Soft Contact Lens-based Myopia Management

By Andrew D. Pucker, OD, PhD, FAAO, FSLS
Assistant Professor
The University of Alabama at Birmingham

Are you prescribing myopia management? I ask this question at the start of every myopia management lecture I deliver. Over the past two years, I have gone from having audiences with no hands raised to now having audiences with upwards of 20 perceny of the attendees raising their hands. While a number of clinical trials are still ongoing, evidence continues to mount regarding the effectiveness and safety of soft contact lens (CL)-based myopia management,1 and because of this, I expect the number of eye care providers prescribing myopia management to increase. The following article is intended to provide clinicians with the basics for prescribing soft CL-based myopia management, so clinicians can begin prescribing this potentially beneficial treatment. This article also includes some progressive suggestions that may help atypical patients who may also benefit from myopia management even though they have not been included in myopia management trials.

Mechanism of Action
CL-based myopia management strategies are thought to reduce myopia progression by reducing peripheral hyperopic defocus (increasing peripheral myopic defocus).2-4 This theory is based upon work from Smith et al.5, 6 Those studies questioned if the fovea was essential for regulating ocular growth.5, 6 During this experiment, the researchers used a laser to ablate the fovea of a monkey’s eye while leaving the fellow eye untouched to serve as a negative control.5, 6 Smith et al. then applied myopia induction treatments to each eye (form deprivation/cloudy lenses in one experiment and minus lenses in the second experiment).5, 6 Myopia was still induced in both eyes, which suggested that the fovea was not essential for regulating eye growth.5, 6 Likewise, this experiment suggested that eye growth is regulated by the peripheral retina.5, 6

This theory has been supported by multiple, human clinical trials that have shown that center-distance multifocal CLs (optics reduce peripheral hyperopic defocus while correcting foveal vision) reduce the progression of myopia.2-4, 7, 8 Research from Berntsen and Kramer also provides evidence for why single-vision CLs do not slow eye growth.9 Berntsen and Kramer specifically demonstrated that an uncorrected myope has myopic blur in the foveal region while that same eye has progressively increasing amounts of peripheral retinal hyperopic defocus (growth signal) moving towards the peripheral retina.9 When a single-vision CL is applied to the eye, foveal vision is corrected; however, single-vision CLs actually increase peripheral retinal hyperopic defocus.9 Conversely, when a center-distance soft multifocal CL is applied to the eye, foveal vision is corrected, but peripheral myopic defocus in induced (stop signal).9 Likewise, these data suggest that greater add powers will result in less peripheral hyperopic defocus and less myopic progression control.9 Nevertheless, the amount of add prescribed needs to be balanced in a way that still allows the patient to have functional vision.10

Multifocal Contact Lens Options
One of the most commonly prescribed, commercially available soft, multifocal CL options is the Biofinity lens from CooperVision.11 This is a one-month replacement daily wear silicone hydrogel CL, which is typically prescribed to both eyes with a +2.50D dominant (center-distance design) add power. A +2.00D dominant add power is sometimes used if the patient has difficulty adjusting to the higher add. The NaturalVue multifocal (single add power option) CL is a daily disposable, hydrogel CL option from Visioneering Technologies, Inc. Neither of these CLs is FDA-approved in the United States for myopia control, and patients should be informed about this issue. CooperVision offers the MiSight multifocal (single add power) CL with an indication for controlling myopia progression, though this CL is not currently available in the United States.

