Laser refractive eye surgery is used to correct the following vision conditions:
There are two types of Laser refractive surgery:
Laser-Assisted-In-Situ Keratomileusis (LASIK)
LASIK is the most frequently performed elective surgery in North America. This highly effective outpatient procedure is often referred to as refractive surgery or laser vision correction.
How LASIK Works
The LASIK procedure is performed by ophthalmologists, medical doctors who specialize in surgical treatments of the eye. Here is a general outline of the procedure:
Anesthetic eye drops are applied to the eye.
The LASIK surgeon creates a protective flap to access the inner corneal tissue. During this part of the procedure, your vision dims and becomes blurry for about a minute. After the flap is created you are able to see the flashing fixation light of the laser and the bright lights used for the procedure.
Next the inner layers of your cornea receive computer-controlled pulses of cool laser light. Although the laser light is invisible, the laser makes a clicking sound as it gently reshapes the inner corneal layer to improve and in many cases, eliminate your prescription. During this part of the procedure, an eye-tracking device tracks your eye movements to ensure precise correction.
Following the re-shaping of the tissue, the LASIK surgeon carefully repositions and aligns the flap to its original position. Protective shields are placed over your eye to prevent accidental rubbing as the flap heals naturally and securely over the next several hours.
After the LASIK eye surgery procedure, patients feel moderate discomfort and irritation for a few hours, but most are comfortable after a nap and rest.
Occasionally LASIK cannot be done as the cornea is too thin to create a flap or there may be slight imperfections in the corneal surface, or if you have had LASIK before and require an enhancement a year or more later.
PRK was the first type of laser eye surgery for vision correction and is the predecessor to LASIK. The main difference between PRK and LASIK is that in LASIK surgery a thin flap is created, whereas in PRK the surface of the cornea (epithelium) is removed and no flap is created.
The laser then reshapes the tissue just below the surface. A bandage contact lens is inserted and although the final outcome is similar to LASIK, initial PRK recovery is slower because it takes a few days for new epithelial cells to regenerate and cover the surface of the eye. In this case, we see PRK patients each day until the surface is healed and then we remove the bandage contact lens.
There often is haziness of vision in the first few days after surgery so it is adviseable to take one week off of work if you are having PRK. Vision gradually improves over days but can take weeks to become optimal.
Am I good candidate for LASIK ?
To be eligible for LASIK surgery, potential candidates must meet the following criteria:
- Age: Candidates must be at least 18 years old.
- General health: LASIK candidates must be in good general health, and should not have certain health problems, including uncontrolled diabetes, autoimmune or collagen vascular disease, or take any medication or have any condition that compromises the immune response.
- Eye health: Candidates should be free of eye diseases including keratoconus, glaucoma, cataracts, corneal disease and certain retinal and optic nerve diseases. LASIK surgery candidates should not have certain eye conditions including herpes simplex and herpes zoster.
- Eye problems: LASIK patients should make their eye doctor aware of certain eye problems including amblyopia (lazy eye), strabismus (muscle imbalance), or any recurrent, residual or active eye conditions that may influence healing. Other conditions that should be discussed with the doctor include keloid scarring with previous surgical healing, back problems and claustrophobia. Please make your eye doctor aware of any mental health conditions, as these may also affect your LASIK surgery or recovery.
- Eye injury: Patients should not have any eye infections or injury.
- Nursing/pregnancy: Candidates should not be nursing or pregnant when undergoing the LASIK procedure. Hormones may affect the stability of your prescription, so pregnant or nursing women are not eligible to pursue LASIK surgery until three menstrual cycles after nursing has been discontinued.
- Dry eye condition: Patients should not continuously suffer from dry eyes.
- Stable vision: Candidates’ vision must be stable for at least one year prior to the procedure date.
- Contacts: Prior to your LASIK surgery consultation and LASIK procedure, you must not wear contact lenses for a certain length of time. The precise length will be determined by your doctor on an individual basis. This ensures corneal stability and accurate assessment of your prescription prior to the LASIK surgery procedure.
- Corneal thickness plays an important role in determining proper candidacy for LASIK. Due to the nature of the procedure, candidates must have a minimum corneal thickness of approximately 0.5 mm.
- Vision as you get older- if you have successful Laser Refractive surgery and you are ages 19-35 it is important to realize, unless medicine has a major breakthrough, you will still require glasses for closework as you reach age 35-45 and beyond.
LASIK can treat severe degrees of nearsightedness, moderate amounts of farsightedness and astigmatism, but LASIK is not right for everyone. While the goal of LASIK surgery is to reduce dependency on glasses or contact lenses, having LASIK cannot guarantee 20/20 vision. Fortunately, most individuals, who are screened appropriately attain excellent vision.
Some risks exist with Laser Refractive Surgery:
- Over or Under-Correction -if this occurs a second surgery may be required (enhancement)
- Glare, Halos at night – this could occur if you are not screened properly and you have large pupils. A reputable laser centre should be evaluating this at a pre-op appointment
- Infection – this is possible if drops are not used as instructed after the surgery or if the individual returns to work in a dusty or dirty environment too quickly.
- Dry Eyes – LASIK causes a temporary decrease in tear production. This is why individuals who have dry eye before surgery may not be a good candidate and why lots of lubrication is recommended after laser surgery.
Laser refractive surgery can be a life altering experience if you are determined to be a good candidate by your optometrist, you have the surgery at a reputable laser centre (it’s not a haircut), and you follow the pre and post operative care instructions carefully.