Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344232 (blurred vision)
 2,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Visual disturbances are a common side-effect of many antiepileptic drugs. Non-specific retino- and neurotoxic visual abnormalities, that are often reported with over-dosage and prolonged AED use, include diplopia, blurred vision and nystagmus. Some anticonvulsants are associated with specific visual problems that may be related to the mechanistic properties of the drug, and occur even when the drugs are administered within the recommended daily dose. Vigabatrin, a GABA-transaminase inhibitor, has been associated with bilateral concentric visual field loss, electrophysiological changes, central visual function deficits including reduced contrast sensitivity and abnormal colour perception, and morphological alterations of the fundus and retina. Topiramate, a drug that enhances GABAergic transmission, has been associated with cases of acute closed angle glaucoma, while tiagabine, a GABA uptake inhibitor, has been investigated for a potential GABAergic effect on the visual field. Only mild neurotoxic effects have been identified for patients treated with gabapentin, a drug designed as a cyclic analogue of GABA but exhibiting an unknown mechanism while carbamazepine, an inhibitor of voltage-dependent sodium channels, has been linked with abnormal colour perception and reduced contrast sensitivity. The following review outlines the visual disturbances associated with some of the most commonly prescribed anticonvulsants. For each drug, the ocular site of potential damage and the likely mechanism responsible for the adverse visual effects is described.
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PMID:The effect of antiepileptic drugs on visual performance. 1512 41

This study evaluated pupillary postganglionic autonomic dysfunction and its relationship to visual disturbance in idiopathic Parkinson's disease (PD). Pupillary sensitivity was examined in relation to a parasympathomimetic agent [0.05% pilocarpine hydrochloride (PL)] and to a sympathomimetic agent [0.02% dipivefrine hydrochloride (DPE)] using infrared pupillography in 40 PD patients and 17 age-matched controls. Visual disturbances were evaluated as well, including blurring, photophobia, night blindness and involuntary eyelid closure in response to light. Pupillary supersensitivity to PL and DPE and their relation to visual disturbances were found to be significantly greater in PD patients than in controls (22.3 +/- 15.1 vs. 10.4 +/- 11.4%, P < 0.005, and14.5 +/- 14.5 vs. 4.9 +/- 8.7%, P < 0.01, respectively). In addition, pupillary sympathetic supersensitivity did not correlate with a reduction of 123I-metaiodobenzylguanidine (MIBG) cardiac accumulation. Patients with PD reported more blurred vision (P < 0.001) and involuntary eyelid closure in response to light (P < 0.05) than controls. Patients with supersensitivity to both PL and DPE complained more often of blurred vision than patients without supersensitivity (P < 0.05). Pupillary sensitivity to PL correlated significantly with a summed score for visual disturbance (P < 0.05, r = 0.417), but DPE sensitivity did not. PD patients have both parasympathetic and sympathetic postganglionic impairments affecting the pupil. Our findings demonstrate that parasympathetic dysfunction contributes significantly to visual disturbance in PD.
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PMID:Pupillary supersensitivity and visual disturbance in Parkinson's disease. 1826 41

Lymphocytic hypophysitis (LYH) is a rare neuroendocrine disorder characterized by autoimmune inflammation of the pituitary gland. Visual disturbance is one of the most common and serious symptoms of LYH. Most of the visual symptoms in LYH are secondary to compression of the optic chiasm and some reports have described direct inflammatory involvement of the optic pathways. We describe a 30-year-old man with a 9-day history of bilateral blurred vision. Ophthalmic examination demonstrated severely impaired vision without temporal hemianopsia. Hypothyroidism, hypocortisolism, and hypogonadism were detected in laboratory tests. Central diabetes insipidus was diagnosed by a hypertonic saline infusion test. MRI revealed thickening of the pituitary stalk and enlargement of the hypophysis, which was enhanced with gadolinium. High intensity of the posterior lobe was not recognized on T1-weighted images. These findings established a clinical diagnosis of lymphocytic panhypophysitis. Methylprednisolone pulse therapy was introduced and his visual acuity gradually recovered. The anterior pituitary function improved, but desmopressin was still required. Pattern-reversal visual evoked potentials (VEP) have been widely used to detect optic nerve lesions caused by multiple sclerosis and brain tumors. However, there have been no previous reports of their usefulness for LYH. The P100 latency in our case was slightly prolonged and the amplitude was markedly reduced. These findings are similar to ischemic optic neuropathy and other conditions in which axonal damage is prominent. The prolonged latency and low amplitude on VEP examination in this case showed rapid improvement in parallel with the recovery of visual acuity. Taken together, our case implies the usefulness of pattern-reversal VEP for the diagnosis of optic neuritis in LYH, especially for the evaluation of its pathogenic mechanisms.
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PMID:[A case of optic neuritis associated with lymphocytic hypophysitis revealed by pattern-reversal VEP]. 2138 96

Acute multifocal placoid pigment epitheliopathy (AMPPE) is thought to be caused by vasculitis of the choroid. Central nervous system involvement is rare. We report a case of a 28-year-old male who developed blurred vision (6/12 OD, 6/24 OS). Past medical history involved non-specific viral meningitis treated with intravenous antibiotics and antivirals. Subsequently, the patient complained of recurrent headaches. Based on typical clinical findings and fluorescein angiogram, he was diagnosed with AMPPE. Visual disturbance resolved without any systemic treatment. Six months later, visual symptoms recurred and resolved spontaneously, but his headache continued. A few months later, the patient developed acute progressive neurological signs and symptoms necessitating inpatient admission. Lacunar infarcts in the CNS were found, which had not been noted in previous neuro-imaging studies. Cerebral vasculitis associated with AMPPE was diagnosed and treated with systemic steroids and immune suppression. Currently, the patient remains asymptomatic under joined care of an ophthalmologist and a neurologist.
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PMID:Neurological symptoms associated with acute multifocal placoid pigment epitheliopathy: treatment dilemma and diagnostic issues. 2417 42

Epidemic nephropathy, i.e. nephropatia epidemica is a febrile illness caused by the Puumala virus and involving a transient impairment in kidney function. Additional commonly experienced symptoms include headache, backache and limb pain, as well as drowsiness or restlessness and nausea. Visual disturbances appear in approx. one third of those affected with the disease. Blurring of vision is the most common problem. We describe a patient case in which a previously healthy woman contracted epidemic nephropathy causing ocular symptoms that were strong.
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PMID:[Acute angle-closure glaucoma triggered by epidemic nephropathy]. 2623 20