Scanning laser polarimetry and confocal scanning laser ophthalmoscopy: technical notes on their use in glaucoma.

The mere intraocular pressure (IOP) measurement and the visual field (VF) examination do not allow early primary open-angle glaucoma (POAG) diagnosis. At present, the morphological and morphometric analysis of the optic disk is considered very important for an early diagnosis and follow-up of the disease. The recent introduction of laser systems equipped with new polarimetry techniques (GDx) and confocal tomography (HRT) allows an objective, quantitative, and reproducible evaluation of the morphometry and morphology of the optic disk and retinal nerve fiber layer (RNFL). The GDx, scanning laser polarimetry, studies the RNFL. The HRT, confocal scanning laser tomography, examines several optic disk and peripapillar area parameters. These devices allow obtaining objective and quantitative data concerning RNFL and optic nerve head. They represent complementary and important examinations in case of uncertain POAG diagnosis. The correct evaluation of the parameters studied by these techniques and the knowledge of the instruments' limits are needed for an adequate interpretation of the results obtained.