Key points are not available for this paper at this time.
IN view of the present controversy centring in the role of oxygen in the aetiology of retrolental fibroplasia, we have thought it essential to investigate the influence of varying concentrations of oxygen upon the immature retina. Since it is now well established that the earliest stages of this disease are angioblastic in nature and present as an overgrowth of the developing retinal vessels, it was necessary to select a laboratory animal in which the anatomy and embryology of the retinal vessels were comparable with those in man. In the cat, embryo vascular budding commences at the disc between the 35th and 45th day of intra-uterine life, but the vessels do not reach the retinal periphery until about 3 weeks after birth, whereas, in man, the retinal vasculature is complete at birth. The degree of retinal vascularization in the full-term kitten at birth and in the ensuing 3 weeks is therefore com- parable in extent to that in the premature baby. Since, with minor variations, the retinal vascular development is in all other respects very similar to that in man, the kitten appeared to be ideal for our purpose.
Ashton et al. (1953) studied this question.