対象と方法：30歳以上80歳未満のBS患者で，2019年7月～10月の間に初めてBTX-A注射を受ける患者（初回群）と5回以上継続してBTX-A注射を受けている患者（継続群）を対象とした．エムラ®クリームは注射部位に1か所2 mgずつ塗布し，食品用ラップフィルムで30分間覆い，拭き取ってからすぐにBTX-A注射を行った．痛みの評価にはvisual analog scale（VAS）を用いた．研究1では，初回群に対し患者にはどちらかわからないように右眼にエムラ®クリーム，左眼にヒルドイド®ソフト軟膏を塗布し，32G針を用いて片眼6か所ずつBTX-Aを注射し痛みを評価した．研究2では，継続群に両眼瞼にエムラ®クリームを塗布し，過去の痛みと今回の痛みを比較した．検定にはpaired-t-testを用いた．
Purpose: To describe the prevalence and clinical characteristics of optic neuritis or neuropathy observed in the Ophthalmology Department of Gunma University Hospital.
Methods: In this retrospective study, consecutive patients with suspected optic nerve disorders seen at Gunma University Hospital from January 2016 to March 2019 were reviewed. The inclusion criteria were:（1）unilateral or bilateral acute visual disturbance or visual field disturbance;（2）positive relative afferent pupillary defect in unilateral cases or abnormalities in the optic disc. However, if anti-aquaporin 4（AQP4）or anti-myelin oligodendrocyte glycoprotein（MOG）antibodies or mitochondrial mutations were detected and both eyes revealed visual impairment, then both eyes were included; and（3）in bilateral cases, all patients required disc abnormalities in both eyes and magnetic resonance imaging（MRI）showing high-intensity in both optic nerves,（4）with no other retinal diseases. Then, the origins of optic neuritis or neuropathy were defined in all cases. All clinical characteristics were analyzed.
Results: A total of 112 eyes of 93 patients matched the criteria. Seventy-four patients showed unilateral acute visual impairment, and 59 eyes showed relative afferent pupillary defect and/or disc abnormality in 48 eyes. High-intensity MRI in the affected optic nerve was detected in 51 patients. Conversely, 38 eyes of 19 patients had bilateral acute visual loss, and a disc abnormality was detected in 20 eyes. MRI was abnormal in 25 optic nerves. Overall, major causes of optic neuritis or neuropathy were:（1）idiopathic optic neuritis（33 eyes of 32 cases, mean age ± standard deviation ［years］: 49.8±16.4）；（2）ischemic optic neuropathy（14 eyes of 14 cases, 71.4±11.4）；（3）anti-AQP4 antibody-positive optic neuritis（12 eyes of eight cases, 53.2±14.0）；（4）anti-MOG antibody-positive optic neuritis（five eyes of three cases, 10±10.6）；（5）optic neuropathy due to compression by an orbital tumor（five eyes of five cases, 65.0±18.1）；（6）Leber hereditary optic neuropathy（10 eyes of five cases, 51.8±12.2）；（7）traumatic optic neuropathy（three eyes of three cases, 29.8±15.4）；（8）rhinogenic optic neuropathy（three eyes of three cases, 61.0±12.0）； and（9）optic neuropathy due to orbital apex syndrome（three eyes of three cases, 71.0±2.9）. However, a definitive cause of optic nerve disorder could not be determined in 22 eyes of 16 cases.
Conclusions: The most common cause of optic nerve disorder in the patients examined in our department was idiopathic optic neuritis. Furthermore, ischemic optic neuropathy was the major cause in older patients.