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.