Contact Lens Design & Materials
Multifocal Designs for Myopia
BY DAVID L. KADING, OD, FAAO
A contact lens that can help reduce myopia progression is a highly sought after item. With billions of people around the world affected by myopia, and it being the number one condition of preventable vision loss, we continue to look.
On a routine basis, I see patients’ parents who desire a method to slow down or halt the progression of their child’s myopia. Many parents are also looking for a solution for themselves. We discuss several ideas and theories, but none have been shown to halt the progression altogether. Others may not be as clinically applicable or are not commercially available. Although the U.S. Food and Drug Administration has not given clearance to any product in this category, researchers continue to look at products that may help slow myopia progression.
An Off-Label Option
Recently, Walline et al (2013) published a study that may help shed light on a clinically relevant off-label option.
The purpose of the study was to compare the progression of axial elongation and myopia on subjects who wore commercially available distance-center soft multifocal contact lenses compared to an age and gender matched group wearing spherical soft contact lenses. Forty children were enrolled. These subjects had myopia ranging from –1.00D to –6.00D, and their ages were between 8 to 11 years old.
The subjects were matched by gender and age to participants with similar eligibility who were enrolled in the Adolescent and Child Health Initiative to Encourage Vision Empowerment (ACHIEVE) Study (Walline et al, 2006) and used single vision soft contact lenses. This group served as the control group.
The study patients wore Proclear Multifocal D (distance-center, see figure) lenses in both eyes for a period of two years. Throughout the study, the subjects returned for visits to have A-scan ultrasound and cycloplegic autorefaction performed.
At the conclusion of the study, the multifocal distance-center lenses had slowed the growth of the eye by approximately 29%, and the refractive error progression had slowed by 50%.
In other studies, the peripheral retina has been shown to be a very important regulator of eye growth in monkeys (Walline et al, 2013; Smith et al, 2009; Smith et al, 2005). Distance-center multifocal lenses present two focal points of light: one on the retina and the other anterior to the retina. This creates a myopic blur that has been shown to slow eye growth in animal studies (Smith et al, 2007; Smith, 1998; Troilo and Wallman, 1991).
Future studies need to be conducted to bring more clarity, but multifocal distance-center contact lenses may assist with slowing the progression of myopia. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #220.
Dr. Kading is in practice in Seattle and is an adjunct faculty member at Pacific University. He is co-owner of Optometric Insights with Dr. Brujic. He has received honoraria for speaking, writing, participating in an advisory capacity, or research from Alcon Laboratories, Allergan, Art Optical, B+L, Contamac, CooperVision, Essilor, Nicox, Paragon, STAPLE Program, SynergEyes, RPS Detectors, Unilens, Valeant, Valley Contax, Vistakon, and The Vision Care Institute.