Visual Function in Eyes with Intermediate AMD with and without Retinal Pigment Abnormalities.

SIGNIFICANCE: In intermediate AMD, a simple, clinically feasible vision test of sensitivity to radial deformation is significantly more impaired in eyes with hyperpigmentation than in eyes with large drusen but normal retinal pigmentation, consistent with the former's increased risk of progression to advanced AMD. This ongoing longitudinal study will determine whether this vision measure is predictive of progression to advanced AMD. PURPOSE: This study aimed to determine whether simple, clinically feasible psychophysical measures distinguish between two levels of intermediate AMD that differ in their risk of progression to advanced AMD: eyes with large macular drusen and retinal pigment abnormalities versus eyes with large macular drusen without pigment abnormalities. Abnormal pigmentation in the presence of large drusen is associated with a higher risk of development of advanced AMD. METHODS: Each eye of 39 individuals with the same form of intermediate AMD in both eyes was tested monocularly on a battery of vision tests. The measures (photopic optotype contrast sensitivity, discrimination of desaturated colors, and sensitivity to radial deformation [shape discrimination hyperacuity]) were compared for both dominant and nondominant eyes. ANOVA with eye (dominant or nondominant) as a within-subject factor and retinal status (pigmentary abnormalities present or absent from the macula) as a between-subject factor was used to determine statistical significance. RESULTS: Sensitivity to radial deformation was significantly reduced in eyes with large drusen and pigment changes compared with eyes with large drusen and normal retinal pigmentation (-0.40 ± 0.04 vs. -0.61 ± 0.02, respectively; F = 13.31, P = .001). CONCLUSIONS: In the presence of large macular drusen, performance on a shape discrimination task is related to the presence versus absence of abnormal retinal pigmentation, being poorer in the higher-risk group, supportive of the measure's potential to predict progression to advanced AMD.

Simple Vision Function Tests that Distinguish Eyes with Early to Intermediate Age-related Macular Degeneration.

PURPOSE: To present and compare baseline vision findings in eyes with early age-related macular degeneration (E-AMD), intermediate AMD (I-AMD), and age-similar participants with normal aging changes to the retina (No-AMD). METHODS: Two hundred and thirty-seven eyes of 125 individuals (66.4% female, mean age 75.3 years) were tested monocularly using several simple, rapid psychophysical tests: high contrast visual acuity, low contrast visual acuity at reduced luminance, contrast sensitivity, shape discrimination hyperacuity, colour vision, reading rate, and glare recovery. Retinal status was determined using colour fundus photographs that were graded according to the Beckman Initiative for Macular Research Classification Committee scale. Logistic regression analyses with generalized estimating equations were used to assess the association between each vision variable and AMD category, while taking into account the correlation between the two eyes. RESULTS: Three vision measures (contrast sensitivity [CS], shape discrimination hyperacuity [SDH], and colour discrimination [DesatCCS]) were significantly and independently associated with intermediate AMD. Relative Risk Ratios (RRR), 95% Confidence Intervals (in parentheses), beta coefficients, and significance (p) for the I-AMD vs. No-AMD model are: CS: RRR = 6.5 (1.91-22.0), beta = 1.87, p < .01; SDH: RRR = 2.34 (1.24-4.44), beta = 0.85, p < .001; DesatCCS: RRR = 1.43 (1.22-1.68), beta = 0.36, p < .001. Performance on these measures was significantly poorer for participants with I-AMD vs. No-AMD. CONCLUSIONS: Simple screening tests distinguish eyes with intermediate AMD from eyes with less severe AMD or normal aging changes. This suggests that these vision measures may be significant predictors of which participants will go on to develop advanced AMD.

Comparison of panel D-15 tests in a large older population.

