Bonnielin K. Swenor

Difficulty with Out-Loud and Silent Reading in Glaucoma

PURPOSE We evaluated the impact of glaucoma on out-loud and silent reading. METHODS. Glaucoma patients with bilateral visual field (VF) loss and normally-sighted controls had the following parameters measured: speed reading an International Reading Speed Text (IReST) passage out loud, maximum out-loud MNRead chart reading speed, sustained (30 minutes) silent reading speed, and change in reading speed during sustained silent reading. RESULTS Glaucoma subjects read slower than controls on the IReST (147 vs. 163 words per minute [wpm], P < 0.001), MNRead (172 vs. 186 wpm, P < 0.001), and sustained silent (179 vs. 218 wpm, P < 0.001) tests. In multivariable analyses adjusting for age, race, sex, education, employment, and cognition, IReST and MNRead reading speeds were 12 wpm (6%-7%) slower among glaucoma subjects compared to controls (P < 0.01 for both), while sustained silent reading speed was 16% slower (95% confidence interval [CI] = -24 to -6%, P = 0.002). Each 5 decibel (dB) decrement in better-eye VF mean deviation was associated with 6 wpm slower IReST reading (95% CI = -9 to -3%, P < 0.001), 5 wpm slower MNRead reading (95% CI = -7 to -2%, P < 0.001), and 9% slower sustained silent reading (95% CI = -13 to -6%, P < 0.001). A reading speed decline of 0.5 wpm/min or more over the sustained silent reading period was more common among glaucoma subjects than controls (odds ratio [OR] = 2.2, 95% CI = 1.0-4.9, P < 0.05). CONCLUSIONS Reading speed is slower among glaucoma patients with bilateral VF loss, with the greatest impact present during sustained silent reading. Persons with glaucoma fatigue during silent reading, resulting in slower reading over time.

The Prevalence of Concurrent Hearing and Vision Impairment in the United States

To the Editor The prevalence of dual sensory impairment (DSI) in hearing and vision has been estimated previously using self-reported data1, non-representative population samples2, or populations outside of the US.3 These estimates may not accurately reflect the true burden of DSI in the US. We determined the prevalence of DSI using objective assessments of hearing and vision in a nationally representative sample of US adults.

The Impact of Fish and Shellfish Consumption on Age-Related Macular Degeneration

PURPOSE To determine the relationship between fish and shellfish consumption and age-related macular degeneration (AMD) status in the Salisbury Eye Evaluation (SEE) Study participants. DESIGN A cross-sectional study of dietary and ophthalmologic data. PARTICIPANTS A random sample of 2520 Salisbury, Maryland, residents aged 65 to 84 years. METHODS A food frequency questionnaire was used to estimate weekly fish/shellfish consumption for each participant. Age-related macular degeneration status was determined from fundus photographs obtained at baseline and graded by 2 masked readers for drusen size, retinal pigment epithelium abnormalities, geographic atrophy (GA), and choroidal neovascularization (CNV). The association between weekly fish/shellfish intake and risk of AMD was investigated using logistic regression while adjusting for risk factors and correlation between eyes. MAIN OUTCOME MEASURES Status of AMD. RESULTS The distribution of weekly fish/shellfish consumption was not different between specific AMD categories compared with controls (P = 0.6, 0.7, and 0.7 for large drusen, pigment abnormalities, and advanced AMD compared with controls, respectively). Those with advanced AMD (CNV or GA) were significantly less likely to consume fish/shellfish high in omega-3 fatty acids (odds ratio 0.4; confidence interval, 0.2-0.8). There was no relationship of AMD with intake of crab and oysters combined, each of which has high levels of zinc. CONCLUSIONS These data support a protective effect of fish/shellfish intake against advanced AMD.

Description and validation of a test to evaluate sustained silent reading.

