Visual impairment, uncorrected refractive error, and objectively measured balance in the United States

Perioperative Blindness in Spine Surgery: A Scoping Literature Review

Perioperative vision loss (POVL) is a devastating surgical complication that impacts both the recovery from surgery and quality of life, most commonly occurring after spine surgery. With rates of spine surgery dramatically increasing, the prevalence of POVL will increase proportionately. This scoping review aims to aggregate the literature pertinent to POVL in spine surgery and consolidate recommendations and preventative measures to reduce the risk of POVL. There are several causes of POVL, and the main contribution following spine surgery is ischemic optic neuropathy (ION). Vision loss often manifests immediately following surgery and is irreversible and severe. Diffusion weighted imaging has recently surfaced as a diagnostic tool to identify ION. There are no effective treatments; therefore, risk stratification for counseling and prevention are vital. Patients undergoing prone surgery of long duration and/or with significant expected blood loss are at greatest risk. Future research is necessary to develop effective treatments.

Factors associated with balance impairments in the community-dwelling elderly in urban China

BACKGROUND

Identification of factors relevant to balance performance impairments in the elderly population was critical for developing effective interventions and preventions. However, there have been very limited data available based on large scale studies. The present study identified factors that independently contributed to performance impairments in overall balance, domains of static balance, postural stability, and dynamic balance, and individual items.

METHODS

A total of 1984 community-dwelling Chinese elderly from urban areas of Shanghai were recruited. Information on demographic characteristic, exercise, and health status were collected with a face-to-face interview. Balance performances were assessed on site by trained investigators based on the X16 balance testing scale. To identify the effectors, ordinal logistic regression analysis was applied for overall balance, static balance, postural stability, and dynamic balance. Binary logistic regression analysis was used for 16 items.

RESULTS

The community-dwelling elderly residents were aged from 60 to 97 years old. With increases of age, risks of impairments in overall balance increased gradually (ORs from 1.26 to 3.20, all P < 0.01). In the elderly with overweight and obesity, there was higher proportion of balance impairments compared to the elderly with normal BMI (OR = 1.26, P < 0.001). Regular exercise every week was associated with reduced risks of balance impairments (ORs from 0.63 to 0.73, all P < 0.001). Presences with vision lesion (ORs from 1.28 to 1.59, all P < 0.001), moderate hearing impairment (OR = 1.54, P < 0.001), somesthesis dysfunction (ORs from 1.59 to 13.26, all P < 0.001), and cerebrovascular disease (OR = 1.45, P = 0.001) were related to increased risks of balance impairments. Likewise, age, exercise, vision, hearing, somesthesis, and cerebrovascular disease were significantly associated with static balance, postural stability, and dynamic balance. Both overweight and obesity and underweight were associated with higher proportions of dynamic balance impairments. Regular exercise was significantly related to reduced risks of impairments in 15 out of the 16 items.

CONCLUSIONS

In the elderly, age, overweight and obesity, exercise, vision, hearing, somesthesia, and cerebrovascular disease were dominant factors associated with impairments in overall balance, domains of static balance, postural stability, and dynamic balance, and most individual items.

TRIAL REGISTRATION

Not applicable.

The effects of age and postural constraints on prehension

Older adults adapt the execution of complex motor tasks to use compensatory strategies in the reaching-to-grasping (i.e., prehension) movement. The presence of postural constraints may exacerbate these compensatory strategies. Therefore, we investigated the reach-to-grasp action with different postural constraints (sitting, standing, and walking) in younger and older people and evaluated the postural stability during the reach-to-grasp action. Thirty individuals (15 younger and 15 older adults) performed the prehension under three postural tasks: sitting, standing, and walking. The reaching movement was slower in the walking task than in the other two postural tasks; however, there was no difference between the age groups. For the grasping action, the older adults presented a larger grip aperture, and the peak grip aperture occurred earlier during hand transportation in sitting and standing tasks. In the standing task, the margin of stability was smaller for older adults. In the walking task, there was no difference between the groups for the margin of stability. Also, prehension during sitting and standing tasks were similar, and both differed from walking across age groups. Finally, older adults reduced their margin of stability compared to younger adults, but only in the standing task. The margin of stability was similar between age groups during the walking task. We concluded that age affected grasping (distal component) but not reaching (proximal component), suggesting that healthy older adults have more difficulty controlling distal than proximal body segments.

The effects of age and central field loss on maintaining balance control when stepping up to a new level under time-pressure

Objective

To investigate the effects of age and central field loss on the landing mechanics and balance control when stepping up to a new level under time-pressure.

Methods

Eight older individuals with age-related macular degeneration (AMD), eight visually normal older and eight visually normal younger individuals negotiated a floor-based obstacle followed by a 'step-up to a new level' task. The task was performed under (1) no-pressure; (2) time-pressure: an intermittent tone was played that increased in frequency and participants had to complete the task before the tone ceased. Landing mechanics and balance control for the step-up task was assessed with a floor-mounted force plate on the step.

Results

Increased ground reaction forces and loading rates were observed under time-pressure for young and older visual normals but not for AMD participants. Across conditions, loading rates and ground reaction forces were higher in young normals compared to older normals and AMD participants. Young visual normals also demonstrated 35-39% shorter double support times prior to and during the step-up compared to older normals and AMD participants. All groups shortened their double support times (31-40%) and single support times (7-9%) in the time-pressure compared to no-pressure condition. Regarding balance control, the centre-of-pressure displacement and velocity in the anterior-poster direction were increased under time-pressure for young and older visual normals but not for AMD participants. The centre-of-pressure displacement and velocity in the medial-lateral direction were decreased for the AMD participants under time-pressure but not for young and older visual normals.

Conclusions

Despite walking faster, AMD participants did not adapt their landing mechanics under time-pressure (i.e., they remained more cautious), whilst older and young adults with normal vision demonstrated more forceful landing mechanics with the young being most forceful. A more controlled landing might be a safety strategy to maintain balance control during the step-up, especially in time-pressure conditions when balance control in the anterior-posterior direction is more challenged.

Physical Activity in Functionally Monocular Persons in the United States, 2003-2006

Purpose

Real-world physical activity patterns in monocular persons have not been previously characterized. This study uses a nationally representative sample to compare the physical activity levels of functionally monocular to binocularly sighted persons in the United States.

Methods

This cross-sectional study uses data from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey (NHANES) to compare differences in physical activity between functionally monocular and binocular participants. The main outcome measures were accelerometer-measured mean steps per day and mean daily minutes of moderate or vigorous physical activity (MVPA). Statistical analysis was conducted using multivariable negative binomial regression models adjusted for age.

Results

In total, 7967 NHANES participants had complete visual acuity and accelerometer data. The mean age at baseline was 44.5 years, and a majority were Caucasian (73%) and female (51%). In models adjusted for age only, functionally monocular participants (n = 172) took fewer steps (9277 with 95% confidence interval [CI], 8800-9753 vs. 10,057 with 95% CI, 9832-10,281) and engaged in similar minutes of MVPA (26.75 with 95% CI, 22.0-31.5 vs. 26.70 with 95% CI, 25.6-27.7) per day compared to binocularly sighted participants (n = 7758). In our final model, functionally monocular participants took 16% fewer steps per day (P < 0.01) and engaged in 26% fewer minutes per day of MVPA (P = 0.01). Poorer visual acuity, older age, female gender, obesity, congestive heart failure, and arthritis were also associated with a statistically significant decrease in physical activity in both models.

