Myopia Management
What is myopia?
Myopia causes blurry vision in the distance, often called ‘short-sightedness’ or ‘near-sightedness’. Objects are being focused in front of the retina in the back of the eyeball as shown below. Glasses and contact lenses can help adjust the focusing point onto the correct spot on the retina. Not correcting myopia leads to constant blurry vision and eyestrain.
Why is myopia a concern?
The rate of myopia is growing across the world, increasing from 22% of the world’s population in 2000 to 33% in 2020 – half of the world’s population is expected to be myopic by 2050.1 Most myopia is caused by the eye length growing too quickly in childhood. The eyes are meant to grow from birth until the early teens and then cease, but in myopia, the eyes grow too much and/or continue growing into early adulthood. Once a child becomes myopic, their vision typically deteriorates every 6-12 months, requiring a stronger and stronger prescription. Most myopic children tend to stabilize by the late teens and early 20s.2 Excessive eye growth raises concern because even small amounts of stretching can lead to an increased likelihood of vision- threatening eye diseases in later life, such as myopic macular degeneration, retinal detachment, and cataract.3,4
Why manage myopia in children?
Myopia progresses fastest in younger children, especially those under age 10.5 This means that the most important opportunity to slow eye growth is when children are younger. Myopia management aims to apply specific treatments to slow excessive eye growth to a lesser rate. Experts agree that myopia management should be commenced for all children under age 12,6 and typically continue into the late teens.7
The short-term benefit of slowing myopia progression is that a child’s prescription will change less quickly, giving them clearer vision for longer between eye examinations. The long-term benefit is reducing the lifetime risk of eye disease and vision impairment. This risk increases as myopia does3 with the good news being that reducing the final level of myopia by only 1 diopter reduces the lifetime risk of myopic macular degeneration by 40% and the risk of vision impairment by 20%.8
Treatments for slowing myopia progression
Standard, single-focus long-distance spectacles or contact lenses do not slow down the progression of childhood myopia.8 Instead, specific types of spectacles, contact lenses, and eye drops called atropine have been proven to slow myopia progression in children.6
The best option for your child will depend on their current prescription and other vision and eye health factors determined in their eye examination. It is important to note that no treatment can promise the ability to stop myopia progression in children, only to slow it down.
Spectacles
Standard single-focus spectacles do not slow the worsening of childhood myopia but specific designs do. Myopia-controlling spectacles can both correct the blurred vision of myopia and work to slow down myopia progression. Executive type bifocals have shown a moderate effect in slowing progression of myopia. The Essilor Stellest lens and Hoya MiYOSMART lens are specially designed for myopia progression and have been shown to offer the highest currently possible efficacy for myopia control, ranking alongside Ortho-K and soft contact lens design for myopia control. 15 Sometimes, low dose atropine treatment is added to myopia controlling spectacle lenses treatment for increased efficacy. These glasses are safe to wear, and adaptation is typically easy, with the only side effects being related to the limitation’s spectacles pose for sports and active lifestyles. UnfortunatelyThese lenses are currently not available in MO.
Contact lenses
Standard single-focus contact lenses do not slow the worsening of childhood myopia, but specific designs do. MiSight is the only soft contact lenses approved by the United States Food and Drug Administration (FDA) for specific purpose of myopia management. Paragon CRT is an Ortho-K lens approved by FDA for myopia management with the highest shown efficacy. These lenses can both correct the blurred vision of myopia and work to slow down myopia progression.
Risks and safety
Contact lens wear increases the risk of eye infection compared to wearing spectacles, with the risks being:
- 1 per 1,000 wearers per year for reusable soft contact lenses or overnight orthokeratology lenses9,10
- 1 per 5,000 wearers per year for daily disposable soft contact lenses9
With proper hygiene and maintenance procedures, this risk can be well managed – especially by avoiding any contact with water with contact lenses or accessories.11 Other side effects of contact lenses to control myopia can be a temporary adaptation to the different experiences of vision, which typically resolves in 1-2 weeks.
Benefits
- There are many benefits to children wearing contact lenses: Wearing contact lenses improves children’s self confidence in school and sport, and their satisfaction with their vision – as much as it does for teens12
- Children aged 8-12 years appear to be safer contact lens wearers than teens and adults, with a lower risk of eye infection13
- Children only take 15 minutes more to learn how to handle contact lenses than teens14
Orthokeratology contact lenses are worn overnight and removed upon waking, such that no spectacles or contact lenses are required for clear vision during the day. They can require more appointments for fitting than other types of myopia control treatment. Adaptation to the lens-on-eye feeling can take 1-2 weeks but shouldn’t affect sleep.17 There are significant benefits for water sports and active lifestyles, and since the contact lenses are only worn at home there is a low risk of them being lost or broken during wear. If orthokeratology lenses are decided on for your child a fitting appointment will be booked with additional training on the insertion and removal of the lenses.
