1. Types of Myopia Control
There are four widely accepted types of myopia control treatments: Orthokeratology (OrthoK aka CRT), Atropine eye drops, Distance-Center Multifocal Contact Lenses and in some cases Bifocal or Multifocal Eyeglasses. Optometrists throughout the country use methods based on patient age, prescription and need, sometimes combining methods for maximum impact. There is a lot of bad information out there, and recommendations are made for methods that actually may INCREASE myopia such as “undercorrection”, where the doctor provides a lower prescription than needed.
2. Spectacle Lenses: Bifocal and Multifocal Eyeglasses
In some children with certain eye-muscle positioning known as Esophoria, studies have shown that wearing a different prescription for distance and near is helpful. This is usually achieved in Bifocal or Multifocal eyeglass lenses. Bifocals have shown to be more effective in some studies and preference has been given for bifocals where the line is placed at the lower margin of the pupil of the eye. For those parents with children with the Esophoria who prefer not to have the children where contacts or use eyedrops or are too young this method has been shown to help in some studies.
3. SOFT CONTACT LENS For MYOPIA CONTROL
Distance Center Multifocal Soft Contact Lenses , annular or EDOF (extended depth of focus) are worn precisely the same as regular soft contact lenses. An optical “trick” in the center of the lens has been shown in several studies to slow down the progression of myopia more effectively than orthokeratology or atropine drops. This method is rapidly gaining in popularity. At this writing there are only two brands of these lenses. Your doctor can help determine which brand might be best for you.
Soft multifocal lenses offered as daily disposable are the easiest for a child to insert and remove, increased comfort of wear throughout the day, encourages proper hygiene and safety while affording the child optimized vision and myopia control.
Distance Center Multifocal Soft Contact Lenses
Distance Center Multifocal Soft Contact Lenses are worn precisely the same as regular soft contact lenses. An optical “trick” in the center of the lens has been shown in several studies to slow down the progression of myopia. This method is rapidly gaining in popularity. At this writing there are only two brands of these lenses. Your doctor can help determine which brand might be best for you.
A distance-center multifocal soft contact lens may be the best place to start because it can result in 50% reduction in the progression of myopia and a 29% re-duction in axial elongation, suggesting the potential for soft multifocal contact lens myopia control.
Two designs from CooperVision, the Proclear ®and Biofinity® Multifocal, allow for a distance zone of 75% of the child’s average pupil. The peripheral region of the lenses, which progress to intermediate and near plus power, refocus the image shell for the paravisual axis rays.
This allows for sustained myopic defocus (refocusing of the image shell) and can slow myopia progression without com-promising visual function—even when presented to the retina simultaneously with a clear image. When fitting this de-sign, I tend to use a multifocal add power of no less than +1.50D to +2.00D (“D” design), with the appropriate distance power centrally.
CooperVision also has entered the arena of myopic control with the MiSight® daily disposable myopia control contact lens, which has alternating visual correction and treatment zones.
Another new entry to the market is the NaturalVue Multifocal 1 Day Contact Lenses ® with Neurofocus Optics from Visioneering Technologies, Inc. The lens is designed to provide spectacle-level stereo acuity and vision at near, intermediate and at a distance. A study from University of Waterloo found the lens designs of –10.00D led to nearly complete inhibition of defocus-induced myopia in chickens compared to control lenses (also –10.00D).
Drops are administered at bedtime using Atropine (0.01% to 0.05%) compounded, available in eye drop or ointment form, administered at bedtime, has been found in several studies to reduce the progression of myopia. Applied once a day, atropine treatment is continued as long as myopia progression continues. It is not a cure, but it has shown to control myopia in many patients and in some cases may be used in conjunction with bifocal eyeglasses to enhance the myopia control effect.
Orthokeratology, also known as OrthoK or CRT (corneal re-shaping technology) is a method where rigid gas permeable lenses are applied to the eye while asleep. The gentle pressure exerted on the cornea, or surface of the eye overnight results in the temporary “molding” of the outer layers, providing “lens like” effects for the user. It could be compared to “orthodontia (braces) for the eyes”. The gentle molding of the surface of the cornea corrects the vision but also controls the myopia progression.
The effects last all day, providing vision for users without wearing glasses or contact lenses during their waking hours. The effects are dramatic and free people from issues with glasses or regular contact lenses for sports, swimming and performing the activities they love to perform. Orthokeratology has many peer-reviewed, randomized and some longitudinal studies that show it is an effective method to reduce the progression of myopia and, in many cases, halt it altogether.
