## 2 Materials and Methods
### High-Frequency Diathermic Probe  
The high-frequency diathermic probe (abee(r) Glaucoma Tip, Oertli Instrumente AG, Berneck, Switzerland) consists of an inner and outer coaxial electrode. Both electrodes are isolated, while the inner one is made by platinum.  
The dimensions of platinum probe tips are 1 mm in length, 0.3 mm high, and 0.6 mm wide. The platinum probe tip is bent posteriorly at an angle of 150\({}^{\circ}\). The probe external diameter is 0.9 mm. Electrical current is modulated at MF (-500 kHz) frequency. The temperature of approximately 130 \({}^{\circ}\)at the tip of the probe is generated by alternating current, while target tissue temperature ranges from 90\({}^{\circ}\) to 100\({}^{\circ}\). The tissue is heated by radio frequency-induced intracellular oscillation of ionized molecules, which leads to elevation of intracellular temperature. The very high temperatures cause breakdown of tissue molecules. Inhomogeneous electric field with high voltage and selective current flow conduct to electric arcs (Figure 1).  
Bearing in mind that the vaporization or cutting process is the best accomplished with relatively low voltage, the coagulation is performed by arcing modulated high-voltage current to tissue. The electric arcs create cell bursts through the evaporation of cell content. By modulating the voltage, it is possible to cut and at the same time make locale coagulation. There is a galvanic separation between the power source and the surgery hand piece (Figure 2).  
First, the electrodes are placed away from the tissue, and then the gap between two electrodes is ionized. Due to ionization process, an electric arc discharge develops. In this approach, tissue burning is more superficial because the current is spread over the tissue area more than over the tip of electrode. The experimental set-up provides high-frequency power dissipation in the vicinity of the tip. This was demonstrated in the histological analysis by showing that there is more of a cutting effect in the tissue than coagulation, because there is no tissue nor cell denaturation in the cutting channel and surrounding tissue (Figure 3).  
Figure 1: Inhomogeneous electric field, high voltage, and electric arc.  
Figure 2: High-frequency (HF) generator.  
Two clear corneal incisions were used: one of 1.2-mm tempora  
Figure 3: Histological analysis of a high-frequency deep sclerotomy (HFDS) cut (HE staining, human eye).  
The electric specifications of the probe remained unchanged. Pockets were created with the probe 1 mm through the trabecular meshwork, into Schlemm canal. The target was the insertion of a pocket of 1 mm into the sclera. The target deep sclerotomy pocket is approximatively 0.3 mm thick and 0.6 mm wide, resulting in a resorption surface area of 3.6 mm\({}^{2}\) (Figure 5a).  
For comparison, it is shown a normal anterior chamber and angle anterior (Figure 5b).  
The tip's dimensions and ab interno approach make it compatible with the stipulations of minimally invasive glaucoma surgery.  
Statistical analysis: statistical calculation was done with SPSS Program Version 22. Two-tailed student t-test was used for statistical evaluation of parametric data. Significance was set at a \(p\) value of \(<\)0.05.