Corneal Stress Distribution Evolves from Thickness-Driven in Normal Corneas to Curvature-Driven with Progression in Keratoconus

PurposeTo introduce the novel parameter of Corneal Contribution to Stress and compare stress distribution patterns between keratoconus normal corneas.DesignProspective, Observational, Cross-sectional StudyParticipantsThe study included 66 eyes 40 subjects diagnosed with (KCN) 155 left from control (NRL) subjects.MethodsTomography was obtained calculate newly proposed (CCS), defined according hoop formula without intraocular pressure, R/2t, where R is radius curvature t thickness. CCS maps were calculated pachymetry tangential maps. Custom software identified 2mm diameter zones greatest (Cspot-max), thinnest (Pach-min), (CCSmax), lowest (CCSmin). difference (CCSdiff) as CCSmax – CCSmin. Distances Cspot-max vs Pach-min, CCSmax, CCSmin, well Pach-min CCSmin calculated. T-tests performed cohorts paired within cohorts. Univariate linear regression analyses parameters distances. Significance threshold p < 0.05.Main Outcome MeasuresCorneal parameters, corneal features maximum curvature, minimum thickness, distances features.ResultsCCSmax significantly closer (0.79 ± 0.92) (2.04 0.85) than (3.17 0.38, 2.73 1.53, respectively) in NRL, 0.0001, while (1.35 1.43) (2.52 0.72) KCN, 0.0001. (severity) related CCSdiff KCN (p 0.0001; R2 = 0.5882) a weak relationship NRL 0.0080, 0.0451). distance 0.3737) significance 0.8011).ConclusionsCorneal driven by thickness at curvature. However, moves away progression associated Severity greater stress, consistent biomechanical cycle decompensation.