One thing that you need to realize is that modern excimer lasers are all safe, and give excellent results in the hands of a good careful eye surgeon. The differences between machines are like differences between tweeduldum and tweeduldee. Some machines handle odd treatments better, like high hyperopia (far-sightedness) or high astigmatism or high wavefront errors. However, for the vast majority of patients, it should not matter which machine you are treated on, provided that it is a machine model which is currently being manufactured.

There are six major excimer laser manufacturers. They are listed below, along with their current best models that are available (as on 1st July, 2009).

Company                                                                               Model                                                     Country

Carl Zeiss Meditec                                                             MEL 80                                                   Germany

Alcon/Wavelight                                                               Allegretto Eye-Q                                Germany

AMO                                                                                        Star S4                                                    USA

Technolas Perfect Vision                                               Zyoptix Z-100                                    Germany

Nidek                                                                                     Navex Quest                                         Japan

Schwind                                                                                Amaris                                                    Germany

All of the above are all excellent machines, and their manufacturers have a great deal of experience in designing and manufacturing excimer lasers.

In India, we also have several laser vision correction lasers installed, which are not excimer lasers, but solid state lasers from an Australian Company called CustomVis. We do not know much about the results of this laser, as there are few long term and credible studies about this.

Excimer lasers differ on the following parameters:

a) Speed of Treatment

b) Eye Tracker Characteristics and Speed

c) Ablation Profiles

d) Spot Size

e) Customization Features

In later posts, we will talk about implications of the different parameters, and how each laser scores on these aspects.