天然视频多灶性隐形眼镜是每天设计用于长期和近视控制的一次性一次性。据称，带有“单个高级添加”的中央距离设计可满足+3.00的增加要求。采用独特的设计，以下是对自然景点光学设计和近视控制功效的研究的探索。
The optics of NaturalVue
一个典型的中心距多病灶的隐形眼镜will have an 'optic zone' of central spherical power, representing the back vertex power of the contact lens. The back vertex power is usually chosen to match the best vision sphere of a spectacle refraction, after accounting for any vertex distance correction. The NaturalVue contact lens, however, features a continuous change in power 'almost immediately from the lens centre' as indicated in a 2020 ARVO abstract.1
这项研究在德克萨斯州休斯顿大学进行的，比较了Coopervision Biofinition和Proclear Center距离的电力概况+2.50添加了与自然概况的多焦点。发现两个为Coopervision镜头的中央视频区域半径为1.5mm，然后增加了1.25-1.5d的功率从1.5mm降至2mm的半径。然后，对于低负镜头，将这种“添加”功率保持在大约3.8毫米的半径上，并减少了最小的功率镜头，直到到达视位的边缘。”相比之下，天然vue多灶性CL'几乎立即从镜头中心开始增加加电功率，直到达到2.6 mm的最大测量平均功率加上3.31±0.36 d。从半径为2.6毫米到3.0毫米的半径，加上功率平均降低为4.11±0.20D。然后通常从3毫米的半径延长到光学区域。1
While this is a peer-reviewed abstract so not yet available in full paper form, this description of the NaturalVue power profile is in alignment with that graphically indicated by VTI, which represents the power profile to a 2.5mm radius.The blue line in the plot below shows the radial / sagittal / axial power profile(interchangeable terms) in agreement with the University of Houston abstract.
The red line shows the instantaneous / tangential power profile.You may be familiar with this concept if you fit orthokeratology lenses - both methods of topography description, or in this case a power profile, are useful but provide different information.
In 2019,VTI undertook and released work utilizing the NIMO wavefront sensorto represent the instantaneous power profile of the lens, as distinct from the radial / sagittal power profiles typically reported. This is represented in the graphic below, which is an excerpt from theNaturalVue Multifocal Power Profile PDF,from vtivision.com.
To read more about instantaneous versus radial power profiling from VTI,click this link。It describes more about how instantaneous versus radial / saggital power profiling is useful for different multifocal lens designs. The sum total? The NaturalVue lens is described as aunique design with no spherical regions within the power profile。From thewebsite：
The progression of plus power in NaturalVue®Multifocal contact lenses is significant enough to induce peripheral blur. This generates the virtual pinhole aperture to create an Extended Depth of Focus.
自然景度如何工作？
The absence of a spherical central optic zone in the NaturalVue lens is designed to create peripheral blur and a 'virtual pinhole aperture'。这解释了长老会的“单一添加”适用性。With regards to myopia control, this adheres to theperipheral defocus theory, whereby the peripheral retina receives myopic defocus as a slow-down or stop signal for eye growth. This has been shown extensively in animal models - Earl Smith III is arguably the world's leading researcher in this area and you can read asummary lecture of his here。
光学质量结果
Another2020 ARVO Abstract发现r的造型etinal image quality "through the NaturalVue and Biofinity CD lenses were comparable for all viewing distances." By comparison, "The central clear portion of DIMS spectacle lenses results in better image quality compared to the soft contact lens options evaluated. However, the peripheral portion substantially degraded image quality for all viewing distances."2
这意味着，尽管具有复杂的光学元件，并且在天然案例中没有球形中央视觉区域，但对于典型的多焦点隐形眼镜，光学质量和敏锐度应相似。还值得注意的是，由于隐形眼镜与眼睛移动，因此“中央”或“外围”观看体验与控制眼镜镜头的近视相同。
Astigmatism 'masking' or 'correcting'?
