Zhang Tianjiao, Godara Pooja, Blanco Ernesto R, Griffin Russell L, Wang Xiaolin, Curcio Christine A, Zhang Yuhua
Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama.
Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama.
Am J Ophthalmol. 2015 Aug;160(2):290-300.e1. doi: 10.1016/j.ajo.2015.04.034. Epub 2015 Apr 30.
To assess between- and within-individual variability of macular cone topography in the eyes of young adults.
Observational case series.
Cone photoreceptors in 40 eyes of 20 subjects aged 19-29 years with normal maculae were imaged using a research adaptive optics scanning laser ophthalmoscope. Refractive errors ranged from -3.0 diopters (D) to 0.63 D and differed by <0.50 D in fellow eyes. Cone density was assessed on a 2-dimensional sampling grid over the central 2.4 mm × 2.4 mm. Between-individual variability was evaluated by coefficient of variation (COV). Within-individual variability was quantified by maximum difference and root mean square (RMS). Cones were cumulated over increasing eccentricity.
Peak densities of foveal cones are 168 162 ± 23 529 cones/mm(2) (mean ± SD) (COV = 0.14). The number of cones within the cone-dominated foveola (0.8-0.9 mm diameter) is 38 311 ± 2319 (COV = 0.06). The RMS cone density difference between fellow eyes is 6.78%, and the maximum difference is 23.6%. Mixed-model statistical analysis found no difference in the association between eccentricity and cone density in the superior/nasal (P = .8503), superior/temporal (P = .1551), inferior/nasal (P = .8609), and inferior/temporal (P = .6662) quadrants of fellow eyes.
New instrumentation imaged the smallest foveal cones, thus allowing accurate assignment of foveal centers and assessment of variability in macular cone density in a large sample of eyes. Though cone densities vary significantly in the fovea, the total numbers of foveolar cones are very similar both between and within subjects. Thus, the total number of foveolar cones may be an important measure of cone degeneration and loss.
评估年轻成年人眼中黄斑区视锥细胞地形图的个体间和个体内变异性。
观察性病例系列。
使用研究型自适应光学扫描激光检眼镜对20名年龄在19 - 29岁、黄斑正常的受试者的40只眼睛中的视锥光感受器进行成像。屈光不正范围为-3.0屈光度（D）至0.63 D，双眼差异<0.50 D。在中央2.4 mm×2.4 mm的二维采样网格上评估视锥细胞密度。个体间变异性通过变异系数（COV）进行评估。个体内变异性通过最大差异和均方根（RMS）进行量化。视锥细胞随着偏心度增加而累积。
中央凹视锥细胞的峰值密度为168162±23529个视锥细胞/mm²（平均值±标准差）（COV = 0.14）。视锥细胞占主导的中央小凹（直径0.8 - 0.9 mm）内的视锥细胞数量为38311±2319个（COV = 0.06）。双眼之间视锥细胞密度的RMS差异为6.78%，最大差异为23.6%。混合模型统计分析发现，在双眼的上/鼻侧（P = 0.8503）、上/颞侧（P = 0.1551）、下/鼻侧（P = 0.8609）和下/颞侧（P = 0.6662）象限中，偏心度与视锥细胞密度之间的关联无差异。
新仪器对最小的中央凹视锥细胞进行了成像，从而能够准确确定中央凹中心，并评估大量眼睛样本中黄斑区视锥细胞密度的变异性。尽管中央凹处视锥细胞密度差异显著，但受试者之间和受试者内部的中央小凹视锥细胞总数非常相似。因此，中央小凹视锥细胞总数可能是视锥细胞变性和丢失的一项重要指标。
