ABSTRACT
PURPOSE: We have previously reported that fixation loss (FL) rates, false-positive (FP) rates, and gaze tracking (GT) parameters (average tracking failure frequency per stimulus [TFF], average blinking frequency [BF], average frequency of eye movements between 1° and 2° [move1-2], between 3° and 5° [move3-5], and equal to or more than 6° [move≥6]) are related to the over- or underestimation of visual field (VF) results. The purpose of the current study was to validate these results by investigating the effect of implementing the GT parameters on the relationship between VF results and optical coherence tomography (OCT) measurements. METHODS: Two hundred forty-four eyes of 155 open-angle glaucoma patients were included. Vision fixation during VF tests with the Humphrey Field Analyzer (24-2 SITA standard) was evaluated using the gaze fixation chart at the bottom of the VF printout. Mean total deviation (mTD) values were calculated, and their relationship with OCT-determined circumpapillary retinal nerve fiber layer (cp-RNFL), OCT-determined macular ganglion cell complex (GCC) thickness, and axial length was investigated using the corrected Akaike Information Criterion (AICc) in linear mixed modeling. RESULTS: In the best model, average total cpRNFL thickness, average total GCC thickness, axial length, FL, FP, move3-5, move≥6, TFF, and BF were selected as significant predictors (mTD = 2.1 + 0.097 × average total cpRNFL thickness + 0.089 × average total GCC thickness - 0.94 × axial length + 2.7 × FL + 7.2 × FP - 7.0 × move3-5 - 1.8 × move≥6 - 4.2 × TFF - 1.7 × BF). CONCLUSIONS: Both GT parameters and classic VF reliability indices had significant influence on the structure-function relationship analysis in glaucoma.
ABSTRACT
PURPOSE: We evaluated the usefulness of gaze tracking (GT) results as an index of visual field reliability in glaucoma. METHODS: The study population consisted of 631 eyes of 400 patients with open angle glaucoma in an institutional practice, with 10 visual fields (VFs). For the observational procedure, visual fixation was assessed using the gaze fixation chart at the bottom of the VF (Humphrey Field Analyzer, 30-2 SITA standard) printout. Average frequency of eye movement between 1° and 2° (move(1-2)), 3° and 5° (move(3-5)), and greater than or equal to 6° (move(≥6)) were calculated. In addition, average tracking failure frequency (TFF) and average blinking frequency (BF) were calculated. The relationship between mean deviation (MD), fixation losses (FLs), false-positives (FPs), false-negatives (FNs), move(1-2), move(3-5), move(≥6), TFF, BF, and pattern standard deviation (PSD) were evaluated using linear modeling. Main outcome measures included parameters related to over- or underestimation of MD values. RESULTS: Patients' mean MD progression rate was -0.23 dB/y. The best model to predict MD values included FL rate, FP rate, move(3-5), move(≥6), TFF, BF, and PSD as dependent variables with coefficients of 0.90, 9.2, -0.57, -0.52, -2.2, -1.1, and -0.56, respectively (P < 0.001). CONCLUSIONS: High FL and FP rates tend to raise MD values. By contrast, high values of move(3-5), move(≥6), TFF, BF, and PSD tend to lower MD values. Thus, GT parameters can be used as new indices of VF reliability through the prediction of over- or underestimation of VF results.
Subject(s)
Glaucoma, Open-Angle/diagnosis , Visual Field Tests/methods , Visual Fields , Disease Progression , Female , Glaucoma, Open-Angle/physiopathology , Humans , Male , Middle Aged , Reproducibility of ResultsABSTRACT
PURPOSE: To develop a novel method to evaluate gaze tracking (GT) results and to examine their relationship with test-retest reproducibility of visual field (VF) measurements. METHODS: Subjects comprised of 42 eyes of 42 glaucoma patients. Vision fixation during VF tests with the Humphrey Field Analyzer was evaluated using the gaze fixation line chart at the bottom of the VF printout. We defined some GT parameters as follows: average tracking failure frequency per stimulus (TFF), average frequency of eye movements between 1° and 2°, 3° and 5°, and more than 6°. Humphrey VFs (24-2 and 10-2 Swedish Interactive Threshold Algorithm [SITA] standard) were prospectively examined twice within a period of 3 months in 42 glaucoma patients. Mean absolute variability of total deviation (TD) values in the test-retest VFs was measured and its relationship to fixation losses (FLs), false positives (FPs), false negatives (FNs), mean deviation (MD), and pattern standard deviation (PSD) was investigated using the corrected Akaike Information Criterion (AICc) from linear modeling. RESULTS: The best model to predict test-retest variability in the 24-2 VF included PSD, TFF, and FNs as dependent variables, while the best model for the 10-2 VF included PSD and average frequency of eye movements between 3° and 5° (P < 0.05 for all coefficients). CONCLUSIONS: Gaze tracking parameters are closely related to the reproducibility of VF results, and it would be beneficial to objectively use these parameters when estimating the reliability of VF tests.
