Frequency doubling technology for earlier detection of functional damage in standard automated perimetry-normal hemifield in glaucoma with low-to-normal pressure.
ABSTRACT To compare the longitudinal change of frequency doubling technology (FDT) perimetry and standard automated perimetry (SAP) results in SAP-normal hemifield in open-angle glaucoma (OAG) eyes with low-to-normal intraocular pressure (IOP).
FDT perimetry with the N-30 full threshold protocol and SAP using the Humphrey Field Analyzer with the 30-2 Swedish Interactive Threshold Algorithm-standard protocol were periodically performed for at least 3 years in 39 eyes of 39 OAG patients with low-to-normal IOP and visual field damage confined to only one hemifield. The time courses of the mean of the threshold values of FDT and the mean of total deviations (TDs) in SAP-normal and SAP-abnormal fields were analyzed using a linear mixed model.
The average follow-up was 4.9 years and the average IOP during follow-up was 12.6 mm Hg with or without medication. The aging effect-corrected rate of change in the mean FDT threshold values was significantly negative (P=0.004) in the SAP-normal hemifield, whereas that of mean of TD values by SAP did not significantly differ. In the SAP-abnormal hemifield, the rate of change was significantly negative for both tests (P<0.001). The mean of the slope of the mean TD values in the SAP-abnormal hemifield was significantly more negative than that in the SAP-normal hemifield (P=0.011), whereas that of the mean FDT threshold values showed no significant difference between the 2 hemifields.
FDT is useful for monitoring functional damage in the SAP-normal hemifield in OAG eyes with low-to-normal IOP.
- SourceAvailable from: InTech11/2011; , ISBN: 978-953-307-591-4
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ABSTRACT: To evaluate the relationship and agreement between standard automated perimetry (SAP) and Matrix frequency doubling technology (Matrix-FDT) in subjects with ocular hypertension and healthy control subjects. Forty-four eyes of 44 ocular hypertensive subjects and 29 eyes of 29 healthy age-matched control subjects were included in this prospective study. All participants underwent complete ophthalmic examination, including slit-lamp biomicroscopy, intraocular pressure measurement, pachymetry, and dilated fundus examination, and showed reliable visual field tests. One randomly selected eye of each participant was examined with SAP (Swedish Interactive Threshold Algorithm [SITA] Standard 24-2 test) and Matrix-FDT (24-2 threshold test), in random order. Correlations between global indices (MD, PSD), regions (2 hemifields, 4 quadrants, 6 sectors) and 52 single field positions were analyzed using Spearman's rank correlation coefficient. In both groups, mean deviation values of SAP and Matrix-FDT correlated significantly (OHT subjects: r = 0.47, p<0.005; healthy subjects: r = 0.68; p<0.001, respectively). Pattern standard deviation of SAP and Matrix-FDT showed no significant correlation in healthy subjects but correlated significantly in ocular hypertensive subjects (r = 0.45, p<0.005). In healthy subjects, a significant correlation between SAP and Matrix-FDT was shown in the supero-temporal and infero-temporal sectors of the disc (r = 0.40 and r = 0.38, p<0.05, respectively). In OHT subjects, supero-temporal, supero-nasal and nasal sectors correlated significantly (r = 0.49, 0.62 and 0.38, p≤0.01, respectively). The correlation pattern of individual visual field test locations appeared heterogeneous in both groups. In both, ocular hypertensive and healthy subjects SAP and Matrix-FDT correlate well. In ocular hypertensive subjects, both techniques showed good correlation in the supero-temporal, supero-nasal, and nasal sectors of the disc. Poor agreement was found in the temporal, infero-temporal and infero-nasal disc sectors. This missing correlation might be related to early retinal nerve fiber layer damage in these regions of the disc, recognized by one of the visual field instruments.PLoS ONE 01/2013; 8(2):e57663. · 3.73 Impact Factor