Eyeworld

39 EW FEATURE June 2018 • Neuro-ophthalmology for the anterior segment surgeon the lowest rate—30%—of misinter- pretation of PE. The rates of misin- terpretation of PE as PPE were much higher for ultrasound, autofluores- cence, and all OCT protocols. All of the imaging modalities except OCT RNFL were better at detecting superficial compared with suspected buried ODD. Additionally, the study authors warned that the findings indicated that the use of isolated imaging modalities was more likely to lead to misinterpretation of PE as PPE, "which could potentially result in failure to identify a life-threatening disorder causing elevated intracrani- al pressure and papilledema." Why misinterpreted Stacy Pineles, MD, Jerome and Joan Snyder Chair in Ophthalmology, Stein Eye Institute, UCLA, Los An- geles, and one of the study authors, said the most common reason that optic nerves are misinterpreted as swollen is optic disc drusen. But sometimes congenitally anomalous nerves or optic nerves of very hyper- opic children can appear swollen. When an asymptomatic patient presents and Dr. Pineles is not sure if the optic nerve is swollen, she typ- ically starts with taking a thorough history. She pays special attention to symptoms that might occur if a patient has elevated intracranial pressure, such as headache, nausea or vomiting, diplopia, and pulsatile tinnitus. "Then I evaluate the optic nerve and look for signs of true optic nerve edema (absent spontaneous venous pulsations, blurring of the vessels as they cross the disc margin, hemorrhage, exudates)," Dr. Pineles said. Clinical signs Melinda Chang, MD, assistant professor, neuro-ophthalmology and pediatric ophthalmology, UC Davis Eye Center, Sacramento, California, and a co-author of the study, said among the clinical sign she finds most helpful to confirm accuracy in such cases is the presence of sponta- neous venous pulsations. "Typically, the absence of the blurred vessels at the disc margin is the best sign," Dr. Chang said. Among the ancillary testing Dr. Chang recommends are disc photos. "Disc photos are often useful in small children because you can carefully study every single aspect of the disc, which is hard to do in a moving child," Dr. Chang said. She also uses fluorescein angi- ography whenever possible. Ultra- sound is the last resort for her since it's only positive if the drusen are calcified. Dr. Chang noted that OCT is helpful in some cases but it also can be misinterpreted. "The role for OCT is still evolv- ing as technology improves," Dr. Chang said. EW Reference 1. Chang MY, et al. Accuracy of diagnostic im- aging modalities for classifying pediatric eyes as papilledema versus pseudopapilledema. Ophthalmology. 2017;124:1839–1848. Editors' note: Drs. Pineles and Chang have no financial interests related to their comments. Contact information Pineles: Pineles@jsei.ucla.edu Chang: mywchang@ucdavis.edu Enhanced depth imaging optical coherence tomography (EDI-OCT) characteristics of buried optic disc drusen (top) and optic disc edema (bottom). Both scans show a peripapillary hyperreflective area, which was interpreted as optic disc drusen by neuro-ophthalmologists. EDI-OCT did not distinguish between buried optic disc drusen and optic disc edema. Source (all): Melinda Chang, MD Poll size: 132 When I see a patient in whom there is a suspicion of optic neuritis, I: Manage the patient myself Refer the patient to one of my partners Refer to a neurologist Refer to a neuro-ophthalmologist For differentiating papilledema from pseudopapilledema (buried disc drusen), I perform: B-scan ultrasound MRI Fluorescein angiography OCT

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