Carotid cavernous fistula is an abnormal communication between the carotid
arterial system and the cavernous sinus. We present an interesting, rare case of
bilateral spontaneous ‘Barrow type- C’ fistula treated presumptively as
conjunctivitis. A 66 year old patient presented in the eye casualty at North
Devon District Hospital in January 2016, referred from her General practitioner
complaining of bilateral red eyes. She was found to have large, prominently
diffused and engorged scleral blood vessels on both sides along with raised
intraocular pressures of 26mm of Hg bilaterally. The patient was diagnosed with
an indirect carotic cavernous fistulas bilaterally in view of the clinical and
radiology findings. Barrow type - C dural fistulas were reported to be seen
bilaterally on radiology findings. Patient was referred for interventional
treatment to the closest neurosurgical center where she had four failed attempts
of coil embolization after which she was referred to a second neurosurgery
center at Bristol where she underwent successful coil catheterization as the
treatment for her carotid cavernous fistula. Indirect carotid cavernous fistula
most commonly occur spontaneously. Bilateral spontaneous indirect carotid
cavernous fistula is a very rare diagnosis and and there are very few cases
reported in the literature without an underlying etiology or a known cause like
Ehlers -Danlos syndrome or diabetes mellitus. Bilateral spontaneous carotid
cavernous fistulas are difficult to diagnose due to mild symptoms and no history
of trauma. We conclude that carotid cavernous fistulas are a threat to the
vision if left untreated due to delayed diagnosis. We recommend considering
bilateral carotid cavernous fistula as a differential diagnosis in patients with
an ongoing history of red eyes or those unresponsive to conventional topical
treatment for conjunctivitis like symptoms.