Measurement of visual functioning following first and second eye cataract surgery using Vision-Related Activity Limitation Item Bank.

PURPOSE: This study aims to compare visual functioning (VF) after first or second eye cataract surgery using the vision-related activity limitation (VRAL) item bank. METHODS: This prospective, interventional study included 787 patients (mean age, 58.2 years) with cataract undergoing cataract surgery (first eye surgery with/out ocular comorbidity, second eye surgery with/out ocular comorbidity) at a tertiary eye care center, South India, who were administered the item bank pre- and at 6 weeks postoperatively to assess change in VF. Rasch analysis was used to estimate VF at both time points, and responsiveness to cataract surgery was calculated as effect size (ES) which was interpreted as small (≤ 0.2), moderate (0.3-0.7), and large (≥ 0.8). RESULTS: Mean best-corrected logMAR VA in surgical eye improved significantly postoperatively compared to preoperative VA (0.20 ± 0.40 vs. 1.19 ± 0.96; P < 0.0001) across all groups. Patients reported significant and large improvements in VF postoperatively across all groups: largest ES for first eye surgery without comorbidity (1.87 [95% CI, 1.61, 2.13]) and smallest for second eye without ocular comorbidity (1.55 [95% CI, 1.22, 1.88]). Compared to patients undergoing second eye surgery, first eye surgery patients reported significantly lower VF preoperatively (-0.72 ± 2.39 vs. 0.17 ± 2.34 logits; P < 0.0001), and a larger change in VF postoperatively (3.71 ± 2.33 logits vs. 4.27 ± 2.83 vs.; P = 0.004). CONCLUSIONS: Cataract surgery resulted in large and significant improvements in VF, regardless of ocular comorbidity and first or second eye surgery. The VRAL item bank is a useful tool to measure responsiveness to cataract surgery.

Refractive error and vision related quality of life.

BACKGROUND: To investigate and compare the vision-related quality of life (QOL) in different types of refractive error (RE). METHODS: This cross-sectional study was performed on 200 subjects, categorized into four groups of 50 each, consisting of subjects with myopia, hyperopia, astigmatism, and emmetropia, the latter being the control group. The mean age of the participants was 23.88 ± 5.87 (range, 15 to 38: 110 females and 90 males). RE was defined as myopia, spherical equivalent (SE) < -0.25 diopters (D), hyperopia, SE > + 0.25 D, astigmatism, cylinder < -0.25 D, and emmetropia (-0.25 ≤ SE(D) ≤ + 0.25, cylinder ≥ -0.25). Groups are subdivided into very low magnitudes of RE (0.50 and 0.75) and significant RE (1.00 ≤). Vision-related QOL was assessed using the Persian version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25). The NEI-VFQ was scored as visual function and socioemotional scales using Rasch analysis. RESULTS: Corrected myopia, astigmatism, uncorrected myopia, and hyperopia had a lower vision-related QOL than emmetropes. (P < 0.001). Vision-related QOL in myopic subjects was lower than that in astigmatic participants. Very low myopes, who often do not use correction, had a significantly lower QOL than other groups. CONCLUSION: Individuals with refractive errors experience a lower QOL score than those without. Notably, the adverse impact on QOL score is significantly greater in myopic cases, particularly very low myopia, compared to other refractive errors. Therefore, it is strongly recommended not to neglect managing very low myopia since it may improve participants' QOL.

The incidence of falls after first and second eye cataract surgery: a longitudinal cohort study.

