Assessing Older Adults' Functional Visual Performance Using the Performance Quality Rating Scale

Visual impairment has distinct impacts on the activities of older adults. Quantifying the functional impact of visual loss would facilitate targeted rehabilitation. The objectives of this study were to: (1) develop an observational assessment of the functional visual performance of older adults using the Performance Quality Rating Scale (PQRS); (2) test the feasibility and inter-rater agreement in a pilot sample of older adults with visual impairment. A convenience sample of older adults with vision loss (N = 20) performed seven pre-selected activities. Performance was videoed (N = 126 videos) and rated by two raters using specific operational definitions. All participants completed the seven activities with the given resources and 90% of videos were successfully rated using the developed PQRS. Inter-rater agreement was substantial (weighted Kappa = 0.71; 95% confidence interval [CI] = [0.64, 0.79]) for all activities. The developed PQRS for functional vision is feasible, with substantial inter-rater agreement, to assess functional vision of older adults in an outpatient setting.

The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 (VA LV VFQ-48): Performance of the Italian version

PURPOSE

The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is among the most validated tools to collect patient-reported outcomes in a low-vision population. We have aimed to conduct a pilot validation of the Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48.

METHODS

The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 was translated using a standardized procedure and then administered to consecutive low-vision patients attending rehabilitation services in three centers. Patients were interviewed by a trained psychologist regarding the individual items of the tool.

RESULTS

We included 131 patients with a mean visual acuity of 0.91 logMAR (standard deviation: 0.42 logMAR), mostly affected by age-related macular degeneration. The Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 showed high internal consistency (Cronbach's alpha: 0.98) and good item-test and item-rest correlation (median: 0.73 and 0.71, respectively). Both the overall score and the subscale (reading, visual motor, mobility and visual information) scores significantly correlated with visual acuity, reading acuity and speed. Reading speed achieved the best absolute correlation with the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 scores (Spearman r: 0.39-0.49).

CONCLUSION

The Italian version of the Veterans Affairs Low-Vision Visual Functioning Questionnaire-48 is a valid tool to assess patients attending low-vision services. Revising a few items may further improve the tool.

Reading Performance Improvements in Patients with Central Vision Loss without Age-Related Macular Degeneration after Undergoing Personalized Rehabilitation Training

PURPOSE

To evaluate the efficacy of a reading rehabilitation program (RRP) in patients with central visual loss (CVL) and assess the impact of the RRP on the quality of life (QoL).

METHODS

The RRP included four in-office and 39 in-home training sessions over 6 weeks. Reading speed, duration, and font size were evaluated during each in-office session. The subjective perception of the QoL was assessed before and after the RRP using the short version of a questionnaire (World Health Organization Quality of Life). A control group who received advice about ocular conditions and low-vision aids also was included.

RESULTS

Seventeen patients with Stargardt's disease (STGD), 11 with adult-onset foveomacular vitelliform dystrophy (AFVD), and eight with myopic macular degeneration (MMD) were included. The control group included five patients each with STGD, AFVD, and MMD. The respective mean corrected distance visual acuities (VAs) in patients with STGD, AFVD, MMD, and the control group were 0.57 ± 0.38, 0.51 ± 0.38, 0.49 ± 0.24, and 0.55 ± 0.25 logarithm of the minimum angle of resolution; the mean corrected near VAs were 0.89 ± 0.20, 1.08 ± 0.17, 0.99 ± 0.34, and 1.18 ± 0.37 (M notation) using low-vision aids. The reading speed, duration, and font size improved in all groups. The RRP groups obtained (p ≤ 0.01) greater improvements than the control group in each reading performance variable assessed. Patients with STGD obtained greater improvements in the subjective evaluation; the control group did not obtain noteworthy improvement in any domain.

CONCLUSIONS

The RRP improved reading performance in patients with CVL and positively impacted the subjective perception of the QoL.

The Veterans Affairs Low Vision Intervention Trial (LOVIT): Design and Methodology

Background Visual impairment is a major public health problem. Vision rehabilitation programs have the potential to restore independence and improve quality of life for persons with permanent vision loss, and few have been evaluated in randomized controlled trials.

