Imaging of Glaucoma Implant Tubes in the Ciliary Sulcus With Ultrasound Biomicroscopy (UBM) and Slit-Lamp Adapted Optical Coherence Tomography (SL-OCT)

Abstract

Purpose:: To evaluate the ability of UBM and SL-OCT to image the entry site and glaucoma tube position following insertion through the ciliary sulcus.

Methods:: 7 eyes (7 patients) were enrolled. Serial cross sectional UBM and SL-OCT were obtained by a single examiner (SD). Images were interpreted by a single investigator (CT) who was masked to the patient data. Images were assessed for entrance and position of the glaucoma implant tube within the ciliary sulcus.

Results:: Mean patient age was 62.0 ± 16.6 (SD) years. All tubes were inserted in the superotemporal quadrant through the ciliary sulcus. Six of 7 patients had primary open-angle glaucoma and one had chronic angle-closure glaucoma. Four patients had history of penetrating keratoplasty. Both modalities imaged the tube position on the surface of the sclera. UBM was able to identify and image the tube within the ciliary sulcus and posterior to the iris. SL-OCT could not image the tube within the posterior chamber in any eye.

Conclusions:: UBM and SL-OCT are capable of imaging glaucoma implant tubes external to the sclera. When information regarding tube position or obstruction behind the iris plane in needed, ultrasound biomicroscopy is required. SL-OCT is currently not capable of imaging ocular structures behind the iris plane.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: clinical • image processing