Idiopathic Intracranial Hypertension Without Papilledema With Improvement in Visual Field Defect Following Optic Nerve Sheath Fenestration: Response

Letters to the Editor Idiopathic Intracranial Hypertension Without Papilledema With Improvement in Visual Field Defect Following Optic Nerve Sheath Fenestration: Comment I Downloaded from http://journals.lww.com/jneuro-ophthalmology by BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3i3D0OdRyi7TvSFl4Cf3VC4/OAVpDDa8KKGKV0Ymy+78= on 05/04/2022 read with interest the recent article in JNO by ScofieldKaplan et al (1). Although I appreciate the difficulties authors faced in taking care of this patient, I am struck by the lack of objective evidence of visual dysfunction in this case where, literally, every intervention possible has been used (optic nerve sheath fenestration, dural sinus stenting, and now the patient is waiting for a CSF diversion procedure). Authors acknowledge the high prevalence of functional visual field loss in patients with idiopathic intracranial hypertention (IIH), and in fact, the visual fields in this patient do look nonphysiologic exhibiting very symmetric concentric constriction. Authors state that “. . . confrontational visual fields did not suggest a nonphysiologic defect” but that is not a confirmation that these fields represented organic pathology. Although authors postulate that the optic nerve swelling involved retrobulbar compartment of both optic nerves only and did not involve the optic nerve head, to my knowledge, none of the patients who were previously reported to have IIH without papilledema had central or peripheral visual loss (2,3). We also know that patients with severe IIH who have decreased central vision and severe visual field loss at presentation (which by itself is uncommon in IIH), such as the patient described in this article, will almost invariably develop varying degrees of optic nerve pallor and thinning of ganglion cell layer of the macular complex (not reported here) after the resolution of papilledema. If ganglion cell analysis of the macular complex was performed and was normal, the objective causes of optic nerve dysfunction here can be ruled out as even if increased intracranial pressure involved only the retrobulbar component of the optic nerves, it would have caused obvious loss of the ganglion cells in the macular complex, especially with the Idiopathic Intracranial Hypertension Without Papilledema With Improvement in Visual Field Defect Following Optic Nerve Sheath Fenestration: Response W e read with interest the letter from Dr. Margolin concerning our article “Idiopathic intracranial hypertension without papilledema with improvement in visual field following optic nerve sheath fenestration” (1). In reply, we wish to focus on the main point stressed in Letters to the Editor: J Neuro-Ophthalmol 2021; 41: 135-140 degree of the visual compromise this patient was reporting on subjective testing (central acuities and peripheral visual fields). On another note, measurements of opening pressure on lumbar puncture (LP) are prone to error especially when LP is not performed in lateral decubitus position as was the case here. I believe it is important to comment on this case because the obvious take home message otherwise is that any patient with severe headaches, despite the absence of papilledema is at risk of visual loss and requires further investigations and treatment, which I do not believe is the case. Although it is possible that this patient had intracranial hypertension (they did have indirect imaging sings of increased intracranial pressure and had increased opening pressure on several LPs), there was no objective evidence of visual dysfunction such as optic nerve head pallor, presence of relative afferent pupillary defect or thinning of retinal nerve fiber layer, and/or ganglion cell layer on ocular coherence tomography. Thus, it is very difficult to believe that the subjective findings here (decreased acuities and constricted visual fields) were real. Edward Margolin, MD Department of Ophthalmology and Vision Sciences and Department of Medicine, University of Toronto, Toronto, Canada The author reports no conflicts of interest. REFERENCES 1. Scofield-Kaplan SM, Patel K, Jones FR Jr, Hogan RN. Idiopathic intracranial hypertension without papilledema with improvement in visual field defect following optic nerve sheath fenestration. J Neuroophthalmol. 2021;41:e31–e33. 2. Hoffmann J, Mollan SP, Paemeleire K, Lampl C, Jensen RH, Sinclair AJ. European headache federation guideline on idiopathic intracranial hypertension. J Headache Pain. 2018;19:93. 3. Sengupta S, Eckstein C, Collins T. The dilemma of diagnosing idiopathic intracranial hypertension without papilledema in patients with chronic migraine. JAMA Neurol. 