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.

Performance of Imaging Devices versus Optic Disc and Fiber Layer Photography in a Clinical Practice Guideline for Glaucoma Diagnosis

“…Similar to other studies (7, 8), the participants were not selected by applying a gold standard glaucoma test. Because glaucoma cannot be defined outside the context of structure and function, and both structure and function were being evaluated in this study, the use of a structural or functional gold standard could induce a bias.…”

“…Application of the FEBG-OAG classifies the subjects into several groups, including those with normal findings, and several groups with suspected glaucoma or glaucoma. Similar to other studies (7,8), the participants were not selected by applying a gold standard glaucoma test. Because glaucoma cannot be defined outside the context of structure and function, and both structure and function ommendations for glaucoma management, such as the European Glaucoma Society Guidelines, the American Academy of Ophthalmology Preferred Practice Patterns for Open-Angle Glaucoma, and the Finnish Evidence-Based Guideline for Open-Angle Glaucoma (FEBG-OAG) (4)(5)(6).…”

Scanning Laser Topography and Scanning Laser Polarimetry: Comparing Both Imaging Methods at Same Distances from the Optic Nerve Head

“…The latest method, called enhanced corneal compensation (ECC), is said to have further improved the evaluation of the RNFL by the SLP device and, according to recent studies [4, 5] has increased both the diagnostic accuracy and the correlation between functional and structural measurements. Recent research indicates that there is still a large gap between the diagnostic conclusions reached using these modern imaging devices and the clinical assessment: a study of 312 glaucoma patients and 41 control participants by Pablo et al ., [6] found that the agreement between the stereophotographic evaluations and the conclusions based on SLT and SLP was just 52.9%. Medeiros et al, [7] could show already SLP with VCC to be superior to these techniques, and that the new SLP ECC technology again is an advantage in image quality and provides an increased ability to detect early glaucomatous damage and even small changes [8].…”