Contrast Rivalry Paradigm Reveals Suppression of Monocular Input in Keratoconus

Purpose: Keratoconus results in image quality loss one or both eyes due to increased corneal distortion. This study quantified the depth of monocular suppression keratoconus this using a binocular contrast rivalry paradigm. Methods: Contrast was induced 50 keratoconic cases (11–31 years) and 12 age-matched controls by dichoptically viewing orthogonal Gabor patches 5 cycles per degree (cpd) 1.5 cpd spatial frequency for 120 seconds with their best-corrected spectacles rigid gas permeable (RGP) contact lenses. The dwell time on each eye's percept determined at baseline (100% bilaterally) varying levels (80–2.5%) stronger eye dominant controls. reduction needed balance times considered measure depth. Results: At stimuli spectacle correction, switches were less frequent biased toward cases, all relative (P < 0.001). point (20.51% [10.7–61%]) lower than (99.80% [98.6–100%]; P 0.001) strongly associated overall interocular difference disease severity (r = 0.83, reduced (70.8% [21.7–94%]), stimulus lenses (80.1% [49.5–91.7%]), 0.001). Conclusions: lesser dominates keratoconus. poorer depends extent bilateral severity, optical correction modality, target frequency.