The Ocular Surface in Medically Controlled Glaucoma: An In Vivo Confocal Study

Area of Science:

• Ophthalmology
• Confocal Microscopy
• Ocular Surface Disease

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Medical management of POAG often involves long-term topical ocular medications.
• Ocular surface disease is a common complication of glaucoma treatment.

Purpose of the Study:

• To investigate ocular surface findings using clinical examination and in vivo laser scanning confocal microscopy (LSCM) in patients with stable, medically controlled primary open-angle glaucoma (MCPOAG).
• To assess the impact of anti-glaucoma medications on the ocular surface in MCPOAG patients without a history of dry eye.

Main Methods:

• Recruited 100 MCPOAG patients and 50 healthy controls.
• Excluded participants with a history of dry eye prior to glaucoma diagnosis.
• Performed clinical and LSCM examinations of the ocular surface.

Main Results:

• MCPOAG patients exhibited increased subbasal nerve length, tortuosity, and dendritic cell density compared to controls, with no overt clinical abnormalities.
• Preserved medications correlated with reduced tear film breakup time and Schirmer test values.
• Increased lissamine green conjunctival staining and decreased Schirmer test values were observed with multiple medications and higher drop frequency.
• LSCM revealed subbasal changes associated with preservatives, drug type, and number of eye drops.

Conclusions:

• Ocular surface changes in stable MCPOAG patients on anti-glaucoma medications are predominantly subclinical.
• Active ingredients, preservatives, drug combinations, and instillation frequency contribute to ocular surface alterations.
• The clinical significance of these medication-induced ocular surface changes requires further investigation.