Purpose. To explore the psychometric properties of the Impact of Vision Impairment scale (IVI) by using Rasch analysis. methods. Three hundred fourteen first-time referrals to low-vision clinics completed the 32-item IVI. The data were Rasch-analyzed with a partial credit model using RUMM2020 software (RUMM Laboratory, Perth, WA, Australia). The overall fit of the model, response scale, individual item fit, differential item functioning, unidimensionality, and person-separation reliability were assessed. results. Initially, 26 items displayed disordered thresholds. However, collapsing the response scale to three categories (4 items) and four categories (28 items) produced ordered response thresholds for all items. Four items with high proportions of missing responses, poor spread, high skewness, and deviation between observed and expected model curves were then removed. This adjustment produced overall fit to the Rasch model (item–trait interaction χ² = 118.3; P = 0.32). The final mean (SD) person and item fit residuals ere 0.06 (0.85) and −0.20 (1.45), respectively. The person-separation reliability was 0.9, indicating that the scale was able to discriminate between several different groups of participants. The revised scale was well targeted to the participants, with similar mean locations for items (0.00) and persons (0.16). A significant difference between participants of mild, moderate, and severe visual impairment (ANOVA; P 0.001) supported the criterion validity of the Rasch-scaled IVI. conclusions. The results provide support for the measurement properties of the Rasch-scaled 28-item version of the IVI and of its potential for assessing outcomes of low-vision rehabilitation. A raw score-to-Rasch person measure conversion is supplied.

Purpose of review This review summarizes the recent literature of the impact of cataract surgery from the patient's perspective, with a focus on second-generation patient reported outcome (PRO) measures that used Rasch analysis to explore their data. Recent findings Irrespective of the instrument utilized, the overriding conclusion is that cataract surgery unequivocally improves vision-specific functioning and several aspects of vision-specific quality of life. The benefit of cataract surgery, however, on generic health is less clear, due to limited vision-related items. Evidence suggests that cataract surgery also improves visual functioning in comorbid eye disease, especially in the early stages. Similarly, second eye cataract surgery appears to improve visual ability beyond that achieved with first eye surgery. Recently, there has been a shift toward second-generation, Rasch-validated PROs to assess cataract surgery outcomes and large gains in visual function have been demonstrated. Importantly, measurement precision is dramatically improved compared with the original first-generation instruments. Summary Cataract surgery-induced improvements in visual acuity are translated by considerable gains in real life activities, emotional and social life components. The utilization of second-generation instruments and modern psychometric methods, however, appears to be the best current strategy to optimize the impact of cataract surgery on health-related quality of life.

Purpose. To report associations of visual impairment and the main causes of vision loss with falls in an older Asian population. methods. The population-based Singapore Malay Eye Study examined 3280 (78.7% response rate) Malay adults 40 to 80 years of age. Details about any fall in the previous 12 months and personal and sociodemographic information were collected. Presenting visual acuity (PVA) was measured. Mild or moderate visual impairment (0.3 < logMar < 1.0), severe visual impairment (logMAR ≥ 1.0), and the primary causes of visual impairment were determined by ophthalmologists at examination. results. Of the 3280 participants, 3266 (99.6%) provided information about falls. Of these, 14.7% (n = 480) reported having fallen in the past 12 months. After adjustment for gender, age, body mass index, history of angina, heart attack, stroke, hypertension, diabetes, and self-rated health, the results showed that severe visual impairment in the worse eye significantly increased the risk of falling (60%; OR = 1.6; 95% CI 1.1 to 2.3). Severe visual impairment in one eye and mild or moderate visual impairment in the other also doubled the risk of falls (OR = 2.1; 95% CI 1.4–3.1). Having glaucoma (n = 21) increased the risk of falling by more than fourfold (OR = 4.2; 95% CI 1.2–12.3) after adjustment for visual acuity. Although mild or moderate visual impairment was not significantly associated with falls, odds ratios tended toward the direction of risk. conclusions. Findings from this Asian population provide further evidence in support of the association between severe visual impairment and falls in older persons.

Purpose. To evaluate the effectiveness of a multidisciplinary low-vision rehabilitation program on quality of life evaluated by the Impact of Vision Impairment (IVI) instrument. methods. First-time referrals to low-vision clinics were assessed before and after rehabilitation (3–6 months). Rasch analysis was used to estimate the three IVI subscale and overall values on an interval scale. A mixed between–within subjects ANOVA was used to identify whether presenting visual acuity had an interaction effect with rehabilitation change. Cohen d values were used to estimate the magnitude of the change and the standardized response mean (SRM) procedure was selected to determine the clinical significance of the rehabilitation-induced changes. results. One hundred twenty-four women and 68 men (mean age, 80.3 years) completed the rehabilitation. Most had age-related macular degeneration (62%, 119) and were moderately to severely vision impaired (<6/18; 78%, 149). After rehabilitation, significant improvements were recorded for the overall IVI score (P = 0.006) and two subscales: reading and accessing information and emotional well-being (P = 0.007 and 0.009, respectively). No significant improvement was found on the mobility and independence subscale (P = 0.07). The magnitude of the postintervention improvement was found to be relatively moderate (Cohen d = 0.17–0.30) and clinically modest (SRM = 0.22–0.42). conclusions. Significant improvements in overall quality of life and two specific areas of daily living in people with low vision were found, although the magnitude and clinical significance of the rehabilitation-induced gains were modest. Further investigation in other models of low-vision rehabilitation is needed to optimize quality of life gains in people with low vision.