LASIK and Refractive Surgery Options in Houston
So What is “Refractive Surgery”?
The American Academy of Ophthalmology defines laser refractive surgery as a method for correcting vision for people with near-sightedness (myopia), far-sightedness (hyperopia), astigmatism, or presbyopia (the age-related loss of near focus). In short, refractive surgery is simply a surgical means to reduce one’s dependence on glasses or contacts. For many, it can provide a freedom to pursue a more active lifestyle without the encumbrances and expense of external visual aids. Having been available in the United States for over twenty-five years, these procedures have been extensively fine-tuned. One series of over ten thousand LASIK patients in the Navy demonstrated a 99% rate of vision correction of 20/20 or better.
The most commonly performed refractive surgery in the united states (not including cataract surgery) is LASIK (laser-assisted in situ keratomileusis). Most modern LASIK surgery is usually ‘blade-free’ or ‘all-laser LASIK’. In this procedure a thin flap is created by a gentle and precise laser in the superficial cornea. The flap is then folded back and a separate excimer ‘cool temperature’ laser is used to precisely reshape the cornea. Total laser time with modern lasers typically ranges between 10-60 seconds. Over 30 million LASIK surgeries have been performed since it’s introduction in the United States. Advantages of LASIK include rapid visual recovery (many patients can drive by the next day after surgery), short procedure time – usually less than ten minutes for both eyes, and minimal discomfort after the procedure – patients may feel some minor foreign body sensation the first few hours after the procedure which generally resolves by the next day.
The SMILE (small incision lenticule extraction) procedure is a relatively new refractive procedure in the United States, however, it has been in wide-spread use in Europe and Asia for almost ten years. Over one million procedures have been performed in over sixty countries world-wide. In this procedure a femtosecond laser (the same class of laser commonly used to create LASIK flaps) is used to gently and precisely reshape the cornea by removing a small lenticule of tissue through a tiny window in the periphery of the cornea. It takes an average of twenty-three seconds of laser time and only requires one laser to perform the entire procedure (as opposed to two lasers with LASIK). Advantages of the SMILE procedure over LASIK include no risk of flap dislocation, greater comfort during and after the procedure, less risk of dry eye, and potentially greater biomechanical stability of the cornea. The SMILE procedure and LASIK achieve similar visual acuity results *at one month, six month, and one year intervals.
PRK (photorefractive keratecomy) can most easily be defined as ‘LASIK without the flap’. In this procedure, the very thin surface layer of the cornea, the epithelium, is gently swept away, and the excimer (LASIK) laser is used to precisely reshape the cornea. The defining feature of PRK is the avoidance of making a flap. Historically this procedure has been recommended for patients at risk for high impact trauma such as public safety officers, military personnel, or boxers. However, as more experience with LASIK has accumulated, the risk of LASIK flap dislocation, even in these high-impact activities has been determined to be very low. Other applications of PRK include laser refractive surgery in patients with thin corneas or patients at increased risk for keratoconus, a corneal steepening condition related to thin corneas.