视功能损害眼病患者生存质量量表的研究

目的研究一个适合测量我国视功能损害眼病患者的生存质量量表。方法通过指标筛选，最终选择２０个指标形成生存质量量表。应用该量表测量了５７例单纯视力损害的白内障患者和６０例有不同程度视力及视野损害的青光眼患者，并对该量表进行效度、信度和反应性的评价。结果该量表２０个指标，包括症状、视功能、身体机能、社会活动及精神心理等四个方面。（１）准则关联效度：ｒ＝０．６８６５，Ｐ＝０．０００。（２）重测信度：ｒ＝０．８９５９，Ｐ＝０．０００；克朗巴赫系数：α＝０．９３５８；方差比＝０．０５５１；分半信度：Ｒ＝０．９５５３。（３）反应度：ｔ检验＝５．９５（Ｐ＝０．０００），效应大小统计量为１．５３３。结论该量表具有满意的效度、信度和反应度。可试用于临床试验评价     

The MacDQoL individualized measure of the impact of macular degeneration on quality of life: reliability and responsiveness

PURPOSE: To investigate the MacDQoL test-retest reliability and sensitivity to change in vision over a period of one year in a sample of patients with age-related macular degeneration (AMD). DESIGN: A prospective, observational study. METHOD: Patients with AMD from an ophthalmologist's list (n = 135) completed the MacDQoL questionnaire by telephone interview and underwent a vision assessment on two occasions, one year apart. RESULTS: Among participants whose vision was stable over one year (n = 87), MacDQoL scores at baseline and follow-up were highly correlated (r = 0.95; P < .0001). Twelve of the 22 scale items had intraclass correlations of >.80; only two were correlated <.7. There was no difference between baseline and follow-up scores (P = .85), indicating excellent test-retest reliability. Poorer quality of life (QoL) at follow-up, measured by the MacDQoL present QoL overview item, was associated with deterioration in both the better eye and binocular distance visual acuity [VA] (r = 0.29; P = .001, r = 0.21; P = .016, respectively; n = 135). There was a positive correlation between deterioration in the MacDQoL average weighted impact score and deterioration in both binocular near VA and reading speed (r = 0.20; P = .019, r = 0.18; P = .041, respectively; n = 135). CONCLUSION: The MacDQoL has excellent test-retest reliability. Its sensitivity to change in vision status was demonstrated in correlational analyses. The measure indicates that the negative impact of AMD on QoL increases with increasing severity of visual impairment.     

近视患者的视觉生活质量调查表的初步研究

目的研究一个适合测量我国近视患者的视觉生活质量调查表。方法通过专家及统计学指标筛选,最终选择22个指标形成生活质量量表。应用该量表测量了450例术前及365例LASIK术后1—12个月近视患者,并对该量表进行效度、信度和反应度的评价。结果该量表22个指标,包括视功能及症状、身体机能、社会活动及精神心理等四个方面。（1）内容效度：四个分项与总分的相关系数分别为0．915、0．784、0．628、0．412,P=0．000;区分效度：t=9．737,P=0．000。（2）重测信度：r=0．717,P=0．000;克朗巴赫系数：α=0．863;分半信度：R=0．907。（3）反应度：t=6．943,P=0．000,效应大小统计量ES为0．55。结论该量表具有满意的效度、信度和反应度。可试用于临床试验评价。     

