1/18. Management of traumatic optic neuropathy.Visual loss caused by trauma to the optic nerve is a well-recognized sequela to cranio-maxillofacial trauma. The authors reviewed their experience with 90 patients with pure traumatic optic neuropathy and optic nerve trauma with concomitant maxillofacial injuries. All patients were treated with intravenous steroids. Those not improving underwent extracranial optic canal decompression. patients with initial visual acuity of 20/100 or better all responded favorably with improvement in visual acuity or visual field to a course of intravenous megadose corticosteroids. patients with initial vision of 20/200 or worse who failed to respond to corticosteroids may have improved visual function after undergoing extracranial optic canal decompression. Preoperative and postoperative computed tomography scans on 6 patients enhanced with intrathecal iopamidol indicate the site of optic nerve compression to be at the optic canal. This article discusses the diagnosis and the medical and surgical treatment of pure and complex optic nerve injuries.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
2/18. Optic nerve decompression for indirect posterior optic nerve trauma.Posterior indirect optic nerve trauma is a rare but possibly dramatic event. Since spontaneous recovery is unlikely, medical treatment by megadose steroid therapy is advocated. Optic nerve decompression may be usefull, but is still controversial. Medial optic canal wall decompression seems best and may be achieved by various approaches.- - - - - - - - - - ranking = 0.33333333333333keywords = canal (Clic here for more details about this article) |
3/18. Optic nerve injury in children. A prospective study of 35 patients.Thirty-five children under 15 years of age with optic nerve injury are prospectively studies for their clinical presentation, radiological findings, visual evoked potentials and outcome. Over 50% were under 10 years of age. In half of the children, injury was due to fall from a height. Fracture of the skull was recorded in a third of the patients, and optic canal fracture was seen only in three children. Visual evoked potentials (VEP) were record in 30 children and were repeated several times in first three weeks. All the patients received corticosteroids and optic canal decompression was not carried out routinely. overall spontaneous visual recovery was observed in 12 patients. Among the 30 children in whom Veps were recorded, 17 children had repeatedly absent VEP, and none of the children showed wave formation, 10 (77%) had visual recovery. Only in 5 patients an optic canal decompression was carried out several weeks after injury. This study brings out the role of VEP in children with optic nerve injury.- - - - - - - - - - ranking = 1keywords = canal (Clic here for more details about this article) |
4/18. Delayed recovery from indirect optic nerve injury. A report of two unusual cases.Two patients with indirect optic nerve injury are reported. In one, head injury was minor, while in the second, the head injury was severe. Both the patients had immediate type of optic nerve injury with complete visual loss. CT scans for the orbit and optic canal were normal. Visual evoked potentials (VEP) repeatedly performed in the first 6-8 weeks were absent in both the patients. Onset of visual recovery was very late, in first case it was noticed after 12 weeks and in the second case visual recovery started after 8 weeks. Both the patients had partial visual recovery.- - - - - - - - - - ranking = 0.33333333333333keywords = canal (Clic here for more details about this article) |
5/18. Bilateral complete avulsion of ocular globes in a Le Fort III maxillofacial fracture: a case report and review of the literature.PURPOSE: The purpose of this paper is to demonstrate a case of bilateral complete avulsion of the globes following maxillofacial trauma. methods: A 23-year-old man with bilateral complete globe avulsion following a maxillofacial trauma. Both globes were luxated out of the orbit and suspended on the skin of the upper lid below the brows. No direct or indirect light reflexes or any eye movements could be noted. Computerized tomography showed complete lacerations of both optic nerves at a level just anterior to the optic canal. There were also multiple fractures corresponding to Le Fort III fracture with Le Fort II components. The brain parenchyma was normal with an exception of brain edema. As the globes were unsuitable for repositioning, both were enucleated. The maxillofacial fractures were immobilized with plates and screws. Although the patient gained consciousness with normal vital signs in the early postoperative period, he died on the ninth day due to pseudomonas aeruginosa infection, despite invasive antibiotic treatment. DISCUSSION: The optic nerve and the globes are very resistant to mild and moderate trauma. The avulsion of the nerve at the canalicular or more posterior level may demonstrate central nervous system complications resulting in life-threatening conditions. The most critical issue in complete globe avulsions with a transected optic nerve is to rescue the vision. In total transected optic nerves the final eyes could only have had cosmetic benefits. In spite of promising experimental research on optic nerve regeneration, there are unknowns, such as the methods to eliminate the risk of anterior segment ischemia and phthisis bulbi. CONCLUSIONS: Globe avulsions with a complete optic nerve cut remain a challenging problem. More research is required to better understand the pathophysiology of optic nerve repair.- - - - - - - - - - ranking = 0.66666666666667keywords = canal (Clic here for more details about this article) |
