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ABSTRACT: PURPOSE: To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. METHODS: Participants included 23 persons (Mean age = 33 ± 12 yrs) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a State bioptic driving program, and 23 visually normal age-matched controls (Mean age = 33 ± 12 yrs). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection and frequency of bioptic telescope use. RESULTS: Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. CONCLUSIONS: Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.
Investigative ophthalmology & visual science 05/2013; · 3.43 Impact Factor
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ABSTRACT: OBJECTIVE: To examine rates of visual impairment of older adults in assisted living facilities (ALFs). METHODS: Vision screening events were held at 12 ALFs in Jefferson County, Alabama, for residents above 60 years of age. Visual acuity, cognitive status, and presence of eye conditions were assessed. RESULTS: A total of 144 residents were screened. Of these 67.8% failed distance screening, 70.9% failed near screening, and 89.3% failed contrast sensitivity screening. A total of 40.4% of residents had cognitive impairment and 89% had a least one diagnosed eye condition. Visual acuities did not differ significantly between cognitive status groups or with greater numbers of eye conditions. DISCUSSION: This study is the first to provide information about vision impairment in the assisted living population. Of those screened, 70% had visual acuity worse than 20/40 for distance or near vision, and 90% had impaired contrast sensitivity. Cognitive impairment accounted for a small percentage of the variance in near vision and contrast sensitivity.
Journal of Aging and Health 01/2013; · 1.56 Impact Factor
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ABSTRACT: PURPOSE: To examine in a population-based sample of 2,000 drivers aged ≥ 70 years old, the independent association between higher-order visual processing impairment and motor vehicle collision (MVC) rate during the prior five years. METHODS: Three higher-order visual processing screening tests were administered since previous research found associations between impaired performance on these screens and MVC involvement. They included an estimate of visual processing speed under divided attention conditions (Useful field of view (UFOV) subset 2); Trails B, a paper and pencil test of visual processing speed also involving problem solving, executive function, and working memory; and the visual closure subtest of the Motor Free Visual Perception Test (MVPT) examining the ability to recognize objects only partially visible. Potentially confounding variables were also assessed including demographics, general cognitive status, visual acuity, and contrast sensitivity. MVC involvement was determined by accident reports from the Alabama Department of Public Safety and t driving exposure was estimated from the Driving Habits Questionnaire. RESULTS: MVC rates (for at-fault and all MVCs) were significantly higher for those older drivers with impairments in any of the three visual processing screening tests. After adjustment for potentially confounding influences, the association between MVC rate and Trails B remained significant whereas the association with MVPT and UFOV did not. CONCLUSIONS: This population-based study of drivers ≥ 70 years old suggests that a paper and pencil test assessing higher-order visual processing skills is independently associated with a recent history of MVC involvement.
Investigative ophthalmology & visual science 01/2013; · 3.43 Impact Factor
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ABSTRACT: PURPOSE: To determine the relationship between refractive error as measured by autorefraction and that measured by trial frame refraction among a sample of adults with vision impairment seen in a university-based low vision clinic and to determine if autorefraction might be a suitable replacement for trial frame refraction. METHODS: A retrospective chart review of all new patients ≥ 19 years old seen over an 18-month period was conducted and the following data collected: age, gender, primary ocular diagnosis, entering distance visual acuity, habitual correction, trial frame refraction, autorefraction and distance visual acuity measured after trial frame refraction. Trial frame refraction and autorefraction were compared using paired t-tests, Intra-class correlations and Bland-Altman plots. RESULTS: Final analyses included 440 patients for whom both trial frame refraction and autorefraction data were available for the better eye. Participants were mostly female (59%) with a mean age of 68 years (SD=20). Age-related macular degeneration was the most common etiology for vision impairment (44%). Values for autorefraction and trial frame refraction were statistically different, but highly correlated for the spherical equivalent power (r=0.92), the cylinder power (r=0.80) and overall blurring strength (0.89). Although the values of the cross-cylinders J0 and J45 were similar, they were poorly correlated (0.08 and0.15, respectively). The range of differences in spherical equivalent power was large (-8.6 to 4.9). CONCLUSIONS: Autorefraction is highly correlated with trial frame refraction. Differences are sometimes substantial, making autorefraction an unsuitable substitute for trial frame refraction.
