Introduction: Children born extremely preterm have high risk of visual impairment due to retinopathy of prematurity (ROP) and cerebral lesions.
Objective: The aim of this study was to investigate the frequency of ROP and visual impairment as defined by the World Health Organization (WHO), with respect to gender in two hospital-based groups of children born at the limit of viability.
Patients and methods: A retrospective chart review was conducted for all children (n = 114), born before 25 gestational weeks and screened for ROP at Karolinska hospital in Stockholm and Sahlgrenska hospital in Gothenburg between 1990 and 2002. Maximal ROP stages, treatment for ROP and visual acuity (VA), with correction when needed at latest available visit, were recorded.
Results: Altogether 97.4% had ROP, 74.6% developed proliferative disease (stage >/= 3) and 63.2% were treated with retinal ablation. Normal VA (>/=0.8) in at least one eye was found in 50.5% of all and in significantly more girls (61.5%) than boys (34.8%) (p = 0.006), while visual impairment (VA < 0.33) was more common in boys (32.6%) than in girls (9.2%) (p = 0.004).
Conclusion: A large proportion of children, especially boys, born at the level of viability are visually impaired with low vision or blindness. Development of preventive measures is urgent.