Agreement of Flicker Chronoscopy for Structural Glaucomatous Progression Detection and Factors Associated With Progression

Abstract

To evaluate agreement of flicker chronoscopy for structural glaucomatous progression detection and factors associated with progression. Retrospective cohort study. Two glaucoma fellowship-trained ophthalmologists, masked to temporal sequence, independently graded serial flicker chronoscopy images from 1 eye of a cohort of glaucoma patients for features of structural progression. Agreement between graders was determined, as was accuracy for determining the temporal order of images. After adjudication, simple and multiple logistic models were constructed to determine baseline variables associated with increased odds of progression. Fifty of 103 included eyes/patients (48.5%) had at least 1 sign of structural progression. Temporal sequence was incorrectly determined in 14 of 206 cases (6.4%). Interobserver agreements for identifying baseline photographs (κ= 0.9), global progression (κ= 0.7), parapapillary atrophy (PPA) progression (κ= 0.7), disc hemorrhages (κ= 0.7), neuroretinal rim loss (κ= 0.5), and retinal nerve fiber layer (RNFL) loss (κ= 0.2) were calculated. Age was significantly associated with global (1.8; 1.3-2.6, P < .001) (odds ratio; 95% confidence interval, significance) and PPA progression (1.7; 1.2-2.4, P= .002). Lower corneal hysteresis was associated with global progression (0.78; 0.56-0.99, P= .049) and RNFL loss (0.5; 0.3-0.9, P=.02). Goldmann-correlated intraocular pressure (1.0, 0.7-1.4, P= .9), visual field mean deviation (1.0, 0.9-1.0, P= .2), and central corneal thickness (0.9, 0.8-1.0, P= .1) were not significantly associated withprogression. On multivariable analysis, only age was associated with global progression (1.8; 1.2-2.5, P= .002). Flicker chronoscopy demonstrated acceptable interobserver agreement in structural progression detection. Corneal hysteresis and age were both associated with progression, but age was the only significant factor on multivariable analysis.