Analysis of Meibum before and after Intraductal Meibomian Gland Probing in Eyes with Obstructive Meibomian Gland Dysfunction

Purpose: To evaluate whether the amount of meibum and its viscosity change after intraductal meibomian gland probing in patients with refractory obstructive meibomian gland dysfunction (o-MGD). Methods: Six lid margins of 3 patients with refractory o-MGD underwent intraductal meibomian gland probing. Meibum and the clinical outcome were evaluated before the procedure and at a 1-month postoperative visit. Meibum was quantified with a Meibometer, and its viscosity (Shimazaki grade) was assessed simultaneously. The tear film condition was evaluated by lipid layer interferometry (DR1, Kowa, Nagoya, Japan), and meibomian gland loss was analyzed by noncontact infrared meibography. Lid margin findings, tear break-up time, fluorescein score, and ocular symptoms were also assessed. Results: At the postoperative visits, all cases showed improvements in meibum lipid levels (446-1376, 757-802, and 396-571 meibometer units) and meibum viscosity (grade 3-0, 3-1, and 3-2). Two cases showed an improvement in tear break-up time (2-5 and 0-6 seconds). No morphological changes in the meibomian gland were observed in any cases. Conclusions: Intraductal meibomian gland probing seems to improve meibomian gland lipid levels, and it may be a good treatment option for cases of o-MGD that are resistant to conventional treatment.