Effects of antiglaucoma drugs on the ocular surface in rabbits: a fixed-combination drug versus two concomitant drugs

Area of Science:

• Ophthalmology
• Ocular Surface Disease
• Pharmacology

Background:

• Glaucoma treatment often involves topical medications.
• Long-term use of antiglaucoma drugs can lead to ocular surface changes.
• Preservatives in eye drops are a potential cause of ocular surface toxicity.

Purpose of the Study:

• To compare the ocular surface effects of a fixed-combination antiglaucoma drug versus two concomitant antiglaucoma drugs.
• To evaluate the impact of different glaucoma medication regimens on conjunctival cytology and histology.

Main Methods:

• Twenty-four rabbits were divided into four groups: timolol, travoprost, fixed-combination travoprost/timolol, and concomitant timolol and travoprost.
• Conjunctival impression cytology was performed at baseline and weeks 1, 3, and 6.
• Conjunctival biopsy was performed at week 6.

Main Results:

• No significant differences in ocular surface cytology were observed among the timolol, travoprost, and fixed-combination groups.
• The fixed-combination group showed statistically significant differences compared to the concomitant group at week 6.
• Biopsies revealed normal conjunctival epithelium in groups 1-3, while group 4 exhibited reduced epithelial cell layers and fewer goblet cells.

Conclusions:

• Fixed-combination antiglaucoma drugs appear to be beneficial in minimizing adverse ocular surface changes during long-term use.
• The reduced preservative concentration in fixed-combination formulations is hypothesized to contribute to better ocular surface tolerability.
• This suggests a potential advantage of fixed-combination therapies for patients requiring long-term glaucoma management.