Purpose The Veterans Affairs (VA) Low Vision Intervention Trial is a multicenter randomized clinical trial to evaluate the effectiveness of a new outpatient low vision rehabilitation program.

Methods 126 patients with moderate and severe vision loss due to macular diseases are randomized to low vision treatment in an outpatient setting or a usual care control group at two VA facilities in Hines, Illinois, and Salisbury, North Carolina. The primary outcome is the change in visual reading ability from baseline to four months measured with the Veterans Affairs Low Vision Visual Functioning Questionnaire-48 (VA LV VFQ-48). Secondary outcomes compare the mean change in visual ability measured with the VA LV VFQ-48 (overall ability, mobility, visual information processing, visual motor skills) for the treatment and control groups. Costs and cost effectiveness of outpatient treatment are evaluated.

Results The low vision rehabilitation setting, use of a waiting list control group to address ethical issues, development of the treatment protocol, development of a vision function questionnaire for patients to self-report the difficulty they experience performing daily activities, and the use of Rasch analysis to develop and estimate this outcome measure are described.

Limitations If the new low vision rehabilitation program is proven effective, studies will be needed to determine which of the multiple aspects of the intervention are necessary and sufficient.

Conclusions The challenges of conducting clinical trials in a rehabilitation setting and use of a waiting list (deferred treatment) control group extend beyond LOVIT. The design and methods of LOVIT may be applicable to other trials of rehabilitation services and to outcomes for which reliable and valid measurement tools must be developed. Clinical Trials 2007; 4: 650—660. http://ctj.sagepub.com

VA LOVIT II: a protocol to compare low vision rehabilitation and basic low vision

PURPOSE

To compare the effectiveness of low vision rehabilitation (LVR) and basic low vision (LV) in a single masked multicentre randomised controlled trial (RCT).

METHODS

Three hundred and thirty patients eligible for US. Veterans Affairs (VA) healthcare services with primary eye diagnosis (better-seeing eye) of macular disease and best-corrected distance visual acuity of 0.40-1.00 logMAR (6/15 to 6/60 or 20/50 to 20/200 Snellen) are being enrolled at seven VA facilities. All participants receive an optometric LV examination; and they are eligible to receive the same LV devices that are provided without charge. In LVR, a LV therapist dispenses devices and provides 2 or 3 (1½ to 2½ h) therapy sessions with assigned homework to teach effective use of remaining vision and LV devices. Contact time with the therapist depends upon the devices prescribed and the patient's progress in learning the skills that are taught. In basic LV, devices are dispensed by the optometrist without LV therapy. Contact time for dispensing is one hour or less depending on LV devices prescribed. The primary outcome measure is a comparison of the changes in visual reading ability (estimated from patients' difficulty ratings of reading items on the VA LV VFQ-48 questionnaire) between the treatment and control arms from pre-intervention baseline to 4 months (2 months after completion of treatment). Secondary outcome measures are changes in overall visual ability, visual ability domain scores calculated from subsets of items (mobility, visual information processing and visual motor skills), Short Form-36, and Minnesota Low Vision Reading Test scores. Cost-effectiveness analysis will be conducted using VA LV VFQ-48 scores and QALYS computed from EuroQol scores.

RESULTS

A total of 137 patients representing 41.5% of the study target of 330 patients were randomised from October 2010 to March 2012. Among those 137 patients, mean age was 80.2 (S.D. ± 9.9) years at enrollment; 97.1% of the patients were males; 94.2% were white. Mean best corrected VA was 0.65 (S.D. ± 0.3) logMAR (approximately Snellen 6/27 or 20/90) at baseline.

CONCLUSIONS

LOVIT II is the first multicentre RCT comparing the effectiveness and cost-effectiveness of LVR and basic LV for patients with macular diseases and near normal or moderate levels of visual impairment.

