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Abstract #15970 Published in IGR 2-3
Neovascular glaucoma and ocular ischemic syndrome.
Gross RJournal of Glaucoma 2000; 9: 409-12
In this "cases in Controversy" series a rather extraordinary case of neovascular glaucoma is discussed by the section editor Ronald Gross and two experts: Jean Philippe Nordmann and Christopher Girkin. The case is a 42 year old white man with painless loss of vision in his right eye. He has no significant medical problems. His visual acuity is less than 0.1 in the affected eye. There is neovascularisation at the pupillary border. Intraocular pressures are 17 mmHg and 20 mmHg respectively. Both angles are open but bloodvessels are seen crossing the scleral spur onto the trabecular meshwork in all four quadrants of the angle of the right eye. In fundo one could see arteriolar narrowing in each eye and an occasional peripheral retinal hemorrhage in the right eye. On fluoresceine angiography mild retinal ischemia is seen in the right eye. The experts are asked about the differential diagnosis, laboratory investigations and treatment.Nordmann comments that in the absence of diabetes mellitus and central retinal vein occlusion the most common cause of retinal ischemia and consequent neovascular glaucoma is ocular ischemic syndrome, usually caused by carotid artery occlusive disease. In the current case the carotid artery obstruction is associated with decreased aqueous humor production with normal or even low IOP. He feels that because of the underlying ischemic retinopathy panretinal photocoagulation is necessary. He does not believe that goniophotocoagulation is successful. Endarterectomy restores ciliary body perfusion and the production of aqueous humor normalizes in the presence of reduced aqueous outflow through a neovascular membrane. This results in increase of IOP. Treatment of the situation consist of the usual medical treatment in addition to panretinal photocoagulation and even panretinal cryotherapy. If this is not sufficient a guarded filtration procedure with an antifibrotic agent may be needed. If that also fails transscleral ciliary destruction can be performed. The second expert, Girkin comments that this patient depicts the classic findings found in advanced ocular ischemic syndrome secondary to chronic hypoperfusion. He comments on the differential diagnosis. Medical examination should include a serum lipid profile and carotid imaging studies. It is noteworthy that this patient is relatively young for the ocular ischemic syndrome. In addition to the comments made by the first author he states that trabeculectomy in the presence of an active anterior segment neovascularisation is not very successful. He will start with transscleral diode laser treatment. Once the neovascularisation has regressed the chances of filtering surgery are better. The section editor Gross rightly comments on the frustrating task of the treating ophthalmologist because of the difficulty of adequate treatment and the disappointing visual results. He warns that one should not be misled by the relatively normal appearance of the retina and the lack of elevated IOP. The causes of retinal ischemia are discussed. Anterior segment neovascularisation is thought to occur due to diffusion of angiogenic factor. He feels that filtration surgery with antifibrotic after panretinal photocoagulation has a reasonable successrate. He is also in favor of tube shunt implantation when necessary.
Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
Classification:
9.4.5.1 Neovascular glaucoma (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders > 9.4.5 Glaucomas associated with disorders of the retina, choroid and vitreous)
