Journal of Neuro-Ophthalmology, June 2011, Volume 31, Issue 2

Letters to the Editor

Magnetic Resonance Findings in the Pregeniculate Visual Pathways in Leber Hereditary Optic Neuropathy Ienjoyed reading the article by van Westen et al entitled ‘‘Magnetic resonance findings in the pregeniculate visual pathways in Leber hereditary optic neuropathy'' (1). However, I was perplexed by the discussion when the authors indicated that they referenced reports regarding optic nerve MRI abnormalities yet failed to cite 3 articles specifically written to address orbital MRI findings in Leber hereditary optic neuropathy (LHON). One was the first reported case of optic nerve enhancement on orbital MRI in LHON (2), another was a follow-up MRI report of the same patient 4 years later (3), and the third article docu-mented 3 patients with optic nerve and/or chiasmal enhancement in LHON (4). The patients reported by van Westen et al may have had optic nerve enhancement on contrast-enhanced orbital fat-suppressed MRI if they were imaged at presentation instead of 1 month later, as in case 1, or 6 months later, as in case 2. This report by van Westen et al continues to expand the spectrum of neuroimaging findings in patients with LHON. Michael S. Vaphiades, DO Departments of Ophthalmology, Neurology and Neurosurgery University of Alabama, Birmingham, Alabama [e-mail] REFERENCES 1. van Westen D, Hammar B, Bynke G. Magnetic resonance findings in the pregeniculate visual pathways in Leber hereditary optic neuropathy. J Neuroophthalmol. 2011;31: 48-51. 2. Vaphiades MS, Newman NJ. Optic nerve enhancement on orbital magnetic resonance imaging in Leber's hereditary optic neuropathy. J Neuroophthalmol. 1999;19:238-239. 3. Vaphiades MS, Newman NJ. Optic nerve enhancement in Leber hereditary optic neuropathy: four years later. J Neuroophthalmol. 2002;22:66-67. 4. Vaphiades MS, Phillips PH, Turbin RE. Optic nerve and chiasmal enhancement in Leber hereditary optic neuropathy. J Neuroophthalmol. 2003;23:104-105. Reply We appreciate the comments by Dr. Vaphiades but wish to emphasize that our primary focus was on optic tract changes on MRI in patients with LHON. We also look forward to new MRI findings in this patient population, which will hopefully provide greater insight into this disorder. Danielle van Westen, MD Department of Neuroradiology Center for Medical Imaging and Physiology Ska°ne University Hospital Lund, Sweden Choroidal Infarction or Cilioretinal Artery Occlusion in the Setting of Elevated Intracranial Pressure Due To Fulminant Idiopathic Intracranial Hypertension? Lamirel and colleagues (1) recently described a 20-year-old white woman with fulminant idiopathic intra-cranial hypertension (IIH) and a paracentral scotoma. Color fundus photographs and fluorescein and indocyanine green (ICG) angiography images are shown in the article. An area of whitened retina that also appears as a dark area on the ICG angiogram in the inferior macula is interpreted to be a choroidal filling defect from choroidal infarction respons-ible for the scotoma. Careful review shows that the interpretation of the images, and the resultant diagnosis, is likely incorrect. First, the color fundus photograph demonstrates an area of stark retinal whitening. This is most consistent with inner retinal infarction; outer retinal infarction from choroidal ischemia usually has a less dramatically white appearance and is often cream colored. Second, the infarction follows a retinal ar-teriole emanating from the optic nerve head. This arteriole is most likely responsible for the retinal infarction. The area of noninfarcted retina immediately adjacent and inferior to this artery is not perfused by this vessel and thus not in-farcted. On the other hand, the branches from this vessel that project toward the median raphe´ are surrounded by infarcted retina. The area of whitening corresponds to the area that these vessels perfuse. Third, the hypofluorescence on the ICG corresponds exactly to the area of opacified retina, but does not seem to correlate with any visible (or known) choroidal circulation pattern in this area. Thus, this hypofluorescence is most likely a relative blocking defect. It should also be noted that there is a relative blocking defect from the edematous retina surrounding the optic nerve. The arteriole responsible for the infarction is most likely a cilioretinal artery. A fairly large vessel perfusing part of the macula in this location, with a normal arcade vessel nearby, commonly is a cilioretinal artery. In the fluorescein Letters to the Editor 194 Letters to the Editor: J Neuro-Ophthalmol 