非斜视性双眼视异常学龄儿童生活质量量表研制

目的 初步研制非斜视性双眼视异常学龄儿童的生活质量量表,并评价其效度、信度和反应度。方法 调查研究。根据量表设计原则,经统计学评价,综合眼视光学和公共卫生学专家意见,设计非斜视性双眼视异常学龄儿童生活质量量表（加注拼音）。非斜视性双眼视异常判断标准：眼部不适、酸胀、视物模糊、视觉疲劳、复像或文字跳行重叠等症状明显,根据Morgan正常值,Sheard、Percival准则,综合分析是否为非斜视性双眼视异常并进行疗效评价。调查非斜视性双眼视异常小学生116例,首次调查2周后接受再次调查,其中经治疗训练有效的103例于停止治疗后第3个月随诊时接受第3次调查;选择双眼视功能正常小学生100例作为对照。应用变异系数、相关系数、因子分析、逐步回归分析、逐步判别分析、克朗巴赫系数、重测信度和分半信度来筛选量表的有效条目,评价量表的效度、信度和反应度。结果 该量表20个条目,包括双眼视功能、生活自理能力、活动交往以及精神心理等4个分项,具有良好的结构效度（经因子分析提取的4个公因子与本量表的4个分项一致,累计方差贡献率53.15%,各条目在其所属公因子上的因子载荷值均大于0.50）、内容效度（每个条目得分与所属分项得分的相关系数r均大于0.55;4个分项与总得分的相关系数r分别为0.87、0.48、0.49、0.54）和区分效度[双眼视功能正常与非斜视性双眼视异常小学生得分差异有统计学意义（t=1.97,P<0.01）及异常者经治疗训练前后得分差异有统计学意义（t=1.97,P<0.01）];重测信度r为0.98（P<0.01）,克朗巴赫α系数均达到0.70以上,分半信度Rh为0.78（P<0.01）;效应尺度统计量（ES）为0.53。结论 该量表符合生活质量量表效度、信度、反应度和容易分析的技术要求,可试用于临床研究。     

中文版IND-VFQ-33在白内障人群中的应用与评价

目的研制中文版印度视功能量表（IND-VFQ-CN-33）,评价其在中国白内障人群中的测量特性,并初步分析白内障患者术前生活质量的影响因素。方法横断面调查研究。对IND-VFQ-33量表进行标准的翻译、回译和跨文化调试后,选取在温州医科大学附属眼视光医院确诊的白内障住院患者293例进行调查,其中45例患者用于评估2名调查者信度。通过Cronbach′s α系数分析量表的内部一致性;Pearson相关分析评估评定者间信度;内容效度指数评估内容效度;探索性因子分析评估结构效度,评价量表的适用性、项目区分度及信度、效度。通过独立样本t检验分析不同性别、年龄、文化程度条件下生活质量的差异,并通过单因素方差分析不同双眼远视力情况下生活质量的差异。结果中文版IND-VFQ-CN-33项目区分度好。内部一致性和评定者间信度较高,总表的Cronbach′s α系数为0.93。量表水平内容效度指数为0.84;结构效度的探索性因子分析提取出8个公因子,累积方差贡献率为67.62%。男性患者的心理评估子表得分高（t=-3.27,P＜0.05）,文盲患者的视功能子表（t=-3.03,P＜0.05）和心理评估子表（t=-3.45,P＜0.05）得分高。单因素方差分析发现不同双眼远视力组间差异均有统计学意义（F=3.66~24.37,P＜0.05）。结论IND-VFQ-CN-33在中国白内障术前人群中适用性好,具有较优的测量特性,可用于中国白内障术前人群的生活质量评估研究。白内障男性患者的心理方面生活质量下降较女性更加显著,文盲患者的视功能和心理方面生活质量下降较非文盲患者更加显著。     