Conclusions

Functionally monocular persons have lower physical activity levels compared to those with binocular eyesight in the United States, even after adjusting for better-eye visual acuity.

Translational Relevance

Our translational study provides insight into the epidemiology of physical activity and its impact on population health. We quantify real-world physical activity in two at-risk populations, monocular and blind individuals.

Characteristics of the postural stability of the lower limb in different visual states of undergraduate students with moderate myopia

Objective: To explore the characteristics of lower limb postural stability in undergraduates with moderate myopia in three different visual states. Methods: Twenty male undergraduate students were recruited to complete respectively the static and dynamic postural stability tests under eyes-closed, myopia (taking off their glasses immediately) and corrected vision conditions. A three-dimensional force platform (Bertec, United States) was used to test static postural stability, which calculated the total path length of the Center of Pressure (COP), path length in the antero-posterior (A/P) and medio-lateral (M/L) directions, COP area, SampleEntropy (SampEn), and low-, medium-, and high-frequency spectrum energies. Dynamic postural stability was tested using the Y-balance test, and the Y-balance test scores were calculated. The Vicon three-dimensional motion capture system (Oxford, United Kingdom) measured the maximum flexion angles of the ankle, knee, and hip joints. The electromyography (EMG) root mean square (RMS) and integral EMG (iEMG) of the tibialis anterior and lateral gastrocnemius of the lower extremity were simultaneously measured using wireless surface electromyography (Noraxon, United States). Results: The SampEn-A/P and SampEn-M/L of corrected vision state higher than myopia and eyes-closed states, and myopia state larger than eyes-closed state (χ² = 51.631, p < .001). The original and standard scores of the anterior, postero-medial and comprehensive values of the three visual states had significant differences (F = 32.125, p < .001). The original and standard values of postero-lateral corrected vision and myopia were larger than those of eyes-closed states (F = 37.972, p < .001). The maximum flexion angles of the ankle and knee joints were in the following order: corrected vision, myopia and eyes-closed (F = 10.93, p < .001). The iEMG and RMS had significant differences in the three different states (χ² = 12.700, p < .001) in the all directions of YBT. Conclusion: Compared with corrected vision, the stability of static posture in the state of myopia was decreased, and the postural regularity was more regular. The dynamic postural stability in the state of myopia was also lower than that corrected vision, and the activation and work of ankle muscles were also increased.

Co-occurrences of fall-related factors in adults aged 60 to 85 years in the United States National Health and Nutrition Examination Survey

A broad set of factors are associated with falling (e.g., age, sex, physical activity, vision, health), but their co-occurrence is understudied. Our objectives were to quantify the number and pattern of co-occurring fall-related factors. Data were obtained from the U.S. National Health and Nutrition Examination Survey (N = 1,957, 60–85 years). Twenty fall-related factors were included (based on previous research), covering a wide range including cognitive, motor, sensory, health, and physical activity measures. The number and pattern of co-occurring fall-related factors were quantified with logistic regression and cluster analyses, respectively. Most participants (59%) had ≥4 fall-risk factors, and each additional risk factor increased the odds of reporting difficulty with falling by 1.28. The identified clusters included: (1) healthy, (2) cognitive and sensory impaired, and (3) health impaired. The mean number of co-occurring fall-related factors was 3.7, 3.8, and 7.2, for clusters 1, 2, and 3, respectively (p<0.001). These observations indicate that co-occurrence of multiple fall-risk factors was common in this national sample of U.S. older adults and the factors tended to aggregate into distinct clusters. The findings support the protective effect of physical activity on fall-risk, the association between gait speed and falls, and the detrimental effect of health-related factors on difficulty with falls (e.g., arthritis, prescription medications). Cluster analyses revealed a complex interplay between sex and BMI that may alter the role of BMI in the etiology of falls. Cluster analyses also revealed a large detrimental effect of health-related factors in cluster 3; it is important to extend current fall interventions (typically focused on balance, flexibility, strength, cognitive, fear factors) to include health-related interventions that target factors such as BMI and arthritis.

Body Balance of Children and Youths with Visual Impairment (Pilot Study)

AIM

The study was designed to assess the effects of surface instability in the response of the balance control system in children and youths with visual impairment (BL) and in normally sighted controls (NE).

MATERIALS AND METHODS

The empirical research study involved 80 individuals, aged from 6 to 20 years, with a mean age of 14.37 (±4.68), including 40 blind individuals and a randomly selected control group 40 normally sighted. Stabilometric measurements were performed with the use of the Platform CQ Stab 2P, with eyes open (EO) and closed (EC) on the solid surface, and then, the same procedure was performed on the platform covered with 1-centimetre-thick foam.

RESULTS

Statistical analyses (Wilcoxon matched-pairs test, Mann-Whitney U test) of the results identified during the trials reveal the following findings in the BL group in the EO and EC tests. The results of the foam surface test were higher and the differences were statistically significant in the BL group (sway path EO p = 0.009, EC p = 0.006; mean amplitude EC p = 0.030; mean velocity EO p = 0.009, EC p = 0.006; sway area EO p = 0.017, EC p = 0.009; and number of COP deflections along the sagittal plane EO p = 0.004). No similar correlations were observed in the NE group, except for the mean amplitude EO p = 0.033 and sway area EO p = 0.030. There was one difference between the BL and the NE group for the mean amplitude parameter, p = 0.018, in a solid surface test with open eyes. The results were higher in the BL group.

CONCLUSIONS

The present study showed no worse balance in the BL group than in the NE group but worse performance on the foam than without it. It indicates the need to develop body balance skills in blind people by improving their proprioceptive sensitivity. In everyday life and training, blind people should experience exteroceptive stimuli, different textures, and unstable surfaces as much as possible.

The Gatekeepers to Fitness: A Correspondence Study to Examine Disabling Practices Among Fitness Center Personnel

Fitness centers may be an ideal setting for physical activity, yet qualitative findings suggest social-level barriers constrain access for people with disabilities. To further test this, I employed an online message correspondence study to investigate the effect of impairment status on the responsiveness of a national sample of fitness centers to requests for services. Email requests were sent to 800 fitness centers, of which 200 were tailored to each of the four investigative conditions (i.e., control, vision loss, spinal cord injury, or being autistic). The odds of receiving a positive response were 40.5% lower for individuals with vision loss (p = .011) and 33.3% lower for individuals with spinal cord injury (p = .055), as compared with individuals without an impairment. Specifically, the odds of receiving a positive response for personal training were 58.8% lower among individuals with vision loss (p = .003) and 41.1% lower for individuals with spinal cord injury (p = .065).

