Psychometric properties of the Veterans Affairs Low-Vision Visual Functioning Questionnaire

PURPOSE: To describe psychometric properties of a self-report questionnaire, the Veterans Affairs (VA) Low-Vision Visual Functioning Questionnaire (LV VFQ-48), which was designed to measure the difficulty visually impaired persons have performing daily activities and to evaluate low-vision outcomes. METHODS: The VA LV VFQ-48 was administered by telephone interview to subjects with visual acuity ranging from near normal to total blindness at five sites in the VA and private sector. Rasch analysis with the Andrich rating scale model was applied to difficulty ratings from 367 subjects, to evaluate measurement properties of the instrument. RESULTS: High intercenter correlations for item measure estimates (intraclass correlation coefficient [ICC]=0.97) justified pooling the data from these sites. The person measure fit statistics (mean square residuals) confirm that the data fit the assumptions of the model. The item measure fit statistics indicate that responses to 19% of the items were confounded by factors other than visual ability. The separation reliabilities for pooled data (0.94 for persons and 0.98 for items) demonstrate that the estimated measures discriminate persons and items well along the visual ability dimension. ICCs for test-retest data (0.98 for items and 0.84 for persons) confirm temporal stability. Subjects used the rating categories in the same way at all five centers. Ratings of slight and moderate difficulty were used interchangeably, suggesting that the instrument could be modified to a 4-point scale including not difficult, slightly/moderately difficult, extremely difficult, and impossible. Fifty additional subjects were administered the questionnaire with a 4-point scale to confirm that the scale was used in the same way when there were four rather than five difficulty ratings. CONCLUSIONS: The VA LV VFQ-48 is valid and reliable and has the range and precision necessary to measure visual ability of low-vision patients with moderate to severe vision loss across diverse clinical settings.     

Using the VA LV VFQ-48 and LV VFQ-20 in low vision rehabilitation.

PURPOSE: This study was conducted to demonstrate use of a simple scoring algorithm for the 48-item Veterans Affairs Low Vision Visual Functioning Questionnaire (VA LV VFQ-48) that approximates the measure of persons' visual ability that would be calculated with Rasch analysis and to provide a short form version of the questionnaire for clinical practice and outcomes research. METHODS: Items were eliminated from the VA LV VFQ-48 to reduce redundancy and shorten the instrument. The approximation of persons' visual ability calculated with the scoring algorithm for vision function questionnaires developed by Massof was compared with the person measure estimated from Rasch analysis for a sample of 126 subjects entering a low vision rehabilitation program. RESULTS: The approximation captures 98% of the variability in the Rasch measure estimate of persons' visual ability and 97% of the variability in the change score estimate. The relationship does not hold in circumstances where patients with high visual ability find most items to be easy. A 20-item short form of the instrument was constructed for use in low vision service delivery. CONCLUSIONS: The scoring algorithm can be used with the VA LV VFQ-48 or short form versions of the questionnaire. Clinicians can use the algorithm to score the VA LV VFQ from examination of individual patients or as an outcome measure for their low vision rehabilitation programs. Research investigators can use the scoring algorithm with small samples when Rasch analysis is not reliable or in studies where Rasch analysis is not practical. Rasch analysis is still recommended for research studies that require more accurate assessments.     