OBJECTIVE: To compare fall incidence, and visual acuity and refractive status, before surgery and after first and second eye cataract surgery. DESIGN, SETTING: Prospective observational study in eight tertiary referral ophthalmology clinics in public hospitals in Sydney, Melbourne, and Perth. PARTICIPANTS: People aged 65 years or more referred for bilateral age-related cataract surgery during 2013-16, followed for maximum of 24 months after study entry or until six months after second eye surgery, whichever was shorter. MAIN OUTCOME MEASURES: Primary outcome: age- and sex-adjusted incidence of falls. SECONDARY OUTCOMES: visual acuity and refractive error. RESULTS: The mean age of the 409 included participants was 75.4 years (SD, 5.4 years); 220 were women (54%). Age- and sex-adjusted fall incidence prior to surgery was 1.17 (95% CI, 0.95-1.43) per year, 0.81 (95% CI, 0.63-1.04) per year after first eye surgery, and 0.41 (95% CI, 0.29-0.57) per year after second eye surgery. For the 118 participants who underwent second eye surgery and participated in all follow-up visits, age- and sex-adjusted incidence before (0.80 [95% CI, 0.55-1.15] falls per year) and after first eye surgery (0.81 [95% CI, 0.57-1.15] falls per year) was similar, but was lower after second eye surgery (0.32 [95% CI 0.21-0.50] falls per year). Mean habitual binocular visual acuity (logMAR) was 0.32 (SD, 0.21) before surgery, 0.15 (SD, 0.17) after first eye surgery, and 0.07 (SD, 0.15) after second eye surgery. CONCLUSIONS: First eye surgery substantially improves vision in older people with cataract, but second eye surgery is required to minimise fall incidence. Timely cataract surgery for both eyes not only optimises vision in older people with cataract, but also reduces their risk of injury from falls.

Capturing the experiences of patients with inherited optic neuropathies: a systematic review of patient-reported outcome measures (PROMs) and qualitative studies.

PURPOSE: To identify and comprehensively evaluate studies capturing the experience of individuals affected by an inherited optic neuropathy (ION), focusing on patient-reported outcome measures (PROMs) and qualitative studies where the health status and quality of life (QoL) of these individuals have been explored. METHODS: Systematic review of five databases using a search strategy combining four concepts: (1) ION; (2) QoL and health status; (3) PROMs; and (4) qualitative research. Studies assessing the impact of ION on any QoL domain using a PROM or qualitative methodology were included and appraised, using criteria based on the COSMIN checklist (for PROM studies) and the CASP checklist (for qualitative studies). RESULTS: Of 1326 unique articles identified, six studies were included. Five PROMs were identified: Visual Function Index (VF-14); Hospital Anxiety and Depression Scale (HADS); a novel graphical online assessment tool (NGOAT) for reporting emotional response to vision loss; a new PROM informed by the DSM-V Criteria for Major Depressive Disorder; and an interpersonal and career 'impact rating' PROM. The psychometric performance of included PROMs were poorly described. Qualitative studies found that vision loss resulted in psychosocial losses including loss of social and communication skills and loss of independence and freedom. Factors that modified the response to vision loss were also identified. CONCLUSION: The current PROMs used by individuals with ION have poor content coverage, primarily measuring activity limitation and emotional well-being, and insufficient reporting of psychometric performance. There is a need to develop a PROM for individuals ION to report their experiences of living with their condition.

Comparing the measurement properties of visual analogue and verbal rating scales.

PURPOSE: Utilising Rasch analysis on the Keratoconus Outcome Research Questionnaire (KORQ) data, we explored the hypothesis that the KORQ with discrete verbal rating scale (VRS) would demonstrate better psychometric properties and provide less noise in measurement than with a visual analogue scale (VAS). METHODS: The KORQ is a keratoconus-specific patient-reported outcome measure; it has activity limitation and symptoms scales. The KORQ scales with two different rating scales (VAS and a discrete 4-response VRS) were completed by self-administration by people with keratoconus. For each KORQ scale, Rasch analysis-based psychometric properties were compared between the two versions. Rasch analysis was also used to optimise rating scale functioning when disordered thresholds were observed. RESULTS: 118 (mean age ± SD, 46.4 ± 0.4 years) and 169 (45.4 ± 14.7 years) people completed the KORQ with VAS and VRS, respectively. Both scales demonstrated high measurement precision. However, the VAS rating scale was disordered (6 out of 11 categories dysfunctional) and had two misfitting items. Conversely, the VRS had ordered categories and no misfitting items. For the disordered VAS, ordering was achieved only after collapsing 11 categories into four categories. In comparison to the KORQ with VRS, the repaired VAS had lower measurement precision, test information, variance explained by the measure, poor targeting, and reduced measurement range. CONCLUSIONS: The KORQ demonstrated superior psychometric properties when measured using a VRS than with a VAS. This illustrates the advantages of verbal rating scales for a patient-reported outcome measurement over a visual analogue scale.

