Han S H, Kim S K, Lee J B, Lee M S
Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
Yonsei Med J. 1998 Aug;39(4):363-6. doi: 10.3349/ymj.1998.39.4.363.
In order to verify that the effects of diffusion blur on Snellen and grating acuity in amblyopic eyes resemble those obtained from the peripheral or central retina in normal controls, we conducted the following experiment using a liquid crystal window (Edmund Scientific Co.) to produce diffusion blur on Snellen and grating acuity. Spatial frequencies used for a Snellen chart and Teller acuity card were 3.2, 6.5, 13.0, 26.0 cyc/cm at a working distance of 55 cm. The values of diffusive blur on central and peripheral visual acuity obtained from 20 normal healthy control eyes were compared with those values of central visual acuity in 26 amblyopic eyes. The diffusion blur had a strong negative effect on both Snellen and grating acuity in amblyopic eyes, but it had more potent effects on grating acuity (p < 0.05). The diffusion blur values obtained from the central amblyopic retina were more compatible with those of the central retina than with those of the peripheral retina in the control group (p > 0.05). Snellen acuity obtained from diffusion blur overestimated grating acuity in the normal central acuity group and amblyopic central acuity group. The result of this investigation demonstrated that the liquid crystal diffusion blur had a strong negative effect on both Snellen and grating acuity and suggested that the visual function of an amblyopic retina resembled that of a normal central retina.
为了验证扩散模糊对弱视眼的Snellen视力和光栅视力的影响是否类似于正常对照眼中从周边或中央视网膜获得的影响，我们使用液晶窗口（Edmund Scientific Co.）进行了以下实验，以在Snellen视力和光栅视力上产生扩散模糊。在55厘米的工作距离下，用于Snellen视力表和Teller视力卡的空间频率为3.2、6.5、13.0、26.0周/厘米。将20只正常健康对照眼获得的中央和周边视力的扩散模糊值与26只弱视眼的中央视力值进行比较。扩散模糊对弱视眼的Snellen视力和光栅视力均有强烈的负面影响，但对光栅视力的影响更强（p<0.05）。与对照组周边视网膜的扩散模糊值相比，弱视中央视网膜获得的扩散模糊值与中央视网膜的扩散模糊值更相符（p>0.05）。在正常中央视力组和弱视中央视力组中，由扩散模糊获得的Snellen视力高估了光栅视力。本研究结果表明，液晶扩散模糊对Snellen视力和光栅视力均有强烈的负面影响，并表明弱视视网膜的视觉功能类似于正常中央视网膜的视觉功能。
