PURPOSE: To compare meibomian gland morphology between children and adults. DESIGN: Cross-sectional, observational case series. METHODS: In an institutional setting, healthy pediatric (n = 78, 30 boys, 48 girls; mean age standard deviation, 4.1 +/- 3.4 years; range 1 month - 12 years) and adult (n = 25, 11 men, 14 women; 31.3 +/- 4.8 years; range 24-39 years) volunteers participated in the study. A noninvasive mobile pen-shaped infrared meibography device was used to observe the meibomian glands. Lost meibomian gland area (meiboscore) was scored from grade 0 (no meibomian gland loss) through grade 3 ( > two-thirds of the total area lost). The number of meibomian glands in each eyelid was counted by reviewing the video. Eyelid width was measured using a ruler. Meibomian gland density was calculated as the number of meibomian glands divided by the eyelid width. RESULTS: The numbers of meibomian glands in the upper/lower eyelids were 26.9 +/- 3.9 / 22.0 +/- 2.2 in the pediatric group and 28.1 +/- 2.7 / 24.4 +/- 2.6 in the adult group (P = .22, P < .0001). Eyelid width was 24.4 +/- 2.4 mm in the pediatric group and 27.9 +/- 1.57 mm in the adult group (P < .0001). Meibomian gland densities in the upper/lower eyelids were 1.09 +/- 0.17 / 0.91 +/- 0.11 in the pediatric group and 1.01 +/- 0.12 / 0.88 +/- 0.10 in the adult group (P = .03, P = .45). CONCLUSIONS: The mobile pen-shaped infrared meibography device is useful for obtaining information on the meibomian gland structure, not only in adults but also in children, including infants. The morphology of the meibomian glands in children was the same as that in adults, distributing across the whole tarsal plates in both the upper and lower eyelids. (c) 2013 by Elsevier Inc. All rights reserved.