Retinopathy of prematurity: Causes, prevention and treatment

Retinopathy of prematurity (ROP) is a proliferative disorder of the immature retinal vasculature. The retina has no blood vessels until around 16 weeks' gestation; the vessels grow out from the optic disc and only reach the periphery of the eye 1 month after birth (Kanski, 2011). ROP was recognised in 1942 in Boston, USA, by Theodore L Terry, and was initially named retrolental fibroplasia. It was described as a ‘fibroplastic overgrowth of persistent vascular sheath behind each crystalline lens’ (Fleck and McIntosh, 2008: 84). While Terry identified ‘fibroblastic overgrowth’, he did not identify the specific aetiological connection to oxygen. Further research, undertaken by Dr Patz in the 1950s in Washington DC, showed that premature infants now cared for in closed cots/incubators, who received high concentrations of oxygen in a confined space, were more likely to develop ROP than those who received low levels. This discovery resulted in oxygen levels administered to preterm infants being restricted to a maximum of 40%, which resulted in increased levels of morbidity and mortality. Thus, the importance of adequate oxygenation with careful monitoring of blood gas measurement and saturation monitoring was seen as the way forward in preventing ROP.