Quality of life in glaucoma and its relationship with visual function

PURPOSE: The aims of this study were (a) to explore patients self-reported visual disability resulting from glaucoma by means of a questionnaire developed for this purpose; (b) identify activities strongly associated with a measure of visual field loss, (c) to quantify different psychophysical aspects of visual function; (d) to assess the relationship between objective measures of visual function and patients' perception of their vision-related quality of life. PATIENTS AND METHODS :Three groups of glaucoma patients (n = 47) with mild (n = 18), moderate (n = 19), and severe visual field loss (n = 10) and a group of normal controls (n = 19) underwent a comprehensive clinical examination, completed a questionnaire and, on a separate visit, performed a number of psychophysical tests of visual function. MAIN OUTCOME MEASURES: Questionnaire responses (vision-related quality of life, general health and psychosocial variables), visual acuity, visual fields, Esterman binocular disability scores, contrast sensitivity, critical flicker frequency, color vision, dark adaptation, glare disability (brightness acuity), and stereoacuity scores were measured. RESULTS: Fifteen of the 50 questions were noted to have a strong significant relationship with a measure of visual field loss and were included in a new questionnaire scale, the Glaucoma Quality of Life - 15 (GQL-15). The scale validity showed a significant correlation with perimetric mean deviation (MD) values (r = -0.6; P < 0.0001), the reliability of the scale was high (Cronbach alpha = 0.95), and test-retest reliability of the questionnaire was strong (r = 0.87). An overall statistically significant decrease in performance-related quality of life was noted between normal subjects and all groups of glaucoma patients. A significant relationship was found between the scale questionnaire summary performance measure and a number of psychophysical tests: Pelli-Robson contrast sensitivity (r = -0.45, P < 0.001), glare disability (r = -0.41, P < 0.001), Esterman binocular visual field test (r = -0.39, P < 0.001), dark adaptation (r = 0.34, P = 0.007), and stereopsis (r = 0.26, P = 0.04). CONCLUSION: Perceived visual disability relating to certain tasks (particularly involving dark adaptation and disability glare, activities demanding functional peripheral vision such us tripping over and bumping into objects and outdoor mobility tasks) was significantly associated with the severity of binocular visual field loss. As a result, a new glaucoma-specific questionnaire scale with good performance characteristics is presented in this study. The difficulties encountered by patients in everyday life (as measured with the questionnaire) were also mirrored in their performance on a number of psychophysical tests, especially contrast sensitivity, glare disability, Esterman binocular visual field test, and dark adaptation.     

Assessment of vision-related function in patients with age-related macular degeneration

OBJECTIVE: To investigate the validity of the visual function index (VF-14) in assessing visual function in patients with age-related macular degeneration (AMD). DESIGN: Prospective noncomparative observational case series. PARTICIPANTS: One hundred fifty-nine consecutive patients attending a sole practitioner's academic retina-only clinic from May 1998 through August 1998 and from May 1999 through August 1999. MAIN OUTCOME MEASURES: Correlations were calculated between the VF-14 scores and the medical outcomes study 36-item short form (SF-36), weighted comorbidity scale, visual acuity and clinical AMD severity (stage), and vision self-assessment scales. Documentation of the severity of macular degeneration was performed by a sole examiner. RESULTS: There was a moderately strong correlation between visual acuity and trouble with vision (r = 0.51), satisfaction with vision (r = -0.50), and overall quality of vision (r = -0.56). A strong correlation was noted between VF-14 score and patients' self-rating of amount of trouble with vision (r = -0.67), satisfaction with vision (r = 0.62), and overall quality of vision (r = 0.67). In comparison, correlations between SF-36 score and patients' self-rating of amount of trouble with vision, satisfaction with vision, and overall quality of vision ranged from r = 0.37 to r = -0.40. Linear regression analysis for the overall study population indicated that AMD severity was not an independently significant predictor of VF-14 score after adjusting for visual acuity. However, among patients with 20/20 vision in the better eye, AMD severity was an independently significant predictor of VF-14 score after adjusting for visual acuity in the worse eye. CONCLUSIONS: The VF-14 exhibits a considerable degree of validity as a measure of functional impairment in patients with AMD. Age-related macular degeneration severity was an independently significant predictor of VF-14 score in the group of patients with 20/20 vision in the better eye, but this did not hold true for the overall study population. Age-related macular degeneration is associated with substantial impairment in reported visual function.     

