Monovision的概念及其矫正老视的应用

Monovision（MV）概念已经有几十年的历史，应用于老视的矫正也有三十多年了，主要以接触镜应用最为广泛，近些年来随着屈光手术的广泛开展，应用MV技术设计手术矫正老视渐渐受到手术医生的青睐。     

晶状体手术矫正老视的治疗进展

老视是与眼睛调节能力下降密切相关的生理现象。不论年轻时屈光状态如何,老视都是人一生中必须经历的阶段。随着老龄化人口数量的增多,老视问题得到越来越多眼科工作者的关注,各种治疗老视的方法与技术也应运而生。现就晶状体手术用于矫正老视进行综述。     

应用Monovision矫正老视的研究进展

Monovision矫正方法常用于老视和老视前期患者,即一眼矫正看远,另一眼矫正看近,其机制是双眼间的模糊抑制,MV可应用于单焦点角膜接触镜,并且还可应用于人工晶状体植入术和PRK,LASIK等激光屈光手术中,以及目前最新的非激光手术—传导性角膜成形术。本文就MV矫正的机制、对双眼视力功能的影响以及研究进展作一综述。     

Monovision矫正老视研究进展

随着人类社会的老龄化,老视矫正问题对视光学工作者提出了日益严峻的挑战[1].目前所有的老视矫正措施,包括配戴各种双焦点与多焦点眼镜[2]、接触镜(contact lens,CL)[2～14]与手术[18～20]都难以保证患者在各距离都看清楚,仍需要其做出一定的妥协.     

老视及其矫正

老视是一种生理现象，不论屈光状态如何，每个人均会发生老视。随着人类社会的老龄化，老视的矫正问题成为我们日益严峻的挑战。本文拟就有关老视的调节机制及近年来一些矫正方法的原理、手术方式、临床应用结果作一综述。     

准分子激光手术矫正老视的研究进展

准分子激光手术是一种简单、安全、有效的矫正老视的方法,并有可能提供个体化的切削以提高老视患者的视觉质量.本文就老视的机制及治疗、准分子激光手术矫正老视的理论进展、手术方式、切削模式及效果评价进行综述.     

老视矫正手术的临床应用与展望

随着人们对生活质量的需求提高,老视问题越来越受到关注。像屈光不正矫正手术一样,老视的激光矫正治疗无论是设备开发还是临床手术的应用都逐年增多,如角膜的激光、角膜板层间镶嵌、角膜热重塑、巩膜气化等。但是老视又与屈光不正（近视、远视和散光）不同,到了一定年龄屈光度会相对稳定,而老视则与年龄有紧密的相关性。目前老视人群庞大,因此有许多人期待着安全、有效、可预测性强、远中近视力都能兼顾的老视矫治手术。     

未加矫正的老视与视力损害

老视虽不属于屈光不正的范畴,但未加矫正的老视可造成大量的近视力残疾.全球未加矫正的远视力损害患者达1.53亿,而未加矫正的老视的近视力残疾患者在2005年估计为4.1亿,远远超过了全球未加矫正远视力损害的人数,如不采取积极措施,到2020年未加矫正老视患者引起的近视力残疾可达5.63亿.同时,未加矫正老视患者的生存质量可明显受到影响.因而应重视未加矫正的老视引起的近视力残疾,对其干预途径主要是验配近用眼镜.     

老视矫正方法的研究进展

目的老视矫正方法的日趋多样化。配戴框架凸透镜是矫正老视最常见的方式,包括传统的单光（单焦）眼镜及近年出现的双光（双焦）、渐变多焦眼镜及衍射镜片。屈光手术矫正老视可分为角膜屈光性手术、眼内晶状体摘除联合可调节型人工晶状体（IOL）植入手术和巩膜屈光性手术。角膜屈光性手术包括激光角膜手术、角膜层闻植入物手术及传导性角膜成形术。鼎状体摘除联合可调节IOL植入术的IOL可分为单焦和多焦调节型两种,有引起眩光或光晕等视觉症状的情况,疗效需进一步观察。巩膜手术视觉完整性并不理想,且可能出现严重并发症,仍需临床观察。同时monovision（MV）被越来越多的引入到老视矫正手术中并且取得了较好效果。老视矫正方法的多样化为不同的需求者提供更多的选择。     

Monovision: the patient's perspective

We surveyed a group of 60 presbyopic subjects following eight weeks of monovision contact lens wear. The questions focussed on satisfaction with various aspects of visual performance, performance when driving, and general questions related to contact lens wear such as lens handling, care and maintenance and lens comfort. The subjects reported relatively high levels of satisfaction with visual performance, except in low light levels. Driving with monovision was also considered to be significantly worse at night than during daylight. Relatively few of the subjects had difficulties with lens handling, care and maintenance or lens comfort.     

