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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The developments concern methods of application and therapeutic agents. Regarding drug aplication Ocusert has to be mentioned: inserted in the cul de sac of the eye once a week it releases a low concentration of a substance continuously and with a constant rate. For acetazolamid (Diamox) it has been shown, that in long term treatment much lower concentrations than usual are effective. Efforts regarding new local agents reducing intraocular pressure are stimulating as well as inhibiting the sympathetic tone. The practically most important discovery so far is Clonidine, whose pressure lowering mechanism is not quite clarified yet and which, due to other problems, demands a very critical indication. Beta-receptor-blocking agents, such as Propranolol could become somewhat important, as well as for some special indications the chemical sympathectomy by 6-Hydroxydopamine. The sympatholytic agent Guanethidine proves to be very valuable in special cases. Besides the pressure reducing treatment medicamentally achieved increase of the blood supply to the optic nerve becomes more important. It becomes more and more evident that the elevation of the stroke volume--thus heart output--by cardiac therapy is important what demands collaboration with colleagues of other disciplines.
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PMID:[Approaches in medical treatment in glaucoma (author's transl)]. 85 80

Using pneumotonometry combined with a Langham ocular blood-flow system, measurements of pulsatile ocular blood flow (POBF) were performed in eight ocular normotensive patients with implanted cardiac pacemakers, with the subjects assuming both the erect and the supine postures. Sequential measurements of POBF were made at pre-set values of heart rate over the physiological range between 60 and 120 beats/min at intervals of 10 beats/min. With patients in the supine position, measurements of cardiac output and stroke volume indices were also recorded by impedance cardiography. The mean pulse amplitude of the intraocular pressure (the ocular pulse) decreased as heart rate increased, and this change was statistically significant in both postures according to repeated-measures analysis of variance (erect: f = 18.7, P less than 0.0001; supine: f = 18.8, P less than 0.0001). As measured in supine patients following an increase in heart rate, the pulse amplitude decreased in parallel with a decline in stroke volume index (f = 18.8, P less than 0.0001). Up to a level of 90 beats/min, the mean POBF increased with heart rate, but it declined above this rate in both erect and supine postures. At all heart rates, intraocular pressure was higher when subjects were supine than when they stood erect (f = 4.3, P less than 0.001). At lower heart rates of 70 and 80 beats/min, ocular pulse volume and POBF were significantly lower in supine patients than in erect subjects (70 beats/min: t = 3.89, P less than 0.01 vs; t = 3.87, P less than 0.01; 80 beats/min: t = 2.85, P less than 0.05 vs; t = 2.87, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Factors influencing the ocular pulse--the heart rate. 176 98

Anterior ischaemic optic neuropathy is a stroke syndrome of the distal optic nerve, characterised by disc oedema and optic nerve dysfunction--loss of central vision, loss of colour vision, a relative afferent pupillary defect, and nerve fibre layer field loss. We prospectively evaluated the changes of intraocular pressure throughout the day in 16 patients with non-arteritic anterior ischaemic optic neuropathy and 15 normal control subjects of similar age and race. The peak intraocular pressure exceeded 21 mm Hg in five of the ischaemic optic neuropathy patients but none of the controls. The mean peak intraocular pressure was 19.9 mm Hg for the ischaemic optic neuropathy group versus 17.6 mm Hg for controls (p = 0.034). The range of intraocular pressure was also greater for the ischaemic optic neuropathy group (p = 0.030). Eight of 16 ischaemic optic neuropathy patients had a range of intraocular pressure of 6 mm Hg or more, compared with three of 15 control subjects. The intraocular pressure exceeded 21 mm Hg during a subsequent visit in two additional patients in whom the hourly determined intraocular pressure peaked at less than 21 mm Hg. Thus, seven of 16 of our ischaemic optic neuropathy group had an intraocular pressure exceeding 21 mm Hg during the study period. Raised intraocular pressure may be a predisposing factor in some patients who develop anterior ischaemic optic neuropathy.
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PMID:Anterior ischaemic optic neuropathy and intraocular pressure. 231 Jul 34

