title: Refractive outcome of prethreshold retinopathy of prematurity treated by diode laser: follow-up at 5 years.
abstract: BACKGROUND
  The purpose of this study was to evaluate the refraction of eyes treated with diode laser photocoagulation for prethreshold retinopathy of prematurity (ROP) at a mean of 5 years after treatment.
  
  
  METHODS
  Fifty infants with prethreshold ROP treated with diode laser at Hanoi Childrens' Hospital during the period 2008 to 2009 were reviewed. Refractive error was identified by cycloplegic refraction with Cyclogyl 1%. Myopia was divided into two categories based on magnitude: high myopia (more than -5.00 D) and low myopia (between 0 and -5.00 D). Hypermetropia was subdivided into low hypermetropia (between 0 and +5.00 D) and high hypermetropia (greater than +5.00 D). Astigmatism was classified as high if >2.00 D. Eyes with media opacification that interferes with retinoscopy were excluded. The refractive outcome was correlated with birth weight and gestational age. The anatomical and visual outcomes were recorded.
  
  
  RESULTS
  One hundred eyes from 50 infants were included in the study. The mean birth weight was 1,426.4 g and the mean gestational age was 29.88 weeks. After 5 years of follow-up, the average spherical equivalent for 100 eyes was -2.87 D. On cycloplegic retinoscopy, high myopia (more than -5.00 D) was seen in 32% of eyes. Twenty (20%) eyes had nonsignificant hypermetropia, and high hypermetropia (more +5.00 D) was seen in only one eye (1%). The prevalence of astigmatism and high astigmatism (more than -2.00 D) was 79% and 49%, respectively. Three infants (6%) had esotropia and two infants (4%) had exotropia. None of the infants had nystagmus.
  
  
  CONCLUSIONS
  The majority of patients who underwent diode laser therapy for prethreshold ROP had favourable anatomical and visual outcomes. High refractive error is common and may be the cause of visual impairment.
authors.affiliation: Department of Ophthalmology, Thanhhoa Paediatrics Hospital, Thanhhoa City, Vietnam, Australia ; Save Sight Institute and Discipline of Clinical Ophthalmology, University of Sydney, NSW, Australia.
authors.forename: Phuoc Huu
authors.initials: PH
authors.lastname: Nguyen
authors.affiliation: Save Sight Institute and Discipline of Clinical Ophthalmology, University of Sydney, NSW, Australia.
authors.forename: Caroline
authors.initials: C
authors.lastname: Catt
authors.affiliation: Paediatrics Department, Vietnam National Ínstitute of Ophthalmology, Hanoi Medical University, Hanoi, Vietnam.
authors.forename: Tinh Xuan
authors.initials: TX
authors.lastname: Nguyen
authors.affiliation: Ophthalmology Department, Hanoi Medical University, Hanoi, Vietnam ; Oculoplastics and Cosmesis Department, Vietnam National Ínstitute of Ophthalmology, Hanoi, Vietnam.
authors.forename: Van Trong
authors.initials: VT
authors.lastname: Pham
keywords: astigmatism; hypermetropia; myopia; refractive outcome