Amblyopia (Lazy Eye) Treatment Options
Often described in non-clinical terms as a lazy eye, amblyopia affects about 2 to 3 in every 100 children. In fact, it is the most common cause of visual impairment in children, according to the National Eye Institute. And if left untreated, the disease persists in adults.
Amblyopia itself is not the result of a lazy eye. The vision problem is not just an eye problem either. “Amblyopia is the medical term used when the vision in one eye is reduced because it is not working properly with the brain,” notes the NEI. “The eye itself looks normal, but for various reasons the brain favors the other eye.”
Even when the underlying vision problem is corrected – for example, myopia with glasses or cataract with surgery – the brain will continue to promote worldview through the other eye. Essentially, in such cases, “the brain turned off with one eye, ”says Dr. Christopher Gappy, assistant professor of ophthalmology at the Kellogg Eye Center at the University of Michigan in Ann Arbor.
Amblyopia is closely related to the early development of the brain and its connection with the eyes. For this reason, experts say, it is essential to treat the problem in children as soon as it is detected. Treatment that stimulates vision in the weaker eye can improve the development of the parts of the brain involved in seeing. Even in adults, the brain may be able to adapt somewhat to “activate” the weak eye if, for example, an accident drastically alters vision or causes blindness in the strong eye. However, the effectiveness of treatment usually drops dramatically as children grow older.
The causes of amblyopia generally fall into three categories:
- Anisometropia: uneven refractive power in the eyes – eg one is nearsighted, one farsighted.
- Strabismus: A person cannot align their eyes, so they can point in different directions.
- An eye problem such as a cataract, a droopy eyelid, or a scarred cornea.
As a result, amblyopia can be called refractive amblyopia (which is caused by anisometropia), strabic amblyopia or deprivation amblyopia, respectively.
Anisometropia is the most common cause of amblyopia in the United States, notes Dr. Alejandra de Alba Campomanes, professor of ophthalmology at UCSF School of Medicine and chief of pediatric ophthalmology at UCSF Benioff Children’s Hospitals . Strabismus is the next most common, and children with anisometropia often have strabismus as well.
In fact, the term “lazy eye” itself is sometimes used by some patients to describe a type of strabismus, “when the eyes are not perfectly aligned and one eye tends to drift – for example, to drift” , explains de Alba Campomanes. “The layman term for amblyopia is sometimes lazy eye. But lazy eye is a confusing term because different people use it differently. Doctors generally refrain from using it except to clarify what patients and parents mean when they describe a vision or eye problem this way.
Sometimes people use the term to refer to a droopy eyelid. In other cases, “lazy eye is a term people use to describe an amblyopic eye.” But really, she and other experts point out, it’s a misnomer to think that vision problems in this eye are the result of the eye alone. “It is the connection between the eye and the brain that is faulty, it is not really the eye that does not do a good job”, explains de Alba Campomanes.
All things considered, clinicians say the important thing is not to hang on to the language but to understand what is going on and deal with the problem quickly. Ophthalmologists say that if parents are concerned that their child has a “lazy eye” – or whatever it is – they should discuss their concerns with the child’s doctor immediately. Although early vision tests can detect some problems, parents are often the first to notice problems like strabismus and amblyopia.
In addition to seeing a child’s primary care provider, a referral to a pediatric ophthalmologist – an ophthalmologist or optometrist who specializes in caring for young children – may also be warranted for a closer look. This includes assessing the child to determine if vision differs from one eye to the other, if there are any underlying eye health issues, and to check for other issues, such as if one eye is “wandering”. Or does not align with the other.
Before amblyopia can be treated, ophthalmologists say the underlying causes need to be treated. So that may mean getting glasses with different prescriptions in each lens to correct anisometropia. Approaches to treating strabismus include special glasses with thicker prism lenses on one side or the other and eye muscle surgery to improve alignment.
Once the cause of amblyopia has been treated, the focus is on rehabilitating the eye-brain connection, so children can regain full vision. “It’s kind of like a competition between the two eyes,” says Dr. William Madigan, acting division chief for ophthalmology at the Children’s National Health System in Washington. “If they both function equally well, they each get their section of their visual cortex, and it develops into normal binocular vision.”
