Purpose
A combination of structural and functional tests is used in glaucoma daily clinics to increase diagnostic sensitivity and ability to detect progression. Understanding their comparative roles and performance in clinical practice is key to the management of glaucoma. A prospective, cross-sectional study was developed to evaluate and compare the diagnostic accuracy of Humphrey perimetry (HFA), Octopus perimetry (OP), and spectral-domain optical coherence tomography (OCT) to discriminate between healthy and glaucoma subjects.
Methods
One hundred fifty eyes of 150 open-angle glaucoma patients and 88 eyes of 88 healthy individuals were consecutive and prospectively selected. Eligible subjects for the glaucoma group had to have intraocular pressure higher than 21mmHg and glaucomatous optic nerve head morphology. All participants underwent a reliable standard automated perimetry with the HFA (Humphrey Field Analyzer 750i, Zeiss Humphrey Systems, Dublin, CA; 24-2 SITA Standard strategy) and with the OP (Octopus 1-2-3, Haag Streit International, Köniz, Bern, Switzerland; G1 TOP strategy), as well as imaging with the Cirrus OCT (Carl Zeiss Meditec, Dublin, Ca; Optic Disc Cube 200x200 scanning protocol). Left eyes were converted to a right eye format. The receiver operating characteristic (ROC) curves were plotted for the parapapillary retinal nerve fiber layer thicknesses and the optic nerve head parameters acquired with OCT and for the HFA and OP outcomes. Sensitivities at 85% and 95% fixed-specificities were also calculated. The best areas under the ROC curves (AUCs) were compared using the DeLong method.
Results
Mean deviation (MD) of HFA (0.966; p<0.001), Mean Sensitivity (MS) of OP (0.941; p<0.001) and the average Cup/Disc ratio measured by Cirrus OCT (0.958; p<0.001) had the largest AUCs for each studied test. There were not significant differences between them. At 85% fixed specificity the best parameter to discriminate between controls and glaucoma’s was the Visual Field Index (VFI) of HFA (93.3% sensitivity) and at 95% fixed specificity the best parameter to discriminate between control and glaucoma eyes was the pattern standard deviation (PSD) of HFA (82.0% sensitivity).
Conclusions
HFA, OP and Cirrus OCT presented very good and similar diagnostic accuracy for glaucomatous optic neuropathy.