Do you wear glasses or contacts? Do you enjoy wearing glasses or contacts? If your answer to the first question was yes and the answer to the second question was no, then we’re on the right track.
LASIK is an acronym for laser assisted in situ keratomileusis, a form of refractive surgery. It aims to correct your refractive error – your eye’s prescription – through surgical means as an alternative to wearing spectacles that slip down your nose or contact lenses that cost hundreds of dollars every year.
The LASIK Procedure in a Nutshell
Refractive procedures such as PRK (photorefractive keratectomy), LASIK, and variations of LASIK such as epi-LASIK or LASEK, are based on reshaping the cornea, the clear dome of tissue at the front surface of the eye.
After having your eye numbed with anesthetic eye drops, your eye surgeon lifts the top layers of cells from the cornea, which makes way for a femtosecond laser to work on the deeper corneal tissues. In LASIK, this flap consists of the superficial epithelium and part of the corneal layers beneath. In epi-LASIK, the flap is designed to only include the epithelium.
Once the flap is out of the way, the femtosecond laser is put to work – guided by computer – to selectively vaporize sections of the cornea. Changing the shape of the cornea adjusts the way that light bends, or refracts, through this surface, with the aim to bring it to a sharp focus on the retina at the back of the eye.
After the femtosecond has done its job, the flap is replaced over your newly sculpted cornea. Your surgeon may insert a bandage lens to help the eye heal more quickly, and you’ll be given some prescription eye drops and a list of dos and don’ts while you’re in the recovery period.
Am I Suitable for LASIK?
This question can only be definitively answered by your surgeon after a comprehensive examination. However, in the meantime, you can appease your curiosity by casting your bespectacled eyes over this list of eligibility criteria.
1. Is your prescription stable?
There is no greater disappointment to pay thousands of dollars for laser eye surgery only to find your eyes haven’t stopped changing and you end up back in glasses or contacts. Most surgeons will want to see that your prescription has been unchanged for least one year. On a similar note, many surgeons will require LASIK candidates to be at least 18 years old, which is typically the age where prescriptions stabilize.
2. Are your eyes generally healthy?
Perhaps there is a greater disappointment than finding you still need glasses after laser eye surgery – and that would be finding out that the procedure was entirely pointless because your vision is limited by some other disease. Poor vision from conditions such as glaucoma, macular degeneration, cataracts, amblyopia, or scarring, will not be improved through laser eye surgery. In fact, some eye conditions can be worsened by laser surgery, such as dry eye or corneal degenerations.
3. Are you generally healthy overall?
Medical conditions that interfere with your body’s ability to heal may make LASIK unsuitable as there is an increased risk of an unsatisfactory outcome. Though there are no hard and fast rules about which diseases are okay and which automatically disqualify you from laser eye surgery, if you have any autoimmune conditions such as type 1 diabetes, AIDS, rheumatoid arthritis, or Sjogren’s syndrome, your eye surgeon will want to approach with caution. Pregnant or breastfeeding women are also advised to postpone laser eye surgery as hormonal changes can affect the prescription, alter the shape of your cornea, and lead to increased dry eye.
4. Is your prescription within the treatable range?
As a rule of thumb, LASIK is able to treat:
- Myopia (near-sightedness) up to around -10 diopters
- Hyperopia (far-sightedness) up to around +5 diopters
- Astigmatism up to around -6 diopters
However, additional factors can affect this treatment range, so falling within these parameters doesn’t mean an automatic tick. It is also worth remembering that the higher the prescription, the less predictable the results may be.
5. Do your corneas have sufficient thickness?
Because LASIK (and PRK, epi-LASIK, and LASEK) work by removing parts of the cornea during the reshaping process, it’s no good if there isn’t enough cornea to work with in the first place. One of the disadvantages of LASIK compared to PRK is that the formation of the corneal flap already reduces the amount of cornea available for reshaping. This automatically excludes everyone with corneas that don’t meet a minimum thickness. However, epi-LASIK sidesteps this problem by creating the corneal flap out of the epithelium only, leaving the rest of the corneal tissue intact and ready to be molded by that femtosecond laser.
During your initial consultation with a refractive surgeon, you’ll undergo a comprehensive vision and eye health check, as well as discuss your medical history. There will also be a discussion about the expectations of LASIK eye surgery, including potential risks and side effects. Once all the boxes are ticked, hello clear and uninterrupted vision!