Factors affecting quality of life in keratoconus.

PURPOSE: To identify the factors affecting the quality of life (QoL) in adults with keratoconus, using the disease-specific Keratoconus Outcomes Research Questionnaire (KORQ). METHODS: In this cross-sectional study, 574 patients with keratoconus completed the 29-item KORQ (18-item activity limitations and 11-item symptoms subscales) and demographic information. Based on mean corneal curvature to grade keratoconus severity, participants were categorised into four groups: mild <48 dioptres [D]; moderate: 48 to 53 D; advanced: 54 to 55 D and severe: >55D. Rasch analysis was used to assess the psychometric properties and to score the KORQ. Multivariable regression was performed to determine the independent impact of age, sex, laterality, severity and duration of keratoconus, education, employment status and mode of treatment for keratoconus on activity limitations and symptoms. RESULTS: Mean (SD) age was 24.5 (5.1) years. 304 (53%), 160 (28%), 26 (4%) and 84 (15%) belonged to keratoconus groups 1, 2, 3 and 4, respectively. Rasch analysis demonstrated the 'activity limitations' and 'symptoms' KORQ subscales to possess good psychometric properties. Statistically significant associations were found between activity limitation score and the following measures: visual acuity (VA) in the better-seeing eye (r = -0.10, p = 0.01); VA in the worse-seeing eye (r = -0.09, p = 0.04) and ocular aberrations (r = -0.13, p = 0.008) in the worse-seeing eye. Statistically significant associations were also found between symptoms score and mean corneal curvature in the better-seeing eye (r = -0.10, p = 0.02). In regression models, female sex was associated with 21% worse symptom score than male (ß = -0.33, 95% CI, -0.09, -0.59, p = 0.01) and working people experienced clinically and statistically significantly greater trouble from symptoms compared to those not working (ß =0.44, 95% CI, 0.17, 0.70, p = 0.001). CONCLUSIONS: People with keratoconus have poorer QoL in terms of activity limitations if they have poorer VA and greater wavefront aberrations, and in terms of symptoms if they are female and employed.

Does non-strabismic amblyopia affect the quality of life of adults? Findings from a qualitative study.

PURPOSE: While much is known about the psychosocial impacts of strabismus, little is known about the effects of non-strabismic amblyopia on quality of life (QoL). The aim of this study was to explore the long-term impacts of anisometropic amblyopia. METHODS: A phenomenological qualitative investigation was carried out on a sample of adults with anisometropic amblyopia. Subjects participated in in-depth telephone interviews and described how their eye condition affected different aspects of their life. The interviews were audio-recorded, transcribed verbatim and analysed iteratively to form emergent themes. RESULTS: Sixteen participants took part in the study (median age: 21.5 years; range: 18-36 years; 11 male and 5 female). Six themes emerged: (1) symptoms experienced by participants, (2) concerns and apprehensions, (3) emotional impacts, (4) activity limitations, (5) hassle and inconveniences and (6) economic and career implications. Symptoms reported by participants ranged from glare to difficulty concentrating. They were extremely concerned about the safety of their better eye and lived with several doubts and anxieties. Negative emotions such as grief and disappointment due to eye care negligence in childhood was apparent. Guilt and regretful feelings were present in those who did not comply with past treatment. Participants expressed several limitations in driving, reading, mobility (e.g., using stairs) and tasks requiring high resolution. Reported inconveniences associated with coping with their eye condition included having to travel across the country in search of a cure for their amblyopia. Economic impacts ranged from costs associated with accessing eye care and management to career choices being compromised. CONCLUSION: Lived experiences of people with anisometropic amblyopia indicate that the QoL impacts are multifaceted and substantial, even in the absence of strabismus. The results have the potential to influence patient-practitioner relationship by opening newer horizons to communication and care while managing adult amblyopes.

Item banks for measurement of refractive error-specific quality of life.

