Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK.
National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.
Sci Rep. 2020 Jul 22;10(1):12179. doi: 10.1038/s41598-020-67893-8.
This study demonstrates significant differences between the area of complete spatial summation (Ricco's area, RA) in eyes with and without non-pathological, axial myopia. Contrast thresholds were measured for six stimuli (0.01-2.07 deg) presented at 10º eccentricity in 24 myopic subjects and 20 age-similar non-myopic controls, with RA estimated using iterative two-phase regression analysis. To explore the effects of axial length-induced variations in retinal image size (RIS) on the measurement of RA, refractive error was separately corrected with (i) trial lenses at the anterior focal point (near constant inter-participant RIS in mm), and (ii) contact lenses (RIS changed with axial length). For spectacle corrected measurements, RA was significantly larger in the myopic group, with a significant positive correlation also being observed between RA and measures of co-localised peripheral ocular length. With contact lens correction, there was no significant difference in RA between the groups and no relationship with peripheral ocular length. The results suggest RA changes with axial elongation in myopia to compensate for reduced retinal ganglion cell density. Furthermore, as these changes are only observed when axial length induced variations in RIS are accounted for, they may reflect a functional adaptation of the axially-myopic visual system to an enlarged RIS.
本研究表明，正常眼与非病理性轴性近视眼中完全空间总和区域（Ricco 区域，RA）存在显著差异。在 24 名近视患者和 20 名年龄匹配的非近视对照组中，在 10°偏心处用 6 个刺激物（0.01-2.07 度）进行对比度阈值测量，RA 使用迭代两阶段回归分析进行估计。为了探索轴向长度引起的视网膜图像大小（RIS）变化对 RA 测量的影响，使用（i）在前焦点处的试镜（参与者间 RIS 基本不变，以毫米为单位）和（ii）隐形眼镜（RIS 随轴向长度变化）分别对屈光不正进行校正。对于眼镜校正测量，近视组的 RA 明显更大，并且 RA 与共定位周边眼长度的测量值之间也存在显著的正相关关系。用隐形眼镜校正时，两组之间的 RA 无显著差异，与周边眼长度也无关系。结果表明，近视患者的 RA 随眼轴伸长而变化，以补偿视网膜神经节细胞密度的降低。此外，由于仅当考虑到轴向长度引起的 RIS 变化时才观察到这些变化，因此它们可能反映了轴向近视视觉系统对扩大的 RIS 的功能适应。
