Younger age was the strongest factor associated with faster myopia progression, but females and children with higher myopia were also at higher risk of faster progression. Photo: Getty Images.

Myopia prevalence has almost doubled over a 30-year period in teenagers and adults in the United States and is now in more than 50% of young adults in parts of Europe. Control group data from randomized controlled trials have been proposed as a basis for predicting myopic progression, but clinical trial cohorts may not reflect real-world myopia progression. A new retrospective analysis of EMR data investigated the natural history of myopic progression in children from optometric practices in Ireland and found that younger age was the strongest factor associated with faster myopia progression, but girls and any children with higher myopia were at higher risk.

The analysis was of myopes aged seven to 17 with data from multiple visits who were not prescribed myopia control treatment. Sex- and age-specific population categories for annual myopic progression were derived. These were compared to progression rates derived from control group data obtained from 17 randomized clinical trials for myopia. Survival analysis was performed to determine the intervals at which a significant level of myopic progression was predicted to occur.

Myopia progression was highest in children aged seven years and progressively slowed with increasing age; however, 35% of those aged 16 were still progressing 0.25D or more per year. Female sex, a more myopic SER at baseline and younger age were all found to be predictive of faster myopic progression.

“It should be noted that two of the comparison randomized clinical trials required a minimum level of myopia progression, which may partially explain the high level of control group myopia progression in these studies; however, a re-analysis excluding these investigations made minimal difference to the overall control group median myopic progression (-0.50D vs. -0.49D per year) and was still much worse than that observed in the EMR data (-0.35D/year),” the researchers noted in their paper on the study.

This study confirmed that myopic progression extends beyond 16 years of age, with 35% and 13% of 16 to 17 years old showing annualized progression of at least -0.25D and -0.50D, respectively. Continued progression in this older age group has also been observed in other investigations, such as the COMET study and the DREAM study.

The COMET study, for example, reported a high prevalence of progressive myopia among older individuals, with 23% of 18-year-olds exhibiting myopia progression of at least -0.50D/year. The DREAM study observed that among participants 16 and 18 years of age, those with a notable history of myopia progression advanced at least -0.25D/year.

“The collective findings from both the current and previous studies suggest that clinicians need to consider the implications of longer-term myopia progression in their clinical decision-making process regarding the need for and potential benefit of myopia management in individual patients,” the authors wrote, adding that “a substantial number of participants of all ages with myopia did not progress at all. This non-progressor proportion increased from approximately 15% among seven to eight years old to 39% among 15 to 17 years old.”

The survival analysis indicates that a conservative approach with relatively short recall periods is required to detect all significant myopia progression in a timely manner. “The proportion of children that experienced myopic progression increased as a function of the recall interval, but even at a 12-month interval, 25% to 62% of children aged 12 and younger had myopia progression of <00.50D/year, compared to 14% of adolescents aged 13 years and older,” the article explained. “Past myopic progression alone has not been found to correlate well with predicted future progression, so clinicians should consider the individual child and their specific risk factors in totality when determining the appropriate recall period.”

The ability to estimate reliably the expected refractive error progression of a presenting myopic or pre-myopic patient is valuable for clinical practitioners, the authors suggested. “The development of predictive analytic tools such as centile charts of refraction and axial eye growth could guide clinical decision-making, provide reference data to assess myopia control treatment efficacy and facilitate enhanced communication with patients.”

These findings will enable clinicians to better predict both refractive outcomes without treatment and monitor treatment efficacy, particularly in the absence of axial length data, the authors noted, but also added that “predictive tools that rely on clinical trial data appear biased towards faster myopia progression, are inconsistent with real-world observations and should be used with caution when predicting future progression or assessing treatment efficacy.”