Objective To evaluate a new noncontact optical biometer (Lenstar) using optical low-coherence reflectometry and to compare the biometric measurements (axial length,AL and anterior chamber depth,ACD) with those obtained from current clinical instrumentation (IOL-Master and ultrasound A-scan).Methods In this prospective clinical study,measurements of AL and ACD obtained from 123 eyes of 78 subjects with the Lenstar were compared with those obtained with the IOL-Master or ultrasound A-scan.The results were evaluated using Bland-Altman analyses.The differences between both methods were assessed using the paired t test,and its correlation was evaluated by Pearson coefficient.Results Lenstar measurements of AL and ACD were similar to the IOL-Master (average difference=-0.003±0.048mm,P =0.517; average difference=-0.044±0.091mm,P =0.573),respectively.Lenstar measurements of AL and ACD were significantly longer than those of A-scan (average difference=0.117±0.195mm,P ＜0.001; average difference=0.080±0.253mm,P ＜0.001),respectively.A Pearson correlation revealed a high correlation for AL and ACD (r ≥0.916 for all,P ＜0.001for all).Bland-Altman plots showed good agreements for AL measurements and ACD between Lenstar and IOL-Master and the level of agreement was not acceptable betweenLenstar and A-scan.Conclusions For the measurement of AL and ACD,there is goodagreement between Lenstar and IOL-Master.Nevertheless,Lenstar and A-scan cannot beused interchangeably.The results,coupled with a unique ability to analyze the ocular structures non-contactly make the Lenstar a promising new instrument for ocular evaluation in research and clinical practice.