The individuals suffering from astigmatism must be extra cautious while considering LASIK surgery.
The individuals suffering from astigmatism must be extra cautious while considering LASIK surgery. Since the surgery involves manipulation and restructuring of the cornea, LASIK and similar procedures can sometimes worsen astigmatism.
However, with advances in technology and precision instruments in ophthalmology, most disadvantages can be minimized. You may consider LASIK after a detailed discussion with your eye doctor.
The following three procedures can be considered in the individuals suffering from astigmatism:
LASIK (laser in situ keratomileusis):
- This is an FDA approved procedure that does not need hospitalization. It takes about an hour to complete.
- The doctor will make a flap on the cornea surface using a laser beam. The cornea is then restructured under the flap and the flap is replaced. An excimer laser is used to reshape the cornea.
- The reshaping of the cornea can alter the way the light falls on its surface and correct the refractive error.
LASEK (laser-assisted subepithelial keratomileusis):
- This procedure is a modification of LASIK.
- The first step of raising a flap is not followed here.
- Instead, the outer corneal layer is loosened using an alcohol solution.
- Then the laser is used to reshape the cornea.
- This procedure is well suited for individuals who have thin corneas (often seen in contact lens users) and dry eyes.
PRK (Photo Refracto Keratotomy):
- This is also preferred in individuals with thin corneas and dry eyes.
- No flap is raised, or alcohol is used here.
- A laser beam is directed to restructure the cornea and improve the vision.
LASIK surgery can correct from -1.5 D to -5 D astigmatic defect in the cornea.
What is LASIK surgery?
LASIK and the related surgeries aim to correct refractive errors of the eye. The usual refractive errors corrected using LASIK surgery include:
- Myopia (near-sightedness): With this condition, you cannot clearly see far away things.
- Hypermetropia (far-sightedness): With this condition, you cannot read or operate laptops but things far away are clearly visible.
- Astigmatism: The cornea of the eye is irregularly shaped. Because of this, the image formed in the eye is blurry.
The cornea is the clear outer eye layer that lies above the iris (colored part of the eye). The cornea focuses the light falling on the eye to the lens that lies inside the eye. LASIK procedures involve manipulating and reshaping the cornea so that the image formed by the lens falls exactly on the retina (part of the eye that generates vision signals and sends them to the brain). This eliminates the need for specs or contact lenses.
Does LASIK surgery have any disadvantages?
LASIK surgery is a minor procedure done on an outpatient basis. The following are the potential disadvantages of LASIK:
- Dry eyes: This is one of the common problems after the procedure. It may persist for about 6 months after the surgery.
- Corneal ectasia: This is more common in individuals having a thin cornea. A part of the cornea thinned during the procedure may bulge out. This thinned-out part may burst and cause a serious infection of the eye.
- Glares, halos around the eye: Many people may experience the inability to tolerate lights, see rainbow-like rings (halos) around the light sources, and have excessive watering of the eyes.
- Under correction: Removal of flaps less than what is required may not correct myopia completely. The person may still need to wear spectacles with lesser power lenses.
- Overcorrection: Excess restructuring of the cornea may push a nearsighted person into being a farsighted person.
- Flap issues: The infection of a flap or a tear of the corneal flap may result in permanent vision loss.
The LASIK may not have a favorable outcome in these patients:
- Individuals with diabetes
- High myopia (more than -8 D, though up to -12 D is approved in the US)
- Thin cornea
- High eye pressure
- Younger than 21 years
- Constantly changing eye power
- Individuals with rheumatoid arthritis
- High astigmatism