Association Between Sensory Loss and Falls Among Middle-Aged and Older Chinese Population: Cross-Sectional and Longitudinal Analyses

Introduction: Previous studies have suggested that sensory loss is linked to falls. However, most of these studies were cross-sectional designed, focused on single sensory loss, and were conducted in developed countries with mixed results. The current study aims to investigate the longitudinal relationship between hearing loss (HL), vision loss (VL) and dual sensory loss (DSL) with falls among middle-aged and older Chinese population over 7 years. Methods: The data was obtained from the China Health and Retirement Longitudinal Survey (CHARLS). In total, 7,623 Chinese older adults aged over 45 were included at baseline 2011 in this study. Self-reported falls and HL/VL/DSL were accepted. Other confounding variables included age, sex, BMI, educational level, marital status, various physical disorders and lifestyles. The impact of baseline sensory status on baseline prevalence of falls and incident falls over 7 years were assessed using logistic regression analyses. A logistic mixed model was used to assess the association between time-varying sensory loss with incident falls over 7 years after adjusted with multi-confounding factors. Results: Single and dual sensory loss groups had significantly higher prevalence of falls compared to no sensory loss (NSL) group (DSL: 22.4%, HL: 17.4%, VL: 15.7%, NSL: 12.3%). Baseline HL (OR: 1.503, 95% CI: 1.240-1.820), VL (OR: 1.330, 95% CI: 1.075-1.646) and DSL (OR: 2.061, 95% CI: 1.768-2.404) were significantly associated with prevalence of falls. For longitudinal observation over 7 years, baseline HL/DSL and persistence of all types of sensory loss were associated with incidence of falls. Time-varying HL (OR: 1.203, 95% CI: 1.070-1.354) and DSL (OR: 1.479, 95% CI: 1.343-1.629) were associated with incident falls after adjusted with multi-confounders, while VL was not. Conclusion: HL and DSL are significantly associated with both onset and increased incidence of falls over 7 year's observation in middle-aged and elderly Chinese population. Persistence or amelioration of sensory loss status could exert divergent influences on incidence of falls, which should be considered in the development of falls-prevention public health policies for aging population.

Vision, Eye Disease, and the Onset of Balance Problems: The Canadian Longitudinal Study on Aging

PURPOSE

To understand the relationship between visual impairment, self-reported eye disease, and the onset of balance problems.

DESIGN

Population-based prospective cohort study.

METHODS

Baseline and 3-year follow-up data were used from the Canadian Longitudinal Study on Aging. The Comprehensive Cohort included 30,097 adults aged 45 to 85 years recruited from 11 sites across 7 provinces. Balance was measured using the 1-leg balance test. Those who could not stand on 1 leg for at least 60 seconds failed the balance test. Presenting visual acuity was measured using the Early Treatment of Diabetic Retinopathy Study chart. Participants were asked about a previous diagnosis of cataract, macular degeneration, or glaucoma. Logistic regression was used.

RESULTS

Of the 12,158 people who could stand for 60 seconds on 1 leg at baseline, 18% were unable to do the same 3 years later. For each line worse of visual acuity, there was a 15% higher odds of failing the balance test at follow-up (odds ratio [OR] = 1.15, 95% confidence interval [CI] 1.10, 1.20) after adjustment. Those with a report of a former (OR = 1.59, 95% CI 1.17, 2.16) or current cataract (OR = 1.31, 95% CI 1.01, 1.68) were more likely to fail the test at follow-up. Age-related macular degeneration and glaucoma were not associated with failure on the balance test.

CONCLUSION

These data provide longitudinal evidence that vision loss increases the odds of balance problems over a 3-year period. Efforts to prevent avoidable vision loss are needed, as are efforts to improve the balance of visually impaired people.

Importance and Severity Dependence of Physical Activity by GPS-Tracked Location in Glaucoma Patients

PURPOSE

To quantify the association of visual field (VF) damage on physical activity away-from-home, per away-from-home excursion, and at-home.

DESIGN

Prospective cohort study.

METHODS

Among 229 participants with glaucoma or suspected glaucoma, the severity of VF damage was defined as average sensitivity within the integrated VF (IVF). Participants wore accelerometers and global positioning system trackers for 7 days to measure physical activity and characterize activity location. Multivariable negative binomial regressions were used to test whether away-from-home activity per day, physical activity per away-from-home excursion, and at-home activity per day varied by the severity of VF damage.

RESULTS

Each 5-dB decrement in IVF sensitivity was associated with a lower number of away-from-home activities per day (18% less moderate and vigorous physical activity [MVPA] minutes/d, 95% confidence interval, 0.69-0.97) and physical activities per away-from-home excursion (20% less MVPA minutes/excursion, 95% confidence interval, 0.65-0.98). Similar findings were noted for other away-from-home activity measures (including active minutes/steps per day, or active minutes/steps per excursion). However, worse IVF sensitivity was not associated with measures of at-home activities (MVPA minutes/d, active minutes/d, and steps/d), time spent at or away from home, or excursions/wk (P > .1 for all).

CONCLUSIONS

Restriction of physical activity in more patients with severe glaucoma results mostly from activity restriction outside the home environment. These findings highlight the importance of maintaining a safe home environment (where activity is less restricted) and increasing confidence to perform activity, particular high-intensity activity, when leaving the home amongst patients with glaucoma.

Associations between BMI and visual impairment of 33 407 preschool children in Germany: a pooled cross-sectional study

BACKGROUND

Prevalence of overweight and obesity in Germany is increasing. High body weight can affect children's growth and development. This paper aimed to determine the association between body mass index (BMI) and visual impairment among preschool children and explore the potential role of obesity in predicting visual developmental disorder.

METHODS

Six consecutive years of data from the School Entry Examination were collected for all preschool children aged from 4 to 6 years residing in Rhine-Neckar County and the City of Heidelberg, Germany from 2013 to 2018. Univariate and multivariate regression were used to analyze the complete data, multiple imputation was used to deal with missing data.

RESULTS

Among the group with an immigrant background, children with obesity [OR = 1.20, 99% (1.02-1.42)] were more likely to have visual impairment compared to those with normal body weight (P < 0.01) after adjusting for survey year, age, and gender of children, education and occupation of parents, screen time-frequency, whether a television was in their bedroom, and quality of preschool outdoor environment.

CONCLUSION

There were significant associations between obesity and visual impairment among German preschool children with immigrant backgrounds. Strategies to support vulnerable groups were needed across all regional schools.

Vision Impairment and Participation in Cognitively Stimulating Activities: The Health ABC Study

BACKGROUND

Engagement in cognitively stimulating activities is associated with decreased rates of cognitive decline in older adults. However, most cognitively stimulating tasks require good vision, potentially affecting the ability of visually impaired adults to engage in these activities. We examined the relationship between vision and participation in cognitively stimulating activities.

METHOD

Data from the Health, Aging, and Body Composition study (1999-2005) were analyzed. Associations between visual function (visual acuity [VA], contrast sensitivity [CS], and stereo acuity [SA] impairments) and annual rates of change in number of cognitively stimulating activities (by self-report) performed at least once a month were examined.

RESULTS

Analyses included 924 participants aged 75.2 ± 2.8 years. At baseline, impaired CS (27%) and SA (29%) were associated with participation in fewer cognitive activities (β = -0.33, 95% CI = -0.63, -0.03 and β = -0.32, 95% CI = -0.61, -0.03, respectively), while VA (8%) was not (β = -0.34, 95% CI = -0.81, 0.13). In longitudinal models, groups with and without VA, CS, and SA impairments exhibited declines in monthly cognitive activities over time. Annual rates of decline were relatively higher in the VA (β = -0.16, 95% CI = -0.26, -0.05) and CS (β = -0.14, 95% CI = -0.19, -0.09) impaired groups than observed in the respective unimpaired groups (no VA: β = -0.12, 95% CI = -0.15, -0.10; no CS: β = -0.12, 95% CI = -0.15, -0.09), but did not achieve statistical significance. Stereo acuity (β = -0.13, 95% CI = -0.17, -0.09) and no SA (β = -0.13, 95% CI = -0.16, -0.10) groups had similar rates of decline.

