Inferior field loss increases rate of falls in older adults with glaucoma

Emerging strategies targeting genes and cells in glaucoma

Glaucoma comprises a heterogeneous set of eye conditions that cause progressive vision loss. Glaucoma has a complex etiology, with different genetic and non-genetic risk factors that differ across populations. Although difficult to diagnose in early stages, compromised cellular signaling, dysregulation of genes, and homeostatic imbalance are common precursors to injury and subsequent death of retinal ganglion cells (RGCs). Lowering intraocular pressure (IOP) remains the primary approach for managing glaucoma but IOP alone does not explain all glaucoma risks. Orthogonal approaches such as large-scale genetic screening, combined with studies of animal models have been instrumental in identifying genes and molecular pathways involved in glaucoma pathogenesis. Cell type dependent vulnerability among RGCs can reveal genetic basis for specific visual deficits. A growing body of knowledge and availability of modern tools to perform targeted assessments of cellular health in different animal models facilitate development of effective and timely interventions for vision rescue. This review highlights recent findings on genes, molecules, and cell types in the context of glaucoma pathophysiology and treatment.

Evaluating Diagnostic Concordance in Primary Open-Angle Glaucoma Among Academic Glaucoma Subspecialists

Objective: The study aimed to evaluate the interobserver agreement among glaucoma subspecialists in diagnosing glaucoma and to explore the causes of diagnostic discrepancies. Methods: Three experienced glaucoma subspecialists independently assessed frequency domain optical coherence tomography, fundus color photographs, and static perimetry results from 464 eyes of 275 participants, adhering to unified glaucoma diagnostic criteria. All data were collected from the Wenzhou Glaucoma Progression Study between August 2014 and June 2021. Results: The overall interobserver agreement among the three experts was poor, with a Fleiss' kappa value of 0.149. The kappa values interobserver agreement between pairs of experts ranged from 0.133 to 0.282. In 50 cases, or approximately 10.8%, the three experts reached completely different diagnoses. Agreement was more likely in cases involving larger average cup-to-disc ratios, greater vertical cup-to-disc ratios, more severe visual field defects, and thicker retinal nerve fiber layer measurements, particularly in the temporal and inferior quadrants. High myopia also negatively impacted interobserver agreement. Conclusions: Despite using unified diagnostic criteria for glaucoma, significant differences in interobserver consistency persist among glaucoma subspecialists. To improve interobserver agreement, it is recommended to provide additional training on standardized diagnostic criteria. Furthermore, for cases with inconsistent diagnoses, long-term follow-up is essential to confirm the diagnosis of glaucoma.

Treadmill-walking impairs visual function in early glaucoma and elderly controls

AIMS

Impaired vision is an additional risk factor in elderly for falls. We investigated the hypothesis that treadmill (TM) walking affects visual function in both healthy elderly and those with early-moderate visual dysfunction due to glaucoma.

METHODS

Thirty healthy controls (HC) aged 64-83 years and 18 glaucoma patients (GLA) aged 62-82 years participated in this cross-sectional study. The impact of TM-walking on visual function was assessed binocularly for (i) best-corrected visual acuity (BCVA) with and without crowding effect, (ii) contrast sensitivity (CS), and (iii) and visual field (mean deviation, VF-MD). Visual function was tested while participants were standing or during TM-walking for 2 speed conditions: (i) fast walking at their preferred speed and (ii) walking at a fixed speed of 3.5 km/h.

RESULTS

GLA, most with early-moderate VF loss, performed equally well as HC. Independent of GROUP, an impact of SPEED on visual functions was statistically evident with large statistical effect size for (i) both types of BCVA with a mean loss of 0.02-0.05 logMAR (η2 = 0.41) and (ii) VF-MD with mean loss of 1 dB (η2 = 0.70), but not for CS.

CONCLUSIONS

Here, we introduce a paradigm for the assessment of visual function during walking. We provide proof-of-concept that our approach allows for the identification of walking induced visual function loss, i.e., a deterioration of BCVA and VF-sensitivity during TM-walking in both groups. It is therefore of promise for the investigation of the relation of vision impairment and mobility, ultimately the increased frequency of falls in advanced glaucoma.

The Association between Glaucoma Severity and Hip Fractures in California Medicare Beneficiaries

PURPOSE

To examine the association between glaucoma severity and hip fractures in older adults.

DESIGN

Retrospective cross-sectional study.

SUBJECTS

California (CA) Medicare beneficiaries in 2019 with Parts A & B coverage.

METHODS

Multivariable logistic regression was used to analyze the association between glaucoma severity (mild, moderate, and severe vs. no glaucoma) and hip fracture, after adjusting for age, sex, race and ethnicity, and Charlson Comorbidity Index score. A subgroup analysis was performed only in individuals with glaucoma to examine the odds of hip fracture for those with moderate and severe glaucoma compared to those with mild glaucoma.

MAIN OUTCOME MEASURES

The variations in the odds of hip fractures for patients with and without glaucoma and for patients with moderate and severe glaucoma compared to those with mild glaucoma.

RESULTS

Of the 2 717 346 beneficiaries in the study population, 220 662 (8.1%) had glaucoma. In multivariable regression analysis, those with mild (odds ratio [OR]: 0.83; 95% confidence interval [CI]: 0.78-0.88) and moderate glaucoma (OR: 0.88; 95% CI: 0.84-0.92) had reduced odds of hip fracture compared with those with no glaucoma. There was no statistically significant association between severe vs. no glaucoma and hip fracture (OR: 0.96; 95% CI: 0.91-1.02). Among individuals with glaucoma, the odds of hip fracture were higher for those with severe glaucoma (OR: 1.17; 95% CI: 1.08-1.27), compared with those with mild glaucoma.

CONCLUSIONS

In the CA Medicare population, the presence of glaucoma was associated with decreased likelihood of hip fracture. However, in those with glaucoma, increased glaucoma severity was associated with an increased likelihood of hip fracture. Potential mediating mechanisms requiring further study include fear of falls and physical inactivity in patients with glaucoma.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Characterizing Longitudinal Changes in Fear of Falling and Quality of Life in Patients with Varying Levels of Visual Field Damage

PURPOSE

To investigate the relationship between baseline visual field (VF) severity and rates of visual field loss with changes in quality of life (QoL) and fear of falling (FoF) in adults with glaucoma.

METHODS

Prospective cohort study, including participants from the Falls In Glaucoma Study. Quality of life and FoF were assessed annually using the Glaucoma Quality of Life-15 Questionnaire, and the University of Illinois at Chicago FoF Questionnaire, respectively, with higher Rasch-analyzed scores (in logits) indicating better QoL and greater FoF. Mean deviation (MD) values of each eye were collected, with better-eye MD taken as the primary exposure. Change rates in better-eye MD, QoL, and FoF were computed using linear regression. Separate regression models were employed to explore the relationship between baseline better-eye MD and its rate of change with rates of change in QoL and FoF.

RESULTS

The mean (standard deviation) rate of change in better-eye MD was -0.08 dB/year (0.5), rate of QoL change was -0.08 logits/year (0.4), and rate of FoF change was 0.16 logits/year (0.7). At baseline, better-eye MD (per dB worse) was significantly associated with worse baseline QoL (β = -0.10 logits [95% confidence interval [CI]: -0.13, -0.08]) and greater FoF (β = 0.06 logits [95% CI: 0.01, 0.10]). Baseline better-eye MD was associated with no significant change in QoL ( -0.004 logits/year, 95% CI: -0.02, 0.01) or FoF (-0.0001 logits/year, 95% CI: -0.02, 0.02) over time. Change rates in better-eye MD showed significant associations with faster increases in FoF over time (β = 0.26 logits/year [95% CI: 0.06, 0.45]; per dB loss/year), but not with changes in QoL (P = 0.79).

CONCLUSIONS

Patients with glaucoma generally showed worsening of QoL and FoF over time, though the degree of change was modest and not related to the degree of damage at baseline. Faster rates of better-eye MD change alone were associated with faster increases in FoF. Further studies are needed to evaluate the reasons (visual and nonvisual) for changes in QoL and functionality over time and find ways in which QoL and mobility can be improved for those with VF damage.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Visual field loss and falls requiring hospitalisation: results from the eFOVID study

BACKGROUND

Visual fields are important for postural stability and ability to manoeuvre around objects.

OBJECTIVE

Examine the association between visual field loss and falls requiring hospitalisation in adults aged 50 +.

