West Nile Virus Chorioretinitis: First Case with Ocular Involvement in Türkiye

Area of Science:

• Ophthalmology
• Infectious Diseases
• Virology

Background:

• West Nile virus (WNV) is a mosquito-borne flavivirus that can cause neurological disease.
• Ocular manifestations of WNV infection, such as chorioretinopathy, are rare but can lead to significant visual impairment.

Purpose of the Study:

• To report a case of bilateral WNV chorioretinopathy presenting with severe visual loss.
• To highlight the clinical features, diagnostic methods, and treatment outcomes of WNV chorioretinopathy.

Main Methods:

• A 59-year-old man with acute visual loss underwent comprehensive ophthalmologic examination, including fundoscopy and autofluorescence imaging.
• Systemic evaluation included WNV polymerase chain reaction and serological testing (IgM and IgG antibodies).
• Brain MRI was performed to rule out central nervous system involvement. Treatment with intravitreal ranibizumab was administered for macular edema.

Main Results:

• The patient presented with severe vision loss in the right eye and characteristic fundus lesions, including track-like hyperautofluorescent lines.
• WNV IgM and IgG antibodies were detected, confirming bilateral WNV chorioretinopathy.
• Following treatment, visual acuity improved, and hyperautofluorescent lesions resolved, although optic disc pallor persisted in the affected eye.

Conclusions:

• Clinicians should consider WNV chorioretinopathy in patients with characteristic fundus findings and a history of febrile illness.
• Prompt diagnosis and appropriate treatment can lead to favorable visual outcomes in WNV chorioretinopathy.