Increase of macular pigment optical density with age in premature infants measured by fundus reflectometry

Abstract

Purpose : The macular pigment consists of carotenoids taken up into the eye from the diet. Infants get their carotenoids from maternal blood via the placenta before birth. In the present study, we investigated macular pigment optical density (MPOD) levels in 44 Japanese prematurely born infants.

Methods : The infants were admitted to the Department of Neonatology, Seirei Hamamatsu General Hospital. Fundus images of the macula were taken using a RetCam3^® instrument (Clarity Medical Systems, Pleasanton, CA) with blue light excitation at 484 nm. MPOD levels were calculated by comparing average maximum pixel intensity levels, I_max, at 7 degrees eccentricity, with average minimum pixel intensity levels, I_min, in the center of the macula. Our study had IRB approval from Seirei Hamamatsu General Hospital; written informed consent was obtained from the parents.

Results : The corrected age of the infants ranged from 23 weeks to 38 weeks; 21 infants were male, and 23 were female. Images with sufficient image contrast, i.e. differences between I_max and I_min could be obtained in infants with age of 33 weeks and more, but not in infants with age of less than 33 weeks. RetCam3^® images were captured at two or more age points in all but 8 infants. Three infants could not be measured at any age.
MPOD levels ranged between 0 and 0.22 optical density units (mean = 0.09, SD = 0.04). Results with all infants are drawn in the attached plot, showing an increase of MPOD levels with age in all cases after the threshold age of 33 weeks (Fig.1). The mean MPOD levels every week increased linearly (Fig.2). At any age, infants showed an inter-subject variation in MPOD levels from 1.2 to 6.5 folds (median=2.3 fold).

Conclusions : Significant MPOD levels could be detected for the first time in prematurely born infants after they had reached a threshold age of 33 weeks, and the increase of MPOD levels could be tracked over time. These results offer the opportunity to investigate the role of maternal and infant diets in future studies with prematurely born infants as well as term infants.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Fig.1

 

Fig2