Investigative ophthalmology & visual science 11/2012; · 3.43 Impact Factor
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ABSTRACT: Purpose: Vision impairment is an important public health concern. Accurate information regarding visual health and eye care utilization is essential to monitor trends and inform health policy interventions aimed at addressing at-need populations. National surveys provide annual prevalence estimates but rely on self-report. The validity of self-reported information regarding eye disease has not been adequately explored. Methods: This cross-sectional study compared self-report of eye care utilization and eye disease with information obtained from medical records. The study population was 2001 adults aged 70 years and older who completed the Behavioral Risk Factor Surveillance System's Visual Impairment and Access to Eye Care Module. Cohen's kappa (κ) was used to assess agreement. Results: Agreement between self-report and medical records was substantial for eye care utilization (κ = 0.64) and glaucoma (κ = 0.73), moderate for macular degeneration (κ = 0.40) and diabetic retinopathy (κ = 0.47) and slight for cataracts (κ = 0.18). Self-report tended to overestimate the number of subjects who visited an eye care provider in the previous year, and underestimated the prevalence in all but one (glaucoma) of the four eye diseases evaluated. Conclusions: Though agreement was substantial for self-report of eye care utilization, results of the current study suggest that national estimates based on self-report overestimate eye care utilization.
Current eye research 10/2012; · 1.51 Impact Factor
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ABSTRACT: BACKGROUND: Safe driving performance depends on visual skills yet little is known about the prevalence of vision impairments in older drivers and the eye conditions that cause them. This study is a population-based examination of the prevalence of vision impairment and major ophthalmological conditions among drivers aged 70 and older. METHODS: The source population was a random sample of 2,000 licensed drivers aged 70 and older residing in north central Alabama. All had driven within the past 3 months. Binocular visual acuity and contrast sensitivity were assessed. The Useful Field of View subtest 2 and Trails B assessed visual processing speed. Ophthalmological diagnoses for cataract, intraocular lens placement, glaucoma, diabetic retinopathy, age-related macular degeneration, and diabetic retinopathy were obtained through medical records from the most recent eye examination. RESULTS: Ninety-two percent of drivers had visual acuity of 20/40 or better; only two drivers (0.1%) had acuity worse than 20/100. Ninety-three percent had normal contrast sensitivity (≥1.5). About 40% had slowed visual processing speed (44%, Useful Field of View; 38%, Trails B). The most common eye condition was cataract, with more than half having cataract in one or both eyes (56%); yet by the 80s and 90s, the prevalence was low, with most drivers having undergone cataract surgery and intraocular lens placement. CONCLUSIONS: This population-based study suggests that serious impairment in central vision-visual acuity or contrast sensitivity-is rather uncommon in older drivers; however, slowed visual processing speed is common.
The Journals of Gerontology Series A Biological Sciences and Medical Sciences 09/2012; · 4.60 Impact Factor
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ABSTRACT: To evaluate prescribed optical device use in terms of frequency and perceived usefulness among people with age-related macular degeneration (AMD). We also sought to determine the tasks for which they were using their prescribed low vision device(s).
One hundred ninety-nine patients with AMD presenting for the first time to the low vision service were recruited from a university-based clinic. Prior to the low vision evaluation and device prescription, they completed the National Eye Institute Visual Function Questionnaire 25, Center for Epidemiological Studies Depression Scale, Short Portable Mental Status Questionnaire, and a general health questionnaire. The low vision evaluation included best-corrected Early Treatment of Diabetic Retinopathy Study visual acuity, MNREAD testing, microperimetry, prescription, and dispensing of optical low vision devices. Telephone follow-up interviews were conducted about device usage 1-week, 1-month, and 3-months postintervention.
