Myopia control with diffusion optics technology: preliminary results from the CYPRESS study

Paper title:  Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS)

Authors: Joe Rappon (1), Carol Chung (2), Graeme Young (3), Christopher Hunt (3), Jay Neitz (4), Maureen Neitz (4), Thomas Chalberg (1)

1. SightGlass Vision Inc, Palo Alto, California, USA
2. Carol Chung Statistics Consulting Inc, Pacifica, California, USA
3. Visioncare Research Limited, Farnham, UK
4. Department of Ophthalmology, University of Washington, Seattle, Washington, USA

Date: Sep 2022

Reference: Rappon J, Chung C, Young G, Hunt C, Neitz J, Neitz M, Chalberg T. Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS). Br J Ophthalmol. 2022 Sep 1: bjophthalmol-2021-321005

[Link to open access paper]

Research examining high myopia and the functioning of retinal signals found that long (red) and medium (green) wavelength retinal cones are involved in the emmetropisation process¹ and that high contrast patterns in signalling between normal and defective cones may influence axial growth.^1,2

Concern that environmental contrast could be a signal for axial growth led SightGlass Vision to develop Diffusion Optics Technology (DOT) in order to reduce signal differences between adjacent cones.

The Control of Myopia using Peripheral diffusion lenses Efficacy and Safety Study (CYPRESS) study is an ongoing, 36-month long randomised controlled trial across 14 sites. The aim of the study is to assess the change in axial length (AL) and spherical equivalent error (SER) from baseline and to evaluate the efficacy and safety of 2 trial DOT design spectacle lenses versus a control lens. This report outlines the results from the first year of wear.

The 256 study participants were children aged from 6 to 10yrs with SER of -0.75 to -4.50D and with less than 1.25D astigmatic correction.

They were randomised to receive spectacles glazed with either test lens 1 or 2 or the control lens. There was a further stratification within each study group to reflect the age and potential rate of myopia progression of the participants.

The DOT technology consists of microscopic translucent diffusers which provide light scatter and reduce contrast and are applied across the whole of the lens surface other than the central 5mm. The diffusers have 0.365mm spacing on test lens 1 and a closer spacing of 0.24mm on test lens 2. The lenses were worn for at least 10 hours daily.

• The average age of the children was 8.1yrs and 58% were female. The mean SER at baseline was -2.01D (manifest refraction) and -1.94D (cycloplegic autorefraction). Mean baseline AL was 24.02mm.
• After 12-months, test lens 1 gave a mean reduction in SER of -0.40D versus control (74% reduction) and test lens 2 gave -0.32D less progression (59% reduction versus control). The difference in AL versus control for test lens 1 and test lens 2 was 0.15mm and 0.10mm, respectively.
• Parental and subject questionnaires showed compliance with the requested wear time and that the lenses were well tolerated.

In safety terms, only 17 out of 55 device deficiencies across all 3 study groups were lens related and none were serious adverse events.

These 12-month interim results from the CYPRESS study have shown DOT technology lenses are a safe and effective myopia treatment option for young children, compared to standard single vision lenses.

• The 12 month interim data has shown that that DOT technology is effective in modulating retinal contrast, slowing myopia progression and axial growth within the first year of wear
• This is the first data published for effective myopia control with spectacle lenses in children from 6 to less than 8 years of age, as the two other novel myopia control spectacle lens designs (DIMS and H.A.L.T. Technology) reported clinical trial results in children aged 8 to 13 years. This is important data as this age group tends to show some of the fastest myopia progression.^3,4
• The lenses were also shown to be particularly effective in younger children aged 6-7 years, where test lens 1 gave an average of 0.56D less refractive progression versus the control group over one year.
• The children wearing the lenses tolerated them well with few issues, providing a simple and safe approach to myopia control treatment.

1. The children in this study were all 10yrs or younger. Since younger children are accepted as having faster axial length growth and myopia progression,^3,4 the findings cannot be extrapolated to older children without further research.
2. The children were recruited across 14 sites from a diverse population in North America. Since nearly 75% of the children were white, though, future research would explore the efficacy of the lenses for an age-matched cohort with different ethnicities and progression rates.
3. Around 20% of children removed their glasses for near vision activities, these primarily being reading and writing. The authors cited that removal of spectacles for reading could have had an influence on efficacy of the glasses.
4. With test lens 1 (called DOT 0.2 commercially) showing the stronger results over the first year of the study, the second and third year results to come will confirm this as the superior lens design. Note that the second year results have been published in Abstract Form, in mid 2022.

Title: Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS)

Authors: Joe Rappon, Carol Chung, Graeme Young, Christopher Hunt, Jay Neitz, Maureen Neitz, Thomas Chalberg

Purpose: Mutations in the L/M cone opsin gene array cause abnormally high perceived retinal contrast and the development of myopia. Environmental factors may also lead to high visual contrast and cause myopia.  Diffusion optics technology (DOT) lenses are designed to reduce contrast signalling in the retina and slow myopia progression

Methods: The Control of Myopia Using Peripheral Diffusion Lenses Efficacy and Safety Study (CYPRESS, NCT03623074) is a 36-month, multicentre, randomised, controlled, double-masked trial evaluating two investigational spectacle lenses versus control lenses in myopic children aged 6-10, with a planned interim analysis at 12 months. The primary endpoints are change from baseline in axial length (AL) and spherical equivalent refraction (SER).

Results: 256 children (58% female; mean age at screening, 8.1 years) were dispensed spectacles. Across all groups, baseline averages were AL 24.02 mm (SD±0.77 mm), SER −2.01 D (SD±0.9 D) using manifest refraction, and SER −1.94 D (SD±1.0 D) using cycloplegic autorefraction. At 12 months, mean difference in SER progression for test 1 versus control was −0.40 D (p<0.0001), representing a 74% reduction and −0.32 D for Test 2 (p<0.0001), representing a 59% reduction. The difference in AL progression for test 1 versus control was 0.15 mm (p<0.0001) and test 2 versus control was 0.10 mm (p=0.0018).

Conclusions: 12-month results from this ongoing trial demonstrate the safety and effectiveness of DOT spectacles for reducing myopic progression

[Link to open access paper]