Abstract
Purpose: :
To provide details of conceptualization and techniques employed to quantify adherence with amblyopia therapy in the Infant Aphakia Treatment Study (IATS).
Methods: :
Infants between one and 7 months of age (n=114) were randomly assigned to primary IOL implantation or to be left aphakic following removal of a unilateral congenital cataract. Visual correction for aphakic infants was provided by contact lens. Residual visual correction in the pseudophakic infants was provided by spectacles when needed. The protocol stipulated visual correction during all waking hours and patching of the untreated eye for 1-hour per day for each month of life up to 8 months of age. After 8 months of age, patching regimen was 50% of waking hours. We measured adherence for both patching and visual correction, as well as sleep-wake times, using two instruments: 1) 48-hour telephone recall (retrospective) interview conducted by a trained interviewer quarterly starting three months after surgery, and 2) annual prospective 7-day diary starting two months after surgery. The data were collected by the Data Coordinating Center (DCC); accuracy of parent reports was facilitated by assurances that the information would not be shared with clinical providers. Cronbach’s alpha was used to evaluate the reliability of our instruments.
Results: :
Reliabilities for percent adherence with amblyopia therapy ranged from 0.78-0.89 (patching = 0.78; glasses use = 0.89; contact lens use = 0.81). Reliability for sleep-wake time was slightly lower (alpha = 0.66). Reports of patching were based on time since surgery. More than half of caregivers reported achieving at least 75% of the prescribed hours of patching immediately after surgery: 72% at 2 months; 62% at 3 months after surgery. However, fewer than half achieved this degree of patching more than 6 months after surgery: 43% at 9 months; 42% at 1 year. Parents reporting no patching were as follows: 1% at 2 months; 2.7% at 3 months; 8.1% at 6 months; 9.4% at 9 months and 13.5% at 12 months after surgery.
Conclusions: :
Data on patching, visual correction and sleep can be reliably collected using either the prospective diary or the retrospective phone interview, and did not differ between the procedures. We observed a dramatic decline in patching adherence over the first twelve months after surgery. These data demonstrate trends in patching and visual correction by parents of very young children and may provide clues for improving adherence with amblyopia therapy in infants and toddlers.
Clinical Trial: :
www.clinicaltrials.gov NCT00212134
Keywords: amblyopia • clinical (human) or epidemiologic studies: systems/equipment/techniques • visual development: infancy and childhood