Ophthalmologic outcome of direct and indirect carotid cavernous fistulas

Carotid cavernous fistulas (CCFs) can be classified as direct and indirect, depending on their flow rates and their etiology. Both forms can cause the same characteristic ophthalmological symptoms and signs. We analyzed these ocular characteristics and determined the prognostics factors associated with treatment outcome. Forty-seven patients with an angiographically confirmed diagnosis of CCF, a preoperative ophthalmic evaluation and at least one ophthalmic sign or symptom at the initial presentation were retrospectively evaluated. The patients were followed-up ophthalmically until the end of treatment, and the complications and the remaining ophthalmological signs and symptoms were then recorded. The patients' ages ranged from 13 to 89 years, with an average of 55.78 (±20.73) years, and a predominance of 28 female (57.8 %) patients. The patients with a direct CCF had a lower average age (p = 0.02). The most common symptoms were blurred vision in 17 (36.2 %) and proptosis in 37 (78.7 %) patients. Elevated intraocular pressure (IOP) was more prevalent in patients with an indirect CCF (p = 0.02). Thrill was more prevalent in patients with direct CCF (p = 0.01). The presence of an initial decrease of visual acuity at the first ophthalmic evaluation was significantly associated with the persistence of ocular symptoms after fistula treatment (odds ratio 3.33). In conclusion our study shows a slight difference in ophthalmic symptoms among patients with different types of fistula. Elevated IOP was significantly associated with indirect fistulas, whereas thrill was significantly associated with direct fistulas. The presence of an initial decrease of visual acuity was significantly associated with a worse ophthalmic prognosis.