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Journal of Neuro-ophthalmology : the... Dec 2018Visual snow (VS) is a constant visual disturbance described as flickering dots occupying the entire visual field. Recently, it was characterized as the defining feature... (Review)
Review
BACKGROUND
Visual snow (VS) is a constant visual disturbance described as flickering dots occupying the entire visual field. Recently, it was characterized as the defining feature of a VS syndrome (VSS), which includes palinopsia, photophobia, photopsias, entoptic phenomena, nyctalopia, and tinnitus. Sixty percent of patients with VSS also experience migraine, with or without aura. This entity often is considered psychogenic in nature, to the detriment of the patient's best interests, but the high frequency of similar visual symptoms argues for an organic deficit. The purpose of this review is to clarify VSS as a true entity and elaborate the nature of individual symptoms and their relationship to each other.
EVIDENCE ACQUISITION
The literature was reviewed with specific regard to the clinical presentation and psychophysical, neurophysiological, and functional imaging studies in patients with defined visual disturbances that comprise VSS.
RESULTS
Consideration of the individual symptoms suggests that multiple factors are potentially involved in the development of VSS, including subcortical network malfunction and cortical hyperexcitation. Although there is substantial overlap between VSS and migraine syndromes in terms of co-occurring symptoms, both neurophysiological and neuroimaging studies provide substantial evidence of separate abnormalities of processing, supporting these as separate syndromes.
CONCLUSIONS
VSS is likely associated with either hyperactive visual cortices or, alternatively, impaired processing of simultaneous afferent information projecting to cortex. VSS likely results from widespread disturbance of sensory processing resulting in sensory misperception. There may be a number of syndromes associated with impaired sensory processing resulting in sensory misperception, including migraine, persistent perceptual postural dizziness, and tinnitus, which overlap with VSS. Elucidation of abnormality in one defined syndrome may provide a path forward for investigating all.
Topics: Humans; Migraine with Aura; Neuroimaging; Syndrome; Tinnitus; Vision Disorders; Visual Cortex; Visual Fields; Visual Perception
PubMed: 30095537
DOI: 10.1097/WNO.0000000000000702 -
Journal of Clinical Oncology : Official... Aug 1994
Topics: Breast Neoplasms; Female; Humans; Hypertension; Paclitaxel; Vision Disorders
PubMed: 7913722
DOI: 10.1200/JCO.1994.12.8.1741 -
Archives of Ophthalmology (Chicago,... Oct 1981Eleven patients had a syndrome characterized by (1) onset, in apparently healthy patients, usually women in the third to sixth decade of life, of floaters and photopsia,...
Eleven patients had a syndrome characterized by (1) onset, in apparently healthy patients, usually women in the third to sixth decade of life, of floaters and photopsia, blurred vision, and often followed later by night blindness and color blindness, (2) vitreous inflammation, (3) multifocal patches of depigmentation of the choroid and the pigment epithelium in the postequatorial fundi, (4) varying degrees of retinal edema and papilledema, narrowing of the retinal vessels, and mild optic atrophy, (5) moderate to severe electroretinographic findings, and (6) a variable rate of progression and severity, but with a tendency toward stabilization and preservation of good central vision in at least one eye. "Vitiliginous chorioretinitis" was chosen as the name for this syndrome because of the similarity of the appearance and evolution of the patches of choroidal depigmentation to that occurring in the skin of patients with vitiligo.
Topics: Adult; Chorioretinitis; Color Perception; Diagnosis, Differential; Electrooculography; Electroretinography; Female; Fluorescein Angiography; Fundus Oculi; Humans; Male; Middle Aged; Ophthalmoscopy; Visual Acuity; Visual Fields; Vitiligo
PubMed: 7295126
DOI: 10.1001/archopht.1981.03930020652006 -
Journal of Cataract and Refractive... Jul 2016A 22-year-old white man presented with photopsia of 3-year duration despite a corrected distance visual acuity of 20/20 in both eyes. Ophthalmic examination revealed...
