LASIK (laser-assisted in situ keratomileusis) uses a laser beam to treat hyperopia (farsightedness), myopia (nearsightedness) and astigmatism. In all the three conditions, light is incorrectly bent so that it focuses elsewhere resulting in a blurred vision. Usually, the blurred vision is corrected using glasses and lenses. Those who wish to do away with glasses and lenses can opt for LASIK.
LASIK is an outpatient procedure that surgeons use to reshape the cornea. A reshaped cornea improves how the eye focuses light on the retina. LASIK is the most popular refractive surgery.
Doctors do not recommend LASIK for people with certain conditions like autoimmune disorders, a weakened immune system, pregnancy, persistent dry eyes, glaucoma and so on. LASIK is also not for people with keratoconus, reasonably good overall vision, severe nearsightedness among others.
Types of Surgery
- Spot scanning lasers which use small diameter beams to show the zone to be treated
- Slit-scanning lasers (small excimer beams) which enlarge and increase the ablation zone
- Wavefront-guided lasers which enable the surgeon to create a unique treatment plan customized to the patient’s needs
The goal of LASIK is to improve vision. For myopia patients, LASIK flattens a cornea that is too steep. On the converse, LASIK will create a steeper cornea in hyperopic patients. LASIK will also reshape an irregular cornea for those with astigmatism.
Preparation and Expectation Before Surgery
The eye care professional will take a detailed medical history and conduct a thorough eye examination. The doctor is looking for things like intraocular pressure, visual acuity, infections, inflammations and so on. These can have a negative impact on the surgery.
The doctor measures the cornea and assesses which parts need reshaping. This examination helps to determine the precise amount of tissue to remove from the cornea. The examination is done using wavefront-guided technology.
Those who wear contact lenses must stop wearing them a few weeks before the procedure. Individuals must also do away with makeup and other cosmetics a day before the operation.
To avoid disappointment and unrealistic expectations, individuals need to know that LASIK does not necessarily promise perfect vision. Some people may require glasses or contact lenses after surgery. About 90% of those who undergo LASIK attain a vision between 20/20 and 20/40 without having to use lenses or glasses.
It’s essential for those preparing for LASIK to understand that they might need to undergo a second surgery called retreatment or enhancement. This mostly affects individuals with higher astigmatism, hyperopia and myopia. They may require glasses for activities like reading or driving at night. Besides, LASIK is not a cure for presbyopia, a condition that affects older people so that they lose close-up focusing power.
The patient will recline under an excimer laser (a surgical device) in an outpatient surgical suite. The ophthalmic assistant numbs the eye with a few drops of topical anesthetic.
The surgeon will then do the following:
- Use an eyelid holder to prevent the patient from blinking. The surgeon will place a suction ring on the eye to lift and flatten the cornea. This action keeps the eye from moving. The ring and eyelid holder can cause the patient to feel pressure on the eyelid. The effect of the suction ring causes a dark vision.
- With the laser correctly positioned, the surgeon directs the patient to look at a target light (fixation). A hinged flap of corneal tissue is created by use of an automated microsurgical device. This device is either a laser or blade which the surgeon uses to lift a thin flap in the cornea. He/she then folds the flap back and using an excimer laser, proceeds to sculpt away a certain amount of corneal tissue under the flap. The surgeon returns the flap to its original position for healing to take place. It takes about five minutes for the corneal flap to stick to the underlying corneal tissue. There is no need for stitches.
- Preprogram the excimer laser with the patient's unique eye measurements.
- The surgeon may put a shield over the eye. The guard protects against accidents and rubbing of eyes. The patient may be required to wear the shield while sleeping.
After Care, Recovery, Results
After the surgical procedure, the patient will be advised to go home and take a nap. There must be someone to drive the patient home. To help in recovery and to protect against dryness, the surgeon may prescribe eye drops.
It takes about three to six months for the patient to achieve stability in vision after LASIK. Visual outcomes depend on the severity of the problem before LASIK. The result is usually good with most patients since 8 out of 10 no longer need their glasses or lenses for most activities. Side effects also take the same length of time to go away.
A follow-up appointment is usually set up a day or two after the procedure.
The patient can resume using makeup and doing contact sports several weeks after LASIK.
Risks & Complications
Just like in any other surgical procedure, the following risks or complications may arise after a LASIK procedure:
- Astigmatism may result from LASIK. The uneven removal of tissue causes it
- Infection and inflammation. The surgeon may prescribe certain medications which to clear them
- Overcorrection may happen when the surgeon removes excess tissue. This error is more difficult to fix
- The likelihood that vision may not be as good as before LASIK surgery even while using eyeglasses or contact lenses
- Undercorrection could result if the surgeon removed less tissue. It's usually more common with patients with nearsightedness
- Corneal flaps may present a problem requiring further treatment. The epithelium may grow abnormally under the flap as the eye heals
The following side effects may result from LASIK but they disappear with time:
- Sensitivity to light
- Pain or discomfort
- Hazy or blurry vision
- Glare or halo around lights
- Redness on the white part of the eye
- Difficulty seeing at night or driving at night
- Dry eyes which are corrected by the use of eye drops or another surgical procedure where the doctor puts plugs inside the tear ducts
- Some of the side effects may be permanent in some people