Papilledema and Extensive Dural Sinus Thrombosis Due to JAK2 Mutation: Response

Letters to the Editor Iris Ben-Bassat Mizrachi, MD Neuro-Ophthalmology Unit, Sheba Medical Center, Tel Hashomer, Israel Papilledema and Cerebral Venous Sinus Thrombosis Due to JAK2 Mutation W e read with interest the case report by Kisilevsky et al (1) about a patient with cerebral venous sinus thrombosis (CVST) and presence of JAK2V617F mutation. It is known that those patients are at an increased risk for CVST (2,3). To explore the clinical characteristics and prognosis of patients who presented as PTC with CVST and JAK2 V617F, we recently reported a case series of 6 patients (4). In our series, the hematological laboratory tests resulted in high hemoglobin and hematocrit, leukocytosis, and thrombocytosis higher than 500,000 in half of the patients at diagnosis. In the case report of Kisilevsky et al, the platelet count is not mentioned, which left us wondering about the laboratory results that could shed light on the etiology. Moreover, we wonder what was the treatment and the visual outcome of that patient because in our series, 5 of 6 patients needed ventriculoperitoneal shunt insertion and 2 ended with optic atrophy and low vision. We join Kisilevsky et al in concluding that any patient with PTC and CVST from unknown reason needs screening test for JAK2V617F mutation, especially in cases of sagittal sinus or cortical sinus involvement or thrombocytosis. Ofira Zloto, MD Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Neuro-Ophthalmology Unit, Sheba Medical Center, Tel Hashomer, Israel Lubetsky Aharon, MD, MSc Thrombosis & Hemostasis Unit, Sheba Medical Center, Tel Hashomer, Israel Papilledema and Extensive Dural Sinus Thrombosis Due to JAK2 Mutation: Response W e thank Dr. Zloto Ofira et al (1) for their thoughtful response to our article. We reported a case of a 64year-old man with asymptomatic papilledema due to extensive dural venous sinus thrombosis (DVST) secondary to Janus kinase 2 (JAK2) mutation and polycythemia rubra vera (2). Although DVST due to JAK2 mutation has been previously reported, we wanted to highlight for the readers of Journal of Neuroophthalmology the importance of testing all patients e452 Anat Kesler, MD Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Peter A. Quiros, MD Stein Eye Institute, University of California, Los Angeles, California Ruth Huna-Baron, MD Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Neuro-Ophthalmology Unit, Sheba Medical Center, Tel Hashomer, Israel The authors report no conflicts of interest. REFERENCES 1. Kisilevsky E, Yu E, Margolin E. Papilledema and extensive dural sinus thrombosis due to JAK2 mutation. J Neuroophthalmol. 2020. doi:10.1097/WNO.0000000000001096 (epub ahead of print). 2. Cheung B, Radia D, Pantelidis P, Yadegarfar G, Harrison C. The presence of the JAK2 V617F mutation is associated with a higher haemoglobin and increased risk of thrombosis in essential thrombocythaemia. Br J Haematol. 2006;132:244–245. 3. Elliott MA, Tefferi A. Thrombosis and haemorrhage in polycythaemia vera and essential thrombocythaemia. Br J Haematol. 2005;128:275–290. 4. Zloto O, Lubetsky A, Ben-Bassat Mizrachi I, Kesler A, Quiros PA, Huna-Baron R. Prognostic value of JAK2V617F mutation in pseudotumor cerebri associated with cerebral venous sinus thrombosis. Acta Neurol Scand. 2019;139:166–171. with DVST for this mutation. Our patient was also unusual in several respects. As Dr. Zloto Ofira et al (3) reported, patients with hypercoagulable complications of JAK2 mutations often present earlier in life. Our patient was 64 years old at the time of presentation with no history of thrombotic events. In our article we also wanted to highlight the fact that a noncontrast MRI might be completely normal even in the presence of very extensive DVST thus the need for dedicated venography study in all patients with papilledema. In our patient, a complete blood count did not demonstrate any abnormalities: his hemoglobin was 179 g/L, leukocytes 11 · 109/L, platelets 292 · 109/L, and hematocrit 0.53 L/L. The patient that we reported presented with extensive DVST and dural sinus arteriovenous fistula, which arose Letters to the Editor: J