传导性角膜成形术治疗老视眼的临床效果观察

目的:探讨应用单眼视原理采用传导性角膜成形术(Conductive keratoplasty,CK)治疗老视的临床效果、安全性及可预测性。方法:选择31例(40眼)有明显老视症状的患者,术前屈光度球镜+0.50~+2.50D,散光≤+0.75D,采用CK进行治疗,术后预期目标屈光度主导眼矫正为0.00~-0.50D,非主导眼术后目标屈光度为-1.50~-2.50D,且近视力≥0.5(J3),术后随访1a以上。结果:术后1a双眼裸眼远视力≥0.8且近视力≥0.5(J3)或近视力≥0.33(J4)者分别为61.3%,74.2%;与术前相比均有显著性差异(P<0.01);术后1a等效球镜屈光度与预期目标差值在±0.50D、±1.00D以内者分别为45.0%,82.5%;术后1a术眼散光度在±1.00D以内者为87.5%;术后双眼各空间频率对比敏感度与术前相比较差异无统计学意义(P>0.05);术后1a无最佳矫正视力下降,无严重干眼症的发生;术后1a90.3%的患者表示满意。结论:应用单眼视原理采用CK治疗老视取得了较好的临床疗效,但其远期疗效和稳定性有待进一步观察。     

Monovision: a review

In presbyopia, patients can no longer obtain clear vision at distance and near. Monovision is a method of correcting presbyopia where one eye is focussed for distance vision and the other for near. Monovision is a fairly common method of correcting presbyopia with contact lenses and has received renewed interest with the increase in refractive surgery. The present paper is a review of the literature on monovision. The success rate of monovision in adapted contact lens wearers is 59-67%. The main limitations are problems with suppressing the blurred image when driving at night and the need for a third focal length, for example with computer screens at intermediate distances. Stereopsis is impaired in monovision, but most patients do not seem to notice this. These limitations highlight the need to take account of occupational factors. Monovision could cause a binocular vision anomaly to decompensate, so the pre-fitting screening should include an assessment of orthoptic function. Various methods have been used to determine which eye should be given the distance vision contact lens and the literature on tests of ocular dominance is reviewed. It is concluded that tests of blur suppression are most likely to be relevant, but that ocular dominance is not fixed but is rather a fluid, adaptive, phenomenon in most patients. Suitable patients can often be given trial lenses that allow them to experiment with monovision in real world situations and this can be a useful way of revealing the preferred eye for each distance. Of course, no patient should drive or operate machinery until successfully adapted to monovision. Surgically induced monovision is less easily reversed than contact lens-induced monovision, and is only appropriate after a successful trial of monovision with contact lenses.     

模拟单眼视对视觉拥挤效应的影响

目的：建立单眼视的模拟方法及周边视觉拥挤效应的测量方法，并利用该方法评估模拟单眼视下的周边视觉拥挤效应是否较正常情况更严重。方法：实验研究。于2015 年3-11 月期间选取温州医科大学眼视光学院在校健康学生和教师20例。正常对照时，双眼均给予清晰的视标（模糊度数为0 D）；模拟单眼视时，左眼给予清晰的视标，右眼给予模糊的视标（模糊度数分别为0.75、1.50、2.50、3.50 D，顺序随机）。视觉拥挤效应的目标视标的偏心度（Ecc）为2.5°、5.0°、7.5°（顺序随机），阈值测量方法为心理物理学的阶梯法。通过比较模拟单眼视状态与正常对照状态的视觉拥挤效应的特征和差异，评估模拟单眼视对视觉拥挤效应的影响。不同模糊度数及不同Ecc时视觉拥挤效应的比较采用双因素重复测量方差分析，组间两两比较采用Bonferroni矫正过的t检验。结果：视觉拥挤效应显著依赖于模糊度数（F=13.37，P<0.001）和Ecc（F=296.90，P<0.001）。模糊度数与Ecc的交互作用显著（F=4.03，P<0.001）。当Ecc分别为7.5°、5.0°时，不同模糊度数下测得的视觉拥挤效应差异均有统计学意义（F=8.59，P<0.001；F=3.74，P=0.01），模糊度数越大，视觉拥挤效应越重。当Ecc为2.5°时，不同模糊度数下测得的视觉拥挤效应差异均无统计学意义（F=1.13，P=0.34）。结论：相比于正常对照情况，模拟单眼视下的视觉拥挤效应加重，并且与模糊眼的模糊度数及目标视标的Ecc相关。     

