Retinal Neovascularisation in Newborn Rats Submitted to Variations of Concentrations of Oxygene. Histopatological Aspects

Abstract

This study was conducted on two groups of newborn rats: a control group and an experimental group. The control group and was composed of seven newborn rats, which were placed at 4 hours after birth, in a pediatric incubator, together with their mother, in conditions of normoxia for 21 days. The experimental group consisted of seven newborn rats, which were placed at 4 hours after birth, in a pediatric incubator with their mother, in conditions of normoxia for 7 days, then five days in a daily alternating periods of hyperoxia (80%) and hypoxia (10%), and then nine days in conditions of normoxia. Slaughtering of the rats was performed on day 21 and the eyeglobes were harvested in order to perform histopathological examinations. Microscopic examination revealed a normal development of the retina in the control group. In the experimental group, on the surface of the retina, an exaggerated neovascularization both respects the number of vessels, as well as their size was observed. Excessive proliferation of blood vessels caused severe histo-architectural changes, irreversible and bilateral, with serious damage of the retinal function.