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial membrane and plays an important role in the maintenance of normal cardiac function. To evaluate the effects of ocular timolol on the cardiovascular system and determine the protective effect of CoQ10, 16 patients with glaucoma were studied using impedance cardiography. Following instillation of 1 mg timolol maleate in each eye, heart rate (HR) and stroke index (SI) decreased, and total peripheral resistance index (TPRI) increased significantly. Reexamination was performed after 6 weeks of 90 mg oral CoQ10. Despite decreases in HR, percent changes in HR were significantly less after CoQ10 at 120 min. Stroke index showed an initial increase which was not observed without CoQ10. These data suggest that CoQ10 delayed the appearance of inotropic blockade of timolol and hastened the disappearance of chronotropic blockade. Additional study of six normal volunteers with 6 weeks of oral CoQ10 showed a similar decrease of intraocular pressure after timolol instillation as compared to those without CoQ10. Thus, administration of oral CoQ10 in patients receiving ocular timolol may be useful in mitigating cardiovascular side effects without affecting intraocular pressure in the treatment of glaucoma.
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PMID:Effect of coenzyme Q10 on hemodynamic response to ocular timolol. 247 27

Ophthalmological data were obtained in 40 patients presenting with lacunar stroke. The stroke was verified clinically as well as by computed tomography. Vision was tested and the visual field, intraocular pressure, retinal arteriovenous passage time, arm-retina time, and erythrocyte flow velocity in the conjunctival capillaries were all determined; ophthalmoscopy was also carried out. Microcirculatory parameters were obtained from 21 patients. Significant disturbances of the retinal arteriovenous passage time were observed, but there were no significant disturbances of the conjunctival erythrocyte flow velocity. The concurrently measured haemorheological parameters were all pathological with the exception of the haematocrit. Ophthalmoscopic examination revealed arteriosclerotic alterations in 38 of 40 patients. These angiological and rheological findings confirm the importance of disturbed microcirculation in lacunar stroke.
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PMID:Circulatory parameters of the retina in patients with lacunar stroke. 395 Jun 63

Detection and evaluation of functionally significant carotid occlusive disease are effectively achieved by noninvasive pressure and/or volume measurements from the eye. Ocular arterial blood pressure is measured by applying either direct compression or suction to evaluate intraocular pressure to the point of arterial collapse. Carotid blood flow is evaluated as it affects ocular volume waveforms, which result from the difference between pulsatile arterial flow and relatively constant venous flow. The relationship between noninvasive measurements from the eyes and carotid blood flow can be predicted using simple models of the cervical-cerebral circulatory system. Proper models verify clinically observed correlations between pressure and volume measurements from the eye and the underlying carotid occlusive disease. Electrical analog circuits provide a method for varying model parameters to simulate abnormalities, producing waveforms with good similarity to waveforms recorded from patients with known vascular or ophthalmic pathology. Further model refinements can be contributed by interested investigators. By using the improved models the strengths and weaknesses of current tests and techniques can then be better defined. Techniques that have been widely used for screening and evaluating potential stroke patients can thereby be modified to give improved functional analysis of these patients.
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PMID:Pressure and volume measurements from the eye for detecting possible arterial obstruction. 639 3

A prospective masked study of the Langham Ocular Pressure Pulse Amplitude Procedure was made on 20 patients with arteriographically-confirmed completely patent carotid arteries (Group 1) and on 20 patients with either unilateral or bilateral stenoses of the internal carotid arteries (Group 2). The results are compared to similar studies previously reported on 20 patients with radiographically confirmed unilateral or bilateral occlusions of the internal carotid arteries (Group 3). The intraocular pressures, the pulse/intraocular pressure relations, and the ophthalmic arterial pressures were equal in pairs of eyes of Group 1 patients, and similar to those found in normal healthy subjects. The mean ophthalmic/brachial arterial pressure ratio in Group 1 patients was significantly higher than in normal subjects. In the Group 2 patients, the intraocular pressures were normal and all the measured parameters were similar in pairs of eyes, whereas, the ophthalmic/brachial arterial pressure ratios were significantly less than in the eyes of the Group 1 patients. The degree of stenoses of the internal carotid arteries (0 to 100%) as evaluated from arteriography varied inversely with the ophthalmic/brachial arterial pressure ratios (correlation coefficient 0.85). The coefficients of the sensitivity, the specificity, and the accuracy of the ophthalmic/brachial arterial pressure ratios in identifying the presence of stenotic lesions of the internal carotid artery defined by arteriography in the 120 eyes of the three groups were 89, 80, and 86% respectively. The ability of the Procedure to identify hemodynamic lesions of less than 50% is in keeping with published results of theoretical and experimental studies of the pressure gradient across stenoses in arteries with high rates of blood flow.
Stroke
PMID:Non-invasive diagnosis of mild to severe stenosis of the internal carotid artery. 646 53

