Surgical Techniques
Laser assisted in situ keratomileusis (LASIK) is a surgical procedure that can reduce the amount of nearsightedness (myopia), farsightedness (hyperopia) and astigmastism by reshaping the curvature of a patient's cornea. The cornea is the clear tissue located on the front surface of the eye. When performing LASIK, the eye surgeon first must create and peel back a thin flap of corneal tissue before using the excimer laser to reshape the central cornea. There are different surgical techniques that now can be utilized when creating the hinged flap of the outermost corneal layer. A microkeratome is a mechanical device that suctions to the front of the eye and contains a specialized blade that is used to create the corneal flap. Microkeratomes have been used since the advent of LASIK, but now ophthalmologists can perform bladeless LASIK by using a femtosecond laser. The benefits of bladeless LASIK include thinner flaps of more uniform thickness, and a possible decrease in flap complications. However, microkeratomes are extremely precise surgical instruments that yield excellent results under the care of a skilled ophthalmologist.
Wavefront LASIK
Wavefront LASIK, which is also referred to as custom LASIK, is a technology available with LASIK surgery that is designed to correct the visual distortion caused from higher order aberrations present in the eye. Nearsightedness, farsightedness and astigmatism are lower order aberrations that are due to the overall shape of the eye. Higher order aberrations are optical imperfections that can be present in the various optical structures of the eye. A wavefront aberrometer is a scanning device that can detect higher order aberrations. After performing aberrometry and testing a patient's vision, the eye doctor can determine if custom LASIK would be beneficial to the patient. Uncorrected wavefront aberrations could result in blur, halos or glare due to poor contrast sensitivity. A person affected by poor contrast sensitivity may be able to read the 20/20 row on the chart but still complain that the letters are not sharp or crisp. These symptoms can vary depending upon lighting conditions. It is important for patients to trust their eye doctor with the proper recommendation because many individuals may not be significantly affected by wavefront aberrations and cost can be a major consideration.
Considerations
There are inherent risks present with any type of surgery, which is why it is important for patients to be well educated about LASIK surgery and to have the procedure performed by a highly qualified eye surgeon. A complete medical history must be taken to rule out any risk factors that could lead to complications. One consideration is that people with dry eye syndrome may have more ocular discomfort after LASIK. Medicated eye drops are often prescribed during the postoperative period to decrease the incidence of these symptoms. Patients older than 40 years must also understand that reading glasses will likely be needed after LASIK if both eyes are corrected surgically for clear distance vision. The most important considerations are to be knowledgeable about realistic LASIK outcomes and to adhere to the professional care of a trusted eye doctor.