Measuring low-vision rehabilitation outcomes with the NEI VFQ-25

PURPOSE: To evaluate the sensitivity of the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) to change in visual abilities after low-vision rehabilitation in two different Veterans Administration (VA) low-vision programs METHODS: Seventy-seven legally blind veterans from the Blind Rehabilitation Center (BRC) at Hines VA Hospital and 51 partially sighted veterans from the Visual Impairment Center to Optimize Remaining Sight (VICTORS) program at the Chicago Health Care Network, West Side Division, were administered the NEI VFQ-25 plus supplement in interview format at admission and discharge. Instructions for administration were modified to have study participants answer all the questions as if they were wearing glasses or contact lenses or were using low-vision devices. Interval measures of person ability and item difficulty were estimated from the patients' responses to 34 of the 39 items on the VFQ-25 plus supplement before and after rehabilitation, by the polytomous rating scale measurement model of Wright and Masters. RESULTS: In VICTORS patients, item order by difficulty before rehabilitation agreed with item order for BRC patients. Visual ability scales are used similarly by different patients with different degrees of low vision. Based on prerehabilitation person measure distributions, VICTORS patients were less disabled, as would be predicted by visual acuity, than were BRC patients. After rehabilitation, estimated item difficulty for 4 of the 34 items decreased significantly in both BRC and VICTORS patients. CONCLUSIONS: The present study demonstrates that the NEI VFQ-25 plus supplement can be used to measure the effects of low-vision rehabilitation; however, only 7 of the 34 items tested are sensitive to change after rehabilitation. Targeted activities, such as reading ordinary print, small print, and street signs are easier to perform for graduates of both programs after rehabilitation. The patients' visual ability also shows improvement in both BRC and VICTORS. Improvement in visual ability is independent of change in difficulty of targeted items. Although this was not a controlled clinical trial, the decrease in difficulty of targeted items may reflect the use of low-vision aids and training to make tasks easier. The change in visual ability may reflect positive outcomes of rehabilitation or may be the consequence of patients' overestimates of their functional ability at the time of discharge.     

Application of stochastic measurement models to visual function rating scale questionnaires

PURPOSE: To test hypotheses that low vision patient responses to visual function rating scale questionnaires conform to an additive conjoint structure and that the Likert score is a sufficient statistic for the latent patient trait; to compare results for two competing stochastic measurement models; and to determine if different questionnaires measure the same construct in low vision patients. METHODS: Visual function rating scale questionnaires were administered to 284 low vision subjects by telephone. Each subject was administered two of four questionnaires: ADVS, NEI VFQ-25 plus supplement, expanded VAQ, and VF-14. RESULTS: Data were analyzed with the Muraki item response model and the Andrich measurement model. The estimates of latent person, item, and response threshold measures from the two models are linearly related. The Muraki model produced a better overall fit to the item response data, the Andrich model produced a better fit to the average ratings for each person and item. Fit statistics for the Andrich model were proportional to the item-dependent discrimination parameter in the Muraki model. The ADVS was the most accurate measure and the NEI VFQ was the least. Reliability was similar for all four instruments. Person measures for each pair of instruments were linearly related indicating that all four instruments measured the same construct. The person measure estimate from the Andrich model is monotonic with the average rating. That relationship suggests a transformation of the Likert score that can correct the floor and ceiling effects in rating scale data. CONCLUSIONS: Patient responses to all four questionnaires conform to varying degrees to an additive conjoint structure. The Likert score is a sufficient statistic for the ADVS and the VAQ, but not for the NEI VFQ or VF-14. All four instruments measure the same construct in the low vision population, but they differ in measurement accuracy and precision.     

Vision-specific health-related quality of life in age-related maculopathy patients presenting for low vision services

Few studies have examined the effectiveness of low vision rehabilitation for age-related maculopathy (ARM) patients and its impact on vision-specific health-related quality of life (HRQoL). However, before a multi-site clinical trial can be conducted, appropriate outcome measures need to be identified for ARM patients who seek out low vision rehabilitation, including a vision-specific HRQoL instrument. The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was developed to assess vision-specific HRQoL for low vision patients, including those with ARM. This study examines the performance of the NEI VFQ-25 among ARM patients who seek out low vision services and examines its relationship with visual acuity and self-reported use of low vision aids. One hundred and twenty-seven patients were recruited from a University-affiliated low vision clinic. During two telephone interviews, subjects completed the NEI VFQ-25 and a short cognitive test and provided information on general health and use of low vision aids. Additional information on visual acuity and eye health were collected from the medical record. Our results indicate that ARM patients who seek out low vision services report significant impairment in their vision-specific HRQoL. Their NEI VFQ-25 scores were lower compared to other ARM and low vision rehabilitation samples previously studied. The VFQ subscales with the largest deficits were near and distance visual acuities and psychosocial issues (near vision, distance vision, role difficulties, dependency, social functioning, mental health). These subscale scores were lower for those with greater visual acuity impairment. The VFQ subscale scores most impacted by the disease had wide variability and were higher for those who used low vision aids, suggesting that the NEI VFQ-25 is suitable for measuring further decline and treatment-related improvements. Thus, it should be strongly considered for a multi-site clinical trial on the effectiveness of low vision rehabilitation.     

