Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Baltimore, Maryland, United States of America.
Larner College of Medicine, University of Vermont, Burlington, Vermont, United States of America.
PLoS Negl Trop Dis. 2021 Nov 8;15(11):e0009928. doi: 10.1371/journal.pntd.0009928. eCollection 2021 Nov.
As the prevalence of trachoma declines worldwide, it is becoming increasingly expensive and challenging to standardize graders in the field for surveys to document elimination. Photography of the tarsal conjunctiva and remote interpretation may help alleviate these challenges. The purpose of this study was to develop, and field test an Image Capture and Processing System (ICAPS) to acquire hands-free images of the tarsal conjunctiva for upload to a virtual reading center for remote grading.
METHODOLOGY/PRINCIPAL FINDINGS: This observational study was conducted during a district-level prevalence survey for trachomatous inflammation-follicular (TF) in Chamwino, Tanzania. The ICAPS was developed using a Samsung Galaxy S8 smartphone, a Samsung Gear VR headset, a foot pedal trigger and customized software allowing for hands-free photography. After a one-day training course, three trachoma graders used the ICAPS to collect images from 1305 children ages 1-9 years, which were expert-graded remotely for comparison with field grades. In our experience, the ICAPS was successful at scanning and assigning barcodes to images, focusing on the everted eyelid with adequate examiner hand visualization, and capturing images with sufficient detail to grade TF. The percentage of children with TF by photos and by field grade was 5%. Agreement between grading of the images compared to the field grades at the child level was kappa = 0.53 (95%CI = 0.40-0.66). There were ungradable images for at least one eye in 199 children (9.1%), with more occurring in children ages 1-3 (18.5%) than older children ages 4-9 (4.2%) (χ2 = 145.3, p<0.001).
CONCLUSIONS/SIGNIFICANCE: The prototype ICAPS device was robust, able to image 1305 children in a district level survey and transmit images from rural Tanzania to an online grading platform. More work is needed to improve the percentage of ungradable images and to better understand the causes of disagreement between field and photo grading.
随着沙眼在全球范围内的患病率下降，为了记录消除情况，对现场分级人员进行标准化变得越来越昂贵和具有挑战性。对睑结膜进行摄影和远程解读可能有助于缓解这些挑战。本研究的目的是开发并现场测试图像采集和处理系统（ICAPS），以获取睑结膜的免手持图像，并上传到虚拟阅读中心进行远程分级。
方法/主要发现：本观察性研究是在坦桑尼亚 Chamwino 区进行的沙眼性炎症滤泡（TF）流行率调查期间进行的。ICAPS 是使用三星 Galaxy S8 智能手机、三星 Gear VR 耳机、脚踏触发和定制软件开发的，该软件允许免手持摄影。经过一天的培训课程，三名沙眼分级员使用 ICAPS 从 1305 名 1-9 岁的儿童中采集图像，这些图像由专家远程分级，以便与现场分级进行比较。根据我们的经验，ICAPS 成功地对图像进行了扫描和条形码分配，将重点放在充分展示检查者手部的翻转眼睑上，并拍摄到足够详细的图像以进行 TF 分级。通过照片和现场分级，TF 儿童的比例为 5%。图像分级与儿童水平的现场分级之间的一致性为 kappa = 0.53（95%CI = 0.40-0.66）。至少有一只眼睛无法分级的图像有 199 张（9.1%），年龄在 1-3 岁的儿童中（18.5%）比年龄较大的儿童（4-9 岁）（χ2 = 145.3，p<0.001）更多。
结论/意义：原型 ICAPS 设备坚固耐用，能够对一个地区的 1305 名儿童进行成像，并将图像从坦桑尼亚农村传输到在线分级平台。需要做更多的工作来提高不可分级图像的比例，并更好地理解现场分级和照片分级之间差异的原因。
