Most eyes with high-risk prethreshold ROP develop astigmatism by age 6

This study published in the December issue of Ophthalmology extended to the age of 6 the examination of astigmatism progression in Early Treatment of ROP study participants. Previous studies have reported on astigmatism prevalence up to age 3 in this cohort, which is composed of preterm infants with birth weight less than 1251 g in whom high-risk prethreshold ROP developed in one or both eyes. The current study reports that astigmatism consistently increased over time among the 401 study participants, regardless of whether they were randomized to early treatment or conventional management. By age 6, astigmatism reached at least 1.00 D in more than 50 percent of eyes and 2.00 D or greater in nearly 25 percent.

Presence of astigmatism was not influenced by timing of treatment, zone of acute-phase ROP or presence of plus disease. However, there was a trend toward higher prevalence of astigmatism and high astigmatism in eyes with ROP residua.

Most astigmatism was with-the-rule (75° to 105°). More eyes with type 2 than type 1 ROP had astigmatism by 6 years of age. The study’s authors say the reason for this remains unclear.

They say the study’s findings reinforce the importance of follow-up eye examinations through at least age 6 in infants with high-risk prethreshold ROP. Recognition of high astigmatism and astigmatism at the oblique axis is especially important in these patients because treatment of refractive amblyopia may be more successful with early intervention.