Vision-specific health-related quality of life in age-related maculopathy patients presenting for low vision services

Few studies have examined the effectiveness of low vision rehabilitation for age-related maculopathy (ARM) patients and its impact on vision-specific health-related quality of life (HRQoL). However, before a multi-site clinical trial can be conducted, appropriate outcome measures need to be identified for ARM patients who seek out low vision rehabilitation, including a vision-specific HR QoL instrument. The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was developed to assess vision-specific HRQoL for low vision patients, including those with ARM. This study examines the performance of the NEI VFQ-25 among ARM patients who seek out low vision services and examines its relationship with visual acuity and self-reported use of low vision aids. One hundred and twenty-seven patients were recruited from a University-affiliated low vision clinic. During two telephone interviews, subjects completed the NEI VFQ-25 and a short cognitive test and provided information on general health and use of low vision aids. Additional information on visual acuity and eye health were collected from the medical record. Our results indicate that ARM patients who seek out low vision services report significant impairment in their vision-specific HRQoL. Their NEI VFQ-25 scores were lower compared to other ARM and low vision rehabilitation samples previously studied. The VFQ subscales with the largest deficits were near and distance visual acuities and psychosocial issues (near vision, distance vision, role difficulties, dependency, social functioning, mental health). These subscale scores were lower for those with greater visual acuity impairment. The VFQ subscale scores most impacted by the disease had wide variability and were higher for those who used low vision aids, suggesting that the NEI VFQ-25 is suitable for measuring further decline and treatment-related improvements. Thus, it should be strongly considered for a multi-site clinical trial on the effectiveness of low vision rehabilitation.     

Visual function and quality of life following vitrectomy and epiretinal membrane peel surgery

AIM: To investigate the effect of epiretinal membrane (ERM) peel on patients' health related quality of life (HR-QOL) and to explore the association between self reported HR-QOL and conventional measures of visual function. METHODS: The National Eye Institute 25 Item Visual Function Questionnaire (VFQ-25) and the 36 Item Short-Form Health Survey (SF-36) were self administered by 20 patients before and 4 months following surgery. Preoperative and postoperative data collected included logMAR near and distant visual acuity (VA), contrast sensitivity, and metamorphopsia. Questionnaire scores were compared preoperatively and postoperatively and their correlation with traditional methods of visual function evaluation analysed. RESULTS: Postoperatively there was no significant improvement in mean logMAR VA. However, eight (40%) subjects improved by two or more ETDRS lines and nine eyes (45%) reached a final VA of 6/18 or better. Metamorphopsia decreased significantly (p = 0.019) and there was significant improvement in VFQ-25 mean scores for the general vision (p = 0.03), distance activities (p = 0.05), and composite score (p = 0.03). Baseline binocular VA was significantly correlated with baseline VFQ-25 composite score (r = 0.631, p = 0.004). CONCLUSIONS: ERM surgery appears to improve patients' subjective perception of visual function as indicated by higher composite scores in VFQ-25 and improved metamorphopsia in the absence of significant improvement in mean logMAR VA.     

