Abstract
Purpose :
To test the ability of a new Dresden biomechanical glaucoma index (BGI) based on dynamic corneal response (DCR) parameters and corneal thickness to discriminate between healthy from normal pressure glaucoma (NPG) patients.
Methods :
Forty-two patients with NPG and 59 healthy age- and IOP-matched controls were included in this prospective clinical study. To define a discrimination index, Corvis ST data (Oculus GmbG, Wetzlar, Germany) of one eye were used as training dataset. DCR parameters were analyzed successively until the best discriminant between NPG patients and controls was reached. Fellow eyes of NPG patients were used as test dataset. For statistical calculation, the discriminant analysis of SPSS 24 (IBM, NY, USA) was used.
Results :
The Dresden BGI was calculated using 12 DCR parameters, with outward applanation velocity, stiffness parameter at highest concavity, integrated radius, peak distance and highest concavity time being the most significant ones. In the training dataset, with a cut-off value of BGI=0.1475, 91.5% of healthy subjects were correctly identified as healthy and 81% of NPG patients correctly as having glaucoma. The receiver operating characteristic (ROC) curve showed an area under the curve (AUC) of 0.906 with a sensitivity of 81% and a specificity of 90%. In the test dataset, the ROC curve showed an AUC of 0.830 with a sensitivity of 68% and a specificity of 92%.
Conclusions :
This new Dresden BGI shows to be highly sensitive and specific to discriminate healthy from NPG eyes. Since diagnosis of NPG is often challenging, the Dresden BGI may help in the diagnosis of NPG in everyday clinical practice.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.