UNLABELLED
A 22-year-old white man presented with photopsia of 3-year duration despite a corrected distance visual acuity of 20/20 in both eyes. Ophthalmic examination revealed multiple irregularly shaped white cortical opacifications of the lens in both eyes but no other significant ocular findings. One year after the photopsia onset, the patient experienced an episode of seizures with generalized tonic-clonic movements. Neurological follow-up examination demonstrated extensive brain calcification in the basal ganglia and frontal lobes, leading to a diagnosis of pseudohypoparathyroidism. Pseudohypoparathyroidism is a rare condition, and there are few reports of ocular findings with this underlying pathology. Our findings clearly demonstrate that even relatively unremarkable ocular signs can lead to diagnosis of severe systemic diseases. Therefore, the cataract surgeon should be aware of these conditions before removing the lens.
FINANCIAL DISCLOSURE
None of the authors has a financial or proprietary interest in any material or method mentioned.
Topics: Adult; Cataract; Cataract Extraction; Humans; Lens Implantation, Intraocular; Lens, Crystalline; Male; Pseudohypoparathyroidism; Visual Acuity; Young Adult
PubMed: 27492110
DOI: 10.1016/j.jcrs.2016.06.007 -
American Journal of Ophthalmology Mar 1995A 64-year-old man with a history of maxillary antrum melanoma had abrupt-onset night blindness and photopsia.
PURPOSE/METHODS
A 64-year-old man with a history of maxillary antrum melanoma had abrupt-onset night blindness and photopsia.
RESULTS/CONCLUSIONS
Ophthalmologic examination and electroretinogram suggested melanoma-associated retinopathy. Serum produced a weak but specific labeling of human bipolar cells by indirect immunofluorescence. Complete excision of melanoma may have contributed to low levels of circulating autoantibodies. The identity of the retinal bipolar antigen recognized by melanoma-associated retinopathy autoantibodies is needed for more accurate diagnosis.
Topics: Electroretinography; Humans; Male; Maxillary Sinus Neoplasms; Melanoma; Middle Aged; Retinal Diseases
PubMed: 7872401
DOI: 10.1016/s0002-9394(14)71185-7 -
Neurology Jul 1997In a prospective study of 32 consecutive patients with homonymous visual field defects due to ischemic infarcts we found hemianopic anosognosia (HAN), defined as the...
In a prospective study of 32 consecutive patients with homonymous visual field defects due to ischemic infarcts we found hemianopic anosognosia (HAN), defined as the unawareness of visual loss in the homonymous hemifield (or hemiquadrant), in 20 patients (62%). HAN, although occurring predominantly in right-side lesions in 16 of 26 patients (62%) was also present in four of six patients (or 67%) with left-side lesions. This group of patients has been presented in a prior report on positive spontaneous visual phenomena. HAN was associated with somatic anosognosia in nine patients and hemineglect in 17 patients. Dissociation between somatic and hemianopic anosognosia, as well as between hemineglect and HAN, was present in several patients, indicating that these phenomena may be independent of each other. Eight patients had pure homonymous hemianopia; that is, hemianopia without cognitive, motor, or somatosensory deficits. Four of these patients (Group A) had awareness of the visual deficit, whereas three patients (Group B) had HAN. Patients in these two groups had similar anatomic lesions. Patients with phosphenes, photopsias, or visual hallucinations were usually aware of their visual field loss. We suggest that HAN is most often related to failure of discovery of the deficits, occasionally to severe visual hemineglect, sometimes to generalized cognitive impairment, or to a combination of these factors. We further conclude (1) there is no specific cortical area for conscious visual perception; (2) visual awareness is processed by a distributed network including multiple visual cortices, parietal and frontal lobes, the pulvinar, and lateral geniculate bodies (lesions localized at various nodes or centers in the network may produce similar phenomena); and (3) both hemispheres are involved in visual processing and conscious awareness.
Topics: Aged; Aged, 80 and over; Brain; Brain Ischemia; Female; Hemianopsia; Hemiplegia; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Prospective Studies; Tomography, X-Ray Computed
PubMed: 9222175
DOI: 10.1212/wnl.49.1.88 -
Ophthalmic & Physiological Optics : the... Jan 2010To characterize photopsia in posterior vitreous detachment (PVD), retinal tears (RT) and rhegmatogenous retinal detachment (RRD).
AIMS
To characterize photopsia in posterior vitreous detachment (PVD), retinal tears (RT) and rhegmatogenous retinal detachment (RRD).
METHODS
Seventy seven patients presenting to an eye emergency department and vitreoretinal clinic with photopsia had documentation of their symptoms.
