Myopia, commonly known as nearsightedness, is a vision condition where distant objects appear blurry because the eyeball grows too long or the cornea has too much curvature. This elongation causes light to focus in front of the retina instead of directly on it. Atropine, a medication used in ophthalmology, is now used in diluted solutions to slow eye growth in children. The purpose of atropine myopia control is to reduce the rate of nearsightedness progression, aiming to limit the final prescription strength an individual may require.
How Atropine Works to Control Myopia
Atropine’s precise mechanism in slowing myopia progression is not fully understood, but theories focus on its impact on eye growth and retinal signaling. Myopia develops when the eyeball elongates, and atropine is believed to affect muscarinic receptors in the eye that regulate growth signals. It acts as a competitive antagonist, blocking muscarinic receptors from stimulation by the neurotransmitter acetylcholine.
Research suggests atropine may influence dopamine levels in the retina, a neurotransmitter associated with regulating eye growth. Higher dopamine levels may suppress signals that promote eyeball elongation. Atropine might also directly affect the sclera, the white outer layer of the eyeball, by interfering with scleral remodeling that accompanies progressive myopia. It may also inhibit the production of glycosaminoglycans within the scleral extracellular matrix, contributing to slower eye growth.
Who Can Benefit from Atropine Myopia Control
Atropine myopia control is primarily considered for children experiencing progressive nearsightedness. Factors indicating a child may be a suitable candidate include the age at which myopia first appears, the rate at which their prescription is worsening, and a family history of high myopia. This treatment is recommended for children whose myopia is actively progressing, meaning their glasses or contact lens prescription is consistently increasing.
An eye care professional’s assessment is necessary to determine if atropine is the right choice for a child. This evaluation considers the child’s overall eye health, the degree of their myopia, and how quickly their condition is advancing. For instance, children aged 6-10 years with myopia greater than -1.0 diopter and documented progression of at least -0.50 diopters per year are often considered for this treatment.
Administering Atropine Eye Drops
Atropine eye drops for myopia control are administered once daily, usually at bedtime. The concentrations used are low-dose, such as 0.01%, 0.025%, or 0.05%. While 0.01% atropine has shown efficacy, research indicates that 0.05% atropine may offer greater effectiveness in slowing myopia progression over two years.
Parents should ensure their hands are clean before administering the drops and avoid touching the bottle tip to the eye. The lower eyelid should be gently pulled down to create a small pouch, and the drop placed inside while the child looks up. Consistent daily use is important for the treatment to be effective, and the duration of treatment spans several years until the child’s eye growth stabilizes. Regular follow-up appointments monitor the child’s progress and adjust the treatment plan as needed.
Expected Outcomes and Efficacy
Clinical studies show that atropine is effective in slowing the progression of myopia. Low-dose atropine, particularly at 0.01%, can reduce myopia progression by approximately 34.2% in terms of spherical equivalent refraction and 22.0% in axial elongation over one year.
Higher concentrations, such as 0.05% atropine, have shown greater efficacy, with one study estimating a 64.5% reduction of spherical equivalent progression over two years. Atropine slows the progression of myopia; it does not cure nearsightedness or reverse existing vision impairment. The primary goal of treatment is to reduce the ultimate degree of myopia, which can lessen the risk of associated eye conditions later in life.
Managing Potential Side Effects
While low-dose atropine is generally well-tolerated, some side effects can occur. The most common ocular side effects include mild light sensitivity and occasional blurry near vision. These effects are minimal with low concentrations, as pupil dilation is small, around 1 mm for 0.025% and 0.05% atropine.
To manage light sensitivity, wearing sunglasses outdoors can provide comfort. If blurry near vision occurs, especially with slightly higher low doses, temporary reading glasses or progressive lenses may be recommended. Systemic side effects are rare with topical low-dose atropine because the eye absorbs only a small volume of the drops. However, if the drops pass through the tear ducts and are absorbed into the bloodstream, symptoms like dry mouth, dry eyes, or a rapid pulse may occur, but these are uncommon.