Correlation of monocular grating acuity at age 12 months with recognition acuity at age 4.5 years: findings from the Infant Aphakia Treatment Study

Purpose To determine whether grating acuity at age 12 months can be used to predict recognition acuity at age 4.5 years in children treated for unilateral congenital cataract enrolled in the Infant Aphakia Treatment Study (IATS). Methods Traveling testers assessed monocular grating acuity at 12 months of age (Teller Acuity Card Test [TACT]) and recognition acuity at 4.5 years of age (Amblyopia Treatment Study Electronic Visual Acuity Testing, HOTV) in children treated for visually significant monocular cataract in the IATS. Spearman rank correlation was used to evaluate the relationship between visual acuities at the two ages in the treated eyes. Results Visual acuity data at both ages were available for 109 of 114 children (96%). Grating acuity at 12 months of age and recognition acuity at 4.5 years of age were significantly correlated for the treated eyes ( r spearman  = 0.45; P  = 0.001). At age 4.5 years, 67% of the subjects who had grating acuity at 12 months of age within the 95% predictive limits in their treated eye demonstrated recognition acuity better than 20/200. Similarly, at age 4.5 years 67% of the subjects who had grating acuity at age 12 months below the 95% predictive limits in their treated eye demonstrated recognition acuity of 20/200 or worse. Conclusions A single grating acuity assessment at age 12 months predicts recognition acuity in a child treated for unilateral congenital cataract in only two-thirds of cases. Clinicians should consider other factors, such as patching compliance and age at surgery, when using an early grating acuity assessment to modify treatment.