Comparison of anterior segment measurements using rotating Scheimpflug imaging and partial coherence interferometry

AIM:To compare central corneal thickness(CCT) and anterior chamber depth(ACD) measurements using rotating Scheimpflug imaging and partial coherence interferometry.·METHODS:As part of the first phase of Shahroud Eye Cohort Study with 5 190 subjects of 40 to 64 years of age,CCT and ACD were measured using Scheimpflug imaging with the Pentacam(Oculus,Inc.,Lynnwood,WA,USA) and partial coherence interferometry with the Allegro BioGraph(Wavelight,Erlangen,Germany).·RESULTS:After applying exclusion criteria,we had data of 4 387 subjects with a mean age of 50.7±6.2 years.Mean CCT with Pentacam and BioGraph were 528.6 ±33.2μm and 525.6 ±32μm respectively;the difference was statistically significant(P <0.001),but the correlation was high(R=0.920).Mean ACD measurements using Pentacam and BioGraph were 2.68 ±0.35mm and 2.62 ±0.33mm respectively;the inter-device difference was significant(P <0.001) with high correlation(R=0.944).The 95% limits of agreements between devices were-22.65μm to28.61μm and-0.16mm to 0.29mm for CCT and ACD measurements,respectively.·CONCLUSION:For both CCT and ACD,the BioGraph gave significantly lower values than the Pentacam(P <0.05).Despite the high inter-device correlation,the 95%limits of agreements were wide,and this may limit their interchangeability in measuring the CCT and ACD.