Estimating the Usefulness of Humphrey Perimetry Gaze Tracking for Evaluating Structure-Function Relationship in Glaucoma.

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.