青光眼与生存质量的关系

目的:了解青光眼患者视功能损害与生存质量的关系,探讨影响青光眼患者生存质量的主要因素。方法:应用视功能损害眼病生存质量量表测量60例有不同程度视功能损害的慢性闭角型青光眼及开角型青光眼患者的生存质量情况。结果:青光眼患者的视功能改变与生存质量之间存在相关关系(r=0.66,P=0.000),影响青光眼患者生存质量的主要因素是视功能损害,性别及职业。结论:青光眼患者视功能损害降低病人的生存质量,生存质量测量为青光眼筛检及治疗方案选择提供新的指标。眼科学报 1996;12:183～187。     

SQOL-DV1对甲状腺相关眼病患者生活质量的评估

目的:对视功能损害眼病患者生存质量量表(The quality oflife scale which measures the quality of life for Chinese patients with visual impairment,SQOL-DV1)应用于甲状腺相关眼病(thyroid associated ophthalmopathy,TAO)患者生活质量评价进行效度、信度和反应度检验。方法:应用SQOL-DV1量表对39例TAO患者和31例正常对照组进行调查。分析该量表能否准确有效评估TAO患者的生活质量。结果:效度分析:(1)内容效度检验各个分项得分之间的相关系数0.62～0.80(P=0.00),各个分项得分与量表总得分的相关系数0.88～0.89(P=0.00)。(2)区分效度检验TAO患者组在症状与视功能、身体机能、社会活动、精神心理各分项得分及量表总分上均低于正常对照组(P=0.00),治疗后TAO患者量表各分项得分及总得分提高(P<0.05)。信度分析:(1)重测信度。量表重复测量相关系数达到0.913(P=0.00)。(2)克朗巴赫系数为0.944。反应度分析:效应大小统计量(ES)为0.88。结论:SQOL-DV1量表是评估TAO患者生活质量的一种有效、可信的工具,可用于临床上TAO患者生活质量的测量和相关研究。     

Visual function and change in quality of life after bilateral refractive lens exchange with the ReSTOR multifocal intraocular lens

PURPOSE: To evaluate vision and quality of life and explore the correlation between vision and change of quality of life after bilateral refractive lens exchange of the Acrysof SA60D3 ReSTOR multifocal intraocular lens (IOL) for correction of ametropia in presbyopic populations. METHODS: Pre- and postoperatively, the National Eye Institute Refractive Error Quality of Life Instrument (NEI-RQL) was self-administered by 30 consecutive refractive lens exchange patients, including 19 myopes and 11 hyperopes. The change of NEI-RQL scores was determined for each subscale covering a specific aspect of quality of life. Refraction, visual acuity, and contrast sensitivity function were evaluated 3 and 6 months postoperatively. RESULTS: Postoperatively, all patients achieved binocular uncorrected distance and near visual acuity of 20/30 or better. Photopic contrast sensitivity function decreased significantly at high spatial frequencies (P < .05). Overall scores of expectations, activity limitations, dependence on correction, appearance, and satisfaction were significantly higher postoperatively (P < .05). Greater improvement in near vision and dependence on correction was achieved in hyperopes. However, glare scores were significantly lower postoperatively (P < .001). Lower preoperative uncorrected near visual acuity was associated with higher scores for dependence on correction in myopes (r = 0.51, P = .027), and overall patient satisfaction correlated significantly with postoperative uncorrected distance visual acuity (r = -0.44, P = .015). CONCLUSIONS: Refractive lens exchange with the ReSTOR IOL in presbyopic patients provided good visual function and better patient satisfaction compared with preoperative corrections. Improvement in vision-related quality of life was most evident in hyperopes. A slight reduction in contrast sensitivity function appears to have no influence on quality of life.     

双眼先天性白内障儿童生活质量量表的制订及评价

目的制订8～15岁双眼先天性白内障儿童生活质量量表,评价量表的效度、信度以及反应度。方法根据儿童生活质量的定义设计,涵盖与视功能损害有关的重要指标,编制23个条目的双眼先天性白内障儿童生活质量量表。应用该量表对8～15岁的18例正常视力儿童和76例双眼先天性白内障儿童进行了量表调查。应用离散程度法、相关系数法、因子分析法、区分度分析法、克朗巴赫系数法和重测信度法来筛选量表有效条目,并评价筛选后量表的效度、信度以及反应度。结果条目5、7和21经筛选后删除,形成20个条目的量表。每个条目和每个分项的内容效度相关系数均大于0．6（P〈0．05）。正常儿童和白内障儿童、白内障儿童术前和术后总得分间的差异均有统计学意义（P=0．000）。重测信度的相关系数为0．895（P=0．000）。本量表4个分项的克朗巴赫a信度系数值分别为0．822、0．922、0．797和0．794。效应尺度统计量为1．141。结论经筛选后的20个条目的量表符合生活质量量表效度、信度以及反应度的技术要求,可以应用于8～15岁的双眼先天性白内障儿童生活质量的临床研究。     

