[Reliability of corneal thickness measurements by Orbscan II and ultrasound pachymeter].

PURPOSE To access the reliability of corneal thickness measurements by Orbscan II and ultrasound pachymeter. METHODS A retrospective study of 134 eyes from 67 normal subjects between January and June 2001 was obtained. Sex, age, visual acuity, refractive error and corneal thickness measurements by Orbscan II and ultrasound pachymetry were evaluated. All results were analyzed by the paired t test (p<0.05). RESULTS Sixty-seven subjects, 34 (50.7%) female and 33 (49.3%) male, with a mean age of 32.44+/-9.98 were evaluated. The mean of spherical equivalent was -2.68+/-2.62. The mean corneal thickness was 534.81+/-34.45 with the Orbscan II system and 535.00+/-29.53 with the ultrasound pachymeter, values that were not significantly different (p=0.8922). The correlation coefficient between both instruments was 0.8774, and it is effective. CONCLUSIONS Both methods are similar showing good correlation. In this study, the Orbscan II showed reliability, and this tool is extremely useful to evaluate subjects regarding refractive surgery.