A 31-year-old Malay gentleman presented to our Ophthalmology clinic with history of progressive bulging of the left eye associated with redness and pain for 2 months. He has no known medical illness although his blood pressure was reported slightly abnormal on his last visit to general practitioner. For the past five years, he has been having recurrent nasal blocked which resolved by nasal decongestion spray that he bought over the counter. He started to have recurrent headache since his last episodes of nasal congestion which was three months prior to his visit to us. In the past one month, he has reduced vision in the left eye and noticed double vision on turning to the left.
His visual acuity in the left eye was 6/18 and 6/9 in the right eye. Ocular examination revealed congestive nonpulsating 7
mm exophthalmos of the left eye, measured by Hertel exophthalmometer (). There was no restriction of eye movements in all direction of gazes but there was diplopia in left lateral gaze. There was no restriction of eye movements in all direction of gazes. At primary gaze intraocular pressure was 21
mmHg in the right and 29
mmHg in left eye, with no difference in other gaze. Fundoscopy of the left eye showed slightly dilated and tortuous retinal vessels (). The right fundus was normal. There was no optic disc swelling on either eye. OCT pupillometry was normal. Colour vision and visual field on each eye were normal. Systemic examinations were normal except a borderline blood pressure. There was no sign of thyroid disease. Cranial nerves were intact. He is moderately overweight but there was no sign of increased intracranial pressure.
Congestive nonpulsating exophthalmos of the left eye.
Dilated and tortuous conjunctival vessels.
CT scan was performed and showed right temporal arteriovenous malformation with right middle cerebral artery as feeding artery. The left superior ophthalmic vein was tortuous and dilated measuring 0.9
mm in diameter. The left cavernous sinus was enlarged (). Extraocular muscles of left eye were relatively larger than the right eye. MRA and carotid four vessels angiogram confirmed right temporal arteriovenous malformation with a nidus of 3.8
cm × 2.5
cm (). Arterial feeder is middle cerebral artery with no supply from external carotid artery. There was no aneurysm and no carotid-cavernous fistula. The right temporal AVM is grade 4 based on Spetzler Martin grading system. There was severe venous hypertension with most of the intracranial drainage being via left cavernous sinus. Venous drainage of the AVM is via the dilated and tortuous right temporal cortical vein into the right transverse sinus. There was a tight stenosis at the right sigmoid sinus. Hence from right transverse sinus, there was retrograde flow into superior sagital sinus and straight sinus that reach the left cavernous sinus and finally into the left superior orbital vein and left petrosal sinus. Left sigmoid sinus is occluded.
Enlarged cavernous sinuses and dilated left superior ophthalmic vein.
MRA confirmed right temporal arteriovenous malformation with no carotid-cavernous fistula.
His proptosis dramatically improved following successful embolisation of the arteriovenous malformation. Follow-up after one year showed that the uncorrected visual acuity of 6/9 improved to 6/6 after refraction. Following cessation of antiglaucoma eye drops, his IOP remains between 14
mmHg and 16
mmHg on several visits. The proptosis has completely resolved.