IMPACT OF GLAUCOMA EYEDROPS ON OCULAR SURFACE AND MEIBOMIAN GLAND FUNCTION

Glaucoma is a chronic and progressive disease where intraocular pressure (IOP) is the only modifiable risk factor. Previous studies reported that long-term use of glaucoma drops leads to ocular surface disease which compromises treatment compliance and outcomes of filtration surgery. Ocular surface damage can be accessed with tests like TBUT and corneal staining however they can be normal in early disease. Corneal epithelial thickness (CET) can provide information of ocular surface disease even in early stages, and it can be access by using anterior segment optical coherence tomography (AS-OCT). Also important in ocular surface evaluation is the meibomian gland function, accessed by lipid layer thickness (LLT). Taken it into account we aim to access the impact of long-term use of anti-glaucomatous drops on ocular surface integrity and meibomian gland function.

Cross-sectional observational case series including glaucoma patients treated with lowering pressure eye drops for at least 12 months. Duration of therapy, number of drugs, active principle and preservative presence were noted. Controls comprised healthy patients. Dry eye disease (DED) diagnostic criteria included symptoms by OSDI questionnaire and signs (TBUT and corneal fluorescein score (CFS).  LLT was accessed by interferometry with LipiView® interferometer. CET was measured with AS-OCT (Cirrus HD-OCT). Statistical significance was set at p<0.05.

40 patients treated with lowering-IOP drops were included in our study. There was no difference in age between groups (p>0.05). Eyes treated with anti-glaucomatous drops had higher proportion of DED diagnosis, with higher OSDI and CFS scores and lower TBUT (p=0.03). LLT was lower in treated patients (p=0,02). LLT was inversely correlated with number of glaucoma drops, but the difference was not statistically significant. The central CET was lower in treated patients. Patients treated with preservative-containing topical medications had lowest CET (p=0.03).

Glaucoma drops negatively affected ocular surface and meibomian gland function. Lubricant drops with lipid composition should be added to glaucoma therapy to minimize dry eye signs and symptoms in these patients. Preservative-free drops might be a preferable treatment option to decrease glaucoma eyedrops impact in ocular surface.