Understanding RingBoost technology in soft contact lenses

The use of soft contact lenses with multi-focus optics to slow myopia progression has seen enormous progress in recent times, from the first case report published in 2008¹ and first clinical trial published in 2013,² both utilizing commercially available designs originally for presbyopia. Since then, a variety of soft contact lens designs specifically for myopia have emerged and been tested in randomized controlled trials. These include defocus-incorporated,³ dual-focus concentric,⁴ and extended-depth-of-focus⁵ designs.

The newest evolution of myopia controlling soft contact lenses involved extensive preclinical testing to develop prototype designs incorporating concentric annular zones with noncoaxial relative plus power.⁶ Termed RingBoost™ technology, it was developed by Johnson and Johnson Vision with the aim to increase the relative plus power or 'Add' power for increased treatment efficacy while minimizing the impact on vision.⁶ This article will explore the RingBoost™ technology design and efficacy to slow myopia progression in children.

Dual-focus contact lenses³ incorporate an annular 'Add' power in the lens optics which provides the presumed mechanism for slowing myopia. This Add power brings light to focus at a single point in front of the retina. In the RingBoost™ technology soft contact lenses, relative plus power is incorporated to create myopic defocus as well; however, these plus power zones do not create a point focus. Instead, a ring focus is formed in front of the retina, forming off the central axis of vision.⁶

Animal models indicate that the amount of peripheral defocus induced by an optical treatment influences the amount of eye growth that occurs.^7,8 The Bifocal Lenses in Nearsighted Kids (BLINK) study showed that a high add power (+2.50D) in center-distance multifocal soft contact lenses had a myopia control effect, where a medium add power (+1.50D) did not.⁹ You can read more about the dose-response in soft contact lenses in our article Is There A Dose Response In Myopia Control?

Following from this theory, increasing Add power is thought to provide more myopic defocus and so a greater myopia control effect.^6-8 In multifocal or multi-zone soft contact lenses, the impact of increasing Add powers on vision is a limiting factor: due to the singular point focus at the line of sight, visual acuity and contrast sensitivity is impacted up to +2.00D or +3.00D add powers and haloes typically experienced.¹⁰ In RingBoost™ technology, Add powers are introduced into the contact lens as torus shapes rather than in a spherical shape, which creates a ring-focus in a noncoaxial position, around the line of sight.^6,10

In the multisite randomized clinical trial of the RingBoost™ soft contact lenses, 200 children aged 7- to 12-years old with spherical equivalent refractive error (SER) between -0.75D to -4.50D were recruited. Four types of soft contact lens designs were compared:

• EE: EE is prototype 1 of the RingBoost™ technology and was designed to "enhance efficacy" - it has 2 concentric, annular treatment zones of +7.00D non-coaxial plus power. In this EE prototype, the plus power is positioned closer to centration. It also features a +10.00 D co-axial treatment zone for greater efficacy.
• EV: EV is prototype 2 of the RingBoost™ technology and was designed to "enhance vision" - it also has 2 concentric, annular treatment zones of +7.00D non-coaxial plus power. However, in this EV prototype the plus power is positioned further away from centration.
• DF: Dual-focus contact lenses
• SV: Single vision contact lenses

Data at 6 months revealed that the EE lenses provided the most myopia control effect out of all the designs investigated as measured by axial length and spherical equivalent autorefraction (SECAR) - see the graph below. The EV lenses were comparable to the dual-focus lens design in terms of myopia control efficacy.⁶

Figure 2 from open access paper Randomized Trial of Soft Contact Lenses with Novel Ring Focus for Controlling Myopia Progression⁶ with the following caption: "Unadjusted mean (standard error) change in (A) axial length (AL) and (B) spherical equivalent cycloplegic autorefraction (SECAR) by lens type across time. The 2 measures of AL at 26 weeks represent noncycloplegic (dark gray) and postcycloplegic measures (black). D = diopter; EE = enhanced efficacy lens group; EV = enhanced vision lens group; DF = dual-focus lens group; SV = single-vision lens group."

At this stage, only 6-month data is available. As we know, treatment effect is not constant over time: but a good indicator of long-term efficacy is early strong myopia control performance. Myopia control treatments typically demonstrate this in the first 6 to 12 months of use.¹¹ Read more about this in our article Can We Predict Long-Term Efficacy From Short-Term Outcomes?

At all study visits, in all the contact lens designs (EE, EV, DF and SV) participants achieved a visual acuity of 0.00 logMAR (6/6 or 20/20 equivalent). 90% of participants expressed a high level of satisfaction with their visual experience; however, both the EE and DF groups experienced a higher incidence of haloes and other visual disruptions. At the 1-week mark, approximately 12% of participants reported experiencing haloes, which decreased to 5-7% after 26 weeks. The EE group had a lower occurrence of ghosting (2%) compared to the DF group (14%) after 26 weeks.⁶

Subjective visual experience may be age-dependent. A recent cross-over study investigated the visual differences between different soft contact lens designs for myopia control. Participants aged 7- to 17-years old were given single vision contact lenses to wear for 1 week. Over a 6 week period, they were then given either the RingBoost™ prototype EE, the RingBoost™ prototype EV or dual-focus soft contact lenses and switched every 2 weeks. It was found that teenagers were more judgemental with regards to vision quality than children, with this age group being more critical about their visual experience with the EE and dual-focus lenses.¹²

In a study evaluating the effect on accommodation, the RingBoost™ lenses were compared to dual-focus concentric, center-distance multifocal and single vision soft contact lenses, as well as standard spectacle lenses. It was found that the accommodative responses from the RingBoost™ wearers were statistically equivalent to single vision contact lenses, where dual-focus lenses showed either a smaller or larger accommodative response compared to single vision depending on measurement type. Center-distance multifocal contact lens accommodative responses were reduced compared to single vision.¹³

The RingBoost™ design offers a soft contact lens myopia control option that provides a high level of myopic defocus while still maintaining good vision and visual function.^6,10,12,13 While continued research is underway to reveal how the RingBoost™ technology performs over longer time periods, early data indicates promising potential as a robust myopia control treatment.