Jalali Subhadra, Padhi Tapas Ranjan, Bansal Reema, Sahoo Kalyani, Basu Soumavaya, Mathai Annie
Srimati Kanuri Santhamma Centre for Vitreo-Retinal Diseases, L V Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, India.
Doc Ophthalmol. 2013 Oct;127(2):155-63. doi: 10.1007/s10633-013-9390-1. Epub 2013 May 18.
To report two cases of visual loss following snake bite.
Retrospective review of medical records including history, examination finding, fundus details and investigation reports (visual field, electroretinogram, visual evoked potential and optical coherence tomogram) at two centers.
Two cases of snake bite presented to us with reduction of vision at 1 and 3 months after the incident. The subnormal b wave and abnormal pattern electroretinography in one case pointed at inner retinal dysfunction and neurotoxicity as the cause of visual loss in an apparently normal-looking fundus. The electronegative b wave in the other gave us a clue that the optic atrophy was consecutive (secondary to inner retinal dysfunction due to central retinal artery occlusion).
When presented late, diagnosis of visual loss secondary to snake bite becomes difficult and puzzling due to the absence of classical findings. Electrophysiological tests in such cases give us important clue to reach at a definite diagnosis.
报告两例蛇咬伤后视力丧失的病例。
回顾性分析两个中心的病历，包括病史、检查结果、眼底细节及检查报告（视野、视网膜电图、视觉诱发电位和光学相干断层扫描）。
两例蛇咬伤患者在咬伤事件发生后1个月和3个月出现视力下降。其中1例患者视网膜电图b波异常及图形视网膜电图异常提示内视网膜功能障碍和神经毒性是眼底外观正常情况下视力丧失的原因。另一例患者b波呈阴性，提示视神经萎缩是连续性的（继发于视网膜中央动脉阻塞导致的内视网膜功能障碍）。
由于缺乏典型表现，蛇咬伤继发视力丧失的诊断在就诊较晚时变得困难且令人困惑。在此类病例中，电生理检查为明确诊断提供了重要线索。
