Comparison of corneal and conjunctival changes after dosing of travoprost preserved with sofZia, latanoprost with 0.02% benzalkonium chloride, and preservative-free artificial tears.

PURPOSE: To evaluate corneal and conjunctival changes after chronic, once-daily dosing of travoprost preserved with sofZia, latanoprost preserved with 0.02% benzalkonium chloride (BAK), or preservative-free artificial tears.

METHODS: Thirty New Zealand white rabbits were randomized to receive once-daily instillation of travoprost with sofZia, latanoprost, or preservative-free artificial tears in 1 eye. Corneal epithelial changes were evaluated by transmission electron microscopy and graded on a standard scale by 2 masked observers. Conjunctival inflammation was evaluated by light microscopy after hematoxylin and eosin staining. Lymphocytes were counted in the epithelium and superficial stroma by 2 masked observers and compared among groups.

RESULTS: Corneal tissue treated with preservative-free artificial tears and travoprost with sofZia revealed similar changes under transmission electron microscopy (P = 0.53). Significantly more corneal epithelial damage was noted with latanoprost than travoprost with sofZia (P = 0.0001). The number of lymphocytes in the conjunctival epithelium and stroma was significantly lower in eyes treated with travoprost with sofZia than eyes treated with latanoprost (P = 0.0001). The number of conjunctival lymphocytes was similar among conjunctival specimens exposed to travoprost with sofZia and preservative-free artificial tears (P = 0.65).

CONCLUSIONS: Once-daily dosing of travoprost with sofZia produced significantly fewer corneal changes and less conjunctival inflammation than latanoprost preserved with BAK. Corneal and conjunctival changes noted with travoprost with sofZia were similar to those induced by preservative-free artificial tears. Glaucoma medication with high levels of BAK may cause more deleterious effects on the ocular surface than non-BAK-preserved medications. Human studies are needed to better understand the clinical effects of different preservative types and concentrations on the ocular surface.