Association of Structural and Functional Measures with Contrast Sensitivity in Glaucoma

Abstract

PURPOSE

To test the hypothesis that structural and functional measures predict contrast sensitivity (CS) outcomes in glaucomatous eyes.

DESIGN

Cross-sectional prospective study.

METHODS

105 eyes of 65 patients who underwent macular SD-OCT imaging, 24-2 standard achromatic visual fields (VF) and CS measurement on the same day were enrolled. Association of CS at 4 spatial frequencies (3, 6, 12 and 18 cycles per degree, cpd), with structural and functional outcomes was explored with correlation and regression analyses.

RESULTS

The median (IQR) 24-2 visual field mean deviation was −7.6 (−11.1 to −3.0). Significant correlations were found between CS at 6 cpd and ganglion cell/inner plexiform layer thickness at inferotemporal and inferonasal macular sectors (ρ =0.222, p=0.023 and ρ =0.209, p=0.032, respectively). CS at 6 cpd demonstrated higher correlations with full macular thickness measurements, the strongest of which was with the central macular thickness in the superior 6×3 degree region (ρ =0.311, p=0.001). Contrast sensitivity at 6 cpd also had the strongest correlation with mean deviation of the 4 central VF points (ρ=−0.420; p<0.001). There was a significant correlation between logMAR visual acuity and contrast sensitivity at 6, 12, and 18 cpd (ρ =−0.306, −0.348 and −0.241, p<0.013, respectively).

CONCLUSIONS

Structural and functional measures showed a fair relationship with contrast sensitivity. This association was most prominent between full thickness macular measures or central VF parameters and CS at 6 cpd. Contrast sensitivity was not a reliable surrogate for glaucoma severity in this cross-sectional study.