1/581. carbon monoxide poisoning causes optic neuropathy.PURPOSE: To describe the electrophysiological and psychophysical effects of carbon monoxide (CO) poisoning on visual function. methods: Three patients are presented who suffered CO poisoning, two due to suicide attempts and one in the course of a road traffic accident. After a full ocular examination, Goldmann visual fields, flash and pattern visual evoked potentials (VEPs) and flash and pattern electroretinograms (ERGs) were tested. RESULTS: electrophysiology showed reduced or absent N95 components of the pattern ERG and delayed, reduced VEPs. A positive-negative-positive (PNP) VEP waveform was seen in two cases. In one case, where presentation occurred at an early stage, visual and electrophysiological function was improved with hydroxycobalamine. CONCLUSIONS: The combination of ERG and VEP findings suggest that CO poisoning can cause a toxic optic neuropathy that may have a similar aetiological mechanism to that in tobacco amblyopia. Early treatment with hydroxycobalamine may be of some benefit.- - - - - - - - - - ranking = 1keywords = optic (Clic here for more details about this article) |
2/581. Post-traumatic pituitary apoplexy--two case reports.A 60-year-old female and a 66-year-old male presented with post-traumatic pituitary apoplexy associated with clinically asymptomatic pituitary macroadenoma manifesting as severe visual disturbance that had not developed immediately after the head injury. skull radiography showed a unilateral linear occipital fracture. magnetic resonance imaging revealed pituitary tumor with dumbbell-shaped suprasellar extension and fresh intratumoral hemorrhage. Transsphenoidal surgery was performed in the first patient, and the visual disturbance subsided. decompressive craniectomy was performed in the second patient to treat brain contusion and part of the tumor was removed to decompress the optic nerves. The mechanism of post-traumatic pituitary apoplexy may occur as follows. The intrasellar part of the tumor is fixed by the bony structure forming the sella, and the suprasellar part is free to move, so a rotational force acting on the occipital region on one side will create a shearing strain between the intra- and suprasellar part of the tumor, resulting in pituitary apoplexy. Recovery of visual function, no matter how severely impaired, can be expected if an emergency operation is performed to decompress the optic nerves. Transsphenoidal surgery is the most advantageous procedure, as even partial removal of the tumor may be adequate to decompress the optic nerves in the acute stage. Staged transsphenoidal surgery is indicated to achieve total removal later.- - - - - - - - - - ranking = 0.6keywords = optic (Clic here for more details about this article) |
3/581. Visual loss with Langerhans cell histiocytosis: multifocal central nervous system involvement.A 42-year-old woman with a 6-year history of diabetes insipidus and progressive hypersomnolence presented with visual loss. neuroimaging showed infiltration in the hypothalamus, the optic nerve, and the chiasm, as well as multiple lesions in other areas of the brain parenchyma. biopsy showed Langerhans cell histiocytosis. This is an unusual presentation of Langerhans cell histiocytosis, involving the visual pathways without manifestations outside of the central nervous system. The differential diagnosis and the magnetic resonance imaging findings will be discussed.- - - - - - - - - - ranking = 0.2keywords = optic (Clic here for more details about this article) |
4/581. Compression of the visual pathway by anterior cerebral artery aneurysm.Visual failure is an uncommon presenting symptom of an intracranial aneurysm. It is even more uncommon in aneurysms arising from the anterior cerebral artery (ACA). We presented 2 patients with an aneurysm of the A1 segment of the anterior cerebral artery causing visual field defects. One patient presented with a complete homonymous hemianopia due to compression of the optic tract by a giant aneurysm of the proximal left A1 segment. The second patient had an almost complete unilateral anopia caused by compression of the optic nerve and chiasm by an aneurysm of the distal part of the A1 segment with a small chiasmatic hemorrhage and ventricular rupture.- - - - - - - - - - ranking = 0.4keywords = optic (Clic here for more details about this article) |
5/581. Treatment of paraneoplastic visual loss with intravenous immunoglobulin: report of 3 cases.BACKGROUND: Paraneoplastic visual loss is an autoimmune disorder believed to be caused by the remote effects of cancer on the retina (cancer-associated retinopathy [CAR]) or optic nerve. Both disorders may result in rapid and complete blindness. Spontaneous recovery of vision has not been reported. The serum of patients with CAR contains autoantibodies against recoverin, enolase, or unidentified retinal proteins. autopsy examination results of eyes of blind patients with CAR show complete absence of the retinal neurons involved in phototransduction. Corticosteroids and plasmapheresis are the only treatment options previously described. OBJECTIVE: To treat paraneoplastic visual loss. DESIGN AND methods: Three patients with metastatic cancer developed rapidly progressive loss of vision. The first patient had visual acuity of hand movements in each eye before intravenous immunoglobulin treatment. The second patient had visual acuity of light perception in both eyes. The third patient's visual acuity was 20/400 OD and 20/20 OS. Diagnostic tests included magnetic resonance imaging of the head and cytologic examination of the cerebrospinal fluid to exclude metastasis as the cause of visual loss and then an electroretinogram and serum tests for autoantibodies against retinal antigens to confirm the clinical diagnosis of CAR. patients 1 and 2 were treated with intravenous immunoglobulin (400 mg/kg per day) for 5 days; however, patient 3 received only a single dose due to adverse effects consisting of shortness of breath and itching. RESULTS: Within 24 hours of taking the first dose of