Laser assisted robotic surgery in keratoplasty

Abstract

Purpose : To develop a robotic platform for laser induced welding of the corneal tissue in keratoplasty, supporting or substituting standard suturing.

Methods : The robotic console has been designed accordingly to the ophthalmic surgical requirements. It consists of an "end effector" that enables to release the laser light on the surgical cut area with micrometric precision and with adjusting speed. The system is able to recognize the target, previously stained with Indocyanine Green. The device also provides for the on board integration of a robot vision system, able to monitor the induced thermal effect on the tissue and to control the surgical scene.
The system has been tested in 10 freshly enucleated porcine eyes. A penetrating circular cut was performed in each eye using the 8.0 mm diameter Burron trephine. The surgical cut was stained in depth with a water solution of Indocyanine Green. The compact laser (810 nm, 1W) used for welding is controlled and moved by the robotic arm and delivery of the laser light is guaranteed in correspondence of the stained wound.

Results : The robotic console was able to deliver the laser light in a controlled and circular pattern. Accidental movements of the patient's eye are compansated by the laser pattern control system. The on board thermal camera evidenced the temperature dynamics on the external cornea surface, in the range of effective welding (temperature enhancement of 15°C). Full information on the surgical scene are reported on a PC: by doing this, the surgeon can verify the efficacy of the treatment and make real-time decisions.
Histology of the treated tissues evidenced the welding of the stroma in depth.

Conclusions : The proposed robotic laser system proves to have the necessary characteristics to induce an effective welding of corneal tissue that is independent from the operator. This can thus be used to support or to substitute standard suturing with needle and stitches in keratoplasty.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

The sketch of the end effector for laser assisted robotic welding