488
THE
JOURNAL
OF PEDIATRICS
O X Y G E N AND R E T R O L E N T A L F I B R O P L A S I A N AN editorial discussion in the Janexposed in the incubator is related to u a r y issue (page 122) of the experi- the development of retrolental fibromental work of Ashton and his co- plasia. I n these experiments length of workers, linking oxygen with the de- exposure is indicated as a factor. velopment of retrolental fibroplasia, it F r o m their clinical and experiwas noted that other as yet unreported mental, data, Patz and his co-workers experimental studies were in progress. feel that certain recommendations in In a recent issue of the America~n Jourthe care of the premature infant are nal of Ophthalmology, P a t z / E a s t h a m , justifiable---the practice of rigid curHigginbotham, and Klek 1 r e p o r t on extailment of oxygen t h e r a p y for the perimental studies using newborn premature i n f a n t ; an accurate oxygen white rats and mice. In one of their analyzer' as standard n u r s e r y equipexperiments, litters of rats were exment, with frequent sampling of the posed to an oxygen concentration of 80 oxygen tension of the incubator; the per cent, while control litters were ordering of oxygen by concentration maintained in a concentration of 20.8 r a t h e r t h a n the rate of flow, and the per cent. A t the end of twenty-one days, use of oxygen in the nursery only on 12 of 27 rats exposed to the high con,specific order, except in case of emercentration showed vascular changes gency. These are in line with the and edema in 17 eyes, while no changes recommendations r e f e r r e d to in the were detected in 58 eyes of the control group of 29 animals. In another ex- previous editorial. The importance of retrolental flbroperiment, litters of white mice were exposed to the high concentration for plasia as a cause of blindness in the preschool child is stressed in a recent periods of seven, fourteen, and twentyreport of the National Society for the one days, with control litters of similar size exposed to a low concentration. Prevention of Blindness. Blindness in I n a group of 36 mice exposed for this group increased 47 per cent beseven days there were 21 abnormal t w e e n 1943 and 1950. Most of this eyes, while none were found in the increase was due to retrolental fibrocontrol group. A f t e r fourteen days of plasia. Between these two dates blindexposure, 41 abnormal eyes were found ness f r o m prenatal influences decreased f r o m 12.9 cases per 100,000 in 34 animals, and 2 in the control children to 8.5; blindness from infecgroup of 33. The number of abnormal eyes rose to 71 in 38 animals exposed tions decreased from 2 to 1; blindness for twenty-one days, while none were from injuries fell from 1.1 to 0.6; but found in 37 control animals. The blindness due to retrolental fibroplasia changes were chiefly capillary prolifer- increased from 1.4 to 10.9. Over 95 per cent of the blindness in preschool ation and hemorrhage, " s t r i k i n g l y similar to the changes detected in hu- children takes place before the infant is a year old. man retrolental fibroplasia." Thus evidence continues to accumuREFERENCE late that the oxygen concentration to I. IJatz~ Eastham, IIigginbotham, and Klek: which the small premature infant is Am. J. Ophth. 36: 1511, 1953.
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