Is PRK / ASLA the best laser vision correction procedure for you?

When considering laser vision correction there are many things to understand and decide.  After your evaluation and examination, you may be deemed a candidate for both LASIK and PRK/ASLA.  Making the decision between LASIK and PRK/ASLA can be difficult, but there are some important differences to consider.  To help understand the procedures and to assist with your decision, I will highlight some of theses considerations. 

The two most common reasons why people select PRK/ASLA over LASIK are:

1. Concern about LASIK flap trauma or flap complications.  A heavy blow to the eye with a finger or other object may dislodge a LASIK flap and cause vision loss.  Only you know how likely you are to suffer an injury to the eye.  If you think you are at high risk of an injury to the surface of the eye, PRK/ASLA may be your preferred treatment. 
2. Concern about post-LASIK ectasia.  During your complete eye examination and screening tests for refractive surgery, Dr MacIntyre will advise you of your risk of ectasia.  Factors that may affect your risk include your age, the thickness of your cornea, your refraction or strength of your current glasses prescription, and your corneal mapping or topography.

The most common reasons why your ophthalmologist may suggest PRK/ASLA over LASIK are:

1. If your cornea is too thin or borderline for LASIK.  If LASIK is performed in this situation it may put you at risk for developing an ectasia, or a progressive increase in the curvature of your cornea.  This can lead to deteriorating vision that changes as the cornea changes shape.
2. If you are at high risk for facial trauma.  If you play contact sports such as martial arts or boxing, or have hobbies that increase your risk for facial or eye trauma, LASIK may not be recommended.   
3. Pre-existing eye disease.  If you have epithelial basement membrane dystrophy (EBMD) or have superficial scarring on the cornea, PRK/ASLA may be better options.  EBMD can cause the epithelium to be loose which may lead to epithelium sloughing during the laser procedure.  If sloughing occurs during LASIK surgery, there is a higher risk of an under-correction, epithelium growing under the flap, and inflammation under the flap.  Each of these could lead to reduced vision after LASIK surgery.  Superficial scarring on the cornea, whether it be from prior trauma or a mild infection, can cause difficulty creating the flap for LASIK.