| OCR Text |
Show Letters to the Editor Temporal Arteritis With Arteritic Anterior Ischemic Optic Neuropathy is Bilateral Until Proven Otherwise: Response neuropathy should raise the specter of bilateral optic nerve involvement and lead to consideration of GCA. Neil R. Miller, MD Tin Yan Alvin Liu, MD Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland W e thank Singh et al (1) for their remarks regarding our recent case report (2). We agree with them that: 1) timely diagnosis and treatment of giant cell arteritis (GCA) is crucial, 2) pallid swelling of the optic disc is evidence of optic nerve infarction rather than simply ischemia, 3) detection of bilateral optic nerve disease is due to GCA (or at least something more than straightforward nonarteritic anterior ischemic optic neuropathy) until proven otherwise, and, as in both their patient and ours, 4) bilateral involvement in patients with GCA may be extremely asymmetric clinically, at least from the standpoint of visual function. In such cases, the presence of a "small" or "2/4" relative afferent pupillary defect in a patient with what seems to be a severe unilateral ischemic optic Food and Drug Administration Adverse Event Reports of Retinal Vascular Occlusions Associated With Phosphodiesterase Type 5 Inhibitor Use W hile one of us (H.D.P.) recently published a review article explaining the relationship of phosphodiesterase Type 5 inhibitors (PDE5i) and nonarteritic anterior ischemic optic neuropathy (NAION) (1), this class of drugs has other ocular side effects. Most commonly, transient blue discoloration and increased brightness have been reported, which are thought to be mediated by the activity of PDE5i on PDE6, a phosphodiesterase isoenzyme localized in the retina. In addition to NAION, there are reports of retinal artery occlusions (RAO) and retinal vein occlusions (RVO) in patients taking PDE5i medications. At least 8 The authors report no conflicts of interest. REFERENCES 1. Singh N, Adarsh G, Tan J, Ewe JYP, Francis IC. Temporal arteritis with arteritic anterior ischemic optic neuropathy is bilateral until proven otherwise. J Neuroophthalmol. 2016;36:483. 2. Liu TYA, Miller NR. Giant cell arteritis presenting as unilateral anterior ischemic optic neuropathy associated with bilateral optic nerve sheath enhancement on magnetic resonance imaging. J Neuroophthalmol. 2015;35:360-363. case reports of retinal vascular occlusions associated with PDE5i have been published in the peer-reviewed literature (2-9), but the prevalence of retinal vascular occlusions is unknown. We surveyed all adverse effects associated with sildenafil (Viagra, Pfizer, Inc., New York, NY), vardenafil (Levitra, Bayer HealthCare Pharmaceuticals, Inc., Whippany, NJ), tadalafil (Cialis, Eli Lilly and Company, Indianapolis, IN), and avanafil (Stendra, Vivus, Inc., Mountain View, CA) recorded in the Food and Drug Administration (FDA) Adverse Event Reporting System from their initial FDA approval until the end of 2014 (via the Freedom of Information Act). We included all cases of RAO and RVO and excluded those in which the diagnosis was confounded by other concurrent ocular adverse events. For example, a case with a diagnosis of optic atrophy, optic nerve pallor, papilledema, optic neuropathy, ischemic optic neuropathy, or optic neuritis, in conjunction with a RAO or TABLE 1. Retinal vascular occlusions associated with PDE5i use that were reported to the FDA adverse event reporting system as of 2014 Approval by FDA Total no. adverse event reports to FDA RVOs RVOs with risk factors RAOs RAOs with risk factors Sildenafil (Viagra) Tadalafil (Cialis) Vardenafil (Levitra) Avanafil (Stendra) All PDE5i March 1998 31,901 November 2003 7,550 August 2003 5,569 April 2012 123 45,143 82 32 24 12 24 10 10 4 7 3 4 2 0 0 0 0 113 45 (39.8) 38 18 (47.4) Percentages in parentheses represent the proportion of cases of RAO or RVO with known risk factors. Patients with risk factors were identified as those who were concurrently taking a medication for the treatment of hypertension, diabetes, hyperlipidemia, or thrombosis. FDA, Food and Drug Administration; PDE5i, phosphodiesterase type 5 inhibitors; RAO, retinal artery occlusion; RVO, retinal vein occlusion. 480 Letters to the Editor: J Neuro-Ophthalmol 2016; 36: 479-481 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
