Corneal biomechanics in normal Saudi individuals

The aim of this study was to determine and relate corneal biomechanical metrics with demographic, tomographic and refractive data in healthy Saudi people.

Prospective, cross-sectional, observational study.

The study included 215 normal Saudi adult individuals.

Corneal hysteresis (CH) and corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated intraocular pressure (IOPcc) were measured by ocular response analyzer. The central keratometry (CK), central corneal thickness (CCT), and anterior chamber depth (ACD) were measured using Pentacam system. The spherical equivalent of refraction (SER) was obtained by an Auto-refractometer.

The mean CH was 11.16 ± 2.11, CRF was 11.07 ± 2.31 and IOP was 15.12 ± 3.5. Mean CK, ACD, CH and CRF were distinct among gender with the significant P values of 0.05, 0.006, 0.020, and 0.047 respectively. CRF was negatively correlated with ACD (r = -0.146, P = 0.032). A positive correlation was found between CRF and SER (r = 0.176, P = 0.010), CCT (r = 0.447, p = 0.000) and CH (r = 0.878 and p = 0.000). CH was negatively correlated with IOPcc (-0.433, p = 0.000). A positive correlation was found between CH and ACD (r = -0.14, p = 0.044), SER (r = 0.617, p = 0.014), CCT (r = 0.412, p = 0.000) and IOPg (r = 0.183, p = 0.007).

This study demonstrated a distinct difference among gender values of corneal hysteresis and corneal resistance factor being higher in female Saudi subjects. CH and CRF values were higher in Saudi subjects than values in other populations. This may suggest the presence of ethnic differences in ocular parameters and support the importance of establishing population norms for corneal biomechanical parameters.