Each year, thousands of premature babies in intensive care nurseries lose their sight to retinopathy of prematurity (ROP), an eye disease which damages and detaches retina.
ROP began in 1940, and it is estimated that by 1953 ROP had blinded about 10,000 children, 7000 of these in the US (WA Silverman, “Retirolental fibroplasia: a modern parable” Monographs in Neonatalogy, NY: Grune & Stratton, 1980). More recently, a team of researchers at Baylor College of Medicine in Houston, Texas concluded that seven out of 10 premature babies develop some degree of ROP (Hosp Pract, 1984: 85-99). Even a baby born at term who is kept in hospital can develop ROP (Pediatrics, 1984; 73: 82-96).
My own son is one of the many children blinded by ROP, and it was his experience which led me to look into the causes of his eye damage.
This previously unknown disease began in the US a few years after the introduction of fluorescent lamps in the late 1930s.
The American Academy of Pediatrics recommends bright fluorescent lighting for neonatal intensive care nurseries, which in under 15 minutes exposes the retinae of babies to over nine times the US industrial safety regulation’s danger limit for healthy adult eyes.
It is beyond dispute that preemies are much more vulnerable than adult workers; that the clear preemie eye transmits more of the most damaging wavelengths than the age yellowed adult eye; and that the lamps used in hospital nurseries shine strongest in precisely the wavelength identified as inflicting the most retinal damage.
Dr Theodore L Terry, discoverer of the disease, argued from the beginning that excess light was the most logical cause (Arch Opthalmol 1943; 29: 54-68; JAMA 1945; 582-5). But some of his peers took a different view and set out to prove that oxygen supplements for preemies was the culprit. They held in 1953/54 a multi hospital trial, the Cooperative Study of Retrolental Fibroplasia (AMA Arch Opthamol, 1956; 56: 481-583).
The ethics of the study were highly questionable. Knowing that preemies with breathing problems die quickly if they don’t receive oxygen right away, the doctors withheld this essential help for the first two days from all babies enrolled in the study. As could be expected, this withholding killed off the preemies with the most immature lungs, who also happened to have the most immature eyes and were thus most at risk of developing ROP. Not surprisingly, the study found less eye damage among the survivors in the low oxygen group and immediately recommended curtailing supplementary oxygen for all preemies.
This study was instantly accepted as gospel, and oxygen was routinely restricted in intensive care nurseries. During the first and most severe decade of these restrictions, deaths from respiratory problems drove up the overall mortality among preemies in Baltimore by more than 60 per cent (J Ped, 1960; 57: 553-9). An analysis from England a few years later suggested that 16 babies died for every case of blindness “prevented” by oxygen restriction (Lancet, 1973; 2: 954-6; Lancet, 1974: 1:445-8). An extrapolation based on the increase of day of birth deaths quoted by Dr Silverman (cited above) suggests that action taken on the basis of this one study may have caused the deaths of 15,000 babies per year in the US alone more than twice as many Americans per year as the Vietnam war.
These restrictions placed on oxygen have now eased slightly, but the policy still harms many babies.
Many neonatologists assert that bright light is necessary so that they and the nurses can observe subtle colour changes in the skin of preemies. Skin colour is supposed to be a diagnostic sign for the baby’s degree of jaundice and for detecting low oxygen levels. Yet the Merck Manual of Diagnosis and Genetics (R Berkow Ed, Rahway, New Jersey: Merck & Co, 1982) says that “skin colour should not be trusted to evaluate the severity of jaundice.”
The “watch for colour changes” rationale for the bright nursery lighting creates a vicious circle. The bright light damages the eyes. The doctors blame the eye damage on excess oxygen, so they reduce oxygen to the point where the baby is kept right on the edge of turning dusky or blue from lack of oxygen. To see these colour changes, the nurse is said to need lots of light. That light damages the eyes of babies, and so on.
Some nurseries who have lowered their light levels report significantly lower levels of ROP. In most others, however, excessive light continues to burn the retinae of many babies and the unnecessary oxygen rationing policies deprive many of the oxygen that would help them escape cerebral palsy, other brain damage and, in some cases, death. Much suffering and many deaths of premature babies could be prevented by a flick of a light switch and a turn of an oxygen faucet.
!AH Peter Aleff
An engineer and researcher who has managed factories that protect workers from light damage.