Oculus-Spark perimetry compared with 3 procedures of glaucoma morphologic analysis (GDx, HRT, and OCT)

To compare diagnostic capabilities and agreement between Oculus-Spark perimetry and 3 procedures of glaucoma morphologic analysis.

A total of 102 normal eyes and 104 consecutive eyes with suspected or confirmed glaucoma (1 eye per subject) were analyzed in a prospective observational case-control study, using Spark strategy (Oculus Easyfield Perimeter), Heidelberg retinal tomograph (HRT), Zeiss laser polarimetry (GDx), and Cirrus optical coherence tomography (OCT).

Spark first phase lasted 37 seconds and all 4 phases 2:34 minutes. Specificities and sensitivities were as follows: Spark mean deviation (MD) first phase (95.1%, 85.6%), MD second and final phases (95.1%, 86.5%), GDx-nerve fiber indicator (95.1%, 57.4%), HRT-Reinhard Burk discriminant function (95.1%, 52.9%), HRT glaucoma probability score (95.1%, 71.2%), Cirrus OCT vertical cup/disc ratio (96.1%, 85.6%), and Cirrus OCT retinal nerve fiber layer thickness (95.1%, 68.0%). Diagnostic agreement between second and final Spark MD phases was kappa=0.92; between phase 1 Spark/MD and Cirrus OCT/vertical C/D ratio was kappa=0.78. Agreements between the 2 Cirrus OCT indices was kappa=0.69 and between the 2 HRT indices was kappa=0.559. The correlation coefficient between second and final MD and PSD was 0.99, and 0.98 between the number of scotomatous points. There was high concordance in scotoma position in both phases (kappa=0.86). The linear correlation coefficients between the morphologic indices were 0.48-0.78, and between morphologic and functional indices 0.51-0.76. Correlation coefficients comparing morphologic and functional indices were similar in the first and the last phase (p>0.05 in all cases).

Spark perimetry appears to show useful sensitivity and specificity, even in the first phase, and good agreement with the morphology.