Researchers are investigating a very different approach to vision correction. Instead of removing corneal tissue with a laser, the experimental technique temporarily makes the cornea flexible enough to be reshaped.

Early experiments using rabbit eye tissue suggest the method could correct the cornea’s shape in about a minute. It requires no incisions and may use a much simpler device than LASIK. However, the research remains in its earliest stages and has not yet been tested in living human eyes.

Why the cornea’s shape matters for vision

The cornea is the transparent, dome-shaped surface at the front of the eye. It helps focus incoming light onto the retina, the light-sensitive tissue at the back of the eye. The retina converts that light into signals that the brain interprets as images.

When the cornea is not curved correctly, light may not focus properly. This can cause refractive errors such as myopia, also known as nearsightedness, in which distant objects appear blurry.

LASIK corrects these problems by using a specialized laser to remove and reshape precise amounts of corneal tissue. Although LASIK is widely used and generally considered safe, it permanently removes tissue and can involve side effects and other risks.

Michael Hill, a chemistry professor at Occidental College, describes the limitation this way: “LASIK is just a fancy way of doing traditional surgery. It’s still just sculpting the tissue, and it’s just sculpting it with a laser.”

That led the researchers to ask a different question: Is it possible to reshape the cornea without cutting it?

How electromechanical remolding could reshape the eye

Hill and co-researcher Brian Wong are investigating a technique called electromechanical remolding, or EMR. Rather than physically removing tissue, EMR uses small electrical potentials to temporarily change the chemical environment inside the tissue.

“The whole effect was discovered by chance,” Wong explains. “I looked at biological tissues as moldable materials and discovered the entire process of chemical modification.”

The technique relies on the chemistry that helps biological tissues maintain their shape.

The cornea contains large amounts of collagen, a structural protein also found in skin, cartilage, tendons and other tissues. Within collagen-rich tissues, electrically charged components attract one another and help hold the structure together.

These tissues also contain substantial amounts of water. Applying an electrical potential can change the pH, which measures how acidic or basic a substance is. Lowering the pH makes the tissue more acidic and temporarily weakens some of the electrical attractions that help keep its structure rigid.

During this brief period, the tissue is more likely to reform. When the pH returns to normal, those interactions are restored, helping the tissue maintain its new shape.

Researchers have previously used EMR to reshape cartilage-rich rabbit ears and modify scars and skin in pigs. The cornea was an especially interesting target because its precise curvature determines how effectively the eye focuses light.

A platinum “contact lens” acts as a corneal mold

For the new experiment, the researchers created a special platinum “contact lens” designed to serve as a mold for the desired corneal shape.

They placed the lens over a rabbit eyeball soaked in saline to mimic natural tears. Because platinum conducts electricity, the lens also functioned as an electrode. When the researchers applied a small electrical potential, it produced a carefully controlled change in the pH inside the cornea.

Within about one minute, the cornea’s curvature changed to match the shape of the platinum lens.

This is roughly comparable to the time required for the laser portion of LASIK. Unlike LASIK, however, the experimental EMR method requires no incision and may rely on simpler, less expensive equipment.

Early tests corrected myopia-like focusing changes

The researchers tested the method on the eyes of 12 rabbits. Ten eyes were treated to model myopia.

In all 10 of these “myopic” eyes, EMR changed the cornea enough to achieve the intended focusing power. In practical terms, a similar optical change could improve visual acuity if the effect can eventually be reproduced safely in living eyes.

Importantly, the eye cells treated in the experiment survived the procedure. The researchers achieved this by carefully controlling the pH gradient, producing enough chemical change to reshape the cornea without causing excessive damage.

Potential treatment for corneal clouding

The experiment also suggested possible uses beyond routine vision correction.

In separate tests, the researchers found that EMR may be able to reverse some clouding in the cornea caused by chemicals. This condition is currently treatable only with a complete corneal transplant.

If future studies confirm these findings, EMR could have applications beyond correcting common refractive errors.

Why EMR is not yet a replacement for LASIK

Despite the promising early results, researchers emphasize that EMR is still in a very early stage of development.

So far, the vision-correction experiments have been performed on removed rabbit eyes rather than living animals. The next major step is what Wong calls “a long march through detailed and precise animal studies,” including tests on live rabbits.

Researchers must also determine which refractive errors EMR can correct. These may include myopia, farsightedness and astigmatism, which are common conditions associated with an irregularly shaped cornea or lens.

Before the approach can be widely tested in people, scientists will need to answer many additional questions, including how stable the reshaped cornea remains over time and whether living eyes experience repeated or long-term effects.

Progress has also been slowed by uncertainty surrounding the team’s scientific funding.

“There’s a long way to go from what we’ve done to the clinic, but once we get there, this technology is widely applicable, much cheaper, and potentially even reversible,” Hill concludes.

The study was funded by the National Eye Institute of the National Institutes of Health and the John Stauffer Charitable Trust.