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刘莛 《中华实验眼科杂志》2017,(6):567-571
老视是一种年龄相关的生理性老化现象.老视手术治疗已逐渐成为屈光手术最终需要面对的挑战.目前,其手术矫治包括眼外(施于角膜或巩膜)和眼内(晶状体置换或施于晶状体本身)两大策略,如角膜准分子激光手术、热传导成形术、飞秒激光基质内环形切开术、角膜植入物手术、各种多焦人工晶状体植入术、可调节人工晶状体植入术、晶状体软化术、巩膜扩张术等.各种手术方法均存在自身的优势和不足.本文就目前现有和近期即将问世的老视治疗方法及其被关注的问题作一综述. 相似文献
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老视是随着年龄增长、调节能力丧失出现视近物困难的一种生理现象,发病机制尚不明确。人口老龄化使老视人口及老视矫正的需求逐渐增多,老视的手术矫正方法正成为眼科医师关注的热点。随着技术和材料的不断发展,出现了多样化的老视矫正手术,包括经角膜老视矫正手术、晶状体老视矫正手术和巩膜老视矫正手术。尽管还没有一种完美的老视矫正手术能真正恢复眼的调节功能,现有的手术已取得一些临床效果。现对老视的角膜手术矫正方法做一综述。 相似文献
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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。 相似文献
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老视是一种随着年龄增长而调节力逐渐下降的自然现象。 目前老视的机制尚未完全阐明,因此多种手术方法用于改善老视眼的调节。其中准分子激光手术成为矫正老视一种重要方法,而且其安全性及有效性不断进步。本文就老视的发生机制、治疗方法以及准分子激光矫正老视的手术方式和切削模式进行综述。 相似文献
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The mechanism of presbyopia 总被引:2,自引:0,他引:2
Accommodation in humans refers to the ability of the lens to change shape in order to bring near objects into focus. Accommodative loss begins during childhood, with symptomatic presbyopia, or presbyopia that affects one's day to day activities, striking during midlife. While symptomatic presbyopia has traditionally been treated with reading glasses or contact lenses, a number of surgical interventions and devices are being actively developed in an attempt to restore at least some level of accommodation. This is occurring at a time when the underlying cause of presbyopia remains unknown, and even the mechanism of accommodation is occasionally debated. While Helmholtz' theory regarding the mechanism of accommodation is generally accepted with regard to broad issues, additional details continue to emerge. Age-related changes in anterior segment structures associated with accommodation have been documented, often through in vitro and/or rhesus monkey studies. A review of these findings suggests that presbyopia develops very differently in humans compared to non-human primates. Focusing on non-invasive in vivo human imaging technologies, including Scheimpflug photography and high-resolution magnetic resonance imaging (MRI), the data suggest that the human uveal tract acts as a unit in response to age-related increasing lens thickness and strongly implicates lifelong lens growth as the causal factor in the development of presbyopia. 相似文献
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Cause and treatment of presbyopia with a method for increasing the amplitude of accommodation. 总被引:12,自引:0,他引:12
R A Schachar 《Annals of ophthalmology》1992,24(12):445-7, 452
To understand the mechanism and cause of accommodation and presbyopia, the sclera in the region of the ciliary body of presbyopic patients was expanded. The amplitude of accommodation was increased in all presbyopic patients. A unique hypothesis of accommodation based on increased zonular tension is presented, which when applied clinically, results in a treatment for presbyopia. 相似文献
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M. H. Edwards L. F. Law C. M. Lee K. M. Leung W. O. Lui 《Ophthalmic & physiological optics》1993,13(2):199-204
Amplitude of accommodation was measured in 121 Hong Kong Chinese subjects between the ages of 11 and 65 years, using the 'push-up' method and the results compared with those previously obtained for Caucasian subjects. The results confirm and quantify clinical experience that Chinese people have lower amplitudes of accommodation than Caucasians. If presbyopia is considered to commence when the amplitude of accommodation declines to less than 5 D, then presbyopia in the Chinese race occurs between the ages of 36 and 40 years. By early in the second decade of life the amplitude of accommodation in the Chinese is already lower than that of Caucasians. This suggests that reduced amplitude of accommodation may he due, at least in part, to factors other than longterm environmental effects. 相似文献
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Krause HK 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2011,108(4):324-330
People in the second half of their lives often require reading glasses. A basic requirement for determining suitable reading glasses is measurement of the patient's accommodation, which describes the change in the eye's optical power caused by the attempt to clearly focus on an object at a certain distance. The maximum accommodation performance of a person already begins to decline from the age of 40 onwards. When it becomes increasingly difficult to adjust to the typical reading distance of 40 cm, one speaks of presbyopia: age-related farsightedness. This contribution describes two appropriate methods for determining the strength of reading glasses: determination of the maximum accommodation performance by measuring the near point distance and determination of the maximum accommodation effort by measuring the relative positive and negative accommodation. Optimal reading glasses enable the patient to focus sharply on something from the working distance that is closer but also on something that is further away. 相似文献