School of Optometry and Vision Sciences, Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.
Sci Rep. 2020 Mar 18;10(1):4946. doi: 10.1038/s41598-020-61914-2.
Contrast sensitivity is mostly used as a tool for testing aspects of visual functions. Infantile nystagmus is a pathological phenomenon that affects the spatial-temporal visual functions due to spontaneous oscillating movements of the eyes. We examined the spatial-temporal aspects of nystagmus perception, aiming to investigate the mechanisms underlying the deterioration of their visual performance. We tested the monocular and binocular contrast sensitivity of nystagmus and normally sighted subjects by measuring contrast detection of a Gabor target with spatial frequencies slightly above the cutoff threshold of each subject (nystagmus ~3; controls = 9cpd; presentation times 60-480 ms). The dominant eye of nystagmus revealed large differences over the non-dominant eye, highlighting the superiority of the dominant over the non-dominant eye in nystagmus. In addition, binocular summation mechanism was impaired in majority of the nystagmus subjects. Furthermore, these differences are not attributed to differences in visual acuity. Moreover, the visual performance in nystagmus continue to improve for longer presentation time compared with controls and was longer in the poor eye. Since the results are not due to differences in eye movements and strabismus, we suggest that the differences are due to developmental impairment in the visual system during the critical period.
对比敏感度主要用作测试视觉功能方面的工具。婴儿性眼球震颤是一种病理性现象，由于眼睛的自发性摆动运动，会影响时空视觉功能。我们检查了眼球震颤感知的时空方面，旨在研究导致其视觉表现恶化的机制。我们通过测量略微高于每个受试者截止阈值的空间频率的 Gabor 目标的对比度检测，测试了眼球震颤和正常视力受试者的单眼和双眼对比敏感度（眼球震颤~3；对照组=9cpd；呈现时间 60-480ms）。眼球震颤的主导眼与非主导眼之间存在很大差异，突出了主导眼在眼球震颤中的优势。此外，大多数眼球震颤受试者的双眼总和机制受损。此外，这些差异不是由于视力差异引起的。此外，与对照组相比，眼球震颤的视觉表现随着呈现时间的延长而持续提高，并且在视力较差的眼睛中持续时间更长。由于这些结果不是由于眼球运动和斜视的差异引起的，因此我们认为这些差异是由于在关键期内视觉系统的发育障碍引起的。