PURPOSE To construct and validate a test of sustained silent reading. METHODS Standardized 7300 and 7600 word passages were written to evaluate sustained silent reading. Two hundred forty subjects validated whether comprehension questions could discriminate subjects who did and did not read the passage. To evaluate test-retest properties, 49 subjects silently read the standardized passages on separate days. Sixty glaucoma suspect controls and 64 glaucoma subjects had their out loud reading evaluated with the MNRead card and an International Reading Speed Texts (IReST) passage, and their silent reading measured using the 7300 word passage. Sustained silent reading parameters included reading speed and reading speed slope over time. RESULTS Comprehension questions distinguished individuals who had and had not read passage materials. Bland-Altman analyses of intersession sustained reading speed and reading speed slope demonstrated 95% coefficients of repeatability of 57 words per minute (wpm) and 2.76 wpm/minute. Sustained silent reading speed was less correlated with MNRead (r = 0.59) or IReST passage (r = 0.68) reading speeds than the correlation of these two measures of out loud reading speed with each other (r = 0.72). Sustained silent reading speed was more likely to differ from IReST reading speed by more than 50% in rapid silent readers (odds ratio [OR] = 29, 95% confidence interval [CI] = 10-87), and comparisons of sustained and out loud reading speeds demonstrated proportional error in Bland-Altman analyses. CONCLUSIONS Tests of out loud reading do not accurately reflect silent reading speed in individuals with normal vision or glaucoma. The described test offers a standardized way to evaluate the impact of eye disease and/or visual rehabilitation on sustained silent reading.

Longitudinal relationships among visual acuity, daily functional status, and mortality: the Salisbury Eye Evaluation Study.

IMPORTANCE Determination of the mechanisms by which visual loss increases mortality risk is important for developing interventional strategies. OBJECTIVE To evaluate the direct and indirect effects of loss of visual acuity (VA) on mortality risk through functional status changes among aging adults. DESIGN, SETTING, AND PARTICIPANTS Prospective longitudinal study of a population-based sample of 2520 noninstitutionalized adults aged 65 to 84 years from September 16, 1993, through July 26, 2003, in the greater Salisbury area of Maryland. Participants underwent reassessment 2, 6, and 8 years after baseline. Mortality status was ascertained from linkage with the National Death Index through 2009. EXPOSURES Results of VA testing and self-reported functional status based on activities of daily living (ADL) and instrumental ADL (IADL). MAIN OUTCOMES AND MEASURE Mortality. RESULTS Worse VA levels at baseline were associated with an increased the risk for mortality (hazard ratio [HR], 1.16 [95% CI, 1.04-1.28]; P < .01) through their effect on lower IADL levels at baseline. Declines in VA over time were associated with increased mortality risk (HR, 1.78 [95% CI, 1.27-2.51]; P < .001) by way of decreasing IADL levels over time. Participants experiencing the mean linear decline in VA of 1 letter on the Early Treatment Diabetic Retinopathy Study acuity chart per year are expected to have a 16% increase in mortality risk during the 8-year study exclusively through associated declines in IADL levels. CONCLUSIONS AND RELEVANCE In this longitudinal study of older adults, VA loss adversely affected IADL levels, which subsequently increased the risk for mortality. Prevention of disabling ocular conditions, treatment of correctable visual impairment, and interventions designed to prevent the effect of visual impairment on IADL declines may all reduce mortality risk in aging adults.

Longitudinal Relationships among Visual Acuity and Tasks of Everyday Life: The Salisbury Eye Evaluation Study