Validity and reliability of the Cataract TyPE Spec: an instrument for measuring outcomes of cataract extraction

PURPOSE: To design and validate a survey instrument that measures vision-related functional status, which is appropriate for self-administration in a clinical practice and mail survey setting. DESIGN: Observational, validation study in sequential patients. METHODS: A prototype visual function instrument (the Cataract TyPE Spec) was developed based on focus group input and then validated in an outcomes study conducted among 1,823 patients who underwent cataract extraction performed by 22 surgeons at six centers in the United States. Reliability was determined by calculating Cronbach alpha for different types of administration (self-administration at the site of care and mailed survey) and across race and gender. Criterion validity was determined by correlating scores on the TyPE Spec with baseline measures and changes in visual acuity, overall rating of vision, and general quality of life. RESULTS: The instrument was internally valid (Chronbach alpha = 0.94), both on self-administration in the patient care setting and upon mailed survey administration and across patient race and gender. The TyPE Spec score was highly correlated with overall rating of vision (r =.54, P <.0001) and moderately correlated with Snellen acuity (r =.32, P <.0001), rating of vision in the better eye (r =.42, P <.0001), and quality of life, as measured by the physical component summary score of the SF-36 (r =.27, P <.001). Change in TyPE Spec similarly correlated with change in rating of vision overall, change in best-corrected Snellen acuity, and change in rating of vision in the operated eye. CONCLUSIONS: The cataract TyPE Spec instrument was found to be equally valid and internally consistent when administered in the patient care setting and by mail survey.     

屈光矫正者生命质量量表在中国的应用及评价

目的 研制屈光矫正者生命质量量表（QIRC）中文版并评价其信度和效度。方法 通过对原量表的翻译、回译和语言调试等形成中文版的QIRC,对58例屈光手术术前和47例术后患者进行生命质量测量,评价其信度和效度。结果 该量表包括症状、视功能与身体机能、社会活动及精神心理4个模块,共20项指标。量表的各模块与自评满意程度的重测相关系数均在0.70以上,整个量表的重测信度为r=0.987;各模块内部一致性信度α为0.518～0.764;折半信度为R=0.695。采用因子分析法,共提取6个因子,累计方差贡献率为59.93%,基本证实了其结构效度;该量表能够区分术前和术后患者生命质量之间的差异。结论 QIRC中文版具有较好的信度和效度,可用于临床屈光矫正者的生命质量评价。     

Evaluation of quality of life characteristics and grade of legal visual impairment

PURPOSE: To evaluate the possible correlation between quality of life (QOL) characteristics and grades of legal visual impairment. MATERIALS AND METHODS: Quality of life characteristics associated with various causes of visual loss were investigated in 237 Japanese patients in the low-vision care clinic at Tokyo University Hospital, who had been issued the official ID and handbook for the physically handicapped. The main causes of vision loss were glaucoma (87 patients), macular degeneration (35) and diabetic retinopathy (34). Using a previously developed questionnaire, we assessed the correlation between the disability index (DI) as a quality of life characteristic, and the grade of legal visual impairment. RESULTS: Total DI was 1.24 +/- 0.43, showing a very significant correlation with Handicapped Handbook grades (r = -0.44, p < .0001). The correlation coefficients were -0.63 (p < 0.0001) for diabetic retinopathy, -0.50 (p = 0.002) for macular degeneration, and -0.16 (p = 0.14) for glaucoma patients. CONCLUSION: The needs of low-vision patients correlate with the grade of legal visual impairment and it is important to understand that the needs of low vision patients differ for each disease.     

