A 55-year-old woman developed bilateral vision loss due to an ischemic stroke after a Russell’s viper bite
A Sri Lankan woman presented in the ER with the complaint of a Russell’s Viper bite. It is a common species across Sri Lanka and South India. The woman did not have obvious bleeding defects. However, her prolonged whole blood clotting test (WBCT) suggested coagulopathies. The coagulopathies were due to venom poisoning. The woman had a swollen bite site (edema) and blood in the urine (hematuria). The doctors gave her anti-venom serum, which alleviated her initial symptoms. But, after three hours of the treatment, she complained of blurred vision.
Suggestive of Cortical Blindness
The doctors did a slit lamp examination. Her retinae were normal. But her visual acuity had dropped down to the level of light perception only. This finding suggests cortical blindness.
The doctors performed a CT scan to look for any pathologies in her brain’s cortex. Infarcts were seen in both her visual cortices. However, there were no hemorrhages. Supportive treatment resolved the coagulopathies. In addition to repeating clotting tests, which were normal, the doctors also took her blood samples for estimation of lipids, sugar, and creatinine. All tests were normal, except her D-dimer levels, which had slightly elevated.
Treatment and Recovery
The doctors managed her venom-specific symptoms with timely administration of anti-venom serum. Due to her cortical infarction, conservative treatment and after-care guidance were given.
On a follow-up after three months, there was an improvement in her vision. The test was done with gross visual acuity, ‘counting fingers at a distance of 1 meter’. The improvement in her vision highlighted the importance of constant monitoring and rehabilitative care along with anti-venom therapy.
An Unusual Case?
Russell’s viper bites are very common in Sri Lanka. They usually result in instant coagulopathies and neurotoxic manifestations. But they rarely cause an ischemic stroke.
Furthermore, we have never seen cortical blindness develop after the viper’s bite. This woman is probably the first victim to develop bilateral vision loss due to cortical infarct after Russell’s viper bite.
Reference: Subasinghe, C.J., Sarathchandra, C., Kandeepan, T. et al. Bilateral blindness following Russell’s viper bite – a rare clinical presentation: a case report. J Med Case Reports 8, 99 (2014). https://doi.org/10.1186/1752-1947-8-99