The development of the LV Prasad-Functional Vision Questionnaire: a measure of functional vision performance of visually impaired children

PURPOSE: To develop a reliable and valid questionnaire (the LV Prasad-Functional Vision Questionnaire, LVP-FVQ) to assess self-reported functional vision problems of visually impaired school children. METHODS: The LVP-FVQ consisting of 19 items was administered verbally to 78 visually impaired Indian school children aged 8 to 18 years. Responses for each item were rated on a 5-point scale. A Rasch analysis of the ordinal difficulty ratings was used to estimate interval measures of perceived visual ability for functional vision performance. RESULTS: Content validity of the LVP-FVQ was shown by the good separation index (3.75) and high reliability scores (0.93) for the item parameters. Construct validity was shown with good model fit statistics. Criterion validity of the LVP-FVQ was shown by good discrimination among subjects who answered "seeing much worse" versus "as well as"; "seeing much worse" versus "as well as/a little worse" and "seeing much worse" versus "a little worse," compared with their normal-sighted friends. The task that required the least visual ability was "walking alone in the corridor at school"; the task that required the most was "reading a textbook at arm's length." The estimated person measures of visual ability were linear with logarithm of the minimum angle of resolution (logMAR) acuity and the binocular high contrast distance visual acuity accounted for 32.6% of the variability in the person measure. CONCLUSIONS: The LVP-FVQ is a reliable, valid, and simple questionnaire that can be used to measure functional vision in visually impaired children in developing countries such as India.     

The Activity Inventory: an adaptive visual function questionnaire.

PURPOSE: The Activity Inventory (AI) is an adaptive visual function questionnaire that consists of 459 Tasks nested under 50 Goals that in turn are nested under three Objectives. Visually impaired patients are asked to rate the importance of each Goal, the difficulty of Goals that have at least some importance, and the difficulty of Tasks that serve Goals that have both some importance and some difficulty. Consequently, each patient responds to an individually tailored set of questions that provides both a functional history and the data needed to estimate the patient's visual ability. The purpose of the present article is to test the hypothesis that all combinations of items in the AI, and by extension all visual function questionnaires, measure the same visual ability variable. METHODS: The AI was administered to 1880 consecutively-recruited low vision patients before their first visit to the low vision rehabilitation service. Of this group, 407 were also administered two other visual function questionnaires randomly chosen from among the Activities of Daily Living Scale (ADVS), National Eye Institute Visual Functioning Questionnaire (NEI VFQ), 14-item Visual Functioning Index (VF-14), and Visual Activities Questionnaire (VAQ). Rasch analyses were performed on the responses to each VFQ, on all responses to the AI, and on responses to various subsets of items from the AI. RESULTS: The pattern of fit statistics for AI item and person measures suggested that the estimated visual ability variable is not unidimensional. Reading-related and other items requiring high visual resolution had smaller residual errors than expected and mobility-related items had larger residual errors than expected. The pattern of person measure residual errors could not be explained by the disorder diagnosis. When items were grouped into subsets representing four visual function domains (reading, mobility, visual motor, visual information), and separate person measures were estimated for each domain as well as for all items combined, visual ability was observed to be equivalent to the first principal component and accounted for 79% of the variance. However, confirmatory factor analysis showed that visual ability is a composite variable with at least two factors: one upon which mobility loads most heavily and the other upon which reading loads most heavily. These two factors can account for the pattern of residual errors. High product moment and intraclass correlations were observed when comparing different subsets of items within the AI and when comparing different VFQs. CONCLUSIONS: Visual ability is a composite variable with two factors; one most heavily influences reading function and the other most heavily influences mobility function. Subsets of items within the AI and different VFQs all measure the same visual ability variable.     