intravenous immunoglobulin, the visual acuity of patient 1 improved from hand movements only in both eyes to 20/50 OD and 20/200 OS. After the third day of treatment, visual acuity in the left eye further improved to 20/40. Even with the improved acuity, Goldmann visual field perimetry results showed poor responses in both eyes. However, 2 weeks later there was marked visual field improvement, and visual acuity was maintained at 20/50 OD and 20/40 OS. Patient 2 had no improvements and continued to have light perception in both eyes. Patient 3 had improvements in visual field defects but remained 20/400 OD and 20/20 OS. CONCLUSION: Intravenous immunoglobulin may be another treatment option offered to patients with paraneoplastic visual loss in addition to corticosteroids or plasmapheresis because a review of the medical literature has shown no spontaneous improvements of visual function without treatment.- - - - - - - - - - ranking = 0.2keywords = optic (Clic here for more details about this article) |
6/581. A training sequence for low vision patients.A structured training program for teaching low vision patients to efficiently use their optical aids for reading tasks is presented. The arguments for the use of this particular training sequence is supported through the sample patient histories. The training sequences can be developed in any low vision practice and the materials are readily available. The importance of training in a low vision program is emphasized.- - - - - - - - - - ranking = 0.2keywords = optic (Clic here for more details about this article) |
7/581. Anterior ischaemic optic neuropathy in a patient with optic disc drusen.BACKGROUND: Although visual field defects are well-known complications of optic disc drusen, reduction in visual acuity with this condition is rare. METHOD/RESULTS: We report on a 68-year-old male with bilateral optic disc drusen who presented with monocular loss of vision in the right eye associated with an inferior altitudinal visual field defect and signs consistent with acute anterior ischaemic optic neuropathy, confirmed on fluorescein angiography. He also had a left inferior nasal step, but no evidence of glaucomatous cupping. The disc drusen were documented clinically and on B scan ultrasound and computed tomography. CONCLUSIONS: The diagnosis of acute anterior ischaemic optic neuropathy should be considered in patients with optic disc drusen who present with reduced visual acuity, particularly when the visual loss has been acute and non-progressive and is associated with altitudinal field loss and characteristic fluorescein angiography signs.- - - - - - - - - - ranking = 2.6keywords = optic (Clic here for more details about this article) |
8/581. Hypotensive ischemic optic neuropathy and peritoneal dialysis.PURPOSE: To report anterior ischemic optic neuropathy associated with systemic hypotension in a patient undergoing continuous ambulatory peritoneal dialysis. methods: Case report. A 58-year-old man undergoing continuous ambulatory peritoneal dialysis developed painless blurred vision in both eyes and bilateral optic disk swelling with an altitudinal field defect in the left eye. Twenty-four-hour ambulatory blood pressure monitoring was requested in addition to other routine investigations. RESULTS: Routine blood pressure measurement in the clinic was 130/86 mm Hg, but ambulatory blood pressure monitoring demonstrated pronounced early morning hypotension with individual readings as low as 91/41 mm Hg. CONCLUSIONS: renal dialysis can render patients hypotensive, and this may be associated with anterior ischemic optic neuropathy. The overnight drop in blood pressure may not be appreciated with routine blood pressure measurement. Therefore, 24-hour ambulatory blood pressure monitoring should be considered when investigating patients with suspected anterior ischemic optic neuropathy who are undergoing renal replacement.- - - - - - - - - - ranking = 1.6keywords = optic (Clic here for more details about this article) |
9/581. Topless optic disk syndrome without maternal diabetes mellitus.PURPOSE: To describe four cases of topless optic disk syndrome without maternal diabetes mellitus. METHOD: Four patients had incidentally discovered inferior visual field defects. RESULTS: Ophthalmoscopic examinations in all four patients disclosed superiorly displaced entrances of the central retinal artery and thinning of the superior peripapillary nerve fiber layers. One patient had a superior peripapillary crescent with pallor of the superior disk. These clinical findings were consistent with a diagnosis of superior segmental optic hypoplasia, the topless disk. None of the patients had mothers who had diabetes. CONCLUSIONS: The topless optic disk syndrome can occur in the absence of maternal diabetes mellitus.- - - - - - - - - - ranking = 1.4keywords = optic (Clic here for more details about this article) |
10/581. Fetal alcohol syndrome.BACKGROUND: Fetal alcohol syndrome (FAS) describes the systemic and ocular anomalies resulting from the teratogenic effect of maternal alcohol abuse during pregnancy. It is a leading cause of preventable birth defects in the U.S. case reports: Two case reports illustrate the characteristic findings in FAS. These include growth retardation, cognitive impairment, and facial dysmorphism. Ocular signs are prevalent, including small palpebral fissure, microcornea, strabismus, myopia, astigmatism, and optic nerve hypoplasia. DISCUSSION: Fetal alcohol exposure can lead to a wide spectrum of systemic defects and vision deficits. The increasing frequency of drinking among pregnant women in recent years should call more public attention to this detrimental yet preventable syndrome. CONCLUSION: The high frequency of ocular manifestations aids in making a diagnosis of FAS, which can be challenging. eye-care professionals can play an important role in patient management and the educational process.- - - - - - - - - - ranking = 0.2keywords = optic (Clic here for more details about this article) |
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