title: [Retinopathy of prematurity in extremely low birth weight infants: a Tokyo multicenter study].
abstract: OBJECTIVE
  To investigate how the increase in survival rate in extremely low birth weight (a birth weight of 1,000 g or less) infants had affected the incidence of retinopathy of prematurity (ROP) and the frequency of laser treatment.
  
  
  METHODS
  We retrospectively reviewed the medical records of 122 surviving premature infants with birthweights less than 1,000 g to determine the severity of ROP observed at 16 neonatal intensive care units in Tokyo between April and October 2002.
  
  
  RESULTS
  The survival rate was 85.6%. The mean gestational age was 26.74 weeks and the mean birth weight was 782.25 g. One-hundred-and-five infants (86.1%) developed ROP, fifty (41.0%) received laser treatment, and six (4.9%) had retinal detachment. The median postmenstrual age (gestational age at birth plus chronological age in weeks, PMA) at the onset of ROP was 32.5 weeks, and the first laser treatment was performed at the median PMA of 35.7 weeks.
  
  
  CONCLUSIONS
  In these extremely low birth weight infants, there was an increase in the survival rate and in the incidence of severe ROP that progressed to the stage that required treatment.
authors.affiliation: Department of Neonatology, Tokyo Metropolitan Bokutoh Hospital, Japan.
authors.forename: Miina
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authors.lastname: Hiraoka
authors.forename: Toyoko
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authors.lastname: Watanabe
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kawakami
authors.forename: Rei
authors.initials: R
authors.lastname: Ito
authors.forename: Itsuro
authors.initials: I
authors.lastname: Takigawa
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Suzumura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Yoshimi
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authors.lastname: Kubota
authors.forename: Yoshihiro
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authors.lastname: Hayashi
authors.forename: Masaki
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kazuhiko
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authors.lastname: Kabe
authors.forename: Akira
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authors.lastname: Nishida
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kondo
authors.forename: Toshio
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ueda
authors.forename: Tasuku
authors.initials: T
authors.lastname: Miyajima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Muramatsu
authors.forename: Izumi
authors.initials: I
authors.lastname: Sakuma
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Toyoguchi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Shima
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takada
authors.forename: Reifui
authors.initials: R
authors.lastname: Nakayama
authors.forename: Atsuto
authors.initials: A
authors.lastname: Hosaka
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Ren
authors.initials: R
authors.lastname: Hasegawa
authors.forename: Jun
authors.initials: J
authors.lastname: Hoshi
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Soeda
authors.forename: Mihoko
authors.initials: M
authors.lastname: Toyoda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Saito
mesh_terms: D001724:Birth Weight; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D053685:Laser Therapy; D012178:Retinopathy of Prematurity / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors; D014041:Tokyo / Q000453:epidemiology