METHODS

Older adults aged 50+ with and without visual field loss were identified using a fields database obtained from a cross-section of ophthalmologists' practices in Western Australia (WA). Data were linked to the Hospital Morbidity Data Collection and WA Hospital Mortality System to identify participants who experienced falls-related hospitalisations between 1990 and 2019. A generalised linear negative binomial regression model examined the association between falls requiring hospitalisation for those with and without field loss, based on the better eye mean deviation (mild: -2 to -6 dB, moderate: -6.01 dB to -12 dB, severe < -12.01 dB) in the most contemporaneous visual field test (3 years prior or if not available, 2 years after the fall), after adjusting for potential confounders.

RESULTS

A total of 31 021 unique individuals of whom 6054 (19.5%) experienced 11 818 falls requiring hospitalisation during a median observation time of 14.1 years. Only mean deviation index of <-12.01 dB (severe) was significantly associated with an increased rate of falls requiring hospitalisations by 14% (adjusted IRR 1.14, 95% CI 1.0-1.25) compared with no field loss, after adjusting for potential confounders. Other factors included age, with those aged 80+ having an increased rate (IRR 29.16, 95% CI 21.39-39.84), other comorbid conditions (IRR 1.49, 95% CI 1.38-1.60) and diabetes (IRR 1.25, 95% CI 1.14-1.37). Previous cataract surgery was associated with a decreased rate of falls that required hospitalisations by 13% (IRR 0.87, 95% CI 0.81-0.95) compared with those who did not have cataract surgery.

CONCLUSION

The findings highlight the importance of continuous clinical monitoring of visual field loss and injury prevention strategies for older adults with visual field loss.

Global burden of fall and associated factors among individual with low vision: A systematic-review and meta-analysis

INTRODUCTION

Low vision has a significant global health problem that impacts the personal, economical, psychological, and social life of an individual. Each year around 684 000 individuals die from falls, 80% of these deaths occur are in low- and middle-income countries. The risk of falling significantly increases with visual impairment. This review aimed to determine the global pooled prevalence of fall and associated factors among individuals with low vision.

METHODS AND MATERIALS

Systematic search of published studies done on PubMed, EMBASE, MEDLINE, Cochrane, Scopus, Web of Science CINAHL and, Google Scholar. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to report the findings. Quality of studies was assessed using the modified Newcastle-Ottawa Scale (NOS). Meta-analysis was performed using a random-effects method using the STATA™ Version 14 software.

RESULT

Thirty-five (35) studies from different regions involving 175,297 participants included in this meta-analysis. The overall pooled global prevalence fall among individual with low vision was17.7% (95% CI: 16.4-18.9) whereas the highest prevalence was 35.5%; (95% CI: 28.4-42.5) in Australia and the lowest was 19.7%; (95% CI: 7.6-31.8) seen in South America. Fear of falling (OR: 0.16(95%CI 0.09-0.30), and severity of visual impairment (OR: 0.27(95%CI (0.18-0.39) increases the odds of falling.

CONCLUSION

As one cause of accidental death, the prevalence of falls among individuals with low vision is high. Fear of falling and severity of falling increases the odds of falling. Different stakeholders should give due attention and plan effective strategies to reduce the fall among this population.

The impact of visual function on staircase use performance in glaucoma

OBJECTIVES

This cross-sectional study aimed to investigate the relationship between visual function and staircase use in glaucoma.

METHODS

Overall, 181 patients with glaucoma with a best-corrected visual acuity ≥20/400 were classified into mild to moderate (mean deviation [MD] ≥ -12 dB) and advanced (MD < -12 dB) groups, according to 24-2 VF of the worse eye. Staircase use evaluation included stair descent and ascent time (SDT/SAT) and self-reported stair difficulty. Correlations between staircase use and visual function were analysed, including binocular visual acuity, integrated visual field (IVF), and binocular contrast sensitivity (CS). Linear and logistic regression adjusted by age, sex, and comorbidities inspected the effect of visual parameters on SDT/ SAT and stair difficulty.

RESULTS

Visual function best correlated with SDT among staircase use. In mild to moderate glaucoma, area under the log CS function (AULCSF) (β = -1.648, P = 0.031) was the only visual factor significant for SDT (adjusted R2 = 0.106), whereas AULCSF (β = -1.641, P = 0.048) and MD of IVFINF0-24 (β = -0.089, P = 0.013) were associated with SDT in advanced glaucoma (adjusted R2 = 0.589). The AULCSF was the only significant visual parameter related to SAT (β = -1.125, P = 0.019) and stair difficulty (adjusted odds ratio = 0.003; 95% confidence interval, 0-0.302; P = 0.013).

CONCLUSIONS

SDT provides a higher correlation with visual function than self-reported stair difficulty. Patients with impaired CS or inferior IVF defects should be advised on stair safety and referred to low-vision services.

Endpoints for clinical trials in ophthalmology

With the identification of novel targets, the number of interventional clinical trials in ophthalmology has increased. Visual acuity has for a long time been considered the gold standard endpoint for clinical trials, but in the recent years it became evident that other endpoints are required for many indications including geographic atrophy and inherited retinal disease. In glaucoma the currently available drugs were approved based on their IOP lowering capacity. Some recent findings do, however, indicate that at the same level of IOP reduction, not all drugs have the same effect on visual field progression. For neuroprotection trials in glaucoma, novel surrogate endpoints are required, which may either include functional or structural parameters or a combination of both. A number of potential surrogate endpoints for ophthalmology clinical trials have been identified, but their validation is complicated and requires solid scientific evidence. In this article we summarize candidates for clinical endpoints in ophthalmology with a focus on retinal disease and glaucoma. Functional and structural biomarkers, as well as quality of life measures are discussed, and their potential to serve as endpoints in pivotal trials is critically evaluated.

The Patients' Perspective for the Impact of Late Detection of Ocular Diseases on Quality of Life: A Cross-Sectional Study

Background

Late detection of ocular diseases negatively affects patients' quality of life (QoL), encompassing health status, psychological, financial, and social aspects. However, the early detection of eye conditions leads to rapid intervention and avoiding complications, thus preserving the QoL. This study assessed the impact of ocular diseases late detection on patients' QoL at multi-eye clinics based on questionnaire responses.

Methods

We developed an original Arabic-English questionnaire to assess the QoL of patients with ocular diseases referred from primary and secondary healthcare centers to tertiary hospitals. It covered preliminary data, patient perspectives on having lately detected ocular disease and treatment costs, and the impact of late detection on finances, social life, psychology, health status, and awareness of current initiatives. Logistic regression analysis was used to explore the associations between patient perspectives on having ocular diseases detected at a late stage and its impact on different domains. Multivariate logistic regression was applied with impact types of health status, psychological, financial, and social (dependent variables) and age, income levels, and hospital type (independent variables).

Results

Three hundred and eighty-eight responded, with 50% experiencing psychological effects, 27% health issues, 23% social impacts, and 23% financial burdens. Two hundred seventeen patients (56%) reported having ocular condition detected in late stage. Logistic regression analysis showed positive association with health status, social well-being, and financial effects (p < 0.05). Multivariate analysis revealed pronounced effects in patients ≤ 50 years, with income \< 5000 SAR, and those visiting private clinics (p < 0.05). The social impact was greater in patients visiting private hospitals. Ninety percent of all patients emphasized the importance of increasing awareness for better QoL.

Conclusion

Significant associations were found between the late detection of eye diseases and their impact on QoL. Therefore, early detection and increasing patients' awareness of ocular diseases and treatment are essential.

Five-Year Visual Field Outcomes of the HORIZON Trial

PURPOSE

To compare visual field (VF) progression between glaucoma patients receiving cataract surgery alone (CS) or with a Hydrus microstent (CS-HMS).

DESIGN

Post hoc analysis of VF data from the HORIZON multicenter randomized controlled trial.

METHODS

A total of 556 patients with glaucoma and cataract were randomized 2:1 to either CS-HMS (369) or CS (187) and followed up for 5 years. VF was performed at 6 months and then every year after surgery. We analyzed data for all participants with at least 3 reliable VFs (false positives < 15%). Average between-group difference in rate of progression (RoP) was tested using a Bayesian mixed model and a 2-sided Bayesian P value <.05 (main outcome). A multivariable model measured the effect of intraocular pressure (IOP). A survival analysis compared the probability of global VF sensitivity dropping by predefined cutoffs (2.5, 3.5, 4.5, and 5.5 dB) from baseline.

RESULTS

Data from 352 eyes in the CS-HMS arm and 165 in the CS arm were analyzed (2966 VFs). The mean RoP was -0.26 dB/y (95% credible interval -0.36, -0.16) for CS-HMS and -0.49 dB/y (95% credible interval -0.63, -0.34) for CS. This difference was significant (P = .0138). The difference in IOP only explained 17% of the effect (P < .0001). Five-year survival analysis showed an increased probability of VF worsening by 5.5 dB (P = .0170), indicating a greater proportion of fast progressors in the CS arm.

