Classification of Techniques in Refractive Surgery

2.4 Classification of Techniques

Many kinds of techniques have been developed in Refractive Corneal Surgery with the aim of correcting myopia, astigmatism and sometimes even hyperopia. Most techniques brought best results in correcting pure myopia. Firstly, flattening the cornea seems to be somewhat easier than steepening the cornea or adding tissue to it. Secondly, there are more myopic than hyperopic patients. However, it needs to be mentioned that in no circumstance is the cause of the refractive disease cured by corneal surgery, only their refractive symptoms are taken away. Is very likely that neglecting the additional side effects of the applied procedure, "regression" will occur in corrected myopic eyes as the myopic disease is not stopped by the surgical adjustment of the cornea. Nevertheless, on the long term, when technology will be fully mastered, hyperopic correction might even be more stable than myopic correction.

There have been various approaches in classifying refractive surgical procedures, such as following the historical development, sticking to similarities in the surgical procedure or following surgical intention of change. The first approach following the historical development does not seem to be very systematic. However, knowing the historical development in detail can help to optimise future developments, by learning from past experiences, checking old results either being fundamentally true or only limited to the techniques of those times.