Indirect Carotico-Cavernous Fistula following Trivial Trauma Causing Secondary Glaucoma.

Dear Editor,

Secondary glaucoma due to raised episcleral venous pressure is rare and often poses a challenging situation for ophthalmologists. It can be idiopathic or can be seen in conditions such as thyroid-related orbitopathy, Sturge-Weber syndrome, and rarely carotico-cavernous fistula (CCF).[1]

The authors report about a 29-year healthy young male who presented with sudden onset of painless vision loss, drooping of the eyelid, and inability to move the eyeball in his right eye for 3 days. He had a history of trivial injury to his right eye with a wooden stick that he sustained while working in his workplace about 20 days back. On examination, his right eye revealed best-corrected visual acuity (BCVA) of 20/125, intraocular pressure (IOP) of 34 mmHg, relative afferent pupillary defect, complete ptosis, a healed scar below the right eyebrow associated with minimal proptosis, and absence of palpable bruit [Figure 1a]. The anterior segment showed scattered subconjunctival hemorrhages throughout the bulbar conjunctiva with minimal chemosis. There were congested deep vessels and total ophthalmoplegia [Figure 1b]. Dilated fundoscopy showed early optic disc pallid edema with tortuous and congested vessels in the right eye [Figure 2]. Magnetic resonance imaging with angiography demonstrated right-sided CCF with bilateral early filling of contrast in the cavernous sinus and dilated superior ophthalmic vein (right > left) [Figure 1e]. These clinical and diagnostic findings confirmed it as a case of CCF with secondary glaucoma. He was treated with anti-glaucoma medications and referred for urgent endovascular intervention. However, unfortunately, the patient deferred our advice. He returned after 6 months with complete resolution of ptosis and ocular motility but with secondary optic atrophy with BCVA 20/400 [Figure 1c and d]. The IOP at follow-up visit was however uncontrolled with topical antiglaucoma medications, and a trabeculectomy was advised. Although trivial trauma can initiate CCF in a predisposed individual with systemic hypertension or collagen vascular disease, it is unusual to present with a unilateral frozen globe in an otherwise healthy young male.[2] We believe the pathophysiology in our case may be due to a preexisting arteriovenous malformation which might have ruptured due to the trivial injury. Consequently, the increased episcleral venous pressure and vortex venous pressure resulted in raised IOP.[3] The differential diagnoses for this condition are viral conjunctivitis, anterior scleritis, thyroid-related orbitopathy, intraorbital bleed (posttraumatic or neoplastic), internal carotid artery aneurysm, or cavernous sinus syndrome.[4] Although spontaneous resolutions have been reported in 5%–10% of the patients, the risk stratifications of the patients should be performed to intervene early in the high-risk patients. The patient of CCF with associated neurologic deficits, progressive visual loss, altered mental status, intracerebral hemorrhage, and venous thrombosis deserve urgent attention to obliterate the fistulous tract.[5] Meyers et al. reported that endovascular intervention in such patients provides favorable outcome with low procedural morbidity.[5] Our case highlights the fact that early endovascular intervention in patients with optic nerve involvement could have prevented the onset of irreversible changes of glaucomatous optic atrophy.

Figure 1

(a) Clinical photograph showing right eye complete ptosis and a faint healed scar just below eyebrow. (b) Diffuse scattered subconjunctival hemorrhages and frozen globe in right eye. (c) Complete resolution of ptosis in the right eye. (d) Improvement in ocular motility in the right eye. (e) Magnetic resonance angiography showing dilated and engorged superior ophthalmic vein on right side (white arrow) and early contrast filling of cavernous sinus

Figure 2

Dilated fundus photo of the right eye showing temporal optic disc pallor, tortuous, and congested vessels

Declaration of patient consent

The authors certify that they have obtained consent from the patient for publication with his images and other clinical information. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.