title: Incidence of retinopathy of prematurity in southwestern China and analysis of risk factors.
abstract: BACKGROUND
  The aim of this study was to screen for retinopathy of prematurity (ROP) in southwestern China and understand the prevalence and risk factors of ROP, which may provide evidence useful in the prevention and treatment of ROP.
  
  
  METHODS
  1864 preterm infants (gestational age of <37 weeks and birth weight of ≤2500 g) underwent ROP screening from January 2009 to November 2012 in Southwest China. The medical information of infants during perinatal period was reviewed, and risk factors of ROP were determined. A total of 1614 infants were recruited for final analysis.
  
  
  RESULTS
  Incidence of ROP was 12.8%. The first, second, third, and fourth stage of ROP was found in 64.6%, 29.6%, 3.4%, and 0.5% of infants, respectively. No fifth stage of ROP was observed. In addition, 7.7% of infants required surgical intervention. In our Department of Neonatology, the incidence of ROP was 20.0%, which was significantly higher than in non-hospitalized patients (9.9%). The incidence of ROP remained unchanged over the years. Independent risk factors of ROP included low birth weight (p=0.049), low gestational age (p=0.008), days of oxygen supplementation (p=0.008), and myocardial injury after birth (p=0.001).
  
  
  CONCLUSIONS
  The prevalence of ROP in preterm infants is relatively high in Southwest China, and low birth weight, low gestational age, days of oxygen supplementation, and myocardial injury after birth are independent risk factors for ROP.
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Southwest Hospital, Third Military Medical University, Chongqing, China (mainland).
authors.forename: Zheng-Qin
authors.initials: ZQ
authors.lastname: Yin
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Ning
authors.initials: N
authors.lastname: Ke
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Xin-Ke
authors.initials: XK
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Xiu-Rong
authors.initials: XR
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Kang
authors.initials: K
authors.lastname: Hu
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Hui
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Hong-Jian
authors.initials: HJ
authors.lastname: Long
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Kang-Lin
authors.initials: KL
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Zhi-Yu
authors.initials: ZY
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, Chongqing, China (mainland).
authors.forename: Lian-Hong
authors.initials: LH
authors.lastname: Pi
mesh_terms: D001724:Birth Weight; D002681:China / Q000453:epidemiology; D005865:Gestational Age; D006335:Heart Injuries / Q000150:complications; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects; D015995:Prevalence; D012178:Retinopathy of Prematurity / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors