Abstract
Purpose:
We have identified in the mouse a light-response pathway via melanopsin stimulation that regulates the formation of retinal vasculature during a period that approximates the first trimester of gestation in humans. We were thus interested as to whether average day length (ADL) during early gestation was a predictor of severe ROP (SROP).
Methods:
Institutional review board approval for this study was obtained. 712 eyes of 357 premature infants (401-1250 g birth weight (BW)) from 1998 to 2003 were included. Multiple logistic regression with generalized estimating equations to account for inter-eye correlation was performed. The outcome variable SROP was (1) classic threshold ROP in zone I or zone II, (2) type 1 zone I ROP, or (3) in a few eyes, type 1 ROP in posterior zone II that examiners chose to treat.
Results:
Multiple logistic regression analysis evaluating all 712 eyes with 76 eyes developing SROP showed that BW, gestational age, per capita income in the zipcode area of the mother’s residence, multiple birth, black race, and ADL were independent predictors of eyes developing SROP. Each additional hour of ADL during the first 90 days after the estimated date of conception (EDC), decreased the likelihood of SROP by 29% (p = 0.014). In a model of 146 prethreshold ROP eyes with 76 eyes developing SROP, each additional hour of ADL during the first 105 days after EDC decreased the likelihood of SROP by 46% (p = 0.001).
Conclusions:
The finding that longer average day length during early gestation lowers the risk for severe ROP supports the finding in fetal mice of a light-response pathway that regulates the formation of retinal vasculature and may have implications for light during early gestation as a prophylactic treatment to prevent severe ROP.
Keywords: 706 retinopathy of prematurity •
464 clinical (human) or epidemiologic studies: risk factor assessment