HISTORY OF REFRACTIVE SURGERY
A SHORT HISTORY OF LASER REFRACTIVE SURGERY
From the middle ages, glasses have been the principal way to correct inadequate vision. In the first half of this century, contact lenses were developed as an alternative to spectacles for practical and social reasons. With the astonishing speed of 20th century technological development, the Excimer Laser has developed over just ten years into an acceptable, safe and reliable means of changing the focus of the eye itself.
In the 1970s, excited dimer (Excimer) laser was developed at IBM to etch microcircuit boards. From 1983, ophthalmologists recognized its micro precision and the lack of thermal damage caused to tissue immediately beside the treated area. Following animal and human studies, the first large scale patient treatments began in 1990. An explosion of knowledge, experience and technology followed, resulting in today's science of refractive surgery.
Just as the laser has developed, so too has its method of delivery. Computer driven aiming of the laser beam allows variable patterns of treatment to correct different types and amounts of refractive error. At the cornea, the laser may be applied to the surface, "PRK", or to an inner layer temporarily exposed by raising a hinged flap, the "Lasik" technique. The microkeratome, the instrument used to precisely cut this flap, has been refined since 1949. Lasik has many advantages over surface PRK but also some significant risks which must be understood.
The programmable "flying spot" laser is the latest development in delivery of the laser beam to the cornea. The shape of the treatment can be customized for any individual and new possibilities for correcting a wider range of errors, corneal scars and decentrations are now available.
