A case of permanent vision loss due to a carotidcavernous fistula: importance of early diagnosis.

A 97-year-old female presented with spontaneous acute-onset palpebral hyperemia and edema of the right eye that had progressively worsen over the previous three days. These signs did not suggest possible carotid-cavernous fistula until a second examination 72 h later, during which the patient exhibited significant progression. Despite embolization, the patient exhibited sustained corneal edema, clots, and turbidity in the aqueous humor, which resulted in permanent visual loss. A greater level of clinical suspicion for possible carotid-cavernous fistula is warranted on initial presentation of palpebral hyperemia and edema to prevent possible irreversible vision loss.