Preservative-free latanoprost eye drops gentler on eyes

Preservative-free latanoprost eye drops induce a less severe stinging and burning sensation, leading to better adherence rates than its preserved counterpart, a recent study has found.

Researchers conducted a phase 4, parallel-group, investigator-blind, active-control, randomized trial including 51 patients with open-angle glaucoma or ocular hypertension. Twenty-six were given preserved latanoprost, while 25 received preservative-free eyedrops. Efficacy was assessed through corneal/conjunctival staining grade, Ocular Surface Disease Index (OSDI), and 12-week adherence, among other markers.

In the intention-to-treat (ITT) analysis, adherence rate improved in the preservative-free arm (3.72±21.88 percent), while it deteriorated in patients who received preserved eyedrops (–2.81±6.66 percent). The change values fell short of statistical significance.

However, in the per-protocol (PP) analysis, the differences in adherence change values were statistically significant in favour of preservative-free latanoprost (3.41±10.82 percent vs –2.92±6.77 percent; p=0.019).

In terms of secondary outcomes, the sum of bulbar and limbal hyperaemia scores was significantly lower in the preservative-free vs preserved arms, according to analysis of covariance both in the ITT (1.88±1.01 vs 2.46±1.24; p=0.049) and PP (0.86±0.64 vs 1.24±0.66; p=0.037) analyses.

“Preservative-free latanoprost shows better ocular tolerance assessed by hyperaemia scores and stinging and burning symptoms following higher adherence than preserved latanoprost in open-angle glaucoma or ocular hypertensive eyes,” said researchers.

“Close examination of the detrimental effect of benzalkonium chloride on the ocular surface should be verified by a long-term study design, since glaucoma medications are normally considered a chronic option,” they added.