Biomedical subjects

Cynthia Owsley

Publications and source records attributed to Cynthia Owsley.

13 recordsLinked to original sources

PubMed2003

The efficacy of an educational intervention in promoting self-regulation among high-risk older drivers.

Visual processing impairment increases crash risk among older drivers. Many older drivers meet the legal requirements for licensing despite having vision impairments that elevate crash risk. In this study, 365 older drivers who were licensed, visually-impaired, and crash-involved in the prior year were randomly assigned to an intervention group or usual-eye-care control group to evaluate the efficacy of an educational intervention that promoted the performance of self-regulatory practices. The educational curriculum was designed to change self-perceptions about vision impairment and how it can impact driver safety and to promote the avoidance of challenging driving situations through self-regulation, leading to reductions in driving exposure. Analyses compared the intervention and control groups at pre-test and 6 months post-test with respect to self-reported perceptions about vision and driving practices. At post-test, drivers who had received the educational intervention were more likely to acknowledge that the quality of their eyesight was less than excellent, report a higher frequency of avoiding challenging driving situations (e.g. left-turns) and report performing more self-regulatory practices (e.g. three right-turns) as compared to controls. Additionally, drivers in the educational intervention group reported significantly fewer days, fewer places and fewer trips made per week as compared to those not receiving the educational intervention. These findings imply that visually-impaired older drivers at higher risk for crash involvement may benefit from educational interventions by reducing their driving exposure and increasing their avoidance of visually challenging driving situations. A critical future step in this research program will be to examine whether this educational intervention has an impact on the safety of these high-risk older drivers by reducing their crash involvement in the years following the educational intervention.

Aged↗

PubMed2003

Visual dysfunction, neurodegenerative diseases, and aging.

The four most common sight-threatening conditions in older adults in North America are cataract, ARM, glaucoma, and diabetic retinopathy. Even in their moderate stages, these conditions cause visual sensory impairments and reductions in health-related quality of life, including difficulties in daily tasks and psychosocial problems. Many older adults are free from these conditions, yet still experience a variety of visual perceptual problems resulting from aging-related changes in the optics of the eye and degeneration of the visual neural pathways. These problems consist of impairments in visual acuity, contrast sensitivity, color discrimination, temporal sensitivity, motion perception, peripheral visual field sensitivity, and visual processing speed. PD causes a progressive loss of dopaminergic cells predominantly in the retina and possibly in other areas of the visual system. This retinal dopamine deficiency produces selective spatial-temporal abnormalities in retinal ganglion cell function, probably arising from altered receptive field organization in the PD retina. The cortical degeneration characteristics of AD, including neurofibrillary tangles and neuritic plaques, also are present in the visual cortical areas, especially in the visual association areas. The most prominent electrophysiologic change in AD is a delay in the P2 component of the flash VEP. Deficits in higher-order visual abilities typically are compromised in AD, including problems with visual attention, perceiving structure from motion, visual memory, visual learning, reading, and object and face perception. There have been reports of a visual variant of AD in which these types of visual problems are the initial and most prominent signs of the disease. Visual sensory impairments (e.g., contrast sensitivity or achromatopsia) also have been reported but are believed more reflective of cortical disturbances than of AD-associated optic neuropathy.

Age Factors↗

PubMed2003

Impact of cataract surgery on self-reported visual difficulties: comparison with a no-surgery reference group.

