Case of Bilateral Sequential Nonarteritic Ischemic Optic Neuropathy After Rechallenge With Sildenafil

Letters to the Editor search; it only became available after we had finalized our reference list. Our report of 2 patients, and the larger case series by Gates and McNeil demonstrates the value of a temporary lumbar drain in the initial management of patients with IIH who are not responding to medical therapy. These patients still need to be followed very closely after the drain is placed and removed because recurrences can occur. Mays A. El-Dairi, MD Case of Bilateral Sequential Nonarteritic Ischemic Optic Neuropathy After Rechallenge With Sildenafil A ssociation or causation between nonarteritic anterior ischemic optic neuropathy (NAION) and use of phosphodiesterase-5 (PDE-5) selective inhibitors have long been debated. A recent case-control database study failed to find such an association (1). In this journal, a Point- Counterpoint article by Lee and Vaphiades (2) outlined the difficulties of associating these 2 phenomena, and raised a question of the rechallenge effect. Only 3 such cases have been reported in the literature (2-5). We contribute one additional case of a rechallenge with sildenafil, which resulted in bilateral sequential episodes of NAION. A 66-year-old man awoke with a superior visual field defect in his left eye. He had a history of sildenafil use for approximately 7 years before presentation. The night before developing visual symptoms, he took a double dose of sildenafil. His risk factors for NAION included hypertension and hypercholesterolemia. His optic nerves had a cupto-disc ratio of 0.5 bilaterally. On examination, visual acuity was 20/20, right eye and 20/25 left eye. A left relative afferent pupillary defect was measured at 1.2 log units. The rest of his ocular examination was normal, with the exception of inferior segmental left optic disc edema and a corresponding superior visual field defect on visual field testing. He was diagnosed with NAION and asked to stop the use of sildenafil. He underwent laboratory work-up for giant cell arteritis, 24-hour blood pressure monitoring, carotid ultrasound testing and an MRI of the orbits, all of which were negative. His vision progressively deteriorated, and then stabilized at 1/200. One year later, the patient developed a superior altitudinal defect in the right eye after using sildenafil 2 days in a row. Visual acuity was 1/200, right eye and 20/30, left eye. He had a 0.9 log unit right relative afferent pupillary defect. There was segmental inferior right optic disc edema, with a central and superior altitudinal visual field defect on visual field testing. Letters to the Editor: J Neuro-Ophthalmol 2018; 38: 122-133 Department of Ophthalmology, Duke University, Durham, North Carolina M. Tariq Bhatti, MD Departments of Ophthalmology and Neurology, Duke University, Durham, North Carolina The authors report no conflicts of interest. Our case of sildenafil use and bilateral sequential NAION illustrates a clear rechallenge effect of this PDE-5 inhibitor. In their Letter to the Editor, Kruger and Pomeranz (6) raise a plausible question of whether it is the use of PDE inhibitors or simply their association with sexual activities after ingestion of PDE inhibitors that cause compromise of the blood supply to the optic nerve head. Despite the controversy, we will continue to counsel patients to avoid the use of PDE inhibitors if they were temporally associated with an episode of NAION. Anastasia Neufeld, MD Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah Judith Warner, MD Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah Department of Neurology, University of Utah, Salt Lake City, Utah Supported in part by an Unrestricted Grant from Research to Prevent Blindness, Inc, New York, NY, to the Department of Ophthalmology & Visual Sciences, University of Utah. The authors report no conflicts of interest. REFERENCES 1. Nathoo NA, Etminan M, Mikelberg FS. Association between phosphodiesterase-5 inhibitors and nonarteritic anterior ischemic optic neuropathy. J Neuroophalthalmol. 2015;35:12-15. 2. Lee MS, Vaphiades M. Are erectile dysfunction medications causally related to nonarteritic anterior ischemic optic neuropathy? J Neuroophthalmol. 2016;36:202-207. 3. Pepin S, Pitha-Rowe I. Stepwise decline in visual field after serial sildenafil use. J Neuroophthalmol. 2007;28:76-77. 123 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor 4. Bollinger K, Lee MS. Recurrent visual field defect and ischemic optic neuropathy associated with tadafil rechallenge. Arch Ophthalmol. 