You may have heard about custom LASIK — also called “wavefront LASIK.” But did you know there is more than one type of wavefront LASK?
Most custom LASIK is wavefront-guided LASIK. The most popular laser platforms for wavefront-guided LASIK are AMO’s iLASIK and CustomVue excimer lasers.
Wavefront-guided LASIK is designed to detect and treat pre-existing higher-order aberrations (HOA) of the eye as well as correcting common refractive errors (nearsightedness, farsightedness and astigmatism).
But there is also something called wavefront-optimized LASIK.
The leading laser technology for wavefront-optimized LASIK is the Allegretto Wave Eye-Q excimer laser. The Allegretto Wave system was produced by the German company WaveLight AG and is now sold by Alcon.
Wavefront-optimized LASIK aims to correct refractive errors while maintaining the natural shape of the cornea to prevent inducing higher-order aberrations during the vision correction process. It doesn’t try to correct pre-existing higher-order aberrations.
So which is better: wavefront-guided LASIK or wavefront-optimized LASIK?
In the February 2010 issue of Review of Ophthalmology, several Allegretto Wave LASIK surgeons discuss the latest wavefront-optimized technology and compare it to the more popular wavefront-guided lasers.
Outcomes of wavefront-optimized vs. wavefront-guided laser vision correction
Surgeons who use the Allegretto Wave wavefront-optimized system say most LASIK candidates have relatively low amounts of pre-existing higher-order aberrations and therefore don’t require wavefront-guided laser treatments.
They also say research shows that wavefront-optimized treatments provide visual outcomes that are comparable (and sometimes better) than visual outcomes with wavefront-guided lasers.
In a study of 348 eyes that were randomly chosen to receive either wavefront-optimized or wavefront-guided laser vision correction, 94 percent of the wavefront-optimized eyes and 95 percent of the wavefront-guided eyes had uncorrected visual acuity (UCVA) of 20/20 or better three months after surgery.
In the same study, 70 percent of eyes receiving the wavefront-optimized treatment had UCVA of 20/16, compared with 63 percent of eyes receiving the wavefront-guided treatment.
Eyes with high amounts pre-existing higher-order aberrations (greater than 0.3 root mean square [RMS] values) did tend to have better visual outcomes after wavefront-guided LASIK, but less than 20 percent of patients had this level of pre-existing aberrations, according to the researchers.
Wavefront-optimized Eye-Q laser: Extremely fast for high corrections
The latest Allegretto Wave Eye-Q excimer laser for wavefront-optimized LASIK has a very fast pulse rate of 400 kHz, compared with excimer lasers approved for wavefront-guided LASIK that operate at frequencies of 200 kHz or lower.
The higher-rated Eye-Q laser produces a faster procedure, with potentially fewer complications and better outcomes, according to surgeons who use the system.
At 400 kHz, the Eye-Q laser can correct 1.00 diopter (D) of nearsightedness in about two seconds. This makes the procedure much faster and more comfortable for highly nearsighted patients, they say.
SOURCE: How to change your tune to Allegretto. Review of Ophthalmology. February, 2010.
Tags: Allegretto, excimer lasers, wavefront-guided, wavefront-optimized, WaveLight