Assessment of corneal epithelial integrity after acute exposure to ocular hypotensive agents preserved with and without benzalkonium chloride.
The corneal toxicity of 2 intraocular pressure-lowering agents was compared in a rabbit cornea model with New Zealand White rabbits. Corneal epithelial morphology and cell size were assessed by in vivo confocal microscopy. Baseline microscopic examinations were performed on 1 eye of each animal. Two weeks later, the eyes were bathed for 3 min in travoprost 0.004% preserved without benzalkonium chloride (BAK( or latanoprost 0.005% preserved with 0.02% BAK; the eyes were then rinsed with balanced salt solution, and the corneas were again examined by confocal microscopy (n=4/group). A second group of animals was exposed to the medications through a dosing regimen of 1 drop/min (lpar3 drops total) (n=4/group). In eyes treated with travoprost without BAK (3-min bath), superficial epithelial cells were similar to baseline, as indicated by their visible cell borders and bright nuclei. In contrast, the surface cells in eyes treated with latanoprost were significantly smaller and brighter and had less distinct borders. Surface cell size was significantly smaller as compared with baseline size and as compared with rabbits treated with travoprost without BAK for 3 min. Similar effects on corneal epithelial cell morphology were observed with the 1-drop/min dosing regimen. In this rabbit model, travoprost 0.004% preserved without BAK did not cause corneal epithelial toxicity; latanoprost 0.005% induced superficial cell loss, most likely caused by the presence of a relatively high concentration of BAK (0.02%).
Whitson
Jess T
JT
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9057, USA.
Cavanagh
H Dwight
HD
Lakshman
Neema
N
Petroll
W Matthew
WM
D000287:Administration, Topical; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001548:Benzalkonium Compounds; D003008:Cloprostenol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D019573:Epithelium, Corneal / Q000473:pathology*; D000077338:Latanoprost; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage / Q000009:adverse effects*; D011817:Rabbits; D000069557:Travoprost
D000959:Antihypertensive Agents; D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D011461:Prostaglandins F, Synthetic; D003008:Cloprostenol; D000077338:Latanoprost; D000069557:Travoprost