Intraocular Pressure in the Eyes of Patients With Carotid-Cavernous Fistulas: Profile, Intereye Asymmetry, and Treatment Outcomes.

PRECIS: Secondary ocular hypertension (OHT) is common in carotid-cavernous fistulas (CCFs). Management of elevated intraocular pressure (IOP) is possible with a multidisciplinary approach. The ipsilateral normal eyes may have higher IOP than the contralateral eyes. PURPOSE: To study the IOP profile of the eyes of patients with a CCF, treatment outcomes for elevated IOP, and intereye IOP asymmetry in the eyes with normal IOP. METHODS: This was a retrospective case series. A total of 64 eyes of 60 patients with digital subtraction angiography-proven CCF diagnosed from the year 2000 to 2016 were included. The demographics, clinical features, management, and outcomes were recorded. The primary outcome included understanding of the cause of elevated IOP. The secondary outcomes included comparison of the IOP between contralateral eyes and ipsilateral normal eyes (IOP <21 mm Hg) and management outcomes for elevated IOP. RESULTS: The mean age of the patients was 45.6±18.2 years. In the study population, 70% of the patients were males. Indirect CCF was present in 55% of the eyes. It was found that 64.06% (n=41) of the eyes had elevated IOP, glaucoma, or were glaucoma suspects. Among all the eyes, 40.62% (n=26) of the eyes had secondary OHT due to elevated episcleral venous pressure, whereas 7.81% (n=5) of the eyes had secondary open-angle glaucoma. The mean IOP was higher in the ipsilateral eyes than in the other eyes (22.95±7.1vs. 15.11±2.99 mm Hg; P<0.001). The mean IOP in the ipsilateral normal eyes was higher than that in the contralateral eyes, with a mean difference of 2.92±2.29 mm Hg (confidence interval of the mean difference: 1.90-3.94 mm Hg; P<0.0001). IOP reduction (<21 mm Hg) was achieved in 70.7% of the patients following CCF management with intermittent carotid massage, endovascular treatment, IOP-lowering medications, or a combination among these. CONCLUSIONS: Secondary OHT due to elevated episcleral venous pressure was more common than secondary open-angle glaucoma. Ipsilateral normal eyes had higher IOP than contralateral eyes. IOP-lowering agents and management of CCF resulted in IOP control in most patients.