Screening for Patients with Mild Alzheimer Disease Using Frequency Doubling Technology Perimetry

Contrast Sensitivity, Visual Field, Color Vision, Motion Perception, and Cognitive Impairment: A Systematic Review

OBJECTIVES

To examine relationships between visual function (ie, contrast sensitivity, visual field, color vision, and motion perception) and cognitive impairment, including any definition of "cognitive impairment," mild cognitive impairment, or dementia.

DESIGN

Systematic review and meta-analyses.

SETTING AND PARTICIPANTS

Any settings; participants with (cases) or without (controls) cognitive impairment.

METHODS

We searched 4 databases (to January 2024) and included published studies that compared visual function between cases and controls. Standardized mean differences (SMD) with 95% CIs were calculated where data were available. Data were sufficient for meta-analyses when cases were people with dementia. The Joanna Briggs Institute checklists were used for quality assessment.

RESULTS

Fifty-one studies/69 reports were included. Cross-sectional evidence shows that people with dementia had worse contrast sensitivity function and color vision than controls: measured by contrast sensitivity (log units) on letter charts, SMD -1.22 (95% CI -1.98, -0.47), or at varied spatial frequencies, -0.92 (-1.28, -0.57); and by pseudoisochromatic plates, -1.04 (-1.59, -0.49); color arrangement, -1.30 (-2.31, -0.29); or matching tests, -0.51 (-0.78, -0.24). They also performed more poorly on tests of motion perception, -1.20 (-1.73, -0.67), and visual field: mean deviation, -0.87 (-1.29, -0.46), and pattern standard deviation, -0.69 (-1.24, -0.15). Results were similar when cases were limited to participants with clinically diagnosed Alzheimer disease. Sources of bias included lack of clarity on study populations or settings and definitions of cognitive impairment. The 2 included longitudinal studies with follow-ups of approximately 10 years were of good quality but reported inconsistent results.

CONCLUSIONS AND IMPLICATIONS

In the lack of longitudinal data, cross-sectional studies indicate that individuals with cognitive impairment have poorer visual function than those with normal cognition. Additional longitudinal data are needed to understand whether poor visual function precedes cognitive impairment and the most relevant aspects of visual function, dementia pathologies, and domains of cognition.

Influence of Diabetes Mellitus on Glaucoma-Relevant Examination Results in Primary Open-Angle Glaucoma

Primary open-angle glaucoma (POAG) is no longer considered an isolated eye pressure-dependent optic neuropathy, but a neurodegenerative disease in which oxidative stress and neuroinflammation are prominent. These processes may be exacerbated by additional systemic diseases. The most common are arterial hypertension, dyslipidemia, and diabetes mellitus. Using diabetes mellitus as an example, it will be shown how far-reaching the influence of such a systemic disease can be on both the functional and the structural diagnostic methods for POAG. This knowledge is essential, since these interferences can lead to misinterpretations of POAG, which can also affect therapeutic decisions.

A Retrospective Cohort Study on the Difficulties of Diagnosing and Managing Glaucoma in Patients with Coexistent Neurodegenerative Disease

Aim

To investigate the limitations of diagnosing glaucoma in patients with coexistent neurodegenerative disease (NDD) by collecting information on demographics, examination findings, optical coherence tomography (OCT), and visual field (VF) tests.

Materials and methods

Retrospective cohort study of patients with primary open-angle glaucoma and coexistent dementia, multiple sclerosis (MS), Parkinson's disease (PD), or cerebrovascular accident (CVA) from 2014 to 2020. We included patients with a minimum of 3 years of follow-up. Demographics, ophthalmic exam, OCT, and VF findings were reported and compared across NDD groups using the Chi-squared and analysis of variance tests.

Results

We included 199 patients with glaucoma and coexistent NDD, including dementia (51.3%), CVA (11.2%), PD (18.1%), and MS (19.6%). Cupping, neuroretinal rim thinning, pallor, and peripapillary atrophy of the optic nerve were most frequently observed. There was a high number of missing values from OCT to VF tests, and zero patients had a complete OCT or VF test. Additionally, 67.8 and 77.4% of patients received <1 OCT and VF/year, respectively. Retinal nerve fiber layer (RNFL) thinning was observed most frequently in the superior (33.2% OD and 30.7% OS) and inferior (25.6% OD and 30.2% OS) quadrants, with the most significant thinning seen in CVA patients compared to other NDDs (p < 0.05). Glaucoma hemifield tests (GHTs) were abnormal in 23.1% OD and 22.6% OS, and the average mean deviation was -7.43 [standard deviation (SD) 8.23] OD and -8.79 (SD 7.99) OS.

Conclusion

The OCT and VF tests are frequently unavailable and may be confounded in patients with coexistent glaucoma and NDDs, complicating glaucoma diagnosis and management.

Clinical significance

Diagnosing and managing glaucoma in patients with coexistent NDD is difficult, given the lack of available and reliable OCT and VF testing data. Providers may be forced to rely on intraocular pressure (IOP) and other imperfect measures.

How to cite this article

Ciociola EC, Patel K, Blahnik T, et al. A Retrospective Cohort Study on the Difficulties of Diagnosing and Managing Glaucoma in Patients with Coexistent Neurodegenerative Disease. J Curr Glaucoma Pract 2023;17(3):126-133.

Visual disorders and driving ability in persons with dementia: A mini review

Background

Impaired driving ability in patients with Alzheimer’s disease (AD) is associated with a decline in cognitive processes and a deterioration of their basic sensory visual functions. Although a variety of ocular abnormalities have been described in patients with AD, little is known about the impact of those visual disorders on their driving performance.