PURPOSE: To evaluate the psychometric properties of refractive error-specific quality of life (QoL) item banks and assess their performance using computerised adaptive testing (CAT) simulations. METHODS: In this cross-sectional study a 392-item questionnaire, grouped under 11 QoL domains, was interviewer-administered to 305 people with refractive error [mean age ± S.D., 30.5 ± 14.1 (range (18 to 83) years; male, 50.5%; mean ± S.D. spherical equivalent refractive error -2.4 ± 2.9 (range: -15.0 to +11.0) Dioptres; spectacles (n = 257), contact lens (n = 37), refractive surgery (n = 25), uncorrected refractive error (n = 57)]. Rasch analysis was conducted on each QoL domain using the Andrich rating scale model to investigate parameters including response category functioning, person- and item-reliability, infit and outfit statistics, unidimensionality, targeting, differential item functioning and local item dependency. The resulting item banks underwent CAT simulations in 1,000 cases with 'high' and 'moderate' precision stopping rules. RESULTS: Rasch analysis iterations resulted in 13 refractive error-specific item banks (Convenience, Health concerns, Economic, Activity limitation, Mobility, Emotional, Social, Visual symptoms frequency, Visual symptoms severity, Visual symptoms bothersome, Comfort symptoms frequency, Comfort symptoms severity and Comfort symptoms bothersome), containing a total of 366 items. The item banks had good psychometric properties including satisfactory measurement precision, infit and outfit statistics and unidimensionality. In CAT simulations, the mean number of items required to achieve high and moderate measurement precision was 9.4 and 4.7, respectively. CONCLUSION: Overall, refractive error-specific QoL item banks show promise in their ability to comprehensively and precisely evaluate a range of quality of life parameters. These items banks when administered using a CAT system offer unique outcome tools for implementation in clinical trials, healthcare and research.

Prevalence of Strabismus and Its Impact on Vision-Related Quality of Life: Results from the German Population-Based Gutenberg Health Study.

PURPOSE: This study investigates the prevalence of manifest strabismus and its subtypes in adulthood and analyzes the risk factors and its impact on vision-related quality of life (VRQoL). DESIGN: The Gutenberg Health Study (GHS) is a population-based, observational cohort study. A cross-sectional analysis of the baseline examination was conducted. PARTICIPANTS: Participants aged 35 to 74 years were included (n = 15 010). METHODS: All participants were examined with a comprehensive ophthalmologic and general examination including the Hirschberg corneal reflex test to detect manifest strabismus. The following risk factors were analyzed: age, sex, socioeconomic status, birth weight, maternal age at birth, anisometropia, astigmatism, spherical equivalent, low visual acuity in the worse seeing eye (≥1.3 logMAR), and cardiovascular factors, and included in multivariable logistic regression analysis. Lifetime period prevalence and point prevalence of manifest strabismus were computed, and VRQoL was compared between participants with and without strabismus. MAIN OUTCOME MEASURE: Strabismus prevalence. RESULTS: A total of 14 700 participants (age, 55.0±11.1 years; 49.5% were female) were included in this analysis. The weighted prevalence of ever having strabismus was 2.9% (2.6%-3.2%), and the point prevalence for concomitant strabismus was 2.5% (2.3%-2.8%). Esotropia was twice as frequent as exotropia, and 2 participants had paralytic strabismus. Concomitant strabismus was associated with age 65 to 69 years (odds ratio [OR], 0.13 [0.05-0.39], P < 0.001); age 70 to 74 years (OR, 0.14 [0.05-0.4], P < 0.001); anisometropia (>1.0 diopters [D]: OR, 3.61 [2.32-5.62], P < 0.001; >2.0 D: OR, 6.93 [4.23-11.35], P < 0.001); astigmatism (≥1.0 D: OR, 2.09 [1.42-3.08], P < 0.001; ≥2.0 D: OR, 3.74 [2.35-5.97], P < 0.001); spherical equivalent (per diopter: OR, 1.43 [1.33-1.53], P < 0.001); and low visual acuity in the worse seeing eye (≥1.3 logMAR: OR, 21.7 [11.2-42.0], P < 0.001). VRQoL was lower in participants with strabismus compared with participants without strabismus in adjusted analysis (B = -5.96, P < 0.001). CONCLUSIONS: Strabismus is a frequent chronic eye condition that is associated with a lower VRQoL. Individuals with anisometropia, astigmatism, and hyperopia are more likely to have strabismus. In addition, low visual acuity in the worse eye was linked to strabismus prevalence.

Validation of a vision-related activity scale for patients with retinitis pigmentosa.

