Until recently, excimer lasers have been programmed with standard refractive data to reshape the cornea. But a new technology, called wavefront analysis, is able to measure optical aberrations beyond what can be neutralized by subjective refraction. Laser manufactures are working hard to incorporate this technology into laser systems they anticipate will be capable of highly customized treatment that can make corrections for all optical aberrations. Some are hoping that within 5 to 10 years, wavefront-guided laser will enable people to achieve super vision 20/20 or 20/15.

The different between standard and custom LASIK might be compared to buying shoes. A standard factory-made shoe is selected by size and width, but a custom-made shoe relies on numerous measurements to create a perfect fit for each foot.

The location and depth of standard LASIK ablation is based on sphere, cylinder and axis, the measurements so successfully used to create corrective lenses. If customized treatment is desired, there are 2 options for more detailed measurements:

Wavefront analysis -- provides 4 to 100 numbers that identify aberrations found throughout the entire optical system.

 

Corneal topography -- provides a topographical map of surface aberrations based on 4000 to 6000 points of measurement.

 

If abnormalities that cause focusing problems are known to be on the surface of the cornea, we believe corneal topography provides better guidance for custom LASIK. However, when aberrations arise from composite of the optical media, wavefront analysis is a more accurate measurement to guide customized treatment.

 

New Lens -- An implantable contact lens (ICL) that has been widely used in Europe was recently approved for use in the United States. From 1997 to 2003, American surgeons participating in a clinical study implanted this lens in more than 500 patients. Results showed over 84% achieved 20/40 vision or better without the use of glasses or contact lenses.

How They Work -- Unlike lens implants that replace the eye's lens after cataract surgery, ICLs are placed in front of the natural lens -- where thy rest without needing any care. In this position, they work in combination with the eye's lens to add more focusing power. ICLs offer dramatic results that are quite predictable.

Range of Correction -- ICLs can be used to correct nearsightedness between -5 and -20 diopters.

Remove Later in Life -- With age, most people develop cataracts -- a clouding of he eye's natural lens. The solution for a cataract is to surgically remove the clouded lens and replace it with a lens implant that is positioned behind the iris. During this procedure, an ICL that is in front of the iris would need to be removed. Although cataracts may begin to form earlier in life, and surgery is occasionally required for people in their 50s, the average age for cataract surgery in the USA is about 72 years.

Lens Replacement -- Refractive lens exchange (RLE) involves removing and exchanging the eye's natural lens with an artificial lens implant. This is done to correct moderate to high degrees of near and farsightedness. For each eye, the surgeon selects a lens implant that will enable the eye to focus as normally as possible. The results of RLE offer dramatic and quite predictable outcomes.

Cataracts Later in Life -- With age, most people develop cataracts -- a clouding of the eye's natural lens. Although cataracts may begin to form while people are in their 50s, the average age for cataract surgery is the USA is about 72 years. The solution is surgical removal of the clouded lens and replacement with a lens implant. Having RLE earlier in life prevents the possibility of cataracts.