CONCLUSIONS

CS-HMS has a significant effect on VF preservation in glaucoma patients compared with CS alone, reducing the proportion of fast progressors.

Approaching rehabilitation in patients with advanced glaucoma

Vision loss from advanced glaucoma is currently irreversible and impairs functional visual ability to effectively perform everyday tasks in a number of distinct functional domains. Vision rehabilitation strategies have been demonstrated to be effective in low vision populations and should be utilized in persons with advanced glaucoma to reduce disability and improve quality of life. Initial challenges to rehabilitation include an incomplete understanding of vision rehabilitation by the physician and patient, motivation to integrate rehabilitation into the plan of care, and availability of suitable providers to deliver this care. Physicians, working with well-trained vision rehabilitation providers can maximize function in important visual domains customized to the patient based on their needs, specific complaints, severity/pattern of visual damage, and comorbidities. Potential rehabilitative strategies to be considered for reading impairment include spectacle correction, visual assistive equipment, and sensory substitution, while potential strategies to facilitate driving in those deemed safe to do so include refractive correction, lens design, building confidence, restriction of driving to safer conditions, and avoiding situations where cognitive load is high. Mobility is frequently disrupted in advanced glaucoma, and can be addressed through careful distance refraction, behavior modification, home modification, mobility aids, walking assistance (i.e., sighted guide techniques), and smartphone/wearable technologies. Visual motor complaints are best addressed through optimization of lighting/contrast, sensory substitution, IADL training, and education. Special rehabilitative concerns may arise in children, where plans must be coordinated with schools, and working adults, where patients should be aware of their rights to accommodations to facilitate specific job tasks.

Association Between Longitudinal 10-2 Central Visual Field Change and the Risk of Visual Acuity Loss in Mild-to-Moderate Glaucoma

PRCIS

Faster worsening of 10-2 visual field (VF) was associated with the development of visual acuity (VA) loss in mild-to-moderate glaucoma, suggesting longitudinal 10-2 VF change is associated with the risk of VA impairment.

PURPOSE

To examine whether longitudinal 10-2 central VF change is associated with the risk of VA loss in glaucoma.

PATIENTS AND METHODS

Primary open angle glaucoma and glaucoma suspect eyes with ≥3 years and 5 visits of 10-2 VF examinations were included. Cox proportional hazard modeling with shared frailty was used to evaluate the hazard ratio (HR) of 10-2 VF mean deviation (MD), superior hemifield mean sensitivity (hemi-MS), and inferior hemi-MS worsening rates for developing VA loss, defined as a change in logMAR VA ≥95% test-retest variability.

RESULTS

Among the 252 eyes (148 participants, mean follow-up = 5.8 y), 30 eyes (21 participants, mean follow-up = 4.9 y) developed VA loss. There was no difference in baseline VF between eyes with and without VA loss ( P > 0.05). Eyes with VA loss showed faster 10-2 VF MD worsening [-0.39 (95% CI: -0.60, -0.18) dB/y] and hemi-MS decrease (range: -0.42~-0.38 dB/y), as compared with no-VA loss eyes [10-2 VF MD change = -0.11 (-0.16, -0.07) dB/y; hemi-MS change: -0.12~-0.07 dB/y; P < 0.05]. In the multivariable model, faster 10-2 VF MD worsening [HR (95% CI) = 4.05 (1.61, 10.22), per 1 dB/y faster], superior hemi-MS decrease [HR (95% CI) = 7.07 (2.48, 20.14), per 1 dB/y faster], and inferior hemi-MS decrease [HR (95% CI) = 8.32 (1.99, 34.91), per 1 dB/y faster] were all associated with increased risk of developing VA loss ( P < 0.05).

CONCLUSIONS

Faster 10-2 VF MD and hemifield MS worsening are associated with the development of VA loss. Monitoring the longitudinal central 10-degree VF change may suggest that there is impending VA impairment in glaucoma.

Vision rehabilitation in glaucoma patients

PURPOSE OF REVIEW

Vision rehabilitation services are important but underutilized resources for patients with glaucoma. Glaucoma and its impact on vision can affect patients' abilities to read and drive, two activities of daily living that are associated with quality of life and functional independence. In this review, we provide an overview of low vision, discuss barriers to vision rehabilitation, and outline various strategies and interventions to optimize visual function and quality of life in patients with glaucoma.

RECENT FINDINGS

Studies have shown that glaucoma negatively impacts reading, driving and overall quality of life. Decreased visual acuity, visual field loss and reduced contrast sensitivity play a role. Low vision services and interventions can help patients maximize visual function and improve their quality of life. Barriers to receiving these services exist at multiple levels and an increased awareness and integration into routine ophthalmic care are needed to deliver comprehensive care.

SUMMARY

Glaucoma is one of the leading causes of low vision. Ophthalmologists who treat glaucoma often tend to focus on objective measures to monitor progression and disease severity, but the functional impact of glaucoma should also be addressed. Low vision services can benefit patients, particularly for reading and driving, and should be considered as an essential component of patient care.

Eye Movement Abnormalities in Glaucoma Patients: A Review

Glaucoma is a common condition that relies on careful clinical assessment to diagnose and determine disease progression. There is growing evidence that glaucoma is associated not only with loss of retinal ganglion cells but also with degeneration of cortical and subcortical brain structures associated with vision and eye movements. The effect of glaucoma pathophysiology on eye movements is not well understood. In this review, we examine the evidence surrounding altered eye movements in glaucoma patients compared to healthy controls, with a focus on quantitative eye tracking studies measuring saccades, fixation, and optokinetic nystagmus in a range of visual tasks. The evidence suggests that glaucoma patients have alterations in several eye movement domains. Patients exhibit longer saccade latencies, which worsen with increasing glaucoma severity. Other saccadic abnormalities include lower saccade amplitude and velocity, and difficulty inhibiting reflexive saccades. Fixation is pathologically altered in glaucoma with reduced stability. Optokinetic nystagmus measures have also been shown to be abnormal. Complex visual tasks (eg reading, driving, and navigating obstacles), integrate these eye movements and result in behavioral adaptations. The review concludes with a summary of the evidence and recommendations for future research in this emerging field.

Visual Predictors of Postural Sway in Older Adults

Purpose

Accurate perception of body position relative to the environment through visual cues provides sensory input to the control of postural stability. This study explored which vision measures are most important for control of postural sway in older adults with a range of visual characteristics.

Methods

Participants included 421 older adults (mean age = 72.6 ± 6.1), 220 with vision impairment associated with a range of eye diseases and 201 with normal vision. Participants completed a series of vision, cognitive, and physical function tests. Postural sway was measured using an electronic forceplate (HUR Labs) on a foam surface with eyes open. Linear regression analysis identified the strongest visual predictors of postural sway, controlling for potential confounding factors, including cognitive and physical function.

Results

In univariate regression models, unadjusted and adjusted for age, all of the vision tests were significantly associated with postural sway (P < 0.05), with the strongest predictor being visual motion sensitivity (standardized regression coefficient, β = 0.340; age-adjusted β = 0.253). In multiple regression models, motion sensitivity (β = 0.187), integrated binocular visual fields (β = -0.109), and age (β = 0.234) were the only significant visual predictors of sway, adjusted for confounding factors, explaining 23% of the variance in postural sway.

Conclusions

Of the vision tests, visual motion perception and binocular visual fields were most strongly associated with postural stability in older adults with and without vision impairment.

Translational Relevance

Findings provide insight into the visual contributions to postural stability in older adults and have implications for falls risk assessment.

Comparison of the Structure-Function Relationship Between Advanced Primary Open Angle Glaucoma and Normal Tension Glaucoma

PURPOSE

The aim was to investigate and compare the characteristics of visual field (VF) defects in primary open angle glaucoma (POAG) and normal-tension glaucoma (NTG) with advanced glaucomatous damage and to determine whether the structure-function relationships found in advanced glaucoma differ based on their glaucoma classification.

PATIENTS AND METHODS

Ninety-seven eyes of 97 patients (59 eyes with POAG and 38 eyes with NTG) with advanced glaucoma were included in this cross-sectional study. Scores at each test point of the 30-2 VF total deviation map were recorded, and average values at each test point were point-wise compared between the groups. Peripapillary retinal nerve fiber layer (RNFL) and macular thickness (total, RNFL, ganglion cell layer, and inner plexiform layer thickness) were measured. The structure-function relationship based on the map of Garway-Heath was determined and compared between the 2 groups.

