Potential-Driven Electrochemical Clearing of Ex Vivo Alkaline Corneal Injuries

Abstract

Purpose Corneal chemical injuries (CCI) obscure vision by opacifying the cornea; however, current treatments may not fully restore clarity. Here, we investigated potential-driven electrochemical treatment (P-ECT) to restore clarity after alkaline-based CCI in ex vivo rabbit corneas and examined collagen fiber orientation changes using second harmonic generation (SHG). Methods NaOH was applied to the corneas of intact New Zealand white rabbit globes. P-ECT was performed on the opacified cornea while optical coherence tomography (OCT) imaging (∼35 frames per second) was simultaneously performed. SHG imaging evaluated collagen fiber structure before NaOH application and after P-ECT. Irrigation with water served as a control. Results P-ECT restored local optical clarity after NaOH exposure. OCT imaging shows both progression of NaOH injury and the restoration of clarity in real time. Analysis of SHG z-stack images show that collagen fibril orientation is similar between control, NaOH-damaged, and post-P-ECT corneas. NaOH-injured corneas flushed with water (15 minutes) show no restoration of clarity. Conclusions P-ECT may be a means to correct alkaline CCI. Collagen fibril orientation does not change after NaOH exposure or P-ECT, suggesting that no irreversible matrix level fiber changes occur. Further studies are required to determine the mechanism for corneal clearing and to ascertain the optimal electrical dosimetry parameters and electrode designs. Translational Relevance Our findings suggest that P-ECT is a potentially effective, low-cost treatment for alkaline CCI.

Electrochemical clearing of rabbit cornea post-acidic and alkaline injury

“…A series of three platinum electrodes was then placed over the globe as per previously described P-ECC protocol. 7 The working electrode is laid horizontally over the center of the cornea, the reference electrode rests over the outer edge of the cornea, and the counter electrode is placed near the bottom of the globe (Fig. 1).…”

“…Our group has previously described the suitability of a potential-driven electrochemical corneal clearing (P-ECC) system. 7 This system promotes the neutralization of chemical injury by producing a complementary acid-base reaction.…”