Mokudai Y, Watanabe M, Ando M, Ueno H
Department of Ophthalmology, Kochi Medical School, Japan.
Nippon Ganka Gakkai Zasshi. 1994 Mar;98(3):215-23.
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.
为了将兔角膜的被动电学性质变化与局部应用70%乙醇所致角膜损伤的定量分级相关联，我们使用表面电极在10(4)-10(8)Hz范围内测量了眼组织阻抗，并跟踪其长达17天的时间变化。对对照眼的介电测量产生了一条宽分散曲线，就损耗角正切而言，该曲线可分解为两个成分：低频侧的分散1和高频侧的分散2。通过将总分散的峰值定义为Pt，将子分散1和2的峰值定义为P1和P2，发现比率P1/Pt和P2/Pt可作为有用的指标。由于乙醇导致角膜糜烂出现时，P1/Pt显著增加，并随着角膜重新上皮化恢复到对照水平，P2/Pt的时间进程与P1/Pt呈镜像关系。这两个比率与通过摄影确定的糜烂面积密切相关。这些结果表明，介电谱适用于评估角膜损伤的程度和严重性。