PURPOSE: To determine the frequency and type of color vision defects in a large group of randomly selected older people using two versions of the D-15 and to examine the agreement between the two tests. METHODS: The Adams desaturated D-15 test was administered under Illuminant C (MacBeth lamp, ∼ 100 lux) to a group of 865 individuals aged 58 to 102 years (mean, 75.2 ± 9.1 years). No exclusion criteria, other than the reported presence of a congenital color defect, were applied. Testing was binocular with habitual near correction. If any error was made on this test, the Farnsworth D-15 was administered under identical conditions. On both tests, a color confusion score of 30 or higher was considered failing, and for those failing the test, color defect type (blue-yellow, red-green, or nonselective) was determined using the method of Vingrys and King-Smith (1988). RESULTS: The majority (60.8%) of the people tested passed both tests. For the sample as a whole, the failure rates of the Adams desaturated D-15 and the Farnsworth D-15 were 36.2% and 20.76%, respectively. As expected, for both tests, failure rate increased markedly with age. Among those who failed both tests, 17.5% of the population, the proportion of specific agreement for red-green and blue-yellow defects was high, 88%. The vast majority of those failing either or both tests had blue-yellow defects, in agreement with previous studies. CONCLUSIONS: Blue-yellow defects were quite common among the aged, becoming increasingly prevalent with increasing age. More people failed the Adams desaturated D-15 than the Farnsworth D-15, but among those who failed, the proportion of blue-yellow defects was similar for the two tests, approximately 75%. The agreement between the two tests in identifying acquired red-green and blue-yellow errors was high.

Longitudinal increase in anisometropia in older adults.

PURPOSE: Anisometropia shows an exponential increase in prevalence with increasing age based on cross-sectional studies. The purpose of this study was to evaluate longitudinal changes in anisometropia in all refractive components in older observers and to assess the influence of early cataract development. METHODS: Refractive error was assessed at two time points separated by approximately 12 years in 118 older observers (aged 67.1 and 79.3 years at the two test times). Anisometropia defined as greater than or equal to 1.00 D was calculated for all refractive components. The subjects had intact ocular lenses in both eyes throughout the study. Lens evaluations were performed at the second test using the Lens Opacities Classification System III. RESULTS: All refractive components approximately doubled in prevalence of anisometropia. Spherical equivalent anisometropia changed from 16.1 to 32.2%. Similar changes were found for spherical error (17 to 38.1%), primary astigmatism (7.6 to 17.8%), and oblique astigmatism (14.4 to 29.7%). Many who did not have anisometropia at the first visit subsequently developed anisometropia (e.g., 26.3% for spherical error and 22.9% for oblique cylinder). The onset of anisometropia occurred at all ages within the studied age range, with no particular preference for any one age. A small number lost anisometropia over time. Individual comparisons of refractive error changes in the two eyes in combination with nuclear lens changes showed that early changes in nuclear sclerosis in the two eyes could account for a large proportion of anisometropia (~40%), but unequal hyperopic shift in the spherical component in the two eyes was the primary cause of the anisometropia. CONCLUSIONS: Anisometropia is at least 10 times more common in the elderly than in children, and anisometropia develops in all refractive components in the oldest observers. Clinicians need to be aware of this common condition that could lead to binocular vision problems and potentially cause falls in the elderly.

Association between hearing and vision impairments in older adults.

PURPOSE: To determine which, if any, vision variables are associated with moderate bilateral hearing loss in an elderly population. METHODS: Four hundred and forty-six subjects completed a hearing screening in conjunction with measurements on a variety of vision tests including high contrast acuity, low contrast acuity measured under a variety of lighting conditions, contrast sensitivity, stereopsis, and colour vision. Logistic regression analyses were used to assess the relationship between various vision variables and hearing impairment while controlling for demographic and other co-morbid conditions. RESULTS: In this sample of older adults with a mean age of 79.9 years, 5.4% of individuals were moderately visually impaired (binocular high contrast VA worse than 0.54 logMAR, Snellen equivalent 6/21 or 20/70) and 12.8% were moderately bilaterally hearing impaired (hearing none of the 40 dB tones at 500, 2000 or 4000 Hz in either ear). Three measures of low contrast acuity, but not high contrast acuity or other vision measures, were significantly associated with hearing loss when controlling for age, cataract surgery history, glaucoma history and self reported stroke, all of which were significantly associated with hearing loss, although the association of glaucoma with hearing loss was negative. CONCLUSIONS: Poorer vision for low contrast targets was associated with an increased risk of hearing impairment in older adults. Audiologists and optometrists should enquire about the other sense in cases in which a deficit is measured as individuals with dual sensory loss are at a marked disadvantage in daily life.

Non-standard vision measures predict mortality in elders: the Smith-Kettlewell Institute (SKI) study.