PURPOSE: There have been few systematic reports of vision-related activity limitations of people with retinitis pigmentosa (RP). We report a merging of data from the National Eye Institute Visual Function Questionnaire (NEI-VFQ) obtained in five previous studies. We asked whether the Vision Function Scale (VFS; Pesudovs et al., 2010) which was developed for cataract patients would apply in this new population (condition). METHODS: Five hundred ninety-four individuals completed a total of 1753 questionnaires, with 209 participants providing responses over at least 4 years. Rasch analysis showed that the 15-item VFS was poorly targeted. A new instrument created by adding four driving-related items to the VFS had better targeting. As an indirect validation, VFS-plus person scores were compared to visual field area measured using a Goldmann perimeter, to the summed score for the combined 30-2 and 30/60-1 Humphrey Field Analyzer programs (HFA), to 30-Hz full-field cone electroretinogram (ERG) amplitude, and to ETDRS visual acuity. Changes in VFS-plus person scores with age and between four common heredity groups were also examined. RESULTS: The Rasch model of responses to the 19 VFS-plus items had person and item separation of 2.66 and 24.43 respectively. The VFS-plus person scores were related to each vision measure (p < 0.001). Over a five-year period, there was a reduction in person scores of 0.5 logits (p < 0.001). Person scores fell by an average of 0.34 logits per decade (p < 0.0001). Participants with an X-linked hereditary pattern had, on average, lower person scores (p < 0.001). CONCLUSIONS: The VFS-plus instrument quantified a highly-significant annual reduction in perceived vision-related ability over a five-year period. The outcome was consistent with clinical measures of vision, and detected lower perceived vision-related ability in participants with X-linked disease. It may be of use in future studies, but this needs to be tested in a representative population sample.

Psychometric Properties of an Indian Translation of the Vision-related Activity Limitation Item Bank in Cataract.

SIGNIFICANCE: The Indian translated and culturally adapted version of the vision-related activity limitation (VRAL) item bank is a validated instrument to assess the difficulty in performing daily activities by cataract patients and can also be used to capture self-reported changes in ability to perform daily activities after cataract surgery. PURPOSE: The purpose of this study was to document (a) translation, cross-cultural adaptation of VRAL item bank into an Indian language, and (b) its validation using Rasch analysis in a South Indian cataract population. METHODS: At the first stage, a translated Indian version of VRAL item bank was produced using recommended procedures. At the second stage, Rasch analysis was performed to investigate its psychometric properties in 787 cataract patients (mean age, 58.2 years; mean ± SD visual acuity [logMAR], 1.19 ± 0.96 at baseline in eye for surgery) including comparison with the original version. RESULTS: Post-translation equivalence of meaning was achieved, but some English phrases required cross-cultural adaptation. Subsequently, all items were appropriate for the Indian culture, and VRAL item bank demonstrated excellent measurement precision (7.39). Dimensionality assessment suggested that VRAL construct may contain other dimensions such as self-care and visual search, and mobility. Self-care and visual search formed a unidimensional measure but was highly correlated with main VRAL dimension, and the removal of its items weakened precision of the main VRAL dimension measurement. Taken together, evidence favored retaining self-care and visual search items in a larger VRAL item bank. Mobility subscale lacked adequate measurement precision, so it was not examined further; again, items were retained in VRAL scale because they strengthened its measurement properties. Majority of items (99%) did not demonstrate notable differential item functioning (>1.0 logit) by presenting visual acuity (median, 0.20 logMAR) in the better-seeing eye. CONCLUSIONS: Items in the translated Indian VRAL item bank measure the same construct as the English version and fulfilled the psychometric requirements for use in cataract patients.

Development and Psychometric Assessment of Novel Item Banks for Hereditary Retinal Diseases.

