视神经撕脱伤早期诊断方法刍议

The humble opinion about early diagnosis of evulsion of optic nerve

目的观察视神经撕脱伤的影像学表现和视觉电生理特征,作为早期诊断的依据。方法视神经撕脱的早期因出血无法窥及眼底,建议以影像学及视觉电生理特征结合临床表现进行诊断,并举出临床所遇6例以资印证。结果视神经撕脱临床上主要特征有视力严重下降、相对性瞳孔传入障碍、视盘出血和玻璃体积血。本组2例完全性视神经撕脱及4例部分视神经撕脱均表现为:CT显示前段视神经增粗,可伴有巩膜后不均匀高密度影,出现视盘前丘状或扁平高密度影;B超可见视盘前或视盘边缘扁平或丘状隆起,伴有玻璃体积血者可有玻璃体腔内大量中强回声;视觉电生理表现为视网膜电图(ERG)的a或b波波幅降低并伴有视诱发电位(VEP)的潜伏期延迟及波幅降低;部分撕脱者可表现为ERG正常或伴有a或b波波幅降低,伴或不伴VEP潜伏期延迟和波幅降低。结论视神经撕脱伤早期无法视及眼底的病例可根据影像学和视觉电生理检查结果结合临床表现定诊断。

Objective To observe the imageology appearance and the vision electrophysiology of evulsion of optic nerve in case to get a definite diagnosis. Methods Diagnose depends on the feature of ERG, VEP, the imageology feature and the clinical manifestation, becouse of the vitreous hemorrhage. A retrospectively evaluated of 6 patients diagnosed as evulsion of optic nerve can authenticate it. Results The main clinical feature of evulsion of optic nerve are sudden and permanent visual loss, dilated fixed pupil, RAPD, bleeding of optic disc and vitreous hemo：Thage. The CT scan of the orbit revealed a thickened optic nerve on all 6 patients, there was haemorrhage within the orbit posterior to the globe on 4 patients, and the other 2 patients has a raised high density shadow before the optic disc. B-type Ultrasonography revealed a eminence view before or around the optic disc, a elevated area in the region of the optic disc can be seen. And it shows a devil of middle and high echo in the vitreous space becouse of vitreous hemorrhage. The ERG shows the amplitude of wave of a and b cut down and the VEP revealed poor response and showed a delayed incubation peri- od. Also the ERG can be normal on the partial evulsion of optic nerve. Conclusion Get a conclusive diagnosis of evulsion of optic nerve on the basis of the imageology appearance,the vision electrophysiology and the clinical manifestation for those who can＇t be seen the fundus.