2019;76:1001– 1002. his letter, which is the lack of objective evidence of visual dysfunction. In the previous publications regarding idiopathic intracranial hypertension without papilledema (IIHWOP), the overwhelming majority have normal visual fields with few having nasal defects or nonphysiologic visual fields (2,3). In a previous study, a nonphysiologic visual field was reported if on tangent screen testing, the 3-m visual field was inside the 1-m visual field (2). Although we do not have tangent screen results for our patient, we performed confrontation visual fields at numerous distances, which did not show similar or worse constriction when confrontation 135 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Letters to the Editor visual fields were performed at further distances (i.e., there was appropriate widening of the visual field). In our practice, idiopathic intracranial hypertension oftentimes presents similarly to this patient with decreased vision, constricted visual fields, and symptoms of increased intracranial pressure (headaches, tinnitus, whooshing sensation, and transient visual obscurations). The only difference between the typical patients we see and the patient we reported was the lack of optic disc edema in either eye. The objective features in this case that support the presence of elevated intracranial pressure are the initial lack of spontaneous venous pulsations (SVPs) (with presence of SVP at her most recent follow-up after fenestration), dilation of both nerve sheaths with globe flattening on one side on the MRI, and the significant enlargement of the retrobulbar nerve sheath with a significant fluid flow or “gush” during the optic nerve sheath fenestration (ONSF). The fluid flow during ONSF was of similar caliber to patients who underwent ONSF with grade IV disc edema. We are still unclear why anatomically this fluid was not transmitted to the nerve head itself, but the presence of this fluid can lead to compression-induced ischemia of the retinal ganglion cells (4). Although the presence of optic nerve pallor or a decline in retinal nerve fiber layer (RNFL) thickness would lend further objective data, it was impossible to know what her true RNFL baseline thickness was before the onset of her headaches and visual loss. Our evaluation was approximately 2 weeks after her initial visit to the emergency department and was a few days after she had a significant loss of vision and field of vision. Furthermore, the time from our initial RNFL imaging to surgical intervention was short and may have led to relative preservation of her RNFL without further loss. Our patient recently underwent a neurosurgical shunting procedure with complete resolution of her chronic headaches. We believe a presentation of severe vision and visual field loss in IIHWOP is not common or typical but should be considered if the remainder of the examination and workup is suggestive. Scleral Lenses Versus Surgery for Ptosis in Progressive External Ophthalmoplegia Plus Respectively Kearns–Sayre Syndrome chondrial DNA (mtDNA) deletions (2), they are phenotypically distinct entities. KSS is diagnosed in the presence of all 3 core features (onset before age 20, ophthalmoplegia, and pigmentary retinopathy) and at least one of the following features: cerebrospinal fluid protein .100 mg/dL, cardiac conduction defects, or cerebellar dysfunction (3). CPEO-plus is defined as ophthalmoplegia and additional features, which do not meet the diagnostic criteria for KSS. Thus, we disagree with the notion that CPEO-plus is the same as KSS. Distinct clinical and genetic criteria for diagnosing KSS or CPEO-plus need to be accomplished before diagnosing either condition. We should know which diagnostic criteria the index patient met. We disagree that young age and expected recurrent ptosis procedures are arguments against ptosis surgery. KSS patients have a reduced life expectancy, particularly those who develop ventricular arrhythmias or heart failure, why young age does not matter. In addition, W e read with interest the article by Cherny et al (1) about a 28-year-old woman with bilateral ptosis since 17 years due to chronic progressive external ophthalmoplegia (CPEO), respectively Kearns–Sayre syndrome (KSS). Because the patient was regarded as not being an ideal patient for ptosis correction surgery due to not tolerating ptosis crutches, diplopia with lid lifting, and young age with a significant likelihood for multiple ptosis procedures, she was treated with BostonSight scleral lenses with a beneficial effect (1). We have the following comments and concerns. It is unclear if the patient had CPEO-plus or KSS. Although both are most frequently due to single mito- 136 Stacy M. Scofield-Kaplan, MD Kishan G. Patel, MD Freddie Ray Jones, Jr, MD Robert Nick Hogan, MD, PhD Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas The authors report no conflicts of interest. REFERENCES 1. Scofield-Kaplan SM, Patel KG, Jones FR Jr, Hogan RN. Idiopathic intracranial hypertension without papilledema with improvement in visual field defect following optic nerve sheath fenestration. J Neuroophthalmo. 2021;41:e31–e33. 2. Digre KB, Nakamoto BK, Warner JE, Langeberg WJ, Baggaley SK, Katx BJ. A comparison of idiopathic intracranial hypertension with and without papilledema. Headache. 2009;49:185–193. 3. Hoffmann J, Mollan SP, Paemeleire K, Lampl C, Jensen RH, Sinclair AJ. European Headache Federation guideline on idiopathic intracranial hypertension. J Headache Pain. 2018;19:93. 4. Hayreh SS. Optic disc edema in raised intracranial pressure. V. Pathogenesis. Arch Ophthalmol. 1977;95:1553–1565. Letters to the Editor: J Neuro-Ophthalmol 2021; 41: 135-140 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.