Talking to a myopic adult about risks for their children

When providing clinical care to adults with myopia, we must consider their best possible vision correction and monitor their ocular health. Both adult-onset myopia and progression of myopia in adulthood can occur. Once refraction is stable, adult myopes require special attention paid to their ocular health, including annual retinal health review if they are high myopes and/or have an axial length of at least 26mm.¹ 

When it comes to childhood myopia management we are aiming to proactively address risk of myopia onset, as well as slow myopia progression. How can we best talk to our myopic adult patients about the risks for their children? Parents may or may not be aware of myopia risks or myopia control options in today's world of eye care. As clinicians, we are comfortable discussing the genetic links of glaucoma and macular degeneration, but do you discuss myopia risk with families in your practice?

Raising the message of family risk during either history taking or advice and management is as easy as asking "Do you have any children? Have you had their eyes checked?" In many circumstances parents may not know myopia management is an option, and may fear that children face the same experience they did with escalating prescription in their own childhood. This is the opportunity to discuss known factors for reducing risk of myopia onset, and the opportunities to slow axial eye growth with myopia progression treatments.

Having one parent whom is myopic and one who is not increases the risk of myopia in children by three times.² If a child is +0.75 or less at age 6-7 this is the most significant risk factor for future myopia - combining this with parental myopia increases risk, but parental myopia is a lesser factor if a child has an age-normal amount of hyperopia.³

Having two parents whom both have myopia increases the risk in children by six times.² Children who have two myopic parents and a low hyperopic refraction, of +0.75 or less in the first grade (age 6-7 years) only have a 23% chance of avoiding myopia onset by their teenage years.³

Children who have a parent with high myopia are more likely to develop myopia and progress to high myopia themselves. Children with highly myopic parents were also found to progress faster, in both spherical error and axial length.⁴

Determining sibling risk as an independent factor is complicated by sharing both parental genes and common visual environmental factors. There is evidence suggesting, though, that if a child has an older sibling who is myopic, there is a high risk they will become myopic as well, whether they have myopic parents or not.⁵

Keep in mind that independent of all of these factors, the strongest predictor for developing myopia by the teenage years is lower than age-normal hyperopia.⁶ If a child has a refraction of +0.75D or less at age 6-7 years, they have around a 50% likelihood of becoming myopic by their teen years if they have no myopic parents. With two myopic parents this increases to a 77% likelihood.³

In having this discussion with a parent, during their eye examination and not that of their child, you may wish to simply overview the key factors in visual environment rather than ask specifically about their child's habits. You can then direct them to further resources such as MyKidsVision.org and explain you will discuss it further during their child's eye examination. The information below is designed to prepare you for common questions parents may ask in response.

When children on average spend less than 90 minutes a day outside, they are at higher risk of myopia.⁷ This is the single most evidence-based intervention for delaying myopia onset,⁸ and is simple advice to give. If parents ask about what children should be doing when spending time outdoors, the World Health Organization recommends at least 60 minutes of mostly aerobic, moderate-to-vigorous intensity physical activity for children aged 5-17. Sun protection is important and doesn't impact the bright-light ocular growth-modulating benefits of outdoor time.⁹

Whilst there isn't yet a clear link between screen time and myopia,¹⁰ suspicion is high and more objective data is needed. There is a clearer link between total time spent on near tasks and closer viewing distances and myopia, though - the simple rule is to try and keep leisure near time to less than two hours per day,⁷ and to take regular breaks. Read Screen Time Guidelines for Children - Resources for Eye Care Practitioners for government screen recommendations and handouts to help discuss this subject with parents.

First things first, ensure that the adult myope has their own eye health requirements covered. Positive framing of health behaviours - for example, explaining the benefits of regular eye exams and use of advanced technology - generally achieve better patient uptake and compliance than negative framing - for example, focusing on the visual impairment and eye disease that a myope may experience in their lifetime.¹¹  This doesn't mean you avoid talking about risk, but rather focus on the actions within the control of your patient.

1. Ensure understanding of myopia risks: that myopia isn't just about vision correction, and even if they've undergone refractive surgery, their ocular health requires ongoing monitoring to ensure healthy eyes and clear vision.
2. Measure axial length: where possible, to gain the clearest picture of their ocular health risk - provide annual retinal health reviews for myopes with axial lengths of at least 26mm.

It is an important balance to take the opportunity of discussing childhood myopia risks with a parent, without instilling too much fear about their own personal ocular health risks. If your adult myopic patient has school-aged children, consider advising the following to them as a parent.

1. Recommend regular eye exams for their children. Explain that even if a child has perfect vision, there can be signs indicative of future myopia to be identified. In addition to lower-than-age-normal hyperopia, measuring axial length can also help to place a child's eye growth relative to their peers. Read more about this in How to use Axial Length Growth Charts.
2. Provide advice on visual environment. Aim for at least 90 minutes of outdoor time per day, and less than 2 hours of leisure near work or screen time per day.

• Adult Myopia Progression, And How To Treat It

• Measuring The Whole Eye in Myopia

• Case Study: Managing The Adult Progressing Myope With Diabetes

• Case Study: Adult-Onset Myopia: Measurement and Management