Custom LASIK Diagnosis

Phoropter: Custom LASIK Diagnosis
A phoropter is commonly used during an eye examination to measure an individual's refractive error and determine his or her eyeglass prescription.

When LASIK was first developed, the diagnostic process was very crude. Doctors would simply use a phoropter to determine the degree of the patient's near or farsightedness. As you can imagine, these early surgeries were not nearly as successful as those performed with today's more customizable LASIK procedures.

No two eyes the same
Much like snowflakes and fingerprints, each human eye is different, and each has a unique set of defects that must be corrected to improve vision. During custom LASIK, these imperfections are mapped out during the diagnostic process. In some procedures, a computer-guided laser then performs very precise surgical corrections.

Imperfections of the eye fall into two main categories:

  • Lower Order Aberrations (LOA) - imperfections related to the overall shape of the eye. These defects can cause nearsightedness, farsightedness, or astigmatism.

  • Higher Order Aberrations (HOA) - microscopic imperfections in the surface of the cornea. These can cause the quality of your vision to be poor, even if you see 20/20. Halos, starbursts, and ghosting are examples of vision problems caused by higher order aberrations.

How does custom LASIK diagnosis work?
The Wavefront system sends light into the eye, and evaluates the light as it is reflected back, generating a color-coded 3D map on the screen. This helps the surgeon determine if the patient is a good candidate for laser vision correction, and how the surgery should be performed.

There are several different laser systems that can be used in custom LASIK procedures including CustomCornea, Customvue, Allegretto Wave, and Zyoptix.

Advantages of custom LASIK
Wavefront-guided LASIK surgery produces more predictable results and crisper, clearer vision than conventional LASIK surgery. It can also be used to correct night-vision problems in some patients that are caused by higher order aberrations.

All LASIK surgery can increase the number of higher order aberrations in the eye, however, studies have shown that custom LASIK increases these aberrations less than conventional LASIK.

Is custom LASIK right for you?
If you are younger than 18, older than 40, have thin corneas, frequent vision changes, high intraocular pressure, high blood pressure, irregularly shaped corneas, large pupils, dry eye, eye herpes, corneal scarring, or have had a prior eye injury, custom LASIK may not be right for you. Visit your eye doctor to find out more about this and other treatment options.

Learn more about custom LASIK diagnosis with Wavefront technology on our forums!