THE EFFECT OF RAISED INSPIRED CARBON-DIOXIDE ON NORMAL RETINAL VASCULAR DEVELOPMENT IN THE NEONATAL RAT

Purpose. Raised arterial carbon dioxide levels have been suggested as a risk factor for retinopathy of prematurity (ROP). We investigated th e effect of raised Inspired CO? on normal postnatal vasculogenesis in the neonatal fat retina.Methods. One hundred fifty newborn rat pups we re divided among 15 mothers (n = 10 for each litter). Five litters wer e exposed to low CO2 (0.2%), 5 litters exposed to 6%, and 5 litters to 10% CO2. On day 7 of life the rats were sacrificed and the total reti nal and vascularized retinal areas analyzed. Results. The vascularized retinal area and ratio of vascularized to total retinal area were red uced in rats exposed to 6% and 10% CO2. Conclusions. Raised inspired C O2 was associated with retardation of normal retinal vascular developm ent and increased peripheral avascular area in neonatal rats. Raised C O2 may be a risk factor for the development of abnormal neovasculariza tion such as in ROP.