Abstract
Purpose: :
To determine the combination of functional and structural tests that will identify progression of glaucomatous damage.
Methods: :
Ninety eyes of 46 patients with glaucoma were enrolled in a prospective study. Fifty-seven eyes had either disc hemorrhage or pseudoexfoliative glaucoma. Testing procedure involved 2 baseline and 3 follow-up examinations at 6-month intervals. At each visit the following tests were performed: 24-2 Matrix frequency doubling (FDT) perimetry, 24-2 Humphrey visual fields (HVF), multifocal visual evoked potentials (mfVEP); pattern electroretinography (PERG) and OCT 3 measurements of optic nerve head topography. Stereo disc photography was obtained at baseline and at the final examination. To identify progression, the 2 baseline measurements for the following were averaged: mean deviation (MD) and pattern standard deviation (PSD) for FDT and HVF, response amplitudes for PERGs, number of abnormal test locations in each hemifield with probability values of 1% and 5% for the mfVEP, and retinal nerve fiber layer (RNFL) thickness for the OCT. These values were compared to those obtained at the final examination. Two glaucoma experts compared baseline to final stereo disc photographs to identify progression.
Results: :
Fifty-nine eyes of 30 patients were followed for the two-year period; 4 patients were scheduled for the final examination, and 12 patients were lost to follow-up. For HVF, there were significant changes in MD and PSD values suggesting progression in 12 (20.3%) eyes for MD, but in only 4 (7.0%) for PSD. For FDT, there were significant changes in MD in 11 (18.7%) eyes, but in only 1 (1.7%) for PSD. Five (8.5%) eyes showed changes in MD for both visual field methods. For the mfVEP, there was a significant increase in abnormal points in 18 (30.5%) eyes. Seven eyes did not show significant visual field changes. For PERG, response amplitudes were decreased in 3 (5.1%) eyes. For OCT, RNFL average thickness values were decreased for 15 (25.4%) eyes. Nine out of 48 (18.8%) eyes showed progression on stereo photography; 4 were normal on all functional and structural tests and only 2 showed changes on OCT.
Conclusions: :
Progression was evident on HVF(MD), FDT(MD), mfVEP and OCT. However the agreement among tests and stereo photography regarding which eyes showed progression was poor. These discrepancies illustrate the importance of following patients with a combination of functional and structural tests, as well as, the need to better understand the relationship among tests.
Keywords: visual fields • electrophysiology: clinical • imaging/image analysis: clinical