Breakdown evaluation of corneal epithelial barrier caused by antiallergic eyedrops using an electrophysiologic method.
OBJECTIVE
The aim of this study was to examine the usefulness of an electrophysiologic method for predicting corneal epithelial breakdown by antiallergic eyedrops and comparing the results with those in other appraisal methods.


METHODS
Six kinds of antiallergic eyedrops, including benzalkonium chloride (BK) as an ophthalmic preservative and two kinds of BK-free antiallergic eyedrops, were used in this study. Eyedrops were applied to excise rabbit corneas and monitoring was performed according to an electrophysiologic method, using a commercially available chamber system to mimic human tear turnover. Changes in transepithelial electrical resistance (TEER) in the corneal surface were recorded. The cytotoxicity of each kind of eyedrops in a normal rabbit corneal epithelial (NRCE) cell line and a human endothelial cell line EA.hy926 was also examined.


RESULTS
The extent of decrease in the corneal TEER after applying antiallergic eyedrops was dependent on the concentration of the BK included as a preservative, but it was also affected by the different kinds of drugs when the BK concentration was low. Higher cytotoxicity of the eyedrops against the NRCE and EA.hy926 cell lines was observed with a reduction of TEER.


CONCLUSIONS
Monitoring changes in the corneal TEER, according to the electrophysiologic method with the application of antiallergic eyedrops, is useful for predicting corneal epithelial breakdown caused by their instillation.
Nakashima
Mikiro
M
Department of Clinical Pharmacy, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. mikirou@nagasaki-u.ac.jp
Nakamura
Tadahiro
T
Teshima
Mugen
M
To
Hideto
H
Uematsu
Masafumi
M
Kitaoka
Takashi
T
Taniyama
Kotaro
K
Nishida
Koyo
K
Nakamura
Junzo
J
Sasaki
Hitoshi
H
D000818:Animals; D018926:Anti-Allergic Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D001548:Benzalkonium Compounds / Q000494:pharmacology; D001813:Blood-Retinal Barrier / Q000187:drug effects*; D002460:Cell Line; D002626:Chemistry, Pharmaceutical; D015194:Diffusion Chambers, Culture; D017097:Electric Impedance; D004594:Electrophysiology; D019573:Epithelium, Corneal / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D011817:Rabbits
D018926:Anti-Allergic Agents; D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical