View clinical trials related to Optic Nerve.
Filter by:Laparoscopic total hysterectomy is the most common gynaecological surgical procedure after caesarean section. In laparoscopic total hysterectomy, intraabdominal pressure increases, venous return decreases, hypercarbia and acidosis may occur due to pneumoperitoneum due to CO2 insufflation and upright trendelenburg position (TP). Cerebral blood flow, intracranial pressure (ICP) and intraocular pressure (IOP) increase. One study showed that TP and an intraabdominal pressure of mmHg significantly increased ICP. CO2 insufflation into the abdominal cavity causes upward displacement of the diaphragm, resulting in an increased risk of regurgitation, decreased lung volumes and compliance, atelectasis, increased airway resistance and ventilation-perfusion mismatch. At the same time, combined with the effects of general anaesthesia, a decrease in partial arterial oxygen pressure (PaO2) is expected in patients. The alveolar recirculation manoeuvre (ARM), is based on the technique of opening atelectatic lung fields by keeping the airway pressure high for a while. This manoeuvre can be performed with methods such as PEEP, CPAP, and pressure-controlled mechanical ventilation. High PEEP application may cause an increase in ICP and a decrease in cerebral perfusion pressure by increasing intrathoracic pressure and decreasing cerebral venous return. Therefore, intracranial pressure monitoring should be performed especially in patients with PEEP above 8-10 cmH2O. Intraventricular and intraparenchymal measurements, which are the gold standard methods for ICP monitoring, are invasive procedures with various risks. Noninvasive methods such as cranial CT, brain MRI, transcranial Doppler, and measurement of optic nerve sheath diameter (ONSD) can also be used for ICP measurement. Ultrasonography of the optic nerve sheath diameter is an increasingly common method because it is noninvasive and can be performed at the bedside. The optic nerve sheath is the continuation of the transverse subarachnoid space and the cerebral duramater. It is connected to the intracranial subarachnoid space with cerebrospinal fluid. Therefore, an increase in ICP increases the optic nerve sheath diameter (ONSD). Maissan et al. They think that ONSD reflects the changes in ICP simultaneously. The aim of this study was to evaluate the effect of ARM on intracranial pressure in patients undergoing total laparoscopic hysterectomy under general anaesthesia using optic nerve sheath diameter.
A retrospective study was conducted on 367 patients. CT PNS and head of the patients were evaluated for type of course of optic nerve according to DeLano's Classification.
This study is a prospective assessment of the accuracy of ocular ultrasound as a tool to measure the diameter of the optic nerve sheath and the eyeball transverse diameter in healthy adult patients presenting to the Emergency Department and have confirmatory imaging of the optic nerve as part of their clinical care.
We aim to determine the level of intraoperative PEEP that optimizes lung compliance without causing a rise in subdural pressure and if we can utilize optic nerve sheath diameter measurement as an indicator for ICP while optimizing lung compliance during supratentorial tumor surgeries.
The primary objective of the study was to evaluate the effect of Nerispirdine (50 mg or 400 mg) and placebo given orally as a single dose once a week in crossover design on latency of Visual Evoked Potentials (VEP) P100 in optic nerves. Secondary objectives included evaluation of the effect of Nerispirdine on VEP amplitude and other visual parameters including visual acuity and contrast, as well as evaluation of the safety and tolerability of Nerispirdine in patients with Multiple Sclerosis (MS). Contrast sensitivity and visual acuity examinations (in addition to Optical Coherence Tomography [OCT] and VEPs) were needed during the screening period for defining etiologic relationships (if non-MS related impairment) and for assessing the effect of treatment of age-related eye disease versus the MS-related vision impairment.
In the management of glaucoma, as for as in other optic nerve diseases, an important goal of ophthalmologists is represented by the possibility of influencing visual function. In this regard, Parisi et al [Ophthalmology 1999; 106:1126-1134.] suggested the intramuscular treatment with Cytidine-5-diphosphocholine (CDP-Choline or citicoline) to improve glaucomatous visual defects. In particular, recent studies reported the effects of citicoline on glaucomatous retinal and postretinal visual structures evaluated by electrophysiological examinations (PERG and VEP). It was observed that a 2-month period of treatment with citicoline may induce improvement in both ganglion cell function (PERGs with increase in amplitudes and shortening in times-to-peak) and in neural conduction along postretinal visual pathways (VEPs with increase in amplitudes and shortening in times-to-peak). The effects of citicoline on glaucomatous retinal and postretinal structures were not present 8 months after the end of treatment. However, performing several 2-month period of treatment with citicoline during a total period of 8 years, it was found a additional improvement of the glaucomatous retinal and postretinal impairment [Parisi V. Doc Ophthalmol. 2005 Jan;110:91-102). In this work, the investigators aimed to assess whether there similar visual function outcomes can be reached by the oral treatment with citicoline in patients affected by glaucomatous optic nerve disease as of as in other optic nerve diseases (i.e. non-arteritic ischemic optic neuropathy)