LASIK for Hyperopia
WHAT IS FARSIGHTEDNESS?
In the normal eye, light bends through the cornea and lens to focus on the retina. With hyperopia (farsightedness – place cursor over image) the eye is shorter (or cornea is flatter) causing the focal point of light to be behind the retina. The image is therefore out of focus on the retina and vision is blurred.
1. A thin flap of cornea is created and folded back.
2. Excimer laser is applied to reshape (ablate) the cornea.
3. The corneal flap is replaced over the treated cornea.
4. The “steeper” cornea now bends light to become focused on the retina.
Before LASIK treatment, light traveling in the horizontal meridian (in this case blue) is out of focus on the retina. After LASIK treatment (place cursor over image), the “steeper” cornea (arrow) causes light to bend in such a way as to become focused on the retina. Vision is clear.
Laser in-Situ Keratomileusis (LASIK) can be used to treat low to high levels of farsightedness (hyperopia) with the goal of reducing or eliminating dependence on corrective lenses. Farsightedness occurs when the cornea is too flat or the eye is too short. This causes the focal point of light to fall behind the retina, rather than on the retina, resulting in blurry near vision. LASIK uses the computer-controlled precision of the Excimer laser to treat the inner tissue of the cornea.
The procedure is done using eye drop anesthesia, and while you may feel pressure, the technique is not painful. First, an instrument known as a microkeratome makes a protective flap in the outer layer of the cornea. Next, the Excimer laser sculpts the internal corneal tissue to the correct refractive power by steepening the curvature of the exposed corneal tissue. The “steeper” cornea allows light rays to focus more directly on the retina, thereby reducing farsightedness. After a few minutes of drying, the corneal flap is laid back in its original position. Due to the cornea’s extraordinary natural bonding qualities, stitches are usually not required.
Although the vast majority of patients see 20/40 or better postoperatively, individual results cannot be guaranteed. The surgery is performed on an out-patient basis and most people return to work within one to three days. As with any surgical procedure, side effects and complications may occur.
Before your consultation to evaluate you for LASIK, we ask you to discontinue soft contact lens wear for two weeks prior to your visit. Hard or rigid gas permeable (RGP) lens wearers should discontinue contact lens wear for three weeks prior to their visit. This is to prevent errors in measurement (due to potential warpage of the cornea) which could lead to under or over-corrections after surgery.
Selected images copyrighted and licensed by Stephen F. Gordon