CONCLUSIONS

Visually impaired older adults participate in fewer cognitive activities and although participation decline is similar to the non-impaired, lower overall participation indicates a need to identify cognitively stimulating activities accessible to visually impaired older adults.

Falls and Physical Activity among Cataract Patients in Vietnam

PURPOSE

To investigate the relationship between falls, physical activity, and other socio-demographic and visual factors among cataract patients in Ho Chi Minh City, Vietnam.

METHODS

A cross-sectional study was conducted between April and November 2018. Patients presenting to two hospitals with age-related unilateral or bilateral cataract, aged ≥50 years, literate, and scheduled for a first-eye cataract surgery were recruited. The International Physical Activity Questionnaires short form was used to measure physical activity. Visual disability score was self-reported using the Catquest-9SF. The number of falls in the last 12 months prior to data collection were self-reported. Visual acuity and contrast sensitivity were measured using standard protocols.

RESULTS

A total of 340 patients had complete data, the majority of whom were women (62.4%), living with a spouse (66.5%), had an education level of Grade 5 or below (68.2%), and a monthly income from medium to high (58.5%). Average age was 65.7 years. A total of 135 falls were reported in the last 12 months with 27.6% reporting ≥1 fall and 7.1% ≥2 falls. Persons with high (adjusted Prevalence Ratio (aPR) = 2.4, 95%CI = 1.2, 4.7) and low (aPR = 2.4, 95%CI = 1.2, 4.6) physical activity levels had more falls compared to those with moderate levels. Women (aPR = 1.7, 95%CI = 1.04, 2.7) and those with medium income (aPR = 2.9, 95%CI = 1.2, 6.9) were more likely to fall. Poor binocular logMAR visual acuity with habitual correction (aPR = 2.3, 95%CI = 1.1, 4.6) and poor visual disability scores (aPR = 1.4, 95%CI = 1.02, 2.0) were associated with falling.

CONCLUSION

Patients with a moderate level of physical activity were less likely to fall compared to those with low or high levels although this U-shape relationship needs to be further investigated in prospective interventional trials. Men and those with high monthly income, better visual acuity and visual disability score were also less likely to fall. Cataract patients might be advised to maintain a moderate level of physical activity while waiting for surgery. Strategies to prevent falls may also prioritise cataract surgery for women and those with lower income.

Prevalence and Consequences of Perceived Vision Difficulty in Aging Adults with HIV Infection

PURPOSE

Despite well-known ocular complications of HIV-related immune suppression, few studies have examined the prevalence and consequences of visual impairment among aging long-term survivors of HIV.

DESIGN

Retrospective cohort study.

METHODS

Aging HIV-infected (HIV+) men who have sex with men (MSM) and HIV-uninfected (HIV-) MSM controls reported their difficulty performing 6 vision-dependent tasks (difficulty defined as: no, a little, moderate, and extreme difficulty). Relationships were examined using logistic regression, regressing each outcome separately on categorical visual function responses, with missing data multiply imputed.

RESULTS

There were 634 age-matched pairs for a total sample of 1,268 MSM of 1,700 MSM with available data. The median age was 60 years old (interquartile range [IQR], 54, 66), and 23% were African American. Among HIV+ men, 95% were virally suppressed (viral load <400 copies/mL). HIV+ men were more likely to report moderate or extreme difficulty performing at least 1 task (21% for HIV+ compared to 13% for HIV-; P < .01). Participants reporting extreme vision-related difficulty performing at least 1 task had 11.2 times the odds of frailty (95% confidence interval [CI], 5.2-23.9), 2.6 times the odds of a slow gait speed (95% CI, 1.4-4.8), and 3.2 times the odds of impaired instrumental activities of daily living (95% CI: 1.6-6.3) compared to those reporting no vision-related difficulty on any task.

CONCLUSIONS

Perceived vision difficulty was more common among older HIV+ MSM than age-matched HIV- MSM controls and was associated with higher risk of depression and physical function loss among MSM.

Misperception of Visual Vertical in Peripheral Vestibular Disorders. A Systematic Review With Meta-Analysis

OBJECTIVE

The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception.

METHODS

A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method.

RESULTS

Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV.

CONCLUSION

Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.

Gait and Balance as Predictors and/or Mediators of Falls in Glaucoma

Purpose

To investigate the association between balance and gait measures with fall rates in glaucoma patients.

Methods

Balance and gait were measured for 239 participants with glaucoma or suspected glaucoma. Daily falls were evaluated over 24 months. Annual accelerometer trials captured average daily steps. Multivariable negative binomial models evaluated balance and gait associations with average daily steps and rates of falls per time or step, as well as whether balance and gait parameters mediated the association between integrated visual field (IVF) sensitivity and falls.

Results

Average age was 70.5 years (SD = 7.6), and 22% of the participants had moderate to severe visual field damage. Over the first 12 months of the follow-up, the cumulative probability of falling one or more times was 44.8%, and the cumulative probability of falling two or more times was 17.7%. Gait deficits were associated with fewer daily steps (P < 0.03), but no balance parameters were (P > 0.19). Worse balance was associated with a higher rate of falls per year and step (P < 0.03). No gait measures were associated with the rate of falls per year (P > 0.17). More time in double support and greater swing time variability were associated with higher falls per step, and higher velocity and faster cadence were associated with fewer falls per step (P < 0.05 for all). Neither gait nor balance measures mediated the relationship between visual field damage and fall rates. IVF remained an independent predictor of falls per step (rate ratio = 1.36 to 1.48; P < 0.001 to P < 0.005) in multivariable models including individual balance/gait parameters.

Conclusions

Although balance and gait measures are associated with fall rates, they do not explain why persons with greater visual field damage fall more frequently, suggesting the importance of other potential factors such as hazard perception.

Association of Visual Acuity Improvement With Uncorrected Refractive Error in Patients New to Low Vision Clinics

Importance

There is substantial socioeconomic and individual burden from uncorrected refractive error (URE) and chronic ocular disease. Understanding the association of visual acuity (VA) reduction with URE and the adults most likely to benefit from refraction may help support clinical decision-making in ophthalmologic care and maximize patient outcomes.

Objectives

To assess the magnitude of VA improvement associated with URE among adults under ophthalmic care who obtain low vision rehabilitation (LVR) services and identify the characteristics of the patients who are most likely to experience improvement.

Design, Setting, and Participants

This retrospective case series assessed patients 20 years or older who were new to the LVR clinics from August 1, 2013, to December 31, 2015, and who had habitual VA between 20/40 and counting fingers (not including) and underwent refraction. Data analysis was performed from April 4, 2018, to December 20, 2019.

Exposures

Patient demographics and clinical data, including habitual and refraction VA, refraction, and disease diagnosis. Habitual VA was categorized as mild (VA worse than 20/40 and at least 20/60), moderate (VA worse than 20/60 and better than 20/200), severe (VA 20/200 or worse and better than 20/500), and profound (VA 20/500 or worse) vision impairment (VI).

