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 to 28.61µm 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.