In prevention of retrolental fibroplasia, the oxygen should be: (AIIMS May 2012)
1. Retrolental fibroplasia or retinopathy of prematurity (ROP) is a bilateral retinal disease seen in premature infants due to excessive oxygenation during 1st few weeks of life.
2. A high concentration of oxygen leads Q to spasm of the retinal vessels Hypoxia occurs followed by vascular dilatation and neovascularization in the periphery of retina.
3. Progressive neovascularization leads to vitreous hemorrhage and localized retinal detachment.
4. The contraction of fibrovascular tissue ultimately results in total detachment of retina which lies as a white mass behind the lens, causing leukocoria and blindness.
5. Main differential diagnosis is retinoblastoma in which there is usually no history of prematurity and oxygen therapy.
6. Oxygen concentration of 30% is considered to be safe.