RESUMO
To assess and compare the degree of agreement of anterior chamber depth [ACD] and axial length [AL] measurements by optical devices [Orbscan II] and contact ultrasound A-scan. In this prospective study of 30 eyes of 25 consecutive patients, ACD and AL estimation were done by 2 methods-scanning slit topography [Orbscan II] and contact ultrasound A-scan. One observer performed all Orbscan measurements and another performed all the ultrasonic measurements. Repeated measures Analysis of Variance [ANOVA] was used to analyze difference between ACD and AL measurements by the 2 methods. Difference in measurements between methods was assessed using the paired t test. The mean ACD [SD] by the 2 methods was 3.658 mm [0.254], and 3.406 mm [0.348], respectively. There was a statistically significant difference between measurements recorded by the 2 methods [P>.01]. Mean contact A-scan measurements were 0.252 mm lower than by Orbscan II. The mean AL were 24.220 mm [0.851] and 23.897 [0.857] mm respectively. There was none statistically significant difference between measurements recorded by the 2 methods [P>.01]. Mean contact A-scan measurements were 0.323 mm lower than by Orbscan II. Applanation ultrasound gives consistently lower measurements for ACD as well as the AL compared to Orbscan II