Anterior Ocular Biometrics Using Placido-scanning-slit System, Rotating Scheimpflug Tomography, and Swept-source Optical Coherence Tomography

Abstract

Purpose: To compare anterior biometry measurements using placido-scanning-slit topography, rotating Scheimpflug tomography, and swept-source optical coherence tomography.Methods: A retrospective review consisted of 80 eyes of 49 participants who underwent anterior chamber depth (ACD), central corneal thickness (CCT), and keratometry examination on the same day. We used placido-scanning-slit topography (ORBscan II), rotating Scheimpflug tomography (Pentacam HR), and swept-source optical coherence tomography (CASIA SS1000). The intraclass correlation coefficients and Bland-Altman plots were used to evaluate the agreement and differences between measurements.Results: The mean ACD values were 2.88 ± 0.43, 2.82 ± 0.50, and 2.68 ± 0.44 mm; and the mean CCT values were 536.96 ± 31.19, 543.79 ± 31.04, and 561.41 ± 32.60 μm; and the mean keratometry (Km) were 43.81 ± 1.69, 43.81 ± 1.77, and 44.65 ± 1.95 diopters; as measured by CASIA SS-1000, Pentacam HR, and ORBscan II, respectively. Among the three devices, ACD was deepest to shallowest in the order of CASIA SS-1000, Pentacam HR, and ORBscan II (p < 0.05). The CCT was thickest to thinnest in the order of ORBscan II, Pentacam HR, and CASIA SS-1000 (p < 0.05). No significant differences in Km values were examined between CASIA SS-1000 and Pentacam HR, whereas ORBscan II overestimated Km with a statistically significant difference compared to the other two devices.Conclusions: High level of agreement was found between CASIA SS-1000 and Pentacam HR for anterior parameters, including ACD, CCT, and Km, suggesting interchangeability. However, ORBscan II measurements differed considerably with the measurements obtained from the other two devices; therefore, it should not be used interchangeably. However, further studies with repeatability test should be considered in order to elucidate the reliability of each device.

Comparison of keratometric values and anterior segment parameters measured using Scheimpflug Sirius topography and Lenstar biometry

“…In cataract and refractive surgery, precise measurement of anterior segment parameters and accurate estimation of the refractive index are essential for satisfactory postoperative visual acuity. Furthermore, accurate evaluation of anterior segment parameters is crucial for understanding the pathophysiology of various diseases, including corneal diseases, primary open-angle or closed-angle glaucoma, and pigmentary glaucoma, and the success of surgery [10].…”

Risk Factors for Pupillary Optic Capture Following Sutureless Flanged Intraocular Lens Fixation for Intraocular Lens Dislocation

“…Postoperative anterior chamber depth (ACD), defined as the distance from the corneal endothelium to the anterior surface of the IOL, was measured with a rotating Scheimpflug camera (Pentacam, Oculus Optikgerӓte GmbH, Wetzlar, Germany), as described previously. 11…”

Changes in anterior chamber biometry and intraocular pressure after uneventful phacoemulsification in non-glaucomatous eyes

“…Clinical assessment of the anterior segment is usually achieved using slit-lamp biomicroscopy [ 16 ]; however, objective assessment of the angle is limited, and direct anterior chamber angle examination can also be achieved using diagnostic contact lenses such as the Goldmann 3-mirror lens [ 17 ]. Recently, numerous tools for anterior segment evaluation have been invented, such as ultrasonic biomicroscopy [ 18 ], optic coherence tomography [ 19 , 20 ], Orbscan slit topography [ 20 ], and Pentacam Scheimpflug imaging [ 19 , 20 ]. Each of these tools provides quantitative assessment and qualitative imaging of the anterior segment structures.…”