PURPOSE: To examine the impact of cataract surgery on older adults' self-reported visual difficulties and compare them with those of patients with cataract who declined surgery over the same period. SETTING: Twelve area practices. METHODS: This was a consecutive chart review over a 6-month period. Primary inclusion criteria were 55 years or older, cataract in 1 or both eyes with 20/40 visual acuity or worse (best corrected, distance), and no previous cataract surgery in either eye. The Activities of Daily Vision Scale (ADVS) and visual acuity, contrast sensitivity, and disability glare tests were administered at baseline and at a 1-year follow-up visit. RESULTS: This study comprised 245 patients, 156 of whom elected to have cataract surgery and 89 of whom declined. Those electing surgery were more likely to be white, female, and have worse visual acuity and no ocular comorbidities. At baseline, ADVS subscale scores ranged from 53 to 76 in the surgery group and from 72 to 89 in the no-surgery group. In the surgery group, subscale scores improved by 15 to 21 points on average at the 1-year follow-up; scores were unchanged or worse in the no-surgery group over this period. This difference between the groups remained statistically significant after adjustment for group baseline differences in demographics, vision, and ADVS score. In the surgery group, visual acuity improvement in the first eye was an independent predictor of increases in the ADVS overall score and night driving and glare disability subscales; contrast sensitivity was an independent predictor of improvement in the night driving subscale. A reduction in disability glare in the second eye was independently linked to increases in the overall ADVS score and the night driving, near vision, and glare disability subscales. CONCLUSIONS: Baseline findings suggest that cataract patients who have surgery have more difficulty in visual tasks than those who decline surgery. After surgery, patients reported less difficulty with visual tasks. In the no-surgery group, no change was reported. Improvements in visual acuity and contrast sensitivity and reductions in disability glare after surgery were independently linked to improvements in ADVS scores.

Activities of Daily Living↗

PubMed2003

Contrast sensitivity.

Spatial contrast is a physical dimension referring to the light-dark transition of a border or an edge in an image that delineates the existence of a pattern or an object. Contrast sensitivity refers to a measure of how much contrast a person requires to see a target. Contrast-sensitivity measurements differ from acuity measurements; acuity is a measure of the spatial-resolving ability of the visual system under conditions of very high contrast, whereas contrast sensitivity is a measure of the threshold contrast fur seeing a target. Today the most common methods for measuring contrast sensitivity are chart-based systems that can be mounted on the wall. These charts use test targets that are either sine-wave gratings or letters. Which specific chart a clinician selects should be guided by his or her purpose in using contrast sensitivity for patient management. In the research setting, chart selection should rest on ensuring that the scientific aims of the study are met. Contrast-sensitivity tests can provide useful information by revealing in some conditions visual loss not identifiable through visual acuity tests, by providing another method of monitoring treatments, and by providing a better understanding of visual performance problems faced by persons with vision impairment.

Contrast Sensitivity↗

PubMed2003

The association between cataract and mortality among older adults.

CONTEXT: Previous research has suggested that persons with cataract have an increased risk of death. OBJECTIVE: To compare the mortality experience of patients with cataract who elect surgery, patients with cataract who do not elect surgery, and patients without cataract independent of potentially confounding risk factors. DESIGN: Cohort study. SETTING: Ophthalmology and optometry clinics affiliated with the Callahan Eye Foundation Hospital in Birmingham, Alabama. PATIENTS: 384 persons with and without cataract. MAIN OUTCOME MEASURE: Mortality. RESULTS: Of the 384 study subjects, 286 had cataract, of whom 200 elected to have cataract surgery. Patients with cataract who did and did not elect surgery had significantly higher mortality compared to those without cataract (crude mortality rate ratio (MRR) 3.9 (95% confidence interval (CI) 1.5-9.8) and 7.3 (95% CI 2.8-19.1), respectively). After adjustment for age, gender, race, education, chronic medical conditions, smoking, drinking, depression, and cognitive status, the no-surgery cataract group had an elevated mortality rate (MRR 3.2 (95% 1.2-9.0)), compared to the no-cataract group, with a borderline elevation in MR for the surgery group (MRR 2.0 (95% 0.8-5.9). Limiting the study population to non-diabetics or those without concurrent eye conditions (glaucoma, maculopathy, retinopathy) did not materially influence the adjusted MRRs although the precision of the estimates was reduced. CONCLUSIONS: The results suggest that older persons with cataract, in particular those who decline surgery, have an increased risk of death, supporting the hypothesis that age-related cataract reflects systemic as well as localized ocular disease.

Aged↗

PubMed2003

Driving habits and health-related quality of life in patients with age-related maculopathy.