Standard gas permeable designs do not provide significant control of axial length and myopic progression. Myopia control with orthokeratology, however, is highly achievable.
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FYI: History of Orthokeratology
Orthokeratology dates back more than 70 years. Eyecare practitioners used a progression of polymethyl methacrylate (PMMA) lenses in a sequentially flatter base curve to compress the central cornea.
As we approached the mid-1990s, manufacturers began using more advanced lathe and computer designs, which enabled them to take the original reverse peripheral curve lenses developed in the 1980s and advanced the study of orthokeratology. This led us to the “modern-day” reverse geometry accelerated corneal reshaping with overnight ortho-k lenses.
There are a variety of orthokeratology lenses for controlling myopia. Each has a unique design but follows similar concepts of method. Ortho-k can reduce the amount of myopic refractive error and affect the progression of myopia as a child ages.
As the doctor will determine in their exam, the question is what other visual function factors can play a role in myopia progression. If the child is close to no power or emmetropic prior to starting school – and if the parents are nearsighted or myopic – there is a very high chance the child will progress into myopia.
Often the use of basic vision therapy exercise may be beneficial and fun for the child. It is often recommend to:
- Reduce reading time into increments or sets of time
- Reduce digital time to 20 minutes with 20 second break and look 20 feet away
- Close your eyes for a few moments prior to resuming nearpoint work
- Consider ergonomic stretching - get up out of the chair.
- Line markers for reading: each line of the paragraph with a index card and read line by line. At the end of the paragraph – stop – close your eyes - think and recite or write about what was just read.
- Tracking games: Pacman, Tetris, Space Invaders, Othello, Match targets, Simon are examples of videos games that are terrific for eye tracking - but remember for short sets of time.
- Base Out Prismatic glasses for individuals with myopia with an esophoria (inward eye posture)
- Anti-fatique (low plus add) progressive lenses to assist in near point work ocular stress
- UVA or Transitions protecting spectacle lenses
- Push – Ups and Jumps with various targets
a. BASIC PENCIL PUSHUP
- Hold a pencil out at arm’s length in front of you. Slowly bring it toward your nose. When you see 2 pencils, push the pencil out slightly until you see 1 again. Focus on the pencil tip for 10 seconds, and then push it back out to arm’s length. Repeat.
- Hold a pencil out at arm’s length in front of you. Bring it toward you. When you can no longer focus on the pencil, push it out slightly until you can focus on it. Hold it there. Alternately, focus on pencil tip, then object in the distance, then back to pencil.
b. Jumps: NEAR & FAR: Brock String or Ruler Jumps
- The concept is to teach the eyes to refocus with more flexibility at distance then intermediate (18-24”) and then nearpoint (14-16”) dependent upon the child’s or adults working distances.
- Brock string is a common vision therapy tool. It consists of a white flexible cord or string, approximately 10 - 15 feet in length, with colored wooden beads that can be moved to various positions along the length of the string.
- The Brock offers instant feedback to the participant if their eyes are working together to focus on an object at various distances. The Brock string is often used invision therapy for patients with vergence disorders such asConvergence Insufficiency, patients withAmblyopia (also calledLazy Eye), and for patients withStrabismus.
- USING RULERS: This can also be done with rulers which afford an accommodative target at distance intermediate and near.
- Stretch your arms to full length – hold one ruler in your hand
- With the other hand – place a second ruler at your mid-arm
- Then simply look at a distance target such as clock on the distant wall – read the numbers –stop
- Look the furtherest ruler and start to read the numbers 1-2-3-4-5 stop
- Go the ruler in the other hand closer to you and continue to read 6-7-8-9-10 stop
- Go back to the first ruler : 11-12-13-14 stop
- Go back to the closer ruler: 1-2-3-4-5 stop
- Back to the first ruler: 6-7-8-9-10 stop and repat multiple times.
Myopia control is a complex management decision based on many factors. The primary factors are the awareness and concern of the parents, while other concerns are the capabilities and understanding of the child. Each approach must be planned from a long term perspective using a building block approach.
We hope that this detailed FAQ summary is helpful for parents and patients in their understanding of Myopia and Myopia Control and the life long implications.
Please feel free to communicate with our offices to discuss.
Kenneth Daniels, OD, FAAO, is an adjunct assistant clinical professor and National Eye Institute clinical investigator attending preceptor in Cornea and Specialty Contact Services at the Pennsylvania College of Optometry, and he is in private practice in Hopewell and Lambertville, NJ.