Influence of cataract and intraocular lens surgery on health-related quality of life

PURPOSE: To evaluate the vision-related quality of life(QOL) in patients undergoing cataract surgery with the Japanese version of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). SUBJECTS AND METHODS: Subjects were 110 patients [70.4 +/- 9.2 (mean +/- standard deviation) years old] undergoing bilateral cataract surgery. Best-corrected visual acuity was 20/30 or worse in both eyes. The VFQ-25 was recorded before and 2 months after phacoemulsification and foldable intraocular lens implantation, and the influence of various clinical parameters was assessed. The VFQ-25 was also recorded in 69 glaucoma patients with visual field defects in both eyes, and in 31 normal subjects. RESULTS: The VFQ-25 scores before cataract surgery were as low as the scores obtained in glaucoma patients. Cataract surgery significantly improved VFQ-25 scores to the level of normal subjects Statistically significant improvements were observed in subscales such as general vision, near activities, distance activities, driving, peripheral vision, color vision, social functioning, dependency, role difficulties, mental health, and total score (p<0.001, paired t-test). The degree of improvement in VFQ-25 scores did not correlate with preoperative or postoperative visual acuity, uncorrected or corrected. The VFQ-25 scores improved more in younger patients, and improvement in the general vision subscale showed a significant negative correlation with age (r= -0.286, p=0.009, Pearson correlation coefficient). The degree of posterior subcapsular cataract in better eyes showed significant correlation with the improvement in subscales, such as distance activity (r =0.413, p<0.001), driving (r= 0.449, p=0.015), social functioning (r=0.308, p= 0.004), mental health (r=0.330, p=0.002), dependency (r=0.323, p=0.003), and total score (r=0.328, p=0.002). Other types of cataract had no correlation. Men tended to show more improvement in VFQ-25 scores by surgery than women, except for the dependency subscale. CONCLUSION: The current study quantitatively demonstrated that vision-related QOL is significantly impaired in patients with cataract, and that cataract surgery dramatically improves patients' QOL.     

A comparison of the sensitivity of EQ-5D, SF-6D and TTO utility values to changes in vision and perceived visual function in patients with primary open-angle glaucoma

ABSTRACT: BACKGROUND: Economic viability of treatments for primary open-angle glaucoma (POAG) should be assessed objectively to prioritise health care interventions. This study aims to identify the methods for eliciting utility values (UVs) most sensitive to differences in visual field and visual functioning in patients with POAG. As a secondary objective, the dimensions of generic health-related and vision-related quality of life most affected by progressive vision loss will be identified. METHODS: A total of 132 POAG patients were recruited. Three sets of utility values (EuroQoL EQ-5D, Short Form SF-6D, Time Trade Off) and a measure of perceived visual functioning from the National Eye Institute Visual Function Questionnaire (VFQ-25) were elicited during face-to-face interviews. The sensitivity of UVs to differences in the binocular visual field, visual acuity and visual functioning measures was analysed using non-parametric statistical methods. RESULTS: Median utilities were similar across Integrated Visual Field score quartiles for EQ-5D (P = 0.08) whereas SF-6D and Time-Trade-Off UVs significantly decreased (p = 0.01 and p = 0.001, respectively). The VFQ-25 score varied across Integrated Visual Field and binocular visual acuity groups and was associated with all three UVs (P [LESS-THAN OR EQUAL TO] 0.001); most of its vision-specific sub-scales were associated with the vision markers. The most affected dimension was driving. A relationship with vision markers was found for the physical component of SF-36 and not for any dimension of EQ-5D. CONCLUSIONS: The Time-Trade-Off was more sensitive than EQ-5D and SF-6D to changes in vision and visual functioning associated with glaucoma progression but could not measure quality of life changes in the mildest disease stages.     