Effectiveness
A 2015 review from Smith and Walline found a 48 percent reduction in myopia progression across included studies with soft CL-based myopia management options.1 A more recent retrospective case series with the NaturalVue soft multifocal CL has found a myopia progression reduction of over 90 percent,8 and a randomized study with the MiSight multifocal CL found a myopia progression reduction of 39 percent.7

Patient Selection
A primary requirement for CL-based myopia control options is patient motivation. The patient must be motivated to wear CLs, and if they are not, CLs are an obviously poor choice for myopia management. Another primary consideration should be that the commonly prescribed soft multifocal CL options only come in spherical distance powers. Therefore, patients who have cylinder power more than 1.0D often have trouble achieving adequate vision in these CLs. Aside from these two issues, younger patients and patients with refractive errors closer to emmetropia (e.g., start when the first pair of spectacles is prescribed) are the patients who will likely benefit the most because these patients have the potential to have the most future growth.12

Special Fitting Considerations
The general population has a 14.9 percent prevalence of astigmatism, which frequently prohibits the use of the above CL options.13 Nevertheless, these patients are still often interested in CL-based myopia management. While not currently supported by clinical trials, there are custom multifocal toric CL options that at least in theory should have a similar ability to slow myopia progression as the commonly used spherical multifocal CLs. Likewise, clinical trials have not included patients who develop myopia during their early 20s, though these patients may too benefit from myopia management if the condition is still progressing. If patients in these groups are treated, they should be fully informed about the current state of the literature before treatment begins.

Conclusion
The literature supports CL-based myopia management, and these interventions are well accepted by the optometric community.1 Thus, I highly encourage you to either offer this potentially vision-saving care to your myopic pediatric patients or at least refer to a provider who offers these treatment options.14

References

  1. Smith MJ, Walline JJ. Controlling myopia progression in children and adolescents. Adolesc Health Med Ther 2015;6:133-140.
  2. Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol 2009;93:1181-1185.
  3. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res 2005;30:71-80.
  4. Walline JJ, Greiner KL, McVey ME, Jones-Jordan LA. Multifocal contact lens myopia control. Optom Vis Sci 2013;90:1207-1214.
  5. Smith EL, 3rd, Hung LF, Huang J. Relative peripheral hyperopic defocus alters central refractive development in infant monkeys. Vision Res 2009;49:2386-2392.
  6. Smith EL, 3rd, Ramamirtham R, Qiao-Grider Y, et al. Effects of foveal ablation on emmetropization and form-deprivation myopia. Invest Ophthalmol Vis Sci 2007;48:3914-3922.
  7. Ruiz-Pomeda A, Perez-Sanchez B, Valls I, Prieto-Garrido FL, Gutierrez-Ortega R, Villa-Collar C. MiSight Assessment Study Spain (MASS). A 2-year randomized clinical trial. Graefes Arch Clin Exp Ophthalmol 2018;256:1011-1021.
  8. Cooper J, O’Connor B, Watanabe R, et al. Case Series Analysis of Myopic Progression Control With a Unique Extended Depth of Focus Multifocal Contact Lens. Eye Contact Lens 2018;44:e16-e24.
  9. Berntsen DA, Kramer CE. Peripheral defocus with spherical and multifocal soft contact lenses. Optom Vis Sci 2013;90:1215-1224.
  10. Schulle KL, Berntsen DA, Sinnott LT, et al. Visual Acuity and Over-refraction in Myopic Children Fitted with Soft Multifocal Contact Lenses. Optom Vis Sci 2018;95:292-298.
  11. Walline JJ, Gaume Giannoni A, Sinnott LT, et al. A Randomized Trial of Soft Multifocal Contact Lenses for Myopia Control: Baseline Data and Methods. Optom Vis Sci 2017;94:856-866.
  12. Group C. Myopia stabilization and associated factors among participants in the Correction of Myopia Evaluation Trial (COMET). Invest Ophthalmol Vis Sci 2013;54:7871-7884.
  13. Hashemi H, Fotouhi A, Yekta A, Pakzad R, Ostadimoghaddam H, Khabazkhoob M. Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis. J Curr Ophthalmol 2018;30:3-22.
  14. Ogawa A, Tanaka M. The relationship between refractive errors and retinal detachment–analysis of 1,166 retinal detachment cases. Jpn J Ophthalmol 1988;32:310-315.

 

Print Friendly, PDF & Email

LEAVE A REPLY

Please enter your comment!
Please enter your name here