A bipolar coaxial microprobe for safe transvitreal diathermy.

We present a new 22-gauge transvitreal bipolar diathermy microprobe. With the use of the coaxial principle, the current flows only at the probe's end surfaces. Because of its small size and end-on coagulation effect, and when used in conjunction with a low-frequency diathermy unit, the probe can be used safely on vessels lying directly on the retinal surface and close to the optic nerve head. We report three cases to demonstrate the usefulness of this instrument.