Myopia control and no rebound with Highly Aspherical Lenslet spectacles

Paper title: Progression of myopia with novel myopia control spectacle lenses

Authors: Rebecca Weng (1), Huy Dinh Minh Tran (1,2), Daniel P Spiegel (3), Bjorn Drobe (3), Thomas John Naduvilath (1), Padmaja Sankaridurg (1,4)

1. Brien Holden Vision Institute, Sydney, New South Wales, Australia
2. Haiyen Eye Care, Ho Chi Minh City, Viet Nam
3. R&D Vision Sciences AMERA, Essilor International SAS, Singapore, Singapore, Singapore
4. University of New South Wales, Sydney, New South Wales, Australia

Date: June 2022

Reference: Weng R, Tran HDM, Spiegel DP, Drobe B, Naduvilath TJ, Sankaridurg P. Progression of myopia with novel myopia control spectacle lenses. Invest. Ophthalmol. Vis. Sci. 2022;63(7):252 - A0106.  [Link to abstract]

This abstract evaluated the progression of myopia in children wearing novel spectacle lenses with highly aspheric lenslets (HAL) in comparison to those wearing single vision spectacles (SV). This randomized, double-masked, cross-over trial involved 119 myopic Vietnamese children aged 7-13 years. 

After 6 months of either HAL or SV wear (Stage 1), children were crossed-over to wear the other lens types for another 6 months (Stage 2). At the end of Stage 2, all children wore HAL for another 6 months. The two groups wore the lenses in the following order:

Group 1: HAL -->SV --> HAL
Group 2: SV --> HAL --> HAL

The results are detailed below:

• During Stages 1 and 2, myopia progressed significantly slower with highly aspheric lenses (0.07mm growth) than with single vision lenses (0.14 to 0.16mm growth).
• Group 1's myopia progression during Stage 2 was not different to single vision progression during Stage 1 of Group 2. Importantly, this indicates no rebound of myopia with cessation of HAL treatment.
• In Group 2, Stage 3 spherical equivalent progression with HAL was greater compared to Stage 2 when wearing HAL, but axial elongation rates were similar (0.07 to 0.08mm over six months). This correlates with other reports of myopia control efficacy, in which the greatest effect is seen in the initial stage of treatment, although focus on the axial length results is more pertinent.
• Children reported long hours of wearing time, of greater than 13 hours per day, and no subjective issues with lens wear were reported by the children.

HAL spectacles were shown to slow myopia progression in this study, with the effect measurable when children commenced or recommenced HAL wear compared to single vision spectacles. Reassuringly, there was no evidence of rebound when children were switched from HAL spectacle lenses to single vision spectacles. 

This novel cross-over design adds to the data of the two year longitudinal study, which you can read about here. Long-term visual performance was not reported in this study, but one short-term study has investigated acuity and contrast sensitivity, and the one-year data reported better than 20/20 equivalent mean acuity and adaptation of all groups to their spectacle lenses within 3 days.

Title: Progression of myopia with novel myopia control spectacle lenses

Authors: Rebecca Weng, Huy Dinh Minh Tran, Daniel P Spiegel, Bjorn Drobe, Thomas John Naduvilath, Padmaja Sankaridurg

Purpose: To evaluate the progression of myopia in children wearing novel spectacles with highly aspherical lenslets (HAL) versus conventional single-vision spectacles (SV) in a randomized, double-masked, and cross-over trial.

Methods: 119 Vietnamese children, aged 7 to 13 years with baseline (BL) refractive error ranging from -0.75 to -4.75D, cylinder ≤ 1.50D were assigned to 2 groups to wear either HAL or SV, and after 6 months (Stage 1) crossed over to wear the other lens type for another 6 months (Stage 2). At the end of stage 2, all children (n=105) wore HAL for a further 6 months. Based on the order in which they wore the lenses at each stage, Group I was designated HSH (HAL - SV - HAL) and Group 2 SHH (SV-HAL-HAL). Cycloplegic autorefraction was performed at BL and then every 6 months and axial length (AL) measurements were collected at BL and 3 monthly thereafter. Myopia progression (change in spherical equivalent refractive error (SE) and AL) was compared between groups. A linear mixed model with subject random intercept (adjusted for confounders -age, gender, parental myopia) was used for analysis. Post hoc multiple comparisons were Bonferroni corrected. The level of significance was set at 5%.

Results: During stages 1 and 2, myopia progressed slower with HAL than SV (significant for AL for both stages and SE for Stage 2). In the HSH group, myopia progression with SV during Stage 2 was not different to SV progression observed at Stage 1 SHH group (p=0.208 and 0.092 for SE and AL respectively) and indicates no rebound of myopia. In the SHH group, Stage 3 change in SE with HAL was greater compared to stage 2 (p<0.001) but not for AL. Children reported long hours of wearing (>13 hrs/day) and there were no subjective issues with lens wear.

Conclusion:  HAL spectacles slow myopia. This is evidenced by a) inter-group comparisons at Stages 1 and 2, and b) intragroup comparison when children switched between HAL and SV between stages. Children were compliant with lens wear and in this short-term, cross-over study there was no rebound when children were switched from HAL to SV. The reduced SE change with prolonged wear of HAL (Stage 2 to Stage 3 in the SHH group) needs further exploration.

[Link to abstract]