2005;123:400-401. 5. Pomeranz HD, Bhavsar AR. Nonarteritic ischemic optic neuropathy developing soon after use of sildenafil (Viagra): a report of seven new cases. J Neuroophthalmol. 2005;25:9-13. 6. Kruger JM, Pomeranz HD. Nonarteritic anterior ischemic optic neuropathy and erectile dysfunction drugs: is there an elephant in the bedroom? J Neuroophthalmol. 2017;37:104-105. Case of Bilateral Sequential Nonarteritic Ishemic Optic Neuropathy After Rechallenge With Sildenafil: Comment NAION in which associated sexual activity was specifically denied. We simply suggest that sexual activity itself may be another independent risk factor for NAION. Howard D. Pomeranz, MD, PhD Department of Ophthalmology, Northwell Health, Great Neck, New York I n their letter to the editor, Neufeld and Warner (1) present a fourth case of PDE-5 inhibitor-associated NAION with rechallenge effect. Although we appreciate their reference to our publication, we find it puzzling that they do not address the very question that we advocated exploring in such cases. What was the sexual history of their patient? Sexual intercourse itself has a plausible mechanism to provoke NAION through postcoital hypotension. The argument by Neufeld and Warner that sildenafil was the cause of the NAION would be better substantiated if they confirmed that there was no associated sexual activity. Regardless, their case does not conflict with our position. In our letter, we acknowledged evidence to implicate the drug itself including several reports of PDE-5 inhibitor-associated Macular Ganglion Cell Complex Reduction Preceding Visual Field Loss in a Patient With Chiasmal Compression With a 21Month Follow-Up T ieger et al (1) reported a series of 23 patients with chiasmal compression evaluated with optical coherence tomography (OCT) and standard automated perimetry (SAP) before and after surgical treatment. Because some of their patients showed complete visual field (VF) recovery despite persistent retinal ganglion cell (RGC) layer thinning on OCT, the authors suggested that RGC loss may precede VF loss, at least when assessed with standard 24-2 or 30-2 threshold strategies. Two invited commentaries pointed out that this is still an unsettled issue regarding compressive disorders of the anterior visual pathway (2,3). I had the opportunity to assess a patient with a pituitary tumor compressing the chiasm, followed for 21 months with OCT, SAP, and manual Goldmann perimetry (GP). My findings strongly support those of Tieger et al. A 56-year-old woman was seen for a follow-up examination because of a nonsecreting pituitary adenoma mildly compressing the optic chiasm. The adenoma was discovered 8 years previously when MRI was obtained for her menstrual 124 Joshua Kruger, MD, PhD Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel The authors report no conflicts of interest. REFERENCE 1. Neufeld A, Warner J. Case of bilateral sequential nonarteritic ischemic optic neuropathy after rechallenge with sildenafil. J Neuroophthalmol. 2018;38:123-124. irregularities. At that time, the patient had no visual complaints, visual acuity (VA) was 20/20 bilaterally, and the remainder of the ophthalmic examination, including ophthalmoscopy, was normal. SAP (24-2 Swedish Interactive Threshold Algorithm standard test on the automated perimeter) and GP using the I/4e, I/3e, I/2e, and I/1e targets (with kinetic and central static presentations) were also normal. The patient opted for conservative management with visual and neuroimaging re-evaluation every 6 months. Five years later, with the patient still asymptomatic, bilateral VF defects to the I/2e and I/I3 isopters were detected using GP. MRI showed a small hemorrhage within the pituitary tumor, but the patient declined surgery. Six months later, VF improvement was observed, attributed to slight tumor shrinkage found on MRI. She was followed at 6-month intervals, with minimal VF depression (on both perimeters) in the upper temporal quadrant of each eye. Six years after initial evaluation, the patient's acuity remained 20/20 bilaterally, VFs were stable (Fig. 1A), and OCT (3D OCT-2000; Topcon Corp, Tokyo, Japan) in each eye was performed. It showed the peripapillary retinal nerve fiber layer (RNFL) to be within normal limits, but the RGC-inner plexiform layer (IPL) in the macular area displayed few points of significant reduction in each nasal hemiretina (Fig. 1A). The GP showed a few points of Letters to the Editor: J Neuro-Ophthalmol 2018; 38: 122-133 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.