Laser Vision Correction – Treating Refractive Errors

What eye conditions does LASIK eye surgery correct?

LASIK is an outpatient surgical procedure that uses laser technology to reshape the cornea and correct eye conditions like myopia, hyperopia, and astigmatism. The eye’s ability to focus objects is affected by the length of the eye, the curvature of the cornea and curvature of the lens. The cornea and lens focus light to form an image on the retina. In people with perfect vision, light is focused directly on the retina. When the cornea is irregularly shaped, an image is not refracted properly, preventing light from being focused properly on the retina. The reshaping of the cornea by laser surgery can correct nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.

What is Myopia?

Myopia, or nearsightedness, occurs when the eyeball is too long and so the curvature of the cornea is too steep for the eye. The cornea therefore refracts light too much and images are focused in front of the retina, causing distant vision to be blurred. This refractive error occurs in about 30% of the U.S. population. Heredity and visual stress can cause nearsightedness.

What is Hyperopia?

Hyperopia, farsightedness, is a condition in which the eyeball is too short and so the cornea is too flat for the shape of the eye. Light is not refracted enough and reaches beyond the retina. Symptoms of hyperopia entail headaches after work at close range, eye strain, and difficultly with focus on close objects.

What is Astigmatism?

This refractive error occurs when the shape of the eyeball is more oval (like a football), rather than perfectly round. The cornea or lens is therefore irregularly shaped for the eyeball. The eye cannot focus light on the retina at any single point, causing objects to be blurred, whether far or near. This condition is very common and is usually associated with eye discomfort and frequent headaches. Astigmatism usually occurs along with nearsightedness or farsightedness. Astigmatism can be hereditary, or can develop as result of an eye injury.

How can these refractive errors be treated?

Often eyeglasses or contact lenses are prescribed to treat these errors. The alternative to wearing glasses or contacts is laser eye surgery. The most common laser eye procedures include LASIK or Photorefractive Keratectomy (PRK).

The most commonly performed LASIK vision correction is iLASIK. Good candidates for iLASIK include patients with myopia up to -12.00, hyperopia up to +4, and astigmatism as high as 6.00 diopters. 94% of people who are over 21 years old and in good general health, including no existing eye disease are good candidates for this procedure.

At the Eye Center of Texas, iLASIK is the only LASIK procedure offered. It is the most advanced and safest LASIK vision correction. The IntraLase method, a blade-free method that creates a corneal flap, is used in conjunction with the Advanced CustomVue Wavefront-guided VISX excimer laser technology that reshapes the cornea. This custom LASIK procedure uses iris registration to obtain a custom fingerprint of your vision in order to properly correct your vision. IntraLase combined with CustomVue is 25 times more precise that conventional LASIK. The procedure is done within a few minutes.

For patients with severely abnormally shaped corneas or very thin corneas, PRK is another laser eye surgery available. This procedure is laser treatment without the flap. PRK removes the epithelium of the eye, which is a layer of cells that cover the cornea’s surface, and uses laser technology to reshape the cornea, whereas Lasik removes the inner tissue of the cornea. PRK still uses iris registration.

Another option for non LASIK candidates is Visian ICL, which involves a lens implant to correct these refractive errors. This is an alternative to corneal refractive procedures (Lasik or PRK). This is an excellent option for patients that have been told they are not candidates for LASIK or PRK.