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Show Magnetic Resonance Imaging of Luxury Perfusion of the Optic Nerve Head in Anterior Ischemic Optic Neuropathy Oren S. Yovel, MD, Miriam Katz, MD, Hana Leiba, MD Abstract: A 49-year-old woman with painless reduction in visual acuity in her left eye was found to have nonarteritic anterior ischemic optic neuropathy (NAION). Fluorescein angiography revealed optic disc capillary leakage consistent with "luxury perfusion." Contrast-enhanced FLAIR magnetic resonance imaging (MRI) showed marked enhancement of the left optic disc. Resolution of the optic disc edema and the MRI abnormalities followed a similar time course. This report appears unique in documenting the MRI findings of luxury perfusion in NAION. Journal of Neuro-Ophthalmology 2012;32:256-258 doi: 10.1097/WNO.0b013e3182562afe © 2012 by North American Neuro-Ophthalmology Society Although magnetic resonance imaging (MRI) is the modality of choice in the assessment of various optic neuropathies, its role is limited in the diagnostic evaluation of NAION. The use of diffusion-weighted imaging (DWI) has shown promise in detecting optic nerve ischemia (1-3). We report a patient with NAION who developed luxury perfusion of the affected optic disc with marked enhance-ment of the optic nerve head on contrasted FLAIR MRI. CASE REPORT A 49-year-old woman presented with painless blurred vision in her left eye for 6 days. Her medical history included mild iron deficiency anemia and elevated cholesterol. Visual acuity was 20/25, right eye, and 20/30, left eye. While color vision was intact bilaterally, there was a left relative afferent pupillary defect. Slit-lamp examination and intraocular pressure were normal in both eyes. Automated visual field testing showed superior and inferior field loss in the left eye (Fig. 1). The right optic disc was normal with a cup-to-disc ratio of 0.1, and the left optic disc was swollen (Fig. 2). No other neurologic or systemic deficits were found. Fundus fluorescein angiography revealed hyperemia and leakage from the upper portion of the left optic disc (Fig. 3). Precontrast and postcontrast T1 MRI images of the orbits showed bulging of the left optic nerve head, and postcon-trast FLAIR revealed high signal within the left optic disc (Fig. 4). Three weeks later, visual acuity and visual fields were unchanged, but there was a slight decline in color vision in the left eye. The left disc was now pale with the resolution of edema. One month after the presentation, MRI revealed a decrease in the size and signal intensity of the left optic nerve head (Fig. 5). DISCUSSION Rizzo et al (4) examined the MRI findings in a cohort of patients with NAION using FLAIR and T2 images. They detected signal abnormalities in the orbital segment of the optic nerve in 5 of 32 patients, but none involving the optic disc. There have been few reports (1,2) of restricted diffu-sion of the optic disc using DWI in patients with NAION. It is in the setting of papilledema that increased signal abnormalities have been detected in the optic nerve head (5-7). These are often accompanied by other neuroimaging findings including flattening of the posterior sclera, vertical tortuosity of the orbital optic nerve, and empty sella (6). Luxury perfusion has been described as "a vascular response to ischemia characterized by dilation of blood ves-sels and increased perfusion in a region surrounding an infarct" (8). It consists of dilated blood vessels at the inter-face of infarct and normal tissue and has been described in the heart (9) and brain (10) and initially in NAION by Smith (11). Luxury perfusion in NAION is felt to be Department of Ophthalmology (OSY, HL) and Imaging Department (MK), Kaplan Medical Center, Rehovot, Israel; and Faculty of Medicine (HL), the Hebrew University, Jerusalem, Israel. The authors report no financial or conflicts of interest. Address correspondence to Hana Leiba, MD, Department