A Comparison of Objective and Subjective Quantitative Parameters at the Initial Visit to Predict Future Glaucomatous Visual Field (VF) Progression

Abstract

Purpose: : To compare the disc damage likelihood scale (DDLS), vertical cup/disc ratio (VCD), and quantitative parameters from optical coherence tomography (OCT) and confocal scanning laser ophthalmoscopy (CSLO) in predicting future glaucomatous VF progression.

Methods: : A retrospective analysis on 86 eyes of 47 subjects with ≥5 VF tests (SITA Standard 24-2; Carl Zeiss Meditec Inc., (CZMI), Dublin, CA) and single baseline measures from disc photos (Nidek 3-Dx; Nidek, Gamagori, Japan), OCT (StratusOCT; CZMI), and CSLO (Heidelberg Retina Tomography (HRT); Heidelberg Engineering, Heidelberg, Germany) all acquired within 6 months of each other. DDLS and VCD were determined by the average independent opinion of 3 glaucoma experts. VF progression was defined by the glaucoma progression analysis (GPA) and visual field index (VFI) slope significance provided by the machine. A generalized estimating equation was used to identify the predictive capabilities of each method for future VF progression.

Results: : Median follow-up time was 4.2 years (range 2.1 to 10.3 years). Nine eyes progressed based on GPA and 6 by VFI. The strongest predictors of future GPA progression were the OCT retinal nerve fiber layer (RNFL) thickness at 6 o’clock and the HRT global mean cup depth (p=0.011 for both). The strongest predictors of future VFI progression were HRT global cup to disc ratio (p=0.006), global rim and disc area, and OCT RNFL thickness globally, in each quadrant, and 8 o’clock.

Conclusions: : Objective quantitative structural imaging was a stronger predictor of future glaucomatous VF progression than expert subjective optic nerve head assessment.

Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic nerve