Association Between Occlusion Therapy and Optotype Visual Acuity in Children Using Data From the Infant Aphakia Treatment Study: A Secondary Analysis of a Randomized Clinical Trial

Abstract

Importance: Patching has been a mainstay in treating unilateral congenital cataract. However, its efficacy has not been rigorously assessed.

Objective: To examine the association between patching and visual acuity in a cohort of children treated for unilateral congenital cataract.

Design, setting, and participants: This study was a secondary analysis of a randomized clinical trial (Infant Aphakia Treatment Study) of infants born from August 1, 2004, through December 31, 2008, who were treated with 1 of 2 treatments for unilateral congenital cataract and followed up to 5 years of age. Data analysis was performed from March 1, 2013, to March 1, 2016.

Interventions: Cataract extraction and randomization to receipt of an intraocular lens vs being left aphakic for the first 5 years of life.

Main outcomes and measures: Caregivers reported patching in the previous 48 hours in quarterly semistructured telephone interviews. The mean number of hours of patching per day was calculated from surgery to the first birthday (n = 92) and between 12 and 48 months of age (n = 102). Monocular optotype acuity was assessed at 4½ years of age by a traveling examiner using the Aphakia Treatment Study HOTV protocol.

Results: The Infant Aphakia Treatment Study enrolled 114 children; 57 were randomized to each treatment group. At 4½ years of age, optotype visual acuity was assessed in 112 children. The current analyses exclude an additional 3 children (2 who had adverse events that limited visual potential and 1 who had Stickler syndrome), leaving 109 total children analyzed (59 female [54.1%] and 92 white [84.4%]). Caregivers reported patching their children a mean (SD) of 3.73 (1.47) hours per day in the first year of life and 3.43 (2.04) hours per day thereafter. An association between reported patching and treatment was not identified (mean difference in first year, -0.29 hours per day; 95% CI, -0.90 to 0.33 hours per day; mean difference between 12 and 48 months of age, -0.40 hours per day; 95% CI, -1.20 to 0.40 hours per day). Visual acuity was associated with reported hours of patching in the first year of life (r = -0.32; 95% CI, -0.49 to -0.13) and between 12 and 48 months of age (r = -0.36; 95% CI, -0.52 to -0.18). However, patching accounted for less than 15% of the variance in logMAR acuity at 4½ years of age.

Conclusions and relevance: These results support the association of occlusion throughout the preschool years with improved visual acuity in infants treated for unilateral congenital cataract. However, similar visual outcomes were achieved with varying amounts of patching. These conclusions should be interpreted in the context of limitations related to generalizability from incomplete data collected in a clinical trial.

Trial registration: clinicaltrials.gov Identifier: NCT00212134.

Figures

Figure 1

CONSORT Diagram for the Infant Aphakia Treatment Study

Figure 2

Scatterplots showing the relationship between optotype visual acuity at 4 ½ years of age and reported average hours of daily patching in (a) the 1st year of life and (b) between 24 and 48 months of life

Figure 3

Boxplot showing the relationship between reported hours of patching in the first year of life and between 12 and 48 months of life and optotype visual acuity at 4 ½ years of age in the Infant Aphakia Treatment Study. The boxes represent the interquartile range (i.e., 25th percentile to 75th percentile) of visual acuity associated with each combination of patching in the 1st year of life and patching between 12 and 48 months of age, with the whiskers representing the full range of vision excluding any outliers which are shown as circles. The center line indicates the median visual acuity.