Should a Hypercoagulable Workup Be Performed on Young Patients with Nonarteritic Anterior Ischemic Optic Neuropathy?: Response

We would like to thank M. K. Kumar and his colleagues for sharing their experience regarding their patient's clinical presentation, Prothrombin G20210Amutation, and its proposed causative link to his development of non-arteritic anterior ischemic optic neuropathy (NAION) at the relatively young age of 47.

Letters to the Editor factors such as diabetes and hypertension, a hypercoagulable work-up is not only useful to protect the other eye from NAION, but given a longer life expectancy in these patients, it could also protect the patient from overall thromboembolic events anywhere else in the body, some of which could be life threatening. FIG. 1. A. Fundus image of the right eye showing crowded disc with absence of physiological cup. B. Fundus image of the left eye showing pallid disc edema. angiography showed LE delayed disc filling followed by late staining. A diagnosis of LE acute NAION was made. He was given a course of systemic steroids, and his vision improved in the LE. Although systemic steroids are controversial in management of NAION (2), we feel it is helpful in young patients (3). Since patient was neither diabetic nor hypertensive and a basic blood work-up including homocysteine levels was normal, a hypercoagulable work-up was performed and he was found to have homozygous mutation in factor II prothrombin gene G20210A. He was referred to a hematologist who recommended lifelong anticoagulation therapy. At 6-month follow-up, he had no recurrences in the LE with a visual acuity of 20/ 125 and his RE continued to be normal and unaffected. Hence, we agree with Dr. Francis that in a setting of a young patient ,50 years of age with no systemic risk Should a Hypercoagulable Workup Be Performed on Young Patients with Nonarteritic Anterior Ischemic Optic Neuropathy?: Response W e would like to thank M. K. Kumar and his colleagues for sharing their experience regarding their patient's clinical presentation, Prothrombin G20210A mutation, and its proposed causative link to his development of non-arteritic anterior ischemic optic neuropathy (NAION) at the relatively young age of 47. Indeed, there are other such case reports in the literature describing NAION occurring in patients with such mutations, without a previous history of thrombotic or ischemic events occurring elsewhere in the body. If there is a causal association, it is unclear to me why NAION would preferentially occur, without a history of much more common presentations of thrombosis. It is certainly compelling to prospectively anticoagulate a patient with NAION who is subsequently found to harbor this mutation; however, causa- Letters to the Editor: J Neuro-Ophthalmol 2020; 40: 442-443 Mani Karthik Kumar, MS Mansha Daswani, DNB Virna M. Shah, DO Department of Neuro-Ophthalmology, Aravind Eye Hospital & Postgraduate Institute of Ophthalmology, Coimbatore, India [e-mail] The authors report no conflicts of interest. REFERENCES 1. Francis CE, Patel VR. Should a hypercoagulable work-up be performed on young patients with nonarteritic anterior ischemic optic neuropathy? J Neuroophthalmol. 2019;39:523-528. 2. Saxena R, Singh D, Sharma M, James M, Sharma P, Menon V. Steroids versus no steroids in nonarteritic anterior ischemic optic neuropathy: a randomized controlled trial. Ophthalmology. 2018;125:1623-1627. 3. Hayreh SS, Zimmerman MB. Non-arteritic anterior ischemic optic neuropathy: role of systemic corticosteroid therapy. Graefes Arch Clin Exp Ophthalmol. 2008;246:1029-1046. tion is still not confirmed. We do know that venous thrombotic disease is much more common with the G20210A mutation than arterial thrombosis. Accordingly, if we were to assign causation in such cases, are we making the pathophysiological argument that venous thrombosis at the level of the laminar and prelaminar circulation subsequently leads to local arterial insufficiency and subsequent infarction? If we can agree on this potential mechanism, then the plausibility of causation and recommendations to routinely screen for all hypercoagulable states (venous and arterial) can be made for our NAION patients, regardless of age at presentation. Vivek R. Patel, MD University of Southern California, Roski Eye Institute, Keck School of Medicine, Los Angeles, California The author reports no conflicts of interest. 443 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.