2011; 31: 194-195 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. angiogram laminar flow phase image, the vessel in question appears to fluoresce more brightly than the other retinal vessels, suggesting that it was perfused earlier in the an-giogram, a characteristic of cilioretinal arteries. The ICG angiogram image does not show a definite connection of the artery adjacent to the infarcted retina to the central retinal artery, further suggesting that this is a cilioretinal artery. The pathophysiology of the cilioretinal artery occlusion in the setting of IIH may be similar to that in the setting of central retinal vein occlusion (CRVO). Hayreh et al (2) postulates that cilioretinal artery occlusion occurs due to increased intraluminal retinal capillary bed pressure re-sulting from the CRVO. It is possible that in this case presented by Lamirel et al (1), the abnormality is due to a similar pathophysiology, however, initiated by the IIH, due to optic nerve head congestion. Nonetheless, a case of cilioretinal artery occlusion in the setting of fulminant IIH has not been reported before in the literature. Colin A. McCannel, MD Department of Ophthalmology, Jules Stein Eye Institute UCLA Geffen School of Medicine, Los Angeles, California [e-mail] Supported by an unrestricted grant from the Research to Prevent Blindness and the Jules Stein Eye Institute. The author reports no conflicts of interest. REFERENCES 1. Lamirel C, Bruce BB, Newman N, Biousse V. Choroidal infarction in fulminant idiopathic intracranial hypertension. J Neuroophthalmol. 2010;30:167-168. 2. Hayreh SS, Fraterrigo L, Jonas J. Central retinal vein occlusion associated with cilioretinal artery occlusion. Retina. 2008;28:581-594. Reply It is indeed possible that the funduscopic appearance observed in our patient with severe papilledema from idiopathic intracranial hypertension might have been re-lated to a cilioretinal artery occlusion rather than to cho-roidal infarction. The distinction between these two entities can be difficult and was raised by our retina specialists when the patient was initially evaluated. However, it was concluded that choroidal infarction was more likely based on careful review of the retinal fluorescein and ICG video angiographies. The retinal arteriole seen on fundus photographs was normally perfused acutely. Nevertheless, as mentioned by Dr. McCannel, the pathophysiology of a cilioretinal artery occlusion would be similar to that of a choroidal infarction in the setting of severe papilledema and would have similar consequences for visual function. Vale´rie Biousse, MD Nancy J. Newman, MD Emory University School of Medicine Atlanta, Georgia [e-mail] Lupus Erythematosus Profundus and Enophthalmos I read the recent case report of lupus erythematosus profundus (LEP) by Kao et al (1) with a great interest. Kao et al concluded that ‘‘LEP should be considered in patients with a characteristic rash and orbital inflammation and may cause acquired enophthalmos.'' Indeed, in LEP, lobular lymphocytic infiltration and destruction of sub-cutaneous fat tissue are common and can occur in any part of body (2). Although ocular involvement in systemic lupus erythematosus is uncommon, Davies and Rao (3) suggested that ‘‘aggressive systemic therapy is often needed to control the disease.'' This clearly applies to LEP as well since the inflammatory reaction can lead to enophthalmos, as presented in this case. Viroj Wiwanitkit, MD Wiwanitkit House, Bangkhae, Bangkok, Thailand [e-mail] REFERENCES 1. Kao TY, Yoon MK, McCulley TJ, Ruben BS, Hwang TN. Acquired enophthalmos in lupus erythematosus profundus. J Neuroophthalmol. 2010;30:64-66. 2. Kato T, Nakajima A, Kanno T, Shinozaki M, Gono T, Ichida H, Masuda I, Kamatani N, Hara M. Clinical utility of computed tomographic scanning for the evaluation of lupus profundus in two patients with systemic lupus erythematosus. Mod Rheumatol. 2009;19:91-95. 3. Davies JB, Rao PK. Ocular manifestations of systemic lupus erythematosus. Curr Opin Ophthalmol. 2008;19:512-518. Reply We appreciate Dr. Wiwanitkit's interest in our re-port. We agree wholeheartedly with his assertion that orbital involvement in lupus profundus may be ac-companied by serious consequences but is, fortunately, an uncommon phenomenon. It should be treated in a timely manner and as aggressively as necessary to achieve control of the disease. Thomas Hwang, MD, PhD Department of Ophthalmology, Kaiser Permanente Redwood City, California Letters to the Editor Letters to the Editor: J Neuro-Ophthalmol 2011; 31: 194-195 195 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.