If one eye has the advantage, however – as is the case with amblyopia – it sort of occupies the area of the brain that should be shared between the eyes; the brain-eye connection is therefore only strong for this dominant eye. For this reason, the most common and effective solution for amblyopia is usually to cover the strong or “good” eye with a patch, according to experts. This forces the brain to work with the weaker eye and improve that connection, which ultimately improves vision in that eye.
Research indicates that the brain retains some plasticity – that is, it always has the ability to change – even after development into adulthood. Even so, experts say the critical window to most effectively treat amblyopia is between 0 and 9 years. After that, the patch may help, but it’s much less likely to precipitate the kind of dramatic turnaround that can be found in young children.
“Treatment is most effective when started earlier in life,” says de Alba Campomanes. “We believe the window of opportunity for treatment closes at some point in late childhood or early adolescence – there is some variability.”
One of the most difficult aspects of treating amblyopia – besides the child’s initial annoyance of having their eye well covered – is the amount of time spent. For younger patients, including toddlers, depending on the severity of the problem, the patch may be done for a shorter duration, while for children 7 or 8 years old, it usually takes longer to see. change.
So, although there is no specific range, some children may need to wear a patch for two hours a day and others for six to eight hours a day or more. This can be done over a period of a few years for younger and older patients – although the total time it takes will vary depending on the case as well. And accommodations can be made, such as not patching during school, to try to reduce its impact on a child’s life.
Some patches come with an adhesive, so they can be applied directly to the face and stay snug. However, in children who wish to remove the patch from their eye or who are not old enough to follow the instructions, eye drops can be used instead to obscure the vision of the strong eye.
Most often, atropine drops are applied daily by parents. While safe from a vision standpoint, experts say the drug still has side effects, especially if given more generously than intended. “If you have too much atropine… you sweat profusely, you’ll turn red and (you) sometimes even hallucinate,” Madigan says. Of course, this worries parents. But he says if parents are careful how they use it, kids won’t get too high a dose.
For some children who are more sensitive to atropine and need it less to blur vision in the strong eye, an ointment formulation is recommended because it is not absorbed as well, so a child is not susceptible. to have too high a dose. To apply it, a parent pulls the child’s lower eyelid down and pops out a small bead the length of a sharp pencil point, Madigan explains. Once in this pocket, the body temperature melts the ointment and spreads it so that it is absorbed by the eye.
Experts say that temporary blurring of vision in the strong eye – whether using a physical patch or the pharmaceutical equivalent of the patch – is the research-backed first choice for treating children with amblyopia.
Additionally, some ophthalmologists may recommend vision therapy – or what is also called eye training or vision exercises. It can be as simple as having a child perform visually demanding tasks while wearing a patch, like coloring or playing a video game, says de Alba Campomanes.
For some forms of strabismus, there is little scientific research that shows vision therapy can help, she says. “But there haven’t really been a lot of rigorous studies.”
In addition, vision therapy is generally not covered by insurance. Madigan notes that some forms of visual training have been around for decades, and eye exercises were even tried in the mid-20th century. “None of them succeeded. If they had been successful, we would have been doing them for the past 40 years, ”he says.
It remains to be seen whether modern iterations, such as those that involve playing specially designed video games and wearing 3D glasses to try and train the eyes to work together, will receive more research support. In the meantime, although they can help in addition to the patch, de Alba Campomanes does not recommend them as the only treatment for amblyopia. And most experts say the stronger eye should be darkened to encourage the brain to use the weaker eye. “I have a feeling that eye exercises alone wouldn’t correct amblyopia,” she says.
To ensure children have the best chance of being treated effectively, experts say early detection of amblyopia is crucial. Parents need to make sure children are assessed promptly if they are concerned that their eyes are not working together – or that one of them is dominant. This way, a proper diagnosis can be made and treatment can be started without delay if a child is suffering from amblyopia or some other vision problem.
“They should start with their pediatrician,” says de Alba Campomanes. “But if their concern persists, they should see a pediatric eye care provider.” An ophthalmologist should be able to determine if a child has amblyopia and advise on treatment options to correct it.