PURPOSE: To characterize the driving habits of persons with age-related maculopathy who present to a low-vision rehabilitation clinic and to examine how driving status relates to vision-specific health-related quality of life. METHODS: The Driving Habits Questionnaire, the National Eye Institute Vision Function Questionnaire-25, and the Life Space Questionnaire were administered via telephone interview to 126 patients with age-related maculopathy who presented to a low-vision clinic during the previous year and were either past or current drivers. RESULTS: Twenty-four percent of the sample reported being a current driver. Compared with those who stopped driving, current drivers were more likely to be male, younger, have better visual acuity and higher National Eye Institute Vision Function Questionnaire-25 scores. Drivers reported driving an average of 4 days and 10 miles per week. Over 50% of drivers reported that because of their vision, they had difficulty with or did not drive at all in rain, at night, on freeways or interstate highways, in heavy traffic areas, or during rush hour. Drivers and nondrivers did not differ in their life space, the spatial extent of their excursions into their environment. CONCLUSION: Some individuals who present to a low-vision clinic with age-related maculopathy do drive, although their driving exposure is low and they report avoiding challenging on-road situations. Driving status in age-related maculopathy appears to be related to better eye visual acuity and vision-specific health-related quality of life.

Activities of Daily Living↗

PubMed2002

Impact of cataract surgery on motor vehicle crash involvement by older adults.

CONTEXT: Motor vehicle crash risk in older drivers is elevated in those with cataract, a condition that impairs vision and is present in half of adults aged 65 years or older. OBJECTIVE: To determine the impact of cataract surgery on the crash risk for older adults in the years following surgery, compared with that of older adults who have cataract but who elect to not have surgery. DESIGN, SETTING, AND PATIENTS: Prospective cohort study of 277 patients with cataract, aged 55 to 84 years at enrollment, who were recruited from 12 eye clinics in Alabama from October 1994 through March 1996, with 4 to 6 years of follow-up (to March 1999). MAIN OUTCOME MEASURE: Police-reported motor vehicle crash occurrence involving patients who elected to have surgery compared with those who did not. RESULTS: Comparing the cataract surgery group (n = 174) with the no surgery group (n = 103), the rate ratio for crash involvement was 0.47 (95% confidence interval, 0.23-0.94), adjusting for race and baseline visual acuity and contrast sensitivity. The absolute rate reduction associated with cataract surgery was 4.74 crashes per million miles of travel. CONCLUSIONS: In our sample, patients with cataract who underwent cataract surgery and intraocular lens implantation had half the rate of crash involvement during the follow-up period compared with cataract patients who did not undergo surgery. Cataract surgery thus may have a previously undocumented benefit for older driver safety, reducing subsequent crash rate.

Accidents, Traffic↗

PubMed2002

Early age-related maculopathy and self-reported visual difficulty in daily life.

