UAB Medicine News


Attacking the Myopia Epidemic: A Boom in the Research Community

Rafael Grytz, PhD, Assistant Professor in the Department of Ophthalmology, was awarded a five-year R01 grant from the National Eye Institute to explore the underlying cause of myopia, the most common refractive error of the eye. Myopia, or nearsightedness, makes close objects appear clearly, but distant objects appear blurry. It affects nearly 40 percent of the U.S. population, and the prevalence of this diagnosis is rapidly growing around the globe.

The National Eye Institute released a recent study that examined the prevalence of myopia within certain timeframes: 1971 to 1972 and 1999 to 2004. The study found that an estimated 25 percent of the population, ages 12-54, had myopia between 1971 and 1972. This percentage increased to a staggering 66 percent between 1999-2004. During this time, myopia rose from 30 to 80 percent in Americans of European descent and an exorbitant 100 percent in African Americans. By some estimates, one-third of the world’s population could be affected by myopia at the end of this decade.

With myopia, the eye increases in size beyond normal levels and becomes too long for its own optical system. This means that the lens of the eye focuses light from far objects slightly in front of the retina, rather than directly on it. In severe cases, the eyeball elongates rapidly and causes high levels of myopia. This elongation process puts the eye at risk for blinding eye diseases such as retinal detachment, macular degeneration, and glaucoma. Progressive myopia is one of the leading causes of blindness worldwide. Glasses, contact lenses, and refractive surgery can help to visually correct myopia, but they do not address the underlying cause, the elongation of the eyeball, and they don’t reduce the risk to blinding ocular comorbidities. This threat has prompted a rise in the research community to elucidate the mechanisms behind myopia.

“The rate of myopia diagnoses is dramatically increasing, and we don’t know why. We need to do everything we can to prepare for the future,” says Grytz. “A person’s risk for debilitating vision-related health issues significantly increases with myopia. As a researcher, I know that the work we do now can prevent these types of devastating effects for people suffering from myopia and blinding ocular comorbidities in the future.”

With this grant, Grytz hopes to fight myopia using a two-fold approach. First, he will focus on how the eye becomes elongated in myopia, specifically focusing on the remodeling of the sclera. Scleral remodeling determines the final size of the eye. During childhood, the eye uses a visual feedback mechanism to try to match the size of the eye to its optical system by altering scleral remodeling. The sclera is known as the white, outer layer of the eye and is made out of collagen fibers, the toughest protein in the human body. Grytz hypothesizes that microdeformations between these collagen fibers underlie scleral remodeling. Grytz is exploring this remodeling process to learn how the eye adapts its eye size. He argues that “once we fully understand this remodeling process, we can develop new and effective treatment options to control myopia in every patient.”

The second step of his research is to control myopia through slowing sclera remodeling. Every eye has collagen crosslinks that connect the collagen fibers of the sclera with each other. Grytz believes that these crosslinks can prevent the micro-deformations that underlie scleral remodeling in myopia. Collagen crosslinks naturally accumulate as we age but can be incorporated artificially. Grytz proposes to inhibit scleral remodeling and progressive myopia by artificially crosslinking the sclera. Grytz believes that scleral crosslinking can become a feasible treatment option for controlling the most severe cases of myopia, where currently no good treatment option exists. Crosslinking has been applied to the cornea and successfully used to control keratoconus for over ten years, but this method has not yet been established for the sclera or myopia control.

Scleral remodeling is a rather slow process and the underlying micro-deformations take place over days, months, or years. No researcher has been able to see these micro-deformations because they take place over such a lengthy period of time. Grytz is partnering with the UAB High Resolution Imaging Facility to use their advanced microscope to induce artificial markers into the micro-structure of living scleras. Grytz’s laboratory has developed an organ culture system to image these markers as the sclera remodels over a period of days. Through partnership with the UAB High Resolution Imaging Facility, Grytz now has the ability to quantify micro-deformations in living tissues of the sclera, which has never been done before. If Grytz can uncover some of the fundamental mechanisms behind scleral remodeling in myopia, he can then look toward developing new treatments.

“There are things we can do to help children and young adults fight myopia. For instance, exposure to sunlight for two hours a day helps prevent myopia. However, at the rate this diagnosis is increasing, these tactics aren’t enough anymore. Researchers need to find the root cause and mechanisms driving this myopia increase. If we can stop myopia from forming at the most elementary level, we would have the ability to attack it at all fronts. My five-year, fully funded R01 grant will help the scientific community get closer to this goal,” says Grytz.

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