Evaluation of Age-related Changes in Human Palpebral Conjunctiva and Meibomian Glands by In Vivo Confocal Microscopy

PURPOSE:To investigate the age-related changes in human palpebral conjunctiva and meibomian glands by in vivo confocal microscopy. METHODS:Forty-nine healthy volunteers (20 men and 29 women; mean age, 43.4 ± 22.7 years; range, 9-85 years) were recruited from the community. Laser scanning confocal microscopy was used to observe and measure the upper palpebral conjunctiva and meibomian glands. Customized software was used to analyze the images. The quantitative parameters included the mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units. RESULTS:Mean densities of goblet cells, conjunctival basal epithelium, Langerhans cells, and meibomian glandular acinar units were 1050 ± 495 cells per square millimeter, 2979 ± 510 cells per square millimeter, 32 ± 16 cells per square millimeter, and 71 ± 27 glands per square millimeter in total subjects, respectively. No statistically significant difference in these 4 parameters was observed between the male and female subjects. Significant negative correlations were noted between age and goblet cell density (r = −0.646; P < 0.0001) and meibomian glandular acinar unit density (r = −0.585; P < 0.0001). However, no significant correlation was detected between the densities of conjunctival basal epithelium or Langerhans cell density and age. CONCLUSIONS:Age-related changes under laser scanning confocal microscopy included decreased densities of goblet cells in human palpebral conjunctiva and the acinar units in meibomian glands.