WFG diagnostic capabilities take entire optical system into account
Advancements in wavefront-guided technology include improved resolution that provides not only better spot quality but also the ability to scan highly aberrated eyes that often did not produce treatable images using earlier technology, according to Edward E. Manche, MD.
Reviewed by Edward E. Manche, MD
The latest generation of wavefront-guided (WFG) LASIK instruments allows ophthalmologists to treat highly aberrated eyes in a single step. WFG ablation can treat aberrations of the entire eye, not just corneal aberrations, said Edward E. Manche, MD.
This new technology has five times the resolution of the previous wavefront sensor, explained Dr. Manche, director of cornea and refractive surgery, Byers Eye Institute, Palo Alto, CA, and professor of ophthalmology, Stanford University School of Medicine, Stanford, CA.
“You now have 210-μm resolution compared with the 400-um resolution with the previous-generation aberrometer, which allows you to successfully image and treat highly aberrated eyes, eyes with keratoconus, corneal scarring, and previous trauma that we could not effectively treat before,” he said. “WFG ablations provide excellent clinical outcomes for eyes with naturally occurring refractive error, and we can rehabilitate highly irregular corneas and correct refractive errors in one step.”
Latest WFG outcomes data
Dr. Manche reviewed published data from high-volume commercial settings treating low myopia, his own results in moderate myopia, and study results in highly aberrated eyes using a particular system (iDesign, Johnson & Johnson Vision/formerly Abbott).
WFG offers improved diagnostic capabilities that take the entire optical system into account, Dr. Manche explained. Most systems are based on Hartmann-Shack technology, although early systems included Tscherning aberrometry, and ray-tracing aberrometry has shown promise, he noted.
The first generation of WFG technology was introduced about 15 years ago, Dr. Manche noted. Both WFG and wavefront-optimized (WFO) technologies create ablations customized to each eye, but WFG is more highly personalized and customized to each eye.
The latest iDesign instrument utilizes more than 1,250 datapoints over a 7-mm wavefront compared with 240 datapoints over a 6-mm wavefront used by the previous wavefront technology. The improved resolution provides better spot quality and the ability to scan highly aberrated eyes that often did not produce treatable images using earlier technology, he noted.
The LASIK market is split between WFO and WFG systems in the United States, Dr. Manche continued.
Some clinicians may view WFG as more labor intensive. WFO requires only refraction and keratometry values, whereas WFG also requires aberrometry.
Dr. Manche noted that two excimer laser technologies (VISX CustomVue, Johnson & Johnson Vision; WaveLight Allegretto, Alcon Laboratories) are integrated into the workflow in his practice.
“I don’t see a real time difference in my clinical practice,” he said.
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