<h4>PURPOSE</h4><p>To evaluate corneal biomechanical metrics with tomographic parameters (given by the Oculus Pentacam) and refractive data in a population of healthy Brazilian patients.</p>
<h4>METHODS</h4><p>Observational, cross-sectional study of 150 consecutive patients (53 men and 97 women; 260 eyes). Age, gender, central keratometric readings (central K), central corneal thickness (CCT), anterior chamber depth (ACD), spherical equivalent refraction, corneal hysteresis, and corneal resistance factor (CRF) were assessed and analyzed. </p>
<h4>RESULTS</h4><p>Mean patient age was 46.5±21.04 years, average central K was 43.59±1.54 diopters (D), CCT was 545.05±35.41 µm, ACD was 2.96±0.52 mm, spherical equivalent refraction was –1.16±3.48 D, corneal hysteresis was 10.17±1.82, and CRF was 10.14±1.8 (range: 5.45 to 15.1). Mean CRF and corneal hysteresis were distinct among gender: CRF 10.326 in women and 9.810 in men (<i>P</i>=.0266); corneal hysteresis 10.421 in women and 9.727 in men (<i>P</i>=.0031). A negative correlation was found between both CRF and corneal hysteresis with age (r=–0.1255, <i>P</i>=.0434; and r=–0.2445, <i>P</i>=.0001, respectively). No association was found between CRF and average central K (r=0.0633, <i>P</i>=.3086), ACD (r=–0.0474, <i>P</i>=.4498), or spherical equivalent refraction (r=0.1028, <i>P</i>=.1061). Corneal hysteresis was not associated with age and average central K (r=0.0572, <i>P</i>=.3573), ACD (r=0.0060, <i>P</i>=.9236), or spherical equivalent refraction (r=0.0975, <i>P</i>=.1253). Corneal resistance factor and corneal hysteresis were positively associated with CCT (r=0.5760, <i>P</i>=0; and r=0.4655, <i>P</i>=0, respectively).</p>
<h4>CONCLUSIONS</h4><p>Corneal biomechanical metrics of healthy Brazilian patients were associated with CCT, gender, and age. Corneal steepness, ACD, and spherical equivalent refraction did not affect corneal hysteresis and CRF values in the studied population. [<cite>J Refract Surg</cite>. 2008;24:941-945.]</p>
<h4>AUTHORS</h4>
<p>From Federal University of Sao Paulo (Fontes, Nosé); Fluminense Federal University, Rio de Janeiro (Ambrósio, Alonso, Velarde); and Renato Ambrósio Eye Institute, Rio de Janeiro (Ambrósio, Alonso, Jardim), Brazil.</p>
<p>The authors have no proprietary interest in the materials presented herein. Dr Ambrósio is a consultant for Oculus and Reichert.</p>
<p>Correspondence: Bruno M. Fontes, MD, Av das Acacias 150 bl 2 apto 1001, Barra da Tijuca, Rio de Janeiro – RJ, 22776-000, Brazil. Tel/Fax: 21 3151 3599; E-mail: <a href="mailto:brunomfontes@terra.com.br">brunomfontes@terra.com.br</a></p>
<p>Received: March 15, 2007</p>
<p>Accepted: September 19, 2007</p>
<p><b>Posted online: April 30, 2008</b></p>