The introduction of retinal lazer surgery (RLS) for stage 3+ retinopathy of prematurity (ROP) has dramatically reduced the number of babies blinded by ROP leaving our neonatal unit since 1991.

We compared development at 8 months corrected chronological age of 23 extremely short gestational age infants (birthweight 783, range 530-1335g; gestation 25.5, range 23-30 weeks) who required Retinal Lazer Surgery for Stage 3+ Retinopathy of Prematurity (ROP) with 23 controls (birthweight 784, range 570-1160g; gestation 25.5, range 23-30weeks) matched for gestation, sex and date of birth. Paired controls were selected, blind to specific identifiers and outcomes, as the survivor of the same gestational age and sex with the closest birthday to each index case. Patients who were functionally blind were excluded. There were 5 boys and 18 girls in each group born between 1991 and 1996. Developmental outcome measures included Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) of the Bayley Scales of Infant Development, Movement Assessment of Infants (MAI) and 5 age-appropriate vision-dependent developmental test items. The significance of the differences of the two groups (paired data) was assessed using paired t-test and Wilcoxon signed rank test for vision dependent test items. Cases scored significantly lower than controls on MDI (78.0 vs 92.9, mean difference 14.8, 95%CI 5.0-24.6, p=0.005) but PDI scores were not significantly different (75.4 vs 84.7, p=0.2). On the MAI, motor risk scores were significantly higher in the cases (18.7 vs 10.2, mean difference 8.6, 95%CI 16.0-1.3, p=0.02) suggesting increased risk for later neuromotor problems. On the 5 vision dependent test items ranked as pass or fail, cases scored significantly fewer passes than controls (p=0.002) suggesting subtle visual developmental difficulties.

Although vision was preserved in this population at high risk of blindness from ROP, we found poorer performance on visually related test items at 8 months compared to controls. Furthermore, our results suggest that this sub-set of infants have a higher incidence of other subtle neuromotor developmental problems.