Main Outcomes and Measures

At least 2-line VA improvement and any VA improvement (≥1-line) by refraction.

Results

Among the 2923 patients new to LVR clinics, 1773 (mean [SD] age, 70 [18.2] years; 1069 [60.3%] female) were included in these analyses. The mean habitual VA was 20/100 (mean [SD], 0.67 [0.36] logMAR). At least 2-line improvement was observed in 493 patients (27.8%), and any VA improvement was seen in 1023 patients (57.7%). At least 2-line improvement was observed in 54 patients (34.8%) with corneal disorders and was more likely seen among patients aged 40 to <65 years compared with those aged 20 to <40 years (odds ratio [OR], 1.57; 95% CI, 1.02-2.41), African American patients compared with white patients (OR, 1.41; 95% CI, 1.08-1.85), or patients with moderate VI compared with mild VI (OR, 1.36; 95% CI, 1.07-1.72).

Conclusions and Relevance

The findings suggest that URE is prevalent among patients with ocular disease and accessing LVR and that refractive evaluation should be considered for patients with ocular disease and reduced VA, especially working-age adults aged 40 to <65 years, African American patients, and those with moderate VI.

Patterns of Daily Physical Activity across the Spectrum of Visual Field Damage in Glaucoma Patients

PURPOSE

To define and quantify patterns of objectively measured daily physical activity by level of visual field (VF) damage in glaucoma patients including: (1) activity fragmentation, a metric of health and physiologic decline, and (2) diurnal patterns of activity, a measure of rest and activity rhythms.

DESIGN

Prospective cohort study.

PARTICIPANTS

Older adults diagnosed with glaucoma or suspected glaucoma.

METHODS

Degree of VF damage was defined by the average VF sensitivity within the integrated VF (IVF). Each participant wore a hip accelerometer for 1 week to measure daily minute-by-minute activity for 7 consecutive days. Activity fragmentation was calculated as the reciprocal of the average activity bout duration in minutes, with higher fragmentation indicating more transient, rather than sustained, activity. Multivariate linear regression was used to test for cross-sectional associations between VF damage and activity fragmentation. Multivariate linear mixed-effects models were used to assess the associations between VF damage and accumulation of activity across 6 3-hour intervals from 5 am to 11 pm.

MAIN OUTCOME MEASURES

Activity fragmentation and amount of activity (steps) over the course of the day.

RESULTS

Each 5-dB decrement in IVF sensitivity was associated with 16.3 fewer active minutes/day (P < 0.05) and 2% higher activity fragmentation (P < 0.05), but not with the number of active bouts per day (P = 0.30). In time-of-day analyses, lower IVF sensitivity was associated with fewer steps over the 11 am to 2 pm, 2 pm to 5 pm, and 5 pm to 8 pm periods (106.6, 93.1, and 89.2 fewer steps, respectively; P < 0.05 for all), but not over other periods. The activity midpoint (the time at which half of the daily activity is completed) did not vary across level of VF damage.

CONCLUSIONS

At worse levels of VF damage, glaucoma patients demonstrate shorter, more fragmented bouts of physical activity throughout the day and lower activity levels during typical waking hours, reflecting low physiologic functioning. Further work is needed to establish the temporality of this association and whether glaucoma patients with such activity patterns are at a greater risk of adverse health outcomes associated with activity fragmentation.

The Association between Frailty and Uncorrected Refractive Error in Older Adults

Purpose: Uncorrected refractive error (URE) is the leading cause of impaired vision in older adults and has been associated with adverse health outcomes. Here, we investigate the association between URE and frailty in older adults.Methods: This is a cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) participants ≥60 years (1999-2006 cycles). URE was defined as visual acuity worse than 6/12 that can be improved with correction, and prefrailty and frailty were defined as meeting 1-2 and ≥3 of 4 components of a modified physical frailty phenotype. The 5-item phenotype (including slowness) was analyzed in a subset of participants with available data. Propensity score adjustment was used to address the imbalance of potential confounders (including age) between URE groups.Results: In this sample (n = 5,265), 6% of participants had URE (n = 373). In fully adjusted propensity score-based models, individuals with URE were more likely to be prefrail (OR = 1.4; 95% CI: 1.0-2.0) and frail (OR = 3.2; 95% CI: 1.3-7.4) than those without URE using the 4-item phenotype. For the 2,486 participants with 5-item phenotype data, individuals with URE were more likely to be frail (OR = 3.0; 95% CI: 1.2-7.5); however, the association with prefrailty was not statistically significant (OR = 1.8; 95% CI: 0.9-3.6).Conclusion: In this population-based sample, older adults with URE were more likely to be frail than those without URE, even after rigorous control for confounders, including age.

Evaluating Whether Sight Is the Most Valued Sense

Importance

Sight is often considered to be the sense most valued by the general public, but there are limited empirical data to support this. This study provides empirical evidence for frequent assertions made by practitioners, researchers, and funding agencies that sight is the most valued sense.

Objective

To determine which senses are rated most valuable by the general public and quantify attitudes toward sight and hearing loss in particular.

Design, Setting, and Participants

This cross-sectional web-based survey was conducted from March to April 2016 through a market research platform and captured a heterogeneous sample of 250 UK adults ages 22 to 80 years recruited in March 2016. The data were analyzed from October to December 2018.

Main Outcomes and Measures

Participants were first asked to rank the 5 traditional senses (sight, hearing, touch, smell, and taste) plus 3 other senses (balance, temperature, and pain) in order of most valuable (8) to least valuable (1). Next, the fear of losing sight and hearing was investigated using a time tradeoff exercise. Participants chose between 10 years without sight/hearing vs varying amounts of perfect health (from 0-10 years).

Results

Of 250 participants, 141 (56.4%) were women and the mean (SD) age was 49.5 (14.6) years. Two hundred twenty participants (88%) ranked sight as their most valuable sense (mean [SD] rating, 7.8 [0.9]; 95% CI, 7.6-7.9). Hearing was ranked second (mean [SD] rating, 6.2 [1.3]; 95% CI 6.1-6.4) and balance third (mean [SD] rating, 4.9 [1.7]; 95% CI, 4.7-5.1). All 3 were ranked above the traditional senses of touch, taste, and smell (F7 = 928.4; P < .001). The time tradeoff exercise indicated that, on average, participants preferred 4.6 years (95% CI, 4.2-5.0) of perfect health over 10 years without sight and 6.8 years (95% CI, 6.5-7.2) of perfect health over 10 years without hearing (mean difference between sight and hearing, 2.2 years; P < .001).

Conclusions and Relevance

In a cross-sectional survey of UK adults from the general public, sight was the most valued sense, followed by hearing. These results suggest that people would on average choose 4.6 years of perfect health over 10 years of life with complete sight loss, although how this generalizes to other parts of the world is unknown.

Rifle Shooting for Athletes With Vision Impairment: Does One Class Fit All?