RESULTS

At advanced stage of glaucoma, POAG eyes demonstrated more diffusely distributed VF defects, whereas NTG eyes had more severe VF defects at the superior nasal quadrant, showing increased asymmetry. Overall, peripapillary RNFL, macular ganglion cell layer, and macular inner plexiform layer thickness showed good relationships with 30-2 VF parameters in both groups. However, in total macula and macular RNFL thickness, the structure-function relationships tended to show different characteristics depending on the glaucoma classification; NTG eyes showed overall better relationships.

CONCLUSIONS

In advanced glaucoma, differences in patterns of VF damage were found between POAG and NTG eyes. Conventional peripapillary RNFL and macular measurements showed generally good performance for estimating functional status, particularly in NTG eyes.

Perceptual Grouping During Binocular Rivalry in Mild Glaucoma

Purpose

This study tested perceptual grouping during binocular rivalry to probe the strength of neural connectivity of the visual cortex involved in early visual processing in patients with mild glaucoma.

Methods

Seventeen patients with mild glaucoma with no significant visual field defects and 14 healthy controls participated. Rivalry stimuli were 1.8°-diameter discs, containing horizontal or vertical sine-wave gratings, viewed dichoptically. To test the grouping, two spatially separated identical stimuli were presented eccentrically to the same or different eyes and to the same or different hemifields. The outcome measures were the time of exclusive dominance of the grouped percept (i.e., percept with synchronized orientations), the rivalry rate, and the epochs of exclusive dominance.

Results

For both groups, the grouping occurred primarily for the matching orientations in the same eye/same hemifield (MO SE/SH) and for the matching orientations in the same eye/different hemifield (MO SE/DH) conditions. Time dominance of the grouped percept of the glaucoma group was similar to that of the control group in all conditions. The rivalry rates in the MO SE/SH and MO SE/DH conditions were significantly larger in the control group than in the glaucoma group. The epochs of exclusive dominance of the grouped percept in the MO SE/SH condition were a median of 48-ms longer for the control group, but a median of 116-ms shorter for the glaucoma group when compared to those in the MO SE/DH condition.

Conclusion

Patients with mild glaucoma show clear impairments in binocular rivalry while evidence for deficits in perceptual grouping could be inferred only indirectly. If these deficits truly exist, they may have implications for higher levels of visual processing, such as object recognition and scene segmentation, but these predictions remain to be tested in future studies.

Visual Field Progression in Patients with Primary Open Angle Glaucoma, Normal Tension Glaucoma, and Primary Angle Closure Glaucoma

Purpose: We compared visual field progression among patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and primary angle-closure glaucoma (PACG).Methods: A total of 115 POAG, 123 NTG, and 92 PACG eyes were retrospectively analyzed. Global VF progression was evaluated by calculating the changes of mean deviations. To examine local VF deterioration, scotoma enlargement and deepening were analyzed in the superior, and inferior arcuate, and the central, zones.Results: The mean global rate of change in POAG eyes was -0.52 ± 0.74 dB/year, and -0.35 ± 0.41, and -0.38 ± 0.45 dB/year in NTG and PACG eyes; POAG eyes showed significantly more rapid progression than NTG and PACG eyes (p < 0.01). The superior arcuate zone of POAG eyes, the central zone of NTG eyes, and the inferior arcuate zone of PACG eyes exhibited more scotoma enlargement and scotoma deepening than did other zones.Conclusions: The superior arcuate zone of POAG eyes, the central zone of NTG eyes, and the inferior arcuate zone of PACG eyes showed greater VF progression.

Demographic, Clinical, and Psychosocial Predictors of Change in Medication Adherence in the Support, Educate, Empower Program

PURPOSE

To investigate whether demographic, clinical, or psychosocial factors act as moderators of change in medication adherence in the Support, Educate, Empower (SEE) program.

DESIGN

Prospective, single-arm pilot study with a pre-post design.

PARTICIPANTS

Patients with glaucoma aged ≥ 40 years and taking ≥ 1 glaucoma medication were recruited from the University of Michigan Kellogg Eye Center. Those who had electronically measured adherence ≤ 80% in the 3-month eligibility monitoring period were enrolled in the SEE program.

METHODS

Medication adherence was monitored electronically during the 7-month intervention and calculated as the percentage of doses taken correctly. Change in adherence at different points in the SEE program and cumulative change in adherence were modeled with linear regression, and baseline demographic, clinical, and psychosocial factors were investigated for significant associations.

MAIN OUTCOME MEASURES

Demographic, clinical, and psychosocial variables associated with change in medication adherence in the SEE program.

RESULTS

Thirty-nine participants completed the SEE program. These participants were on average 63.9 years old (standard deviation [SD], 10.7 years), 56% (n = 22) were male, 44% (n = 17) were White, and 49% (n = 19) were Black. Medication adherence improved from an average of 59.9% (SD, 18.5%) at baseline to 83.6% (SD, 17.5%) after the final SEE session, for an increase of 23.7% (SD, 17.5%). Although participants with lower income (< $25 000 and $25 000-50 000 vs. >$50 000) had lower baseline adherence (48.4% and 64.1% vs. 70.4%), these individuals had greater increases in adherence during the first month of medication reminders (19.6% and 21.6% vs. 10.2%; P = 0.05 and P = 0.007, respectively). Participants taking fewer glaucoma medications also had significantly greater increases in adherence with medication reminders (P < 0.001). Those with higher levels of glaucoma-related distress (GD) had lower baseline adherence and greater increases in adherence with glaucoma coaching (P = 0.06).

CONCLUSIONS

Patient-level factors associated with relatively greater improvements in medication adherence through the SEE Program included lower income, fewer glaucoma medications, and increased GD. These findings demonstrate that the SEE program can improve glaucoma self-management even among participants with social and psychological barriers to medication adherence.

Sensory integration abilities for balance in glaucoma, a preliminary study

The goal of this study was to quantify the association between sensory integration abilities relevant for standing balance and disease stage in glaucoma. The disease stage was assessed using both functional (visual field deficit) and structural (retinal nerve fiber layer thickness) deficits in the better and worse eye. Balance was assessed using an adapted version of the well-established Sensory Organization Test (SOT). Eleven subjects diagnosed with mild to moderate glaucoma stood for 3 min in 6 sensory challenging postural conditions. Balance was assessed using sway magnitude and sway speed computed based on center-of-pressure data. Mixed linear regression analyses were used to investigate the associations between glaucoma severity and balance measures. Findings revealed that the visual field deficit severity in the better eye was associated with increased standing sway speed. This finding was confirmed in eyes open and closed conditions. Balance was not affected by the extent of the visual field deficit in the worse eye. Similarly, structural damage in either eye was not associated with the balance measures. In summary, this study found that postural control performance was associated with visual field deficit severity. The fact that this was found during eyes closed as well suggests that reduced postural control in glaucoma is not entirely attributed to impaired peripheral visual inputs. A larger study is needed to further investigate potential interactions between visual changes and central processing changes contributing to reduced balance function and increased incidence of falls in adults with glaucoma.

Environmental Features Contributing to Falls in Persons With Vision Impairment: The Role of Home Lighting and Home Hazards

PURPOSE

To evaluate whether home hazards and lighting levels are associated with higher fall rates in adults with varying degrees of visual field (VF) damage from glaucoma.

METHODS

Participants with diagnosed or suspected glaucoma provided three years of prospective falls data via monthly falls diaries. A post-fall telephone questionnaire determined fall locations. Seven home areas were evaluated for hazards and lighting via an in-home assessment. Multivariate models adjusting for relevant confounders, including age, sex, comorbidity, and severity of VF damage, evaluated the influence of hazards and lighting on fall rates in each home region.

RESULTS

Mean baseline age for the 170 participants was 71.0 (7.6) years and 78 (46%) of participants were female. Fifty-nine participants experienced a total of 83 home falls, with the greatest number of falls occurring on the indoor stairs (n = 24, 29%) and bedroom (n = 17, 21%). Neither the number nor the percentage of hazardous items graded as hazardous was associated with the rate of falls (P > .26). Each 10-fold increase in room lighting was associated with 35% fewer falls in that home region (P = .02). The relation between lighting and the rate of falls did not differ with the degree of visual field damage (P > .3), and a lower fall rate was noted with better lighting even in participants with mild or no VF damage (rate ratio = 0.52/10-fold better lighting; P = 0.01).

CONCLUSIONS

Fewer home falls were found with better lighting, but not with fewer home hazards. Lighting improvements at home may reduce fall rates in older adults. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Prevalence of Falls in Patients Presenting to an Ophthalmic Outpatients Department- A Surveillance Study

Introduction:

Approximately 1 in 3 adults aged 65 and over experience a fall each year. Poor vision is an identified risk factor. The aim of this cross-sectional public health surveillance audit was to determine the prevalence of falls experienced in the previous 12 months by adult patients presenting to an ophthalmology department.

