Rehabilitation and management of visual dysfunction following traumatic brain injury
Mark J. Ashley, David A. Hovda in Traumatic Brain Injury, 2017
In patients with visual loss as measured by decreased visual acuity or visual field, low vision devices, such as magnifiers (both optical and digital), special telescopes (some of which may be spectacle-mounted), or “field expanding” devices, can be applied. As our population has aged, more research and development has gone into rehabilitation for these types of visual loss, which are frequent sequelae of stroke and age-related eye disease. Therapy for homonymous hemianopia has been shown to increase speed and breadth of visual search and improve both objective and subjective measures of visual abilities on activities of daily living, including, in some cases, partial recovery of visual field loss.76,77 Therapy for visual spatial neglect can be similarly effective.78 Researchers at the Massachusetts Eye and Ear Infirmary have documented the effectiveness of using a multidisciplinary team, including ophthalmologists, optometrists, occupational therapists, and social workers, in increasing patients’ functional ability during visual rehabilitation.79
Stroke
Henry J. Woodford in Essential Geriatrics, 2022
Visual disturbances seen with TIAs include monocular vision loss, homonymous hemianopia and diplopia. Patients are often unable to distinguish between the loss of vision in one eye and the loss of one visual field (homonymous hemianopia). They may have tried covering each eye during the episode, which would provide more information, and so this should be asked about. Transient monocular blindness (also known as ‘amaurosis fugax') is a term for sudden visual loss in one eye. This may feel like a dark curtain coming across the visual field. There is no associated eye pain. Ophthalmoscopy should be performed to detect abnormalities such as cholesterol emboli (yellow blobs within the retinal arterioles), haemorrhages, optic nerve pallor and papilloedema. In this way, a primary ocular disorder mimicking TIA may be detected. Eye pain, redness and pupillary changes suggest an alternative diagnosis. ESR should be measured to exclude a vasculitic process.
Neurological Examination
Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner in The Integrated Nervous System, 2017
Pathway: The visual fields for each eye can be charted using a perimetry apparatus (explained in Chapter 9, including the foveal region, the blind spot and the periphery; Figure 2.1). The visual field is then divided in half; deficits in vision are described for each eye in terms of the temporal or nasal half of the visual field: a temporal (lateral) or nasal (medial) hemianopia. If the visual loss involves the visual field on the same side in both eyes, the clinical term is homonymous hemianopia; if not, the term is heteronymous hemianopia. (The details of the visual pathway are explained in Chapter 9, which will help to clarify the usage of this terminology.) A defect in the central region of the visual field that does not fit the boundary of a quadrant is called a scotoma.
Evaluation of Significance Maps and the Analysis of the Longitudinal Time Course of the Macular Ganglion Cell Complex Thicknesses in Acquired Occipital Homonymous Hemianopia Using Spectral-domain Optical Coherence Tomography
Published in Neuro-Ophthalmology, 2020
Tsutomu Yamashita, Atsushi Miki, Katsutoshi Goto, Syunsuke Araki, Go Takizawa, Yoshiaki Ieki, Junichi Kiryu, Akio Tabuchi, Yasuyuki Iguchi, Kazumi Kimura, Yoshiki Yagita
Eleven patients with stroke in the PCA territory and 40 normal control subjects were included in this study. Each participant underwent a comprehensive ophthalmological assessment, including the measurement of the best-corrected visual acuity, slit-lamp biomicroscopy, tonometry, dilated stereoscopic examination of the optic nerve head and fundus, colour optic disc photography and red-free RNFL photography. The visual fields were obtained by static automated perimetry with a Humphrey visual field analyser (Carl Zeiss-Meditec, Inc., Dublin, CA, USA). Patients with homonymous hemianopia underwent assessment with a Humphrey visual field analyser using the central 30–2 Fastpac software programme. Normal control subjects were evaluated with a Humphrey visual field analyser using the central 30–2 Swedish Interactive Threshold Algorithm (SITA) programme. The visual field tests were considered reliable based on fixation losses of <20% and false-positive and false-negative errors of <15%. The visual field defects evaluated on the initial visit included the mean deviation (MD), as determined by a Humphrey visual field analyser.
Neuro-Ophthalmic Literature Review
Published in Neuro-Ophthalmology, 2021
David A. Bellows, Noel C. Y. Chan, John J. Chen, Hui-Chen Cheng, Peter W. MacIntosh, Jenny A. Nij Bijvank, Michael S. Vaphiades, Konrad P. Weber, Sui H. Wong
Homonymous hemianopia (HH) affects 20–57% of stroke victims and currently there is no widely accepted treatment. Visual perceptual training had been shown to improve visual performance in some clinical studies. In this study, the authors conducted a multi-centre, randomised, controlled trial to investigate if motion discrimination training can improve perimetric mean deviation (PMD) on Humphrey Visual Field Analyser, motion discrimination performance- and visual-related quality of life (QOL). They enrolled 48 subjects with stroke-induced homonymous hemianopia and randomised these patients to receive training in either their sighted or deficit visual fields. The training consisted of repeated visual discriminations at a single location for 20–30 minutes per day at home for six months. Following training, subjects in the Deficit-field training group improved performance in terms of per cent correct at deficit field locations to a greater degree than Sighted-field trained subjects. Mean PMDs improved in Deficit-trained subjects (mean change OD 0.58 dB; mean change OS 0.84 dB) but not in Sighted-trained subjects (mean change OD 0.12 dB; mean change OS 0.10 dB). However, there were no significant differences between the two groups in either PMD or QOL. The authors concluded that although there was possible improvement in the deficit trained field for motion discrimination, they did not find a significant training effect on PMD differences compared to identical training within the visual intact field.
The impact of low vision on activities, participation, and goals among older adults: a scoping review
Published in Disability and Rehabilitation, 2022
Debbie Boey, Tamara Tse, Yi hui Lim, Mei Leng Chan, Kerry Fitzmaurice, Leeanne Carey
According to the definition by the World Health Organization (WHO), a person with low vision is one who has impairment of visual functioning even after treatment and/or standard refractive correction, and has a visual acuity of less than 6/18 to light perception, or a visual field less than ten degrees from the point of fixation, but who uses, or is potentially able to use, vision for the planning and/or execution of a task for which vision is essential [3]. It is different from blindness, where the person has no capability to use vision and is defined as presenting visual acuity of worse than 3/60 [4]. Age is the single best predictor for developing low vision and two-thirds of older adults with low vision are over age 65 years [5]. Age-related eye diseases including age-related macular degeneration (AMD), diabetic retinopathy and glaucoma are a primary cause of low vision [5] along with stroke and neurological diseases, such as Parkinson’s disease [6–8]. Nearly half of persons with stroke experience vision impairment including visual field losses and diplopia [8]. While neuro-ophthalmic conditions like homonymous hemianopia, which is a loss of half of the visual field on the same side in each eye [9], does not fulfill WHO’s low vision criteria, it still creates difficulties with ADL such as driving, shopping and financial management [10] and older adults with this condition are often referred for low vision rehabilitation. In addition, people with hemifield defects may have deficits associated with brain injury such as visual inattention, which has a different impact on ADL [11]. Therefore, hemifield defect is an important condition to consider in this paper which focuses on low vision and its impact on the daily activities and participation of older adults.
Related Knowledge Centers
- Optic Tract
- Scintillating Scotoma
- Visual Cortex
- Occipital Lobe
- Stroke
- Neoplasm
- Blood Vessel
- Hemianopsia
- Hemispatial Neglect
- Macular Sparing