Technique for the selective heating of corneal stroma

Conventional thermokeratoplasty, which relies upon thermal conduction from the epithelium into the stroma, does not generate a desirable temperature profile through the cornea. Previous reports show that temperature levels in the epithelium and in Bowman's membrane are excessive, often resulting in damage to these structures. In addition, this study shows that when corneal thickness exceeds approximately 300 microns, the central portion of the stroma probably will not reach critical shrinkage temperature. Shrinkage only in the superficial stroma may result in minimal and transitory alterations of corneal shape. Variation in treatment results may also occur due to the difficulty in precise control of treatment duration. An alternative corneal heating technique is discussed which appears to solve these three basic problems.