6/18. Optic nerve decompression via the lateral facial approach.Two cases of visual loss after lateral orbital wall fracture are presented: one with retrobulbar hematoma and evidence of optic nerve compression who failed to respond to lateral canthotomy and high-dose corticosteroid administration, and the second with immediate, total blindness associated with fracture of the bony optic canal. In both, extradural decompression of the orbit and optic nerve was achieved through the lateral facial approach with partial return of visual acuity and without surgical complications. The role of orbital and optic nerve decompression in the management of patients with blindness following orbital trauma is controversial. Orbital decompression may be of value for cases of post-traumatic visual loss unresponsive to medical management. If optic nerve injury is suspected as the cause, the additional step of decompression of the optic nerve is a logical but unproven procedure. The indications for optic nerve decompression are not established and should be considered only within the context of the specific needs of the individual patient.- - - - - - - - - - ranking = 0.33333333333333keywords = canal (Clic here for more details about this article) |
7/18. Predictive value of visual evoked potentials in unilateral optic nerve injury.Forty-five patients with posttraumatic unilateral blindness were prospectively analyzed. The computed tomography scan was normal in all and an optic canal fracture was recorded in only one patient. Visual evoked potentials were performed within 48 hours of initial evaluation and repeated within 7 to 10 days. Five patients had normal visual evoked potentials and 15 patients had abnormal responses. No visual evoked potentials were recorded in 25 patients. Five patients with normal visual evoked potentials had good visual recovery. Thirteen of the 15 patients with abnormal responses also showed significant visual improvement. This study showed that positive visual evoked potentials were reliable in predicting the visual outcome; 90% of the patients with positive visual evoked potentials had complete or partial visual recovery.- - - - - - - - - - ranking = 0.33333333333333keywords = canal (Clic here for more details about this article) |
8/18. Radiographical documentation of direct injury of the intracanalicular segment of the optic nerve in the orbital apex syndrome.In the radiographical evaluation of the orbital apex syndrome, standard radiographs, tomograms, and computed tomographic scans have proved useful in the demonstration of the bony pathology, especially for optic canal fractures. The limitation of these methods, however, remains in their inability to provide accurate delineation of the associated soft tissue pathology, including the presence of optic nerve sheath hematoma. Recent developments in computer technology and graphic imaging are now available to provide an accurate three-dimensional radiographical analysis of the extent of skeletal and soft tissue injury in the orbital apex syndrome. The physician, in essence, can perform a radiographical "living autopsy". The technique was used to evaluate a patient with bilateral apex syndrome. It clearly showed that a severe direct injury to the intracanalicular portion of the optic nerve was responsible for the development of blindness in this patient. The progression of optic nerve injury, from perineural sheath hematoma to the ultimate development of optic nerve atrophy and fibrosis, was radiographically documented.- - - - - - - - - - ranking = 2keywords = canal (Clic here for more details about this article) |
9/18. Severe visual disturbance after exposure of the optic canal during intranasal ethmosphenoidectomy.The cause of disturbed visual acuity associated with intranasal ethmosphenoidectomy is, on the one hand, a direct injury to the optic nerve. In this case, the disturbance in visual acuity develops immediately after the operation, and severe visual complications with a poor prognosis are found. On the other hand, in the two cases presented in this paper, the disturbed visual acuity develops postoperatively. In this case, it is necessary to take various possibilities into consideration, such as indirect effects of intraorbital bleeding, and damage to the lamina papyracea due to indirect and direct injury. Moreover, effects on the peri-optic nerve area and small blood vessels within the osseous optic canal should be considered. After thorough consideration and observation of the response to conservative therapy, such complications should be treated by investigating whether or not decompression of the optic nerve is effective.- - - - - - - - - - ranking = 1.6666666666667keywords = canal (Clic here for more details about this article) |
10/18. Clinical study of the pattern electroretinogram in patients with optic nerve damage.We have recorded both pattern and flash electroretinograms (ERG) in two patients with unilateral optic nerve damage due to optic canal fracture over one year. The pattern ERG from the affected eye was reduced in amplitude by approximately 40% in one patient, 60% in the other, compared with that from their other, normal eyes, while the flash ERG was normal in all eyes. Reduced pattern ERG responses may depend on retrograde degeneration following damage to the optic nerve. The pattern ERG, however, was not totally lost in the eyes with marked optic atrophy. There is a possibility that the pattern ERG contains both contrast and luminance components in various proportions.- - - - - - - - - - ranking = 0.33333333333333keywords = canal (Clic here for more details about this article) |
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