Effects of polyquaternium- and benzalkonium-chloride-preserved travoprost on ocular surfaces: an impression cytology...

To compare the toxicity effect of polyquaternium (PQ) and benzalkonium chloride (BAK) preservation of travoprost on the ocular surface.

This prospective study included 44 eyes of 44 patients with newly diagnosed glaucoma. Twenty-two patients used PQ-preserved travoprost (PQ group) and 22 patients used BAK-preserved travoprost (BAK group). To investigate the effect on the ocular surface, conjunctival impression cytology (IC) was performed at baseline and the 1- and 6-month follow-up visits. Additionally, the ocular surface disease index (OSDI) questionnaire, Schirmer I test, and tear break-up time (TBUT) measurement were administered at baseline, and at 1-, 3-, and 6-month follow-up visits.

While both groups showed statistically significant IC grade increases at 1 and 6 months when compared with baseline measurements, IC grades were significantly higher for patients using PQ-preserved travoprost compared with patients using BAK-preserved travoprost. The Schirmer I test and TBUT scores were not statistically significant between group 1 and BAK group at baseline and at 1-, 3-, and 6-month visits (P>0.05). OSDI scores did not statistically differ at baseline and the 1-month measurements between the 2 groups (P>0.05), but the 3- and 6-month OSDI scores were significantly higher for BAK group (P=0.001). Differences in OSDI and Schirmer I test scores were statistically significant at 1, 3, and 6 months in both groups as compared with baseline values (P<0.05). Statistically significant differences in the TBUT scores were seen for both groups at 3 and 6 months, while BAK group, but not PQ group, had insignificant score differences at 1 month as compared with baseline values of PQ group (P=0.083).

PQ-preserved travoprost was found to be safer and better-tolerated than BAK-preserved travoprost. PQ-preserved travoprost provided better ocular surface comfort, and therefore a better patient experience, which would likely result in higher treatment compliance.