Abstract
Purpose: :
To evaluate the correlation and the clinical agreement among standard automated perimetry (SAP; Humphrey Field Analyzer 750 - HFA; Carl Zeiss Meditec Inc.), Frequency Doubling Technology (FDT; Welch Allyn Inc., Skaneateles, NY; Zeiss - Humphrey, San Leandro, CA) and Rarebit Perimetry (RBP) in glaucoma patients by a cross-sectional study.
Methods: :
Thirty-six consecutive patients with primary-open angle glaucoma (POAG) were included in this study. One eye of each patient was randomly chosen for data analysis. Visual fields were assessed by SAP (HFA 30-2 full-threshold program), FDT (full-threshold C-20 program) and RBP (Rabbit Visual Field Test program). Mean deviation (MD) and pattern stantdard deviation (PSD) of both HFA and FDT were considered for the analysis. Among RBP parameters, mean hit ratio percentage (MHR-%), mean hit ratio standard deviation (MHR-sd), number of hit ratio (num-HR), hit ratio percentage (HR%), hit ratio standard deviation (HR-sd), time test and mean reaction time (MRT) were considered. The data were analyzed by descriptive analysis and Pearson’s r coefficient was used to correlate perimetric results and Bonferroni correction was applied. Kappa statistic was used to study the agreement among the three different techniques.
Results: :
The average HFA-MD and HFA-PSD values were -1.86 db ± 4.7 (mean ± standard deviation) and 3.6 db ± 4.3 respectively. The average FDT-MD and FDT-PSD were -4.62 db ± 4.95 and 5.88 ± 3.10. The mean RBP-MHR was 70.40% ± 19.50. Significant correlation was found between HFA-MD and FDT-MD (r = 0.651, P < 0.001), HFA-PSD and FDT-PSD (r = 0.936, P < 0.001). The most significant correlations between HFA and RBP were found between HFA-MD and MHR-% (r = 0.757, P < 0.001), HFA-MD and MHR-SD (r = - 0.761, P < 0.001) and HFA-PSD and MHR-SD (r = 0.738, P < 0.001). The most significant (P < 0.001) correlations among FDT and RBP parameters were observed between FDT-MD and MHR-% (r = 0.791) and FDT-PSD and MHR-SD (r = 0.720). The agreement between FDT and HFA and between HFA and RB was poor (Kappa = 0.194 and 0.138 respectively), while the agreement between FDT and RBP was slight (Kappa = 0.273).
Keywords: perimetry • ganglion cells