Aim

Aim of this mini-review is to provide an update on the driving ability of patients with dementia and summarize the primary visual disorders affecting their driving behavior.

Methods

Databases were screened for studies investigating dementia, associated visual abnormalities and driving ability.

Results

There is consistent evidence that dementia affects driving ability. Patients with dementia present with a variety of visual disorders, such as visual acuity reduction, visual field defects, impaired contrast sensitivity, decline in color vision and age-related pathological changes, that may have a negative impact on their driving ability. However, there is a paucity in studies describing the impact of oculovisual decline on the driving ability of AD subjects. A bidirectional association between cognitive and visual impairment (VI) has been described.

Conclusion

Given the bidirectional association between VI and dementia, vision screening and cognitive assessment of the older driver should aim to identify at-risk individuals and employ timely strategies for treatment of both cognitive and ocular problems. Future studies should characterize the basic visual sensory status of AD patients participating in driving studies, and investigate the impact of vision abnormalities on their driving performance.

Parallel processing in human visual cortex revealed through the influence of their neural responses on the visual evoked potential

The neural response in the human visual system is composed of magno-, parvo- and koniocellular input from the retina. Signal differences from functional imaging between health and individuals with a cognitive weakness are attributed to a dysfunction of a specific retinal input. Yet, anatomical interconnections within the human visual system obscure individual contribution to the neural response in V1. Deflections in the visual evoked potential (VEP) arise from an interaction between electric dipoles, their strength determined by the size of the neural population active during temporal - and spatial luminance contrast processing. To investigate interaction between these neural responses, we recorded the VEP over visual cortex of 14 healthy adults viewing four series of windmill patterns. Within a series, the relative area white in a pattern varied systematically. Between series, the number of sectors across which this area was distributed doubled. These patterns were viewed as pattern alternating and on-/off stimuli. P100/P1 amplitude increased linearly with the relative area white in the pattern, while N135/N1 and P240/P2 amplitude increased with the number of sectors of which the area white was distributed. The decreases P100 amplitude with increasing number of sectors is attributed to an interaction between electric dipoles located in granular and supragranular layers of V1. Differences between the VEP components obtained during a pattern reversing display and following pattern onset are accounted for by the transient and sustained nature of neural responses processing temporal - and spatial luminance contrast and ability of these responses to manifest in the VEP.

Impact of Alzheimer's Disease in Ocular Motility and Visual Perception: A Narrative Review

PURPOSE

Alzheimer's disease (AD) is a neurodegenerative disease generating a progressive neuronal loss as well as cognitive deficiencies. This disease can be accompanied by ocular manifestations, including alterations in ocular motility and visual perception. The aim of the current review article was to collect all the information about these alterations and to analyze if there is scientific evidence supporting the potential use of these changes as biomarkers of the disease.

METHODS

A bibliographic search was performed using two different databases, Pubmed and Google Scholar, as well as a search of material in non-peer reviewed journals about Alzheimer's and Neurology. A total of 227 articles were found in the initial search, but only 76 were included considering their relevance according to the purpose of the reviewResults: This narrative review describes the findings obtained in this area to this date, confirming that deficiencies in saccades is the most common condition among AD patients. Furthermore, other visual alterations have also been reported in these patients, including a compromise of visual acuity and contrast sensitivity, fluctuations of colour vision, stereopsis impairment and visual field losses. Likewise, other complex visuo-spatial and visuo-perceptual impairments can be present. More studies are still needed to understand better what type of changes occurs in ocular alignment, binocularity, and fixation pattern in AD patients.

CONCLUSIONS

AD is associated to visual perception and ocular motility alterations. All the scientific information found in this review should be considered as a guide for designing future studies and to define adequate clinical protocols for the visual evaluation of patients with AD, considering the cognitive limitations that are normally present in this type of patients.

Vision in Alzheimer's disease: a focus on the anterior afferent pathway

Visual dysfunction has long been recognized as a manifestation of Alzheimer's disease (AD), particularly in the form of visuospatial impairment during all stages of disease. However, investigations have revealed findings within the anterior (i.e., pregeniculate) afferent visual pathways that rely on retinal imaging and electrophysiologic methodologies for detection. Here we focus on the anterior afferent visual pathways in AD and the measures used for assessment, including optical coherence tomography, electrophysiology, color vision testing and threshold visual field perimetry. A brief summary of higher order visual dysfunction is also included to allow the reader to keep in context the broader findings of afferent visual dysfunction in AD.

Retinal Nerve Fiber Layer Thickness Measurement by Spectral-Domain Optical Coherence Tomography in Patients with Major Depressive Disorder

INTRODUCTION

In recent years, an increasing number of studies have researched retinal nerve fiber layer (RNFL) changes in neurodegenerative disorders. In this study, our aim was to determine structural RNFL changes in patients with major depressive disorder.

METHODS

A total of 30 patients with major depressive disorder and 30 age- and sex-matched controls were recruited. Using optical coherence tomography (OCT), the peripapillary RNFL thickness in major depressive disorder patients and control subjects was measured and compared at each location.

RESULTS

Patients with major depressive disorder did not show a statistically significant reduction in overall peripapillary RNFL thickness.

CONCLUSION

Our study showed that RNFL thickness is not reduced in major depressive disorder patients and that OCT is not a useful tool for diagnosing and monitoring the progression of major depressive disorder. This study suggests that the pathophysiology of unipolar depression is different than in neurodegenerative disorders, pervasive developmental disorders, schizophrenia, and bipolar disorder.