PURPOSE: To determine which vision tests predict mortality within 10 years in a community-based elderly sample. METHODS: Nine hundred residents of Marin County, California 58 to 101 years of age (mean 75 years at baseline), underwent a battery of tests, including high contrast acuity, low contrast acuity, low contrast/low luminance acuity, acuity in glare, contrast sensitivity, color vision, stereopsis, standard and attentional fields. The association between the vision tests and mortality within 10 years of baseline was assessed with Cox Proportional Hazards models controlling for age, sex, education level, depression, cognitive status and self-reported medical conditions. RESULTS: Forty-three percent of the sample died within 10 years of baseline. When controlling for mortality-related covariates, impairment in any of the vision measures was associated with increased risk of death. However, non-standard vision measures (ie, impairment in low contrast/low luminance acuity, standard field integrity and the impact of the attentional task on field integrity) were more highly associated with mortality than standard high contrast acuity. CONCLUSIONS: In agreement with other studies, we find that visual impairment is a significant predictor of death. However, the strongest relationship was found for measures other than high contrast acuity. These results suggest that non-standard vision measures may be more sensitive indicators of generalized aging in the most elderly.

Monocular vs. binocular measurement of spatial vision in elders.

PURPOSE: To evaluate the frequency and magnitude of binocular gain (and loss) for high-contrast acuity, various low-contrast spatial vision measures and contrast sensitivity in an elderly population. METHODS: Ninety-five individuals over the age of 70 (mean age 80.5 years, range, 71.8 to 93.5) with acuity of 20/40 (logMAR 0.3) or better in at least one eye participated. Each individual was tested binocularly and then monocularly on high-contrast acuity, various low-contrast acuity measures, and contrast sensitivity. Binocular gain for acuity measures was defined as better performance by one line or more under binocular conditions than with the better eye alone. Binocular loss was defined as poorer performance by one line or more binocularly than with the better eye alone. For contrast sensitivity, the criterion for binocular gain or loss was one letter triplet (0.15 log unit) or more difference. For each measure, the frequency of binocular gain and loss, as well as the mean gain or loss were determined. RESULTS: The mean difference between binocular and better eye monocular acuity was <2 letters for all measures, suggesting little gain or loss. However, the percent of individuals showing a line or more of gain or loss ranged from approximately 20% for high-contrast acuity to 49.5% for low-contrast acuity at low luminance. This indicates that for 1/5 to (1/2) of individuals, binocular vision is not well represented by monocular vision measures. All low contrast measures and contrast sensitivity show more binocular gain/loss than standard acuity. As has been previously reported, in the presence of large interocular differences, binocular gain is not seen, but binocular loss does not necessarily occur. CONCLUSIONS: For a significant portion of this elderly population, binocular performance is not well represented by better eye monocular measures. This indicates that to get a true sense of an individual';s vision function in daily life, one must measure vision binocularly.

Dual sensory loss: overview of problems, visual assessment, and rehabilitation.

This article provides an overview of some of the problems and possible solutions surrounding the neglected issue of combined vision and hearing deficits. The subject is treated by considering each subpopulation, ranging from those who have no residual vision or hearing to those with mild coexisting vision and hearing losses. An attempt is made to relate the different types of visual deficit to the likely problems encountered in real-life activities, such as communication and travel, among individuals who also have a hearing impairment. The assessment and appropriate referral of patients with these combined deficits is discussed, including the interpretation of visual test results and the importance of factors other than standard visual acuity. Speculation is offered on potential strategies and solutions for rehabilitation as well as the need for future research and improvements in service delivery.

Face recognition in the elderly.

PURPOSE: The purpose of this study was to assess face recognition ability in a large sample of elders (n=572, mean age=78.1 years) and to identify factors that affect performance. METHODS: Face recognition was measured by presenting standardized faces of varying sizes to simulate normal-sized faces at different viewing distances. Subjects were asked to identify the name of the person and their facial expression. Threshold equivalent viewing distance (EVD) was calculated. High- and low-contrast acuity, contrast sensitivity, low-contrast/low-luminance acuity, disability glare, stereoacuity, and visual field measures (with and without an attentional task) were also measured. These vision measures, along with demographic information (age, sex, education) and cognitive status, were included in a multiple regression analysis to determine which factors predicted task performance. RESULTS: This cross-sectional sample of elders showed significant declines in face recognition with age. Mean threshold EVD ranged from 8.0 m for participants

Night driving self-restriction: vision function and gender differences.

