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Myopia is expected to become a leading cause of permanent blindness around the world.1
Myopia is a disease-not a refractive error anymore, says Pamela Lowe, OD, FAAO, at Vision Expo East in New York City.
“We need to talk about the science behind starting myopia management protocols,” she says.
In today’s age of practice, all healthcare practicioners should be on the same primary-care model-including ODs.
“Dry eye, age-related macular degeneration (AMD), and myopia is where ODs need to take the lead,” Dr. Lowe says.
Related: Treating and diagnosing myopia
While ODs know a patient is important, Dr. Lowe says that over the years she has begun giving her patients the “why” behind what she does to treat them.
“It’s critical,” she says. “Anything I’m doing for patients-they need to know the ‘why.’”
As a refractive code, myopia is any refractive error > -0.50 D. High myopia is classified as a refractive error with a spherical > -5.00 D.
By 2050 there will be an estimated 5 billion myopes in the world-with high myopes expected to account for 1 billion of that amount.1
Patients who are high myopes typically also have the following ocular conditions:
• Cataract (early onset)
• Retinal detachment
• Myopic macular degeneration
Knowing the higher risk these patients have for such conditions enables ODs to slow myopia progression, Dr. Lowe says.
“We need to be talking to our patients more comprehensively about this,” she says.
Related: Know the legal aspects of myopia control
Some of the major risk factors associated with myopia progression include:
• Family history
• Age of onset
• Visual efficiency
• Gender (possibly)
Dr. Lowe is a member of the newly established myopia control task force formed by Essilor. The 14-OD member group is seeking to establish a new protocol for treating and managing myopia.
“We’re trying to educate the public,” Dr. Lowe says.
Related: Essilor forms task force to combat rise of myopia
When looking at family history, Dr. Lowe categorizes patients into three areas: low risk, medium risk, and high risk. A pediatric patient’s chances of becoming myopic increases when one or both parents are myopes.
Epidemic proportions in Asia-China, Japan, South Korea, Singapore-all face high risks of developing myopia due to genetics.
Age of onset
“The younger you become myopic, the greater the chance you will become more myopic during formative years,” Dr. Lowe says.
Children with age of onset at age 7 or younger face the highest risk of high myopia progression, while 8- to 15-year-olds pose a more moderate risk. Once a child is in high school and older, the risk of myopia progression is induced more by the environment rather than the age he is.2
The amount of time spent outdoors is more beneficial the younger a child is.2,3
More outdoor time can delay the onset of myopia, Dr. Lowe says.
• 2.5 hours per day -> low myopia risk
• 1.5 to 2.5 hours per day -> medium myopia risk
• 0 to 1.5 hours per day -> high myopia risk
Conversely, more time spent indoors conducting close-vision tasks has been closely tied to a higher risk for myopia development.3,4
• 0 to 2 hours per day -> low risk
• 2 to 3 hours per day -> medium risk
• 3+ hours per day -> high risk
It’s all about working distance, Dr. Lowe says. While adults typically keep close-vision distance to about 40 cm, kids often bring objects closer to their faces.
“If it’s less than 25 cm, the risk is greater - even for short periods of time,” Dr. Lowe says.
Related: How hyperopes differ from myopes
Watch those kids who don’t have as much hyperopia as they should, Dr. Lowe advises. If the children are esophoric or experience a high lag of accommodation, ODs are finding that those binocular vision disorders are putting them at a greater risk for becoming progressively myopic.
“So look at your binocular vision exam-it’s important,” she says.
Does gender matter? The jury is still out on that, Dr. Lowe says.
Some studies have shown females to appear to have a greater myopic progression. However, these results could have been skewed by the study population.5
Be mindful of transgender pediatric patients, Dr. Lowe warns. Most members of this population are traditionally adults by the time they determine their preferred gender.
Because the attempted suicide rate is so high in transgenders - nearly 40 percent6- pediatric specialists are now available for younger patients who identify early on to help with stopping puberty. When the transgender patients' bodies match their identities, they are happier and avoid many social stigmas. This can reduce the challenges of abuse and discrimination that may lead to depression and sucide attempts.
Related: Examining 7 options to control myopiaIneffective treatments
Methods previously thought to help in preventing myopia progress include:
• Single-vision (SV) spectacles
• SV alignment rigid gas permeable (RGP) contact lenses
• Multifocal spectacles
SV alignment RGP lenses were once prescribed so patients’ glasses thickness wouldn’t change as quickly over time. While this may help a patient for the moment, her vision will immediately revert back when the lenses are removed.
“It does nothing to help the axial length of the eye to stimulate it not to grow,” Dr. Lowe says.
Related: Gas permeable contact lenses-special or not?
Dr. Lowe singled out three treatment options effective in reducing the risk for myopia:
• Low-dose atropine
• Distance center, multifocal soft contact lenses
The mechanism of action of atropine below 0.1% is not yet understood but has had effective results when used, Dr. Lowe says. Refractive error is reduced, particularly versus axial length.
Compounded low doses of atropine have been found to have minimal effects and maximize the safety of a pediatric patient.
