Automated Software Analysis of Corneal Micrographs for Peripheral Neuropathy

Abstract

PURPOSE.A relationship has been reported between the presence of peripheral neuropathy and the density and shape of corneal nerve fibers. Peripheral neuropathy is a debilitating condition that arises from many common health problems, and its presence is often confirmed with an invasive clinical test called intramuscular electromyography (EMG). In this study, the possibility of developing an alternative or adjunct test to EMG based on the appearance of nerve fibers in corneal micrographs was explored. Since corneal imaging is virtually noninvasive compared with EMG, such a test may be administered more liberally and frequently, before neuropathy symptoms occur. METHODS. A software program that automatically traces nerve fibers in corneal micrographs and generates measures based on these traces was implemented. This software was applied to a database of images collected by confocal laser scanning corneal microscopy from diabetic subjects whose levels of neuropathy were measured with EMG and from healthy subjects. RESULTS. Trends in the nerve fiber density and various measures of shape were calculated and observed, to explore the possibility of using these measures as a clinical tool for corroborating symptoms, confirming an evaluation, or evaluating risk factors for developing neuropathy. CONCLUSIONS. Preliminary statistical trends show a potential for measuring and observing neuropathy severity or for providing an objective risk measure for a patient's ensuing condition. More work is needed in the development of the measures and in their testing to prove that the measures can be made repeatable in a clinical environment. (Invest Ophthalmol Vis Sci.

Repeatability of In Vivo Corneal Confocal Microscopy to Quantify Corneal Nerve Morphology

“…Possible solutions include the adoption of internationally accepted criteria and rules to identify the different corneal nerve structures or the development of fully automated image analysis software. [30][31][32][33] Two recent studies have demonstrated high repeatability of IVCCM but focused primarily on NFL. 34,35 Hence, the aim of this study was to establish intraobserver, interobserver, and between-eye repeatability and agreement in control subjects for each of the 4 key parameters used to quantify neuropathy.…”

Automatic Evaluation of Corneal Nerve Tortuosity in Images from In Vivo Confocal Microscopy

“…Clinical parameters such as length and density of the nerves are essential in collecting objective information related to the cornea's state of health, and the usefulness of measuring nerve tortuosity was recently investigated. 2,3 An important link has been shown between nerve tortuosity and the severity of diabetic neuropathy, one of the most common and serious long-term complications of diabetes. 4,5 The subbasal nerve tortuosity coefficient decreased significantly after corneal refractive surgery, 6 and nerve fibers appeared shorter and more tortuous in the posttransplantation corneas than in normal corneas.…”

Diabetic peripheral neuropathy assessment through texture based analysis of corneal nerve images

“…The methods proposed by different research groups are based on automatic algorithms for nerve segmentation and extraction of morphology parameters. These parameters are then analyzed using statistical between groups comparison tests, for identifying differences between controls and patients groups, or using classification techniques to assign individuals to those groups [16,17,20]. This approach requires robust automatic nerve segmentation algorithms able to perform even with lower quality images.…”

“…It was also demonstrated that corneal nerve fibre loss correlates with intra-epidermal nerve fibre loss [2], with the parameter corneal nerve fibre length showing higher discriminative capacity to diagnose DPN [15]. Recent works focus on the development of accurate methods for automatic segmentation and analysis of corneal nerves on CCM images [16][17][18][19][20][21] and on the reproducibility of CCM in the evaluation of corneal nerves morphology, using manual, semi-automated and automatic methods [22][23][24]. A review on this research area was recently published [25].…”