A Surgical Guidance System for Big-Bubble Deep Anterior Lamellar Keratoplasty

Deep Anterior Lamellar Keratoplasty using Big-Bubble technique (BB-DALK) is a delicate and complex surgical procedure with a multitude of benefits over Penetrating Keratoplasty (PKP). Yet the steep learning curve and challenges associated with BB-DALK prevents it from becoming the standard procedure for keratoplasty. Optical Coherence Tomography (OCT) aids surgeons to carry out BB-DALK in a shorter time with a higher success rate but also brings complications of its own such as image occlusion by the instrument, the constant need to reposition and added distraction. This work presents a novel real-time guidance system for BB-DALK which is practically a complete tool for smooth execution of the procedure. The guidance system comprises of modified 3D+t OCT acquisitions, advanced visualization, tracking of corneal layers and providing depth information using Augmented Reality. The system is tested by an ophthalmic surgeon performing BB-DALK on several ex vivo pig eyes. Results from multiple evaluations show a maximum tracking error of 8.8 micrometers.