Functional Visual Loss

Abstract

Managing patients with functional vision loss (FVL) superimposed on organic disease is extremely challenging and frustrating for physicians who care for these patients. For this reason, we commend Ney et al1Ney J.J. Volpe N.J. Liu G.T. et al.Functional visual loss in idiopathic intracranial hypertension.Ophthalmology. 2009; 116: 1808-1813Abstract Full Text Full Text PDF PubMed Scopus (47) Google Scholar for reviewing the incidence of FVL in their patients with idiopathic intracranial hypertension (IIH). In their retrospective report, 17 of 281 IIH patients manifested FVL (6%). Nine of those 17 patients underwent a surgical procedure related to IIH at some point in their management. We recently reviewed all IIH patients seen at our institution between 1990 and 2003.2Digre K.B. Nakamoto B.K. Warner J.E. et al.A comparison of idiopathic intracranial hypertension with and without papilledema.Headache. 2009; 49: 185-193Crossref PubMed Scopus (145) Google Scholar Among 353 patients with IIH, we described in detail 20 patients who did not have papilledema at any point in their clinical course (“Idiopathic intracranial hypertension without papilledema”). Out of these 20 patients, 8 patients (20%) manifested FVL at both the initial and final visits. In their review, Ney et al state, “Thirteen of 17 patients had optic nerve-visual field mismatch, with healthy discs, that is, no edema or pallor in the setting of severe visual field loss.” May we conclude that these patients had IIH without papilledema? At least 20% of patients diagnosed with IIH also have migraine and 68% have other types of headache not necessarily related to their increased intracranial pressure.3Friedman D.I. Rausch E.A. Headache diagnoses in patients with treated idiopathic intracranial hypertension.Neurology. 2002; 58: 1551-1553Crossref PubMed Scopus (118) Google Scholar Managing headache in IIH is crucial and frequently treating both migraine and increased pressure improves outcome.3Friedman D.I. Rausch E.A. Headache diagnoses in patients with treated idiopathic intracranial hypertension.Neurology. 2002; 58: 1551-1553Crossref PubMed Scopus (118) Google Scholar, 4Wang S.J. Silberstein S.D. Patterson S. Young W.B. Idiopathic intracranial hypertension without papilledema: a case-control study in a headache center.Neurology. 1998; 51: 245-249Crossref PubMed Scopus (140) Google Scholar Did any of the subjects reported by Ney et al have migraine or headache in addition to IIH? Did these patients receive any treatment specifically for migraine or other headache syndromes not related to increased intracranial pressure? None of our 8 patients with FVL and IIH had papilledema, and none of them underwent optic nerve sheath fenestration. However, 4 patients underwent at least 1 lumbar or ventricular shunt procedure due to headaches that were refractory to medical management. Ney et al stated that of the 9 patients with FVL undergoing surgery, 5 underwent optic nerve sheath fenestration at their institutions. Four patients had undergone surgical interventions before presentation at the authors' institutions, but the nature of the surgical intervention was not stated. How many of these 4 patients underwent shunting procedures as opposed to nerve sheath procedures? In our experience, IIH patients can almost always be managed medically, and surgical intervention is only rarely required. It is therefore disconcerting that such a high proportion of patients with IIH and FVL find themselves in the operating room. Unfortunately, as stated by Ney et al, aggressive management is indicated in patients with definite organic disease and declining visual function, even if some portion of that decline is deemed to be functional. Functional Visual Loss in Idiopathic Intracranial HypertensionOphthalmologyVol. 116Issue 9PreviewTo identify and describe patients with idiopathic intracranial hypertension (IIH) with concurrent functional visual loss (FVL). Full-Text PDF Author replyOphthalmologyVol. 117Issue 6PreviewWe want to thank Dr. Katz et al1 for their insightful comments and questions regarding our paper “Functional Visual Loss in Idiopathic Intracranial Hypertension” and appreciate the opportunity to further elaborate on the points raised. Full-Text PDF