PURPOSE To study the relationships among visual and physical function trajectories of aging adults. METHODS The community-based random sample consists of 2520 adults who were aged 65 to 84 years in 1993 to 1995 and reassessed 2, 6, and 8 years later. Presenting and best-corrected Early Treatment Diabetic Retinopathy Study visual acuity were obtained. Activities of daily living (ADLs) and instrumental ADLs (IADLs) were evaluated through survey instruments. Growth curve models were used to simultaneously estimate health trajectories and obtain associations among the trajectories while controlling for relevant covariates. RESULTS Best-corrected acuity (logMAR) worsened by an average of 0.013 (∼1 letter) annually. ADL difficulties increased by 0.22 standard deviations (SD) and IADL difficulties increased by 0.28 SD annually. Controlling for demographic and health covariates, visual acuity rates of decline correlated with rates of increase in ADL difficulties (r = 0.15, P = 0.05) and IADL difficulties (r = 0.41, P < 0.001). Acuity loss was significantly related to increases in ADLs for men (b = 0.039, P < 0.01), but not for women (b = 0.001, P > 0.9). The direct effects of acuity loss were strongest for IADLs where a 1-unit decline in acuity (logMAR) was associated with a 0.067 SD increase in IADL difficulties (P < 0.001) at baseline, and a 1-unit acuity decline (logMAR) per year resulted in a 0.10 SD unit increase in the rate of change in IADL difficulties (P < 0.001) per year. CONCLUSIONS Over time, increases in visual acuity loss were related to increased IADL difficulties in men and women and increases in ADL difficulties for men only. The findings support the importance of maintaining vision in older adults.

Age-Related Macular Degeneration Is Associated with Less Physical Activity among US Adults: Cross-Sectional Study.

Background We have a limited understanding of the effects of age-related macular degeneration (AMD) on physical activity (PA), and we have no prevalence estimates of the daily movement patterns among Americans with AMD. Therefore, we examined the association between AMD and PA and provided estimates of the daily movement patterns of Americans with AMD. Methods Data from the 2005-2006 National Health and Nutrition Examination Survey were used, including 1,656 adults (40-85 yrs). Retinal imaging was performed to classify individuals as no AMD, early AMD, or late AMD. Participants wore an ActiGraph 7164 accelerometer for 7 days to measure PA behavior. Results 93.2% of participants with late AMD were in the least desirable group (not sufficiently active and having a negative light intensity-sedentary behavior balance). After adjustments (including age), participants with late AMD, as compared to those with no AMD, engaged in 50% less moderate-to-vigorous physical activity (MVPA) (RR = 0.50; 95% CI: 0.28-0.90). When visual acuity was entered into the model along with the other covariates, the association between late AMD and MVPA was no longer significant (RR = 0.54; 95% CI: 0.29-1.01), suggesting that visual acuity may partially mediate this relationship. Conclusions Individuals with late AMD engage in very little moderate-to-vigorous physical activity. Visually acuity, in part, explains the relationship between late AMD and PA.

Does Visual Impairment Affect Mobility Over Time? The Salisbury Eye Evaluation Study

PURPOSE To determine if the odds of mobility disability increases at a different rate among visually impaired (VI) as compared with nonvisually impaired (NVI) over an 8-year period. METHODS A total of 2520 Salisbury Eye Evaluation Study participants were followed 2, 6, and 8 years after baseline. VI was defined as best-corrected visual acuity worse than 20/40, or visual field of approximately less than 20°. Self-reported difficulty with three tasks was assessed at each visit: walking up 10 steps, walking down 10 steps, and walking 150 feet. Generalized estimating equation models included a 6-year spline, and explored differences in mobility difficulty trajectories by including an interaction between VI status and the spline terms. Odds ratios (OR) and 95% confidence intervals (CI) compared mobility difficulty for each task by VI status. RESULTS At baseline, the VI were significantly more likely to report difficulty mobility tasks than the NVI (OR(difficultywalkingup10steps) = 1.37, CI: 1.02-1.80; OR(difficultywalkingdown10steps) = 1.55, CI: 1.16-2.08; OR(difficultywalking150feet) = 1.50, CI: 1.10-2.04). The trajectory of mobility disability did not differ by VI status from baseline to the 6-year visit. However, the difference between the VI and NVI declined at the 8-year visit, which may be due to loss of VI participants at risk of developing mobility difficulty. CONCLUSIONS The VI were more likely to report mobility disability than the NVI, but the trajectory of mobility disability was not steeper among the VI as compared to the NVI over the study period.

