Detection of glaucoma using scanning laser polarimetry with enhanced corneal compensation

To evaluate and compare the diagnostic accuracies for glaucoma detection of scanning laser polarimetry (SLP) with enhanced corneal compensation (GDx ECC) and variable corneal compensation (GDx VCC; both by Carl Zeiss Meditec, Dublin, CA), according to different levels of disease severity and presence of atypical retardation patterns.

The study included 102 eyes of 68 patients with glaucoma and 94 eyes of 55 normal subjects. All patients underwent SLP imaging with ECC and VCC methods on the same day. Severity of disease was based on the AGIS (Advanced Glaucoma Intervention Study) visual field score. An ROC regression model was fitted to evaluate the influence of disease severity and atypical retardation patterns (typical scan score [TSS]) on the diagnostic performance of the SLP parameters for both methods.

GDx ECC performed significantly better than GDx VCC in glaucoma detection in patients with more severe atypical retardation patterns. For average disease severity and arbitrarily chosen TSS values of 20, 50, 70, and 100, the ROC curve areas for GDx ECC were 0.910, 0.935, 0.948, and 0.964. Corresponding values for GDx VCC were 0.684, 0.850, 0.920, and 0.975. For lower values of TSS and lower AGIS scores, GDx ECC performed significantly better than GDx VCC.

GDx ECC performed significantly better than VCC for diagnosing glaucoma in patients with more severe atypical patterns of retardation and at earlier stages of disease.