Department of Visual Neuroscience, UCL Institute of Ophthalmology, London, United Kingdom.
Invest Ophthalmol Vis Sci. 2011 Mar 10;52(3):1275-80. doi: 10.1167/iovs.09-4334.
To assess the effect on visual acuity of compensating fixation instability by controlling retinal image motion in people with macular disease.
Ten patients with macular disease participated in this study. Crowded and noncrowded visual acuity were measured using an eye tracking system to compensate for fixation instability. Four conditions, corresponding to four levels of retinal image motion, were tested: no compensation (normal motion), partial compensation (reduced motion), total compensation (no motion), and overcompensation (increased motion). Fixation stability and the number of preferred retinal loci were also measured.
Modulating retinal image motion had the same effect on crowded and noncrowded visual acuity (P = 0.601). When fixation instability was overcompensated, acuity worsened by 0.1 logMAR units (P < 0.001) compared with baseline (no compensation) and remained equal to baseline for all other conditions.
In people with macular disease, retinal image motion caused by fixation instability does not reduce either crowded or noncrowded visual acuity. Acuity declines when fixation instability is overcompensated, showing limited tolerance to increased retinal image motion. The results provide evidence that fixation instability does not improve visual acuity and may be a consequence of poor oculomotor control.
通过控制黄斑病变患者的视网膜像运动来评估对视力（敏锐度）的影响。
本研究纳入了 10 名黄斑病变患者。使用眼动追踪系统补偿注视不稳定，测量拥挤视力和非拥挤视力。测试了四种条件，对应四种视网膜像运动水平：无补偿（正常运动）、部分补偿（减少运动）、完全补偿（无运动）和过补偿（增加运动）。还测量了注视稳定性和最佳视网膜位置数量。
调制视网膜像运动对拥挤视力和非拥挤视力的影响相同（P=0.601）。当注视不稳定被过补偿时，与基线（无补偿）相比，视力下降了 0.1 个 logMAR 单位（P<0.001），而在所有其他条件下，视力与基线相同。
在黄斑病变患者中，注视不稳定引起的视网膜像运动不会降低拥挤或非拥挤视力。当注视不稳定被过补偿时，视力会下降，表明对增加的视网膜像运动的容忍度有限。这些结果提供了证据表明，注视不稳定不会提高视力，可能是眼球运动控制不佳的结果。
