Intraoperative OCT vs Scheimpflug and swept-source OCT measurements for anterior eye parameters.

Abstract

To compare agreement of anterior segment parameter measurements using an intraoperative optical coherence tomography (iOCT) of a femtosecond laser (LenSx) during interface docking to the eye with preoperative Scheimpflug tomography (Pentacam AXL) and swept-source optical coherence tomography (SS-OCT) (IOLMaster 700). Department of Ophthalmology, Goethe University, Frankfurt, Germany. Retrospective study. Anterior segment measurements were performed in mydriasis prior to surgery using Scheimpflug tomography and SS-OCT. Postoperatively, iOCT images were analyzed using a modification of the FIJI image-processing program. Outcome measures included external anterior chamber depth (ACD), central corneal thickness (CCT), and central lens thickness (LT). 95 eyes of 66 patients who underwent planned OCT guided femtosecond laser-assisted lens surgery were included. The ACD measured with the iOCT was -0.011 ± 0.126 mm smaller (P = .389) than that with the SS-OCT and -0.059 ± 0.185 mm than with the Scheimpflug tomography (P = .003). The SS-OCT measured a -0.047 ± 0.146 mm smaller ACD than the Scheimpflug tomography (P = .002). The measurements of CCT using the iOCT and the Scheimpflug tomography (-0.705 ± 20.837 μm, P = .742) and the LT measurements using SS-OCT and iOCT (-0.050 ± 0.089 mm, P < .001) showed no clinically relevant difference. Only the ACD between the iOCT and the Scheimpflug tomography showed a clinically relevant difference. The comparison of the anterior segment parameters of iOCT with SS-OCT showed no clinically relevant differences regarding the ACD and the LT. However, Scheimpflug tomography vs iOCT measured a small clinically relevant difference for ACD. The iOCT showed no clinically relevant differences in anterior segment parameters compared with the SS-OCT. A small clinically relevant difference for ACD was found in comparison with that of a Scheimpflug device.