The NaturalVue multifocal lens can also be used for presbyopia, in which case the天然拟合指南advocates selecting patients with no more than 1D of astigmatism. The more extensively detailedProfessional Fitting and Information Guide,though, states that "The [multifocal] lenses may be worn by persons who exhibit astigmatism of 2.00 diopters or less that does not interfere with visual acuity."
This potential for correcting higher levels of astigmatism than is typical in spherical multifocal CLs is likely due to the unique optics of the NaturalVue lens, where the 'extended depth of focus' design is explained to create a 'virtual pinhole aperture'。因此，它可能是“部分纠正”而不是“掩盖”散光。“掩盖”是一个通常用于球形隐形眼镜校正中残留散光的术语，尽管已反复证明它不有效。在临床案例中阅读更多有关此的信息天然视频多灶性隐形眼镜 - 散光“掩盖”或“纠正”？
Myopia control and NaturalVue
The absence of a spherical central optic zone in the NaturalVue lens is designed to create peripheral blur and a 'virtual pinhole aperture'。这解释了长老会的“单一添加”适用性。关于近视控制，假定的机制遵守peripheral defocus theory, whereby the peripheral retina receives myopic defocus as a slow-down or stop signal for eye growth. This has been shown in animal models - Earl Smith III is arguably the world's leading researcher in this area and you can read asummary lecture of his here。
Animal studies
Two studies on the NaturalVue lens design were undertaken on chickens at the University of Waterloo as proof of concept. The first compared two lens designs to determine the most effective peripheral add gradient.3第二项研究表明，通过两个测试透镜设计，轴向进展的镜头诱导的小鸡的近视可能会减慢，并在折射过程中停止甚至逆转。4
Human studies - retrospective case series data
In 2018, Cooper et al5published aretrospective case series analysison 32 myopic patients across 10 practices, with patients completing between 6-25 months of lens wear with a mean of 11 months. The children progressed -0.90D+0.57D in the year before initiating lens wear, which reduced to -0.03D+佩戴天然票时，每年的年度进展为0.17d。32岁的只有一个孩子继续增加其近视的进展。这项初步研究不包括轴向长度的度量。
Also in 2018, Aller presented anARVO abstract6of retrospective data from his single practice. Twenty-six consecutive patients with a mean age of 11.8 years (range 6-22 years) were switched from a variety of corrections (including single vision, orthokeratology, atropine and other multifocal contact lenses) into NaturalVue. Myopia progression prior to fitting NaturalVue, and once wearing the new lens, were calculated. Progression before NaturalVue was 'adjusted to a six month rate' of -0.45+0.42d，拟合到平均值为0.00之后+0.30d。
Eleven of these children had axial length data available pre- and post-NaturalVue fitting, which showed a reduction from a mean 0.13+0.08mm progression to 0.07+0.07mm。作者报告说，即使看着正在接受近视治疗的儿童群体，也发现了这种统计学意义的减少。
Aller, Cooper and co-authors presented anotherretrospective study abstract at the 2019 BCLA meeting。This dataset included 141 children who exhibited at least -0.50D change in the year before commencing treatment and a mean progression of -1.07+0.83D.7作者报告说，与所有时间点相比，与基线相比，RE变化的减少约为1.00D，这对基线来说是统计学上的显着变化。治疗前儿童的轴向长度生长在0.03-1.03mm之间，平均为0.42+0.33mm. This reduced to an average change of 0.19+0.17mm at the 12-17 month mark, which was reported as a 55% reduction in progression.
在2020年全球近视研讨会,VisioneeringTechnologies presented additional clinical data showing myopia control over a longer time period. This was reported on in a sponsored article on近视管理的审查；五年的新临床证据：自然景观多灶。It continues on from the retrospective 2018 study by Cooper et al. and this time included 153 children followed from between 6 to 59 months across multiple locations. They reported a 0.90D decrease in refractive progression when compared to the children’s historical progression before commencing treatment. Thirty-six of these children had their axial length measured, and had an average change of 0.10mm per year. This cohort is continuing to be tracked, so future data can be expected.