Revised evidence-based classification criteria introduced for shooting for athletes with vision impairment (VI shooting) suggest that athletes with impaired contrast sensitivity (CS) and visual acuity (VA) should be eligible for inclusion in the sport but should all eligible athletes compete against each other in the same “class” or is more than one class necessary? Twenty-five elite VI shooting athletes took part in the study. Two measures of visual function were assessed under standardized conditions: VA (using an ETDRS logMAR letter chart, and/or a BRVT chart) and CS (using both a Pelli-Robson chart and a Mars number chart). Shooting performance, in both prone and standing events, was measured during an international VI shooting competition. Fourteen of the 25 athletes had measurable VA, and for CS, 8 athletes had measurable function with the Pelli-Robson chart and 13 with the Mars chart. The remaining athletes had function not numerically measurable by the charts and were considered to have no residual vision. There was no indication that shooting performance varied with visual function, and individuals that had residual vision had no advantage over those without vision for either prone or standing shooting. The modifications made to VI shooting, including the use of auditory tones to guide the gun barrel, appear to have successfully rendered the sport equitable for all eligible athletes. Only one class is necessary for athletes. An improved method of measuring CS in athletes with profound VI would be advantageous.

Visual, musculoskeletal and balance symptoms in individuals with visual impairment

BACKGROUND

Visual impairment is globally among the most prevalent disabilities. Research concerning the health consequences of visual deficits is challenged by confounding effects of age, because visual impairment becomes more prevalent with age. This study investigates the influence of visual deficits on visual, musculoskeletal and balance symptoms in adults with and without visual impairment, while controlling for age effects.

METHODS

Thirty-nine patients with visual impairment, aged 18-72 years, were compared to 37 age-matched controls with normal vision, allocated to two age groups: < 45 and ≥ 45 years. Self-reported symptoms were measured using the Visual, Musculoskeletal and Balance Symptoms Questionnaire and compared with demographic and optometric variables.

RESULTS

In total, patients with visual impairment reported more symptoms than age-matched normally sighted controls. Younger adults in the control group were almost free from symptoms, whereas younger adults with visual impairment reported levels of symptoms equal to older adults with visual impairment. Multiple logistic regression modelling identified use of eyeglasses, magnifying aids and presence of anisometropia to be the most influential risk factors for reporting visual, musculoskeletal and balance symptoms, with accentuated influence on balance symptoms.

CONCLUSIONS

People with visual impairments and people with age-related normal visual deficits are both predisposed to report visual, musculoskeletal and balance symptoms relative to people without visual defects or need for eye-wear correction. Age-related variations in symptoms were observed in the control groups but not in the visual impairment groups, with younger visual impairment patients reporting as many symptoms as older visual impairment patients. These findings indicate a need for a wider interdisciplinary perspective on eye care concerning people with visual impairment and people with need for habitual daily use of eye wear correction.

Ageing vision and falls: a review

Background

Falls are the leading cause of accidental injury and death among older adults. One of three adults over the age of 65 years falls annually. As the size of elderly population increases, falls become a major concern for public health and there is a pressing need to understand the causes of falls thoroughly.

Main body of the abstract

While it is well documented that visual functions such as visual acuity, contrast sensitivity, and stereo acuity are correlated with fall risks, little attention has been paid to the relationship between falls and the ability of the visual system to perceive motion in the environment. The omission of visual motion perception in the literature is a critical gap because it is an essential function in maintaining balance. In the present article, we first review existing studies regarding visual risk factors for falls and the effect of ageing vision on falls. We then present a group of phenomena such as vection and sensory reweighting that provide information on how visual motion signals are used to maintain balance.

Conclusion

We suggest that the current list of visual risk factors for falls should be elaborated by taking into account the relationship between visual motion perception and balance control.

Physical activity, visual impairment, and eye disease

Numerous studies have demonstrated physical activity is a strong factor in overall health and well-being, and a growing body of literature, reviewed herein, suggests that several eye conditions, including glaucoma, age-related macular degeneration, and diabetic retinopathy, are associated with lower activity levels. Likewise, physical activity levels are lower in persons with worse vision. Research in this area has utilized both self-reported physical activity measures as well as objective measures of activity (i.e., accelerometers), each of which have their own strengths and limitations. Putative mechanisms explaining the association of various eye conditions with physical activity are discussed. It is possible that activity restriction occurs as a downstream consequence of eye disease/visual impairment, that activity restriction causes eye disease/visual impairment, or that causality is bidirectional; evidence supporting each of these theories is put forth. An improved understanding of the relationship between physical activity and eye disease will highlight potential secondary health risks resulting from eye disease, and can help determine whether activity might serve as a readily available preventative measure to prevent specific eye conditions.

Increased postural sway during quiet stance as a risk factor for prospective falls in community-dwelling elderly individuals

Objective

fall-related injuries constitute major health risks in older individuals, and these risks are projected to increase in parallel with increasing human longevity. Impaired postural stability is a potential risk factor related to falls, although the evidence is inconclusive, partly due to the lack of prospective studies. This study aimed to investigate how objective measures of postural sway predict incident falls.

Design, setting and participants

this prospectively observational study included 1,877 community-dwelling individuals aged 70 years who participated in the Healthy Ageing Initiative between June 2012 and December 2015.

Measurements

postural sway was measured during eyes-open (EO) and eyes-closed (EC) trials using the Wii Balance Board. Functional mobility, muscle strength, objective physical activity and cognitive performance were also measured. Participants reported incident falls 6 and 12 months after the examination.

Results

during follow-up, 255 (14%) prospective fallers were identified. Division of centre of pressure (COP) sway lengths into quintiles revealed a nonlinear distribution of falls for EO trial data, but not EC trial data. After adjustment for multiple confounders, fall risk was increased by 75% for participants with COP sway lengths ≥400 mm during the EO trial (odds ratio [OR] 1.75, 95% confidence interval [CI] 1.09-2.79), and approximately doubled for sway lengths ≥920 mm during the EC trial (OR 1.90, 95% CI 1.12-3.22).

Conclusion

objective measures of postural sway independently predict incident falls in older community-dwelling men and women. Further studies are needed to evaluate whether postural sway length is of interest for the prediction of incident falls in clinical settings.

The Association of Glaucomatous Visual Field Loss and Balance

Purpose

To relate balance measures to visual field (VF) damage from glaucoma.

Methods

The OPAL kinematic system measured balance, as root mean square (RMS) sway, on 236 patients with suspect/diagnosed glaucoma. Balance was measured with feet shoulder width apart while standing on a firm/foam surface with eyes opened/closed (Instrumental Clinical Test of Sensory Integration and Balance [ICTSIB] conditions), and eyes open on a firm surface under feet together, semi-tandem, or tandem positions (standing balance conditions). Integrated VF (IVF) sensitivities were calculated by merging right and left eye 24-2 VF data.

Results

Mean age was 71 years (range, 57–93) and mean IVF sensitivity was 27.1 dB (normal = 31 dB). Lower IVF sensitivity was associated with greater RMS sway during eyes-open foam-surface testing (β = 0.23 z-score units/5 dB IVF sensitivity decrement, P = 0.001), but not during other ICTSIB conditions. Lower IVF sensitivity also was associated with greater RMS sway during feet together standing balance testing (0.10 z-score units/5 dB IVF sensitivity decrement, P = 0.049), but not during other standing balance conditions. Visual dependence of balance was lower in patients with worse IVF sensitivity (β = −21%/5 dB IVF sensitivity decrement, P < 0.001). Neither superior nor inferior IVF sensitivity consistently predicted balance measures better than measures of overall VF sensitivity.

