Arnold Andrew W, Eller Andrew M, Smith Kyle A, Grendahl Robin L, Winkle R Kevin, Arnold Robert W
Pacific Northwest University College of Osteopathic Medicine, Yakima, WA, USA.
University of Arkansas Medical School, Little Rock, AR, USA.
Clin Ophthalmol. 2020 Feb 20;14:491-499. doi: 10.2147/OPTH.S242548. eCollection 2020.
Optic nerve hypoplasia (ONH), one of the most common causes of pediatric blindness in developed countries, has been difficult to directly quantify. We sought to measure optic nerve size in Alaskan pediatric patients with optic nerve hypoplasia using ultra-widefield fundus imaging.
Adult and pediatric patients underwent conventional ultra widefield fundus imaging (OPTOS, Dunfermline, Scotland) with manual image processing to determine optic nerve size validated against refractive error and nystagmus and compared to optical spectral domain tomography. De-identified cases were then compared relative to visual acuity and birth prevalence.
In Alaska's only pediatric ophthalmology outreach clinic, 108 cases of ONH less than 20 years old were clinically identified with 80 having ultra-widefield analysis. Median horizontal optic nerve diameter for 135 normals was 1.70 (95% C.I. 1.49, 2.14) whereas in patients clinically diagnosed with optic nerve hypoplasia was 1.23 (95% C.I 0.38, 1.45). Visual acuity (20/y) was related to horizontal optic nerve diameter (x) by y = 187 x. Horizontal nerve diameter could be estimated from vertical nerve diameter by = 0.73 + 0.3 even in nystagmus patients. From 108 with ONH, 6 had threshold retinopathy of prematurity, 12 profound nystagmus, 32 legally blind, 6 with septo-optic dysplasia, and 5 with fetal alcohol syndrome. ONH is very prevalent in Alaska occurring at least 8-10 per 10,000 births.
Compared to vertical diameter, horizontal diameter was more distinctive of optic nerve hypoplasia and more perturbed by nystagmus. Both were independent of refractive error. When hand-held, spectral domain OCT is not convenient, ultra-widefield fundus analysis is recommended for direct estimation of optic nerve size in children and adults. Optic nerve hypoplasia is prevalent in Alaskan children.
视神经发育不全（ONH）是发达国家儿童失明的最常见原因之一，一直难以直接量化。我们试图使用超广角眼底成像技术测量阿拉斯加患有视神经发育不全的儿科患者的视神经大小。
成年和儿科患者接受传统的超广角眼底成像（OPTOS，邓弗姆林，苏格兰），并进行手动图像处理以确定视神经大小，该大小经屈光不正和眼球震颤验证，并与光学相干断层扫描进行比较。然后将去识别的病例与视力和出生患病率进行比较。
在阿拉斯加唯一的儿科眼科外展诊所，临床确诊了108例年龄小于20岁的视神经发育不全病例，其中80例进行了超广角分析。135名正常人的视神经水平直径中位数为1.70（95%置信区间1.49，2.14），而临床诊断为视神经发育不全的患者为1.23（95%置信区间0.38，1.45）。视力（20/y）与视神经水平直径（x）的关系为y = 187x。即使在眼球震颤患者中，视神经水平直径也可根据垂直直径通过 = 0.73 + 0.3进行估计。在108例视神经发育不全患者中，6例有阈值早产儿视网膜病变，12例有严重眼球震颤，32例法定失明，6例有视隔发育不良，5例有胎儿酒精综合征。视神经发育不全在阿拉斯加非常普遍，每10000例出生中至少发生8 - 10例。
与垂直直径相比，水平直径对视神经发育不全更具特异性，且受眼球震颤的影响更大。两者均与屈光不正无关。当手持光学相干断层扫描不方便时，建议使用超广角眼底分析直接估计儿童和成人的视神经大小。视神经发育不全在阿拉斯加儿童中很普遍。
