The Study On Clinic And Pathophysiology Of Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) is the most popular kind of optic nerve injury, The visual acuity is damaged seriously. Its prognosis is adverse, and 50% left permanent visual acuity loss. The selection of treatment has been controversial of which the common treatment methods are drug therapy with corticosteroid and operation.Optic canal decompression by transnational endoscopic approach is the main operative way. Traumatic optic neuropathy of the injury mechanism, treatment modalities, surgical time, Principles of treatment and prognosis of factors, summarized the current progress of clinical diagnosis and treatment to improve the disease clinicians The level of awareness and treatment.Part One:The clinic analysis of traumatic optic neuropathyTo evaluate the therapeutic efficacy of operative and conservative treatment and analyze the clinical factors affecting the efficacy in traumatic optic neuropathy (TON).This paper reviews patients with TON from January 2005 to August 2010 in Tai Yuan central hospital. The 86 patients (86 eyes) with NOT are divided into two groups:EOND (40 eyes) and drug (46 eyes) and curative effects of the two groups are compared. The best operation time can be sought, based on the analysis of operations within or after 7 days since injures. This paper, regarding sex, age, eyes, visual acuity of no light perception (NLP), fracture, coma and injure reason as independent variable (X), and the curative effects as dependent variable(Y), carries on conditional logistic regression analysis and studies the factors on traumatic optic neuropathy. Results:1.Among the patients with no light perception, there is statistic difference(p=0.044)between the surgical group and the drug. The curative effect of operation is much better..2.Among the patients with light perception, the statistic difference between the two group(p=0.030).The effect of the surgery is better.3.According to the operation periods, there is difference(p=0.029) between injured patients operated within 7 days and after 7 days. It shows-the sooner, the better.Conclusion:1.Therapeutic effect of surgical treatment, on patients both with and without light perception, is better than that of medication therapy.2. Therapeutic effete of Patients in operation within 7days is better than that after 7days.3. NLP, coma are risk factors affecting traumatic optic neuropathy. Early surgical treatment after trauma could effectively protect visual acuity. Part two:The establishment and study of an experimental animal model of traumatic optic neuropathyTo establish animal model of TON that resemble to clinical state and study mechanical principle and change of physiology of its nerve injury for clinical diagnosis and treatment.10 mice heads were dissected to find the relationship of optic nerve and orbit, skull base. Big mice were regarded as the research objects.The method of Cui Zhi Li was repeated and improved.Mild and severe animal models of TON were established by Cui Zhi Li reformative operation separately. After the spring gun struck, all animals were observed on pupil and direct light reflex and received the examinations of pattern reversal visual evoked potentials (PR-VEP) and the observation of normal and injuryResults:1.After recovery from anesthesia, the mydriasis and disappearance or dullness of direct light reflex in all injury eyes. No brain contusion, no infection no orbital fracture, no death.1 optic nerve was broken with complete tunica vaginalis.2. The difference of latency and amplitude between the right and left eyes before struck showed no statistical significance (p>0.05).Conclusion:1. The reformative operation with high success rate can establish constant nerve injury. The animal model with little trauma and low mortality is resembled to clinical state,2.After injury, optic nerve goes through 3 stages:edema, hyperplasia and atrophy. The treatment can get better therapeutic efficacy in edema stage.3.In mild injury eyes, the injury deteriorated gradually.However, Part visual function remained. In severe injury eyes, pathomorphological changes were irreversible sooner after struck, and the visual function lost completely.4.There is a good correlation between PR-VEP and pathomorphology. PR-VEP can guide the clinical diagnosis and treatment.