LASIK & Laser Vision Correction
Understanding Laser Eye Surgery
When considering vision correction, it is essential to understand that there are several different options available. Not all forms of vision correction are right for everyone. LASIK is a very popular option, but depending on your specific eye condition and health, other options may prove to be more suitable for you. Having a comprehensive eye consultation at Lexington Eye Associates will allow Dr. Kieval to determine the best form of vision correction for you. Below are the different types of laser vision correction provided at Lexington Eye Associates.
LASIK
LASIK (Laser In-Situ Keratomileusis) is necessarily a two-step procedure. The first step is the creation of a thin protective flap on the cornea, and the second step involves the actual correction of one’s vision. Though many LASIK surgeons still use surgical blades for the first step, Dr. Kieval exclusively uses a bladeless technique with the IntraLase® laser, in which microscopic pulses of light create the corneal flap. With its precision accuracy, IntraLase® technology has led to better visual outcomes with higher percentages of patients achieving perfect vision. More importantly, IntraLase® has greatly reduced and nearly eliminated complications during the procedure. The process takes approximately 20 seconds from start to finish.
Once the protective flap is folded back, the next step of LASIK—the reshaping of your cornea—can be performed. A second ultra-precision laser, the VISX STAR S4™ with ActiveTrak™, is then used to gently reshape the cornea. This process takes anywhere between 10 to 60 seconds, depending on your prescription.
When your LASIK treatment is over, the flap is securely repositioned into place, where it bonds with your eye without the need for stitches. The focus of light will now have been shifted to allow for perfect vision without the use of glasses or contact lenses.
Lexington Eye Associates performs LASIK eye surgery in Concord MA., Lexington, MA, and Arlington MA. We also help patients of the greater Boston area with LASIK eye surgery and vision correction procedures.
PRK
PRK (photorefractive keratectomy) was performed in the mid-1980s and was the precursor to LASIK for laser vision surgery. Although LASIK has now surpassed PRK as the most common refractive surgery, PRK is still an excellent alternative for patients who cannot undergo LASIK surgery.
Simply put, PRK is LASIK without the creation of a corneal flap.
Like LASIK, PRK utilizes the same ultra-precision laser, the VISX STAR S4™ with ActiveTrak™, to reshape the cornea. In PRK, however, the first step of the procedure simply involves removing the outer “skin” layer of the cornea, called the epithelium. With LASIK, the laser is applied to the inner tissue of the cornea, whereas with PRK, the laser is used on the surface of the cornea.
Results take longer to achieve with PRK than LASIK because it takes longer for the epithelium to regenerate and be fully restored. LASIK can often produce a clear vision within hours; PRK, on the other hand, may take several days or even weeks to recover clear vision.
Despite this difference, numerous studies have been performed to demonstrate that there is absolutely no difference in the final visual results when comparing PRK to LASIK. It is therefore a fantastic alternative for patients who may not be candidates for LASIK, those with specific technical requirements, or others with specific corneal conditions.
LASEK
Laser-Assisted Sub-Epithelial Keratectomy (LASEK) is a variant of PRK that combines elements of PRK and LASIK. During the procedure, the epithelium is loosened from the underlying tissue with the use of diluted alcohol. This “flap” of surface epithelial cells is then reflected back, and the laser is applied to the surface of the cornea. The “flap” is then repositioned back into place after the laser application. The advantages of LASEK over PRK are a topic of significant controversy. Although some refractive surgeons believe it provides improved comfort and more rapid healing compared to PRK, most studies have not found this to be the case.
Epi-LASIK
Epi-LASIK is also a variant of PRK that, instead, combines elements of LASEK and LASIK. Epi-LASIK is essentially the same procedure as LASEK, but the epithelial “flap” is created using a special modification of the microkeratome blades generally used to make the (deeper) LASIK flap.
The advantage of the Epi-LASIK over LASEK is that no alcohol is used to create the epithelial sheet. This procedure has been shown to result in more rapid recovery and improved comfort when compared to PRK or LASEK.
However, for the same reasons that Dr. Kieval has abandoned the use of microkeratome blades for LASIK, Epi-LASIK possesses increased risk that is obviated by simply performing PRK.
Monovision
“Monovision” is a technique used to deal with the correction of presbyopia, the gradual loss of the ability of the eye to change focus for close-up tasks, which progresses after the age of 40. This practice was first applied successfully for contact lens wearers, in which one eye is fit with a contact lens to correct distance vision, and the other eye is fit with a contact lens to correct near vision. Similarly, with LASIK, a patient has one eye operated on to correct the distance vision, and the other operated on to correct the near vision.
Patients over the age of 40 who have symptoms of presbyopia have a choice. If both eyes are corrected to see well in the distance, then glasses will be needed for close-up work. The alternative is monovision. Monovision represents a compromise that allows for the preservation of both distance and near vision without the use of glasses. The majority of patients have no difficulties with this procedure, and it is the most common technique requested by eye specialists undergoing laser vision correction. A contact lens trial will always be performed prior to surgery to mimic the monovision effect and determine a patient’s level of comfort.
