Scanning beyond the limits of standard OCT with a Fourier domain optical coherence tomography integrated into a slit...

With a new Fourier domain optical coherence tomography (FD OCT) device, SL SCAN-1 (Topcon Europe Medical BV, Capelle a/d IJssel, The Netherlands), integrated into a slit-lamp OCT, scans can be obtained through a handheld lens. The necessary adjustment of the reference arm is possible by fast Z-alignment. This study was performed to prove the capability of SL SCAN-1 to scan through a three-mirror contact lens, scanning the peripheral retina and anterior chamber angle.

Different representative pathologies of the peripheral retina and anterior chamber were simultaneously observed and scanned with the SL SCAN-1. The scans of peripheral retinal lesions were obtained both through a handheld lens and through a three-mirror contact lens. The anterior chamber angle was scanned directly with the SL SCAN-1 in anterior mode, and through the gonio-mirror of a three-mirror contact lens with the SL SCAN-1 in posterior mode.

OCT scans could be obtained with the SL SCAN-1 of the peripheral retina through both, a common handheld lens and a three-mirror contact lens. The scans obtained through a three-mirror contact lens were of better quality, visualizing details of the different layers of the retina more clearly. The scans of the anterior chamber, obtained through the gonio-mirror of a three-mirror contact lens, visualized the open anterior chamber angle, with details of fine structures.

The SL SCAN-1 is a unique FD OCT system, which is able to scan not only the posterior pole and anterior segment but also the anterior chamber angle and the more peripheral retina. These four modalities combined into one device could make the SL SCAN-1 a very powerful aid in daily practice.