A case of normal tension glaucoma associated with Buerger's disease.

Open angle glaucoma, a slowly progressive optic atrophy, is clinically characterized by visual field defects corresponding to excavation of the optic disc, called glaucomatous cupping. Open angle glaucoma is further divided into primary open angle glaucoma caused by elevated intraocular pressure (higher than the normal limit of 21 mmHg), and normal tension glaucoma, in which intraocular pressure is in the normal range. Here we report a case of normal tension glaucoma associated with Buerger's disease, also known as thromboangiitis obliterans, which causes systemic blood flow disturbance. A 66-year-old man suffering from Buerger's disease for 10 years was diagnosed as having branch retinal artery occlusion in his left eye. He was referred to our clinic due to progressive visual field disturbance in that eye. Ophthalmologic examinations revealed occlusion in the infero-temporal retinal artery in the left eye, and glaucomatous cupping, normal intraocular pressure, retinal vessel tortuosity and retinal arteriosclerosis in both eyes. Visual field examination revealed decreased retinal sensitivities in the areas within the visual field arches above and below fixation from the blind spot to the median raphe, corresponding to the arcuate retinal nerve fibers comprising the Bjerrum areas and the area corresponding to the retinal artery occlusion. Buerger's disease is characterized by the development of segmental thrombotic occlusions and vasospasm of the medium and small arteries. Our case suggests that the blood flow disturbance due to arteriosclerosis, thrombotic occlusions and vasospasm associated with Buerger's disease might affect the ophthalmic circulation system, thereby contributing to the etiology of normal tension glaucoma.