国人白内障视功能相关生存质量简表的研制及其测量特性评价

目的 研制国人白内障视功能相关生存质量简表Catquest-9SF并评价其在中国白内障人群中的适用性、项目区分度及信、效度,为中国白内障人群的视功能相关生存质量评价提供科学、简便的工具,并初步分析白内障术前患者生存质量的影响因素。方法 横断面调查研究。对原Catquest-9SF量表进行翻译、回译和跨文化调试,选取在温州医科大学附属眼视光医院确诊的白内障住院患者150例行量表调查,其中50例患者由2名调查者先后进行调查。对数据进行内部一致性、评定者间信度、内容效度和结构效度等分析,评价量表的适用性、项目区分度及信、效度,并分析得分的相关因素。结果 国人白内障视功能相关生存质量简表Catquest-9SF简短易行,项目区分度好;总表的Cronbach′s α系数为0.90;评定者间信度的Bland-Altman 95%一致性界限为-2.1~2.0,Pearson相关性分析表明评定者间信度高度相关（r=0.988,P＜0.01）;量表水平内容效度指数为0.98;结构效度的探索性因子分析提取出1个公因子,解释方差百分比为55.89%,累积方差贡献率为55.89%。量表得分和视力（r=0.43,P＜0.01）及年龄（r=-0.22,P<0.01）的相关性显著,不同性别的患者得分差异有统计学意义（t=-2.30,P<0.05）,不同文化程度和第一眼/第二眼手术的患者得分差异无统计学意义。结论 国人Catquest-9SF量表在中国南方地区适用性好,且具有良好的信、效度,是评价中国南方地区白内障人群视功能相关生存质量简单而有效的可行工具。     

Self-reported importance and difficulty of driving in a low-vision clinic population

PURPOSE: To validate estimates of self-perceived driving ability from difficulty ratings of driving tasks and to determine the association of the importance and difficulty of driving with the magnitude of visual impairments. METHODS: A consecutive series of 851 patients at a low-vision clinic rated the importance of driving on a four-point scale. Those who gave nonzero importance ratings then rated driving difficulty on a five-point scale. Those who gave nonzero difficulty ratings then rated the difficulty of each of 21 driving tasks on a five-point scale. Visual acuity was measured with the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart, and contrast sensitivity was measured with the Pelli-Robson chart. Rasch analysis was used to test the validity and reliability of self-perceived driving ability estimates from difficulty ratings of tasks. RESULTS: Patients who rated driving as not important (41%) had worse visual acuity (logMAR = 0.88) and worse contrast sensitivity (log CS = 0.83) than did those who rated driving as extremely important (55%; logMAR = 0.62; log CS =1.03; multivariate analysis of variance [MANOVA]; P = 0.003). Self-perceived driving ability correlated negatively with the overall rating of driving difficulty (r = -0.69; P < 0.001) and with logMAR (r = -0.28; P < 0.001), and correlated positively with log CS (r = 0.35; P < 0.001). The most difficult driving tasks were navigating in parking ramps, parking in the correct space, seeing lane markings, and reading signs. The least-difficult driving tasks were seeing traffic and reading the speedometer. Rasch analysis confirmed instrument validity and reliability. CONCLUSIONS: Low-vision patients appeared to devalue the goal of driving when visual impairments were more severe. Valid measures of self-perceived driving ability can be estimated from difficulty ratings of specific driving tasks.     

