The retinopathy of prematurity.

When the condition of retrolental fibroplasia was first described by Terry (1942) in the United States of America it was then only recognized in the advanced state of a cicatricial mass or membrane behind the lens. It is now appreciated, however, that the earliest pathological changes occur in the nerve fibre layer of the retina, which first of all becomes thickened as a result of oedema, transudation and haemorrhage then follow, with subsequent neovascularization and invasion of the vitreous. In cases which do not regress the process ultimately goes on to fibrosis, with detachment of the retina and the formation of a retrolental membrane. In 1950 Heath therefore suggested that the process could best be described as a retinopathy of premature birth. The first case to be recorded in Edinburgh was in 1948, one more case occurring in that year, four being recorded in 1949, four in 1950, and eight in 1951. In 1952 we began an examination of premature infants born in the City of Edinburgh.