Conclusions

Balance was worse in glaucoma patients with greater VF damage under foam surface testing (designed to inhibit proprioceptive contributions to balance) as well as feet-together firm-surface conditions when somatosensory inputs were available.

Translational Relevance

Good balance is essential to avoid unnecessary falls and patients with VF loss from glaucoma may be at higher risk of falls because of poor balance.

Individuals with severely impaired vision can learn useful orientation and mobility skills in virtual streets and can use them to improve real street safety

Virtual reality has great potential in training road safety skills to individuals with low vision but the feasibility of such training has not been demonstrated. We tested the hypotheses that low vision individuals could learn useful skills in virtual streets and could apply them to improve real street safety. Twelve participants, whose vision was too poor to use the pedestrian signals were taught by a certified orientation and mobility specialist to determine the safest time to cross the street using the visual and auditory signals made by the start of previously stopped cars at a traffic-light controlled street intersection. Four participants were trained in real streets and eight in virtual streets presented on 3 projection screens. The crossing timing of all participants was evaluated in real streets before and after training. The participants were instructed to say “GO” at the time when they felt the safest to cross the street. A safety score was derived to quantify the GO calls based on its occurrence in the pedestrian phase (when the pedestrian sign did not show DON’T WALK). Before training, > 50% of the GO calls from all participants fell in the DON’T WALK phase of the traffic cycle and thus were totally unsafe. 20% of the GO calls fell in the latter half of the pedestrian phase. These calls were unsafe because one initiated crossing this late might not have sufficient time to walk across the street. After training, 90% of the GO calls fell in the early half of the pedestrian phase. These calls were safer because one initiated crossing in the pedestrian phase and had at least half of the pedestrian phase for walking across. Similar safety changes occurred in both virtual street and real street trained participants. An ANOVA showed a significant increase of the safety scores after training and there was no difference in this safety improvement between the virtual street and real street trained participants. This study demonstrated that virtual reality-based orientation and mobility training could be as efficient as real street training in improving street safety in individuals with severely impaired vision.

Visual, Musculoskeletal, and Balance Complaints in AMD: A Follow-Up Study

Purpose. To investigate whether patients with age-related macular degeneration (AMD) run a potentially higher risk of developing visual, musculoskeletal, and balance complaints than age-matched controls with normal vision. Methods. Visual assessments, self-rated visual function, self-rated visual, musculoskeletal, and balance complaints, and perceived general health were obtained in 37 AMD patients and 18 controls, at baseline and after an average of 3.8 years later. Results. At follow-up both groups reported decreased visual acuity (VA) and visual function, but only AMD patients reported significantly increased visual, musculoskeletal, and balance complaints. Decreased VA, need for larger font size when reading, need for larger magnification, and decreased self-rated visual function were identified as risk markers for increased complaints in AMD patients. These complaints were also identified as risk markers for decreased health. For controls, decreased VA and self-reported visual function were associated with increased visual and balance complaints. Conclusions. Visual deterioration was a risk marker for increased visual, musculoskeletal, balance, and health complaints in AMD patients. Specifically, magnifying visual aids, such as CCTV, were a risk marker for increased complaints in AMD patients. This calls for early and coordinated actions to treat and prevent visual, musculoskeletal, balance, and health complaints in AMD patients.

The influence of multiple sensory impairments on functional balance and difficulty with falls among U.S. adults

OBJECTIVE

Studies have looked at the individual associations of sensory impairment on balance, but no population-based studies have examined their combined association on balance and difficulty with falls. Thus, the purpose of this study was to examine both the independent associations and combined associations of visual impairment, peripheral neuropathy, and self-reported hearing loss with the odds of reporting difficulty with falls and functional balance.

METHODS

Data from the 2003-2004 National Health and Nutrition Examination Survey were used. Vision and peripheral neuropathy were objectively measured, and hearing was self-reported. Balance testing consisted of a modified Romberg test. After exclusions, 1662 (40-85years of age) participants provided complete data on the study variables.

RESULTS

Sensory impairment was associated with perceived difficulty of falls and functional balance. Participants who presented a single sensory impairment had 29% reduced odds of having functional balance (95% CI=0.54-0.93, p=0.01) and increased odds of reporting difficulty with falls by 61% (95% CI=0.99-2.60, p=0.05). Moreover, our multisensory models showed some evidence of a dose-response relationship, in that sensory impairment of multiple sensory systems was associated with worse balance (OR =0.59, CI=0.35-1.00, p=0.05) and perceived difficulty of falls (OR =5.02, 95% CI=1.99-12.66, p=0.002) when compared to those with less sensory impairment.

CONCLUSION

Multiple sensory impairment is associated with significantly higher odds of both reporting difficulty with falls and balance dysfunction, which may lead to a subsequent fall, ultimately compromising the individual's health.

Poor Vision and Self-Reported Functional Difficulties among Recently Hospitalized Individuals in the United States

PURPOSE

Many hospitalized adults may have limited vision and as a result be at increased risk of worse functional outcomes. Here, we determine the prevalence of poor vision among recently hospitalized United States adults. Additionally, we evaluate the impact of objective vision defects on reading difficulty and external mobility outcomes (difficulty with falls and going down steps).

METHODS

Our cross-sectional study included 1,347 adult Americans aged 50 years and older, all recently hospitalized, participating in the 2001-2008 National Health and Nutrition Examination Survey (NHANES). Self-reported difficulty with reading and going down steps/stairs/curbs data were collected for all participants, while data on self-reported falling difficulty were only available for the 2001-2004 NHANES (n=631). Presenting near and distance visual acuity (VA) were measured, with poor vision defined as VA worse than 20/40.

RESULTS

Poor near and distance vision were present in 17.4% and 9.8% of individuals, respectively. Multivariable analyses showed that the odds of reading difficulty were greater with worse VA (odds ratio, OR, 1.9 per 0.3 logMAR increment in near VA, 95% confidence interval, CI, 1.6-2.4, P<0.01), as were the odds of difficulty going down steps/stairs/curbs (OR 2.4 per 0.3 logMAR increment in distance VA, 95% CI 1.9-3.1, P<0.01) and odds of falling difficulty (OR 1.6 per 0.3 logMAR increment in distance VA, 95% CI 1.1-2.4, P=0.04).

CONCLUSION

About 1 in 10 and 1 in 6 recently hospitalized older Americans had poor distance and near vision, respectively. Many of these individuals may experience trouble reading hospital documents and ambulating, and may be at increased risk of falls.

The relationship between visual function and performance in rifle shooting for athletes with vision impairment

Background

Paralympic sports provide opportunities for those who have an impairment that might otherwise be a barrier to participation in regular sporting competition. Rifle shooting represents an ideal sport for persons with vision impairment (VI) because the direction of the rifle can be guided by auditory information when vision is impaired. However, it is unknown whether those with some remaining vision when shooting with auditory guidance would be at an advantage when compared with those with no vision at all. If this were the case then it would be necessary for those with and without remaining vision to compete in separate classes of competition.

Materials and method

The associations between shooting performance and 3 measures of visual function thought important for shooting were assessed for 10 elite VI shooters currently classified as VI. A conventional audiogram was also obtained.

Results

The sample size, though small, included the majority of European VI shooters competing at this level. The relationships between visual functions and performance confirmed that individuals with residual vision had no advantage over those without vision when auditory guidance was available. Auditory function was within normal limits for age, and showed no relationship with performance.

