Upward-gaze palsy due to shunt malfunction.
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Cerebrospinal Fluid Shunts↗
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Results for “Computer vision”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Ocular manifestations of pituitary adenomas.
Fifty patients with pituitary adenomas were evaluated preoperatively by an ophthalmologist; of these, 68% had visual field defects, the most common (25%) a superior bitemporal depression and 16%, bitemporal hemianopsia. Almost 60% of patients with field defects had visual complaints; 38% had visual acuity in one eye of 20/60 or less. Patients with larger, nonsecreting tumors had more visual defects than patients with secreting pituitary adenomas.
Adenoma↗
Neurology of saccades and smooth pursuit.
During the period covered by this review a number of papers have been published on saccade and smooth pursuit research, conducted experimentally in monkeys and clinically in humans. In monkeys, using mainly electrophysiological methods, the roles of the frontal eye field, parietal eye field and supplementary eye field at the cortical level, and those of the paramedian pontine reticular formation, nucleus prepositus hypoglossi, interstitial nucleus of Cajal and superior colliculus at the brainstem level have been studied in great detail. In humans the same cortical areas have also been examined, mainly using functional imaging resulting in new information on the location of these areas and new hypotheses on the role of the superior parietal lobule in visual attention and that of the posterior part of the anterior cingulate cortex in motivation. Saccades, smooth pursuit and clinical applications of eye movement research are dealt with separately.
Animals↗
Progressive visual loss because of a suprasellar pneumatocele after trans-sphenoidal resection of a pituitary adenoma.
A 63-year-old man who underwent uneventful trans-sphenoidal resection of a pituitary adenoma with fat packing complained postoperatively of progressive binocular visual acuity loss. Neuroimaging showed a suprasellar pneumatocele compressing the optic chiasm and a communication between the sphenoid sinus and the sella. After a second trans-sphenoidal procedure to remove the air and fully pack the sphenoid sinus, visual acuity recovered dramatically. A rare complication of trans-sphenoidal surgery for pituitary adenoma, suprasellar pneumatocele probably forms through a ball-valve mechanism that results from incomplete packing of the sellar floor. This case highlights the need for effective sphenoid sinus packing and for ophthalmic monitoring after trans-sphenoidal surgery.
Adenoma↗
Vascular disease.
This last year has been a particularly busy one in the field of neuro-ophthalmology. The publication of the second, important, randomized multicentered trial in neuro-ophthalmology highlights the power of randomized trials to answer important clinical questions. This and other publications emphasize the pivotal role of vascular pathophysiology in production of neuro-ophthalmic disease. The progress in our understanding of mechanisms of vascular obstruction, risk factors for vascular disease and ocular manifestations, as well as technical advances in our approach to patients with vascular problems have continued the broad-front advancement in neuro-ophthalmology.
Cerebrovascular Disorders↗
Severe Graves' ophthalmopathy in pregnancy.
BACKGROUND: Thyroid ophthalmopathy is a rare extrathyroidal complication most commonly associated with Graves' disease. The disease course ranges from mild to severe, with severe cases resulting in major visual impairment and facial disfigurement. CASE: A 22-year-old primigravida developed severe thyroid ophthalmopathy during pregnancy, requiring high-dose steroids and surgical orbital wall decompression to restore visual acuity. CONCLUSION: Severe thyroid ophthalmopathy can occur in the euthyroid pregnant patient. Corticosteroid therapy and surgical intervention may be required during pregnancy in this clinical scenario.
Adult↗
Ophthalmic injuries in children involved in all-terrain vehicle crashes.
PURPOSE: To describe the spectrum of ophthalmic injuries in children involved in all-terrain vehicle (ATV) crashes. METHODS: We retrospectively reviewed the medical records of a level 1 children's trauma center to identify cases with ICD-9 codes pertaining to crashes involving ATVs and cross-referenced for ophthalmic trauma. From these cases, we documented the nature of the crash, patient's age, ophthalmic injuries received, and length of hospitalization. RESULTS: Twenty children, 5 to 16 years of age (mean, 11.1 years), involved in ATV crashes were admitted between June 1997 and April 2002. One was riding with an adult and 3 with other children; 16 were operating the vehicles alone at the time of their crashes. None was wearing a helmet, and all had head trauma. Nine patients had ophthalmic injuries, including lacerations of the eyelid (n = 5), orbital fractures (n = 9), and traumatic optic neuropathies (n = 2). The latter two had final visual acuities of count fingers and no light perception. The average length of hospitalization was 6.6 days. CONCLUSIONS: Ophthalmic trauma is a frequent complication of ATV crashes involving children. Injuries may range from minor lacerations to complex orbital fractures; visual loss may be severe. We believe that the age of the vehicles' operators and their failure to wear protective helmets contribute to the severity of injuries.