One hundred eighty-one participants were prescribed low vision devices. Of them, 93% completed all 3 follow-up interviews. Intensive users (≥1 hours/day) of devices were similar in demographic and visual characteristics to non-intensive users (<1 hours/day), except for habitual reading acuity and speed as well as contrast sensitivity. Overall, device use increased slightly over 3 months of follow-up. Magnifiers were reported to be moderately-to-extremely useful by >80% of participants at all time points except the 1-month follow-up for hand magnifiers (75%). High plus spectacles were the least frequently prescribed device and rated as moderately-to-extremely useful by 70%, 74%, and 59% at 1 week, 1 month, and 3 months, respectively. Most participants used their devices for leisure reading, followed by managing bills. Very few devices (n = 3, <1%) were not used at any time point.
Patients with AMD who are provided with prescribed optical low vision devices do use them and perceive them as useful, especially for leisure reading activities. High rates of usage were maintained over 3 month.
Optometry and vision science: official publication of the American Academy of Optometry 08/2012; 89(9):1336-42. · 1.53 Impact Factor
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ABSTRACT: To identify through focus groups of visually impaired children and their parents, relevant content for a vision-targeted health-related quality of life (HRQoL) questionnaire designed for children aged 6 to 12 years.
Six focus groups of children with vision impairment aged 6 to 12 years and six focus groups of their parents were conducted by trained facilitators using a guided script. Sessions were recorded, transcribed, and coded as per a standardized protocol for content analysis. Comments were placed in thematic categories and each was coded as positive, negative, or neutral.
Twenty-four children (mean age: 9.4 years) with vision impairment from a variety of causes and 23 parents participated in the study. The child focus groups generated 1,163 comments, of which 52% (n = 599) were negative, 12% (n = 138) were neutral, and 37% (n = 426) were positive. The three most common topical areas among children were: glasses and adaptive equipment (18%), psychosocial (14%), and school (14%). The parent focus groups generated 1952 comments of which 46% (n = 895) were negative, 16% (n = 323) were neutral, and 38% (n = 734) were positive. The three most common topical areas among parents were: school (21%), expectations or frustrations (14%), and psychosocial (13%).
Pediatric vision impairment has significant effects on HRQoL, as reported by children with vision impairment and their parents in their own words. These findings will provide the content to guide construction of a survey instrument to assess vision-specific, HRQoL in children with vision impairment.
Optometry and vision science: official publication of the American Academy of Optometry 08/2012; 89(9):1409-16. · 1.53 Impact Factor
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ABSTRACT: Little is known about older drivers' preferences and attitudes about instrumentation design in vehicles. Yet visual processing impairments are common among older adults and could impact their ability to interface with a vehicle's dashboard. The purpose of this study is to obtain information from them about this topic, using focus groups and content analysis methodology. A trained facilitator led 8 focus groups of older adults. Discussion was stimulated by an outline relevant to dashboard interfaces, audiotaped, and transcribed. Using multi-step content analysis, a trained coder placed comments into thematic categories and coded comments as positive, negative, or neutral in meaning. Comments were coded into these categories: gauges, knobs/switches, interior lighting, color, lettering, symbols, location, entertainment, GPS, cost, uniformity, and getting information. Comments on gauges and knobs/switches represented half the comments. Women made more comments about getting information; men made more comments about uniformity. Positive and negative comments were made in each category; individual differences in preferences were broad. The results of this study will be used to guide the design of a population-based survey of older drivers about instrument cluster format, which will also examine how their responses are related to their visual processing capabilities.
Accident; analysis and prevention 11/2011; 43(6):2024-9. · 1.65 Impact Factor
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ABSTRACT: To compare self-reported driving difficulty by persons with hemianopic or quadrantanopic field loss with that reported by age-matched drivers with normal visual fields; and to examine how their self- reported driving difficulty compares to ratings of driving performance provided by a certified driving rehabilitation specialist (CDRS).
