Data_Sheet_1_Measuring the impact of suppression on visual acuity in children with amblyopia using a dichoptic visual acuity chart.docx

PurposeTo develop a novel dichoptic visual acuity chart that measures the impact of interocular suppression on the visual acuity of each eye when two eyes are open.
MethodsFifty-four subjects (19 anisometropic amblyopia, 20 treated amblyopia, and 15 normal children) participated in this study. The visual acuity that was tested under dichoptic-optotypes condition (i.e., presented optotypes to the untested eye) was compared with that under monocular condition (i.e., cover the untested eye with opaque patch). Visual acuity differences between these two conditions were compared among the three groups. The correlations between visual acuity differences and the depth of interocular suppression were then computed. Some participants performed the visual acuity test under dichoptic-luminance condition (i.e., presented mean luminance to the untested eye), and the test-retest reliability was established.
ResultsA reduced visual acuity of the non-dominant eye was found in the dichoptic-optotypes condition for the amblyopia group (P < 0.001) and the treated group (P = 0.001); the difference in the treated group was less than that in the amblyopia group (P < 0.001) but more than that in the normal group (P = 0.026). A significant correlation was found between the visual acuity differences and the depth of suppression, which was tested with a binocular phase combination task (P = 0.005). No change was found in the dichoptic-luminance condition.
ConclusionThe amblyopic eye and the previous amblyopic eye seem to suffer from a reduced visual acuity when two eyes are open due to suppression. This was successfully captured by our novel and reliable dichoptic-optotypes visual acuity chart.

研究目的：本研究旨在开发一种新型双眼分视视力表（dichoptic visual acuity chart），用于测量双眼同时开放时，眼间抑制（interocular suppression）对单眼视力的影响。
研究方法：本研究共纳入54名受试者，包括19名屈光参差性弱视（anisometropic amblyopia）患者、20名经治疗弱视患者及15名正常儿童。将双眼分视视标条件（dichoptic-optotypes condition，即向未检测眼呈现视标）下测得的视力，与单眼检测条件（即使用遮光眼罩遮盖未检测眼）下测得的视力进行对比。随后比较三组受试者在两种检测条件下的视力差值，并计算视力差值与眼间抑制深度的相关性。另有部分受试者在双眼分视亮度条件（dichoptic-luminance condition，即向未检测眼呈现平均亮度）下完成视力检测，以建立重测信度。
研究结果：弱视组与经治疗组在双眼分视视标条件下，非主导眼的视力均出现下降（弱视组P<0.001，经治疗组P=0.001）；经治疗组的视力差值小于弱视组（P<0.001），但大于正常组（P=0.026）。视力差值与通过双眼相位组合任务（binocular phase combination task）测得的眼间抑制深度呈显著相关（P=0.005）。而在双眼分视亮度条件下未观察到视力变化。
研究结论：当双眼同时开放时，弱视眼与既往弱视眼会因眼间抑制出现视力下降，这一效应可通过本研究开发的新型可靠双眼分视视标视力表有效捕捉。