

Click here to review Myopia & Astigmatism

In myopia either the cornea
(front of eye) has too much curvature or the eye is too long. It is possible and
most likely that in the higher powers that the cause is a combination of the two
factors. In astigmatism the cornea basically has two different curvatures and
thus the vision is distorted. The surgical techniques all work on the cornea to
effectively flatten the curvatures. In the case of myopia the curves are
flattened equally and in astimatism only the steeper curves is flattened to
equal the flatter curvature. In the case of myopia and astigmatism a combination
of the two is done. Even if the cause of the myopia is a long eye, flattening
the curvature of the cornea will reduce the myopia. The following is a general
overview only and each case should be discussed throughly by the patients
eyecare practitioners.
In hyperopia either the cornea (front of eye) has too little curvature or the eye is too short. It is possible and most likely that in the higher powers that the cause is a combination of the two factors. The laser techniques effectively steepen the curvatures to correct the hyperopia. Techniques are available to correct hyperopia along with astigmatism. As always the skill of the surgeons and proper care is paramount for a successful outcome.
In PRK and LASEK the Laser is used to reshape the
cornea. This treatment uses a computer driven laser (directed by surgeon) that
removes the outermost layer of the cornea in a predetermined amount. It removes
more from the periphery and less from the center thus flattening the cornea to
correct or reduce the myopia. In both these procedures no flap is created prior
to the laser being used. The main difference between the two is how the
epithelial layer is removed prior to the application of laser. 

last update 2/15/05