Retrolental fibroplasia: a study of the incidence and aetiological factors, 1977-1979.
Between July, 1977, and December, 1979, a total of 699 babies was screened in special care nurseries for retrolental fibroplasia (RLF). Changes were found in 46 babies (6.6%): in 25 of these, RLF reached only Stage I or Stage II of the Keith classification, and later regressed completely. The remaining 21 reached Stage III or higher and in 25% the condition progressed to permanent visual damage. Retrolental fibroplasia did not occur in babies whose highest PaO2 did not exceed 10.7 kPa (80 mmHg), and in babies who had less then three days of oxygen therapy. It did not reach Stage III in babies who weighed more than 1600 g at birth or were of more than 32 weeks' gestation. Girls were significantly more affected than boys. This study supports the strict correlation of RLF with prematurity and oxygen therapy; we found retrolental fibroplasia only in the very small and very premature infants, and visual damage only occurred in approximately 5% of these.