Retrolental fibroplasia--controlled study of 4 years' experience in a neonatal intensive care unit.

During the 4 years 1977-80, 14 infants developed retrolental fibroplasia (RLF) in the neonatal unit at this medical centre. All were very low birthweight (VLBW) infants who weighed 1500 g or less at birth. The incidence of RLF was 3.5% for all VLBW infants admitted for neonatal intensive care and 4.7% for VLBW survivors. The mean birthweight of the affected infants was 970 (range 730-1310) g and mean gestational age 26 (range 24-29) weeks. Seven of the affected infants (2.4% of VLBW survivors) had significant scarring with temporal dragging of the optic disc and retinal detachment. Each of the 14 infants was matched with 2 control infants in order to see whether any factors predisposing to the development of RLF, including those related to oxygen therapy and monitoring, could be identified. The only factor associated with RLF was a higher volume of blood given with replacement transfusions. The occurrence of RLF was unrelated to an increase in requirement for or duration of oxygen therapy, arterial oxygen tensions as determined by intermittent sampling, or the availability of transcutaneous oxygen monitoring. The care taken in oxygen therapy may have been responsible for failure to show a quantitative association between hyperoxaemia and RLF. Although the problem of oxygen therapy in preterm infants is far from being resolved, current neonatal intensive care methods have limited the occurrence of RLF to VLBW infants. This study demonstrated a lower incidence of RLF in VLBW infants despite an improved survival rate compared with that previously reported.