Purpose

Painful proptosis with a red eye has a broad differential. Carotid cavernous fistula (CCF) is a rare but important diagnosis that is frequently delayed, as early features may mimic more prevalent orbital disease. This case highlights the clinical and radiological cues that should prompt consideration of CCF in patients with acute orbital congestion, with the aim of supporting earlier recognition and improved outcomes.

---

Methods

An 84-year-old male presented with a painful, proptosed, red eye associated with partial ophthalmoplegia. Initial clinical assessment raised several differential diagnoses, including orbital cellulitis, thyroid eye disease, idiopathic orbital inflammatory disease, and orbital malignancy. A non-contrast CT was performed as part of the initial workup demonstrating a potential, mild distention of the superior ophthalmic vein. Subsequent CT angiography revealed the underlying CCF.

---

Results

Plain CT demonstrated a dilated superior ophthalmic vein, an important radiological clue that prompted urgent vascular imaging. Subsequent CTA confirmed a direct cavernous fistula. Following multidisciplinary discussion, the patient was deemed unsuitable for intervention due to frailty, age and significant co-morbidity. A shared decision was made favouring conservative management, with the patient discharged following appropriate counselling regarding the risks and prognosis of his condition.

---

Conclusion

This case emphasises the importance of considering CCF in the differential diagnosis of a painful red eye with proptosis and ophthalmoplegia. As clinical features may overlap with more common orbital conditions, delayed diagnosis can occur without careful assessment and appropriate imaging. A dilated superior ophthalmic vein on non-contrast CT is a key radiological red flag warranting urgent vascular imaging. Equally, this case reinforces the value of early multidisciplinary team involvement in shared decision making for complex surgical cases, where the most appropriate management may be conservative rather than interventional.

---

Additional Authors

First name	Last name	Base Hospital / Institution
Mark	Awad	Royal Bournemouth Hospital
Owen	Anderson	Royal Bournemouth Hospital

↑ Back to top