Participants were 17 persons with hemianopic field loss, 7 with quadrantanopic loss, and 24 age-matched controls with normal visual fields, all of whom had current driver's licenses. Information was collected via questionnaire regarding driving difficulties experienced in 21 typical driving situations grouped into three categories (involvement of peripheral vision, low visibility conditions, and independent mobility). On-road driving performance was evaluated by a CDRS using a standard assessment scale.
Drivers with hemianopic and quadrantanopic field loss expressed significantly more difficulty with driving maneuvers involving peripheral vision and independent mobility, compared to those with normal visual fields. Drivers with hemianopia and quadrantanopia who were rated as unsafe to drive based upon an on-road assessment by the CDRS were no more likely to report driving difficulty than those rated as safe.
This study highlights aspects of driving that hemianopic or quadrantanopic persons find particularly problematic, thus suggesting areas that could be focused on driving rehabilitation. Some drivers with hemianopia or quadrantanopia may inappropriately view themselves as good drivers when in fact their driving performance is unsafe as judged by a driving professional.
Current eye research 03/2011; 36(3):270-7. · 1.51 Impact Factor
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ABSTRACT: Purpose: To compare self-reported driving difficulty by persons with hemianopic or quadrantanopic field loss with that reported by age-matched drivers with normal visual fields; and to examine how their self- reported driving difficulty compares to ratings of driving performance provided by a certified driving rehabilitation specialist (CDRS). Method: Participants were 17 persons with hemianopic field loss, 7 with quadrantanopic loss, and 24 age-matched controls with normal visual fields, all of whom had current driver’s licenses. Information was collected via questionnaire regarding driving difficulties experienced in 21 typical driving situations grouped into three categories (involvement of peripheral vision, low visibility conditions, and independent mobility). On-road driving performance was evaluated by a CDRS using a standard assessment scale. Results: Drivers with hemianopic and quadrantanopic field loss expressed significantly more difficulty with driving maneuvers involving peripheral vision and independent mobility, compared to those with normal visual fields. Drivers with hemianopia and quadrantanopia who were rated as unsafe to drive based upon an on-road assessment by the CDRS were no more likely to report driving difficulty than those rated as safe. Conclusion: This study highlights aspects of driving that hemianopic or quadrantanopic persons find particularly problematic, thus suggesting areas that could be focused on driving rehabilitation. Some drivers with hemianopia or quadrantanopia may inappropriately view themselves as good drivers when in fact their driving performance is unsafe as judged by a driving professional.
02/2011; 36(3):270-277.
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ABSTRACT: To examine associations between retinal thickness and rod-mediated dark adaptation in older adults with non-exudative age-related maculopathy (ARM) or normal macular health.
A cross-sectional study was conducted with 74 adults ≥ 50 years old from the comprehensive ophthalmology and retina services of an academic eye centre. ARM presence and disease severity in the enrolment eye was defined by the masked grading of stereofundus photos using the Clinical Age-Related Maculopathy grading system. High-definition, spectral-domain optical coherence tomography was used to estimate retinal thickness in a grid of regions in the macula. Rod-mediated dark adaptation, recovery of light sensitivity after a photo-bleach, was measured over a 20-min period for a 500 nm target presented at 5° on the inferior vertical meridian. Main outcomes of interest were retinal thickness in the macula (μm) and parameters of rod-mediated dark adaptation (second slope, third slope, average sensitivity, final sensitivity).
In non-exudative disease retinal thickness was decreased in greater disease severity; thinner retina was associated with reductions in average and final rod-mediated sensitivity even after adjustment for age and visual acuity.
Impairment in rod-mediated dark adaptation in non-exudative ARM is associated with macular thinning.
The British journal of ophthalmology 02/2011; 95(10):1427-32. · 2.92 Impact Factor
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ABSTRACT: To compare eye and head movements, lane keeping, and vehicle control of drivers with hemianopic and quadrantanopic field defects with controls, and to identify differences in these parameters between hemianopic and quadrantanopic drivers rated safe to drive by a clinical driving rehabilitation specialist compared with those rated as unsafe.