Depression and mood indicators in newly diagnosed glaucoma patients

PURPOSE: To assess depression and mood indicators in subjects newly diagnosed with chronic open-angle glaucoma. DESIGN: Cross-sectional study of data from a randomized clinical trial. METHODS: Newly-diagnosed glaucoma patients enrolled in the Collaborative Initial Glaucoma Treatment Study (CIGTS) responded at baseline to quality-of-life (QOL) telephone interviews. We studied responses to the 33-item Visual Activities Questionnaire (VAQ), six items from a disease-specific Health Perceptions Index (HPI), and eight questions from the Center for Epidemiological Studies Depression Scale (CES-D). We correlated the responses to the HPI and the CES-D with visual acuity (VA) and CIGTS visual field (VF) as well as to the responses to the VAQ. RESULTS: VAQ score was correlated (P < .01 in all cases) with better VA (P = -0.181), better VF (P = 0.139), worse VA (P = -0.128), and worse VF (P = .120). There were also correlations (P ranging from .24 to .38, all P values < or = .001) between patients' perception of their vision (total VAQ score) and each item on the HPI and CES-D. None of the clinical vision measures were associated with any of the CES-D items. The strongest correlation between a clinical measure and an item from the HPI was between worse VF and worry about the possibility of blindness (P = -0.114, P = .005). The odds ratio of reporting mood indicators and symptoms of depression increased with patients' perceptions of worsening visual function but not worsening VA or VF. CONCLUSIONS: In these newly diagnosed glaucoma patients, symptoms of depression and altered mood were related to worse self-reported visual function as assessed by the VAQ, but not to monocular clinical measures of visual function.     

Perceived visual ability for functional vision performance among persons with low vision in the Indian state of Andhra Pradesh

PURPOSE: To determine the distribution of perceived visual ability for functional vision performance among persons with low vision in the Indian state of Andhra Pradesh. METHODS: As part of a population-based epidemiologic study, the Andhra Pradesh Eye Disease Study (APEDS), a 16-item visual function questionnaire was designed and applied to 7363 persons older than 15 years, to record the levels of difficulty perceived by the subjects. Of these, 123 persons were found to have low vision. Rasch analysis was used to convert the ordinal difficulty ratings of these 123 persons into interval measures of perceived visual ability for functional vision. RESULTS: Content validity of the questionnaire was demonstrated by good separation indices (3.17 and 5.44) and high reliability scores (0.91 and 0.97) for person and item parameters. Construct validity was shown with model fit statistics. Criterion validity of the questionnaire was shown by good discrimination among the general vision ratings. The functional situation that required the least visual ability was "reaching an object farther or closer than you thought"; the situation requiring the most visual ability was "recognizing small objects." Bivariate regression analysis determined that for every unit of logMAR visual acuity, perceived visual ability for functional vision decreased by 2.9 logit, which could explain 32% of the variability in the person measure. CONCLUSIONS: The described assessment, across a range of visual problems, is a valid way to measure perceived ability for functional vision in persons with low vision. Perceived visual ability varies with every unit of logarithm of the minimum angle of resolution (logMAR) visual acuity.     

Self-reported visual dysfunction in multiple sclerosis: new data from the VFQ-25 and development of an MS-specific vision questionnaire

PURPOSE: To examine vision-specific health-related quality of life in a cohort of patients with multiple sclerosis (MS) using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25), and to identify content areas for a brief MS-specific vision questionnaire. DESIGN: Cross-sectional survey. METHODS: The VFQ-25 and a modified version of the Optic Neuritis Treatment Trial (ONTT) Patient Questionnaire were administered by in-person interview to 80 patients at the University of Pennsylvania MS Center. Binocular visual acuities were obtained following a standard protocol using retroilluminated Early Treatment Diabetic Retinopathy Study charts. RESULTS: Despite a median binocular visual acuity of 20/16 (20/12.5-20/250), VFQ-25 subscale scores in the MS cohort were significantly lower (worse) compared with those of a published reference group of eye disease-free patients (P =.0001-0.009, two-tailed t tests). Rank-correlations of VFQ-25 composite (overall) scores with visual acuity were modest, but significant (r(s) = 0.33, P =.003), supporting construct validity for VFQ-25 scores in MS populations. Seven additional aspects of self-reported visual dysfunction in MS were also identified. CONCLUSIONS: Patients with MS have a high degree of self-reported visual dysfunction that is not entirely captured by visual acuity. The VFQ-25 is an effective measure of self-reported visual loss in MS. A brief MS-specific vision questionnaire may provide additional useful information when administered concurrently with the VFQ-25 in future investigations of MS and other neuroophthalmologic disorders.     