PURPOSE: To determine whether early age-related maculopathy (ARM) is associated with visual difficulty in daily activities beyond the difficulty that would be expected based on normal retinal aging; to determine whether scotopic sensitivity and visual acuity are associated with visual difficulties in these older adults. STUDY DESIGN: Comparative, cross-sectional questionnaire study. SUBJECTS: Ninety-two older adults with early ARM in at least one eye as defined by one or more large (>63 microm) drusen and/or focal hyperpigmentation but no choroidal neovascularization or geographic atrophy, acuity of 20/60 or better, and a reference group of 55 older adults in the same age range without these fundus features and acuity of 20/35 or better in each eye. METHOD: Tests of visual acuity and scotopic sensitivity and a general health questionnaire were carried out. The Activities of Daily Vision Scale (ADVS) was administered to assess self-reported visual difficulties in everyday tasks and expressed on a scale of 0 (extreme difficulty) to 100 (no difficulty). Fundus photographs were taken and graded to characterize the presence and severity of ARM to determine eligibility. RESULTS: For purposes of analysis, the early ARM group was divided into those whose fellow eye (FE) was 20/60 or better and those whose FE was worse than 20/60. ADVS subscale scores were substantially lower in the early ARM group with FE worse than 20/60 (medians, 58-83) compared with the normal retinal health group (medians, 97-100). Even for those with early ARM with FE 20/60 or better, four of five subscale scores were lower (medians, 81-97), albeit slightly in some cases, than those of the reference group. For both ARM subgroups, the night driving subscale had the lowest scores of all subscales. Persons with early ARM with FE 20/60 or better were more likely to report difficulty on the night driving (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.6-11.4), near vision (OR, 5.0; 95% CI, 1.9-12.9), and glare disability (OR, 2.7; 95% CI, 1.1-6.3) subscales compared with those in normal retinal health, adjusting for age, gender, medical comorbidities, and lens density. For early ARM patients with FE worse than 20/60, there was widespread reporting of difficulty on all subscales (ORs ranging from 4.7-52.9). Poor scotopic sensitivity was highly associated with difficulty on the night driving subscale (OR, 6.6; 95% CI, 1.2-35.5) but not with any other subscale. Acuity worse than 20/25 in both eyes was significantly associated with difficulty on all ADVS subscales; when this acuity impairment was present in one eye only, associations were still significantly present on some subscales, although they were weaker. CONCLUSIONS: Persons in the early phases of ARM, even when their fellow eye has relatively good acuity, are more likely to experience difficulty in night driving, near vision tasks, and glare disability compared with those in good retinal health. Scotopic dysfunction, a functional marker of early ARM, is linked to reported night driving problems. Even when acuity impairment occurs in one eye only, patients report difficulties with day driving and near and far vision tasks.

Activities of Daily Living↗

PubMed2002

Photoreceptor degeneration and dysfunction in aging and age-related maculopathy.

The relative rate of rod and cone degeneration is a fundamental characteristic of any disorder affecting photoreceptors, including aging and age-related maculopathy (ARM). The human macula consists of a small cone-dominated fovea surrounded by a rod-dominated parafovea. In aging and early ARM, rods degenerate before cones, a decline in scotopic (rod-mediated) sensitivity is more prominent than a decline in photopic (cone-mediated) sensitivity, and the time course of dark adaptation of rods slows dramatically. The topography of rod dysfunction and loss in early ARM matches the location of pathology in the retinal pigment epithelium (RPE)/Bruch's membrane complex visible in the ocular fundus. Rod dysfunction and loss in aging and ARM may be due to retinoid deficiency at the level of the photoreceptors cause by impaired retinoid translocation across the RPE/Bruch's membrane complex, a hypothesis deserving of further investigation.

Aging↗

PubMed2002

Vision-specific health-related quality of life: content areas for nursing home residents.

Nursing home residents have a high prevalence of remediable visual impairment and blindness. Future research on the effectiveness of providing eye care to nursing home residents will need to include a vision-targeted health-related quality of life (HRQOL) instrument appropriate for this population. The purpose of this study was to identify the core content areas for such an instrument. In-depth interviews on vision-related issues were conducted with 40 residents. Interviews were audio-taped, transcribed, and coded using a standardized protocol. Binocular distance and near visual acuity were assessed using the resident's 'walking around' correction to examine whether one vision-specific HRQOL measure could address the needs of residents with 'good' and 'poor' vision. Overall 1070 vision-related comments were identified. Residents mentioned 315 problem comments that were grouped into 13 categories, including ocular symptoms (18% of comments), reading (15%), general vision (13%), psychological distress (12%), and activities of daily living (ADLs) (7%). Compared to published data on vision-specific content areas most relevant to community based persons, nursing home residents focused more on ocular symptoms and basic ADLs, with no mention of issues related to driving, home care, and finances. The majority of categories mentioned did not differ on the proportion of comments made- by those with 'good' and 'poor' visual acuity, suggesting that one vision-specific HRQOL instrument would be appropriate for residents with varying levels of visual acuity. Future work will focus on developing a vision-specific HRQOL instrument for nursing home residents.

