title: Incidence and main risk factors for severe retinopathy of prematurity in infants weighing less than 1000 grams in Brazil.
abstract: OBJECTIVE
  This study evaluated the incidence and risk factors for severe retinopathy of prematurity (ROP) in babies <1000 g at Porto Alegre, Brazil.
  
  
  METHODS
  Prospective cohort study including premature children with birth weight ≤1000 g was conducted. Main outcome was the occurrence of severe ROP needing treatment.
  
  
  RESULTS
  A total of 157 infants were included. Severe ROP occurred in 20 infants (12.7%). Nineteen patients were treated by laser photocoagulation. Main risk factors for severe ROP were gestational age (P = 0.029), infant's weight measured at sixth week of life (P < 0.001) and number of days of oxygen therapy under mechanical ventilation (P < 0.001). After logistic regression, infant's weight at sixth week of life and number of days in mechanical ventilation were associated to severe ROP.
  
  
  CONCLUSIONS
  We reported the incidence of 12.7% of severe ROP among babies born ≤ 1000 g in our institution. Laser photocoagulation was effective to stabilize the disease among 19 treated patients.
authors.affiliation: Department of Ophthalmology, Medical School, Federal University of Rio Grande do Sul, Hospital de Clínicas de Porto Alegre, RS 90035-903, Brazil.
authors.forename: João Borges
authors.initials: JB
authors.lastname: Fortes Filho
authors.forename: Bárbara Gastal
authors.initials: BG
authors.lastname: Borges Fortes
authors.forename: Marcia Beatriz
authors.initials: MB
authors.lastname: Tartarella
authors.forename: Renato Soibelmann
authors.initials: RS
authors.lastname: Procianoy
mesh_terms: D001724:Birth Weight; D001938:Brazil / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D011446:Prospective Studies; D012178:Retinopathy of Prematurity / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012720:Severity of Illness Index; D062606:Tertiary Care Centers; D014505:Urban Population
keywords: blindness; incidence; prematurity; prevention; retinopathy of prematurity; risk factors