We conducted a retrospective study of 29 diabetic patients (16 women and 13 men, all at least 60 years old) who underwent intraocular lens implantation (23 anterior chamber lenses, three iris-supported lenses, and three posterior chamber lenses) in conjunction with cataract extraction. The cataracts were either unilateral or, if bilateral, there was a four-line difference in visual acuity between fellow eyes. We included only patients with no diabetic retinopathy or only minimal background angiopathy. There were no surgical complications in any of the eyes. Transient postoperative increases in intraocular pressure were easily controlled with medication. Final corrected visual acuities ranged from 20/20 to 20/200; 20 of the 29 patients achieved final visual acuities of 20/40 or better. In two patients, background retinopathy became active, leading to significant macular edema four months and one year later. In both cases, the macular edema decreased visual acuity from 20/30 to 20/200, although the visual acuity in one eye returned to 20/40 after laser photocoagulation. One patient had a cerebral vascular accident resulting in cortical blindness five months postoperatively and another developed rubeosis iridis and neovascular glaucoma 15 months postoperatively.
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PMID:Experience with intraocular lens implants in patients with diabetes. 686 84

Glycerol is a potent osmotic dehydrating agent with additional effects on brain metabolism. In doses of 0.25-2.0 g/kg glycerol decreases intracranial pressure in numerous disease states, including Reye's syndrome, stroke, encephalitis, meningitis, pseudotumor cerebri, central nervous system tumor, and space occupying lesions. It is also effective in lowering intraocular pressure in glaucoma and shrinking the brain during neurosurgical procedures. Hyperosmolality with rebound cerebral overhydration is of concern, especially in patients with altered blood brain barriers. They may be avoided if glycerol is administered on an intermittent rather than a continuous basis. Intravascular hemolysis does not occur with oral use. When administered intravenously, hemolysis can be minimized by using glycerol 10% in dextrose 5% with normal saline at rates of 6 mg/kg/min or less. However, intravenous doses of 1-2 g/kg every 2 hr can be administered safely in severe cases of elevated ICP. In such patients, glycerol serum concentration, serum osmolality and ICP monitoring are required to optimize glycerol therapy.
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PMID:Glycerol: a review of its pharmacology, pharmacokinetics, adverse reactions, and clinical use. 692 4

3 case studies of migrainous patients taking oral contraceptives (OCs) are presented in this report. The role of OCs in triggering a migraine attack and possibly elevating the risk of a stroke in a patient with migraines is examined. In the 1st case, a 27-year old white female accountant complained of temporal throbbing headaches associated with nausea, vomiting, hazy vision, small scotomas, and photophobia. The patient had been having the headaches twice a month since 1978 and she took Fiorinal to relieve them. Her physician diagnosed the headaches as migraine. The patient acknowledged that she started getting these headaches after beginning to use OCs 3 years earlier. Her family history revealed that her mother had severe migraine headaches which sometimes were accompanied by unilaterial paresthesia, as well as high blood pressure. Ophthalmoscopy, slitlamp, accommodation, and intraocular pressure findings were unremarkable. The patient was counseled about the factors which can trigger a migraine attack and was advised that eliminating these factors may reduce the frequency and intensity of the headaches. The patient was advised that OCs could increase her risk of having a stroke, especially with her family history. Her family physician subsequently reduced the dosage of her OCs. 5 months later the patient reported that she was trying to avoid the migraine triggering factors (e.g., she was wearing her sunglasses). Her headaches had become less frequent and less severe. The 2nd patient also began to have migraine attacks after beginning to use OCs. The 3rd patient's headaches became so severe after taking the pill that she consulted a neurologist. The 2nd and 3rd patients complained that the headaches were most severe at the time each month when they resumed OC use. None of the 3 patients discontinued OC use. The 2nd and 3rd patients were using a low estrogen OC, and the 1st patient was put on a low estrogen dosage after this optometrist's recommendation to her physician. Encouraging the patients to discuss the dosage of OCs with their family physician may be one of the ways to reduce the unwanted effect of the pill. The effect of OCs goes beyond triggering a headache. They may trigger a stroke particularly if the patient has a family history of high blood pressure as did the patients in this study. Differential diagnosis of migraine headaches includes muscle contraction, tension, sinus, and allergic headaches. Optometrists can be most helpful to the patients by counseling them to avoid the triggering factors. Glare, a triggering factor, could be reduced by tinted spectacles.
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PMID:Migraine and oral contraceptives. 714 75


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