Light reduction and the electroretinogram of preterm infants

Abstract

Aims-To examine the eVects of light on retinal development and function in preterm infants as measured by the electroretinogram (ERG). Secondary outcomes included visual acuity testing, the incidence of retinopathy of prematurity, and general wellbeing, reflected in feeding tolerance, rate of weight gain, and length of hospital stay. Methods-Eligibility criteria for enrolment were birthweight < 1250 g and gestational age < 31 weeks. Sixty one infants were randomly allocated by 6 hours after birth to a control or treatment group which wore 97% light filtering goggles for a minimum of four weeks or until the infant reached 31 weeks postmenstrual age. Results-There were no significant diVerences between the two groups in the numbers of electroretinograms performed at 36 weeks of postmenstrual age. Although the sample size was not large enough to exclude clinically important diVerences in secondary outcomes, no significant diVerences were observed between the groups in visual acuity testing at 4-6 months corrected age, incidence of retinopathy of prematurity, weight gain, or length of stay. Conclusion-These data support the safety and feasibility of this intervention. A much larger study will be needed to determine whether light reduction to the eyes of very low birthweight infants will reduce the incidence of retinopathy of prematurity or enhance general wellbeing.

The Effects of Creating an Artificial Night on the Pattern of Weight Gain Among Preterm Neonates

“…Nonetheless, Boo et al (2002) found that premature neonates' exposure to cyclical twelve-hour lighting or continuous darkness did not significantly affect their weight gain (3). The results of studies by Kennedy et al (1997) and Mirmiran et al (2003) also illustrated that environmental lighting had no significant effect on neonates' weight gain (2,11).…”

“…A probable explanation for such contrary findings may be the differences in the gestational and the postnatal ages of the participants of these two studies. Besides, Kennedy et al (1997) used eye covers for the neonates in their target group, which might have been stressful for their participating neonates (11).…”

Does reducing light exposure decrease the incidence of retinopathy of prematurity in premature infants?

“…Of the studies included in the Cochrane review, three were also included in the present review (9)(10)(11). These studies (LOE 1) were RCTs in which the eyes of babies in the treatment groups were covered continuously from no more than 24 h after birth until 31 to 35 weeks' corrected gestational age, while control groups were exposed to normal NICU lighting.…”

“…All three studies used the International Classification of ROP system. Seiberth et al (9) randomly assigned 127 infants with birth weight <1501 g and gestational age at birth ≤32 weeks, and Kennedy et al (10) randomly assigned 61 infants with birth weights <1251 g and ≤31 weeks' gestational age at birth, while the Light Reduction in Retinopathy of Prematurity (LIGHT-ROP) study by Reynolds et al (11) enrolled a total of 409 infants of birth weight <1251 g and gestational age at birth <31 weeks. Each study concluded that there was no statistically significant difference in the incidence of ROP between the two groups.…”

“…Both Seiberth et al (9) and Reynolds et al (11) ensured that the ophthalmologists were masked to the group assignment, and confirmed the diagnosis of ROP by performing at least two consecutive examinations. Two studies neutral to the clinical question (10,14) were of fair quality. In the study by Kennedy et al (10), the incidence of ROP was a secondary outcome, while Braz et al (14) did not give any details with regard to the ocular protection, nor was there any reference to whether ophthalmologists were blinded to the group assignments.…”