Accuracy of scanning laser polarimetry, scanning laser tomography in a glaucoma screening trial

Abstract

Abstract Purpose: To compare the usefulness of scanning laser polarimetry (GDx‐VCC), scanning laser tomography (HRT) and their combined evaluation in glaucoma screening. Methods: In a non‐population‐based pre‐publicized trial, self‐recruited Caucasian participants were screened for glaucoma with GDx‐VCC, HRT, and by independent clinical examination. Cases with possible glaucoma as found with any of the screening methods underwent a detailed clinical investigation to verify or exclude glaucoma. Results: Of the 136 attendees 118 participants (218 eyes) successfully underwent the GDx‐VCC and HRT II measurements. Twenty‐three eyes of 13 participants had glaucoma. Seventeen glaucomatous eyes had early damage. Evaluated separately, the GDx‐VCC screening test (borderline=normal) performed best with 7.5 positive likelihood ratio (PLR). PRL for all HRT parameters was <3.7. Combining different threshold criteria, for GDx‐VCC PLR increased to 14.0‐17.7, but no useful increase was seen for HRT (PRL<4.7 for all combinations). Combination of the best HRT and GDx‐VCC criteria resulted in PRL increase compared to the HRT combinations, but PRL decrease compared to the GDx‐VCC combinations (PRL<12.7 for all combinations). Conclusions: In this population with relatively high risk for mild glaucomatous damage, a combination of different GDx‐VCC criteria but not HRT criteria or combinations containing HRT criteria were useful for glaucoma screening.