Keratoconus is a severe eye disease affecting the cornea (the clear, dome-shaped outer surface of the eye), causing it to become thin and develop a conical bulge. The diagnosis of keratoconus requires sophisticated ophthalmic devices which are non-portable and very expensive. This makes early detection of keratoconus inaccessible to large populations in low- and middle-income countries, making it a leading cause for partial/complete blindness among such populations. We propose SmartKC, a low-cost, smartphone-based keratoconus diagnosis system comprising of a 3D-printed placido's disc attachment, an LED light strip, and an intelligent smartphone app to capture the reflection of the placido rings on the cornea. An image processing pipeline analyzes the corneal image and uses the smartphone's camera parameters, the placido rings' 3D location, the pixel location of the reflected placido rings and the setup's working distance to construct the corneal surface, via the Arc-Step method and Zernike polynomials based surface fitting. In a clinical study with 101 distinct eyes, we found that SmartKC achieves a sensitivity of 87.8% and a specificity of 80.4%. Moreover, the quantitative curvature estimates (sim-K) strongly correlate with a gold-standard medical device (Pearson correlation coefficient =0.77). Our results indicate that SmartKC has the potential to be used as a keratoconus screening tool under real-world medical settings.
翻译:Keratoconus是影响角形(眼睛的清晰、圆形外表)的严重眼病,导致其变薄并形成锥形肿胀。对角形锥体的诊断需要精密的眼科装置,这些装置是非便携式的,费用非常昂贵。这使得中低收入国家的大批人口无法早期发现角形锥体,从而成为造成此类人群中部分/完全失明的主要原因。我们建议SmartKC,一个低成本、智能手机型的角形剖面诊断系统,由3D印刷的平方形直角附件、LED光谱和智能智能智能智能手机应用程序组成,以捕捉角形环的反光镜。一个图像处理管道分析角形图,并使用智能手机摄像参数、3D环的位置、反射白斑环的像素位置,以及建立角形表层的智能卡路段距离,通过Arc-Statorial C的直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径直径。