Methods:

A short questionnaire was given to consecutive patients attending an ophthalmology department at two trusts in the North West to determine whether they had experienced a fall in the previous 12 months, whether they had suffered a fracture, their eye condition and the type of glasses worn.

Results:

Data was collected for 585 patients (mean age: 69 years, SD: 13.8). Falls in the previous 12 months were reported by 96 (16.4%) patients, and a significant proportion of these were aged 60 years and over (82%, p < 0.0001, one-sample binomial test). Half of the respondents were unaware of their eye health condition for which they were attending the department. Glaucoma was the most prevalent condition in those who had experienced a fall (43%). A significant proportion of the individuals who reported a fall wore single-vision glasses (43%, p < 0.0001, one-sample chi-square test).

Conclusion:

In an ophthalmology outpatient department, the proportion of older adults who experienced a fall in the previous 12 months was lower than the reported prevalence in the general population. There is a need for health literacy to educate patients about their eye condition, the potential effects on their visual function and, consequently, managing falls risk.

Multifocal Spectacle and Monovision Treatment of Presbyopia and Falls in the Elderly

Presbyopia is an age-related condition that affects approximately 1.8 billion people worldwide. Strategies to correct presbyopia include both nonsurgical and surgical approaches. Although eye care providers assume that multifocal spectacles and monovision have lower risks than surgical interventions, there is evidence to suggest that the use of these nonsurgical approaches in the older population increases the risk for trips and falls. Each year, fall-related injuries and deaths are reported in a substantial portion of the population, both globally and in the United States. Previous studies have shown a link between visual acuity, contrast sensitivity, stereoacuity, and visual field impairments and falls. More recent mechanistic and epidemiological studies have shown that multifocal spectacles and monovision can increase the risk for falls as well. Although evidence on the financial burden of falls related to multifocal spectacles or monovision is limited, total direct medical costs related to falls associated with multifocal spectacles are estimated to be approximately $11 billion annually in the United States. Therefore, it is important that eye care providers consider the risk for falls associated with multifocal spectacles and monovision when making decisions on the best strategy for correcting presbyopia in older adults. [J Refract Surg. 2021;37(6 Suppl):S12-S16.].

Do visual fields need to be considered in classification criteria within visually impaired shooting?

Classification within the sport of vision impairment (VI) shooting is based upon the athlete's visual function. This study aimed to determine whether more than one class of competition is needed within VI shooting on the basis of visual field loss. Qualification scores of 23 elite athletes were obtained at World Championship events in prone and standing shooting disciplines. Visual field data were obtained from classification data and from assessment at events. A standardized scoring protocol determined whether athletes had function (≥10 dB) or no function (<10 dB) at locations between 0-60 degrees eccentricity along 10 meridia. Visual field function was not associated with shooting performance in prone or standing disciplines (p > 0.05). Having measurable visual field function beyond 30 degrees made no difference to athletes' ability to shoot competitively in prone (p = 0.65) or standing disciplines (p = 0.47), although a potential impact on qualification was observed in the standing discipline. There was no evidence that loss of visual field function at any specific location adversely affected ability to shoot competitively. There is currently no evidence to consider visual fields in classification within prone or standing VI shooting, although further research is needed as the sport grows.

A Review of Studies of the Association of Vision-Related Quality of Life with Measures of Visual Function and Structure in Patients with Glaucoma in the United States

Purpose: To investigate the association of quality of life (QoL) with ocular structure and function in glaucoma patients, and to identify which aspects of QoL are most closely tied to Visual Field (VF) and Visual Acuity (VA).Methods: We conducted a comprehensive review of studies on QoL in glaucoma patients using PubMed, Web of Science, and Google Scholar (from 1 January 1997 to 7 December 2019). A total of 21 studies in the United States that used the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ) or 51-item NEI VFQ were included. A descriptive analysis of data from the selected studies was conducted. The association between QoL scores and visual function and structure was investigated by ranking the strength of association on a scale from 1 (weakest) to 12 (strongest).Results: Studies reported correlations between QoL scores and Visual Structure. Associations were also reported between QoL and Visual Function both cross-sectionally and longitudinally, with a stronger association of VF and VA with distance activities (average ranking 9.1 and 9.6), vision-specific dependency (8.7 and 8.9), and driving (8.6 and 9.7). Vision-specific mental health (6.5 and 4.9), vision-specific social functioning (8.4 and 6.2), and vision-specific role difficulties (7.1 and 6.6) domains were more associated with VF than with VA.Conclusion: Our study was the first to quantify and rank the strength of association between visual function and QoL domains. Driving and psycho-social QoL domains tended to be most affected by glaucoma-related deterioration of visual function. QoL scores could be used for more patient-centered disease management.

Characterizing Longitudinal Changes in Physical Activity and Fear of Falling after Falls in Glaucoma

BACKGROUND

Older adults with visual impairments experience a higher risk of falling, and are more vulnerable to adverse health consequences associated with falls than those with normal vision. This study characterizes longitudinal changes in objectively measured physical activity and fear of falling (FoF) occurring after various types of falls in visually impaired older adults.

DESIGN

Prospective cohort study.

SETTING

Hospital-based enrollment.

PARTICIPANTS

People with glaucoma or suspected glaucoma.

MEASUREMENTS

Falls were defined as unintentionally coming to rest on the ground or a lower level, and injurious falls were determined though follow-up calls. Study participants were categorized into three groups-fallers with injurious consequences, fallers without injurious consequences, and non-fallers based on fall status in the first year. Physical activity was assessed by waist-bound accelerometer. FoF was evaluated by questionnaire, with Rasch modeling generating FoF scores where higher scores reflected worse FoF. The 3-year longitudinal changes of physical activity and FoF were modeled using mixed-effects models.

RESULTS

In linear models fully adjusted for visual field damage and other covariates, physical activity among injurious fallers showed greater annual (per year) declines in daily steps (-425 steps/d, 95% confidence interval (CI) = -793, -57), daily active minutes (-13 min/d, 95% CI = -21, -6), and daily moderate and vigorous physical activity (MVPA) minutes (-3 MVPA minutes/d, 95% CI = -5, 0) over the 3-year period as compared to non-fallers; however, physical activity did not significantly decline among non-injurious fallers. No longitudinal increases in FoF scores were observed in injurious or non-injurious fallers when compared to non-fallers.

CONCLUSION

Among visually impaired older adults, injurious falls identified prospectively over 12 months contributed to a significant decline in physical activity over a 3-year period, while minimal changes were observed in FoF.

Sociodemographic, behavioral, and medical risk factors associated with visual impairment among older adults: a community-based pilot survey in Southern District of Hong Kong

Background

The last visual survey of older adults in Hong Kong was a district-level study in 2002, with no assessment of behavioral and medical risk factors for visual impairment (VI). Our objectives were to determine the latest VI prevalence among older adults, significance of any spatial and temporal differences on the prevalence, and any associations of sociodemographic, behavioral and medical risk factors with VI from a multi-perspective analysis.

Methods

Community-based pilot survey of residents from a suburb of Hong Kong, aged ≥50, using a standardized questionnaire, was conducted in 2016.

Results

Of the 222 subjects, crude rates of bilateral and unilateral VI were 9.46 and 32.88%, respectively, or corresponding age-and-gender-adjusted rates of 6.89 and 30.5%. Older age and lower educational were associated with higher risk for unilateral VI, while older age, temporary housing, obesity and hyperlipidemia were associated with higher risk for bilateral VI. Smoking and alcohol-drinking status were not associated with unilateral or bilateral VI. Relative changes in ORs of hypertension or educational level on unilateral or bilateral VI were >  10% after adjusting for age. Interaction term between hyperlipidemia and gender or obesity was significant for unilateral VI. Gender, hypertension and cataract were not associated with unilateral or bilateral VI in general population of pooled analysis but were identified as risk factors in specific subgroups of stratified analysis. Refractive error (myopia or hyperopia) was significantly associated with VI in the eye-level analysis after adjusting the inter-eye correlation.

Conclusions

Sociodemographic and medical risk factors contributed to VI, but behavioral risk factors did not. Sociodemographic disparities of visual health existed. Age was the confounders of the VI-hypertension or VI-educational level relationships. Gender and obesity were more likely to have multiplicative effect on unilateral VI when combined with hyperlipidemia. Stratified analysis should be conducted to provide further insight into the risk factors for VI in specific populations. Uncorrected refractive error remains a significant cause of impaired vision. The spatial and temporal differences in bilateral VI prevalence from the previous local study indicates a territory-wide survey is needed to assess regional differences and overall prevalence of VI in Hong Kong.