Accident Prevention↗
Brown tumor of secondary hyperparathyroidism involving the superior orbit and frontal calvarium.
A 29-year-old white man with chronic renal failure on hemodialysis presented with a subacute onset of painful proptosis, inferior displacement and limited upgaze of his right globe, and a tender, palpable fronto-temporal mass beneath the right scalp. A cranio-orbitotomy was performed to completely excise a large, necrotic, multilocular, cystic, heterogeneous mass. Histopathologic examination with light microscopy demonstrated the characteristic findings of a giant cell tumor. Based on the patient's history of renal failure and laboratory evidence of hyperparathyroidism, a diagnosis of brown tumor was determined.
Adult↗
A computational theory of human stereo vision.
An algorithm is proposed for solving the stereoscopic matching problem. The algorithm consists of five steps: (1) Each image is filtered at different orientations with bar masks of four sizes that increase with eccentricity; the equivalent filters are one or two octaves wide. (2) Zero-crossings in the filtered images, which roughly correspond to edges, are localized. Positions of the ends of lines and edges are also found. (3) For each mask orientation and size, matching takes place between pairs of zero-crossings or terminationss of the same sign in the two images, for a range of disparities up to about the width of the mask's central region. (4) Wide masks can control vergence movements, thus causing small masks to come into correspondence. (5) When a correspondence is achieved, it is stored in a dynamic buffer, called the 2 1/2-D sketch. It is shown that this proposal provides a theoretical framework for most existing psychophysical and neurophysiological data about stereopsis. Several critical experimental predictions are also made, for instance about the size of Panum's area under various conditions. The results of such experiments would tell us whether, for example, cooperativity is necessary for the matching process.
Humans↗
Abstracting human control strategy in projecting light source.
In this paper, we present a method of modeling human strategy in controlling a light source in a dynamic environment. We take a simple example of how to control the light source to avoid a shadow and maintain appropriate illumination conditions on the target area of attention to illustrate the procedure and method. This work is valuable to various applications of automatic light control from surgical room and space applications to inspections.
Humans↗
A systematic approach to standardizing the visual appearance of endometriotic lesions for artificial intelligence recognition.
INTRODUCTION: Numerous studies have shown that the diagnostic performance and reproducibility of visual recognition of endometriosis during laparoscopy are poor. The use of artificial intelligence (AI) seems relevant for exhaustive lesion recognition. Standardization of the visual classification of lesions, in the form of an ontology, is an essential prerequisite to enable medical experts to annotate surgical data consistently and subsequently allow engineers to train and build an artificial intelligence tool for endometriosis recognition. MATERIAL AND METHODS: A systematic search was conducted in the MEDLINE (via PubMed), EMBASE, and the Cochrane Library databases up to May 2022, aiming to identify studies describing the laparoscopic visual appearance of superficial endometriosis, endometriomas, and deep infiltrating endometriosis. The accumulated data in the literature concerning the visual appearance of the different forms of endometriosis were used to create an ontology that could be used for artificial intelligence applications. RESULTS: Out of 932 articles screened, 35 studies were selected based on the inclusion criteria of human subjects with histologically confirmed endometriosis lesions visualized via laparoscopy. The selected studies were reviewed to develop a visual ontology of endometriosis lesions observed via laparoscopy. The lesions were categorized into 4 classes and further subdivided into 11 subclasses: superficial (black, red, white, or subtle), adhesions (dense or filmy), deep (obliteration, retraction, or deformation), and ovarian (endometrioma or chocolate fluid). The positive predictive value (PPV) varied across lesion types: black lesions (PPV 47%-97%), red lesions (PPV 33%-100%), white lesions (PPV 20%-81%), and ovarian endometriosis (PPV 42%-98%). Nonspecific lesions such as adhesions (PPV 16%-50%) and subtle superficial lesions (PPV 0%-67%) presented lower PPVs. Deep endometriosis lesions, often buried within organs, required indirect signs (obliteration, retraction, deformation) for identification. CONCLUSIONS: The visual ontology proposed in this systematic search could facilitate the detection and classification of endometriosis lesions using artificial intelligence. This study highlights the challenges of reaching a consensus on lesion recognition and classification in AI projects due to the diverse visual presentations of endometriosis.
Humans↗
Cerebrospinal fluid findings in central neurocytoma.
