Objective: To examine effects of long-term topical anti-glaucoma medications on meibomian gland morphology and function and assess their relationship with slit-lamp findings.
Methods: This was a cross-sectional observational case series of 31 patients with glaucoma (mean age ± standard deviation, 65.0 ± 13.0 years; mean duration of eye drop use, 7.9 ± 6.0 years) treated with topical anti-glaucoma drugs in only one eye for more than 1 year: 13 receiving prostaglandin analogues (PGs) alone, eight receiving β-blockers alone, and ten receiving multiple treatments. Untreated contralateral eyes served as controls. Lid margin (lid margin abnormality score: 0-4) and superficial punctate keratopathy (SPK score: 0-1) were observed with a slit lamp. Upper and lower eyelids were turned over to observe meibomian glands using non-contact meibography. Meibomian gland loss was scored for each eyelid from grade 0 (no loss of meibomian glands) through grade 3 (loss >2/3 of total meibomian gland area). Meibomian lipid content (meibum) was scored (meibum score: 0-3).
Results: Treated eyes had significantly higher scores for lid margin abnormality (P= 0.001), SPK (P< 0.001), meibo-score (P< 0.001), and meibum (P< 0.001) than control eyes. Tear film break-up time (BUT) was significantly shorter in treated eyes than in control eyes (P= 0.001). Schirmer values were significantly lower in treated eyes than in control eyes (P= 0.0039). Subgroup analysis indicated a significantly higher meibo-score in eyes treated with PGs (P= 0.0046) and in eyes treated with β-blockers (P= 0.0231) than in the corresponding controls.
Conclusions: Long-term anti-glaucoma eye drop use affects meibomian gland morphology and function.