J Korean Ophthalmol Soc.  2020 Jul;61(7):839-842. 10.3341/jkos.2020.61.7.839.

Presumed Ischemic Unilateral Oculomotor Nerve Palsy Developing after a Snake Bite

• Baek SC
• Kim WJ

• KMID: 2504328
• DOI: http://doi.org/10.3341/jkos.2020.61.7.839

Abstract

Purpose
We report a patient with presumed ischemic unilateral oculomotor nerve palsy developing after a snake bite on the right finger.
Case summary
A 58-year-old male visited our emergency department complaining of right ptosis and binocular diplopia that had developed after a snake bite. He had been bitten on a finger of the right hand by an unidentified snake about 6 hours prior to symptom onset. He lacked neurological symptoms such as headache, nausea, vomiting, or an altered consciousness level. The right hand exhibited severe swelling, oozing, and inflammation. The visual acuity was 20/25 in both eyes. Ptosis was evident in the right eye. Both pupils responded normally to light and near stimulation. Extraocular examination revealed movement limitations in all right-eye gaze fields except abduction. A serological test revealed coagulopathy. Pyridostigmine was prescribed, but the ocular symptoms did not immediately improve; however, they did improve gradually during follow-up. At 8 months after the initial visit, the patient exhibited an ortho primary gaze with an adduction limitation of -1. No aberrant regeneration was apparent.
Conclusions
Unilateral oculomotor nerve palsy can develop after a snake bite, possibly attributable to microvascular ischemia caused by coagulopathy.

Keyword

Blood coagulation disorders; Diplopia; Oculomotor nerve disease; Snake bites