Instruments for use in performing gel injection adjustable keratoplasty

Abstract

The present invention provides a surgical technique and instrument kit that allows for subtle modification of the corneal curvature by interlamellar injection of a synthetic gel at the corneal periphery while sparing the optical zone. The gel viscosity, volume and disposition within the surgical annular track as well as the diameter of the track, width, depth, and location are all parameters in the refractive change obtained. Following ultrasonic pachymetry performed centrally and at a selected wound entrance located about 2.5 to 3.5 mm from the apex, a one millimeter or so wide, about 75-85% corneal thickness depth radial incision is performed with a micrometric diamond knife adjusted to about 86% corneal thickness. Inserted through the partial-depth incision, a corkscrew-like dissector or helicoidal spatula forms a 360.degree. annular track centered about the apex. A transparent gel is manually injected through the incision, filling the annular channel. Using a surgical keratometer mounted to an operation microscope, the final corneal power is adjusted by massaging and removing the gel as necessary during the primary procedure or subsequent procedures, as the GIAK technique is reversible.