Eye and head movements and lane keeping were rated in 22 persons with homonymous hemianopic defects and 8 with quadrantanopic defects (mean age, 53 years) who were ≥6 months post-injury and 30 persons with normal fields (mean age, 53 years). All were licensed to drive and were current drivers or aimed to resume driving. Participants drove a 6.3-mile route along non-interstate city roads under in-traffic conditions. Vehicle control was assessed objectively by vehicle instrumentation for speed, braking, acceleration, and cornering.
As a group, drivers with hemianopic or quadrantanopic defects drove slower, exhibited less excessive cornering or acceleration, and executed more shoulder movements than the controls. Those drivers with hemianopic or quadrantanopic defects rated as safe also made more head movements into their blind field, received superior ratings regarding eye movement extent and lane position stability, and exhibited less sudden braking and drove faster than those rated unsafe.
Persons with hemianopic and quadrantanopic defects rated as safe to drive compensated by making more head movements into their blind field, combined with more stable lane keeping and less sudden braking. Future research should evaluate whether these characteristics could be trained in rehabilitation programs aimed at improving driving safety in this population.
Investigative ophthalmology & visual science 01/2011; 52(3):1220-5. · 3.43 Impact Factor
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ABSTRACT: Driving is the primary means of personal travel in many countries and relies heavily on vision for its successful execution. Research over the past few decades has addressed the role of vision in driver safety (motor vehicle collision involvement) and in driver performance (both on-road and using interactive simulators in the laboratory). Here we critically review what is currently known about the role of various aspects of visual function in driving. We also discuss translational research issues on vision screening for licensure and re-licensure and rehabilitation of visually impaired persons who want to drive.
Vision research 11/2010; 50(23):2348-61. · 2.29 Impact Factor
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ABSTRACT: In 129 community-dwelling older adults, feedback regarding qualification for an insurance discount (based on a visual speed of processing test; Useful Field of View) was examined as a prospective predictor of change in self-reported driving ability, driving avoidance, and driving exposure over 3 months, along with physical, visual, health, and cognitive variables. Multiple regression models indicated that after controlling for baseline scores on the outcome measures, failure to qualify was a significant predictor of increased avoidance over 3 months (p = .02) but not change in self-rated driving ability or exposure. Female gender (p = .03) was a significant predictor of subsequent lower self-rated driving ability. Overall, the findings of this study provide support for the role of feedback in the self-monitoring of older adults' driving behavior through avoidance of challenging driving situations but not through driving exposure or self-rated driving ability.
The Gerontologist 11/2010; 51(3):367-78. · 2.48 Impact Factor
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Cynthia Owsley
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ABSTRACT: Given the increasing size of the older adult population in many countries, there is a pressing need to identify the nature of aging-related vision impairments, their underlying mechanisms, and how they impact older adults' performance of everyday visual tasks. The results of this research can then be used to develop and evaluate interventions to slow or reverse aging-related declines in vision, thereby improving quality of life. Here we summarize salient developments in research on aging and vision over the past 25 years, focusing on spatial contrast sensitivity, vision under low luminance, temporal sensitivity and motion perception, and visual processing speed.
Vision research 10/2010; 51(13):1610-22. · 2.29 Impact Factor
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ABSTRACT: Few studies have provided population-based estimates of the vision impairment, eye disease and eye care in the United States. Using data from the Behavioral Risk Factor Surveillance System (BRFSS) this study reports the overall and age-race-specific prevalence of self-reported vision impairment, eye diseases, and eye care utilization among older adults.
Between 2005 and 2008 residents aged 50 and older in 17 states responded to BRFSS questions concerning difficulty with distance and near vision-related tasks, self-reported eye diseases and reported eye care insurance and service utilization.
