Performance of GDx and HRT in the Finnish Evidence-Based Guideline for Open-Angle Glaucoma

Abstract

Aim: To compare the performance of Heidelberg retina tomograph (HRT) and scanning laser polarimetry (GDx) with photographic evaluation of the optic nerve head (ONH) and retinal nerve fiber layer (RNFL) in the application of the Finnish Evidence-Based Guideline for Open-Angle Glaucoma.

Methods: A total of 41 control participants and 312 patients referred for glaucoma evaluation were included in the study. All the participants underwent ophthalmic evaluation, ONH stereophotography, monochromatic RNFL photography, HRT, optical coherence tomography, and GDx evaluation. Participants were classified on the basis of stereophotographic or imaging device results based by applying the Finnish Guideline.

Results: Agreement between the stereophotographic evaluation and that on the basis of the imaging devices was 52.9%. Classification of patients with similar management advice on the basis of these evaluations had 56.4% agreement. The specificity of the Finnish guideline for detecting normal patients was 78% (stereophotography) and 83% (imaging devices). Optic disc size interfered with the diagnosis in patients evaluated using the HRT3 glaucoma probability score. Structural changes were more frequently detected before functional changes.

Conclusion: The Finnish Evidence-Based Guideline for Open-Angle Glaucoma is useful for classifying normal participants and patients with suspected glaucoma or glaucoma through either conventional stereophotographic evaluation of the neuroretinal structures or with the new imaging devices.