The Great Myopia Debate

How big a role does genetics play in the development of myopia?

Dr. Cheryl Chapman, president of the American Academy of Orthokeratology and Myopia Control (AAOMC) and the owner of Gretna Vision Clinic in Gretna, Nebraska, is a renowned orthokeratologist. Her dedication to advancing myopia management is evident through the establishment of a comprehensive myopia management clinic within her practice. She emphasizes that genetics plays a major role in the presence of myopia.

by Andrew Sweeney

Is myopia genetic? While lifestyle factors are closely associated with this condition, it is still important to emphasize that genetics plays a significant role in determining myopia susceptibility and severity.

We all know genetics plays a crucial role in many aspects of our physical makeup, from the color of our eyes to whether or not we have earlobes — or when we are hardwired to avoid certain types of foods. If our genes contribute to our 'nature', then it's also fair to say that ‘nurture’ plays a crucial part in determining who we are as people — and some of the most common conditions around are very much caused by nurture.

“It is clear that genetics plays a role in the development of myopia,” Dr. Chapman said. “Heritability studies generally estimate the inheritance of myopia to range somewhere between 60% and 80%. At this time, nearly 200 genetic loci linked to myopia have been identified.”

“We know that a family history of myopia not only increases the risk of a child developing myopia but also increases the risk of them experiencing a fast progression of myopia. A child with one myopic parent has a 1.5-times greater risk of developing myopia. A child with two myopic parents has a three-times greater risk of developing myopia,” she continued.

Dr. Chapman said that it’s important for optometrists to remember that there are several inheritable syndromic conditions that are often associated with myopia and that the pathogenesis of secondary syndromic myopia in these conditions is often different from that of primary myopia.

As such, these cases often respond differently to standard myopia management therapies, which can have a considerable impact on patient outcomes. Examples of such conditions include Marfan's Syndrome and Ehler's Danlos Syndrome, both genetic conditions that affect the body’s connective tissue; and Stickler's Syndrome, a hereditary condition characterized by a unique facial appearance, abnormalities in the eyes, hearing loss, and joint issues

Early intervention is key

“An alternate treatment that may sometimes be more effective in these cases is the use of ophthalmic pharmaceuticals that lower intraocular pressure, such as prostaglandin analogs. Secondary syndrome myopia cases can be very severe and onset at a young age, so it is important for clinicians to be aware of these details and should consider it a red flag if a young child has myopia where the dioptric power reads higher than the patient's age,” Dr. Chapman explained.

“For example, if you have a four-yearold that is a -5.00 D or higher myope, that would warrant communication with the child's pediatrician and should include a recommendation for a genetic workup,” she continued. “Another red flag for clinicians to watch out for would be if the myopic patient exhibits other signs of syndromic conditions that could manifest with variations in physical attributes or developmental milestones,” she said.

“Eye care providers should proactively work with primary care providers like pediatricians to perform genetic testing when appropriate to uncover syndromic conditions associated with myopia. Implementing patient intake forms and questionnaires to determine the genetic risk of myopia based on parental myopia and to screen for signs and symptoms of syndromic conditions is important,” she added.

The good news, however, is that according to Dr. Chapman, there is a constant stream of new science and study outcomes for optometrists to continue understanding the role genetics play in myopia. She recommends seeking membership resources and continuing education from entities like the AAOMC as an actionable and sustainable step. She added that the alignment organizations like hers can limit the amount of time required to research new developments and how to implement them.

Don’t be a skeptic about epigenetics

This is important, as Dr. Chapman is keen to emphasize that practitioner education and consumer awareness campaigns are two of the most important things that can help shift more providers to being highly trained in modern-day myopia treatment.

Practitioner education is important because it improves access to care. Consumer awareness about treatments currently available is key to ensuring that they can have an open discussion with their provider on new options like epigenetics.

“Epigenetics is a fascinating area of study that can shed light on the combined impact that genetics and environment can play on the development of myopia. Put very simply, epigenetics refers to certain genes being turned on or off due to environmental influences. Interestingly, it has been found that epigenetic changes can be heritable,” Dr. Chapman said.

“Even though epigenetic changes don't change the DNA code, the changes that affect what genes are turned on and off can be passed down in families. Attempts to reveal how epigenetic changes impact myopia development are underway and may provide great insight into future myopia treatments,” she said.

“I believe we will see massive developments in our ability to screen for myopic risk factors, as well as our ability to halt the progression of myopia. I anticipate our understanding of the role of genetics in myopia will drive some of these developments. In fact, I would not be surprised to see the advent of buccal swab testing to pinpoint those individuals most at risk,” she concluded.

Contributing Doctor

Dr. Cheryl Chapman , OD, IACMM, FIAOMC, FAAO, Diplomate ABO, is the president of the American Academy of Orthokeratology and Myopia Control (AAOMC) and works in private practice in Gretna, Nebraska. She has instituted a full scope Dry Eye Subspecialty as well as a Myopia Management Subspecialty within her practice. Dr. Chapman is the co-founder of Peeq Pro, a designer of the patent-pending device, the Peeq Waiva, and a co-creator of multiple products and services for Peeq Pro. In addition to working oneon-one with doctors to implement practice protocols, she lectures within the optometric community as well as to local pediatricians and ophthalmologists. Serving as an adjunct assistant professor at the University of the Incarnate Word Rosenberg School of Optometry, Dr. Chapman also enjoys working closely in training fourth-year extern students in current dry eye therapies, myopia management strategies, and practice management. She is a graduate of the University of Houston College of Optometry.