A new clinical trial has found that a common eye drop is a safe and effective way to slow the progression of nearsightedness in children. The finding may provide an easier way of treating the condition, which is expected to affect about 50% of the world’s population by 2050 and can lead to visual impairment later in life.
Nearsightedness – myopia – is a common condition in which objects that are close appear clearly, but far ones are blurry. It occurs when the eye’s shape causes the light rays that enter it to bend inaccurately. Instead of the light rays being focused on the retina at the back of the eye, they’re focused in front of it.
Myopia usually presents between the ages of six and 12, when a child’s eyes become abnormally elongated; that is, the eyeball is too long from front to back. Multifocal contact lenses or overnight vision correction lenses may slow elongation and, therefore, the progression of myopia. Still, no pharmaceutical products are approved in the US or Europe to treat the disease’s progression. Early-onset myopia is associated with complications later in life, such as myopic macular degeneration, retinal detachment, cataracts, and glaucoma.
Now, researchers from Ohio State University have found that a commonly used eye drop may effectively slow eye elongation in nearsighted children. They conducted a phase 3 clinical trial to assess the safety and effectiveness of two low-dose eye drop formulations containing atropine, the drug used to dilate the pupils before eye exams.
“The idea of keeping eyeballs smaller isn’t just so people’s glasses are thinner – it would also be so that in their 70s they don’t suffer visual impairment,” said Karla Zadnik, the study’s lead author.
The trial’s 489 participants were aged three to 16 and had myopia. They were assigned to one of three groups: treatment with a placebo, treatment with 0.01% atropine drops, and treatment with 0.02% atropine drops. Because currently available atropine preparations contain preservatives, the researchers used a pharmaceutical-grade preservative-free formulation that is under development as a myopia treatment.
The trial ran for three years and included measuring participants’ eye growth and their glasses prescription requirements. After being treated with one drop per eye at bedtime, the researchers found, compared to the placebo, atropine was more effective at slowing myopia progression. What they didn’t expect was that the 0.01% preparation would be more effective than the 0.02%. They found that while it was still better than the placebo, the 0.02% formulation produced inconsistent results.
“The 0.01% story is clearer and more obvious in terms of significantly slowing both the growth of the eye as well as then resulting in a lower glasses prescription,” Zadnik said.
The researchers found that both low-dose atropine preparations were well tolerated and safe. Few side effects were reported, but they included light sensitivity, allergic conjunctivitis, eye irritation, dilated pupils and blurred vision.
Safety and efficacy testing was Stage 1 of the trial, called CHAMP (Childhood Atropine for Myopia Progression). Stage 2 will involve the researchers evaluating how the eyes respond when treatment is concluded. The researchers say that, based on the results of Stage 1, atropine may be an appropriate treatment option for children with myopia progression.
“From a risk/benefit perspective, the efficacy and safety observed suggests that low-dose atropine may provide a treatment option for children aged three to 17 years with myopia progression, which may lead to less frequent or delayed change in glasses, progression to less severe correction, and potentially reduce long-term sequellae, which could lead to vision loss later in life,” the researchers said.
The study was published in the journal JAMA Ophthalmology.
Source: Ohio State University
