title: Natural history of retinopathy of prematurity: two-year outcomes of a prospective study.
abstract: OBJECTIVE
  To investigate the 2-year outcomes of the natural history of retinopathy of prematurity (ROP) in Taiwan.
  
  
  METHODS
  A prospective study was conducted at two tertiary medical centers. Premature infants were screened and examined for ROP. The postmenstrual ages of developing each stage of ROP and the associated risk factors were recorded.
  
  
  RESULTS
  A total of 698 infants were included. The incidences of ROP and treatment-requiring ROP in all patients with ROP were 29.7% and 37.2%. When only including patients with birth weight of 1,250 g or less, the incidences were 62.2% and 39.1%, respectively. In patients with ROP with birth weight over 1,250 g, 25% of them developed treatment-requiring ROP. The median postmenstrual ages for the development of Stage 1, Stage 2, and Type 1 ROP were 33.0, 34.0, and 34.7 weeks, respectively. Gestational age at birth and birth weight were the most important factors associated with treatment-requiring ROP (hazard ratios of 0.3 and 0.6).
  
  
  CONCLUSIONS
  Our hospital-based study reveals an earlier postmenstrual age of developing ROP in this Asian population than in the Early Treatment for ROP study. Infants with birth weight over 1,250 g could still develop treatment-requiring ROP. Suboptimal oxygen control, different genetic dispositions among different races, inconsistencies in ROP diagnosis, and earlier screening might account for such a phenomenon.
authors.affiliation: *Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan; †College of Medicine, Chang Gung University, Taoyuan, Taiwan; ‡Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan; §Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan; ¶Graduate Institute of Clinical Medical Science, Chang Gung University, Taoyuan, Taiwan; **Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taoyuan, Taiwan; and ††Biostatistical Center for Clinical Research, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Yi-Hsing
authors.initials: YH
authors.lastname: Chen
authors.forename: Rey-In
authors.initials: RI
authors.lastname: Lien
authors.forename: Shawn
authors.initials: S
authors.lastname: Tsai
authors.forename: Chee-Jen
authors.initials: CJ
authors.lastname: Chang
authors.forename: Chi-Chun
authors.initials: CC
authors.lastname: Lai
authors.forename: An-Ning
authors.initials: AN
authors.lastname: Chao
authors.forename: Kuan-Jen
authors.initials: KJ
authors.lastname: Chen
authors.forename: Yih-Shiou
authors.initials: YS
authors.lastname: Hwang
authors.forename: Nan-Kai
authors.initials: NK
authors.lastname: Wang
authors.forename: Yen-Po
authors.initials: YP
authors.lastname: Chen
authors.forename: Tun-Lu
authors.initials: TL
authors.lastname: Chen
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Wu
mesh_terms: D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D015997:Neonatal Screening; D009887:Ophthalmoscopy; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology