[Measuring electrical impedance in normal and pathologic corneas].

Abstract

With a new technique the impedance of 89 normal and 7 severely damaged corneas was determined in vivo to look into the correlation between impedance and corneal cell damage. We found highly significant differences in impedance between normal and pathologically altered corneas. At 500 Hz frequency the impedance of normal corneas was 53.6 kOhm while the impedance of burned corneas only averaged 8.0 kOhm. There seems to be a correlation between the degree of pathological alteration of the corneal tissue and impedance as measured with this technique. The electrode head used allows fast, reproducible measurement of corneal impedance without any strain on the patient. Further studies must elucidate whether the method can be used as an early indicator of corneal damage before the onset of macroscopic change.