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Show Primary Iris Neovascularization in Neurofibromatosis Type 1 Conor P. Mulholland, MBBS, FRCOphth, Jack Rootman, MD, FRCSC, Christopher J. Lyons, MBBS, FRCS, FRCSC Anterior segment neovascularization may occur in neurofibromatosis type 1 (NF1) secondary to optic nerve glioma or carotid stenosis (1,2). We report a case of primary anterior and posterior segment neovascularization and neovascular glaucoma occurring in NF1 in the absence of detectable vascular abnormality or glioma. A 14-year-old boy with NF1 presented with an episode of total loss of vision in the right eye lasting 20 minutes. Visual acuity was 20/20 in both eyes. Slit-lamp examination showed conjunctival injection, Lisch nodules, and iris ne-ovascularization of the right eye (Fig. 1). The intraocular pressure was 45 mm Hg. Neovascular closure of the angle was confirmed by gonioscopy. There was no relative afferent pupillary defect, and color vision testing was normal. Ophthalmoscopy showed widespread arteriolar narrowing and venous dilatation with an area of vitreous hemorrhage overlying peripheral retinal neovascularization. Digital ophthalmodynamometry showed that the right central retinal arterial pressure was significantly lower than the left. Examination of the left eye was normal. Brain and orbit CT and CT angiography, including the vessels of the neck, were normal. Carotid doppler ultraso-nography and cardiac examination were normal. Retinal fluorescein angiography showed peripheral retinal neo-vascularization. There was no evidence of retinal artery or vein occlusion. Cryotherapy was applied to the areas of peripheral retinal vascular closure. Despite regression of the anterior chamber and retinal neovascularization, an Ahmed valve was required to control the intraocular pressure. One year after the initial presentation, the visual acuity remained stable at 20/20 in each eye. Shuto and Yamamoto (3) described a case of ocular ischemia in NF1 in association with hypoplasia of the in-ternal carotid artery. Barral and Summers (2) described a boy with NF1 and absence of the right carotid circulation who developed ocular ischemia at an age of 19 months. However, isolated ocular neovascularization in the absence of optic nerve glioma or carotid abnormality is rare. There have been 3 reports of isolated retinal ischemia occurring in young adults with NF1 (4-6) and 2 in children with NF1 (7,8). However, none had the anterior segment neo-vascularization and secondary glaucoma observed in this case. We acknowledge that the raised intraocular pressure might have been caused by outflow channel dysgenesis as-sociated with NF1. FIG. 1. Iris neovascularization and Lisch nodules are evident in the right eye. Royal Victoria Hospital (CPM), Belfast, United Kingdom; Department of Ophthalmology (JR, CJL), British Columbia Child-ren's Hospital, Vancouver, British Columbia. Address correspondence to Christopher J. Lyons, MBBS, FRCS, FRCSC, Department of Ophthalmology, BC Children s Hospital, 4480 Oak Street, Vancouver, British Columbia, Canada V6H 3V4; E-mail: clyons@cw.bc.ca 340 Mulholland et al: J Neuro-Ophthalmol 2010; 30: 340-341 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Patients with NF1 have a propensity to develop aneur-ysms, stenoses, vascular occlusions, pseudoaneurysms, and fistulas (9). Histopathologically, small vessels may be affected by scattered nodular smooth muscle lesions that arise from the walls of the arteries and obstruct flow (10). Abnormal vascular maintenance and repair may also contribute to the pathogenesis of NF-related vasculopathy with abnormalities of neurofibromin expression leading to altered smooth muscle cell responses to endothelial signals (11). Given the absence of angiographic or ultrasonographic evidence of larger vessel occlusion in our patient, it is likely that the ocular ischemia was caused by small vessel NF-related vasculopathy. REFERENCES 1. Buchanan TA, Hoyt WF. Optic nerve glioma and neovascular glaucoma: report of a case. Br J Ophthalmol. 1982;66: 96-98. 2. Barrall JL, Summers CG. Ocular ischemic syndrome in a child with moyamoya disease and neurofibromatosis. Surv Ophthalmol. 1996;40:500-504. 3. Shuto T, Yamamoto I. Ocular ischemia with hypoplasia of the internal carotid artery associated with neurofibromatosis type 1. Acta Neurochir. 2000;142:353-354. 4. Lecleire-Collet A, Cohen SY, Vignal C, Gaudric A, Quentel G. Retinal ischemia in type 1 neurofibromatosis. Br J Ophthalmol. 2006;90:117. 5. Kadoi C, Nagaki Y, Hayasaka S. Unilateral peripheral retinal vascular occlusion in a young Japanese woman with neurofibromatosis-1. Retina. 2003;23:541-543. 6. Tholen AM, Messmer EP, Landau K. Peripheral retinal vascular occlusive disorder in a young patient with neurofibromatosis 1. Retina. 1998;18:184-186. 7. Moadel K, Yannuzzi LA, Ho AC, Ursekar A. Retinal vascular occlusive disease in a child with neurofibromatosis. Arch Ophthal. 1994;112:1021-1023. 8. Mosin IM. Ischemic lesions of the retina in a child with neurofibromatosis 1. Vestn Oftalmol. 1998;114:46-48. 9. Friedman JM, Arbiser J, Epstein JA, Gutman DH, Huot SJ, Lin AE, McManus B, Korf BR. Cardiovascular disease in neurofibromatosis 1: report of the NF1 cardiovascular task force. Genet Med. 2002;4:105-111. 10. Greene JF Jr, Fitzwater JE, Burgess J. Arterial lesions associated with neurofibromatosis. Am J Clin Pathol. 1974; 62:481-487. 11. Hamilton SJ, Friedman JM. Insights into the pathogenesis of neurofibromatosis 1 vasculopathy. Clin Genet. 2000;58: 341-344. Clinical Observation Mulholland et al: J Neuro-Ophthalmol 2010; 30: 340-341 341 Copyright © North American Neuro-Ophthalmology Society. 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