SIGNIFICANCE: This study develops psychometrically valid item banks across 10 areas of quality of life (QoL) specific to people with hereditary retinal diseases, which will enable clinicians and researchers to explore the impact of hereditary retinal diseases across all aspects of QoL. PURPOSE: The purpose of this study was to assess the psychometric properties of hereditary retinal disease QoL item banks using Rasch analysis and demonstrate the effectiveness of a computerized adaptive testing (CAT) system in obtaining precise measurement of QoL using only a few items. METHODS: The hereditary retinal disease item banks were answered by 233 participants (median age, 58 years; range, 18 to 94 years; female participants, 59%). The hereditary retinal disease item banks cover 10 QoL domains: activity limitation, mobility, emotional, social, convenience, economic, health concerns, visual symptoms, ocular comfort symptoms, and general symptoms. Rasch analysis assessed the psychometric properties of the 10 item banks and provided item calibrations for the development of CAT. Computerized adaptive testing simulations were performed to calculate the average number of items required to gain precise measurement of each QoL domain. RESULTS: The convenience, economic, visual symptoms, and the social domains formed unidimensional scales. However, the activity limitation and health concerns domains demonstrated multidimensionality and required major modifications to resolve this, which resulted in four new QoL domains, namely, reading, driving, lighting, and concerns about the disease progression. In total, 10 item banks underwent CAT simulation testing, which indicated that 8 to 12 items were required to gain precise measurement of each QoL domain. CONCLUSIONS: We have developed 10 psychometrically valid item banks to measure the QoL domains relevant to people with hereditary retinal diseases. On average, only 5 and 10 items were required to gain measurement at moderate and high precision, respectively.

Functional limitations recognised by adults with amblyopia and strabismus in daily life: a qualitative exploration.

PURPOSE: Patients' perceptions about the functional impact of amblyopia and strabismus in daily life have not been explored extensively. Therefore, this study aimed to explore the lived experiences of adults with these conditions and understand the functional limitations they face in their day-to-day life. METHODS: A qualitative study design was adopted. Participants over 18 years of age, with a primary diagnosis of amblyopia (with or without strabismus) were recruited from the community and various eye care practices in South Australia and Victoria, Australia. Participants took part in either focus group discussions or individual interviews and described the functional limitations they experienced in their daily life due to their eye condition. These sessions were audio recorded, transcribed verbatim, coded inductively, and analysed iteratively to form emergent themes. RESULTS: Thirty-seven adult participants took part in the study: 23 (62%) had strabismic amblyopia; 5 (14%) anisometropic amblyopia;, 7 (19%) combined-mechanism amblyopia; and 2 (5%) deprivational amblyopia. Their median age was 54 years (range: 21-82 years) and 19 (51%) were female. Participants reported several challenges in performing everyday tasks such as driving (e.g. judging distances, changing lanes), reading (e.g. fine print, reading for prolonged time) and sports (e.g. catching a ball). They also articulated trouble in navigating safely (e.g. using stairs, bumping into objects), performing work-tasks (e.g. taking longer than peers to complete tasks) and other routine tasks (e.g. chopping vegetables with care). CONCLUSIONS: Several functional limitations were encountered by adults living with amblyopia and strabismus. Participants recognised these limitations in their normal day-to-day life and related the challenges they faced to symptoms associated with their eye condition. By presenting rich in-depth qualitative data, the paper demonstrates qualitative evidence of the functional impacts associated with amblyopia and strabismus.

Developing an item bank to measure the coping strategies of people with hereditary retinal diseases.

PURPOSE: Our understanding of the coping strategies used by people with visual impairment to manage stress related to visual loss is limited. This study aims to develop a sophisticated coping instrument in the form of an item bank implemented via Computerised adaptive testing (CAT) for hereditary retinal diseases. METHODS: Items on coping were extracted from qualitative interviews with patients which were supplemented by items from a literature review. A systematic multi-stage process of item refinement was carried out followed by expert panel discussion and cognitive interviews. The final coping item bank had 30 items. Rasch analysis was used to assess the psychometric properties. A CAT simulation was carried out to estimate an average number of items required to gain precise measurement of hereditary retinal disease-related coping. RESULTS: One hundred eighty-nine participants answered the coping item bank (median age = 58 years). The coping scale demonstrated good precision and targeting. The standardised residual loadings for items revealed six items grouped together. Removal of the six items reduced the precision of the main coping scale and worsened the variance explained by the measure. Therefore, the six items were retained within the main scale. Our CAT simulation indicated that, on average, less than 10 items are required to gain a precise measurement of coping. CONCLUSIONS: This is the first study to develop a psychometrically robust coping instrument for hereditary retinal diseases. CAT simulation indicated that on an average, only four and nine items were required to gain measurement at moderate and high precision, respectively.