The impact of cataract surgery on cognitive impairment and depressive mental status in elderly patients

PURPOSE: To evaluate the influence of cataract surgery on cognitive function and depressive mental status of elderly patients. DESIGN: Prospective, interventional case series. METHODS: The 25-Item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25), Mini-Mental State Examination (MMSE), and Beck Depression Inventory (BDI) are the measures designed to assess vision-related quality of life (QOL), cognitive impairment, and depressive mental status, respectively. These tests were performed before and two months after surgery in 102 patients undergoing phacoemulsification and intraocular lens implantation for bilateral cataract. RESULTS: The change in best-corrected visual acuity by surgery significantly correlated with the change in NEI VFQ-25 score (Pearson correlation, r = -0.310; P = .031). The change in NEI VFQ-25 score by surgery significantly correlated with the change in MMSE score (r = 0.306; P = .035) and the change in BDI score (r = -0.414; P < .001). The change in MMSE score showed significant correlation with the change in BDI score (r = -0.434; P < .001). CONCLUSIONS: Vision-related QOL, cognitive impairment, and depressive mental status are all strongly related with each other. Cataract surgery significantly improved vision-related QOL in elderly patients, and cognitive impairment and depressive mental status also improved in parallel with improvement in vision-related QOL.     

Implementation methods for vision related quality of life questionnaires

AIM: To determine the most reliable and consistent method and time interval over which to implement a vision impairment quality of life assessment tool. METHODS: 117 patients with low vision aged 9-101 years were assigned into three age, sex, and visual function matched groups (n = 39 in each) to answer the Low Vision Quality of Life (LVQOL) questionnaire by post, telephone, or in person. The LVQOL questionnaire was completed on four occasions, each separated by four weeks. RESULTS: Postal implementation was the most cost effective method, showed the highest internal consistency of LVQOL items, but resulted in a lower apparent quality of life score than either telephone or in-person interviews (p<0.001). There was no difference in test-retest reliability between the three methods of implementation (p = 0.12). The profile of LVQOL scores showed a trend towards reduced quality of life scores 3 months after the baseline measures, although this was not significant. CONCLUSION: Posting may be the method of choice for clinical measurement of vision related quality of life. Patients with greater visual impairment were no less likely to complete a questionnaire when implemented by post and there was no apparent bias from other people assisting them. The quality of life measure can occur at any time up to 2 months after low vision rehabilitation for the progressive nature of conditions causing low vision not to cause a decreased baseline score. The LVQOL was shown to be a highly internally consistent and reliable method for measuring quality of life in the visually impaired.     

Utility-based estimates of the relative morbidity of visual impairment and angina

PURPOSE. To quantify and compare the reduction in quality of life due to visual impairment and angina using patient preferences (utilities). METHODS. Using a standard time tradeoff method, we obtained utilities for current vision, monocular and binocular blindness, current angina, and moderate angina in 60 patients with both vision problems and angina pectoris who sought care at the National Eye Institute (NEI), National Naval Medical Center, or Barnes-Jewish Hospital. Patients were characterized clinically based on visual acuity and the Duke Activity Status Index (DASI). Patients also completed a seven-item version of the NEI Visual Functioning Questionnaire and the SF-36 Health Survey Questionnaire. RESULTS. Patients had a median visual acuity of 20/100 in the worst eye, 20/40 in the better eye, and a median DASI of 24.2 (0 = severe functional limitations due to anginal symptoms, 58.2 = no limitations). There was substantial variation in utilities among patients. The average utility for current vision (relative to ideal vision [= 1.0] and death [= 0.0]) was 0.82; the average utility for current angina (relative to no angina symptoms [= 1.0] and death [ = 0.0]) was 0.89. Among 26 patients with both visual impairment and recent anginal symptoms, the decrement in utility (on a scale ranging from ideal health [= 1.0] to death [= 0.0]) imposed by current visual impairment was greater than that imposed by current angina symptoms (0.146 versus 0.072, p=0.08, Wilcoxon signed rank test). The decrement in utility associated with binocular blindness was greater than the decrement associated with the symptoms of moderate angina (0.477 versus 0.039, p &lt; 0.0001). CONCLUSIONS. Clinical status is not a surrogate for patient preferences regarding vision impairment or angina. There is substantial variation in utilities within the study population for both experienced and theoretical impairment states which is not explained by variations in clinical status. Some states of visual impairment may pose a greater quality of life burden than anginal symptoms. Because patient preferences for vision vary greatly, individual assessment is warranted for consideration in therapeutic decision making.