PURPOSE: The purpose of this study was to evaluate gender differences in the relationship between night driving self-restriction and vision function in an older population. METHODS: Night driving self-restriction patterns (assessed by questionnaire) were examined cross-sectionally in relation to age, gender, health and cognitive status, depression, and vision function in a sample of 900 elders (mean age, 76 years) living in Marin County, California. RESULTS: Of the total sample, 91% of men and 77% of women were current drivers. The mean age of the drivers was 73.3 years (range, 58-96 years). Among current drivers, women had slightly better vision function than men on most measures (low-contrast acuity, contrast sensitivity, low-contrast acuity in glare, low-contrast, low-luminance acuity, and glare recovery) but were twice as likely as men to restrict their driving to daytime. Men showed significant associations with avoidance of night driving on four spatial vision measures (high- and low-contrast acuity, low-contrast, low-luminance acuity, and contrast sensitivity). For women, in addition to these measures, a significant association was seen for low-contrast acuity in glare. Neither men nor women showed significant associations between driving restriction and performance on the other vision measures examined (glare recovery time, attentional field integrity, or stereopsis). The vision measures most predictive of self-restriction were contrast sensitivity for men and low-contrast acuity in glare for women. CONCLUSIONS: Including both cessation and self-restriction, men over age 85 years are 6.6 times more likely than women to be driving at night. For both genders, vision plays a significant role in the self-restriction decision. A higher percentage of men than women continue to drive at night with poor vision. Men's night-driving cessation was associated with contrast sensitivity and depression, whereas women's night-driving cessation was associated with low-contrast acuity in glare as well as age.

Low contrast vision function predicts subsequent acuity loss in an aged population: the SKI study.

Can vision tests predict subsequent loss of acuity? The association between performance on several low contrast spatial vision measures, glare recovery, color discrimination, flicker sensitivity, stereopsis and ocular disease status at baseline and acuity loss 4.4 years later was examined in a large aged random sample with good initial acuity. In univariate analyses, several vision measures, retinal disease status and age were each significant predictors of subsequent acuity loss. In a multiple regression analysis, only low contrast spatial vision was a significant predictor, but the other vision measures, retinal disease status and age were not. For each doubling of low contrast spatial vision threshold at baseline, individuals were more than two times as likely to suffer subsequent significant visual acuity loss. Tests of low contrast spatial vision are strong predictors of significant subsequent visual acuity loss. These findings have implications for clinical trials, clinical management, and acceptance of these measures into clinical practice.

Vision and driving self-restriction in older adults.

OBJECTIVES: To assess driving self-restriction (vision related and nonvision related) in relation to vision test performance of older adults. DESIGN: Cross-sectional study. SETTING: Population-based cohort of community-dwelling older adults. PARTICIPANTS: Six hundred twenty-nine current drivers aged 55 and older had driving behavior, health, and physical function assessed and vision function tested in 1993-95. MEASUREMENTS: Self-report of driving restriction as vision or non-vision related and performance on a comprehensive battery of vision tests (visual acuity; contrast sensitivity; effects of illumination level, contrast, and glare on acuity; visual fields with and without attentional load; color vision; temporal sensitivity; and the effect of dim light on walking ability). RESULTS: Demographic, health, and functional characteristics differed significantly between restrictors and nonrestrictors but not between vision- and nonvision-related restrictors. Controlling for potential confounding, only vision-related driving self-restriction was significantly associated with reduced performance on nonstandard measures of acuity. Poor depth perception was significantly associated with restriction for both vision- and nonvision-related reasons. Poor performance on attentional visual field tests, analyzed individually and in combination with standard field tests, was not associated with driving self-restriction. CONCLUSION: Older adults with early changes in spatial vision function and depth perception appear to recognize their limitations and restrict their driving even if they do not acknowledge the visual impairment as the cause for restriction. Poor visual attention, a risk factor for crashes, may not be recognized. Additional studies of driving self-restriction in relation to risk factors for crashes in older adults may help refine this strategy of reducing driving-related injury and death.

Development of refractive errors into old age.

PURPOSE: To evaluate refractive errors in older adults. METHODS: The distribution of refractive error components was evaluated in a sample of 569 older adults including 171 participants over the age of 80 years. The mean age was 75.2 years with a range from 59 to 106 years. Emphasis was placed on modern methods of analyzing astigmatic refractive errors, which convert cylindrical refractive errors into primary and oblique components. RESULTS: The known increase in hyperopia after maturity continues into old age. The primary negative astigmatic component increases dramatically in prevalence and amount after age 70 years, whereas the oblique component remains unchanged. Significant anisometropia is common in the oldest old, suggesting failure of emmetropization mechanisms with age. Substantial gender differences exist in refractive changes with age. CONCLUSIONS: The continuing changes in all components of refractive error into old age and the surprisingly high prevalence of large amounts of astigmatism and anisometropia emphasize the importance of regular refractive evaluations among the oldest old.