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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We characterized the perceptual, functional, and structural abnormalities associated with retinal ischemia during a cotton wool spot episode and its sequelae. The border of the visually salient field anomaly mirrored the quantitatively measured relative scotoma. Results of resolution perimetry and high resolution imaging indicated that there was a substantial loss of retinal ganglion cells within the affected region. A disruption in retinal nerve fiber arrangement was found at the cotton wool spot and within the arcuate relative scotoma. The presence of the arcuate relative scotoma is consistent with the hypothesis of failed signal transmission along the axons that pass through the cotton wool spot. The different levels of loss associated with the arcuate and focal scotomas indicate different underlying pathologies.
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PMID:The mechanisms of vision loss associated with a cotton wool spot. 1970 85

A 32-year-old man with blurred vision in the right eye and headache presented with anterior uveitis, an intraocular pressure (IOP) of 60 mmHg, an open angle, no visual field defects, and normal optic nerve. He had a history of five previous similar attacks. In each of the previous instances, his anterior uveitis and high IOP were controlled with antiglaucoma medications and topical steroids. However, at the fifth attack, his optic disc was pale and a superior paracentral visual field defect was shown. Brain magnetic resonance image studies were normal. This case represents that a recurrent Posner-Schlossman syndrome (PSS)-induced optic disc atrophy likely due to ocular ischemia caused by a recurrent, high IOP. Although PSS is a self-limiting syndrome, we should manage high IOP and prevent ischemia of the optic nerve head by treating with ocular antihypertensive medications.
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PMID:Optic disc atrophy in patient with Posner-Schlossman syndrome. 2320 6

Paracentral occlusive retinopathy is an uncommon manifestation of sickle cell disease. If macular ischemia is not reversed, permanent vision loss can result. The authors report the successful use of exchange transfusion to treat unilateral paracentral occlusive retinopathy secondary to sickle cell disease in a 23-year-old man with hemoglobin SS disease. Initial presentation demonstrated arteriolar occlusion, perivenous hemorrhages, vessel tortuosity, and areas of retinal ischemia. Visual acuity was count fingers, and the patient noted a paracentral scotoma. Following transfusion, there was restoration of arteriolar flow as documented with fluorescein angiogram, and visual acuity returned to 20/20.
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PMID:Reversal of paracentral occlusive retinopathy in a case of sickle cell disease using exchange transfusion. 2404 19

Terson syndrome is defined as the incidence of intraocular hemorrhage in patients following a subarachnoid or intracranial bleed. A 38-year-old female with both intraretinal and subretinal hemorrhages secondary to Terson syndrome underwent repair of a ruptured cerebral aneurysm. One month following resolution of the macular hemorrhages, a paracentral scotoma persisted. Multimodal imaging (morphological and functional) confirmed the presence of acute macular neuroretinopathy Type 2 associated with deep retinal capillary ischemia. Optical coherence tomography angiography illustrated the selective involvement of the deep retinal capillary plexus. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:764-767.].
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PMID:Terson Syndrome Associated With Acute Macular Neuropathy Type 2. 2890 39

The retinal capillary vasculature serves the formidable role of supplying the metabolically active inner and middle retina. In the parafoveal region, the retinal capillary plexuses (RCP) are organized in a system of three capillary layers of varying retinal depths: the superficial capillary plexus (SCP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). While the dynamic flow through these plexuses is complex and not completely understood, current research points to a hybrid model that includes both parallel and in series components in which blood flows in a predominantly serial direction between the superficial vascular complex (SVC) and deep vascular complex (DVC). Each capillary plexus autoregulates independently, so that under most conditions the retinal vasculature supplies adequate blood flow and oxygen saturation at varying depths despite diverse environmental stressors. When the flow in the deep vascular complex (i.e. ICP and DCP) fails, an ischemic lesion referred to as Paracentral Acute Middle Maculopathy (PAMM) can be identified. PAMM is an optical coherence tomography (OCT) finding defined by the presence of a hyperreflective band at the level of the inner nuclear layer (INL) that indicates INL infarction caused by globally impaired perfusion through the retinal capillary system leading to hypoperfusion of the DVC or specifically the DCP. Patients present with an acute onset paracentral scotoma and typically experience a permanent visual defect. Lesions can be caused by a diverse set of local retinal vascular diseases and systemic disorders. PAMM is a manifestation of the retinal ischemic cascade in which the mildest forms of ischemia develop at the venular end of the DCP, i.e. perivenular PAMM, while more severe forms progress horizontally to diffusely involve the INL, and the most severe forms progress vertically to infarct the inner retina. Management is targeted toward the identification and treatment of related vasculopathic and systemic risk factors.
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PMID:Paracentral acute middle maculopathy and the organization of the retinal capillary plexuses. 3278 59

Purpose: Coronavirus Disease 2019 (COVID-19) can cause conjunctivitis in up to 31.6% of patients. Additionally, retinal findings compatible with retinal microvascular ischemia have also been associated with coronavirus disease in asymptomatic patients. We describe a case of bilateral retinal changes compatible with microangiopathy occurring during the late phase of COVID-19. Case report: A 50-year-old man with bilateral pneumonia and positive polymerase chain reaction for SARS-CoV-2 developed an arcuate visual field defect in his left eye. Funduscopy revealed multiple, bilateral cotton-wool spots without haemorraghes. OCT-angiography revealed multifocal areas of retinal microvascular ischemia in the superficial plexus, the largest of which corresponded to the arcuate scotoma observed in the automated perimetry. Conclusion: Visual field defects due to retinal microangiopathy can occur during the late phase of COVID-19. Vascular changes observed in the retina may mimic what may be happening in other, less-accessible organs.
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PMID:Symptomatic Retinal Microangiophaty in a Patient with Coronavirus Disease 2019 (COVID-19): Single Case Report. 3328 32


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