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Abstract #5750 Published in IGR 2-1
Glaucoma associated with elevated episcleral venous pressure (cases in controversy)
Greenfield DSJournal of Glaucoma 2000; 9: 190-194
The editor Davis Greenfield discusses glaucoma associated with elevated episcleral pressure with two experts: S. Fabian Lerner and Brian Lee. The case presented is a 43-year-old woman with uncontrolled glaucoma in her left eye. The left lid fissure is slightly wider and there is a 2-mm proptosis. There are dilated episcleral and conjunctival vessels in the left eye. The pressure is 41 mmHg. On gonioscopy, there is blood in the Schlemm's canal of the left eye. The posterior segment shows diffuse enlargement of the left cup and moderate vascular tortuosity in the left eye. The present treatment is latanoprost, timolol and dorzolamide. Laser trabeculaoplasty has been tried but was unsuccessful. The first discussant, Fabian Lerner, divides episcleral venous pressure into three groups: venous obstruction, obstruction of the superior vena cava and unknown etiology. In this relatively young woman, thyroid ophthalmopathy is one of the more frequent options. Computed tomography may be helpful. A second option is a carotid sinus fistula. The idiopathic type of EVP is a diagnosis of exclusion. It is this author's impression that this type is relatively frequent. As treatment, he would perform a filtering procedure with the necessary precautions as for instance the use of two posterior sclerotomies. He would further use a viscoelastic and tight suturing of the scleral flap followed by suture lysis. The second discusser is Brian Lee. As far as the diagnosis is concerned, he uses the same subdivision. Cases of venous obstruction include retrobulbar tumor, thyroid ophthalmopathy, superior vena cava syndrome, congestive heart failure and thrombosis of the cavernous sinus or orbital veins. Causes of arteriovenous anomalies include carotid-cavernous sinus fistula, orbital varix, Sturge-Weber syndrome and dural-cavernous sinus fistula. As necessary work-up, this author considers orbital ultrasonography or even MRI. If this does not help, carotid angiography or contrast enhanced magnetic resonance angiography may be appropriate. The underlying cause should be treated. Even if that is done the IOP may remain elevated, according to this author. When filtering surgery is considered the well-known risk of severe choroidal effusion or suprachoroidal hemorrhage is present. The procedure of choice is a standard guarded trabeculectomy. Prophylactic posterior sclerectomies could be considered. The adjunctive antifibrosis agent of choice is 5 fluorouracil in order to prevent prolonged hypotony postoperatively in a patient who does not require extremely low IOPs. the scleral flap is sutures tightly with the intention to perform suture lysis later. The editor of this section reviews the anatomy associate with orbital venous drainage. For him the most likely diagnoses thyroid disease, Sturge-Weber syndrome but most likely low-flow dural-sinus fistula which usually occurs in middle-age or elderly women. To the diagnostic evaluation, he adds color Doppler imaging and subtraction angiography. Up to 50% of patients with dural sinus fistula will experience spontaneous closure. Medical treatment as long as possible needs therefore be considered. In the case of elevated EVP, pilocarpine and latanoprost are not particularly effective. Similarly, laser trabeculoplasty is generally ineffective in this disease. Definite treatment of the fistula should be performed. This author also considers standard trabeculectomy with the necessary precautions.
Classification:
9.4.9 Glaucomas associated with elevated episcleral venous pressure (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders)
