However, even with cryotherapy, about 400-600 infants with ROP become legally blind each year. More recently, laser therapy also has been utilized in addition to cryotherapy. Unfortunately, a sizeable minority of patients still have vision loss. Lighting in hospital nurseries is generally similar to typical office fluorescent lighting. Although there is no specific lighting standard, routine lighting in nurseries can vary considerably within and between nurseries.
Some nurseries periodically keep the lighting at a lower level, especially at night.
Researchers used specialized goggles for the study because simply turning down the lights in the nursery is not a reliable method of light reduction for an individual infant. Also, babies in nurseries can be exposed to a variety of light sources, such as sunlight or reflected light from another baby undergoing light therapy for jaundice. The Light-ROP study carefully monitored the actual light levels in nurseries. None of the infants involved in the study were exposed to any increase or reduction in nursery lighting beyond that found in a standard hospital nursery. Apart from the goggles, infants in both groups received the same medical care.