Neuro-Ophthalmol 2022; 42: e452-454 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor as a result of presumably long-standing thrombosis. This necessitated urgent embolization. After embolization, anticoagulation therapy continued, and he also underwent serial phlebotomies to maintain a hematocrit below 45%. Hydroxyurea was offered to the patient, but he declined it due to the potential side effects. His papilledema has completely resolved and did not require any further interventions after embolization of the brain dural arteriovenous fistula that arouse at the site of DVST and treatment of the thrombosis with anticoagulation. He maintained excellent central visual acuity and normal visual fields at his last follow-up 1 year after the initial presentation. Eli Kisilevsky, MD Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada Eugene Yu, MD Department of Medical Imaging, University of Toronto, Toronto, Canada Postcataract Surgery Anterior Ischemic Optic Neuropathy W e read with great interest the excellent pointcounterpoint discussion between Drs. McCulley and Miller regarding the risk of anterior ischemic optic neuropathy (AION) after cataract surgery or postcataract surgery (pcs) AION (1). Both have contributed to the literature on this interesting and important topic that is relevant not only to neuro-ophthalmologists but also any ophthalmologist performing cataract surgery. It is probably because of the timing between the submission of the manuscript to when it was published that our recent population-based study on the incidence rate of pcsAION was not mentioned (2). We found that the incidence of AION was increased in the first year after cataract surgery, but not in the early postoperative period. The particulars were that the annual incidence rate of pcsAION within 2 months of surgery (8.6 per 100,000) was not significantly greater than the annual incidence rate of spontaneous (s) AION (6.9 per 100,000; P = 0.78) for the same 2month period. However, the annual incidence rate of pcsAION within 1 year of surgery (38.9 per 100,000) was significantly higher than the incidence rate of sAION (6.5 per 100,000; P , 0.001). A major difference between our study and the studies by Drs. McCulley (3) and Miller (4) is that we used the Rochester Epidemiology Project to identify a population-based cohort of pcsAION patients Letters to the Editor: J Neuro-Ophthalmol 2022; 42: e452-454 Edward Margolin, MD Department of Medicine, Division of Neurology, University of Toronto, Toronto, Canada Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada The authors report no conflicts of interest. REFERENCES 1. Zloto Ofira LA, Ben-Bassat Mizrachi I, Kesler A, Quiros Peter A, Ruth HB. Papilledema and cerebral venous sinus thrombosis due to JAK2 mutation: comment. J Neuroophthalmol. 2021;41:xx–xx. 2. Kisilevsky E, Yu E, Margolin E. Papilledema and extensive dural sinus thrombosis due to JAK2 mutation. J Neuroophthalmol. 2021;41:xx–xx. 3. Zloto O, Lubetsky A, Ben-Bassat Mizrachi I, Kesler A, Quiros PA, Huna-Baron R. Prognostic value of JAK2V617F mutation in pseudotumor cerebri associated with cerebral venous sinus thrombosis. Acta Neurol Scand. 2019;139:166–171. from Olmsted County, MN, which were matched to the rate of sAION from the same county over a 17-year period. By contrast, both Dr. McCulley's study from 2002 and Dr. Miller's study from 2017 identified pcsAION from a database from the Bascom Palmer Eye Institute and the Wilmer Eye Institute, respectively, and then used the incidence rate of sAION from Olmsted County, MN, published in 1997 for comparison (5). Because we compared pcsAION with sAION in the same populationbased cohort, during the same time period we believe our results are important to highlight because our study may be the closest to the true incidence of pcsAION. M. Tariq Bhatti, MD Departments of Ophthalmology and Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota Sasha A. Mansukhani, MBBS Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota John J. Chen, MD, PhD Departments of Ophthalmology and Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota The authors report no conflicts of interest. e453 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.