Nizawa Tomohiro, Baba Takayuki, Kitahashi Masayasu, Oshitari Toshiyuki, Yamamoto Shuichi
Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chiba, Japan.
Clin Ophthalmol. 2017 Nov 14;11:2011-2015. doi: 10.2147/OPTH.S146831. eCollection 2017.
To determine the differences in the retinal sensitivities obtained by microperimetry with a single cross or a circular fixation target in normal individuals.
Thirty-two eyes of 16 healthy volunteers (mean age 28.9±1.4 years, range 24-44 years) were studied. The retinal sensitivity of the central 0 degrees and of the mean central 2 degrees consisting of 8 points were determined independently using the two different fixation targets with Microperimeter 3. The Goldmann III stimulus with a luminance of 1.0 cd/m was presented for 200 ms on a white background.
The retinal sensitivity of the central 0 degrees was significantly better with the circular target than that with the cross target (=0.003, right eyes; =0.001, left eyes). The mean retinal sensitivity in the central 2 degrees was not significantly different between the cross and circular fixation targets. (=0.07, right eyes; =0.08, left eyes).
These results indicate that the circular fixation target is a better target to use to evaluate the central retinal sensitivity. The difference in the retinal sensitivity is most likely due to the cross fixation target overlapping the test stimulus target.
确定在正常个体中，使用单个十字形或圆形注视目标通过微视野计获得的视网膜敏感度差异。
对16名健康志愿者（平均年龄28.9±1.4岁，范围24 - 44岁）的32只眼睛进行研究。使用微视野计3分别使用两种不同的注视目标独立测定中央0度以及由8个点组成的中央平均2度的视网膜敏感度。在白色背景上以1.0 cd/m的亮度呈现Goldmann III刺激200毫秒。
圆形目标时中央0度的视网膜敏感度显著优于十字形目标（右眼P = 0.003；左眼P = 0.001）。十字形和圆形注视目标之间中央2度的平均视网膜敏感度无显著差异（右眼P = 0.07；左眼P = 0.08）。
这些结果表明，圆形注视目标是评估中央视网膜敏感度更好的目标。视网膜敏感度的差异很可能是由于十字形注视目标与测试刺激目标重叠所致。