Low vision, ADL and hearing assistive device use among older persons with visual impairments

Assistive devices (AD) have long played an important role in occupational therapy practice as a way of enabling activities of daily living (ADL), but no studies to date have investigated the use of low vision AD among older persons with age-related macular degeneration (AMD) as well as devices for ADL performance and hearing. The purpose of this study was to describe AD users and to investigate the association of AD and ADL. A health promotion program versus an individual program was investigated within a randomised design. The study was based on data from 131 participants, 28-months after intervention. Data on prescribed ADs were examined through medical records and registers. The participants in the health promotion program used low vision AD in combination with ADL devices to a higher degree, whereas participants in the individual program used just optical AD. Greater use of non-optical AD within the individual program and greater use of ADL devices within the health promotion program was weakly associated with higher level of ADL dependence. There was no significant association between the number of low vision AD and having a decreased, a maintained or improved level of dependence at 28 months.

Economic evaluation of blind rehabilitation for veterans with macular diseases in the Department of Veterans Affairs

PURPOSE

The Department of Veterans Affairs (VA) Low Vision Intervention Trial (LOVIT) developed an outpatient low-vision programme for patients with macular diseases providing low-vision rehabilitation comparable to VA inpatient blind rehabilitation centres (BRCs). This programme targets veterans who do not need or chose not to participate in a comprehensive inpatient blind rehabilitation programme. We examined costs and consequences using veterans in LOVIT and comparable veterans in an inpatient BRC.

METHODS

We compared costs and consequences between treatment patients who participated in LOVIT, a two-site randomized clinical trial, and a sample of comparable patients who received treatment at a VA inpatient BRC. We measured consequences as the change in functional visual ability from baseline to follow-up (LOVIT: 4 months after randomization; BRC: 3 months after discharge) using the VA Low Vision Visual Functioning Questionnaire (VA LV VFQ-48).

RESULTS

There were 55 LOVIT and 121 BRC patients for our analyses. Average costs were $38,627.3 higher for BRC patients ($5,054.4 +/- $404.7 SD for LOVIT vs. $43,681.7 +/- $8,853.6 SD for BRC, p < 0.0001). Thus, the BRC cost $38,627.3 per patient more than the LOVIT programme (95% CI: $17,414 to $273,482). There was a greater improvement in overall visual ability, mobility, and visual motor skill scores for BRC patients; however, there was no significant difference in improvement in reading ability or visual information processing scores.

CONCLUSIONS

As VA increases outpatient blind rehabilitation services, LOVIT provides a model for expanding outpatient low-vision rehabilitation services for veterans at substantially lower costs than current inpatient BRC services.

Image enhancement of real-time television to benefit the visually impaired

PURPOSE

To examine the use of real-time, generic edge detection, image processing techniques to enhance the television viewing of the visually impaired.

DESIGN

Prospective, clinical experimental study.

METHOD

One hundred and two sequential visually impaired (average age 73.8 +/- 14.8 years; 59% female) in a single center optimized a dynamic television image with respect to edge detection filter (Prewitt, Sobel, or the two combined), color (red, green, blue, or white), and intensity (one to 15 times) of the overlaid edges. They then rated the original television footage compared with a black-and-white image displaying the edges detected and the original television image with the detected edges overlaid in the chosen color and at the intensity selected. Footage of news, an advertisement, and the end of program credits were subjectively assessed in a random order.

RESULTS

A Prewitt filter was preferred (44%) compared with the Sobel filter (27%) or a combination of the two (28%). Green and white were equally popular for displaying the detected edges (32%), with blue (22%) and red (14%) less so. The average preferred edge intensity was 3.5 +/- 1.7 times. The image-enhanced television was significantly preferred to the original (P < .001), which in turn was preferred to viewing the detected edges alone (P < .001) for each of the footage clips. Preference was not dependent on the condition causing visual impairment. Seventy percent were definitely willing to buy a set-top box that could achieve these effects for a reasonable price.

CONCLUSIONS

Simple generic edge detection image enhancement options can be performed on television in real-time and significantly enhance the viewing of the visually impaired.

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.