FEB 20, 2012
This analysis found that most children with a history of high-risk prethreshold ROP develop strabismus at some time during the first 6 years of life.
Subjects were children in the randomized Early Treatment for Retinopathy of Prematurity (ETROP) trial examined through age 6. All subjects had birth weights of less than 1,251 g and were born between October 2000 and September 2002 and screened at one of 26 medical centers.
The prevalence of strabismus at age 6, even with favorable acuity scores in both eyes, was 25.4 percent, and with favorable structural outcomes in both eyes, it was 34.2 percent. Most strabismus was constant at both the 9-month (62.7 percent) and the 6-year examination (72.3 percent), irrespective of whether surgical correction was performed, with delayed stabilization of alignment common. Most of the 103 children who were strabismic at the 9-month examination remained so (77; 74.8 percent), although some children who were strabismic in infancy showed normal alignment at age 6, even without surgery.
Of children categorized as visually impaired due to ocular or cerebral causes, 80 percent were strabismic at the 6-year examination. Of the 103 study participants who were strabismic at 9 months, 77 (74.8%) remained so at 6 years.
After multiple logistic regression analysis, risk factors for strabismus were abnormal fixation behavior in one or both eyes (P < 0.001), history of amblyopia (P < 0.003), unfavorable structural outcome in one or both eyes (P = 0.025) and history of anisometropia (P = 0.04). All of these factors have been previously associated with strabismus at age 1 in infants with a history of prematurity.
The authors say the potential for binocular vision is likely to be relatively low in this population, due to factors attributable to ocular or visual function abnormalities. They advise caution when considering expectations for normal alignment or binocular function among children with a history of high-risk prethreshold ROP.