Exploring New Approaches to Myopia Management and Eye Growth Mechanisms

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December 16, 2024

Insights from EssilorLuxottica’s Research at the International Myopia Conference 2024: Part I (click here for Part II)

Compiled by Shilpa Yalamanchili, Senior Global Professional Relations Manager, EssilorLuxottica; abstracts written by the original authors

At the 2024 International Myopia Conference (IMC), EssilorLuxottica presented new research on myopia, exploring how age, lens design, and underlying eye growth mechanisms may impact myopia progression and efficacy. The studies also highlighted advancements in understanding how eye movements relate to myopia progression control and developing predictive models for myopia onset. These findings underscore the importance of personalized strategies and provide valuable insights into the underlying processes driving myopia development. This article (and Part II) summarizes key studies presented by EssilorLuxottica’s R&D team.

1. Influence of Age on Myopia Control Efficacy in Chinese Children Wearing Spectacle Lenses with Aspherical Lenslets

Authors: Ee Woon Lim^1,2; Yingying Huang^2,3; Xue Li^2,3; Yee Ling Wong^1,2; Adeline Yang^1,2; Björn Drobe^1,2; Hao Chen^2,3; Jinhua Bao^2,3

Affiliations: 

1. R&D, EssilorLuxottica, Singapore, Singapore 
2. Wenzhou Medical University–Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, 325027, China 
3. National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China 

Summary:
This study evaluated the effect of age on myopia progression and axial elongation in children wearing spectacle lenses with highly aspherical lenslets (HAL), slightly aspherical lenslets (SAL), and single-vision lenses (SVL). A total of 157 children, aged 8-13 years with spherical equivalent refraction (SER) ranging from -0.75D to -4.75D, completed a two-year, double-masked, randomized trial conducted in Wenzhou, China, with measurements of cycloplegic SER and axial length (AL).

 The results showed that age had no significant impact on the progression of myopia or axial elongation in children wearing HAL lenses. This suggests that HAL spectacle lenses provide consistent myopia progression control, regardless of age within the 8-13-year group. In contrast, both SAL and SVL lenses showed age-related variations, with older children experiencing greater myopia progression and axial elongation. These findings support the potential of HAL spectacle lenses as a reliable, age-independent solution for myopia management in children aged 8-13 years. Importantly, the lack of age-related differences in slowing myopia progression and axial elongation of HAL spectacle lenses could simplify myopia management strategies, offering a consistent approach to effective myopia management across a broad age range. 

2. Impact of lenslets structure of Stellest on the characteristics of fixational eye movements

Authors: RN. Raveendran¹, SM. Doustkouhi¹, SY. Lim¹, EW. Lim¹, B. Drobe¹

Affiliations:

•  R&D, EssilorLuxottica, Singapore, Singapore

Summary:
Fixational eye movements (FEM), which are essential for maintaining stable vision during visual tasks, play a crucial role in both central and peripheral visual processing. This study explored how the lenslets’ structure of Essilor Stellest lenses (HAL) affects FEM, with a particular focus on two key aspects: fixation stability and microsaccadic movements. Nine participants with best-corrected visual acuity (BCVA) of ≤ 0.1 logMAR performed a peripheral orientation discrimination task while wearing either single-vision lenses (SVL) or Essilor Stellest lenses. 

The study found that fixation stability while performing the peripheral discrimination task was similar between the two lens types at all contrast levels. However, the key difference lay in the microsaccadic characteristics: participants wearing Essilor Stellest lenses exhibited smaller (amplitude) and faster (peak velocity) microsaccades compared to when they wore single-vision lenses. The changes in microsaccadic behavior observed when using HAL spectacle lenses could play a role in myopia progression control mechanisms. Further research is needed to better understand how these changes in eye movements relate to myopia progression control.

3. Impact of a myopia control spectacle lens with highly aspherical lenslets on eye tracking and autorefraction.

Authors: SM. Doustkouhi¹, RN. Raveendran¹, EW. Lim¹, SY. Lim¹, A. Gopalakrishnan¹, B. Drobe¹

Affiliations:

1. R&D, EssilorLuxottica, Singapore, Singapore.

Summary:
As myopia progression control spectacle lenses, such as those with highly aspherical lenslets (HAL), become more prevalent, it is important to understand how these lenses affect the outcome measures of common optical measurement devices such as autorefractors and eyetrackers. This study examined how HAL lenses affect the precision of these devices. Refractive error fluctuations were measured under two conditions: with the autorefractor steady relative to the model eye and lens, and with the autorefractor moved swinging laterally within a sub-millimeter range, staying within the allowable limits of the autorefractor. Additionally, gaze data was recorded from a facial image using a Tobii Pro Spectrum eyetracker. Four test arrangements were evaluated: no lens (NL), an infrared-pass filter (IR), single-vision lenses (SVL), and HAL.

Refractive error measurements showed that under the steady condition, all lens arrangements had no impact on precision. However, under the moved condition, HAL lenses significantly increased measurement variability compared to the other arrangements, indicating a reduced precision in the autorefractor readings. Regarding eye gaze, no significant differences were found between HAL, SVL, and IR lenses in terms of fixation stability. However, all lenses, including HAL, caused greater fixation variability compared to NL. These findings suggest that HAL lenses can impact the optical signals processed by autorefractors and eyetrackers, potentially influencing measurements of fixational eye movements and accommodative microfluctuations. Understanding these artifacts is essential for interpreting visual function data in studies involving myopia progression control lenses.

