SKILL CARD RESULTS IN AMBLYOPIC CHILDREN

Two experiments were undertaken to assess high contrast-high luminance (HCHL) and low contrast-low luminance (LCLL) visual acuity as measure d with the Smith-Kettlewell Institute Low Luminance (SKILL) card, in c hildhood amblyopia. In experiment 1, HCHL and LCLL visual acuity was m easured in 11 amblyopic children and in 12 normal children of similar age. The results revealed that HCHL visual acuity was similar in the n ormal eyes and in the amblyopes' dominant eyes, and was abnormal in 91 % of the amblyopic eyes. LCLL visual acuity was significantly worse in normal eyes compared to the amblyopes' dominant eyes, and was abnorma l in only 64% of the amblyopic eyes. In experiment 2, HCHL and LCLL vi sual acuity was measured in seven previously tested amblyopic children , after a 5-month interval, and in six additional amblyopic children. In the amblyopic children who were tested twice, significant test-rete st reliability for HCHL and LCLL visual acuity was found and visual ac uity varied by 3.6%. The results of experiment 2 corroborated the resu lts of experiment 1 from the amblyopic children. It is concluded that visual acuity in the amblyopic eye tends to normalize under low contra st-low luminance conditions. In addition, the mechanism(s) underlying amblyopia appear also to influence the dominant eye, resulting in supe rior visual acuity under low contrast-low luminance conditions.