Age-related morphological changes in lid margin and meibomian gland anatomy.
Meibomian gland dysfunction (MGD) is responsible for recurrent irritative symptoms. Attempts to characterize MGD have largely concentrated on microbial and lipid abnormalities in meibomian gland secretions. Few reports describe histological abnormalities in this disease, and fewer still morphological changes. This article follows a previous study that established a classification for MGD. This was based on morphological changes in the meibomian gland and lid margin. Using this classification, we studied the age-related changes in 80 subjects, between 5 and 87 years of age without ocular disease. The lid margin became thicker after childhood. Lid margin vascularity and cutaneous hyperkeratinization increased with age in both lids, whereas, telangiectasia increased with age in the lower lid and squamous blepharitis and posterior lid margin rounding were more common after 50 years of age in the upper lid. Multiple rows of meibomian gland orifices occurred more frequently in the upper than lower lid, and orifice narrowing and pouting increased with age. No age-related changes in the shape or form of the mucocutaneous function, gland ducts, or acini were found. Meibomian gland secretions were less easily expressed in the elderly. We have attempted to define a normal range of lid morphology in healthy children and adults that we believe to be important for the subsequent definition of lid disease, and in particular, posterior blepharitis.