What is LASIK surgery?
Laser-assisted in situ keratomileusis (LASIK) is considered one of the most common laser eye surgeries. LASIK surgery eliminates the need for eyeglasses or contact lenses as it reshapes the cornea in way that corrects the refractive error of the eye. It is used to treat nearsightedness (myopia), farsightedness (hyperopia) and distorted images defect (astigmatism).
What are the precautions to be taken before LASIK surgery?
Upon deciding to undergo LASIK surgery, an initial evaluation by the ophthalmologist is needed to assess if the person is a good candidate for LASIK surgery. If the patient is in fact fit for LASIK surgery, there are certain precautions he/she must follow before surgery.
Patients should stop wearing contact lenses weeks before surgery.
Wearing contact lenses alters the corneal shape which may affect the outcome of the surgery due to inaccurate measurements or poor surgical plan. So it is required from patients to abandon the use of contact lenses to allow the cornea to regain its natural shape before the surgery. The FDA recommends a specific lens-free period for each lens type:
- Soft contact lenses: Patients should abandon the use of this type of contact lenses 2 weeks before the pre-surgical evaluation.
- Toric soft lenses or rigid gas permeable (RGP) lenses: Patients should stop wearing this kind of lenses for at least 3 weeks before their pre-surgical evaluation.
- Hard lenses: Patients should not use hard lenses for at least 4 weeks before pre-surgical evaluation.
Patients should stop using cosmetic products like creams, lotions, makeup, and perfumes.
The presence of debris or cosmetics around the eye and the eyelashes increases the risk of infection. Patients are also advised to scrub their eyelashes for a period of time before surgery to wipe out any residues and debris.
Patients should arrange a ride home after surgery and also for their first follow-up visit.
During LASIK surgery, the doctor may give some relaxing medications that hinder the driving ability of the patient. In addition, vision may become blurry for some time after surgery. This applies even to people who do not usually drive; they too have to make sure they do not go home on their own.
How is the LASIK surgery performed?
LASIK surgery can be explained in 3 steps:
1- Flap Creation
A small device is used to keep the eyes open mechanically. After the ophthalmologist makes sure that the eyes are immobilized, he/she creates a lid-shaped opening in the outer part of the cornea that allows laser access to deeper parts of cornea. This lid-shaped opening is called the “flap”. There are two ways to create the flap:
Microkeratome is the mechanical way to create a flap. It involves the use of a blade.
On the other hand, there is femtosecond flap creation, also called the bladeless LASIK or All-Laser LASIK. IntraLASIK and Intralase LASIK are the two most common brand names for femtosecond LASIK. This technique involves the use of laser to create the flap. There are several advantages for femtosecond LASIK which include:
- Femstosecond LASIK is more accurate.
- The fact that a blade is not used relieves the patient’s stress before surgery.
- It helps in creating a thinner flap allowing the ophthalmologist to safely correct higher amounts of nearsightedness.
- It decreases the risk of induced astigmatism post-surgery.
- It allows for a more accurate prediction of corneal flap thickness.
- Femtosecond laser is able to create a flap that has edges. This promotes the healing process after surgery.
- It decreases the chance of corneal scrapping during LASIK.
- The surgeon can customize the size, shape and orientation of the flap according to the patient’s condition.
After the creation of a lid-shaped flap, one end of the flap is pulled back exposing the stroma while the other remains attached. During this part of the procedure, the patient might feel a little discomfort. As a result of the creation of a flap, vision becomes blurry and the patient sees only the surrounding colored lights.
For the patient, the surgery seems like a light show. This effect makes it harder for the patient to fix his/her eyes in one direction, that’s why an eye tracking device is used to compensate for any involuntary movement of the eye. This device monitors the positions of the eye and redirects laser pulses accordingly.
2- Laser remodeling:
The cornea is the transparent cover of the eye that captures the light reflected from objects, allowing the retina to focus the light and enabling us to see. In laser remodeling, an excimer laser is used to remodel and reshape the cornea in order to capture light properly. The laser vaporizes specific microscopic layers of the cornea
without affecting the surrounding stroma. The laser can flatten the cornea in nearsighted people, make it steeper for people with farsighted vision, or it can even any irregularity in the cornea for people with astigmatism. The patient does not feel any burning sensation as the excimer laser has low temperature.
3- Repositioning of the flap:
Once the reshaping is done, the ophthalmologist then turns the flap back to cover the remodeled cornea. He then checks for air bubbles and debris. The recovery is fast and easy because the flap is originally
created in the outer layer which is the highly regenerative part of the eye. Then the patient’s vision improves gradually after the surgery.
What are the measures to be taken after LASIK surgery?
There are measures that should be taken to ensure smooth recovery and optimum results after surgery. The patient will need to:
- Follow a course of antibiotic and anti-inflammatory eye drops as well as preservative-free moisturizing drops as prescribed by the doctor.
- Avoid wearing contact lenses.
- Avoid eye rubbing after surgery as this might displace the flap.
- Immediately visit the doctor in case of severe pain, worsening of vision or any other symptoms.
- Take a few days off from work.
- See the doctor after the first 24 to 48 hours after surgery then regularly for 6 month.
- Avoid the use of cosmetics for up to two weeks after surgery.
- Avoid strenuous sports such as boxing, football, karate, etc. for at least four weeks after surgery.
- Avoid swimming or using hot tubs for 1-2 months.
- Rest and wear dark eyeglasses to protect the eyes from bright lights and occasionally protective goggles to prevent rubbing of the eyes during sleep.