Retrolental fibroplasia. Cases seen at the Helsinki University Eye Hospital 1956-1974.

In the period 1956-1974, 31 new cases of retrolental fibroplasia (RLF) were diagnosed at the Helsinki University Eye Hospital. All were alive in 1974. 90% weighed less than 1500 g at birth and the gestational age of less than 30 weeks at birth was present in 85%. All patients had required supplementary oxygen during the first weeks of life. 84% of the eyes had visual acuity of finger counting 1 m or less and when classified according to the corrected visual acuity in the better eye, 71% of the patients were practically blind according to the classification by Rintelen. 81% of the eyes showed one of the cicatricial stages of RLF, III to V, and 45% showed the grade V of the disease. 11% of the eyes showed corneal opacities, 44% a flat or absent anterior chamber, 11% had intraocular pressure of greater than or equal to 30 mmHg and 21% showed lenticular opacities. When the period of the observation was surveyed, it was found that during the latter half of the observation period, twice as many new cases of RLF were born. At a rough estimate it was calculated that in 1956-1974 at least 50 new cases of RLF developed in Finland.