CARE Value: The Key Metric for Myopia ControlDiscover care value

Myopia, an eye problem that affects millions of people worldwide, has been a growing concern for the eye health community. The need to control its progression and minimize the risks associated with serious eye conditions in adulthood has led to a more rigorous focus on research and treatment. In this context, an essential concept has emerged that is changing the way we measure treatment effectiveness: CARE, or “Cumulative Absolute Reduction in Axial Elongation.”

Understanding CARE and its Importance

The progression of myopia in childhood can have serious consequences for eye health in adulthood. However, demonstrating this cause-and-effect relationship through long-term research has been a challenge. Often, studies focus on statistical significance, but this does not always reflect the true value of a treatment. Insufficient sample size can lead to accepting that there are no significant differences or benefits in the treatment being studied (null hypothesis). This is where the CARE approach comes into play.

Breaking Down the Meaning of CARE Value

To understand what the concept of CARE Value means, let’s break down its meaning:

• ‘C’ for “Cumulative”: CARE Value is “cumulative” because it recognizes that treatment effectiveness is not constant over time. This metric acknowledges that treatments may show a significant reduction in axial elongation in the early months, but this decreases over time. Using an accumulated value during the study period provides a more accurate representation of treatment effectiveness over time.
• ‘A’ for “Absolute”: CARE Value is “absolute” in the sense that it measures the effect of treatment in terms of a constant value rather than a relative value. This is crucial as CARE Value offers a more independent and consistent representation of treatment effectiveness compared to percentages.
• ‘RE’ for “Reduction in Axial Elongation”: Axial elongation of the eye has been established as the preferred metric for tracking myopia progression. This is due to its greater accuracy compared to measuring refractive error. Additionally, axial elongation of the eye has been directly linked to the risk of eye conditions associated with myopia and vision loss in adulthood, providing a solid basis for its use as the primary measure.

The Power of CARE

The CARE approach offers a more precise and consistent metric for evaluating the effectiveness of different myopia control treatments. The novelty of CARE lies in its ability to represent the benefits a child undergoing a specific treatment could experience, regardless of their age, progression rate, initial refractive error, and ethnicity. This establishes a common standard that allows for the comparison of different interventions and a more robust approach to measuring real-world effectiveness.

Effectiveness Over Time

It is crucial to note that treatment effectiveness is not constant over time. On average, approximately 40% of effectiveness occurs in the first year. This decrease in effectiveness over time has driven the need to express CARE in reference to the time of application. This helps provide an accurate representation of effectiveness throughout myopia progression.

Balancing Effectiveness and Safety

The choice of a myopia control treatment should be based on a balanced consideration of effectiveness and safety. Reducing the final degree of myopia is crucial in decreasing the risk of myopia-related eye diseases in the future. However, it is also essential to consider patient preferences, side effects, and the possibility of rebound or accelerated myopia progression after treatment discontinuation.

Conclusion

The CARE approach represents a significant advancement in myopia control, providing a standardized measure for treatment effectiveness. Its ability to evaluate this effectiveness in a real-world context, regardless of factors such as age or progression rate, offers a more precise and balanced insight. Additionally, CARE highlights the importance of considering the rebound phenomenon when evaluating long-term treatments, providing valuable guidance for the care of young patients.

With the promise of a clearer future and the importance of choosing the right metric, CARE becomes the primary metric for guiding myopia treatment, emphasizing the need to consider the CARE concept on the path to long-term eye health.

References:

1. Brennan N. Why ‘CARE’ for myopia?. Review of Myopia Management. 2020. Available at: https://reviewofmm.com/why-care-for-myopia/
2. Brennan NA, Toubouti YM, Cheng X, Bullimore MA. Efficacy in myopia control. Prog Retin Eye Res. 2021;83(100923):100923. Available at: https://pubmed.ncbi.nlm.nih.gov/33253901/
3. Faao MBO, David L. Kading OD. IS THIS THE NEW NORM? IS AXIAL LENGTH THE NEW NORM FOR MYOPIA MANAGEMENT? Contact Lens Spectrum. 2022;37:49. Available at: https://www.clspectrum.com/issues/2022/march-2022/is-this-the-new-norm