VISUAL OUTCOME IN PRETERM INFANTS ANALYSIS OF PRETERM INFANTS BORN IN LJUBLJANA 1990–1999

Abstract

Background. Improved perinatal care has increased the survival rate of prematurely born infants. An epidemiological fact that 6–18% and more visually impaired children were prematurely born, emphasises the effect of premature birth on both visual function and development. Despite better knowledge on retinopathy of prematurity (ROP) it is stressed not to underestimate refractive errors, strabismus and visual impairment after brain lesions, being more common in preterm babies. Methods. Over 1300 preterm infants with a birth weight of 1500 g or less and gestational age of 30 weeks or less, born in Maternity Hospital of Ljubljana, Slovenia in the period 1990– 1999 were examined according to contemporary paediatricophthalmologic recommendations. At least one year ophthalmologic follow-up (average 3.5 years) of 594 prematurely born infants with high neonatal risk factors for ROP and with general health problems, was performed. Sex, gestational age, birth weight, artificial ventilation, exchange blood transfusion, bronchopulmonary dysplasia, respiratory distress syndrome, apnoea, septicaemia, intraventricular haemorrhage, hyperbilirubinemia were analysed for correlation with ROP and visual impairment. Results. The survival rate of the studied preterm infants was 65–87% (mean 77.3%). ROP stage 1, 2 has developed in 33 children with a birth weight under 900 g and in 10 with a birth weight 900–1200 g (altogether in 8%). ROP stage 3–5 has been registered (with or without plus disease) in 7 children (below 6%). In 6 children cryo or argon laser photocoagulation has been performed and vitreoretinal surgery in 1 child (without functional results). In the studied group altogether 4 children (below 1%) became blind (visual acuity < 0.05), all of them have had septicaemia. Squint has been registered in 6.9% of children, and has correlated with higher refractive error, mostly myopia. Severe optic nerve atrophy has been noticed already in the first year of follow-up in 2% of children, causing visual loss ≤ 0.3. Low gestational age, need for artificial ventilation, septicaemia and at least one exchange transfusion have shown a significant correlation with ROP. Severe asphyxia has been present in 1.4% of the children, severe intraventricular haemorrhage (grade III-IV) in 5.1%, and periventricular leucomalacia in 4.1% of the examined children. Their association with ROP has not been significant, but these variables seem to influence strongly the postretinal visual development. Conclusions. ROP in children born in the Ljubljana region doesn’t seem to be an epidemiological problem, however it is the responsibility of paediatric ophthalmologists to organise screening and therapy programmes for ROP and to follow up the preterm infants’ visual development, with a special attention to increasing postretinal visual impairment, refractive errors and amblyopia.