Objective ocular surface tolerance in patients with glaucoma treated with topical preserved or unpreserved...

Preservatives in glaucoma medications have been associated with ocular toxicity. We compared ocular signs and symptoms in patients with open-angle glaucoma or ocular hypertension treated in monotherapy with preserved or preservative-free prostaglandin analogues.

Observational cross-sectional clinical study in real life. 82 patients treated for at least 6 months with prostaglandin analogue were assessed for intraocular pressure, ocular symptoms and ocular signs including conjunctival hyperaemia, tear break-up time and tear meniscus height measured using objective and non-invasive methods (OCULUS Keratograph 5M). Patients presenting with symptoms of ocular toxicity with preserved prostaglandin analogues were switched to preservative-free latanoprost, and a second assessment was processed 6 months after.

At inclusion, 30 (36.6%) patients were treated with preservative-free latanoprost, 25 (30.5%) with preserved latanoprost, 16 (19.5%) with preserved travoprost and 11 (13.4%) with preserved bimatoprost. Patients treated with preservative-free latanoprost reported significantly less ocular symptoms upon instillation (mainly burning) and between instillations than patients treated with preserved prostaglandin analogues. The mean conjunctival hyperaemia (limbal + bulbar) was significantly lower with preservative-free latanoprost (2.08 ± 0.55) compared to preserved latanoprost (2.50 ± 0.7, p = 0.0085), preserved travoprost (2.67 ± 0.82, p = 0.0083) and preserved bimatoprost (2.68 ± 0.67, p = 0.0041). There were no relevant between-group differences in mean tear meniscus height and break-up time. Ocular symptoms and conjunctival hyperaemia improved when preserved prostaglandin analogues were switched to preservative-free latanoprost for 6 months while intraocular pressure reduction was maintained.

Overall, this study suggests a better subjective and objective ocular tolerance when patients were treated with preservative-free latanoprost than with other preserved prostaglandin analogues monotherapy. Switching to preservative-free latanoprost maintained intraocular pressure at the same level as preservative prostaglandin analogue, but improved ocular surface tolerance.