Electrochemical lysis of an intraocular tumour using a combination of electrode placements

The objective of this experimental study was to develop a new combination technique for electrode placement and the histomorphological evaluation of its effectiveness for the electrochemical lysis of large intraocular tumours.

The ECL was conducted on two freshly enucleated eyes containing large tumours, with maximal prominence of 11 and 12 mm and maximal base diameter of 16 and 19 mm, respectively. The ECL was carried out using an ECU-300 (Soring, Germany) apparatus generating an electrochemical charge of 30-35 K. In the course of the ECL procedure we used a new original combination technique of electrode placement, i.e., the anode was a surface electrode and the cathode was an intrastromal electrode. The anode had an original design.

A greyscale B-scan performed after the ECL completion showed decreased echogenicity and heterogeneity of the echo-structure of the tumour. According to the bioimpedancemetry data, the average duration of the ECL session was from 20 to 30 minutes depending on the tumour size. The results of pathomorphological examination performed after the ECL on two freshly enucleated eyes appeared to be similar. Thus, in both cases after lysis the eyeball did not change its size or shape. In both cases the tumour originated from the choroid plexus and showed subtotal necrosis. There was a pronounced boundary between the intact and electrochemically damaged tumour regions which attests to the local effect of the ECL restricted to the electrode placement area only.

The growing interest in the ECL procedure is due not only to its availability and low cost but mainly to its real clinical effect demonstrated in numerous publications. The absence of a developed ECL technology for the treatment of intraocular tumors, and, hence, reports on its clinical effectiveness, gave us the impetus to conduct this study. The proposed ECL method is promising and can be considered as optional for the organ-sparing treatment of large-sized intraocular tumours. Further optimization of the ECL parameters, as well as the development of sets of surface and intrastromal electrodes for different types of tumours, is required.