Neuro-Ophthalmic Literature Review

Neuro-Ophthalmic Literature Review David A. Bellows, John J. Chen, Hui-Chen Cheng, Peter W. MacIntosh, Jenny A. Nij Bijvank, Michael S. Vaphiades, Konrad P. Weber, and Sui H. Wong Duane Syndrome – Proposal for a new classification system Lee YJ, Lee H-J, Kim S-J. Clinical features of duane retraction syndrome: a new classification. Korean J Ophthalmol. 2020;34(2):158–165. doi: 10.3341/ kjo.2019.0100 This retrospective study is based on the analysis of the medical records of 65 patients with Duane Retraction Syndrome (DRS) who visited the Seoul National University Children’s Hospital between 2010 and 2017. The authors have proposed a new and simplified classification system based solely on the angle of deviation in primary gaze. Patients with an exotropia greater than 3 dioptres were classified as “Exo-Duane,” those with an exotropia or esotropia measuring less than 3 dioptres were labelled “Ortho-Duane” and finally, those with an esotropia exceeding 3 dioptres were classified as “Eso-Duane.” Exo-Duane was found to be the most common presentation (53.8%) while 33.8% were Eso-Duane and 12.3% were Otho-Duane. 56.9% of the patients were male and 43.1% were female with no significant difference in sex proportion between the subclassifications. As documented in previous studies, there was a predominance of left eye involvement (70.8%) followed by the right eye (24.6%) and both eyes (4.6%). In addition to the deviation in primary position the authors report an upshoot of the affected eye in 35.4%, a downshoot in 15.4%, narrowing of the palpebral fissure in 46.2%, and globe retraction in 9.2%. 9.2% of patients also had a hypertropia, predominantly in the Exo-Duane group. The most common refractive error was hyperopia (68.9%) followed by myopia in (26.2%). Comorbidities were found in 10.8% of patients including Goldenhar syndrome, Noonan syndrome and asthma. One patient had a “central nervous system” disease which was not further defined. The authors make the point that the Huber system of classifications is somewhat incommodious for several reasons. The Huber classification is partially based on EMG patterns which are not always feasible to obtain and frequently present with atypical patterns. The Huber classification also relies on subjective and, therefore, inconsistent estimates of abduction or adduction deficits. The authors propose that this new and simplified classification is based on objective findings alone and will enable better communication between practitioners. David A. Bellows Ocular changes in astronauts from spaceflight Macias BR, Patel NB, Gibson CR, Samuels BC, Laurie SS, Otto C, Ferguson CR, Lee SM, PloutzSnyder R, Kramer LA, Mader TH. Association of long-duration spaceflight with anterior and posterior ocular structure changes in astronauts and their recovery. JAMA Ophthalmol. 2020. Advance publication online. doi: 10.1001/ jamaophthalmol.2020.0673 In this longitudinal prospective cohort study, the investigators evaluated the ocular health of 11 astronauts before, during, and after six-month missions on board the International Space Station (ISS) using optical coherence tomography (OCT) to determine the effects of Spaceflight Associated Neuro-Ocular Syndrome (SANS). The optic nerve head rim tissue and peripapillary choroidal thickness both increased during spaceflight with the majority of change occurring during CONTACT John J. Chen Chen.john@mayo.edu Mayo Clinic Department of Ophthalmology, Rochester, MN, 55905, USA NEURO-OPHTHALMOLOGY 2020, VOL. 44, NO. 4, 275–280 https://doi.org/10.1080/01658107.2020.1773173 © 2020 Taylor & Francis Group, LLC the first 90 days of spaceflight. At flight day 150, the mean change in optic nerve head rim tissue thickness and choroidal thickness were 35.7 μm (10% change) and 43 μm (18% change) respectively. These changes returned back to normal over 90 days after returning to Earth. The axial eye length and anterior chamber depth were decreased by a mean of 0.08 mm and 0.09 mm respectively upon return to Earth and these changes persisted after oneyear. These structural changes were associated with a hyperopic shift, which persisted as well. The primary limitation of the study was the small number of participants. In addition, the optical biometry for measuring axial eye length was not conducted during spaceflight. This was the first study to report the time course and recovery of ocular changes that develop in astronauts during spaceflight, which may provide insight into the mechanism of SANS. It demonstrated that the retinal and choroidal thickening is reversible upon returning to Earth, but the axial length and hyperopic shifts can be permanent. These findings are important as we prepare for longer spaceflight mission to Mars and beyond. John J. Chen Artificial intelligence can help to diagnose papilloedema Milea D, Najjar RP, Zhubo J, Ting D, Vasseneix C, Xu X, Aghsaei FM, Fonseca P, Vanikieti K, Lagreze WA, La Morgia C, Cheung CY, Hamann S, Chiquet C, Sanda N, Yang H, Mejico LJ, Rougier MB, Kho R, Thi HCT, Singhal S,Gohier P, Clermont-Vignal C, Cheng CY, Jonas JB, Yu-Wai-Man P, Fraser CL, Chen, JJ, Ambika S, Miller NR, Liu Y, Newman NJ, Wong TY, Biousse V, Bonsai Group. Artificial intelligence to detect papilloedema from ocular fundus photographs. N Engl J Med. 2020;382:1687–95. doi: 10.1056/NEJMoa1917130 The authors aimed to use artificial intelligence to discriminate papilloedema and other optic disc abnormalities from fundus photographs. They collected 15,846 ocular fundus photographs obtained with pharmacologic pupillary dilation retrospectively from multiple centres. Of these photographs, 14,341 photographs, including 9156 of normal discs, 2148 of discs with papilloedema, and 3037 of discs with other abnormalities, were used for training and validation of the deep-learning system. The remaining 1505 photographs were used for external testing. This deep-learning system had an area under the receiver-operating characteristic curve (AUC) for the detection of papilloedema of 0.96, a sensitivity of 96.4%, and a specificity of 84.7%. In addition, negative predictive values were high in this algorithm, but positive predictive values varied from different populations. A deeplearning system using fundus photographs can differentiate among optic discs with papilloedema, normal discs, and discs with nonpapilledema abnormalities. Further investigation is required to prospectively validate the use of deep-learning systems in different populations. Hui-Chen Cheng Disease progression in patients with multiple sclerosis may be monitored by retinal volumetric vessel density Jiang H, Gameiro GR, Liu Y, Lin Y, Jeffrey H, Deng Y, Gregori G, Delgado S, Wang J. Visual function and disability are associated with increased retinal volumetric vessel density in patients with multiple sclerosis. Am J Ophthalmol. 2020;213:34–45. doi: 10.1016/j.ajo.2019.12.021. The authors aimed to investigate the retinal volumetric vessel density (VVD), and its correlations with visual function and disability in patients with relapsing-remitting multiple sclerosis (RRMS). They enrolled 80 patients with RRMS, including 123 eyes without a history of optic neuritis (MSNON) and 36 eyes with a history of ON (MSON), and 99 ageand gendermatched healthy controls (HC). The VVD was calculated as the vessel density (VD) derived from optical coherence tomography angiography (OCTA) divided by the corresponding tissue volume measured using OCT. Specifically, the VVD of retinal vascular network (RVN) was VD of the RVN divided by the tissue volume from the retinal nerve fibre layer (RNFL) to outer plexiform layer (OPL) in the same circular area. VVD of superficial vascular plexus (SVP) and deep vascular plexus (DVP) were the VD of the SVP and DVP divided by these corresponding 276 D. A. BELLOWS ET AL.