Vision of the Future: Custom Corneas

NASA technology that allows the Hubble telescope to focus on distant stars now offers LASIK eye surgery patients customized options for fine-tuned night vision, superior image contrast and sight even beyond 20/20.

Approved by the U.S. Food and Drug Administration in 2001, wavefront technology is the newest LASIK innovation that ophthalmologists are using not only to correct eyesight, but also to peer into the physical structure of patients' eyes and locate the exact sources of their vision problems.

"We already tailor eyesight to patient goals," says Dr. Bradley Randleman, associate professor of Ophthalmology at Emory Eye Center in Atlanta. "We're getting more and more advanced with tailoring our laser treatment to the specific aberrations in the pattern of the cornea so we can best maximize the quality of vision."

Since wavefront imaging can diagnose more subtle corneal imperfections, the technology has also expanded the LASIK treatment zone beyond myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. Patients with more complex vision problems, such as irregular astigmatism or complications from past refractive surgeries, are now viable candidates.

Studies have also found that wavefront treatments, which generally cost more than conventional LASIK, can minimize potential side effects from refractive surgery, including glare, diminished night vision and blurriness.

"All of these (technologies) are really geared toward bridging the gap from initial LASIK treatments," Randleman notes.

Wavefront sensing technology charts how light travels to and from the lens, cornea and retina as a series of overlapping sheets, or wavefronts. Flaws in the corneal tissue cause those wavefronts to wrinkle and scatter incorrectly.

A device called a wavefront aberrometer records wavefront deviations that occur in the corneal tissue and plots them like a three-dimensional map.

Depending on the type of corneal defects, along with the age and vision needs of LASIK patients, ophthalmologists can input the wavefront data into a wavefront-guided or wavefront-optimized laser to perform "custom" LASIK surgery.

"Now using custom lasers, two people with the exact same prescription generally won't get the same laser treatment." says Dr. Roy Rubinfeld, a Washington, D.C., eye surgeon and clinical correspondent for the American Academy of Ophthalmology.

For instance, with older patients who spend most of their time indoors, Rubinfeld might adjust their near vision to a finer degree than outdoorsy types who would benefit from sharper distance and intermediate vision.

"Most golfers, I try to give them better than 20/20 in both eyes," Rubinfeld told Discovery News.

Custom eyesight might sound like a novel development, but ophthalmologists are also quick to point out that matching vision correction to patients' lifestyles has long been an integral part of the LASIK process.

Wavefront technology merely provides more specific optical data about which lasers and techniques are best suited to correcting vision problems, whether that means using conventional or wavefront lasers.

"We're refining our screening to match each person with the best treatment for them," Randleman from Emory Eye Center explains. "In a way, it's akin to shopping for clothing. Whatever size you are, you know that not every brand in every store in that specific number will fit you."

Likewise, while custom LASIK can produce impressive results, patients should seek out well-trained, capable ophthalmologists rather than just springing for a wallet-friendly deal on a wavefront treatment.

"Don't go looking for a specific technology because the best surgeons will know what that is and have it," Dr. Rubinfeld says.