Effects of osmoprotection on symptoms, ocular surface damage, and tear film modifications caused by glaucoma therapy

To determine the effects of 2 artificial tear formulas on the ocular surface in patients with glaucoma using topical preserved beta-blockers (BB) or prostaglandins (PG).

This was a prospective, comparative, randomized, double-blind study with a crossover design. Twenty patients with dry eye were divided into 2 groups based on glaucoma treatment: BB (10 subjects) or PG (10 subjects). Each group was administered a 4-week course of unpreserved isotonic (300 mOsm/L) solution containing 0.2% sodium hyaluronate (SH) or a preserved isotonic (295-305 mOsm/L) solution containing 0.5% carboxymethylcellulose and 0.9% glycerin as compatible solute (CMCs) administered QID. After a 2-week washout period, the course of treatment was reversed. The primary efficacy criteria consisted of assessing symptoms according to the Ocular Surface Disease Index© (OSDI); the secondary efficacy criteria consisted of evaluating tear film confocal microscopy, central corneal thickness (CCT), and lissamine corneal and conjunctival staining (Oxford Grading System Score [OGSS]).

Within each group, only CMCs induced a significant improvement in OSDI and OGSS compared to baseline values: OSDI -20.5, p<0.0001; OGSS -0.9, p<0.0001. Tear film confocal microscopy improved after treatment, especially in case of patients who were administered CMCs. No difference in CCT was noticed for any subject.

This study demonstrates for the first time that the use of concomitant CMCs in the management of glaucoma undergoing treatment with BB or PG may assist in tear film production and could lead to better compliance with intraocular pressure-lowering medication and ultimately better prognosis.