Ocular ischemic syndrome is the constellation of ocular signs and symptoms secondary to severe, chronic arterial hypoperfusion to the eye. Amaurosis fugax is a form of acute vision loss caused by reduced blood flow to the eye; it may be a warning sign of an impending stroke, as both stroke and retinal artery occlusion can be caused by thromboembolism due to atherosclerosis elsewhere in the body (such as coronary artery disease and especially carotid atherosclerosis). Consequently, those with transient blurring of vision are advised to urgently seek medical attention for a thorough evaluation of the carotid artery. Anterior segment ischemic syndrome is a similar ischemic condition of anterior segment usually seen in post-surgical cases. Retinal artery occlusion (such as central retinal artery occlusion or branch retinal artery occlusion) leads to rapid death of retinal cells, thereby resulting in severe loss of vision. Symptoms and signs
Those with ocular ischemic syndrome are typically between the ages of 50 and 80 (patients over 65); twice as many men as women are affected. More than 90% of those presenting with the condition have vision loss. Patients may report a dull, radiating ache over the eye and eyebrow. Those with ocular ischemic syndrome may also present with a history of other systemic diseases including arterial hypertension, diabetes mellitus, coronary artery disease, previous stroke, and hemodialysis.The condition presents with visual loss secondary to hypoperfusion of the eye structures. The patient presents with intractable pain or ocular angina.
The presence of HIV/AIDS or other causes of immuno-incompetence (see previous section), a history of having a low-grade lymphoma, and/or the presence of EVB+ plasmablasts in the diseases lesions would support the diagnosis of PBL. Differential diagnosis
Various lymphomas can exhibit the microscopic appearance, including plasmablastic cells, and presentation of PBL. These lymphomas can usually be differentiated from PBL by further examinations of the plasmablasts for various marker proteins and determining other factors that favor the diagnosis of these lymphomas rather than PBL, as indicated in the following descriptions. Anaplastic lymphoma kinase-positive large B-cell lymphoma
Unlike PBL, the plasmablastic cells in anaplastic lymphoma kinase-positive large B-cell lymphoma strongly express the product of the ACVRL1 gene, i.e. activin receptor-like kinase 1 (ALK1) and are not infected with EBV and therefore do not express this viruss EBER or BART RNAs. Human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified
Unlike PBL, the plasmablastic cells in human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified express products of herpesvirus 8 (also termed Karposi sarcoma virus) such as LANA-1 protein. Also unlike PBL, these plasmablastic cells do not express CD30, CD138, CD79a, or a clonal IgM antibody and usually are not EBV-infected and therefore usually do not express this viruss EBER or BART RNAs. Primary effusion lymphoma
In contrast to PBL, the plasmablastic cells in primary effusion lymphomas, whether HHV8-positive or HHV8-negative, usually strongly express CD45 and in HHV8 cases express HHV8 proteins such as the LANA-1 protein.