Growth of meibomian gland tissue after intraductal meibomian gland probing in patients with obstructive meibomian gland dysfunction

PURPOSE: To investigate the impact of meibomian gland probing (MGP) on meibomian gland (MG) area from the upper lids of patients with obstructive meibomian gland dysfunction (o-MGD). METHODS: Retrospective study comparing pre-MGP/post-MGP non-contact infrared meibography results in patients with o-MGD, viewing signs of MG growth within total measurement field. RESULTS: Post-MGP meibography of 34 lids (19 patients, ≥4.5 to ≤12 months’ follow-up) showed 41.2% with MG growth. Ten lids had meibographies suitable for analysis, showing significant collective (116 glands) increase in mean individual glandular area (MIGA) of 4.87% (p=0.0145). Four of 10 lids independently showed significant increase in MIGA, ranging from 10.70% to 21.13% (p<0.0001, p=0.0277, p=0.0292, p=0.0345), while six did not. At >12 and <25 months’ follow-up, 16 lids (9 additional patients) had follow-up showing 25% with signs of MG growth. Analysis of three lids showed a significant collective (33 glands) increase in MIGA of 11.19% (p=0.0004). Two of three lids independently showed significant increase in MIGA of 13.73% and 20.00% (p=0.0097, p=0.0001). Collectively, for all 13 analysed lids (149 glands), there was a significant increase of 6.38% in total glandular area (p=0.0447) and a significant increase of 6.23% in MIGA (p=0.0003). CONCLUSION: MGP was associated with increased MG tissue area and growth of atrophied MGs as viewed on meibography. MGP provides unequivocal physical proof of a patent meibum outflow tract through the natural orifice, and may promote glandular growth in part by direct mechanical establishment of a patent duct/orifice system.