Vision and visual disability in the daily life of a representative population sample aged 82 years.

A representative population sample (n = 203) aged 82 years was studied to determine the prevalence of impaired vision and visual disability in a cohort previously investigated at the age of 70 years. Visual impairments and disabilities were generally most marked among the non-ambulatory subjects. In the ambulatory group (n = 160) 54% had VA greater than 0.8 and 8% VA less than 0.3. Near vision was also markedly better in this group. About 90% of the ambulatory cases could read J2 or better, read books and watch TV. Statistical analysis showed no sex difference with respect to visual ability for ambulatory subjects. Subjects with a wide range of distance VA were able to read J1 and J2, whereas only one ambulatory patient with J4 or worse had a distance VA above 0.3. To watch TV and manage most of the everyday activities a distance VA of 0.4-0.5 was required. To read newspapers and books a near vision of J2 was needed and for the telephone book J1 was needed. Improvements of near vision obtained by a change of own glasses were small. Hobby and household work proved less dependent on vision. The subjects showed a fairly realistic view of their visual capability, and distance VA was a valuable predictor of visual ability and disability.     

The impact of visual impairment on functional vision of children in rural South India: the Kariapatti Pediatric Eye Evaluation Project

PURPOSE: To determine the impact of visual impairment on functional vision of children in a rural population of south India. METHODS: A visual function questionnaire (LVP-VFQ) was administered to 1194 children aged 7 to 15 years identified through a systematic random sampling technique from 144 hamlets of Kariapatti in rural south India as part of a larger population-based project. Visual acuity estimations and clinical examinations for morbidity were performed in these 1194 children. A Rasch analysis was performed to validate the use of the instrument in this population. Bootstrap estimates (95% confidence intervals) of the regression coefficients were used to compare visual function scores between children with normal sight and children with uncorrected monocular and binocular visual impairment. RESULTS: The mean age of children was 10.3 +/- 2.1 years. The reliability estimates were 0.82 for person ability and 0.88 for item difficulty parameters, according to the Rasch analysis. A separation index of 2.15 was obtained for person measures and 2.74 for item measures, and the mean square infit and outfit statistics were 1.03 (Z(STD) 0.1) and 0.99 (Z(STD) -0.1), respectively. Children with monocular visual impairment (bootstrap estimate [95%CI] -0.05 [-0.08 to -0.01]) and binocular visual impairment (bootstrap estimate [95%CI] -0.09 [-0.11 to -0.07]) were more likely to have functional visual deficits than were normally sighted peers. CONCLUSIONS: Monocular or binocular visual impairment impacts on the functional vision of children in this rural population. Further studies are needed to determine the impact of treatment of visual impairment on functional vision in children of this population.     