“It will help with lack of near-blur and intolerance for bright lights,” Dr. Lowe says.7
Ideal candidates for this treatment include pediatric patients with a level of immaturity, pediatric patients with parents unmotivated to enforce application, and patients with an intolerance to contact lens wear.
The higher the concentrated dose of atropine, the larger the effect on axial elongation, Dr. Lowe says.
Related: Considering myopia control
Distance center, multifocal soft lenses
These lenses may take strain off patients with a lack of accommodation or vergence problem but mainly treat myopia progression by creating a peripheral reteinal defocus, which signals the brain to tell the eye not to grow.
Ideal patients for this treatment include motivated patients or motivated parents of pediatric patients and patients with no to low levels of cylinder.
The benefits of a soft or hybrid lens includes a comfortable fitting and some availability as a single-use lens. However, risks associated with these lenses involve the potential for aberrations from the multifocal design, according to Dr. Lowe.
“We’re putting a multifocal lens on a non-presbyopic eye, so some can be sensitive to aberrations,” she says.
Dr. Lowe says that 98 percent of patients do not clean their contact lenses appropriately.8 Improper care of reusable lenses put patients at risk. Switching to daily disposable contact lenses can help avoid such complications.
She recommends a few fitting tips for these lenses:
• Spherical equivalent (SE) distance
• Start with highest add
Keep in mind pediatric patients wearing distance-center soft lenses are those with lower cylinder, Dr. Lowe says.
“You want to create that peripheral defocus as much as you can-so you start with the +2.50 D add.”
Based on how a patient is seeing, an OD might want to go up a click or two in distance correction, Dr. Lowe says.
“Do not change the add,” she warns. “Keep that the same because it is helping with maximum peripheral defocus. Wait to see how the patient responds.”
Whether patients are wearing a daily or reusable contact lens, ODs will want to see them back in the office within a week.
“I assess the comfort and fit, just as with any other lens,” she says. “Address any distance blurs-especially the older a child is.”
If a patient is still not seeing clearer when the prescription is more minused by a click or two, Dr. Lowe says it’s an indicator of too many aberrations for that patient’s visual system. In this case, she would go back to the patient’s original SE, refrain from putting more minus in, then take the add down from +2.50 to 2.00D.
Related: Spectacles offer relief for headaches, ocular symptoms
Similar to a distance-center soft contact lens, orthokeratology (ortho-k) uses a rigid lens with reverse geometry to flatten and redistribute the center corneal epithelium, changing the optics and creating optics that put a peripheral myopic defocus on the retina to help the eye. While the treatment reduces axial length most effectively, refractive error cannot be measured unless the patient stops lens wear and "washes out," Dr. Lowe says.
“It's hard to track a patient’s refractive status; with ortho-k it's all about axial length-not progressing and good daytime vision,” Dr. Lowe says. “But with distance-center soft multifocal lens patients-when they come in every year- you can see that they’re not getting more myopic.”
The best candidates for this type of lens are motivated patients (or motivated parents of pediatric patients) with mid-cylinder astigmatism.
Ortho-k benefits allow patients to be spectacle-free and contact lens-free throughout the day. This type of lens is excellent for athletes, especially swimmers Dr. Lowe says.
Risks associated with theses lenses are the potential for general improper lens care and overnight complications. However, the dangers are no more serious than those assosciated with sleeping in any other contact lenses; they have a good safety profile, Dr. Lowe says.
Related: Fitting ortho-k contact lenses
How it works
With ortho-k, reverse geometry uses the rigid contact lens to flatten the center of the cornea-But instead of a multifocal, the ortho-k design creates that same peripheral defocus, according to Dr. Lowe.
“Ortho-k and distance-center multifocal lenses are about equal in success for long-term myopia progression, Dr. Lowe says, “but ortho-k can be a more effective and efficient way for the patient to be contact lens and spectacle-free most of the day.”
Because advanced technology is necessary for ortho-k, Dr. Lowe says investing in a topographer is a must.
“You need to track the epithelium being moved and the flattening of that central fitting zone,” she says. “It has to be tracked at a higher level.”
More patient visits are essential with ortho-k fittings.
“When patients sleep in those lenses, you have to see them the next morning, then at one week, one month, three months, and six months,” Dr. Lowe says. “So if the patient is having challenges, it’s easier to track and orrect.”
Treating based on age
No patient’s myopia diagnosis is the same. With this in mind, Dr. Lowe works on a case-by-case basis.
“The younger the child us, the more impactful I know I can be. Just like with any disease, if you catch it ahead of time-the better,” she says.
Three forms of treatments leave room to provide patients with options, according to Dr. Lowe.
“If a patient is against contact lenses, at least I have the low-dose atropine in my toolbox. Then there are the two contact lens options in soft and rigid,” she says âCurrent studies are looking into the additive effect atropoine may play with soft multifocal use.
Before a child becomes myopic it is essential to discuss lifestyle adjustments that can deley onset. When myopia does start, consider the child’s age and the amount of myopia, and then talk about the three options and what will fit best for that patient's lifestyle needs, Dr. Lowe recommends.
It is important to give all options and start treatment in a timely fashion to save vision well into adulthood.
Read more by Alex Delaney-Gesing
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