The Different Types of Laser Eye Surgery

Laser eye surgery—for correcting nearsightedness, farsightedness, and astigmatism—falls into two main categories.

The first is called PRK (Photorefractive Keratectomy), where a surface ablation technique is used to take away the cornea's outermost layer (epithelium), as opposed to cutting to create a flap, as in the second kind of eye surgery, LASIK (Laser-Assisted In Situ Keratomileusis).

Laser eye surgery generally lasts from less than a minute to a minute per eye, and is performed while the patient is awake (drops are used to numb the eye).

PRK
PRK usually entails a lengthier recovery period and more uneasiness than LASIK. However, unlike LASIK, PRK does not use a blade to cut and create a corneal flap, which is the riskiest eye surgery procedure.

Furthermore, PRK does not deeply invade the cornea. This reduces the risk that inner eye pressure will push out against the thinned corneal wall, making it bulge and causing deteriorating vision over time (ecstasia).

There are two laser eye surgery variations under PRK:

1. LASEK (Laser Assisted Sub-Epithelial Keratomileusis) is a more sophisticated form of PRK that utilizes alcohol to soften and remove the epithelium. LASEK’s advantage over standard PRK is that the eye will heal faster even if the procedure still avoids using a blade to create a corneal flap.
   


2. Epi-LASEK modifies the LASEK procedure by using a ‘separator’ to maintain a living layer of epithelium, which is then substituted after the laser modifies the eye. This type of eye surgery reduces discomfort and speeds up healing even better than LASEK.

LASIK
This popular procedure entails using a metal blade to make an incision on the corneal flap and a laser to reshape the eye, after which the flap is put back to its original position.

LASIK is generally painless and, unlike PRK, the patient’s vision is corrected immediately (although blur vision has been observed during the first 24 hours).

Variations on LASIK eye surgery exist that use different hardware to increase the accuracy of the procedure.

VERBUM SAPIENTI
The 20/20 vision that results from laser eye surgery may not be the same as the 20/20 vision achieved with corrective lenses. Also, hazy vision and other side effects have been known to result from laser eye surgery—although technological advances are constantly being developed to eliminate these.

It is generally true that the latest techniques, which carry the least risk of side effects, are often the more expensive.

Not everyone is a candidate for laser eye surgery. But there are other types of eye surgery (some non-surgical) that individuals excluded from laser eye surgery may consider.

On the other hand, individuals that have undergone RK (Radial Keratotomy), a form of corrective eye surgery that predates today’s laser procedure, may still be candidates for PRK and LASIK.