Summary

The findings suggest that rifle-shooting athletes with VI are able to use auditory information to overcome their impairment and optimise performance. Paralympic competition should be structured in a way that ensures that all shooters who qualify to compete in VI shooting participate within the same class irrespective of their level of VI.

Sagittal balance is more than just alignment: why PJK remains an unresolved problem

BACKGROUND

The durability of adult spinal deformity surgery remains problematic. Revision rates above 20 % have been reported, with a range of causes including wound infection, nonunion and adjacent level pathology. While some of these complications have been amenable to changes in patient selection or surgical technique, Proximal Junctional Kyphosis (PJK) remains an unresolved challenge. This study examines the contributions of non-mechanical factors to the incidence of postoperative sagittal imbalance and PJK after adult deformity surgery.

METHODS

We reviewed a consecutive series of adult spinal deformity patients who required revision for PJK from 2013 to 2015 and examined in their medical records in detail.

RESULTS

Neurologic disorders were identified in 22 (76 %) of the 29 PJK cases reviewed in this series. Neurologic disorders included Parkinson's disease (1), prior stroke (5), metabolic encephalopathy (2), seizure disorder (1), cervical myelopathy (7), thoracic myelopathy (1), diabetic neuropathy (5) and other neuropathy (4). Other potential comorbidities affecting standing balance included untreated cataracts (9), glaucoma (1) and polymyositis (1). Eight patients were documented to have frequent falls, with twelve cases having a fall right before symptoms related to the PJK were noted.

CONCLUSION

PJK is an important contributing factor to the substantial and unsustainable rate of revision surgery following adult deformity correction. Multiple efforts to avoid PJK via alterations in surgical technique have been largely unsuccessful. This study suggests that non-mechanical neuromuscular co-morbidities play an important role in post-operative sagittal imbalance and PJK. Recognizing the multi-factorial etiology of PJK may lead to more successful strategies to avoid PJK and improve surgical outcomes.

Dizziness, but not falls rate, improves after routine cataract surgery: the role of refractive and spectacle changes

Purpose

To determine whether dizziness and falls rates change due to routine cataract surgery and to determine the influence of spectacle type and refractive factors.

Methods

Self‐reported dizziness and falls were determined in 287 patients (mean age of 76.5 ± 6.3 years, 55% females) before and after routine cataract surgery for the first (81, 28%), second (109, 38%) and both eyes (97, 34%). Dizziness was determined using the short‐form of the Dizziness Handicap Inventory. Six‐month falls rates were determined using self‐reported retrospective data.

Results

The number of patients with dizziness reduced significantly after cataract surgery (52% vs 38%; χ² = 19.14^,p < 0.001), but the reduction in the number of patients who fell in the 6‐months post surgery was not significant (23% vs 20%; χ² = 0.87, p = 0.35). Dizziness improved after first eye surgery (49% vs 33%, p = 0.01) and surgery on both eyes (58% vs 35%, p < 0.001), but not after second eye surgery (52% vs 45%, p = 0.68). Multivariate logistic regression analyses found significant links between post‐operative falls and change in spectacle type (increased risk if switched into multifocal spectacles). Post‐operative dizziness was associated with changes in best eye visual acuity and changes in oblique astigmatic correction.

Conclusions

Dizziness is significantly reduced by first (or both) eye cataract surgery and this is linked with improvements in best eye visual acuity, although changes in oblique astigmatic correction increased dizziness. The lack of improvement in falls rate may be associated with switching into multifocal spectacle wear after surgery.

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.

Cardiorespiratory Fitness and Vision Loss among Young and Middle-Age U.S. Adults

Purpose.

To examine the association between vision loss and cardiorespiratory fitness among young and middle-age U.S. adults.

Design.

The study had a cross-sectional design.

Setting.

The National Health and Nutrition Examination Survey 1999–2004 served as the study setting.

Subjects.

Study subjects included 3135 adults ages 20 to 49 years.

Measures.

Cardiorespiratory fitness was assessed from cardiorespiratory extrapolation using heart rate response during submaximal treadmill testing, with inadequate cardiorespiratory fitness defined as below the 60th percentile for age and gender. Visual acuity was objectively assessed for each eye.

Analysis.

Multivariable regression (linear and logistic) models were computed to examine the association between cardiorespiratory fitness and vision.

Results.

Poorer cardiorespiratory fitness (β = −3.7 mL O2/kg per minute; 95% confidence interval: −5.3 to −2.2) was observed in subjects with visual impairment after adjusting for age, gender, race/ethnicity, and comorbid illness. Participants with vision impairment, as compared with those with normal sight, had 4.4-fold higher odds of having inadequate cardiorespiratory fitness (95% confidence interval: 1.04–18.97), whereas participants with uncorrected refractive error were not more likely to demonstrate poorer cardiorespiratory fitness.

Conclusion.

Adults with visual impairment, but not adults with uncorrected refractive error, demonstrate a significant reduction in cardiorespiratory fitness and are much more likely to have inadequate fitness compared with those with normal vision. Evaluation and implementation of strategies to increase cardiorespiratory fitness among those with vision impairment, in particular, are needed.

Characterizing functional complaints in patients seeking outpatient low-vision services in the United States

PURPOSE

To characterize functional complaints of new low-vision rehabilitation patients.

DESIGN

Prospective observational study.

PARTICIPANTS

The Low Vision Rehabilitation Outcomes Study recruited 819 patients between 2008 and 2011 from 28 clinical centers in the United States.

METHODS

New patients referred for low-vision rehabilitation were asked, "What are your chief complaints about your vision?" before their appointment. Full patient statements were transcribed as free text. Two methods assessed whether statements indicated difficulty in each of 13 functional categories: (1) assessment by 2 masked clinicians reading the statement, and (2) a computerized search of the text for specific words or word fragments. Logistic regression models were used to predict the influence of age, gender, and visual acuity on the likelihood of reporting a complaint in each functional category.

MAIN OUTCOME MEASURES

Prevalence and risk factors for patient concerns within various functional categories.

RESULTS

Reading was the most common functional complaint (66.4% of patients). Other functional difficulties expressed by at least 10% of patients included driving (27.8%), using visual assistive equipment (17.5%), mobility (16.3%), performing in-home activities (15.1%), lighting and glare (11.7%), and facial recognition and social interactions (10.3%). Good agreement was noted between the masked clinician graders and the computerized algorithm for categorization of functional complaints (median κ of 0.84 across the 13 categories). Multivariate logistic regression models demonstrated that the likelihood of reading difficulties increased mildly with age (odds ratio, 1.4 per 10-year increment in age; 95% confidence interval, 1.3-1.6), but did not differ with visual acuity (P = 0.09). Additionally, men were more likely to report driving difficulties and difficulties related to lighting, whereas women were more likely to report difficulty with either in-home activities or facial recognition or social interaction (P<0.05 for all). Mobility concerns, defined as walking difficulty and out-of-home activities, showed no relationship to gender, age, or visual acuity.

CONCLUSIONS

Reading was the most commonly reported difficulty, regardless of the patient's diagnosis. Neither visual acuity nor gender were predictive of reading concerns, although, age showed a small effect. Addressing reading rehabilitation should be a cornerstone of low-vision therapy.