Soft myopia-controlling contact lenses (MiSight) are worn during waking hours and are daily disposable. They typically require more appointments for fitting than spectacles but less than orthokeratology. Adaptation to the lens-on-eye feeling typically occurs in a few days. There are benefits in safety with daily disposables being the safest modality, and the number of lenses retained meaning loss or breakage is less of a practical issue.
With proper contact lenses care and hygiene, the risk of infection when wearing contact lenses is very low. For best safety outcomes, MiSight and ortho-k lenses should only be fit by an experienced and appropriately qualified optometrist or eye doctor. 15
Atropine eye drops
Atropine eye drops in strong concentrations (typically 1%) are used to temporarily dilate the pupil of the eye and stop the focusing muscles from working in a variety of clinical applications. Atropine eye drops for myopia control, though, are a low concentration (0.01% to 0.05%) with much fewer side effects. Atropine has been found in several studies to reduce the progression of myopia, meaning that children who were given the medication did not become as myopic as the children without the medication.
In USA, atropine is not approved for myopia control but is used “off-label”, meaning that the doctor can decide to use an approved drug for a non-approved reason. Low-dose daily aspirin for protection against heart problems is probably the most cited example of “off-label” use of a drug but there are many others. Diluted atropine drops can only be made by specialty compounding pharmacies. In a recent large study, only a very small percentage of children complained of problems with low concentration atropine, and glasses can reduce symptoms if your child notices poor reading vision or lights seem too bright. Additionally, for patients with fast progression, atropine may need to be applied in conjunction with contact lenses treatment to increase the efficacy.
These adverse effects will be monitored at follow-up visits and the dosage can be altered to minimize any adverse effects. If the program is beneficial to your child, we will typically continue treatment during your child’s growth years as determined by the doctor. Therapy typically continues until age 18-20 or until the patient shows stability in their prescription (indicated by two years without significant change). In some cases, therapy may continue beyond age 18. Atropine drops will be tapered at the end of the treatment, and there may be a small increase in myopia called a rebound effect. Spectacles or contact lenses are still needed to correct the blurred vision from myopia, as atropine only acts to slow myopia progression.
Risks and safety
The risks and side effects of atropine are as follows:
- Potential side effects of increased sensitivity to light due to larger pupil size, which is typically resolved with light-sensitive glasses or sunglasses. One study found around a third of children requested these types of glasses, but this was the case even in the placebo (untreated) group.15
- Problems with close-up focusing, which is typically resolved with glasses providing a stronger power for reading. One study found this only occurred in 1-2% of children treated with low- concentration atropine.15
- Eye irritation or mild allergy, which can occur in 2-7%,15 although this can depend on the formulation of the atropine.
Atropine can be toxic and even fatal to small children if it is ingested in high quantities by mouth, but high- quantity absorption via the eye is unlikely.16 Medication safety in the home is extremely important.
Benefits
Atropine eye drops are typically used at night-time, before sleep, so are only utilized in the home environment. They are also ideal if the effective spectacle or contact lens options for myopia control are not suitable or not available for your child.
Healthy lifestyle is the best way to prevent myopia progression. It is recommended that every child gets at least 2 hours of outdoor activity everyday, proper light setting and posture for near work with frequent breaks, adequate amount of sleep to allow proper development of the eyes, body and mind. Sunlight exposure is a free and readily available treatment for myopia progression.