The overall prevalence of difficulty with distance and near vision was 16.6 and 32.8%, respectively with no meaningful change with increasing age. The prevalence of cataract, glaucoma, and macular degeneration was 19.6%, 6.4, and 5.8%; all of which increased dramatically with age. Nearly 69% of Whites and Blacks and 65% of Hispanics visited an eye care provider in the past year. Overall, among the approximately one-third of participants who did not visit an eye care provider in the past year, half indicated that they did not have any reason to go and 20% cited it was due to cost/insurance.
The continued and expanding use of the BRFSS Visual Impairment and Access to Eye Care module represents a unique opportunity to obtain population-based estimates of vision impairment, eye disease and perhaps most uniquely, eye care utilization. Moreover, the integration of this and other BRFSS modules will provide researchers the opportunity to evaluate the relationship between these estimates and other measures of health status and health care utilization. However, the self-reported nature of the BRFSS data is an important limitation that must be considered when interpreting the results.
Current eye research 06/2010; 35(6):451-8. · 1.51 Impact Factor
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ABSTRACT: To present the bother subscales of the Nursing Home Vision-Targeted Health-Related Quality of Life Questionnaire (NHVQoL) and to examine their relationship to the original NHVQoL subscales and objective measures of visual function.
395 nursing home residents completed the bother subscales. Associations between bother subscales and original subscales and objectively measured vision were evaluated.
Mean bother scores ranged from 1.97 to 2.30, reflecting an average rating of "a little" bother. For 20 NHVQoL items, more than 50% of participants reported "a lot" of bother. All NHVQoL original subscale scores were moderately correlated with bother subscales (p < .0001). Bother subscales and visual acuity were not highly correlated.
Nursing home residents are bothered by reductions in vision-targeted health-related quality of life. The NHVQoL bother subscales may probe the personal burden of visual problems in this population that is not captured by the original subscales or objectively measuring visual function.
Journal of Aging and Health 03/2010; 22(4):504-21. · 1.56 Impact Factor
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ABSTRACT: To assess the association between Ginkgo biloba extract (GBE) use and glaucoma.
Self-reported data on the past 12 months of GBE use and the presence of glaucoma were obtained from the 2002 National Health Interview Survey, a nationally-representative population-based sample. Crude and adjusted associations between GBE use and glaucoma were estimated.
Those who reported having glaucoma were 26% less likely to report GBE use; however, this was not statistically significant. After adjustment for potentially confounding demographic and medical characteristics, there was no difference in GBE use among those who did and did not report having glaucoma.
The results of this study fail to support a significant relationship between GBE use over the past 12 months and having glaucoma, though this finding requires replication in a prospective study. Moreover, whether GBE is efficacious in treating glaucoma patients remains an issue for future research.
Journal of glaucoma 10/2009; 18(7):543-5. · 1.74 Impact Factor
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ABSTRACT: To describe characteristics of services, providers, and patients in low-vision rehabilitation entities serving adults in the United States.
Entities (excluding Veterans Affairs clinics) were identified through professional associations, Web searches, and a telephone survey to retina practices. A census obtained information on entity types, provider types, rehabilitation services available, and clientele. Surveys were administered by telephone, fax, e-mail, or mail, whichever was preferred by the respondent.
A total of 1228 low-vision rehabilitation service entities were identified, with 608 surveyed (49.5% response rate). Almost half (42.7%) were private optometry practices. State agencies had the highest number of clients per week (45.0 clients per week) whereas private optometry practices had the lowest (4.1 clients per week). Most (> or =88.0%) established rehabilitation goals, fit optical aids with basic training, and conducted eye examinations. Scanning, eccentric viewing, orientation and mobility, and advanced device training were less commonly offered (25%-50% of entities). Central vision impairment was the most common deficit (74.1% of clients), with age-related macular degeneration being the most common cause (67.1%). Among the clients, 85.9% had problems reading and 67.7% had problems driving; 44.9% had adjustment disorders. Almost 1 in 3 clients was aged 80 years or older.
This census for the first time characterizes usual-care low-vision rehabilitation services in the United States for nonveteran adults.
Archives of ophthalmology 05/2009; 127(5):681-9. · 3.86 Impact Factor