RESULTS
A total of 27 patients had PVD alone, 7 had RTs and 25 RRD. In patients with isolated PVD, photopsia were temporal (94%), lasting seconds (81%) and vertically orientated (59%) flashes. Patients with photopsia located in quadrants other than temporal were more likely to have RRD (p = 0.0003). Patients with an oblique or horizontal orientation of their photopsia were likely to have RRD or RT (p = 0.001, specificity 96%, sensitivity 40%).
CONCLUSIONS
Most patients with PVD have a typical presentation of photopsia, with temporal, vertically orientated, momentary flashes. Patients with RTs or RRD may describe subtle differences in their photopsia which may raise the index of suspicion for the presence of a complication from PVD.
Topics: Aged; Aged, 80 and over; Color; Female; Humans; Light; Male; Middle Aged; Prospective Studies; Retinal Detachment; Retinal Perforations; Vision Disorders; Vitreous Detachment
PubMed: 19709374
DOI: 10.1111/j.1475-1313.2009.00685.x -
British Journal of Hospital Medicine... Feb 2013Flashing lights (photopsia) and floaters are common visual phenomena and patients frequently present to hospital with these symptoms. This article provides a guide for... (Review)
Review
Flashing lights (photopsia) and floaters are common visual phenomena and patients frequently present to hospital with these symptoms. This article provides a guide for the non-specialist to the different pathologies that may result in photopsia and floaters.
Topics: Diagnosis, Differential; Eye Diseases; Eye Neoplasms; Humans; Lens Diseases; Migraine with Aura; Optic Nerve Diseases; Retinal Diseases; Vitreous Body; Vitreous Detachment
PubMed: 23411978
DOI: 10.12968/hmed.2013.74.2.91 -
Anales Del Sistema Sanitario de Navarra 2008Uveal metastases are the most frequent malign intraocular tumour, of which more than 80% are localized in the choroids. This, together with the progressive increase in... (Review)
Review
Uveal metastases are the most frequent malign intraocular tumour, of which more than 80% are localized in the choroids. This, together with the progressive increase in its incidence, makes its study and review necessary for a correct diagnosis and treatment in current clinical practice. Etiology varies according to the sex of the patient: lung carcinoma metastasises most frequently in men and breast carcinoma in women. These tend to multifocality and are generally localized in the posterior pole. Fifty percent of cases follow an asymptomatic development, but they can cause loss of vision, scotomas, metamorphopsias and photopsias. Charactersitic ophthamoscopic examination shows a placoid, homogenous choroidal lesion with a creamy appearance. The differential diagnosis must consider the amelanotic nevus, choroidal amelanotic melanoma, choroidal haemangioma, rear scleritis, choroidal osteoma, chorioretinitis, Harada's disease, rhegmatogenous retina detachment, uveal effusion syndrome, and serous central chorioretinopathy. An exhaustive history and complete ophthalmological examination are essential to the diagnosis, to which fluorescein angiography, ocular echography, fine needle puncture aspiration (FNPA), computerized tomography and magnetic resonance can be added as complementary tests. Treatment of these tumours is usually the systemic treatment of the primary tumour; the possibilities of local treatment are observation, external radiotherapy, transpupillary thermotherapy and enucleation.
Topics: Choroid Neoplasms; Humans
PubMed: 19169300
DOI: No ID Found -
Journal of Ophthalmic & Vision Research 2014Birdshot retinochoroidopathy (BSRC) is an uncommon, but well-characterized chronic, bilateral posterior uveitis, which is uniquely associated with the human leukocyte... (Review)
Review
Birdshot retinochoroidopathy (BSRC) is an uncommon, but well-characterized chronic, bilateral posterior uveitis, which is uniquely associated with the human leukocyte antigen-A29 phenotype. The disease presents predominantly in middle-aged Caucasian females who complain of blurred vision, floaters, photopsias, paracentral scotomas and nyctalopia. While autoimmune mechanisms are thought to play an important role in the pathogenesis of BSRC, its etiology remains unknown. Important questions remain in our understanding of BSRC with respect to its pathogenesis, epidemiology, optimal treatment, and prognosis, including the determinants of remission and relapse, as well as the best strategy for monitoring disease activity, progression and response to therapy with electroretinographic and psychophysical testing, established and emerging imaging modalities, and peripheral cytokines profiles.
PubMed: 25667738
DOI: 10.4103/2008-322X.143376