Poorer Visual Acuity is Independently Associated With Impaired Balance and Step Length But Not Overall Physical Performance in Older Adults

This study examined the association between varying levels of visual acuity (VA) and physical performance (Short Physical Performance Battery) in older adults. A cross-sectional analysis of participants aged ≥50 years with a clinical diagnosis of vision loss across two studies was undertaken. Of 434 (96%) participants with available VA data, 74% (320/434) had nil, 7% (32/434) had mild, 8% (33/434) had moderate, and 11% (49/434) had severe visual impairment. Poorer VA of both better and worse eye was found to be significantly associated with poorer standing balance (p = .006 and p = .004, respectively); worse VA of the better eye was significantly associated with increased number of steps per meter (p = .005). Mean total Short Physical Performance Battery score of this study population was lower than published normative data for this age group. Physical activity programs for older people with reduced VA should be targeted at improving balance and gait skills to reduce falls risk.

The Consequences of Glaucoma on Mobility and Balance Control in the Older Adults: A Cross-Sectional Study

The aim of the study was to explore the functional impairments and related factors in older adults with moderate to advanced stages of glaucoma. Nineteen patients with glaucoma and 19 participants with no ocular disease performed step test and balance control tasks with analysis of overall stability index and fall risk index. Monocular and binocular Humphrey Visual Field tests were used to estimate visual field defect severity. The International Physical Activity Questionnaire was used to measure physical activity level. Patients with glaucoma showed poorer values for most of the mobility and balance control parameters with medium and large effect sizes (0.3-0.5). Mobility scores in patients were partly associated with their monocular visual field defect (rs = .507, p < .05). Low physical activity was identified as a risk factor for falls (rs = -.453, p < .05) and postural instability (rs = -.457, p < .05). Functional declines in dynamic tasks were not related to glaucoma severity. Older adults with glaucoma display impairment with mobility and balance control compared to controls, associated with the degree of monocular visual field loss and lower daily physical activity.

Keep your head down: Maintaining gait stability in challenging conditions

BACKGROUND

Peripheral vision often deteriorates with age, disrupting our ability to maintain normal locomotion. Laboratory based studies have shown that lower visual field loss, in particular, is associated with changes in gaze and gait behaviour whilst walking and this, in turn, increases the risk of falling in the elderly. Separately, gaze and gait behaviours change and fall risk increases when walking over complex surfaces. It seems probable, but has not yet been established, that these challenges to stability interact.

RESEARCH QUESTION

How does loss of the lower visual field affect gaze and gait behaviour whilst walking on a variety of complex surfaces outside of the laboratory? Specifically, is there a synergistic interaction between the effects on behaviour of blocking the lower visual field and increased surface complexity?

METHODS

We compared how full vision versus simulated lower visual field loss affected a diverse range of behavioural measures (head pitch angle, eye angle, muscle coactivation, gait speed and walking smoothness as measured by harmonic ratios) in young participants. Participants walked over a range of surfaces of different complexity, including pavements, grass, steps and pebbles.

RESULTS

In both full vision and blocked lower visual field conditions, surface complexity influenced gaze and gait behaviour. For example, more complex surfaces were shown to be associated with lowered head pitch angles, increased leg muscle coactivation, reduced gait speed and decreased walking smoothness. Relative to full vision, blocking the lower visual field caused a lowering of head pitch, especially for more complex surfaces. However, crucially, muscle coactivation, gait speed and walking smoothness did not show a significant change between full vision and blocked lower visual field conditions. Finally, head pitch angle, muscle coactivation, gait speed and walking smoothness were all correlated highly with each other.

SIGNIFICANCE

Our study showed that blocking the lower visual field did not significantly change muscle coactivation, gait speed or walking smoothness. This suggests that young people cope well when walking with a blocked lower visual field, making minimal behavioural changes. Surface complexity had a greater effect on gaze and gait behaviour than blocking the lower visual field. Finally, head pitch angle was the only measure that showed a significant synergistic interaction between surface complexity and blocking the lower visual field. Together our results indicate that, first, a range of changes occur across the body when people walk over more complex surfaces and, second, that a relatively simple behavioural change (to gaze) suffices to maintain normal gait when the lower visual field is blocked, even in more challenging environments. Future research should assess whether young people cope as effectively when several impairments are simulated, representative of the comorbidities found with age.

Structured Laser Light Improves Tripping Hazard Recognition for People with Visual Impairments

Purpose

Using a geometrically derived model and a virtual curb simulator, we quantify the degree to which a wearable device that projects a laser line onto tripping hazards in a pedestrian's path improves visual recognition for people with visual impairments (VI). We confirm this with subjects' performance on computer simulations of low contrast curbs.

Methods

We derive geometric expressions quantifying the visual cue users perceive when a single laser line is projected from their hip onto a curb. We show how the efficacy of this cue changes with the angle of the laser line relative to the subject's walking trajectory. We confirm this result with data from three subjects with VI in a simulated curb recognition task in which subjects classified computer images as an "Ascending," "Flat," or "Descending" curb.

Results

The derived model predicts that human recognition performance depends strongly on the laser line angle and the subject data confirms this (r ² = 0.86, P < 0.001). The laser line cue improved subject accuracy from a chance level of 33% to 95% for a simulated, one-inch, low-contrast curb at a distance of five feet.

Conclusions

Recognition of curbs in low light can be improved by augmenting the scene with a single laser line projected from a user's hip, if the angle of laser line is appropriately selected.

Translational Relevance

A majority of people with VI rely on their impaired residual vision for mobility, rather than a mobility aid, resulting in increased injury for this population. Enhancing residual vision could promote safety, increase independence, and reduce medical costs.

Epidemiological factors associated with health knowledge of three common eye diseases: A community-based pilot survey in Hong Kong

Objectives

To assess the proportions of respondents in the general community having heard or awareness, and their knowledge level, of three common eye diseases: age-related macular degeneration, cataract, and glaucoma. We also attempted to assess for risk factors that may be associated with any variations, which will help identify the areas of inadequate knowledge and demographics of potential audiences for focused health education.

Methods

We conducted a community-based pilot survey for the residents from a southern suburb of Hong Kong in early 2016, by inviting all aged 50 or above to complete a standardized questionnaire in the local community hall.

Results

Most of the 222 respondents have heard, or awareness, of cataract (92.79% or 81.98%, respectively), followed by glaucoma (86.94% or 52.70%, respectively), and age-related macular degeneration (51.35% or 29.28%, respectively). The results of Cronbach's alpha (α > 0.7) and Spearman's correlation coefficient (p < 0.01) suggested that the internal consistency, convergent and discriminant validities of the questionnaire were acceptable for the study population. Compared to a previous Hong Kong survey in 2002, the proportions of having heard of the three eye diseases were greater, but the overall knowledge remained limited. From a maximum knowledge score of 29, the median scores for age-related macular degeneration, cataract, and glaucoma were 9, 13, and 14, respectively. Except for the treatment of cataract, the knowledge level in most areas was low. Sociodemographic factors and medical history, rather than behavioral factors, were more likely to be associated with having a higher knowledge level. Subjects with family or friends with a history of glaucoma or age-related macular degeneration were more aware and knowledgeable, but not for subjects who were current and past smokers or alcohol drinkers. For age-related macular degeneration, gender modified the effect between age and knowledge level, while age was a confounder of having medical history, and having heard or awareness, of the disease.

Conclusion

Despite a larger proportion of the community having heard or awareness since 15 years ago, much effort remains for improving health knowledge of these three eye diseases in Hong Kong. We recommend targeting respondents with higher lifestyle risks, such as current and past smokers or alcohol drinkers, as a focused audience, and utilizing family members, relatives, or friends as another way of distributing health information.

Evaluation of Fear of Falling in Patients with Primary Open-Angle Glaucoma and the Importance of Inferior Visual Field Damage

Purpose

To evaluate fear of falling using the Fall Efficacy Scale-International (FES-I) in glaucoma patients and investigate its association with glaucomatous visual field loss.

Methods

This study included 273 patients (160 men and 113 women, average age 64.2 years) with primary open-angle glaucoma. Participants were requested to answer the FES-I questionnaire, translated into Japanese, in a face-to-face interview. The relationship between total FES-I score and the following variables was analyzed using multivariable linear regression: age, sex, better and worse best corrected visual acuity, total deviation (TD) in four visual field areas, body mass index (BMI), minutes walked per day, history of diabetes mellitus, history of systemic hypertension, number of previous falls.

