Intraocular Pressure in the Eyes of Patients With Carotid-Cavernous Fistulas: Profile, Intereye Asymmetry, and Treatment Outcomes Mona Khurana, MS,* Md. Shahid Alam, MS,† Shantha Balekudaru, DNB,* Lingam Vijaya, MS, FRCS,* Manapakkam B. Madhuri, DNB, MS,* Swatee V. Halbe, MD,‡ Veena O. Noronha, MD,§ Ronnie J. George, MS,* and Bipasha Mukherjee, DNB, MS† 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 demo- graphics, 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. Key Words: carotid cavernous ﬁstula, glaucoma, ocular hyper- tension, neovasuclar glaucoma, intraocular pressure, asymmetry (J Glaucoma 2019;28:1074–1078) C arotid-cavernous ﬁstulas (CCFs) are abnormal vascular shunts. Blood ﬂows directly or indirectly from the carotid artery into the cavernous sinus, leading to elevated venous pressure within the sinus. 1,2 CCFs are classiﬁed based on their communication with the carotid artery into direct (Barrow type A) and indirect (Barrow type B, C, or D) types. 3 In addition, they are classiﬁed based on their hemodynamic properties into high-ﬂow and low-ﬂow CCFs and based on their etiology as traumatic and spontaneous CCFs. 3 The cavernous sinus contains important structures, such as the oculomotor nerve, trochlear nerve, branches of the trige- minal nerve, abducens nerve, and internal carotid artery (ICA). Therefore, ocular symptoms and signs are often the presenting features of CCFs. 1,2 The spectrum of clinical features depends on the arterial ﬂow and venous pressure. Thus, the clinical presentation may range from subtle signs, such as mild redness and blood in the Schlemm’s canal on gonioscopy, to severe features, such as chemosis, diplopia, proptosis, secondary angle closure (Fig. 1A–C), central retinal vein occlusion, and retinal venous tortuosity secondary to venous stasis. 4–9 In both indirect and direct CCFs, elevated intraocular pressure (IOP) can be secondary to multiple mechanisms, such as elevated episcleral venous pressure (EVP) and secondary angle closure. 1,2,5–13 Neovascularization and subsequently neovascular glaucoma (NVG) may result from decreased perfusion and ischemia. 14–16 Vision loss is reported in 20% to 30% of the cases of dural CCFs. 1,2,17,18 Retinal changes, corneal changes, glaucomatous optic neuropathy, ischemic optic neuropathy, and sequelae of CCF management may cause some degree of visual impairment in 60% to 90% of the patients with CCF. 19,20 Visual impairment may be reversible or irreversible, depending on the cause. Blindness is usually irreversible and persists even after the successful management of CCF. Rarely, it is reversible following timely intervention. 21–23 Glaucoma can cause irreversible blindness, especially in cases of untreated CCF. Elevated IOP is a known risk factor for glaucoma. Ishijima et al 24 reported elevated IOP in 64.3% of the patients with CCF. Henderson and Schneider 9 reported elevated IOP and/or glaucoma in 35% DOI: 10.1097/IJG.0000000000001392 Received for publication May 11, 2019; accepted October 13, 2019. From the *Smt. Jadhavbai Nathamal Singhvi Glaucoma Services, Sankara Nethralaya Medical Research Foundation; †Department of Orbit Oculoplasty, Reconstructive and Aesthetic Services, Sankara Nethralaya Medical Research Foundation; ‡Apollo Speciality Hospitals Vanagaram; and §VRR Scans, Chennai, Tamil Nadu, India. Disclosure: The authors declare no conﬂict of interest. Reprints: Mona Khurana, MS, Sankara Nethralaya Medical Research Foundation, 18/41 College Road, Chennai 600 006, Tamil Nadu, India (e-mails: mona.insight@gmail.com; drmak@snmail.org). Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website, www. glaucomajournal.com. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. ORIGINAL STUDY 1074 | www.glaucomajournal.com J Glaucoma  Volume 28, Number 12, December 2019 Copyright r 2019 Wolters Kluwer Health, Inc. All rights reserved.