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Adolescent↗
A 35-year-old female with growth and developmental retardation, progressive ataxia, dementia and visual loss.
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Adult↗
Acute orbital myositis: a case report.
A case of acute orbital myositis is presented in this report. CT scanning provided an immediate diagnosis and hence institution of treatment. There was a typically rapid response to steroids. A previous presentation, prior to the advent of CT, had been misdiagnosed as Tolosa-Hunt syndrome. Orbital pseudotumour can be acute or chronic, and acute orbital myositis is now regarded as one of five subtypes of the former.
Acute Disease↗
A visual field abnormality: ocular or cerebral cause?
The visual field can be affected by disorders involving any part of the visual pathway, from the retina to the striate cortex. The pattern of visual field damage can indicate the location of the disorder. The case is presented here of an 8-year-old girl with congenital glaucoma. Initial perimetry appeared consistent with glaucomatous field loss; however, this evolved into a homonymous quadrantanopia, indicating the presence of a cerebral lesion as the cause. Computed tomography and magnetic resonance imaging scans detected a large middle cranial fossa arachnoid cyst. Postoperatively there was resolution of the visual field defects secondary to the arachnoid cyst. The pattern of field loss was pivotal in this patient's management. Attention must be paid when caring for the patient with a chronic disease to ensure that concurrent conditions are diagnosed.
Arachnoid Cysts↗
Giant intracranial meningioma without hemianopic visual field loss.
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Female↗
Processing and analysis of form, colour and binocular disparity in the human brain: functional anatomy by positron emission tomography.
With the purpose of mapping those anatomical structures participating in the processing and analysis of form, colour and disparity information, we have measured, with positron emission tomography and [15O]butanol, regional cerebral blood flow (rCBF) as an indicator of regional cerebral metabolic activity in 13 right-handed male volunteers during visual discrimination of colour, form and disparity information. The brain images were anatomically standardized using a computerized brain atlas and statistically significant changes were localized by cluster analysis. The changes in rCBF between specific activation and reference states were measured and the volumes of changes were determined, as were the loci and volumes of areas commonly activated by two or three different tasks. Each of the tasks activated over a dozen distinct and separate fields in the cortex--in the occipital, parietal, temporal and frontal lobes as well as the cerebellum. A number of overlapping fields were commonly activated in two tasks (four in the form and colour tasks, five in the form and disparity tasks, and eleven in the colour and disparity tasks), and two field overlaps were present in all three tasks (in the right superior frontal and left lingual gyri). These findings indicate that, in a visual discrimination task, the processing and analysis of single visual submodalities take place in a number of cortical fields in the human brain. As the same visual submodality is processed and analysed by numerous fields and the same field may participate in the processing of different submodalities, a divergence-convergence pattern of information processing is present in the human brain. This observation supports a hypothesis based on earlier studies in primates, namely that information processing in the visual system requires the concerted activation of a relatively large number of fields of functional networks in the brain.
Adult↗
Functional neuroanatomy of the human near/far response to blur cues: eye-lens accommodation/vergence to point targets varying in depth.
The purpose of this study was to identify the networks involved in the regulation of visual accommodation/vergence by contrasting the cortical functions subservient to eye-lens accommodation with those evoked by foveal fixation. Neural activity was assessed in normal volunteers by changes in rCBF measured with PET. Thirteen right-handed subjects participated in three monocular tasks: (i) resting with eyes closed; (ii) sustained foveal fixation upon a LED at 1.2 m (0.83 D); and (iii) accommodating alternately on a near (24 cm, 4.16 D) vs. a far (3.0 m, 0.33 D) LED alternately illuminated in sequential 2 s epochs. The contrast between the conditions of near/far accommodation and of constant foveal fixation revealed activation in cerebellar hemispheres and vermis; middle and inferior temporal cortex (BA 20, 21, 37); striate cortex and associative visual areas (BA 17/18). Comparison of the condition of constant fixation with the condition of resting with closed eyes indicated activation of cerebellar hemispheres and vermis; visual cortices (BA 17/18); a right hemisphere dominant network encompassing prefrontal (BA 6, 9, 47), superior parietal (BA 7), and superior temporal (BA 40) cortices; and bilateral thalamus. The contrast between the conditions of near/far accommodation with closed-eye rest reflected an incremental summation of the activations found in the previous comparisons (i.e. activations associated with constant fixation). Neural circuits activated selectively during the near/far response to blur cues over those during constant visual fixation, occupy posterior structures that include occipital visual regions, cerebellar hemispheres and vermis, and temporal cortex.
Accommodation, Ocular↗