Refractive Error and Visual Function Difficulty in a Latino Population

OBJECTIVE To assess the association of correction of myopia, hyperopia, and astigmatism with self-reported near and distance visual function. DESIGN Population based, cross-sectional study. PARTICIPANTS A random sample of 4272 Latinos older than 40 years of age from Arizona with both ophthalmic examination and questionnaire data, including answers to the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25). METHODS Cases of refractive error (RE) were defined as subjects who met at least 1 of the following criteria in both eyes: myopia, sphere -0.5 diopters (D) or less; hyperopia, sphere 1.0 D or more; or astigmatism, cylinder 0.75 D or more. Uncorrected refractive error (URE) was defined as having RE and achieving 2 lines or more of improvement in visual acuity in both eyes after refraction. The association between RE category and near and distance vision difficulty (as measured by the NEI VFQ-25 near and distance vision subscores) was modeled with ordinal logistic regression, adjusting for age, gender, diabetes, hypertension, income, education, and acculturation. MAIN OUTCOME MEASURES Association between RE correction and near and distance vision difficulty by type of RE (myopia, hyperopia, and astigmatism). RESULTS Of 4272 participants, 54% had RE. Forty-eight percent of these had myopia, 41% had hyperopia, and 11% had astigmatism. Fourteen percent of myopes, 21% of hyperopes, and 22% of astigmatics had URE. Subjects with myopia, astigmatism, and hyperopia were significantly more likely to report more distance vision difficulty than subjects without RE, regardless of whether they had correction (odds ratios [ORs], 1.7-3.7; P<0.005 for all). Subjects with corrected myopia reported less near vision difficulty than subjects without RE (OR, 0.8; 95% confidence interval [CI], 0.7-0.9). Subjects with uncorrected hyperopia and uncorrected astigmatism reported more near vision difficulty than those without RE (OR, 1.6; 95% CI, 1.2-2.2; and OR, 1.7; 95% CI, 1.0-3.0, respectively). Self-reported distance and near visual function scores were sensitive to nonvision variables, namely, age, gender, diabetes, high blood pressure, acculturation score, income, and education. CONCLUSIONS In this population, correction of any type of RE is not entirely sufficient to restore distance visual function to the level of those without RE. More research is necessary to determine the reasons for this shortcoming.

Comparing the Impact of Refractive and Nonrefractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation

PURPOSE To compare the effects of uncorrected refractive error (URE) and nonrefractive visual impairment (VI) on performance and disability measures. DESIGN Cross-sectional, population-based study. PARTICIPANTS A total of 2469 individuals with binocular presenting visual acuity (PVA) of ≥ 20/80 who participated in the first round of the Salisbury Eye Evaluation study. METHODS The URE was defined as binocular PVA of ≤ 20/30, improving to >20/30 with subjective refraction. The VI was defined as post-refraction binocular best-corrected visual acuity (BCVA) of ≤ 20/30. The visual acuity decrement due to VI was calculated as the difference between BCVA and 20/30, whereas visual acuity due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of (1) vision status (VI, URE, or normal vision) using the group with normal vision as reference and (2) a 1-line decrement in acuity due to VI or URE. MAIN OUTCOME MEASURES Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. The ADV responses were analyzed using Rasch analysis to determine visual ability. RESULTS Compared with individuals with normal vision, subjects with VI (n = 191) had significantly poorer objective and subjective visual functioning in all metrics examined (P < 0.05), whereas subjects with URE (n = 132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation, and lower ADV scores (P < 0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a 1-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared with a 1-line VA decrement due to URE. CONCLUSIONS Visual impairment is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and nonrefractive vision loss should be distinguished in studies evaluating visual disability and be understood to have differing consequences.