Results

Univariate analysis suggested that total FES-I score increased with age and in woman, whereas other variables were not significantly associated with total FES-I score. However, age (coefficient, 0.23; standard error [SE], 0.04; P < 0.001), sex (coefficient, 1.79 for women; SE, 0.84; P = 0.034), mean TD in the inferior central area (coefficient, 0.92; SE, 0.22; P <0.001), and mean TD in the inferior peripheral area (coefficient, –0.86; SE, 0.21; P < 0.001) were included in the optimal model for total FES-I score.

Conclusions

Inferior peripheral visual field damage and preserved inferior central visual field sensitivity were associated with increased fear of falling assessed with FES-I in glaucoma.

Advanced glaucoma at diagnosis: current perspectives

Presentation with advanced glaucoma is a significant risk factor for lifetime blindness. The asymptomatic nature of glaucoma, particularly in early disease, means that substantial vision loss in one eye does not always translate into a perceptible loss of visual function. This, along with the lack of an effective screening strategy, contributes to late presentation. Those most at risk of presenting with advanced glaucoma have asymptomatic high intraocular pressure (IOP), no family history of glaucoma, are socially disadvantaged, and do not attend sight testing. Patients with glaucoma may have impaired functionality for daily activities, such as reading, walking and driving. Quality of life measures have shown this to be significantly worse in patients with more severe visual field loss, particularly if bilateral. In addition, quality of life decreases faster with further bilateral visual field loss when advanced visual field damage is present. Management of these patients requires disproportionally more resources than those with earlier disease. Both medical and surgical options are used as the initial approach to treat patients presenting with advanced glaucoma. The most recently published National Institute for Health and Care Excellence (NICE) guidelines suggest that patients presenting with advanced disease should be offered trabeculectomy as a primary intervention. However, more evidence is required to determine the best initial management. The Treatment of Advanced Glaucoma Study (TAGS) is being conducted, comparing primary medical management with primary mitomycin C-augmented trabeculectomy for people presenting with advanced open-angle glaucoma. The results of TAGS will provide robust evidence for the most appropriate initial intervention.

Dominance wave propagation during binocular rivalry in mild glaucoma

Glaucoma is both a progressive optic neuropathy and a neurodegenerative disease affecting structures in the primary visual pathway. Other vision-associated areas may also be affected, including the corpus callosum which is involved in inter-hemispheric transfer. This study evaluated dominance wave propagation during binocular rivalry to probe the efficacy of the inter-hemispheric transfer in 20 patients with mild open angle glaucoma and 25 age-matched controls. The two groups were matched for functional measures such as stereo-acuity, binocular visual acuity, and visual field mean deviation. Monocular functional and structural measures were equivalent for the left and right eye of each participant. Using Wilson et al.'s travelling wave paradigm [Nature, 412 (2001) 907-910], intra- and inter-hemispheric failure rates of traveling wave transmission and the travelling wave propagation times were recorded for the two groups. For the control group, the wave propagation failure rate was significantly greater for the inter- than for the intra-hemispheric condition, but for the glaucoma group, the failure rates were equally high for the two conditions. The wave propagation time was significantly longer for the inter- than for the intra-hemispheric condition for the control group, while the opposite was true for the glaucoma group. These results reveal changes in the wave dynamics of rivalry dominance in patients with mild glaucoma who otherwise have normal performance on standard functional measures.

Beyond intraocular pressure: Optimizing patient-reported outcomes in glaucoma

Glaucoma, an irreversible blinding condition affecting 3-4% adults aged above 40 years worldwide, is set to increase with a rapidly aging global population. Raised intraocular pressure (IOP) is a major risk factor for glaucoma where the treatment paradigm is focused on managing IOP using medications, laser, or surgery regimens. However, notwithstanding IOP and other clinical parameters, patient-reported outcomes, including daily functioning, emotional well-being, symptoms, mobility, and social life, remain the foremost concerns for people being treated for glaucoma. These outcomes are measured using objective patient-centered outcome measures (PCOMs) and subjective patient-reported outcome measures (PROMs). Studies using PCOMs have shown that people with glaucoma have several mobility, navigational and coordination challenges; reading and face recognition deficits; and are slower in adapting to multiple real-world situations when compared to healthy controls. Similarly, studies have consistently demonstrated, using PROMs, that glaucoma substantially and negatively impacts on peoples' self-reported visual functioning, mobility, independence, emotional well-being, self-image, and confidence in healthcare, compared to healthy individuals, particularly in those with late-stage disease undergoing a heavy treatment regimen. The patient-centred effectiveness of current glaucoma treatment paradigms is equivocal due to a lack of well-designed randomized controlled trials; short post-treatment follow-up periods; an inappropriate selection or availability of PROMs; and/or an insensitivity of currently available PROMs to monitor changes especially in patients with newly diagnosed early-stage glaucoma. We provide a comprehensive, albeit non-systematic, critique of the psychometric properties, limitations, and recent advances of currently available glaucoma-specific PCOMs and PROMs. Finally, we propose that item banking and computerized adaptive testing methods can address the multiple limitations of paper-pencil PROMs; customize their administration; and have the potential to improve healthcare outcomes for people with glaucoma.

Measuring Disability in Glaucoma

BACKGROUND

Glaucomatous visual field loss can have far-reaching and debilitating consequences on an individual, affecting one's ability to perform many important tasks. Although assessment of glaucoma-related disability constitutes an important part of clinical care, there remains a lack of organized, detailed information on the most suitable methods to capture disability in glaucoma.

PURPOSE

This review details the available methods to measure glaucoma-related disability and highlights important findings from studies utilizing these various methods.

METHODS

The literature was reviewed to identify papers evaluating disability in glaucoma and findings were summarized by research methodology used and area of impairment.

RESULTS

Identified methods for capturing glaucoma-related disability included qualitative descriptions, glaucoma-specific quality of life questionnaires, vision-specific questionnaires, general health questionnaires, functional domain-specific questionnaires, evaluation of task performance, event assessment (ie, falls and motor vehicle accidents), and real-world behavior (ie, daily physical activity). Findings using these methods show a strong relationship between glaucoma and/or glaucoma severity and difficulties with reading, driving, mobility, and other tasks such as prehension and facial recognition. In addition, glaucoma has financial and psychological implications on the patient, and can affect caregivers in some cases as well.

CONCLUSIONS

A wide variety of research tools have been used to characterize the disability resulting from glaucoma. Together, these tools show that glaucoma affects many abilities which are important for independent living. Strengths and limitations of the various research techniques are discussed so that future studies may use the method(s) most suitable for answering the research question posed.

Mobility-Related Gaze Training in Individuals With Glaucoma: A Proof-of-Concept Study

Purpose

Older adults with glaucoma show inappropriate gaze strategies during routine mobility tasks. Furthermore, glaucoma is a risk factor for falling and colliding with objects when walking. However, effective interventions to rectify these strategies and prevent these adverse events are scarce. We designed a gaze training program with the goal of providing proof-of-concept that we could modify mobility-related gaze behavior in this population.

Methods

A total of 13 individuals with moderate glaucoma participated in this study. We taught participants general and task-specific gaze strategies over two 1-hour sessions. To determine the efficacy of this gaze training program, participants performed walking tasks that required accurate foot placement onto targets and circumventing obstacles before and after training. We used a mobile eye tracker to quantify gaze and a motion-capture system to quantify body movement.

Results

After training, we found changes in the timing between gaze shifts away from targets relative to stepping on them (P < 0.05). In the obstacle negotiation task, we found a greater range of gaze shifts early in walking trials and changes in the timing between gaze shifts away from obstacles after training (P < 0.05), each suggesting better route planning. A posttraining reduction in foot-placement error and obstacle collisions accompanied these changes (P < 0.05).

Conclusions

Our results demonstrated that it is possible to modify mobility-related gaze behavior and mobility performance in older adults with glaucoma.

Translational Relevance

This study provides proof-of-concept for a gaze training program for glaucoma. A larger, randomized controlled trial is warranted.

Comparison of Visual Field Progression Rates Among the High Tension Glaucoma, Primary Angle Closure Glaucoma, and Normal Tension Glaucoma

Purpose

To compare the visual field (VF) progression among high tension glaucoma (HTG), primary angle closure glaucoma (PACG), and normal tension glaucoma (NTG) subjects in routine clinical care.

Methods

All patients had ≥5 VF tests using HFA, 24-2, SITA-standard strategy. We compared the progression between glaucoma subtypes after matching the VFs for baseline severity (mean deviation [MD]) and the age at presentation. Global VF progression was evaluated by linear regression analysis (LRA) of MD. For local VF progression, scotoma expansion (SE) defined as appearance of new scotoma and scotoma deepening (SD) defined by pointwise LRA were calculated. SE and SD were analyzed in three VF zones: superior arcuate (SA), inferior arcuate (IA), and central (C).

