title: Retinopathy of prematurity: evaluation of risk factors.
abstract: OBJECTIVE
  The purpose of this study was to determine what risk factors play a role in the development of retinopathy of prematurity (ROP).
  
  
  METHODS
  Data were collected on 157 infants born and cared for in one institution between January 1991 and July 1994. Initially we evaluated all children enrolled in the study to determine potential risk factors for the development of ROP. We subsequently compared multiple variables for ROP positive singletons with ROP positive twins to determine ROP risk factors for each group and to determine if one group was more susceptible to a given risk factor.
  
  
  RESULTS
  Of the 157 infants examined, 72 infants (46%) developed ROP. Infants who developed ROP had a lower gestational age, a lower birth weight, a higher number of days on oxygen/ventilator, more days in the intensive care unit (ICU), a greater need for steroids and a higher incidence of sepsis when compared to infants who did not develop ROP. There was no significant difference noted between singleton and twin gestation infants that developed ROP when comparing gestational age, weight, ventilator time or length of ICU stay. Total number of days on oxygen therapy was higher in the singleton group and this difference did reach statistical significance.
  
  
  CONCLUSIONS
  Several risk factors are associated with a higher incidence of ROP. These variables may not be independent risk factors but may be a sign of the increased severity of illness associated with those infants who are born earlier with a lower birth weight. Multiple gestational births do not appear to increase the risk of developing ROP when compared to a similar group of singleton birth infants.
authors.affiliation: Ophthalmology Service, Walter Reed Army Medical Center, Washington DC, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Brown
authors.forename: A B
authors.initials: AB
authors.lastname: Thach
authors.forename: J C
authors.initials: JC
authors.lastname: Song
authors.forename: J L
authors.initials: JL
authors.lastname: Marx
authors.forename: R C
authors.initials: RC
authors.lastname: Kwun
authors.forename: D A
authors.initials: DA
authors.lastname: Frambach
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010100:Oxygen / Q000009:adverse effects / Q000627:therapeutic use; D012121:Respiration, Artificial / Q000009:adverse effects; D012178:Retinopathy of Prematurity / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014427:Twins
chemical_list: D010100:Oxygen