Estrogen receptor expression in meibomian glands and its correlation with age and dry-eye parameters

Purpose: To investigate the correlation between estrogen receptor-positive basal cells of the meibomian glands of the lower lid with age, gender, and subjective and objective dry-eye parameters. Methods: Sixteen lower lid specimens were collected from 7 female and 9 male patients ( age range 22 88 years) during tumor surgery requiring whole-thickness excision. Prior to surgery the patients were asked about any dry-eye symptoms (score 0 - 4, where 0= no dry-eye symptoms). Tear break-up time was measured, and Schirmer I and II tests were performed. We obtained histological sections from the outer margins of the formalin-fixed and paraffin-embedded specimens and performed immunohistochemical staining for estrogen, progesterone and androgen receptors. At least 500 cells were counted per specimen, and the proportion of positively stained cells was calculated and correlated to the age and dry-eye parameters. Results: All meibomian glands had positive nuclear staining with antibodies for estrogen receptors in their outer cell layers, i.e., the basal cell layer. The proportion of cells expressing estrogen receptors increased with age independent of gender ( correlation coefficient= 0.67, P< 0.005). No correlation was found between estrogen receptor positivity and subjective dry-eye symptoms, tear break-up time, or Schirmer I and II test results. There was no difference in the proportion of cells expressing estrogen receptors between female and male patients (P= 0.5). Conclusions: The amount of meibomian gland cells expressing estrogen receptors in the lower lid seems to increase with age independent of gender and seems not to affect the fat layer and stability of the tear film.