Active guidance for laser retinal surgery with a handheld instrument.

Laser photocoagulation is a standard interventional tool in vitreoretinal surgery. Commonly applied treatments such as grid photocoagulation and panretinal photocoagulation involve the application of hundreds of dot-like laser burns to the retina. In order to enhance the accuracy and reduce the tedium of this procedure, we are developing a robot-assisted technique for retinal laser photocoagulation that includes software for planning patterns of laser burns on a retinal image and uses an active handheld micromanipulator known as Micron in order to apply the pattern of burns to the retina. The paper describes the system and presents preliminary results. In a sample 7x7 pattern of lesions applied to an artificial surface, the system demonstrated a mean position error of 43+/-23 microm.