Sir.—Premature infants are subjected to stringent invasive and noninvasive oxygen monitoring in the pursuit of the elusive "safe" path between hypoxic brain damage on the one hand and increased risks of blindness from retinopathy of prematurity (ROP) on the other. For the majority of infants, this period is relatively short. In some infants, however, chronic lung disease leads to such a prolonged oxygen requirement that home oxygen administration is considered. Hudak et al1 have recently reported a growth benefit to 30 infants receiving oxygen at home when their pulse oximetry was kept over 95% saturation. They also stressed avoidance of hyperoxia but did not relate this to the degree of retinal immaturity or ROP present in a particular infant.
The risk for severe ROP appears to be proportional to the degree of retinal immaturity, ie, the amount of avascular retina. It follows from this understanding that when the