Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined a patient with advanced keratoconus and a fixed and dilated pupil prior to keratoplasty. Local iris ischemia to the sphincter muscle appears to be the most likely etiology of this abnormality.
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PMID:Pupillary abnormalities in keratoconus. 391 50

The corneal findings in 60 patients with floppy eyelid syndrome seen at the Bascom Palmer Eye Institute over a 10-year period were determined by review of their medical records. Punctate epithelial keratopathy (45%), and both clinical (10%) and subclinical keratoconus were the most commonly encountered corneal disorders. Two patients developed progressive endotheliopathy (Chandler's syndrome and nonguttate endothelial dystrophy) during the period of observation. In contrast to previous reports in which almost all patients were obese men, 37% (n = 22) of our patients were women and only 29% of all patients were obese. All patients slept face down, usually on the most severely affected eye. Treatment by lid shortening surgery and/or an eye shield provided symptomatic relief. A pathogenetic theory is advanced that the degenerative changes in the tarsus result from the combination of local pressure-induced lid ischemia and systemic hypoventilation followed by reperfusion oxidation injury.
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PMID:Corneal disorders in floppy eyelid syndrome. 813 4

Morphologic examinations of biopsy specimens of the conjunctiva from 28 patients with keratoconus (56 biopsy specimens) revealed two types of pathologic processes: (1) acute and chronic immune inflammations of cell-mediated and mixed type (in 9 patients) and (2) fibrosis and acellular sclerosis as the result of the inflammation with the reduction of the microcirculatory bed and ischemia (19 patients). These data indicate the necessity of a differentiated approach to pre- and postoperative drug therapy of patients with keratoconus, exposed to perforating keratoplasty. The clinical picture does not permit a differentiation between types and phases of the inflammation for objective individualized prescription of drug therapy before and after perforating keratoplasty, therefore conjunctival biopsy is advisable in such cases as a diagnostic test. Histologic analysis gives data on the migration and proliferation of inflammatory cells, on the production of the intercellular substance, on the microcirculatory status. The results of this study helped the authors suggest a schematic approach to conservative therapy of patients suffering from keratoconus, aimed at inhibition of the inflammation.
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PMID:[Diagnostic biopsy of the conjunctiva in keratoconus]. 831 72

The aim of this study was assessment of the role of mast cells in inflammatory processes associated with keratoconus and corneal epithelial-endothelial dystrophy and clinical assessment of Lecrolin, a specially designed dosage form (eye drops) of potassium cromoglycate (intal) used as an antiallergic drug in asthma, rhinitis, etc. Examinations of 43 biopsy specimens of the conjunctiva from patients with keratoconus and epithelial-endothelial corneal dystrophy demonstrated the significance of immune inflammation in the pathogenesis of these diseases. Mast cells are a typical cell element participating in inflammation at all stages. The count of mast cells increases from 2.5 during the acute stage to 8.86 during the chronic stage, which is explained by absence of the leukocytic stage and proteolysis and stabilization of mature labrocyte degranulation associated with it. Reactions of mast cells with lymphocytes and monocytes/macrophages lead to proliferation of fibroblasts and chronic development of collagen formation. Close relationships between microvessels and mast cells promote stable spasms of the vessels, impairing the microcirculatory bed and leading to ischemia of the anterior segment of the eye. In such cases sodium cromolyne drugs (lecrolin) inhibiting histamine release and stabilizing mast cell membranes are recommended.
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PMID:[The role of the mast cells of the conjunctiva in the intercellular interactions in keratoconus and epithelial-endothelial corneal dystrophy]. 986 87

We studied 56 biopsy samples of conjunctiva and 50 corneal discs excised from 28 patients with acquired keratoconus cornea. The conjunctivas in all biopsy samples showed various stages of immune inflammation. Necrobiotic changes have been revealed in epithelium of the corneal discs going by the pathways of apoptosis--programmed cell death--and oncosis--initial edematic stage of necrobiosis. At the stage of acute inflammation they are due to cytotoxic effect of the lymphocytes, monocytes, and macrophages. Antibody-dependent cytotoxicity mediated by plasma and lymphoid cells predominates at this stage. At the reparative stage of inflammation ischemia, an inductor of apoptosis and oncosis, underlies necrobiotic changes in corneal epithelium.
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PMID:[The causes of necrobiosis and apoptosis of corneal epithelial cells during primary acquired keratoconus]. 1240 Mar 73

Urrets-Zavalia Syndrome (UZS) was described 50 years ago as the appearance of a fixed and dilated pupil following penetrating keratoplasty for keratoconus in patients receiving atropine. The mechanism of UZS has still not been fully determined, but an acute increase in intraocular pressure and ischemia of the iris most probably play a major role. Fixed and dilated pupils also occur in association with other ophthalmic surgeries, such as lamellar keratoplasties, cataract surgery, and glaucoma procedures. Some have questioned the existence of this syndrome, as well as the linkage to keratoconus and use of mydriatics. We review the pathophysiology, etiology, and clinical presentation of fixed and dilated pupils following ophthalmic procedures.
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PMID:Urrets-Zavalia syndrome (fixed and dilated pupil following penetrating keratoplasty for keratoconus) and its variants. 2456 Jan 26