This is a common reason for consultations at Las Vegas Eye Institute. Here we attempt to discuss some of the key elements of a thorough examination for refractive surgery. Some of the things that we evaluate at our office you may already know, such as your glasses or contact lens prescription. However, you may not be aware of conditions like irregular corneal shape or subtle eye dryness. An evaluation at Las Vegas Eye Institute is the best way to find out about your LASIK candidacy.
What is your Refractive Error?
This is the most important question for helping to determine if you are a candidate for LASIK. The good news is that with modern LASER Vision correction technologies most patients presenting for refractive screening will be candidates for refractive surgery. At Las Vegas Eye institute the Visx iDesign 2.0 system is FDA approved for correction of myopia (nearsightedness), astigmatism, and hyperopia (farsightedness.)
The above video is a great primer on astigmatism and how it is treated.
Our Visx iDesign Laser is FDA approved for treatments up to 12D of nearsightedness; however, due to restraints on how much tissue we can safely remove, most surgeons will limit LASIK to corrections of -8.00 to -9.00 diopters. Our laser is approved to also correct up to 5 diopters of astigmatism when using its iDesign Wavefront guidance and as long as we feel that you are an appropriate candidate we can attempt to correct that full amount. Lastly, for people that are farsighted the Wavefront Guidance program allows corrections up to +4.00 diopters, but we generally try to limit our corrections to patients with +3.00 diopters or less. The reason for this is that Dr. Swanic has found with most LASER platforms, even including our advanced iDesign 2.0 system, it is difficult to successfully correct over +3.00 diopters and have it remain stable long term. We have had patients get excellent correction of +4.00 or even +5.00 diopters of farsightedness, but unfortunately we have seen it regress back to about +3.00 diopters over the first few years after original treatment.
The above video helps explain the condition of Hyperopia or Farsightedness.
Have you ever been told that you have any eye diseases?
One of the things that LASIK consults focus on is the detection of eye diseases that you may not even be aware that you have. The one that we focus most heavily on is Keratoconus. Our testing is focused on making sure that you don’t have keratoconus or a predisposition to developing keratoconus (this is referred to as forme fruste keratoconus.) People with Forme Fruste Keratoconus should not undergo LASIK eye surgery because it can lead to a condition called corneal ectasia.
The above video gives more information on the disease Keratoconus.
Subtle abnormalities of the eye can be detected by one of our advanced diagnostic devices. We actually use 2 different corneal topographic devices at Las Vegas Eye Institute for this purpose. The first is the infrared topography built into the iDesign 2.0 platform. Although you can’t see them, hundreds of infrared lights are reflected off of your cornea and create a precise map of your eye. This map is later used during your LASIK treatment to improve its accuracy but we also use this data to evaluate the shape of your eye for any subtle disease. Next, we use the Cassini topographer to which uses 679 multicolored LEDs to create a GPS like map of your corneal shape. This gives us incredible corneal detail to detect even the subtlest of disease.
Starting in November of 2019 we are excited to be adding epithelial thickness mapping with the Zeiss Cirrus 6000 OCT. Optical Coherence Tomography (OCT) is amazing Laser technology that scans your eye at 100,000 times per second to create a detailed map of your cornea. We have been using OCT technology for years at Las Vegas Eye Institute for corneal analysis prior to LASIK but we are proud to add detailed analysis of the corneal epithelium (the 50 micron surface layer of the eye). Studies have shown that subtle findings of early Keratoconus can be masked by our epithelium but with this technology we now have the capability to spot them wear other devices would have missed them. We are proud to be on the cutting edge at Las Vegas Eye Institute, all of this technology comes at a cost, but we are confident that you will agree that your vision is priceless.
Have you been told that you have dry eye? Do you have trouble wearing contact lenses?
Contacts can be rough on the eyes, especially in the dry Las Vegas heat. The good news is that even if your contacts bother your eyes this often does not mean that you have dry eye that would prevent you from undergoing LASIK or PRK. Dr. Swanic used to have extreme difficulty wearing contacts. In fact, he only wore glasses for the two years leading up to his PRK procedure because his eyes would turn very red after just two hours of contact lens wear. Fortunately, his eyes were carefully evaluated for signs of dryness (none were found) and the decision was made to proceed with PRK.
People with severe dry eye should not undergo LASIK as this is likely to make their dryness worse, maybe not permanently, but possibly for several months to a year. At Las Vegas Eye Institute all LASIK patients are evaluated for dryness preoperatively. If signs of dryness are found we will attempt to address them preoperatively. If we cannot get them under control adequate control then we will regretfully recommend avoiding Laser vision correction. For patients over the age of 40 they may still be a good candidate for Refractive Lens Exchange which is discussed elsewhere on our website.
I have more questions. How can I learn more?
We have lots of great information on our website covering LASIK, Cataract Surgery, and other treatment options on our website, but truly the best way to get your Laser vision correction questions answered is to come in for a complimentary LASIK screening exam.
By: Matthew Swanic M.D.
Cornea and Refractive Fellowship Trained Surgeon
Las Vegas Eye Institute