白内障患者报告结局条目库的研制

目的:基于Rasch模型研制白内障患者报告结局(PROs)条目库,为准确、全面和动态评估白内障PROs奠定基础.方法:横断面调查研究.根据纳入标准选取我院已确诊的白内障住院患者,采用本课题组前期基于循证医学方法构建的白内障PROs条目池对其进行问卷调查.通过Rasch分析各维度条目选项概率曲线(CPC)、测量精密性、条目拟合指标(infit/outfit MNSQ)、单维性、匹配度和条目功能差异(DIF)等测量特性指标,并反复迭代、提炼,直至得到测量特性优良的条目.采用Pearson相关分析评估各维度和视力的相关性.结果:共纳入296例白内障患者,其中男130例,女166例,年龄70(63,77)岁,受过小学及以上教育者178例(60.1%),术前双眼日常生活视力(LogMAR)为0.0~3.0,中位数为0.6.条目库共纳入3个维度,其中视觉相关活动受限维度23个条目,视觉症状维度14个条目,精神心理健康11个条目,所有条目选项数量均为4个.视觉相关活动受限维度中,选项类别阈值分别为-1.84、0.04、1.79,被试分离信度/被试分离系数(PSR/PSI)为0.93/3.59,主成分分析(PCA)第一成分未解释方差特征值为2.61,匹配度为-0.81,DIF值均小于1;该维度得分与好眼视力(r=0.619,P<0.01)和双眼视力(r=0.622,P<0.01)有相关性.视觉症状维度中,选项类别阈值分别为-1.83、-0.18、2.00,PSR/PSI为0.88/2.68,PCA第一成分未解释方差特征值为2.53,匹配度为-1.35,2个条目在眼部并发症方面的DIF值大于1,其余DIF值均小于1;该维度得分与好眼视力(r=0.482,P<0.01)和双眼视力(r=0.492,P<0.01)有相关性.精神心理健康维度中,选项类别阈值分别为-2.83、0.03、2.80,PSR/PSI为0.88/2.68,PCA第一成分未解释方差特征值为2.79,匹配度为-0.34,所有条目DIF值均小于1;该维度得分与好眼视力(r=0.425,P<0.01)和双眼视力(r=0.426,P<0.01)有相关性.上述所有条目infit和outfit值均介于0.50~1.50之间.结论:基于Rasch分析研制的白内障PROs条目库覆盖了视觉相关活动受限、视觉症状和精神心理健康3个方面,全面地反应了白内障PROs的内涵,且条目简明易懂,临床可操作性好,具有较好的测量特性.     

Vision-related quality of life and visual function after retinal detachment surgery

PURPOSE: To compare the vision-related quality of life (VR QOL) after rhegmatogenous retinal detachment (RD) surgery with that of normal controls and to investigate the relationship between the VR QOL and visual function after surgery for RD. DESIGN: Prospective, consecutive, comparative case series. METHODS: The 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25) was self-administered by 51 RD patients at six months after surgery. Among the patients with RD, 33 underwent pars plana vitrectomy and 18 received scleral buckling. We examined the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), contrast sensitivity with the CSV-1000E (Vector Vision Co, Greenville, Ohio, USA), and low-contrast visual acuity (VA) with the CSV-1000LanC10% (Vector Vision Co). From the data obtained by CSV-1000E, the area under the log contrast sensitivity function (AULCSF) was calculated. The VFQ-25 also was administered to the 46 age-matched normal controls. RESULTS: The VFQ-25 composite score and the subscales associated with near activities, mental health, dependency, and peripheral vision were significantly lower in the RD group than in the normal controls (P < .05). The VFQ-25 composite score significantly correlated with AULCSF (r = 0.354; P < .05) and low-contrast VA (r = -0.475; P < 0.001), whereas there was no correlation between the VFQ-25 composite score and logMAR BCVA (r = 0.172; P = .229). CONCLUSIONS: The VR QOL is significantly impaired in patients after surgery for RD. The disturbance in VR QOL was significantly associated with deterioration of postoperative contrast sensitivity.     

全视网膜光凝术改善PDR患者的视觉相关生活质量及日常视觉功能

目的：评估全视网膜光凝术( PRP )对糖尿病视网膜病变( PDR)患者在视觉相关生活质量及日常视觉功能的影响。方法：研究纳入30例(男13例,女17例)接受全视网膜光凝术治疗糖尿病视网膜病变患者。国家眼科研究所发布的视觉功能量表( VFQ-25)用来评估全视网膜光凝术治疗前后视觉相关生活质量及日常视觉功能。患者在接受全视网膜光凝术治疗前和治疗后6 mo分别填写VFQ-25量表,比较视觉相关生活质量及日常视觉功能差异。运用配对t检验对治疗前后VFQ-25评分对比。结果：全视网膜光凝术治疗前平均VFQ-25综合评分为74.79±15.7,术后平均综合评分为74.08±19.1。术前与术后的平均VFQ-25综合评分无统计学意义( P=0.875)。结论：全视网膜光凝术( PRP)对糖尿病视网膜病变( PDR)患者在视觉相关生活质量及日常视觉功能无不利影响。