Constructing Item Banks for Measuring Quality of Life in Refractive Error.

SIGNIFICANCE: Existing patient-reported outcome instruments in refractive error are paper-based questionnaires. They are not comprehensive and psychometrically robust. This study has identified the content of the refractive error-specific item banks that aim to provide comprehensive and scientific measurement of refractive error-specific quality of life. PURPOSE: The purpose of this study was to identify minimally representative, optimally informative, and efficient sets of items for measuring quality of life in people with refractive error. METHODS: First, items were identified from existing patient-reported outcome instruments. Second, items were developed from qualitative studies with people with refractive error (48 and 101 in-depth interviews in Australia and Nepal, respectively). Third, classification and selection of items were done based on a set of systematic criteria using an iterative process of binning and winnowing. The resulting items underwent cognitive testing with people with refractive error in Australia and in Nepal. Each step was guided by an expert panel consensus. RESULTS: We retrieved 792 items from the existing patient-reported outcome instruments. From the interviews conducted in Australia, a total of 2367 comments were coded into 807 initial items. Similarly, from the interviews conducted in Nepal, 3477 comments were coded into 914 initial items. After binning and winnowing, followed by cognitive testing, a final set of items comprising 337 items for the Item-pool (Australia) and 308 items for the Item-pool (Nepal), both spanning 12 domains, was obtained. Forty-seven percent of items were common across the two item pools. In the Item-pool (Nepal), 65% items were common for corrected and uncorrected refractive error. CONCLUSIONS: We identified the content of two different sets of item banks to comprehensively measure the impact of refractive error on quality of life for people in Australia and Nepal, which may be applicable to high-income country settings and low- and middle-income country settings, respectively. Future work aims to develop computer-adaptive testing system to administer the item banks, resulting in useful measurement tools for researchers, clinicians, and policy planners.

Development of a Keratoconus-Specific Questionnaire Using Rasch Analysis.

PURPOSE: To develop and validate a keratoconus-specific quality of life (QoL) questionnaire: the Keratoconus Outcomes Research Questionnaire (KORQ). METHODS: The study was carried out in three phases. Phase I: content identifications: items were identified based on an extensive literature review, open-ended patient mail survey, and expert consultations. Each item was scored on a visual analog scale (VAS). Phase II: pilot testing using Rasch analysis. Phase III: testing psychometric properties of the final version of the KORQ. RESULTS: Phase I identified 44 items across 3 different content areas: activity limitation (26), symptoms (20), and convenience (8). The 44-item KORQ was self-administered to 158 people with keratoconus. The 44-item KORQ was multidimensional. Unidimensionality was restored by separating items across three content areas (subscales) as identified in phase I. The activity limitation and symptoms subscales demonstrated adequate measurement precision, but convenience (precision, 1.01) did not. Hence, the convenience subscale was discarded. Rasch analysis revealed that the VAS was disordered. The ordering of the VAS was restored by collapsing categories into 4. An iterative Rasch analysis guided item-removal resulted into a 29-item KORQ (18-item activity limitation and 11-item symptoms). The VAS was replaced by a discrete 4-option labeled categorical rating scale, and it was self-administered by 169 people with keratoconus. Both the subscales demonstrated good psychometric properties. The KORQ scores strongly correlated with visual acuity and contrast sensitivity demonstrating its construct validity. CONCLUSIONS: The 29-item KORQ was a psychometrically robust and valid instrument to assess the impact of keratoconus on activity limitation and symptoms.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review.

SIGNIFICANCE: This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward. PURPOSE: A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments. METHODS: Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria. RESULTS: One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments. CONCLUSIONS: This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

Impact of refractive error on quality of life: a qualitative study.

