Alanazi Muteb, Caroline Patrick, Alshamrani Amane, Alanazi Turki, Liu Maria
Optometry Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
College of Optometry, Pacific University, Forest Grove, OR, USA.
Clin Ophthalmol. 2021 Nov 30;15:4573-4584. doi: 10.2147/OPTH.S334619. eCollection 2021.
To examine the regional distribution of choroidal thickness (ChT) and the diurnal variation in ChT and axial length (AL) over a wide range of myopic refractive error.
ChT was measured in thirty-four healthy young adults (age mean ± SD: 25.2 ± 2.8, range: 18-35 years) using spectral-domain optical coherence tomography and AL using an IOL-Master 500. Participants were divided into three refractive groups: emmetropes, myopes, and high myopes. We evaluated ChT in macular (foveal, parafovea, and perifovea) and peripheral regions (6-mm from the foveal pit) in four quadrants (superior, temporal, inferior, and nasal). To assess the diurnal variation, three measurement sessions of ChT and AL were taken at 8 AM, 12 PM, 4 PM.
ChT thins progressively towards the periphery. Superior and nasal quadrants exhibited the thickest (277 ± 73 µm) and thinnest (218 ± 89 µm) choroid, respectively. Higher myopic eyes showed an overall thinner choroid (237 ± 48 µm) compared to myopic eyes (264 ± 78 µm) (P < 0.05). Higher myopes exhibited a significant choroidal thinning in all quadrants except in the temporal quadrant (all p < 0.05). Both ChT and AL underwent a significant diurnal variation (p < 0.05). The ChT and AL diurnal variation amplitudes in higher myopes were significantly reduced (ChT: 14.6 ± 11, AL: 14.5 ± 13 µm), compared to those in emmetropes (ChT: 21.4 ± 15, AL: 21.3 ± 8.5 µm) and myopes (ChT: 19 ± 17, AL: 19 ± 9.7 µm). Diurnal variation amplitude in ChT did not differ significantly across quadrants and choroidal eccentricity regions (p > 0.05).
ChT distribution varies based on quadrant and eccentricity; superior choroid exhibited the thickest, and nasal showed the thinnest choroid. Higher myopes experience a reduced diurnal variation in ChT and AL.
研究在大范围近视屈光不正情况下脉络膜厚度（ChT）的区域分布以及ChT和眼轴长度（AL）的昼夜变化。
使用光谱域光学相干断层扫描技术测量34名健康年轻成年人（年龄均值±标准差：25.2±2.8，范围：18 - 35岁）的ChT，并使用IOL-Master 500测量AL。参与者被分为三个屈光组：正视眼组、近视眼组和高度近视眼组。我们评估了四个象限（上方、颞侧、下方和鼻侧）黄斑区（中心凹、中心凹旁和中心凹周围）和周边区域（距中心凹凹陷6毫米处）的ChT。为评估昼夜变化，在上午8点、中午12点、下午4下午4点进行了三次ChT和AL测量。
ChT向周边逐渐变薄。上方象限和鼻侧象限的脉络膜分别最厚（277±73微米）和最薄（218±89微米）。与近视眼（264±78微米）相比，高度近视眼的脉络膜总体更薄（237±48微米）（P<0.05）。除颞侧象限外，高度近视眼在所有象限均表现出明显的脉络膜变薄（所有p<0.05）。ChT和AL均经历了显著的昼夜变化（p<0.05）。与正视眼（ChT：21.4±15，AL：21.3±8.5微米）和近视眼（ChT：19±17，AL：19±9.7微米）相比，高度近视眼的ChT和AL昼夜变化幅度显著降低（ChT：14.6±11，AL：14.5±13微米）。ChT的昼夜变化幅度在各象限和脉络膜偏心区域之间无显著差异（p>0.05）。
ChT分布因象限和偏心度而异；上方脉络膜最厚，鼻侧脉络膜最薄。高度近视眼的ChT和AL昼夜变化减小。
