More than one hundred fifty clinical excimer laser units designed for corneal surgery have been
developed and sold commercially. Manufacturers include Meditec Lasers in Germany, Summit
Engineering, Taunton Technologies, and Visx in the United States, and Synthelabo in France.
Furthermore a number of prototypes have been built in the USSR and other countries which are being
investigated for their clinical use.
While in the United States and Canada, substantial regulation of these devices has limited their
distribution and use, sales in other parts of the world have been restricted only by market forces. Early
clinical successes have created an enthusiasm for this new technology. In spite of this, substantial
technical issues remain uncertain and have not been carefully studied. Indeed we have accepted certain
parameters for on an almost serendipitous, empirical basis. It is a proper time to pause and consider
the bases for these laser techniques.