Prevalence of myopia and high myopia is increasing around the world, and in some parts of the world, it has already reached epidemic proportions.¹ Thirty percent of the world’s population is currently myopic, and by the year 2050, fifty percent will be myopic, and ten percent will be highly myopic.² As a consequence of the increase in myopia and high myopia, there will be an increase in permanent sight-threatening ocular complications such as myopic macular degeneration (MMD), already a leading cause of vision impairment blindness in parts of Europe and Asia.³ Clinicians will need to meet the challenge of an increasingly comprehensive eye care service that detects/diagnoses, corrects and slows myopia, and manages the complications. The costs from the lost productivity of uncorrected myopia as well as permanent vision loss from MMD alone totaled $250 billion in the year 2015,⁴ and it is set to rise in the future. Currently, we have treatments (off-label and approved) to slow myopia progression, but we also need to consider prevention. Based on known risk factors for myopia and a proposed definition for pre-myopia by the International Myopia Institute,⁵ we have a good basis to start evidence-based preventative eye care.

Pre-myopia Defined

The International Myopia Institute⁵ defines pre-myopia as “a refractive state of an eye of ≤ +0.75 D and > -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 preventative interventions.”

Following a comprehensive eye examination where you have taken a thorough history, conducted cycloplegic refraction, and ruled out any other ocular condition, and you find your patient has less hyperopia than expected for their age, with any of the risk factors below, then you can consider them to be pre-myopic.

Ethnicity – we see a higher prevalence of myopia in certain ethnic groups. East and Southeast Asians have a higher prevalence of myopia compared with Europeans, Africans, and Indians.¹

Parental myopia – one myopic parent increases the risk three times, and two myopic parents increase the risk six times.⁶

Reduced time outdoors and increased near work – clinical trials have reported that increasing additional time outdoors to at least 120 minutes per day is protective against new cases of myopia^{7, 8, 15} while intense near work is associated with increased risk of myopia.^9 10

Urban environment – those living in dense cities tend to have a higher risk than in rural or suburban settings,¹¹ as urban environments are linked to less time spent outdoors and more near work activity.

Managing Pre-Myopia

Currently, there is no strong evidence to start optical and pharmacologic treatments in a pre-myope. Studies such as the currently underway ATOM3 trialling low-dose atropine in pre-myopia will guide us in the management of pre-myopes in the near future. For now, we should be advising increased time outdoors of at least 80 minutes daily (with sun protection) and reduced near work to less than 2.5 hours per day.¹² Regular yearly review as a minimum would be recommended for a child that is significantly at risk of developing myopia. This advice should form part of the comprehensive management of a child with myopia too.

Future Objective Measures

Tools such as apps and smart devices worn on frames or as a watch have been trialled to quantify near work hours, posture, and time outdoors. (IMI Environmental risk factors, to be published in IOVS 2021) These could eventually be used to support the management of our patients. Axial length growth charts have been published for European^{13, 16} and Chinese¹⁴ children, and axial length normative data is already being used in biometers such as the Haag-Streit Lenstar Myopia and Oculus Myopia Master.

Much discussion has been directed about using axial length measurement as a critical measurement for myopia management. It is objective, fast, accurate, and easily performed with many of the automated devices available on the market today. When there is more understanding about the precise relationship between axial length and refractive error, it may become the gold standard for clinical management – it is currently a key outcome measure in clinical trials.

Myopia management is an exciting area with new research and technology advancements that will allow us to detect the pre-myope earlier and more accurately manage pre-myopia.  Today, we can detect pre-myopia, potentially prevent myopia, and address myopia’s serious public health challenge.