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.

The association between statin use and age related maculopathy.

Aims: To evaluate the association between age related maculopathy (ARM) and statin use.

Methods: A nested case-control study among patients at the Veterans Affairs Medical Center in Birmingham, Alabama, with newly diagnosed ARM (cases) between 1997 to 2001 were selected and age matched to non-ARM controls.

Results: 550 incident cases of ARM were identified and matched to 5500 controls.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

Delays in rod-mediated dark adaptation in early age-related maculopathy.

Objective: To determine whether there are disturbances in the rod-mediated kinetics of dark adaptation in early age-related maculopathy (ARM).

Design: Comparative, observational case series.

Participants: Twenty older adults with early ARM as defined by one or more large (> 63 microm) drusen, focal hyperpigmentation, or both, but no choroidal neovascularization or geographic atrophy, and 16 adults in the same age range with none of these fundus features.

Visual risk factors for crash involvement in older drivers with cataract.

Background: The Impact of Cataracts on Mobility project has previously demonstrated that older drivers with cataract have an elevated risk of motor vehicle collision.

Objective: To examine what types of visual impairment serve as a basis of the increased crash risk of older drivers with cataract.

Methods And Design: A cross-sectional analysis was performed on 274 older drivers with cataract and 103 older drivers free of cataract recruited through 12 eye care clinics for the purposes of the Impact of Cataracts on Mobility project, a prospective study on driving mobility in older adults with cataract.

Timed instrumental activities of daily living tasks: relationship to visual function in older adults.

Purpose: To identify instrumental activities of daily living (IADL) tasks whose completion time is related to visual function in older adults.

Methods: Visual function (acuity, contrast sensitivity, and useful field of view) and the time to complete 17 visual tasks of everyday life were measured in a sample of 342 older adults (mean age 71 years, range 56 to 86) recruited from eye clinics. The timed IADL (TIADL) tasks included a variety of visual activities such as reading ingredients on cans of food and instructions on medicine bottles, finding a phone number in a directory, locating items on a crowded shelf and in a drawer, and using a screwdriver.

Aging and feature search: the effect of search area.

The preattentive system involves the rapid parallel processing of visual information in the visual scene so that attention can be directed to meaningful objects and locations in the environment. This study used the feature search methodology to examine whether there are aging-related deficits in parallel-processing capabilities when older adults are required to visually search a large area of the visual field. Like young subjects, older subjects displayed flat, near-zero slopes for the Reaction Time x Set Size function when searching over a broad area (30 degrees radius) of the visual field, implying parallel processing of the visual display.

Aging and spatial localization during feature search.

Background: Previous studies indicate that older adults, like young adults, can efficiently search for a briefly presented visual target defined by a single salient feature presented amidst background distractors. However, little is known about older adults' ability to identify the spatial location of targets during this aspect of preattentive processing.

Objective: This study examined the extent to which older adults exhibit localization problems during feature search for a target with high conspicuity.

Visual risk factors for driving difficulty among older drivers.

This study sought to evaluate associations between visual function and self-reported difficulty with driving tasks. Drivers (N = 384) between the ages of 55 and 85 were selected from ophthalmology practices and optometry clinics; three out of four of the sample had cataracts and the remaining were cataract-free. Information on driving exposure and difficulty was obtained via self-report.

Scotopic sensitivity during adulthood.

Older adults typically exhibit about a half log unit loss in scotopic sensitivity that cannot be attributed to optical factors and retinal disease suggesting a neural origin. Little is understood about the developmental course of this neural deficit as to whether it first appears in late life or gradually emerges during the course of adulthood. To address this developmental issue, scotopic sensitivity was measured in 94 adults ranging in age from the 20s to the 80s.

Self-perceptions and Current Practices of High-risk Older Drivers: Implications for Driver Safety Interventions.

Many older drivers with visual problems meet the legal requirements for licensing despite having functional impairments that elevate crash risk. In a sample of visually impaired older drivers, over half believed that their vision was not likely to cause them to crash. Eighty percent acknowledged that they would feel more protected against crashing if they avoided certain driving situations.

Aging and dark adaptation.

Older adults have serious difficulty seeing under low illumination and at night, even in the absence of ocular disease. Optical changes in the aged eye, such as pupillary miosis and increased lens density, cannot account for the severity of this problem, and little is known about its neural basis. Dark adaptation functions were measured on 94 adults ranging in age from the 20s to the 80s to assess the rate of rod-mediated sensitivity recovery after exposure to a 98% bleach.

Exploratory study of incident vehicle crashes among older drivers.

Background: As the number of older adult drivers increases, distinguishing safe from unsafe older adult drivers will become an increasing public health concern. We report on the medical and functional factors associated with vehicle crashes in a cohort of Alabama drivers, 55 years old and older.

Methods: This prospective study involved 174 older adults, on whom demographic, medical, functional, and physical performance data were collected in 1991.