Figure 2 from Cooper et al 20185with the following caption:
'Individual data plots of baseline refractive error (spherical equivalent [SE] in diopters) versus follow-up time (months), both before and after wearing NaturalVue Multifocal for 6 to 25 months (right eye). The change in the y-axis indicates the change in refraction, the change in the x-axis indicates the number of months that each treatment was followed, and the gradient of each line indicates the amount of myopic progression both before and after treatment.'
What we know
自然有效性似乎具有近视控制效果。迄今为止提供的回顾性数据表明了现实世界中的临床观察结果，如果个体患者及其父母观察到折射率和轴向近视进展的放缓，这对该人来说是一个很好的结果。
What we don't know
Naturalvue的比较近视控制效果与其他可用产品或单一戴在对照组中。这些研究都不包括对照组，因此尚不清楚屈光或轴向进展的绝对减少。到目前为止，迄今为止提出的控制率与同一个体的固定后和贴合的比较，而不是在两个匹配的对照组和治疗组之间进行比较。由于近视的进展往往会随着时间而变慢，8比较在对同一个人进行干预之前和之后的进展可能总是显示出一定比例的放缓，这是由于年龄增长而带来的。
Where does NaturalVue fit in your myopia control toolkit?
The three clinical advantages of the NaturalVue multifocal contact lens are being a daily disposable, available in powers up to -12.25D, and potentially able to 'partially correct' up to 2D of astigmatism (provided good acuity is achieved).
A daily disposable is the safest modality of myopia controlling contact lenses. Read more aboutContact Lens Safety in Kidsvia the link.
While informed consent is an important component of any myopia control strategy, it's important to note that managing high myopia (more than 5-6D) does bring its own particular challenges due to lack of research evidence on myopia control efficacy in general, as well as the importance of ocular pathology risk management. Contact lenses are an important part of vision correction for high ametropia, though, hence it's beneficial that the NaturalVue lens offers an option for myopia correction and a potential for myopia control for high and very high myopes.
临床case studies on NaturalVue
About Kate
Dr Kate Giffordis a clinical optometrist, researcher, peer educator and professional leader from Brisbane, Australia, and a co-founder of Myopia Profile.
This educational content is brought to you thanks to unrestricted educational grant from
References
- Nyarko Nti A, Ritchey ER, Berntsen DA. Power profiles of center-distance multifocal soft contact lenses. Invest Ophthalmol Vis Sci. 2020;61:1180.（关联）
- Sah RP, Jaskulski M, Singh NK, Kollbaum PS. Effect of multifocal optics designed for myopia control treatment on retinal image quality in children. Invest Ophthalmol Vis Sci. 2020;61(7):563.（关联）
- Woods J et al. Inhibition of Defocus-Induced Myopia in Chickens. Invest Ophthalmol Vis Sci. 2013;54:2662-8.（关联）
- Irving, E. L. & Yakobchuk-Stanger, C. Myopia progression control lens reverses induced myopia in chicks. Ophthalmic Physiol Opt. 2017;37:576-84.（关联）
- Cooper J et al. Case Series Analysis of Myopic Progression Control With a Unique Extended Depth of Focus Multifocal Contact Lens. Eye Contact Lens. 2018;44:e16-24.（关联）
- Aller TA. Myopia progression before and after fitting with the NaturalVue multifocal contact lens – a case series analysis. Invest Ophthalmol Vis Sci, 2018;59:4770.（关联）
- Aller TA et al. Myopia management with NaturalVue (etafilcon a) Multifocal 1 day contact lenses: continuing evidence from clinical practice. Contact Lens Anterior Eye. 2019;42:E24.（关联）
- Donovan L, Sankaridurg P, Ho A, Naduvilath T, Smith EL 3rd, Holden BA. Myopia progression rates in urban children wearing single-vision spectacles. Optom Vis Sci. 2012 Jan;89(1):27-32（关联）