4. Myopia Incidence, Risk Factors, and Predictive Model for Myopia Onset Among Indian Children

Authors: Aparna Gopalakrishnan¹, Yee Ling Wong¹, Hua Ren Chua¹, Björn Drobe¹, Amirta Murali², Anuradha Narayanan²

Affiliations:

1. R&D Singapore, EssilorLuxottica, Singapore, Singapore
2. Elite School of Optometry, Medical Research Foundation, Chennai, India

Summary:
This study, part of the Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) study, aimed to examine the incidence of myopia and develop a predictive model for myopia onset among children aged 6 to 12 years in South India. A total of 14,342 children were initially screened. Children from grades 1, 4, and 6 (aged 6, 9, and 12 years at baseline) underwent comprehensive examination, including refraction, binocular vision assessment, and ocular biometry at baseline and all follow-up visits. A total of 2,332 children in the three grades were assessed over a three-year follow-up period. The study found that 8.8% of children developed myopia during the study period, with significant risk factors identified for myopia onset, including baseline spherical equivalent refraction, axial length, and corneal curvature, after adjusting for age and gender.

A predictive model developed using these factors demonstrated strong performance with an area under the curve of 0.8566 and a predictive accuracy of 92%. With further validation, this model could serve as a practical clinical tool to identify children at risk for myopia development, enabling early intervention and prevention strategies. By identifying children at risk early, clinicians could implement targeted interventions to manage myopia progression and potentially reduce the future burden of myopia in India.

5. Variations in physiological and myopic eye growth among children from different populations

Authors: Yee Ling Wong^1,2, Yimin Yuan^2,3, Yingying Ye^2,3, Björn Drobe^1,2, Hao Chen^2,3, Jinhua Bao^2,3

Affiliations:

1. R&D, EssilorLuxottica, Singapore, Singapore
2. Wenzhou Medical University–Essilor International Research Center (WEIRC), Wenzhou Medical University, Wenzhou, 325027, China
3. National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China

Summary:
This study, part of the Wenzhou Medical University-Essilor Progression and Onset of Myopia (WEPrOM) cohort, compared physiological and myopic eye growth in children aged 7-9 years in Wenzhou, China, to other global populations, including those from Singapore and the U.S. The analysis included 700 non-myopic and 297 myopic children followed for 4.5 years using logistic function models to track changes in eye growth. The results were compared to similar studies conducted in Singapore, the U.S., and other regions in China.

The study found that physiological eye growth in Wenzhou children was comparable to other Chinese cohorts but greater than that seen in the Singapore Cohort Study of the Risk Factors for Myopia (SCORM) and the Orinda Longitudinal Study of Myopia (OLSM). Myopic eye growth in Wenzhou children was also similar to other Chinese studies but greater than in Singapore and Orinda populations. These findings reveal significant variations in eye growth patterns across different ethnic and geographical populations. They suggest that myopia progression control outcomes, particularly those related to axial elongation, should be interpreted in the context of specific population physiological eye growth rates. The study emphasizes the need to consider both family history and environmental factors when assessing myopia progression and designing effective interventions.

6. Nonlinear spatial integration allows the retina to detect the sign of defocus in natural scenes

Authors: Sarah Goethals¹, Awen Louboutin², Samy Hamlaoui³, Tom Quetu², Matìas Goldin², Samuele Virgili², Konogan Baranton¹, Olivier Marre²

Affiliations:

1. Group Lens Innovation, R&D Life and Light Science, EssilorLuxottica, Paris
2. Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris
3. Group Lens Innovation, Digital Innovations, EssilorLuxottica, Paris

Summary:
This study explores how the retina detects the sign of defocus, with potential implications for improving myopia progression control lenses. Using a detailed optical model of the mouse eye, the researchers simulated defocused retinal images and projected them on ex vivo mouse retinas. By recording the electrical activity of retinal ganglion cells (RGCs) in response to the defocused images, they discovered that certain RGCs consistently responded to positive (myopic) defocus, with decreased activity. This response was linked to local spatial contrast (LSC), which changes based on the degree of defocus due to the spherical aberrations in the eye’s optics. The study found that a decrease in LSC reliably indicated myopic defocus in both mice and humans, though the reliability of this cue was reduced in near-vision conditions. These findings suggest that the retina uses changes in local spatial contrast to detect the sign of defocus, which may play a key role in regulating eye growth.

These results, which were recently published on Biorxiv (Goethals et al., Biorxiv 2024), provide an explanatory framework for understanding how defocus affects retinal processing. This could inform the development of more effective myopia progression control strategies, offering new insights into delaying myopia onset. Notably, the fact that the LSC decreases with a more myopic defocus is consistent with the recent observation that some efficient myopia progression control lenses decrease the contrast on the retina. The study also provides an explanatory basis for why near-vision tasks increase the susceptibility to myopia. Ultimately, these insights could inform the development of more effective myopia progression control strategies, improving both the design and efficacy of lenses aimed at slowing myopia progression.

Conclusion
The research presented highlights significant advancements in understanding the factors that influence the efficacy of myopia interventions, including age, lens design, ocular biometrics, and ethnicity. These studies underscore the importance of adopting personalized approaches to myopia management — approaches that incorporate customized lens technologies and predictive models for managing myopia onset. As our understanding of retinal mechanisms continues to evolve, ongoing research will further refine these interventions, enhancing their effectiveness and global applicability. The future of delaying myopia onset and management will rely on these insights, driving the development of more effective, individualized strategies for controlling myopia progression.

 

Click here for Part II

 

Disclaimer: Essilor Stellest lenses are currently not available in all countries.