refractive surgery, myopia, hyperopia, myopic astigmatism, hyperopic astigmatism, presbyopia, laser surgery, visual defects, myopia surgery, laser surgery, eye laser,
excimer laser, PRK laser, LASIK, LASEK, radial keratotomy, surgical techniques myopia

REFRACTIVE SURGERY AND LASER SURGERY FOR VISUAL DEFECTS

(Myopia, Hyperopia, Myopic and hyperopic astigmatism)

The aim of refractive surgery is that of focusing light rays precisely on the retinal surface without the need of artificial aids such as eyeglasses or contact lens.

Modern refractive surgery is perfectly capable of correcting all types of visual defects, such as myopia, hyperopia or astigmatism.

In the case of myopia, since the light rays passing through the natural lens of the cornea become excessively convergent and they cannot focus on the retina, treatment will consist in the reduction of the power of the cornea that will reduce the convergence of light rays and result in precise focus of images.

In the opposite visual defect called hyperopia, the light rays passing through the cornea become insufficiently convergent and they cannot focus on the retina, treatment will consist in the increase of the power of the cornea resulting in precise focus of images.

In the case of astigmatism the corneal surface does not have a regularly spherical convex shape, in this case, far and near vision may be both affected, treatment will consist in giving a more regular shape to the cornea so that images will focus correctly.

The various Surgical Techniques

A proficient surgeon that is dedicated to his patient's well-being, must be well informed of various available surgical techniques, must continually update his knowledge, and chose the best technique of surgery for each patient considering the impairment he plans to correct.
Myopia, hyperopia and astigmatism can be treated on an outpatient basis using external eye surgery techniques providing that the visual impairment ranges from slight to medium/high (-1 diopter to -10/12 diopters). Both myopic and hyperopic astigmatisms can be corrected with the same techniques used for myopia and hyperopia

Higher refractive disorders may be corrected using internal ocular surgery, these techniques include implant of artificial IOL (Intraocular lens) and parallel IOL implantation (phakic lens).

The external surgical techniques include: radial keratotomy and excimer laser treatment in its many variants: PRK, LASIK, LASEK and EPILASIK.
The cornea, being the principal lens of the eye has a certain refractive power that is expressed in diopters, the aim of refractive surgery is to modify the power of the cornea that must be customized for each patient.