of Oph-thalmology, Kaplan Medical Center, POB 1, 76100, Reovot, Israel; E-mail: leiba3@bezeqint.net.il 256 Yovel et al: J Neuro-Ophthalmol 2012; 32: 256-258 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. a vascular autoregulatory response to increase oxygenation in ischemic portions of the optic disc. In our patient, fluorescein angiography showed numer-ous dilated blood vessels in the upper portion of the affected disc, corresponding to the region of spared visual field. Luxury perfusion may have contributed to some preserva-tion of optic nerve function including visual acuity and inferior visual field. It is unclear why enhancement of the left optic disc was not seen on contrast-enhanced T1 MRI but was seen on FIG. 1. Automated visual field of the left eye showing nerve fiber bundle defects. FIG. 2. The right optic disc (A) is normal while the left disc (B) is swollen. FIG. 3. Fluorescein angiography during mid (A) and late (B) phases demonstrating intense fluorescence with dye leakage of the upper part of the left optic disc. Yovel et al: J Neuro-Ophthalmol 2012; 32: 256-258 257 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. FLAIR. It may be that there are unique properties of luxury perfusion resulting in contrast enhancement on FLAIR sequences. For example, Mathers et al (12) examined 105 patients with various diseases of the brain and found that superficial meningeal enhancement often was better seen with contrasted FLAIR versus T1 images. Whether the neuroimaging findings documented in our patient are unique to luxury perfusion in NAION awaits further study. REFERENCES 1. Al-Shafai LS, Mikulis DJ. Diffusion MRI imaging in a case of acute ischemic optic neuropathy. Am J Neuroradiol. 2006;27:255-257. 2. Klein JP, Cohen AB, Kimberly WT, Shah AS, Leiderman YI, Cestari DM, Dinkin MJ. Diffusion-weighted magnetic resonance imaging of bilateral simultaneous optic nerve infarctions. Arch Neurol. 2009;66:132-133. 3. Spierer O, Ben Sira L, Leibovitch I, Kesler A. MRI demonstrates restricted diffusion in distal optic nerve in atypical optic neuritis. J Neuroophthalmol. 2010;30:31-33. 4. Rizzo IJF III, Andreoli CM, Rabinow JD. Use of magnetic resonance imaging to differentiate optic neuritis and nonarteritic anterior ischemic optic neuropathy. Ophthalmology. 2002;109:1679-1684. 5. Manfré L, Lagalla R, Mangiamelli A, Lupo F, Giuffre G, Ponte F, Cardinale AE. Idiopathic intracranial hypertension: orbital MRI. Neuroradiology. 1995;37:459-461. 6. Brodsky MC, Vaphiades M. Magnetic resonance imaging in pseudotumor cerebri. Ophthalmology. 1998;105:1686-1693. 7. Seitz J, Held P, Strotzer M, Muller M, Volk M, Lenhart M, Djavidani B, Feurbach SJ. Magnetic resonance imaging in patients diagnosed with papilledema: a comparison of 6 high resolution T1- and- T2(*) -weighted 3- and 2- dimensional sequences. Neuroimaging. 2000;12:164-171. 8. Friedland S, Winterkorn JM, Burde RM. Luxury perfusion following anterior ischemic optic neuropathy. J Neuroophthalmol. 1996;16:163-171. 9. Braunwald E, Sobel BR. Coronary flow and myocardial ischemia. In: Braunwald E, ed. Heart Disease. 4th edition. Philadelphia, PA: Saunders, 1992:1162. 10. Heiss WD, Graf R. The ischemic penumbra-current opinion. Neurology. 1994;7:11-19. 11. Smith JL. Pseudohemangioma of the optic disc following ischemic optic neuropathy. J Clin Neuroophthalmol. 1981;5:81-89. 12. Mathers VP, Caldemeyer KS, Lowe MJ, Greenspan SL, Weber DM, Ulmer JL. Brain: Gadolinium-enhanced fast fluid-attenuated inversion-recovery MR imaging. Neuroradiology. 1999;211:257-263. FIG. 4. Axial (A) and sagittal (B) contrasted, fat-suppressed FLAIR images disclose hyperintense signal of the left optic nerve head. FIG. 5. One month later, axial contrasted, fat-suppressed FLAIR MRI shows diminished size and signal of the left optic disc. 258 Yovel et al: J Neuro-Ophthalmol 2012; 32: 256-258 Clinical Observation Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
