Classification of Techniques in Refractive Surgery

2.4.1 Surgical Terms Following Waring's Classification

Waring classified refractive surgical techniques due to their similarities in surgery. Before developing a classification which follows the intention of change, Waring's approach will be used to become familiar with the terms commonly used in Refractive Surgery.

2.4.1.1 Lamellar Refractive Surgery

Early Keratomileusis: "Freeze and Grind It"
Epikeratoplasty: "Cap It"
Keratophakia: "Sandwich It"

This class is characterised by slicing the cornea in different horizontal layers and treating some of them to change the overall refraction. These techniques usually follow the "thickness law" thoroughly investigated by J.I. Barraquer. Corneal tissue can be replaced, added or subtracted. Techniques subtracting tissue have shown best results and are called keratomileusis. A short explanation of some of lamellar techniques will be given in the following historical round up. Lamellar techniques in theoretical terms seem very promising, as they directly change the shape of the cornea and do not depend on indirect biostatical effects. Anyhow, in the past, they were not widely used, due to their complicated surgical procedure and high surgeon's learning curve. With laser application, it seems to be that in the future, LASIK will overcome all former non lamellar techniques. The surgical procedure is maybe not so easy as in superficial PRK that it can be done by every average ophthalmologist, but it is still very straight forward.