Knauer Christine, Pfeiffer Norbert
Universitäts-Augenklinik, Langenbeckstrasse 1, Gebäude 102, 55131 Mainz, Germany.
Graefes Arch Clin Exp Ophthalmol. 2008 Apr;246(4):477-82. doi: 10.1007/s00417-007-0668-4. Epub 2007 Dec 11.
The value of vision is assumed to be very high. To verify this assumption and to assign resources in medical care accordingly, it is necessary to quantify the value of vision. Although the value of vision is difficult to measure, visual quality of life can be quantified as a surrogate criterion. The measured value gains even more relevance if a comparison can be made between visual quality of life and systemic diseases. Multidisciplinary comparisons are only possible by using utility analysis. Two established methods to measure utility values are the standard gamble method and the time trade-off method. The purpose of this review is to find ophthalmologic utility values, and utility values affected by systemic diseases that correlate to the ophthalmologic ones.
A literature search was conducted through PubMed of the National Library of Medicine ( http://www.ncbi.nlm.nih.gov ; date: 06.02.2006). The search terms were: "time trade-off / standard gamble" [text word] and "eye / vision / visual" [text word]; results 24. A report was classified as relevant if visually impaired persons were tested by the time trade-off method or the standard gamble method, or if information was provided on the reliability and validity of these measurements in a group of visually impaired persons. Additional searches were done to find associated publications. A total of 42 publications were found to be of interest.
Results showed that patients, with 20/30-20/50 visual acuity would be willing to pay 19% of their lifetime to get back normal visual acuity. Patients with 20/200-20/400 visual acuity would give up 48% of their lifetime, and blind people would give 60% of their lifetime to regain normal visual acuity. Comparable utility values are seen in patients with AIDS (21%), patients after a stroke who are unable to walk and wash themselves without assistance (46%), and bedridden and incontinent patients following a stroke (66%).
Patients attach great value to vision. The time trade-off method appears to be an appropriate tool to quantify visual quality of life, and one that can be used to compare utility values of different diseases.
视力的价值被认为非常高。为了验证这一假设并据此在医疗保健中分配资源，有必要对视力的价值进行量化。尽管视力的价值难以衡量，但生活视觉质量可以作为替代标准进行量化。如果能够在生活视觉质量和全身性疾病之间进行比较，那么所测得的值就更具相关性。只有通过效用分析才能进行多学科比较。两种既定的测量效用值的方法是标准博弈法和时间权衡法。本综述的目的是找出眼科效用值以及受全身性疾病影响且与眼科效用值相关的效用值。
结果显示，视力为20/30 - 20/50的患者愿意支付其一生19%的时间来恢复正常视力。视力为20/200 - 20/400的患者会放弃其一生48%的时间，而盲人会放弃一生60%的时间来恢复正常视力。在艾滋病患者（21%）、中风后无法独立行走和洗漱的患者（46%）以及中风后卧床且大小便失禁的患者（66%）中也观察到了类似的效用值。
患者非常重视视力。时间权衡法似乎是量化生活视觉质量的合适工具，并且可用于比较不同疾病的效用值