Results

A total of 310 HTG, 304 PACG, and 165 NTG eyes were included. When VFs were matched by baseline MD, a greater number (n = 20/76) of eyes with HTG showed significant progression compared to PACG (n = 9/76; P = 0.04). The number of progressing eyes were not significantly different between HTG and NTG (n = 11/76; P = 0.10) and between NTG and PACG (P = 0.65). When the baseline VFs were matched by age, the number of eyes showing significant progression were similar in all the subtypes. SA zone in HTG and NTG showed greater SE and SD compared to other zones (P < 0.05), whereas IA zone in PACG showed greater SE and SD compared to other zones (P < 0.05).

Conclusions

In our cohort of treated primary glaucoma with matched baseline severity, a greater proportion of HTG eyes progressed faster compared to PACG. SA zone in HTG and NTG and IA zone in PACG showed greater VF progression.

Can older adults' balance and mobility improve with visual attention training?

PURPOSE

We hypothesize that training older adults with a structured visual attention task will result in improved balance and mobility, potentially reducing their risk for falls.

METHODS

Healthy older adults aged 70 + took part in the study (mean age 80.3 ± 6 years). In this randomised control trial (NCT02030743), 15 participants were randomly assigned to a visual attention training group and 15 to a control group. Visual attention training was undertaken twice a week (45 min sessions) for 3 weeks (= six sessions) using versions of a selective attention useful field of view test and attended field of view test. The outcome measures were postural sway using a force plate, the Mini-Balance Evaluation Systems Test, the One-Legged Stance test, the 5 Meter Walking test, the Sit to Stand test, the Timed Up and Go test without and with a concurrent cognitive task.

RESULTS

There was a greater improvement in visual attention after training in the intervention group compared to the control group (p < 0.01). However, a mixed ANOVA (2× groups, 2× visit) showed no main effect of visit or group or any interaction for any of the force plate parameters. T tests of the changes over time between the intervention group and the control groups for the other balance and mobility assessment tools showed no improvement after the visual attention training.

CONCLUSION

It was found that there was no improvement in either mobility or balance after the visual attention training and no difference between the intervention and the control groups.

Predictors of Falls per Step and Falls per Year At and Away From Home in Glaucoma

OBJECTIVE

To determine where glaucoma patients most often fall and how integrated visual field (IVF) damage affects falls rates per year (falls/year) and per step (falls/step) at and away from home.

DESIGN

Prospective, observational cohort study.

METHODS

In 225 patients with glaucoma or suspected glaucoma, falls data were collected via calendars, fall location was classified through follow-up questionnaires, and steps taken at and away from home were judged by integrating data from annual week-long accelerometer and GPS trials. Main outcome measures were the association of IVF sensitivity with fall rates per year or step, stratified by location.

RESULTS

Participants took more away steps than home steps (2366 vs 1524, P < .001), and differences in away vs home steps did not vary with IVF sensitivity (P = .22). A total of 57% of falls occurred at home, with each home step twice as likely to result in a fall as compared to each away step (rate ratio = 2.02, P < .001). Worse IVF sensitivity was not associated with a higher rate of home falls/year or away falls/year (P > .1 for both), but was associated with a higher rate of home falls/step (rate ratio = 1.34/5 dB worse sensitivity, P = .03) and away falls/step (rate ratio = 1.47/5 dB worse sensitivity, P = .003).

CONCLUSIONS

In this glaucoma population, most falls occurred at home, and the risk of any step resulting in a fall was higher at home. Those with greater VF damage were more likely to fall for each step taken both at and away from home. Efforts such as home environmental modification should be considered in the visually impaired to prevent falls while maintaining physical activity.

What Is a Falls Risk Factor? Factors Associated with Falls per Time or per Step in Individuals with Glaucoma

OBJECTIVES

To determine whether visual field (VF) damage or other factors confer a similar risk of falling when falls are ascertained as a rate over time (falls/year) as when ascertained over activity (falls/step).

DESIGN

Prospective, observational cohort study.

SETTING

Clinic-based recruitment with real-world monitoring of falls and physical activity.

PARTICPANTS

Individuals with glaucoma or suspected glaucoma (N=230).

MEASUREMENTS

Participants recorded falls using daily calendars, with injuries identified in a follow-up questionnaire. Annual 1-week accelerometer trials were used to estimate steps. VF results from both eyes were merged to determine integrated VF sensitivity, with lower sensitivity indicating greater VF damage. Other potential risk factors for falls (age, sex, race, comorbid illness, polypharmacy) were determined using questionnaires.

RESULTS

The cumulative probability of falls was 45.2% at 12 months and 61.6% at 24 months; cumulative probability of injurious falls was 23.3% at 12 months and 40.0% at 24 months. Greater VF damage was associated with higher rates of falls/steps (incident rate ratio = 1.40/5 dB decrement in sensitivity; p = .004) but not with more falls/year (incident rate ratio = 1.25/5 dB decrement in sensitivity; p = .07). Several additional variables (older age, female sex, more comorbid disease) were also associated with a higher rate of falls/step (p < .02 for all) but not with falls/year (p > 0.10). Black participants had fewer falls/year than whites (p = .002) but did not differ in falls/step (p = .07). Similar results were obtained when injurious falls were analyzed.

CONCLUSIONS

Risk factors associated with frequent falls when walking (falls/step) are not properly identified when analyzing falls as a rate over time (falls/year). Given the clinical importance of preventing falls while preserving physical activity, falls assessment integrated with activity measurement is recommended when determining whether a risk factor is associated with falls. J Am Geriatr Soc 67:87-92, 2019.

Locations, Circumstances, and Outcomes of Falls in Patients With Glaucoma

PURPOSE

To characterize the locations, circumstances, and outcomes of falls in patients with varying degrees of glaucoma.

DESIGN

Prospective cohort study.

METHODS

Patients with suspected or diagnosed glaucoma completed monthly calendars reporting falls. After each fall, a 30-item questionnaire was administered to determine fall location, circumstances, and injury. Mean deviation on visual field (VF) testing was used to categorize glaucoma severity. Main outcome measures were fall locations, circumstances, and outcomes.

RESULTS

One-hundred forty-two patients experienced 330 falls. Falls were most likely to occur in/around the home (71%), and this likelihood did not vary significantly with severity of VF damage (P > .2). The most commonly cited fall circumstances were tripping (43.6%), slipping (31.3%), uneven flooring (23.5%), and poor vision (15.9%). The circumstances related to falls did not vary by severity of VF damage (P > .2), except for poor vision, which was more frequently cited in individuals with more advanced VF damage (P = .001). Forty-three percent of falls resulted in some injury; and the likelihood of injury did not vary by severity of VF loss (P = .60) or any other factor except floor type and number of comorbidities (P < .05 for all). Falls in persons with more severe glaucoma were more likely to result in a fracture (9.4%) or an emergency room visit (18.8%), though these associations did not persist in multivariable models (P > .5 for all).

CONCLUSIONS

Glaucoma patients fall mostly in/around the home and demonstrate similar fall circumstances across the spectrum of disease severity, suggesting that current fall prevention interventions, particularly those emphasizing home modification, may be an adequate starting point to prevent falls in this high-risk-group.

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

Purpose

Safe navigation requires avoiding objects. Visual field loss may affect how one visually samples the environment, and may thus contribute to bumping into objects and falls. We tested the hypothesis that gaze strategies and the number of collisions differ between people with glaucoma and normally sighted controls when navigating around obstacles, particularly under multitasking situations.

Methods

Twenty persons with moderate-severe glaucoma and 20 normally sighted controls walked around a series of irregularly spaced vertical obstacles under the following three conditions: walking with obstacles only, walking and counting backward to simulate a conversation, and walking while performing a concurrent visual search task to simulate locating a landmark. We quantified gaze patterns and the number of obstacle contacts.

Results

Compared with controls, people with glaucoma directed gaze closer to their current position (P < 0.05). They also directed a larger proportion of fixations (in terms of number and duration) to obstacles (P < 0.05). Despite this finding, considerably more people with glaucoma contacted an obstacle (P < 0.05). Multitasking led to changes in gaze behavior in both groups, and this was accompanied by a large increase in obstacle contacts among those with glaucoma (P < 0.05).

Conclusions

Glaucoma alters gaze patterns when negotiating a series of obstacles and increases the likelihood of collisions. Multitasking in this situation exacerbates these changes.

Translational Relevance

Understanding glaucoma-related changes in gaze behavior during walking in cluttered environments may provide critical insight for orientation and mobility specialists and guide the design of gaze training interventions to improve mobility.

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.