Material and Method: In this comperative study, siksty-six eyes of 33 healthy individuals having axial length between 21 mm and 26 mm were recruited in this comparative study. Axial length, anterior chamber depth and lens thickness values obtained from 2 instruments were reported and compared. Bland-Altmann analysis was used to demonstrate agreement between instruments and the 95% limits of agreement were calculated.

Results: Fifteen of 33 cases were man and 18 were women. The mean age of the 33 cases was 33.06±9.70 (19-66) years. Mean axial length, anterior chamber depth and lens thickness for optical biometer and ultrasound biometer were 23.69 (1.09) mm; 3.53 (0.40) mm; 3.78 (0.37) mm and 23.64 (1.07) mm; 3.45 (0.43) mm ve 3.91 (0.40) mm respectively. There was a statistically significant importance between the 2 devices for all parameters (p<0.05). There was a perfect correlation between the 2 instruments for axial length, anterior chamber depth and lens thickness ( r=0.987; r=0.885 and r=0.928 respectively).

Discussion: Considering the fact that the Lenstar is an acceptable instruement for biometry and different results in our study obtained with ultrasonic biometer, although there is a perfect correlation, we concluded that ultrasound biometer cannot substitute for the optical biometer. Keywords : Optical biometer, ultrasound biometer, axial length