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Figure 1 Figure 2a Figure 2b Photos courtesy of: Prof. Dinesh Selva, Adelaide, Australia Used with permission. Not to be reproduced.

A 65-year-old female presented with a red eye and discomfort in her left eye for the past 4 months. The patient was doing well systemically and there was no history of trauma. On examination, right eye (RE) vision was 6/6 and left eye (LE) was counting fingers at 1m. Left eye pupil showed relative afferent pupillary defect. Hertel’s exophthalmometry was 20 mm in the RE and 22mm in the LE. Extraocular movements were full bilaterally. Left eye slit lamp biomicroscopy revealed dilated and corkscrew-shaped conjunctival vessels [Figure 1]. Anterior segment was within normal limits except 18mmHg intraocular pressure (IOP) in RE and 24mmHg IOP in LE. Left eye fundus examination showed signs suggestive of central retinal vein occlusion. Right eye examination was normal. Imaging results are as shown above in Figure 2a and 2b.

1.	What is the clinical diagnosis?
	c -- carotid cavernous fistulas (CCF)
2.	What are the usual signs on imaging?
	d -- all of the above
3.	Treatment options would be:
	d -- all the above, depending upon the severity of symptoms

Mild proptosis, corkscrew conjunctival vessels, and ocular hypertension are suggestive of carotid cavernous fistulas (CCF). No history of significant trauma means a fistula spontaneously developed. On imaging, enlarged extraocular muscles and dilated superior ophthalmic vein are diagnostic of CCF.