Deep dive Into the PROTECT study - Q&A with Dr Ashley Tuan

PROgressive Myopia Treatment Evaluation for NaturalVue Multifocal Contact Lens Trial (PROTECT) is a three-year, multinational, double-masked, randomized controlled trial (RCT) evaluating the effectiveness and safety of NaturalVue® Multifocal, a commercially available daily disposable soft multifocal lens, for myopia progression control in children. While there is good retrospective data on the NaturalVue Multifocal for myopia management,^1,2 we wanted to perform a prospective analysis on the NaturalVue Multifocal to build that foundation. It would also allow for more control over variables and ensures that data is collected in a standardized manner.

Year one results have shown that the children wearing NaturalVue Multifocal (NVMF) had significantly slower myopia progression rate and axial length elongation rate than the control group, with children wearing single vision contact lenses. About 2/3 (64%) of the children (baseline age 8-<13, cycloplegic spherical equivalent autorefraction -0.75 to -4.00D) wearing NVMF experienced no meaningful progression of myopia (≤0.25 D progression) and 58% of the children wearing NVMF had axial length growth similar to age-matched emmetropic kids. On average, there was a slowing in myopia progression of 0.41D (71%) and a reduction of axial elongation of 0.17mm (61%).³

There was no issue keeping the study lenses on these kids’ eyes long enough to receive the desired treatment time (10 hours a day, 6 days a week). On average, both groups reported wearing their assigned lenses 11-12 hours a day, 7 days a week; this finding is not surprising as these children had spectacle-level vision and stereopsis wearing NVMF.

We are glad to see PROTECT’s 1-year outcomes corroborate with the published retrospective NVMF studies. That means NVMF has robust performance in the real world, where the different patient population, lifestyle, and modes of practice could come into play.

We are continuing to analyse the collected data. You may have noticed that many myopia control studies reported both Unadjusted and Adjusted treatment effects:

• Unadjusted treatment effects are the straight averaging of the outcome measures from the study population. We know there are other factors that may also influence the progression of myopia (covariates), such as age, gender, ethnicity etc. 
• Adjusted treatment effects come from applying a statistical method (linear-mixed model) that takes into account the covariate values associated with each study subject. In other words, it removes the potential impacts from the covariates so that the Adjusted results can better represent the true effect of the intervention being studied. Therefore, you see Adjusted data being reported in peer-reviewed journals and is required by some regulatory agencies, such as the FDA.

We are also looking into the impact of accommodative lag and its relationship with myopia progression. In addition, what do the children think of wearing their assigned lenses when it comes to vision, comfort, and if it affects their daily activities? We have administered PREP2,⁴ a validated questionnaire that was used during the BLINK study,⁵ and we will share our analysis in the near future. 

The real-world retrospective studies reported no significant change in refractive error in either the first year or the following years. The PROTECT study is in its second year and we are looking forward to the 2-year results to see how well they match the published retrospective real-world data. 

NaturalVue Multifocal is a centre-distance lens. Its optic is extremely aspheric; the power profile is in the shape of a catenary curve with +8.00 D of ADD by the time it reaches 6mm diameter from the centre of the lens.⁶ The smooth progression of relative plus, instead of an abrupt transition, enables wearers to benefit from a high magnitude of myopic defocus and still enjoy spectacle-level vision and stereopsis. This optical design also delivers relative plus for kids with small pupils or when they are playing outdoors in bright light.

Finally, NVMF’s aspheric optic generates an extended depth-of-focus channel on the visual axis, that can correct astigmatism (clear images at two different focal points) like it corrects presbyopia (clear images for various vergences from distance to near). 

Every myopia management superhero needs a collection of tools in their utility belt to meet each child's needs. In fact, different interventions may be utilized as the child ages and their lifestyle or interests change. 

NaturalVue Multifocal daily disposable soft contact lens is indicated for myopia progression control in many regions around the world. It has been proven to work in both a randomized controlled clinical setting and in real-world practices. NVMF’s distance power is available in spherical powers from +4.00 to -12.25D in 0.25D steps, which enables a practitioner to provide the right prescription needed by the patient across a large range of patients. Even younger myopic astigmats benefit as the lens is approved for up to 2.00 DC astigmatism correction. 

Given that the treatment area (relative plus) starts building 5µm (0.005mm) from the centre,⁶ the lens can treat a wide range of pupil sizes under a wide range of lighting conditions; while NaturalVue delivers excellent visual quality and is comfortable to wear all day. 

NaturalVue Multifocal can benefit most children and can also be an excellent choice for those whose lifestyle places great demand on visual clarity needed for excelling in school, sports, or the arts.