title: Astigmatism progression in the early treatment for retinopathy of prematurity study to 6 years of age.
abstract: OBJECTIVE
  To examine the prevalence of astigmatism (≥ 1.00 diopter [D]) and high astigmatism (≥ 2.00 D) from 6 months after term due date to 6 years of age in preterm children with birth weight of less than 1251 g in whom high-risk prethreshold retinopathy of prematurity (ROP) developed and who participated in the Early Treatment for ROP study.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Four hundred one infants in whom high-risk prethreshold ROP developed in 1 or both eyes and were randomized to early treatment (ET) versus conventional management (CM). Refractive error was measured by cycloplegic retinoscopy. Eyes were excluded if they underwent additional retinal, glaucoma, or cataract surgery.
  
  
  METHODS
  Eyes were randomized to receive laser photocoagulation at high-risk prethreshold ROP or to receive treatment only if threshold ROP developed.
  
  
  METHODS
  Astigmatism and high astigmatism at each study visit.
  
  
  RESULTS
  For both ET and CM eyes, there was a consistent increase in prevalence of astigmatism over time, increasing from 42% at 4 years to 52% by 6 years for the group of ET eyes and from 47% to 54%, respectively, in the CM eyes. There was no statistically significant difference between the slopes (rate of change per month) of the ET and CM eyes for both astigmatism and high astigmatism (P = 0.75).
  
  
  CONCLUSIONS
  By 6 years of age, astigmatism of 1.00 D or more developed in more than 50% of eyes with high-risk prethreshold ROP, and nearly 25% of such eyes had high astigmatism (≥ 2.00 D). 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°-105°). More eyes with type 2 than type 1 ROP had astigmatism by 6 years. These findings reinforce the need for follow-up eye examinations through early grade school years in infants with high-risk prethreshold ROP.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Departments of Ophthalmology and Pediatrics, Cardinal Glennon Children's Medical Center, Saint Louis University School of Medicine, St Louis, Missouri 63104, USA. davittb@slu.edu
authors.forename: Bradley V
authors.initials: BV
authors.lastname: Davitt
authors.forename: Graham E
authors.initials: GE
authors.lastname: Quinn
authors.forename: David K
authors.initials: DK
authors.lastname: Wallace
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hardy
authors.forename: Betty
authors.initials: B
authors.lastname: Tung
authors.forename: Dejian
authors.initials: D
authors.lastname: Lai
authors.forename: William V
authors.initials: WV
authors.lastname: Good
mesh_terms: D000208:Acute Disease; D001251:Astigmatism / Q000453:epidemiology* / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018450:Disease Progression; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D017075:Laser Coagulation; D015995:Prevalence; D012178:Retinopathy of Prematurity / Q000503:physiopathology / Q000601:surgery*; D042262:Retinoscopy; D014481:United States / Q000453:epidemiology; D014792:Visual Acuity / Q000502:physiology