Meibomian Gland Probing Stimulates a Proliferative Epithelial Response Resulting in Duct Regeneration.

PURPOSE: To demonstrate that the meibomian gland ductal basement membrane and basal epithelial cell layer are in continuity with and may derive from lid margin orifice-associated rete ridge epithelial/basement membrane structures (OARREBS) and to characterize changes in the distal duct microanatomy after meibomian gland probing (MGP) using in vivo confocal microscopy (IVCM).

PATIENTS AND METHODS: Pre/post-MGP IVCM examinations were performed on upper lids. Thirty-six identical glands from 20 lids of 16 patients (49.24 ±17.11 y/o with 13:3 F:M) were identified, analyzed, and compared to control cases. Statistical analyses were performed using ImageJ software and IBM SPSS version 27. All MGPs were performed within 12 weeks of the initial examination. Post-MGP follow-up exams occurred at 5.03 ±4.48 months.

RESULTS: Post-MGP images showed more superficially organized OARREBS with accelerated and more superficial basement membrane formation, and an average increase of 32.2%, 25.4%, 32.04%, 77.7%, and 81.3% in duct wall epithelial cell layers (DWECL) (p < 0.001, compared to control (CTC) p < 0.001), distal duct wall thickness (DWT) (p < 0.001, CTC p < 0.001), proximal DWT (p < 0.001, CTC p < 0.001), distal lumen area (p < 0.001, CTC p = 0.037), and proximal lumen area (p < 0.001, CTC p = 0.007), respectively. The increase in the distal DWT and lumen area correlated with the months of follow-up (p = 0.004 and p = 0.010, respectively). Immediate post-MGP imaging revealed the probe track confined to the ductal epithelial compartment.

CONCLUSION: MGP appears to stimulate a proliferative epithelial response characterized by an accelerated more superficial formation of ductal basement membrane with increased DWECL as well as DWT and lumen area at two separate duct foci. These findings suggest activation of lid margin meibomian gland precursor cells and confirm that MGP stimulates an epithelial regenerative phenomenon, not a fibrotic one.