Abstract
Purpose::
To compare frequency doubling perimetry (FDT), standard automated perimetry (SAP), multifocal visual evoked potentials (mfVEPs), pattern electroretinography (PERG) and optical coherence tomography (OCT) in glaucoma and evaluate the reproducibility of the measurements.
Methods::
Sixty-six eyes of 34 subjects with open-angle glaucoma and corrected visual acuity of >=20/40 were enrolled in a prospective study. To assess reproducibility and establish baseline measurements all patients were tested twice within a period of one month. At each visit FDT was performed with the Humphrey Matrix (24-2 program, ZEST), SAP with the Humphrey Field Analyzer II (24-2 program, SITA), mfVEPs with VERIS system using a 60 sector pattern-reversal dartboard array, PERGs with Glaid (LACE Elettronica) and optic disc and retinal nerve fiber layer assessments with OCT3. Reproducibility of each test was assessed by the following: mean deviation (MD) and pattern standard deviation (PSD) for FDT and SAP, response amplitudes and phase for PERGs, number of abnormal test locations with probability values of 1% and 5% for mfVEPs, and thickness of the superior and inferior quadrants and overall average thickness for the OCT.
Results::
The MD and PSD of the FDT and SAP were highly correlated (r>0.9) for the two visits, as were the number of abnormal test locations for the mfVEP, and thickness values for the OCT3 (r>0.9). The relationship was weaker for the PERG (phase r=0.8, amplitude r=0.6). A comparison between the global indices for the FDT and SAP showed a close linear relationship (MD r>0.9, PSD r>0.8). Qualitatively there was good agreement among the three functional visual field measures and structural tests regarding the presence of an abnormality (agreement>76%), and good agreement regarding the location of the deficit.
Conclusions::
The good reproducibility and agreement among these different functional and structural tests supports their use in a prospective study designed to detect glaucomatous progression.
Keywords: electrophysiology: clinical • imaging/image analysis: clinical • visual fields