弱視患者之對比敏感機能―使用VCTS 6500之經驗

Contrast sensitivity functions were measured, by using VCTS 6500, in 34 Amblyopes and in normal controls. All of the amblyopic eyes had visual acuity of 0.7 or less. There were two purposes of this study: the first was to quantify the contrast sensitivity losses in different forms of amblyopia; and the second was to determine the relationship between improvements in contrast sensitivity and Landolt's acuity. Our findings revealed both isometropic and anisometropic amblyopia had impairments of contrast sensitivity in the middle and high spatial frequency bands. After therapy a few patients had contrast sensitivity function increased only to some subnormal levels despite normal Landolt's acuity. No parallel relationship was found between improvements in contrast sensitivity and Landolt's acuity. Thus, visual acuity alone cannot be regarded as sufficient to quantify the effects of amblyopia therapy. Possibly amblyopia should be redefined as a reduction in visual acuity in association with in contrast sensitivity. Both parameters should be estimated.