Allopurinol and Hypothermia Can Revive Ischemic Pig Eye for mfERG Study

Abstract

Abstract: : Purpose: To develop the isolated arterially perfused pig eye as an in vitro model for studying retinal physiology using multifocal electroretinography (mfERG). Methods: Fresh pig eyes collected from an abattoir were cannulated through the ophthalmic artery and perfused with Krebs' solution. The ERG was recorded using the VERIS 1.0 (Visual Evoked Response Imaging System). Effects of allopurinol and hypothermia on the mfERG were tested.. Results: Allopurinol at concentrations of 250mg/L and 500mg/L significantly increased the revival rate of ischemic pig eyes as judged by reproducible mfERG responses for at least 4 hours. Moderate hypothermia of 28.5°C and 30.5°C significantly increased P1 and N1 amplitudes compared to those of 32.5°C. P1 and N1 implicit times at 28.5°C were significantly longer than those at 30.5°C and 32.5°C. Conclusions: Allopurinol and moderate hypothermia can revive pig eyes from total ischemia. Allopurinol concentration of 250mg/L and moderate hypothermia of 30°C were found to be appropriate conditions to combat reperfusion injury in pig eyes. Both P1 and N1 amplitudes and P1 implicit times were found to be sensitive to retinal perturbation and hence could be considered as reliable indices of retinal physiology. The pig eye collected from an abattoir offers a viable in vitro model for retinal electrophysiological studies.

Keywords: retina