Activities of Daily Living↗

PubMed2002

Vision, attention, and self-reported driving behaviors in community-dwelling stroke survivors.

OBJECTIVE: To elucidate the relationships among vision, attention, driving status, and self-reported driving behaviors in community-dwelling stroke survivors. DESIGN: A cross-sectional design to compare stroke survivors to older adults without stroke on visual measures, attentional measures, and self-reported driving behaviors. SETTING: Rehabilitation center at a university hospital. PARTICIPANTS: Fifty stroke survivors and 105 older adults without neurologic or visual impairment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Visual acuity, contrast sensitivity, peripheral vision, useful field of view (UFOV), Behavioral Inattention Test, and a driving habits questionnaire. RESULTS: Stroke survivors had impaired contrast sensitivity, peripheral vision, and UFOV compared with older adults in good visual and neurologic health. Driving stroke survivors typically had less attentional impairment than nondrivers. Stroke survivors who returned to driving reported difficulty in challenging driving conditions, drove less, and relied more on other people for transportation than older adults without stroke. CONCLUSIONS: These results suggest that vision and attention, both of which are important for driving, are often impaired in stroke survivors. The severity of these deficits could be an influence on driving status and driving behavior. Stroke survivors who return to driving strategically limit their driving exposure and rely on others for transportation, which suggests that they may deliberately self-regulate their driving behavior.

Activities of Daily Living↗

PubMed2002

Aging-related changes in the multifocal electroretinogram.

The multifocal electroretinogram (MERG) was recorded in the central 36 degrees-diameter field in 26 young (19-30 yr) and 20 old (60-74 yr) adults in normal retinal health according to a fundus grading scale. The mean amplitude densities of the first-order and second-order responses in this retinal region were lower for old adults compared with young. The aging-related reduction of the first-order amplitude density was greatest at the fovea and decreased as a function of eccentricity. Similarly, the amplitudes of the first negative and positive peaks of the first-order MERG waveform were reduced with age, and the pattern of reduction followed a similar eccentricity dependency. The aging-related changes in the MERG waveform may be due to slowed temporal adaptation in the aged retina.

Adult↗

PubMedDate not supplied

Timed instrumental activities of daily living tasks: relationship to cognitive function and everyday performance assessments in older adults.

BACKGROUND: We live in a world where information is presented in a time-limited fashion and successful adaptation is dependent on time-limited responses. Slowed visual-processing speed is common among older adults. Its impact on everyday task performance is not clearly understood. OBJECTIVE: The goal was to determine whether visual-processing speed, as well as memory and inductive reasoning, are independently associated with the time required by older adults to complete instrumental activities of daily living typical of everyday life. METHODS: Five timed instrumental activities of daily (TIADL) tasks were administered to 173 older adults (ages 65-90 years) along with assessments of visual-processing speed, memory, and inductive reasoning. The dependent variable was the time required to perform the task (e.g., finding a telephone number, making change, finding and reading the ingredients on a can of food, finding food items on a shelf, reading instructions on medicine container). Medical and functional comorbidities known to affect task performance were measured in order to adjust for their impact on the dependent variable. Other measures of everyday task competence (Everyday Problems Test, Observed Tasks of Daily Living, questionnaire on IADL difficulties) were also administered in order to determine to what extent existing measures of everyday performance are associated with TIADL performance. Test-retest reliability of the TIADL score was assessed in a separate sample. RESULTS: Although memory and reasoning were crudely related to the time needed to perform the TIADL tasks, only processing speed was independently associated with TIADL scores. Those older adults with slow processing speed were more likely to require longer times to complete everyday tasks. Previously developed measures of everyday task competence (e.g., Everyday Problems Test, Observed Tasks of Daily Living) based on accuracy scoring did not strongly predict TIADL performance. CONCLUSION: These results suggest a unique role for an everyday competence test that focuses on the timely completion of everyday tasks, rather than on an assessment of accuracy alone. TIADL measures may prove useful in evaluating the everyday effectiveness of cognitive interventions targeted at increasing information-processing speed.

Activities of Daily Living↗