[Dielectric behavior of the rabbit cornea as a measure of the healing process in injured epithelium].
To correlate changes in the passive electrical properties of the rabbit cornea with quantitative grading of corneal injuries induced by topical application of 70% ethanol, we measured ocular tissue impedances using a surface electrode over the range of 10(4)-10(8) Hz and followed their temporal changes for up to 17 days. Dielectric measurements on control eyes yielded a broad dispersion curve, which, in loss tangent terms, could be decomposed into two components: dispersion 1 on the low-frequency side and dispersion 2 on the high-frequency side. By defining the peak value of the total dispersion as Pt and those of subdispersions 1 and 2 as P1 and P2, the ratios, P1/Pt and P2/Pt, were found to serve as useful indices. Upon appearance of corneal erosion due to ethanol, P1/Pt markedly increased and returned to the control level with re-epithelialization of the cornea, and the time course of P2/Pt showed a mirror image to that of P1/Pt. Both ratios correlated well with the erosion area determined photographically. These results indicate that dielectric spectroscopy is applicable to the assessment of the extent and severity of corneal injury.
Mokudai
Y
Y
Department of Ophthalmology, Kochi Medical School, Japan.
Watanabe
M
M
Ando
M
M
Ueno
H
H
D000818:Animals; D003315:Cornea / Q000473:pathology / Q000503:physiopathology*; D004594:Electrophysiology; D004848:Epithelium / Q000473:pathology; D011817:Rabbits; D014945:Wound Healing