Conductive keratoplasty for symptomatic presbyopia following monofocal intraocular lens implantation

Background: To evaluate the visual outcomes of conductive keratoplasty for relief of symptomatic presbyopia of pseudophakia with monofocal intraocular lens implantation. Design: It was a prospective clinical study and set in Eye Center, Second Affiliated Hospital, Zhejiang University. Participants: This study comprised 27 eyes from 27 patients with presbyopia symptom. Methods: The patients received conductive keratoplasty via monovision approach after monofocal intraocular lens implantation and were followed up at 1 week and 1, 3, 6 and 12 months postoperatively. Main Outcome Measures: The main outcomes including uncorrected near visual acuity, uncorrected distance visual acuity, best spectacle‐corrected visual acuity, manifest refraction spherical equivalent, keratometric astigmatism, contrast and glare sensitivity, spherical aberration and pseudoaccommodation were evaluated. Results: Twelve months after conductive keratoplasty, the binocular uncorrected near visual acuity was significantly improved from logMAR 0.88 ± 0.16 preoperatively to logMAR 0.30 ± 0.13 (P < 0.05); the binocular uncorrected distance visual acuity and best spectacle‐corrected visual acuity remained unchanged; manifest refraction spherical equivalent was significantly reduced from 0.01 ± 0.68 D preoperatively to ?1.68 ± 0.39 D (P < 0.05); spherical aberration was increased from 0.266 ± 0.204 µm preoperatively to 0.358 ± 0.277 µm (P < 0.05), and pseudoaccommodation was from 1.38 ± 0.38 D to 1.73 ± 0.61 D (P < 0.05). Conclusions: Conductive keratoplasty is a safe and effective method for relief of symptomatic presbyopia of pseudophakia with monofocal intraocular lens implantation.     

An international survey of contact lens prescribing for presbyopia

Purpose: The aim was to determine world‐wide patterns of fitting contact lenses for the correction of presbyopia. Methods: Up to 1,000 survey forms were sent to contact lens fitters in each of 38 countries between January and March every year over five consecutive years (2005 to 2009). Practitioners were asked to record data relating to the first 10 contact lens fittings or refittings performed after receiving the survey form. Results: Data were received relating to 16,680 presbyopic (age 45 years or older) and 84,202 pre‐presbyopic (15 to 44 years) contact lens wearers. Females are over‐represented in presbyopic versus pre‐presbyopic groups, possibly reflecting a stronger desire for the cosmetic benefits of contact lenses among older women. The extent to which multifocal and monovision lenses are prescribed for presbyopes varies considerably among nations, ranging from 79 per cent of all soft lenses in Portugal to zero in Singapore. There appears to be significant under‐prescribing of contact lenses for the correction of presbyopia, although for those who do receive such corrections, three times more multifocal lenses are fitted compared with monovision fittings. Presbyopic corrections are most frequently prescribed for full‐time wear and monthly replacement. Conclusions: Despite apparent improvements in multifocal design and an increase in available multifocal options in recent years, practitioners are still under‐prescribing with respect to the provision of appropriate contact lenses for the correction of presbyopia. Training of contact lens practitioners in presbyopic contact lens fitting should be accelerated and clinical and laboratory research in this field should be intensified to enhance the prospects of meeting the needs of presbyopic contact lens wearers more fully.     

The Quest for Spectacle Independence: A Comparison of Multifocal Intraocular Lens Implants and Pseudophakic Monovision for Patients with Presbyopia

ABSTRACT

We performed a literature review comparing multifocal intraocular lens (IOL) implantation with pseudophakic monovision to treat presbyopia. Multifocal IOLs utilize refractive or diffractive principles to treat both distance and near vision, with a single lens implant. Monovision uses traditional monofocal lens implants to treat the dominant eye for emmotropia, and the non-dominant eye for myopia. This planned anisometropia is designed to enhance intermediate or near vision. Generally, distance vision was similar with both types of lens implantation, near vision was better with multifocal IOLs, and intermediate vision appeared to be better in the monovision group. For patients requiring cataract surgery, both multifocal IOLs and monovision appear to address presbyopia with a high level of patient satisfaction. More patients reported complete spectacle independence with multifocal IOLs, but more glare and halos were reported by multifocal IOL patients as well.