Effects of Preservative on the Meibomian Gland in Glaucoma Patients Treated with Prostaglandin Analogues

This study compared the effect of preservative-containing (PC) and preservative-free (PF) prostaglandin analogue (PGA) formulations on the ocular surface, especially on the meibomian gland (MG) in patients with open-angle glaucoma (OAG). This is a retrospective study of treatment-naïve patients with OAG (n=80) and healthy controls (n=40). OAG patients were randomized into groups using either PC-PGA or PF-PGA for 12 months. All participants underwent ocular surface and MG examinations including their meibum score, meiboscore, and lid margin abnormality score (LAS). Eighty OAG patients were randomized into two groups (n=42 in PC, n=38 in PF). All PGA and control groups showed similar ocular surface and MG parameters at the baseline. Both PC- and PF-PGA groups showed increased meibum scores, meiboscores, and LASs at 12 months compared to the baseline (all p<0.05). At the 12-months visit, PC-PGA group showed severe OSDI, shorter TBUT, greater OSS, and worse MG parameters than those of the other two groups (all p<0.05). In addition, PF-PGA group showed worse meiboscores, meibum scores, and severe OSS scores than those of the control group (all p<0.05). Both PC and PF formulations can cause damage to the MG in patients using PGA. However, PC formulations induced more ocular discomfort, poorer ocular surface, and more severe MG loss compared to PF formulations. Therefore, it would be advisable to use PF formulations in patients with a preexisting or concomitant ocular surface disease or MGD.