Members of the International Myopia Institute developed and proposed standards for definitions and thresholds to facilitate research into myopia prevention that leads to evidence-based medicine.
They recommended that myopia terminology be limited to the following categories: myopia, secondary myopia, axial myopia and refractive myopia and, “as a quantitative trait,” that myopia be classified as all myopia, low myopia and high myopia.
High myopia was defined as a spherical equivalent refractive error of -6.00 D or less, and pathologic myopia was defined as the adverse, structural complications of myopia.
The group also defined “pre-myopia” as “a refractive state no more than +0.75 D and greater than -0.50 D “in children where a combination of baseline refraction, age and other quantifiable risk factors provide a sufficient likelihood of the future development of myopia to merit preventive interventions.”
Lead author of this report, Ian Flitcroft, MA, DPhil, FRCOphth, said the concept of pre-myopia will be new to many.
“This is a condition where children who are still emmetropic have features that indicate they have a high risk of developing myopia,” he told Primary Care Optometry News.
“Myopia develops fastest in young children and in the first years after onset,” he continued. “This means that early intervention will have the greatest impact on reducing the final
amount of myopia. I believe pre-myopia will be a very useful clinical term to identify young children at risk to guide preventive strategies and to ensure that any interventions can be implemented at as young an age as possible.”
Co-author Monica Jong, PhD, told PCON: “Previously myopia and high myopia have been defined many different ways, which has caused confusion amongst researchers and practitioners. The agreed-upon definitions in this white paper means that future research studies will allow better comparison, and practitioners and policy makers can also approach this ocular condition more systematically in their management.”
Flitcroft noted the importance of standardization for research, policy and medical practice.
“Improving our understanding and management of the complications of high myopia is also a critical area. An agreed set of definitions around the complications of this largely untreatable, yet sight-threatening condition, is an essential first step in developing interventions.” – Nancy Hemphill, ELS, FAAO
Disclosures: Flitcroft and Jong report no relevant financial disclosures. Please see the full study for all authors’ financial disclosures.