title: Ophthalmologic Outcome of Extremely Preterm Infants at 6.5 Years of Age: Extremely Preterm Infants in Sweden Study (EXPRESS).
abstract: OBJECTIVE
  This follow-up study of extremely preterm (EPT) children (<27 weeks' gestational age [GA] at birth) revealed major eye and visual problems in 37.9% (147 of 388) of all EPT infants and in 55.4% (67 of 121) of the most immature subgroups at 6.5 years of age. These major eye and visual problems were strongly associated with treatment-requiring retinopathy of prematurity (ROP).
  
  
  OBJECTIVE
  To investigate the ophthalmologic outcome of a national cohort of EPT children at 6.5 years of age and to evaluate the impact of prematurity and ROP.
  
  
  METHODS
  All surviving EPT children born in Sweden between April 1, 2004, and March 31, 2007, were included and compared with a matched term control group, as part of a prospective national follow-up study.
  
  
  METHODS
  Visual acuity, refraction in cycloplegia, and manifest strabismus were evaluated and compared with GA at birth and with treatment-requiring ROP.
  
  
  RESULTS
  The study cohort comprised 486 participants. The mean (SD) GA of the children who were included was 25 (1) weeks, and 45.7% (222 of 486) were female. At a median age of 6.6 years, 89.3% (434 of 486) of eligible EPT children were assessed and compared with 300 control group children. In the EPT group, 2.1% (9 of 434) were blind, 4.8% (21 of 434) were visually impaired according to the World Health Organization criteria, and 8.8% (38 of 434) were visually impaired according to the study criteria. Strabismus was found in 17.4% (68 of 390) and refractive errors in 29.7% (115 of 387) of the EPT children compared with 0% (0 of 299) and 5.9% (17 of 289), respectively, of the control children (P < .001). Altogether at 6.5 years of age, 37.9% (147 of 388) of the EPT children had some ophthalmologic abnormality compared with 6.2% (18 of 290) of the matched control group (95% CI of the difference, 26.1%-37.2%). When treatment-requiring ROP was adjusted for, no significant association between GA and visual impairment could be detected. For refractive errors, the association with GA remained after adjustment for treatment-requiring ROP (odds ratio, 0.72; 95% CI, 0.58-0.91 for each 1-week increment).
  
  
  CONCLUSIONS
  In a Swedish national cohort of EPT children at 6.5 years of age, major eye and visual problems were frequently found. Treatment-requiring ROP was a stronger impact factor than GA on visual impairment and strabismus, but not on refractive errors, as a whole. In modern neonatal intensive care settings, ophthalmologic problems continue to account for a high proportion of long-term sequelae of prematurity.
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Astrid Lindgren Children's Hospital, Stockholm, Sweden.
authors.forename: Kerstin M
authors.initials: KM
authors.lastname: Hellgren
authors.affiliation: Department of Ophthalmology, Lund University Hospital, Lund, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Tornqvist
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Jakobsson
authors.affiliation: Department of Ophthalmology, Umeå University, Umeå, Sweden.
authors.forename: Pia
authors.initials: P
authors.lastname: Lundgren
authors.affiliation: Department of Ophthalmology, Örebro University, Örebro, Sweden.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Carlsson
authors.affiliation: Centre of Reproduction Epidemiology, Department of Obstetrics and Gynecology, Institute of Clinical Sciences, University of Lund, Lund, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Källén
authors.affiliation: Section of Pediatrics, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Serenius
authors.affiliation: Section of Pediatric Ophthalmology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Hellström
authors.affiliation: Department of Neuroscience (Ophthalmology), Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Gerd
authors.initials: G
authors.lastname: Holmström