Electrophysiology and Multimodal Imaging to the Rescue
By Rachel Patel, MD; Albert T. Vitale, MD; Donnell J. Creel, PhD; and Kathleen B. Digre, MD
A 67-year-old woman was referred to neuro-ophthalmology 因为她在过去五年里注意到的视觉障碍.
在她的周边视觉中，她说她像吊扇一样不停地移动. Sometimes she would see smoke swirling around her, lights seemed to flicker, and she had prominent floaters. 她逐渐难以适应昏暗的光线. She rarely had headaches. 她看了几位眼科医生和神经科医生，并被诊断为视觉积雪, migraine with aura, or migraine symptoms.
Testing and a New Diagnosis
检查视力正常，对视视野正常.
Her slit lamp examination showed old vitreous cells. Her neurological examination was normal. 患者双眼视野外周丧失（图1）。, 光学相干断层扫描（OCT）显示双侧椭球区出现颗粒状破裂，未波及中央窝（图2）。.
由于暗适应能力差的问题，大发娱乐获得了a full-field electroretinogram （ffERG）（图3），显示杆状体功能较差，但锥体功能正常. ffERG异常加上她的玻璃体和视网膜的发现促使她转介到大发娱乐的葡萄膜炎同事. 扩张镜检查发现双侧上黄斑和周围有细微的乳黄色斑点, most prominently nasal to the optic discs (Figure 4). 吲哚菁绿血管造影（ICG）显示视网膜中周和远周有大量低荧光斑点（图4）。.
根据她的临床表现和多模态影像, a diagnosis of birdshot chorioretinopathy was made. HLA-A29阳性进一步证实了这一诊断, 并通过正常的基本实验室检查和胸部x光检查来排除结节病和淋巴瘤等其他疾病.
Birdshot Chorioretinopathy Symptoms and Treatment
Birdshot chorioretinopathy is an uncommon chronic bilateral posterior uveitis, 以典型的米色视网膜斑点分散在“鸟瞰图”模式而命名. 而几乎所有鸟射性脉络膜视网膜病变患者均为HLA-A29阳性, 常规测试是没有结果的，因为单倍型存在于大约7%的普通人群中.
鸟射性脉络膜视网膜病变可用免疫抑制治疗. Monitoring for disease activity and initiating appropriate therapy is paramount; without treatment, 疾病进展可能是潜伏的，并导致不可逆转的视力丧失.
视觉雪是一种视野中的积极视觉现象综合征. While many such patients have had migraine, 持续存在的视觉障碍将其与偏头痛先兆区分开. 视觉雪的原因被认为是大脑中的视觉处理障碍. 它被认为是一种良性疾病，治疗通常不成功. 大多数人在得知诊断结果后，都能忽略自己的症状.
As in patients with visual snow, 鸟射性脉络膜视网膜病变患者尽管视力良好，但仍可能出现视力障碍. However, 鸟射性脉络膜视网膜病变有区别于视觉雪的特征, including older age of onset, 黑暗适应延迟（与单独的夜盲症相比）, 视野中没有持续闪烁的小点. Birdshot chorioretinopathy tends to be a slowly progressive disease that can result in visual field loss and eventual loss of central visual acuity (often due to macular edema); therefore, 鉴别鸟状脉络膜视网膜病变与更良性的视觉现象病因是至关重要的.
而飞蚊症和头痛等视觉症状很常见, 并非所有的视觉症状都可归因于偏头痛或视觉雪. 可能表明黄斑或视网膜病变的迹象包括玻璃体炎, focal visual field losses, and particularly electrophysiologic abnormalities. 具有非典型症状或表现的患者可能受益于多模态成像方法来确定潜在的病因.
About the Authors
Dr. 迪格雷擅长神经眼科学和评估和治疗复杂的视觉疾病, which can be due to the optic nerve or brain disease.
Dr. Vitale是莫兰医院葡萄膜炎科的主任，也是西部山区为数不多的专门诊断和治疗葡萄膜炎以及其他眼部感染和炎症性疾病的眼科医生之一.
Dr. Creel directs electrophysiology at the Moran Eye Center.
Dr. 帕特尔是莫兰眼科中心第二年的住院医生.