Neuro-Ophthalmic Literature Review

Neuro-Ophthalmic Literature Review David Bellows, Noel Chan, John Chen, Hui-Chen Cheng, Peter MacIntosh, Sui Wong, and Michael Vaphiades Asian or Caucasian? In Optic Neuritis it Makes a Difference KimH, Park KA,Oh SY,Min JH, KimBJ. Association of optic neuritis with neuromyelitis optica spectrum disorder and multiple sclerosis in Korea. Korean J Ophthalmol. 2019 Feb 1;33(1):82–90. There are significant differences in the expression of optic neuritis between different ethnic groups. In particular, neuromyelitis optica has been shown to be more prevalent in Asians, Indians and Blacks. It is important to recognise this distinction because early identification and intervention can improve outcomes. This retrospective study was performed on 125 eyes of 91 Korean patients presenting to the Neuroophthalmology Department at Samsung Medical Center with acute optic neuritis. These patients were eventually diagnosed with idiopathic optic neuritis, neuromyelitis optica spectrum disorder (NMOSD) or multiple sclerosis. The diagnoses of NMOSD and multiple sclerosis were based upon the Wingerchuk or McDonald criteria, respectively. These patients were followed for six months to 16 years (mean 3.7 years) and all but seven of the patients were tested for NMO-IgG. There are several interesting findings that distinguish optic neuritis in Asians from the same entity in Caucasians. These include the fact that only 63%of the patients were female, only 56% of eyes had pain and disk swelling was noted in 53% of eyes. During the follow-up period, 80%of patientswere diagnosedwith idiopathic optic neuritis, 15% were diagnosed with NMOSD and 4% were diagnosed with definite multiple sclerosis. Unlike patients in the Optic Neuritis Treatment Trial (ONTT), where 95% achieved a visual acuity of 20/40 or better, only 73% of eyes in this study achieved a similar outcome. This paper emphasises the importance of testing for NMO-IgG antibodies in all patients with acute optic neuritis, particularly in those of Asian ethnicity. Early diagnoses and intervention in these patients can significantly improve outcomes. David Bellows Endoscopic Orbital Decompression in Acute Optic Neuritis with Sinusitis? Neo, WL, Chin, DCW, Huang, XY. Rhinogenous optic neuritis with full recovery of vision – The role of endoscopic optic nerve decompression and a review of literature. Am J Otolaryngol. 2018 Nov;39(6):791–795. Paranasal sinusitis may result in different orbital complications and infrequently optic neuritis. Traditionally, themainstay of treatment is intravenous antibiotics with or without steroids. The authors present a case of acute painless optic neuritis with disc swelling in a patient with pansinusitis and nasal polyposis. Computer tomography showed opacification adjacent to the right orbital apex while magnetic resonance imaging showed extensive inflammatory changes towards the lesser wing of the sphenoid and orbital walls. There was no mucocoele or evidence of direct compression. Nevertheless, the patient received emergent right functional endoscopic sinus surgery with optic nerve decompression apart from intravenous antibiotics and steroids. Dramatic visual recovery from no light perception to 6/9 was noted 10 h postoperatively. The authors postulated that an inflammatory process can exert compression onto the optic nerve and thus surgical treatment might be beneficial in these cases upon early diagnosis. CONTACT John Chen chen.john@mayo.edu Department of Ophthalmology and Neurology, Mayo Clinic Hospital, 200 First Street SW, MN 55905, Rochester NEURO-OPHTHALMOLOGY 2019, VOL. 43, NO. 3, 208–211 https://doi.org/10.1080/01658107.2019.1610313 © 2019 Taylor & Francis Group, LLC The role of optic nerve decompression is better established in cases such as compressive optic neuropathies, thyroid associated orbitopathies or idiopathic intracranial hypertension. Its role in inflammatory/ infective optic neuritis is unknown. In the literature review, visual outcomes from this procedure in similar settings have been variable as the reported time frame of intervention was heterogeneous. As the patient also received intravenous antimicrobial agents and steroids before the surgery, it is difficult to delineate the efficacy of decompression surgery in optic neuritis associated with sinusitis based on this one case. Further studies are required to study its effectiveness and the proper time frame of surgical intervention in this scenario. Noel Chan Müller Cells are Affected in Neuromyelitis Optica You Y, Zhu L, Zhang T, Shen T, Fontes A, Yiannikas C, Parratt J, Barton J, Schulz A, Gupta V, Barnett MH. Evidence of Müller Glial dysfunction in patients with aquaporin-4 immunoglobulin G–positive neuromyelitis optica spectrum disorder. Ophthalmology. 2019 Feb 1. Article in Press. Antibodies to aquaporin-4 (AQP4) are known to be the pathologic marker for neuromyelitis optica spectrum disorder (NMOSD), which is classically associated with optic neuritis and transverse myelitis. The authors explored the functional and structural changes in the retina in patients with AQP4antibody (AQP4-IgG)-positive NMOSD by comparing full-field ERG and OCT segmentation among 22 patients with NMOSD, 131 with multiple sclerosis (MS), and 28 normal subjects. AQP4+NMOSD patients had a reduced b-wave amplitude in scotopic ERG, but not in photopic ERG. This reduction was mostly caused by a reduction of the slowPII component, which suggests this change is from Müller cell dysfunction. AQP4 +NMOSD patients also had a thinner Henle fiber outer nuclear layer and inner segment layer on OCT, which was associated with the scotopic b-wave amplitude reduction. These layers corresponded to the Müller cell distribution in the human retina areas of the retina and were shown to express AQP4 on histopathology. One limitation is the small sample size of NMOSD patients. While the histopathologic studies demonstrated that AQP4 expression was predominantly within Müller cells, postmortem studies in AQP4IgG positive NMOSD patients will be required to confirm these findings. This study suggests that Müller cells are affected in eyes with AQP4+NMOSD and therefore may play a role in the pathophysiology of AQP4 antibody pathology. Future studies will be required to confirm whether ERG and retinal imaging could be used as biomarkers to diagnose AQP4+NMOSD. John Chen Patten Electroretinogram (PERG) and Visual Evoked Potential (VEP) Values didn’t Change Significantly During 12-Months Follow-up in Patients with Chronic Leber‘S Hereditary Optic Neuropathy (LHON) ParisiV, Ziccardi L, SadunF,DeNegriAM, LaMorgia C, Barbano L, Carelli V, Barboni P. Functional changes of retinal ganglion cells and visual pathways in patients with Leber’s hereditary optic neuropathy during one year of follow-up in chronic phase. Ophthalmology. 2019 Feb 26. Article in press The authors enrolled 22 patients with amolecularly confirmed diagnosis of Leber‘s hereditary optic neuropathy (LHON) with mean disease duration of 18.8 years, and 25 age-similar controls. They aimed to study the differences of Patten Electroretinogram (PERG) and Visual Evoked Potential (VEP) between LHON and normal controls, and they also compared the longitudinal changes during 12-months follow-up in these chronic LHON patients. At baseline, LHON eyes showed a significant reduction in amplitude of PERG compared to controls. In the LHON group, the mean amplitude of PERG did not differ between baseline, 6and 12-months follow-up. Regarding VEP, LHON eyes showed significantly increased peak time and reduced amplitude compared to controls. During longitudinal follow-up, the mean peak time and amplitude of VEP did not change significantly in LHON patients. The authors suggested that electrophysiology studies should be considered when attempts for treatments are proposed in chronic LHON. Hui-Chen Cheng NEURO-OPHTHALMOLOGY 209