Severe retinopathy of prematurity and visual outcomes in British Columbia: a 10-year analysis.

Objective: To describe the incidence trend and long-term visual outcomes of infants diagnosed with stages 3 to 4 retinopathy of prematurity (ROP) or laser-treated ROP born in British Columbia (Canada).
Study Design: Data from all (n=1384) neonates with birth weight (BW) <1250 g, admitted to British Columbia Children's Hospital between period 1 (January 1992 to December 1996) and period 2 (January 1997 to December 2001) were analyzed. Ophthalmologic records of infants with stages 3 to 4 ROP or laser-treated ROP were abstracted. chi(2)- and t-test were used to compare neonatal characteristics between periods. Logistic regression was used to identify risk factors associated with visual impairment (defined as visual acuity <or=20/60 or visual field restriction of 20 degrees binocularly).
Result: Of 1159 surviving infants, 887 were examined for acute ROP (473 in period 1, 414 in period 2). Stages 3 to 4 ROP or laser-treated ROP were present in 35 infants in period 1 (7%) and 59 in period 2 (14%), P<or=0001. Infants born in period 2 had lower mean BW and gestational age. Among infants who developed severe ROP or laser-treated ROP, binocular visual impairment was present in eight children in period 1 and seven in period 2. Refractive errors, including myopia and astigmatism, were increased in period 2. Children who developed periventricular leucomalacia had the highest risk of visual impairment at 4 to 6 years of age.
Conclusion: During the 10-year study period, a significant increase in rates of stages 3 to 4 or laser-treated ROP was not associated with increases in visual impairment rates.