜显著变薄有关，脉络膜厚度的这种降低主要归因于脉络膜基质成分的变薄，而非管腔（血管）成分。