近视管理
全球估计有14亿的人在2000年有近视。这相当于全球总人口的23%。但等到2050年时,研究人员预测这个数字会大幅上升至480万,影响全球49.8%的人口。好消息是,有方法能够保护您的孩子不会落到这个统计数据的一员。关键之一可能是鼓励您的孩子关闭电子装置并到户外活动。
研究指出,预测的近视增加主要是由生活方式的改变所促使。其特征是近距离工作活动增加,例如使用电脑和携带型电子装置,包括智能手机。其他提出的近视风险因素包括长时间花在教室中以及较少时间在户外。
虽然大多数有近视者的视力可以通过眼镜和隐形眼镜进行矫正,但高度近视会增加白内障、青光眼、视网膜剥离和近视型黄斑部病变等眼睛疾病的风险,这些都可能导致无法逆转的视力丧失。
虽然目前尚未发现彻底的近视治愈方法,但眼科医生可以提供几种或许能减缓近视恶化的治疗。这些治疗能引发眼睛结构和聚焦的改变,以降低与近视发展和恶化相关的压力和疲劳。
为什么推荐对小孩进行近视控制呢?因为减缓近视的恶化能够让您的孩子不会发展成需要佩戴厚重矫正型眼镜,且减少日后严重眼睛问题(例如白内障甚至是视网膜剥离)以及相关的深度近视导致的风险。
目前有四种治疗显示出对控制近视的前景(各有各的好处):
阿托平(Atropine) 散瞳眼药水:
阿托平一般用于瞳孔扩散。目前FDA没有批准低浓度阿托平用于近视控制,但是有很多研究显示低浓度阿托平可以有效缓解近视加深。
低浓度阿托品常用的浓度有0.01%、0.02%、0.05%等。浓度越高,效果越强,但是畏光或调节受影响的不良反应就越明显,停药后的反弹也会越明显。一项比较各种阿托品浓度(范围从 0.01% 到 1%)的试验的网络荟萃分析发现,0.01%-0.05%的阿托品滴眼液相对不良反应最小,0.05%在减缓近视加深方面最有效。
低浓度阿托品的主要不良反应有瞳孔散大、畏光反应和眼压升高 ,调节能力和近视力下降,过敏反应,刺激性反应。随着浓度升高不良反应的发生率会增加。
禁忌症包括对莨菪碱成分过敏、患青光眼或有青光眼倾向(浅前房、房角狭窄等),颅脑外伤、心脏病(特别是心律失常、充血性心力衰竭、冠心病、二尖瓣狭窄)等人群禁用。调节力低下、低色素者(如白化病)等慎用,部分伴有畏光症状的眼病(如角膜炎)可待痊愈后使用。
针对已经近视的儿童,低浓度阿托品滴眼液可以控制近视,但是并不能矫正视力,所以仍然需要戴眼镜。如果单一防控手段效果不佳,或者想要获得更好的防控效果,考虑多种防控手段联合,如角膜塑形镜/多焦点软性角膜接触镜/周边离焦矫正眼镜联合低浓度阿托品。
多焦隐形眼镜(MiSight):
MiSight 是一次性每日即弃近视控制软性隐形眼镜及其特殊的光学设计隐形眼镜类型的产品。在矫正视力的同时,减缓近视的加深速度。临床结果显示,配戴MiSight多焦点软性接触镜可以有效减缓眼轴变长,控制近视度数加深。一般较方便日常生活,对于喜欢各类户外活动或球类活动的小朋友来说,可谓相得益彰。另外,因为它每日即弃、干净卫生,而且软性镜片较柔软舒适,这些特性都特别受家长和小朋友欢迎。只要保持清洁,并且日常更换隐形眼镜,佩戴隐形眼镜是没有任何危害的。
角膜塑形术(“ortho-k”):
角膜矫形术(Ortho-K,俗称OK镜)是一种非手术矫正视力的方法,通过佩戴特制的高透氧度硬性隐形眼镜(角膜矫形镜),以压力慢慢改变角膜弧度,使角膜中央部分变得平坦,从而让外界光线重新聚焦到视网膜上,实现清晰的影像。然而,角膜具有一定的弹性,这种曲率改善并不是永久性的,不能彻底根治近视。一旦停止佩戴,清晰视觉效果将在数天内消失。因此,需要长期定时在晚间佩戴角膜矫形镜(OK镜),以维持清晰视觉效果。
另外,角膜形状改变后,眼球聚焦物体时,中心影像会被聚焦在视网膜上,周边影像则会被聚焦在视网膜的较前方,产生「周边离焦」,有效预防眼轴变长,从而减缓近视和散光加速加深。有证据显示相较于在近视恶化高峰期间配戴眼镜或一般隐形眼镜的儿童,接受多年角膜塑型术的近视儿童可能在成年时有较低度数的近视。配戴ortho-k镜片的儿童相较于配戴眼镜的儿童,眼睛轴向加长速度减慢了43%。同时,配戴角膜重塑硬式透气型镜片的较年幼儿童相比较年长的儿童,有较大程度的近视恶化降低。
OK-镜是一种安全有效的视力矫正解决方案。然而,对OK镜的不当护理会增加眼睛感染和角膜溃疡的风险。眼部感染的危险因素包括镜片清洁消毒不当、卫生习惯不良和吸烟。遵循清洁程序,以及定期检查,可以将这种风险降至最低。
多焦眼镜(Essilor Stellest/Hoya MiYOSmart):目前这两种镜片还没有在密苏里州上市。他们只有在几个测试营业的城市有销售。
良好的生活与学习习惯是最有效的预防近视的方式。每天户外活动2小时、科学的用眼习惯、充足的睡眠,既可以防控近视,又能够促进孩子的身心健康成长。阳光是免费且安全的近视防控良药。
Full Reference List
- Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, Wong TY, Naduvilath TJ, Resnikoff S. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016 May;123(5):1036-42.
