Time for a Myopia Prevention Protocol

There has been essentially zero discussion in the literature about how a doctor might put all the research on myopia development into use in clinical practice. In fact, there has been very little discussion that anything should be done at all to change the standard of care which is still to correct myopes with the least minus for maximum acuity, or some small variation of that strategy.

Historically, there have nearly always been the outliers that espouse more significant interventions, most often some calculated amount of additional plus power for near, either as an aid for efficiency, comfort, clarity, or prevention of progression. Other methods are tried at times, such as RGP wear, undercorrection, removal of glasses for reading, etc.

It's time to put the research to work and develop an actual protocol based on clinical trials reported in refereed journals. This is only one protocol. I hope it begins to generate a significant discussion within the profession as to what a "correct" protocol might be.

Lenses and atropine

Lens interventions are based on the proven principle that creation of a peripheral myopia creates a stop/slow signal for further axial growth and thus myopic progression. The principle has been proven more in animal models but human studies are starting to show the effect. Some devices create peripheral myopia better than others.

The protocol does not incorporate the use of atropine, the one treatment modality that has been proven so far the most effective at stopping myopia progression. That may seem like an odd omission and I think one that may change. The most recent report by Audrey Chia (2011) found under the Research - Medications/molecular menu showed that very low dosages of atropine were very effective with essentially no side effects.

There are serious advocates. Paul E. Romano, in Optometry and Vision Science, in a letter: Much Can Be Done for Your Child's Myopia. Also, Jeffrey Cooper, O.D., Clinical Professor of Optometry at SUNY State College of Optometry advocates for the use of atropine in a Letter to the Editor in Review of Optometry. Thirty one atropine references are cited: Use Atropine for Myopia

Perhaps the most significant thing that the atropine findings have done is spur further research into more specific muscarinic receptor antagonists with the goal of finding one with few side effects. There could even be a pathway that avoids muscarinic receptors. Maybe someday we will pass out MyoPills to those determined to be at risk. For now, if atropine is elected to be part of your protocol, do not fail to give adequate informed consent.

I have not put the rationale for specific recommendations into the protocol itself. The best method to find the rationale is to find the topic under the Treatments menu item or in the summaries of the research articles. Sometimes I just used my own clinical judgment.

You must treat young children if you are serious

You must start to treat children of a younger age. The ability to control the changes is best when the level of myopia is low. Our eventual goal should be to determine when to intervene before myopia manifests with blurred distance vision.

 

Myopia Protocol

(Commentary: I have recently (Fall 2011) been assigned the chairmanship of a committee of the Orthokeratology Academy of America tasked with creating a myopia prevention and control protocol. I have been given free rein to consider every modality, not just orthokeratology. I am assembling a world class group of researchers and clinicians to create a quality document that should guide every doctor in how to treat myopia and I look forward to replacing the rough protocol below that I created one afternoon. Richard L. Anderson, O.D.)

  • Goal is slowing or stopping further progression into myopia
  • Non-cycloplegic near retinoscopy at age 1 year correlates with eventual refractive error
  • Yearly cycloplegic exams starting at age 4 specific to myopia progression
    • Ocular health, cycloplegic refraction, near phoria, lag of accommodation
    • Expected mean spherical equivalent +.50 D. SD= approximately .6 D. (Gwiazda 1993)
    • A-scan if available
    • Counseling about need for 2-3 hours of outdoor time daily.
    • Counseling about need for proper nutrition; reduction of carbohydrates/grains/sugar may be beneficial..
    • Discussion of risk factors due to any parental myopia
  • If patient reaches +.50 to -.25 AND is near esophoric or accommodative lag >=.50 Diopters for a 33 cm target AND has two myopic parents
    • controversial as to whether to begin treatment.
    • counseling about need for 2-3 hours of outdoor time daily.
    • counseling for why lenses are needed when vision is clear
    • devices for creating more peripheral myopia are desired:
      • Bifocals or PALs (not reading glasses)
        • highest add tolerated, +2.00 to +3.00
      • RRG (Radial Refractive Gradient) spectacles when available instead
      • Rx is for full time wear
      • decrease exam interval to every six months until stable for two years
  • If the juvenile patient has moved into myopia (-.50 or worse) WITH cycloplegia
    • Myopia has already been progressing for 1-2 years
    • Review parental risk factors; modify outdoor time, diet
    • The younger the patient, the further myopia is expected to progress
    • The older the patient, the faster the myopia is expected to progress
    • Treatment is most effective for lower levels of myopia, smaller lags of accommodation and more exophoric at near.
    • Most aggressive creation of peripheral myopia possible, in order:
      • Orthokeratology
      • Bifocal contact lenses (center far; CIBA Vision and CooperVision are in Asia)
      • RRG spectacles when available (currently in Asia)
      • Bifocal or PALs spectacles (not reading glasses)
      • Single vision lenses as last resort; remove for near tasks?
  • Adult onset myopia
    • Not as well studied
    • Creation of peripheral myopia is still assumed to be desirable
    • Same prescription devices as for juvenile onset myopia
  • Degenerative myopia of steadily increasing power with pathological changes such as glaucoma, choroidal atrophy, breaks in Bruch's membrane, subretinal neovascular membranes, subretinal neovascularization, retinal breaks and detachments are most likely due to additional mechanisms not well understood yet. No studies have been done to see if control of peripheral hyperopia prevents progression into degenerative myopia but the assumption is that it may help. Treatment of these more severe, sight threatening conditions is beyond the scope of this protocol and needs to be pursued considering the latest available treatment options.