IMPORTANCE: This study qualitatively explores the impact of refractive error on adults, particularly after correction. BACKGROUND: The study aimed to explore the impact of refractive error on quality of life. DESIGN: Cross-sectional; in-depth telephone and face-to-face semistructured interviews; qualitative study with inductive and deductive processes. PARTICIPANTS: Forty-eight adults with refractive error (including presbyopia) were recruited from the Flinders Vision, the Ashford Advanced Eye Care and among Flinders University staff and students, in South Australia. METHODS: The interviews were audio-recorded, transcribed verbatim, coded and analysed using thematic analysis. MAIN OUTCOME MEASURES: Themes and categories RESULTS: The median age of the participants was 49 years (min: 22 years; max: 76 years). Most of them were female: (29; 59%). Most of them (36; 75.0%) had myopia followed by hyperopia (12; 25.0%). Twenty-two (45.8%) participants had astigmatism. Similarly, 23 (47.9%) of them were presbyopes. Most of the participants (39; 81.3%) wore glasses; 17 (35.4%) used contact lenses, and 17 (35.4%) had undergone refractive surgery. A total of 2367 comments were coded. Thematic analysis resulted into six themes that informed about quality of life issues in people with refractive error. Concerns about cosmetic appearance, personal health and safety, difficulties in day-to-day activities and inconveniences rendered in daily life were identified as the most important themes. CONCLUSIONS AND RELEVANCE: The findings of this study enrich the understanding on the issues important in people with refractive error. The quality of life issues identified will be used to develop a refractive error-specific item bank.

Methods to Develop the Eye-tem Bank to Measure Ophthalmic Quality of Life.

PURPOSE: There is an increasing demand for high-standard, comprehensive, and reliable patient-reported outcome (PRO) instruments in all the disciplines of health care including in ophthalmology and optometry. Over the past two decades, a plethora of PRO instruments have been developed to assess the impact of eye diseases and their treatments. Despite this large number of instruments, significant shortcomings exist for the measurement of ophthalmic quality of life (QoL). Most PRO instruments are short-form instruments designed for clinical use, but this limits their content coverage often poorly targeting any study population other than that which they were developed for. Also, existing instruments are static paper and pencil based and unable to be updated easily leading to outdated and irrelevant item content. Scores obtained from different PRO instruments may not be directly comparable. These shortcomings can be addressed using item banking implemented with computer-adaptive testing (CAT). Therefore, we designed a multicenter project (The Eye-tem Bank project) to develop and validate such PROs to enable comprehensive measurement of ophthalmic QoL in eye diseases. METHODS: Development of the Eye-tem Bank follows four phases: Phase I, Content Development; Phase II, Pilot Testing and Item Calibration; Phase III, Validation; and Phase IV, Evaluation. CONCLUSIONS/DISCUSSION: This project will deliver technologically advanced comprehensive QoL PROs in the form of item banking implemented via a CAT system in eye diseases. Here, we present a detailed methodological framework of this project.

Item Banking Enables Stand-Alone Measurement of Driving Ability.

PURPOSE: To explore whether large item sets, as used in item banking, enable important latent traits, such as driving, to form stand-alone measures. METHODS: The 88-item activity limitation (AL) domain of the glaucoma module of the Eye-tem Bank was interviewer-administered to patients with glaucoma. Rasch analysis was used to calibrate all items in AL domain on the same interval-level scale and test its psychometric properties. Based on Rasch dimensionality metrics, the AL scale was separated into subscales. These subscales underwent separate Rasch analyses to test whether they could form stand-alone measures. Independence of these measures was tested with Bland and Altman (B&A) Limit of Agreement (LOA). RESULTS: The AL scale was completed by 293 patients (median age, 71 years). It demonstrated excellent precision (3.12). However, Rasch analysis dimensionality metrics indicated that the domain arguably had other dimensions which were driving, luminance, and reading. Once separated, the remaining AL items, driving and luminance subscales, were unidimensional and had excellent precision of 4.25, 2.94, and 2.22, respectively. The reading subscale showed poor precision (1.66), so it was not examined further. The luminance subscale demonstrated excellent agreement (mean bias, 0.2 logit; 95% LOA, -2.2 to 3.3 logit); however, the driving subscale demonstrated poor agreement (mean bias, 1.1 logit; 95% LOA, -4.8 to 7.0 logit) with the AL scale. CONCLUSIONS: These findings indicate that driving items in the AL domain of the glaucoma module were perceived and responded to differently from the other AL items, but the reading and luminance items were not. Therefore, item banking enables stand-alone measurement of driving ability in glaucoma.