- COMET Group. Myopia stabilization and associated factors among participants in the Correction of Myopia Evaluation Trial (COMET). Invest Ophthalmol Vis Sci. 2013 Dec 3;54(13):7871-84.
- Flitcroft DI. The complex interactions of retinal, optical, and environmental factors in myopia aetiology. Prog Retin Eye Res. 2012 Nov;31(6):622-60.
- Tideman JW, Snabel MC, Tedja MS, van Rijn GA, Wong KT, Kuijpers RW, Vingerling JR, Hofman A, Buitendijk GH, Keunen JE, Boon CJ, Geerards AJ, Luyten GP, Verhoeven VJ, Klaver CC. Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia. JAMA Ophthalmol. 2016 Dec 1;134(12):1355-1363.
- Chua SY, Sabanayagam C, Cheung YB, Chia A, Valenzuela RK, Tan D, Wong TY, Cheng CY, Saw SM. Age of onset of myopia predicts risk of high myopia in later childhood in myopic Singapore children. Ophthalmic Physiol Opt. 2016 Jul;36(4):388-94.
- Brennan NA, Toubouti YM, Cheng X, Bullimore MA. Efficacy in myopia control. Prog Retin Eye Res. 2020 Nov 27:100923. doi: 10.1016/j.preteyeres.2020.100923.
- Gifford KL, Richdale K, Kang P, Aller TA, Lam CS, Liu YM, Michaud L, Mulder J, Orr JB, Rose KA, Saunders KJ, Seidel D, Tideman JWL, Sankaridurg P. IMI – Clinical Management Guidelines Report. Invest Ophthalmol Vis Sci. 2019 Feb 28;60(3):M184-M203. doi: 10.1167/iovs.18-25977.
- Bullimore MA, Brennan NA. Myopia Control: Why Each Diopter Matters. Optom Vis Sci. 2019 Jun;96(6):463-465.
- Stapleton F, Keay L, Edwards K, Naduvilath T, Dart JKG, Brian G, Holden BA. The Incidence of Contact Lens Related Microbial Keratitis in Australia. Ophthalmol. 2008;115:1655-1662.
- Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci. 2013;90:937-944.
- Arshad M, Carnt N, Tan J, Ekkeshis I, Stapleton F. Water Exposure and the Risk of Contact Lens-Related Disease. Cornea. 2019 Jun;38(6):791-797.
- Walline JJ, Gaume A, Jones LA, Rah MJ, Manny RE, Berntsen DA, Chitkara M, Kim A, Quinn N. Benefits of contact lens wear for children and teens. Eye Contact Lens. 2007;33(6 Pt 1):317-321.
- Bullimore MA. The Safety of Soft Contact Lenses in Children. Optom Vis Sci. 2017;94(6):638-646.
- Walline JJ, Jones LA, Rah MJ, Manny RE, Berntsen DA, Chitkara M, Gaume A, Kim A, Quinn N. Contact Lenses in Pediatrics (CLIP) Study: chair time and ocular health. Optom Vis Sci. 2007;84:896-902.
- All about eye glasses for Myopia Control: My kids vision. MyKidsVision. (n.d.). https://www.mykidsvision.org/knowledge-centre/all-about-eye-glasses-for-myopia-control
- CLEERE Study Group Early Childhood Refractive Error and Parental History of Myopia as Predictors of Myopia. Invest Ophthalmol Vis Sci. 2010 Jan; 51(1):
- Atropine for the treatment of childhood myopia: changes after stopping atropine 0.01%, 0.1% and 0.5%. American Journal of Ophthalmology. February 2014.
- Multifocal contact lens myopia control. Optometry and Vision Science. November 2013. Retardation of Myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Investigative Ophthalmology & Visual Science. October 2012.