A 1-year performance report of three spectacle lens designs

Paper title: Spectacle Lenses Designed to Reduce Progression of Myopia: 12-Month Results

Authors: Padmaja Sankaridurg;^1,2,3 Leslie Donovan;^1,2 Saulius Varnas;⁴ Arthur Ho;^1,2.3 Xiang Chen;^3,5 Aldo Martinez;^1,2 Scott Fisher;⁴ Zhi Lin;⁵ Earl L. Smith;⁶ Jian Ge;^3,5 Brien Holden^1,2,3

1. Institute for Eye Research, Sydney, New South Wales, Australia
2. Vision Co-operative Research Centre, Sydney, New South Wales, Australia
3. School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
4. Carl Zeiss Vision, Adelaide, South Australia, Australia
5. International Clinical Trials Centre, Zhongshan Ophthalmic Centre, SunYat Sen University, Guangzhou, People’s Republic of China 
6. College of Optometry, University of Houston, Houston, Texas

Date: Sep 2010

Reference: Sankaridurg P, Donovan L, Varnas S, Ho A, Chen X, Martinez A, Fisher S, Lin Z, Smith EL 3rd, Ge J, Holden B. Spectacle lenses designed to reduce progression of myopia: 12-month results. Optom Vis Sci. 2010 Sep;87(9):631-41.

[Link to open access paper]

Three novel spectacle lens designs developed by Carl Zeiss with the intention of altering the peripheral image shells were fit to myopic Chinese schoolchildren.  The lenses gave clear central optic zones but induced differing amounts of relative positive power in the periphery away from the visual axis.

The children wore the spectacles for the entire year-long clinical study. The results showed that there was no significant difference found for myopic progression or axial length between the performance of the novel lenses and the control lens.

However, when children under the age of 12 with myopic parents were considered separately, they were found to have faster progression rates than the older children and 0.29D less progression was found with lens type III compared to the control lens. Further study is needed to confirm the findings and explore why this should be the case.

The differences in spectacle lens designs for myopia control have been compared on Myopia Profile [here] for further reading. 

A child’s age and their family history of myopia may be important factors for assessing which children may benefit most from wearing lens type III from this study

• The younger children in this study (aged under 12yrs) were found to experience myopia progression faster than the older children (over 12yrs)
• Children aged between 6-12yrs with myopic parents experienced -0.68D progression compared to the mean control lens progression of -0.97D with the control lens

Although the underlying reason for this has not yet been established, younger children with myopic parents appear to benefit more from using the type III novel lens compared to single vision lenses.

This study was originally intended to be conducted over a 2-year period. It was concluded a year early when it was found that older children in the cohort had significantly slower myopia progression than younger children:

• The authors have suggested that longer term efficacy could be assessed for children who are younger and still displaying progression.
• The children who participated in this study had myopia between -0.75D and -3.50D. Further research could reveal if progression of higher myopia could be slowed with these spectacle lens options.
• The study featured Chinese children who have been shown to have different myopic prevalence and progression rates. As such, future research could examine the effects of these novel lens types for children from differing ethnicities with different progression rates.
• Peripheral refraction values were measured at baseline in order to compare to those induced by the novel lenses or the control lens. There were no differences found between the degree of hyperopic defocus provided by each lens type, other than a smaller temporal field for younger children wearing lens types II and III
• The authors did report difficulties in measuring visual field angles through the spectacle lenses and peripheral refraction values were only measurable up to 40°

The differences in spectacle lens designs for myopia control have been compared on Myopia Profile [here] for further reading. 

Title: Spectacle Lenses Designed to Reduce Progression of Myopia: 12-Month Results

Authors: Padmaja Sankaridurg, Leslie Donovan, Saulius Varnas, Arthur Ho, Xiang Chen, Aldo Martinez, Scott Fisher, Zhi Lin, Earl L. Smith, III, Jian Ge, Brien Holden

Purpose: To report the results of 12-month wear of three novel spectacle lens designs intended to reduce peripheral hyperopic defocus and one standard design control lens and their effect on the progression of myopia in Chinese children aged 6 to 16 years.

Methods: Chinese children (n = 210) with myopia (−0.75 D to −3.50 D sphere, cylinder ≤−1.50 D) were randomized to one of four groups wearing either one of three novel spectacle lens designs (types I, II, or III) or conventional, single-vision spectacle lenses. Data were collected at 6 and 12 months. Primary and secondary outcome measures were the changes in central cycloplegic auto-refraction and eye axial length, respectively. Peripheral refraction along the horizontal meridian (nasal and temporal) was taken at baseline with and without spectacle lenses. Multivariate linear regression was used to adjust analyses for important covariates.

Results: Progression in eyes wearing control spectacle lenses at 6 and 12 months was −0.55 D ± 0.35 D and −0.78 ± 0.50 D, respectively. For the entire group, no statistically significant differences were observed in the rates of progression with the novel designs in comparison to control spectacle lenses. However, in younger children (6 to 12 years) with parental history of myopia (n = 100), there was significantly less progression (−0.68 D ± 0.47 D vs. −0.97 D ± 0.48 D) with lens type III compared with control spectacles (mean difference, 0.29 D, std error, 0.11, p = 0.038).

Conclusions: There were no statistically significant differences in the rate of progression of myopia between the control and novel lens wearing eyes for the age group 6 to 16 years. The finding of reduced progression of myopia with type III lens design in younger children with parental myopia needs to be validated in a more targeted study.

[Link to open access paper]