Visual Function-Specific Perimetry to Identify Glaucomatous Visual Loss Using Three Different Definitions of Visual Field Abnormality

Abstract

To compare the most recent versions of standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), and frequency-doubling technology (FDT) using three definitions of visual field (VF) abnormality: single-test abnormality, abnormality confirmed by the same test, and abnormality confirmed by a different test. Data obtained from one eye of each of 174 patients with glaucoma and 164 age-matched healthy control subjects from the Diagnostic Innovations in Glaucoma Study and African Descent and Glaucoma Evaluation Study were included, based on the appearance of the optic disc on stereophotographs. Each participant had two reliable 24-2 SAP-SITA, SWAP-SITA, and Matrix FDT tests. Receiver operating characteristic (ROC) curves were generated for the PSD of each test to equate the tests at 90% and 95% specificity. SAP, SWAP, and FDT were compared under each definition of VF abnormality by assessing the sensitivities, the agreement between tests and the overlap in deficit location at these set specificities. The tests were also compared using the machine-derived PSD. At a set specificity of 95%, single-test sensitivities of 30% (SAP), 29% (SWAP), and 28% (FDT) were observed (all P > 0.05). Sensitivities ranged from 24% to 27% (all P > 0.05) when same-test confirmation was used and from 20% to 23% (all P > 0.05) when different-test confirmation was used. SAP/SAP sensitivity was higher than all different-test combinations (all P < 0.05), and SWAP/FDT sensitivity was lower than all same-test combinations (all P < 0.05). Confirming VF abnormality is important and optimal when an abnormal SAP is confirmed by a subsequent SAP or SWAP test.