A Novel In Vivo Corneal Trans-epithelial Electrical Resistance Measurement Device

Abstract

Purpose: : To develop a device capable of measuring corneal trans-epithelial electrical resistance (TER) and changes in the corneal barrier function in a rabbit corneal epithelial defect model.

Methods: : Methods: The shape of the corneal TER measuring device was designed for clinical use. The device contained a small sensor composed of corneal and conjunctival electrodes covered with conductive gel. The sensor was designed so that it could be fixed to the Goldman applanation tonometer mounted on a slit lamp. Corneal TER was measured in anesthetized New Zealand white rabbits (n = 3-6) using a sensor and a volt-ohm meter (EVOMX). Subsequently, an 8-mm-diameter corneal epithelial defect was made using n-heptanol, with the TER measured immediately after making the epithelial defect and on days 1, 3, and 7.

Results: : Measurements of the corneal TER were made within a 5-s period by gently touching the sensor to the ocular surface. Immediately after making the corneal epithelial defect, the corneal TER decreased to 6.4 +/- 3.1% of the initial value. The corneal defect decreased on days 1 and 3, with the TER improving to 10.8 +/- 4.0% and 80.0 +/- 41.6%, respectively. By day 7, the corneal defect had disappeared, and the TER value had increased to 119.4 +/- 4.3%.

Conclusions: : Development of a new corneal TER measurement device made it possible to quantify the amount of improvement of the corneal barrier function in a corneal epithelial defect model in rabbits. In the future, this new device may be applicable for clinical use in humans.

Keywords: cornea: epithelium • electrophysiology: non-clinical • wound healing