Light and the immature visual system

Abstract

SUMMARY Eye (1992) 6, 166-172This article is divided into three sections. First, the data on the neonatal light dose is summarised. Second, the mechanisms by which light may affect the eye will be con-.sidered and third, we mention clinical conditions in which light has been implicated as a factor. NEONATAL LIGHT DOSEThe amount of light reaching the eye is governed by two groups of factors. First, physical factors: the intensity, spectral characteristics, and duration of light exposure. The high dependency regions in four of the seven units were significantly brighter than their corresponding low dependency nurseries at all times. In two of these units there is a policy of reducing the level of artificial light in

Structural and functional consequences of bright light exposure on the retina of neonatal rats

“…Studies performed in adult albino cats and monkeys revealed that the maximum transmission of the eyelid was in the red spectrum while most of the blue light was stopped by the lids [41]. In humans, maximum transmission was also measured in the red portion of the light spectrum as a result of the filtering effect of the eyelids [42][43][44][45]. In humans, this red filter property did not appear to vary with age [42] and in fact, in human neonates, 38% of the white light was shown to be transmitted through the lids [43].…”

“…In humans, maximum transmission was also measured in the red portion of the light spectrum as a result of the filtering effect of the eyelids [42][43][44][45]. In humans, this red filter property did not appear to vary with age [42] and in fact, in human neonates, 38% of the white light was shown to be transmitted through the lids [43]. Based on the above estimate of the total amount of light transmitted through the closed eyelids (anywhere between 38% and 50%) and the use of an intense luminous environment (10,000 lux), we believe that there should have been enough light reaching the retina (3,800-5,000 lux) to cause significant damages to the retinal tissue.…”

Iluminación en unidades de cuidados intensivos neonatales: actualización y recomendaciones

“…Los neonatos más prematuros son visualmente más vulnerables: se fatigan con facilidad, tienen los párpados muy delgados y su inmadurez les impide cerrar los ojos consistentemente, por lo que son limitados sus recursos de protección frente a la luz. 37,38 Los cambios en la iluminación ambiental incluyen efectos transitorios: la disminución del nivel de iluminación produce una apertura inmediata y transitoria de los párpados, seguida de un período significativamente más largo cuando se mantiene esta menor iluminación. Los efectos publicados de la reducción de la luz en la UCIN son mayor estabilidad del neonato, estabilidad respiratoria, disminución de frecuencia cardíaca y respiratoria, presión arterial y actividad motora, menor tiempo en asistencia respiratoria y soporte de oxígeno.…”

Retinopathy of Prematurity: Clinic and Pathogenesis

“…Although oxygen supplementation has been recognized as a risk factor for the development of ROP since the 1950s, the relationship of oxygen to the development of ROP is complex and not completely understood [10]. Light has also been suggested as a possible risk factor for ROP [33,34,35] as well as many others [10]: absence of supplemental oxygen, apnea, mechanical ventilation, respiratory distress, parenteral nutrition, hyper- and hypocarbia, maternal bleeding, sepsis, home birth and many others.…”