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Hemianopsia (and Scotoma)
Published in Alexander R. Toftness, Incredible Consequences of Brain Injury, 2023
Homonymous hemianopsia is the type that neurologists are usually referring to when they say “hemianopsia.” Homonymous hemianopsia is a visual defect where you can't see out of one half of each eye—the same half on each side. Pretend that for each of your eyeballs, there is a black line running from the top to the bottom right down the middle. Now, pretend that you have a marker with black ink and shade in everything on one side—left or right—of that line, turning your eyes into half-moons. Now, you are effectively blind to one side of your nose. This is similar to what homonymous hemianopsia is like.
Non-Organic Vision Loss
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ashwini Kini, Mangayarkarasi Thandampallayam Ajjeya, Padmaja Sudhakar
It is potentially easy to label a patient with NOVL and this can lead to devastating consequences if the patient actually has an organic underlying cause that was missed. Some of the intracranial mass lesions involving the pituitary or frontal lobe could have a normal structural exam and go undetected on CT scan and non-contrast MRI. A finger confrontation test could have a sensitivity as low as 20% in cases of bitemporal hemianopia and hence an inability to detect a field defect cannot be used to rule out an organic cause. Homonymous hemianopia could be missed in up to around 30% of the patients. Some of the patients with pituitary or frontal lesions could have accompanying psychiatric changes that could also add to the error in judgment.
Homonymous Hemianopia
Published in K. Gupta, P. Carmichael, A. Zumla, 100 Short Cases for the MRCP, 2020
K. Gupta, P. Carmichael, A. Zumla
Homonymous hemianopia indicates that the half loss of visual fields has affected similar fields in both eyes. For example, if the patient has right homonymous hemianopia, it means that he cannot see objects in the right half of the fields of both eyes.
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.
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.
Adaptation to post-stroke homonymous hemianopia – a prospective longitudinal cohort study to identify predictive factors of the adaptation process
Published in Disability and Rehabilitation, 2022
Claire Howard, Gabriela Czanner, Brinton Helliwell, Fiona J. Rowe
One type of post-stroke visual impairment is homonymous hemianopia, a loss of visual field to one side. Its existence has wide-reaching impact including loss of independence, increased risk of falls and difficulty reading [4]. People with hemianopic field defects cannot process the visual world in the same way as those with a full visual field [5]. They have difficulty in detecting and locating objects in the visual space to the affected side. People with hemianopic visual field defects report difficulty with navigating their environment; specifically, they report bumping into objects on their blind side [6].