This study found that long-term antiglaucoma eye drop treatment was associated with alterations in meibomian gland morphology and function.
Subjects were 71 glaucoma patients receiving one type of antiglaucoma eye drops (group 1), 61 glaucoma patients receiving two types of antiglaucoma eye drops (group 2), and 30 glaucoma patients receiving three types of antiglaucoma eye drops, plus 75 healthy controls.
The authors used a questionnaire to evaluate subjective symptoms, slit-lamp examination to evaluate lid margin and superficial punctate keratopathy, and noncontact meibography (meiboscore) to assess upper and lower eyelid meibomian glands.
They found that lid margin abnormality, superficial punctate keratopathy, meiboscore, and meibum scores were significantly higher in glaucoma patients than in controls (P < 0.001). BUT and Schirmer scores were significantly lower in glaucoma patients than in controls (P < 0.001). Subgroup analysis revealed no significant difference between patients receiving prostaglandin and those receiving β-blockers.
Multivariate regression analysis demonstrated that meiboscore significantly correlated with lid margin abnormality score (P = 0.007) and BUT (P = 0.045) in group 1; with BUT (P = 0.004), symptom score (P = 0.003) and age (P = 0.026) in group 2; and with lid margin abnormality score (P = 0.001) in group 3.
The authors conclude that long-term use of antiglaucoma eye drops affects the morphology and function of the meibomian glands irrespective of the number or type of medications.
They say that the mechanism for meibomian gland loss in eyes with long-term use of antiglaucoma eye drops might be the result of chronic and subclinical inflammatory and allergic reactions causing lid margin abnormalities, followed by meibum stagnation, and resulting in changes in the meibomian glands that lie adjacent to the conjunctiva.
They say it is possible that both prostaglandins and β-blockers induced meibomian gland alterations. It is also possible that benzalkonium chloride (BAC), which is contained in most prostaglandin and β-blocker eye drops, contributed to the meibomian gland alterations.