Real-time intraocular antiglaucoma drugs measurement in porcine eyes using boron-doped diamond microelectrodes.

Abstract

The primary treatment for glaucoma, the leading cause of intermediate vision impairment, involves administering ocular hypotensive drugs in topical eye drops. Observation of the real-time changes in the drugs through the cornea and reaching the anterior chamber is essential to improve or develop a safe, reliable, and effective medical treatment. Conventional methods such as LC-MS/MS are used to measure the temporal changes in the drug in the aqueous humor; however, this technique involves multiple measurements of the eyes of multiple test subjects to measure changes over time with high temporal resolution. To resolve this problem, we develop a measurement method that utilizes boron-doped diamond (BDD) microelectrodes to track the real-time drug concentrations in the anterior chamber of the eye. First, we optimize the method for continuously measuring timolol maleate (TIM), a sympathetic beta-receptor antagonist, and obtain the calibration curves of each BDD microelectrode in the aqueous humor collected from porcine eyes. Next, we demonstrate the continuous ex vivo monitoring of the TIM in the enucleated porcine eyes. The results suggest that changes in the intracameral TIM concentration can be monitored using BDD microelectrodes.