Department of Imaging Physics, Delft University of Technology, Delft, the Netherlands.
Rotterdam Ophthalmic Institute, Rotterdam Eye Hospital, Rotterdam, the Netherlands.
Transl Vis Sci Technol. 2020 Aug 21;9(2):49. doi: 10.1167/tvst.9.2.49. eCollection 2020 Aug.
To present a fully automatic method to estimate the corneal endothelium parameters from specular microscopy images and to use it to study a one-year follow-up after ultrathin Descemet stripping automated endothelial keratoplasty.
We analyzed 383 post ultrathin Descemet stripping automated endothelial keratoplasty images from 41 eyes acquired with a Topcon SP-1P specular microscope at 1, 3, 6, and 12 months after surgery. The estimated parameters were endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX). Manual segmentation was performed in all images.
Our method provided an estimate for ECD, CV, and HEX in 98.4% of the images, whereas Topcon's software had a success rate of 71.5% for ECD/CV and 30.5% for HEX. For the images with estimates, the percentage error in our method was 2.5% for ECD, 5.7% for CV, and 5.7% for HEX, whereas Topcon's software provided an error of 7.5% for ECD, 17.5% for CV, and 18.3% for HEX. Our method was significantly better than Topcon's ( < 0.0001) and was not statistically significantly different from the manual assessments ( > 0.05). At month 12, the subjects presented an average ECD = 1377 ± 483 [cells/mm], CV = 26.1 ± 5.7 [%], and HEX = 58.1 ± 7.1 [%].
The proposed method obtains reliable and accurate estimations even in challenging specular images of pathologic corneas.
CV and HEX, not currently used in the clinic owing to a lack of reliability in automatic methods, are useful biomarkers to analyze the postoperative healing process. Our accurate estimations allow now for their clinical use.
提出一种从共焦显微镜图像中自动估计角膜内皮参数的方法,并用于研究超薄型撕囊自动角膜内皮移植术后一年的随访。
我们分析了 41 只眼 383 张超薄型撕囊自动角膜内皮移植术后的共焦显微镜图像,这些图像是在术后 1、3、6 和 12 个月使用 Topcon SP-1P 共焦显微镜获得的。估计的参数是内皮细胞密度(ECD)、变异系数(CV)和六边形性(HEX)。所有图像均进行手动分割。
我们的方法在 98.4%的图像中提供了 ECD、CV 和 HEX 的估计值,而 Topcon 的软件对 ECD/CV 的成功率为 71.5%,对 HEX 的成功率为 30.5%。对于有估计值的图像,我们的方法的百分比误差为 ECD 为 2.5%,CV 为 5.7%,HEX 为 5.7%,而 Topcon 的软件提供的误差为 ECD 为 7.5%,CV 为 17.5%,HEX 为 18.3%。我们的方法明显优于 Topcon 的(<0.0001),与手动评估无统计学差异(>0.05)。在第 12 个月,患者的平均 ECD=1377±483[个/毫米],CV=26.1±5.7[%],HEX=58.1±7.1[%]。
即使在病理性角膜的有挑战性的共焦图像中,该方法也能获得可靠和准确的估计值。
CV 和 HEX 目前由于自动方法的可靠性问题尚未在临床上使用,但它们是分析术后愈合过程的有用生物标志物。我们的精确估计现在允许它们在临床上使用。