Abstract
Purpose:
The purpose of this study was to assess if ultrasound biomicroscopy (UBM) is a viable imaging tool to characterize suprachoroidal injections.
Methods:
Four enucleated human globes (Georgia Eye Bank, Atlanta GA) from two donors were received within 6 hours from time of death. Each globe received 4, 50µl injections of 40 mg/mL triamcinolone acetonide suspension (Clearside Biomedical Inc., Alpharetta GA). Suprachoroidal injections were performed with a microneedle (Clearside Biomedical Inc., Alpharetta GA) at 6-8 mm posterior to the limbus within each quadrant of the globe. Images of the injection sites were taken pre and post-injection using a UBM probe (UBM Plus, Accutome, Malvern,PA). Images were compared to determine if there was an expansion of the layers of the eye (conjunctiva, sclera, choroid, and retina).
Results:
The UBM imaging demonstrated a clear distinction between pre- and post-images. Conjunctival thickness ranged from 0.130 - 0.320 mm. Scleral thicknesses ranged from 0.6-1.2 mm pre-injection and increased on average by 0.3 mm post-injection. Post-injection images revealed a hypoechoic region with low ultrasound reflectivity in the lower half of the sclera closest to the choroid. The combination of scleral thickness increase and the presence of the hypoechoic region was evidence of the suprachoroidal injection. Suprachoroidal injections were confirmed at all sites.
Conclusions:
Suprachoroidal delivery can be confirmed using UBM through visualization of the suprachoroidal space and expansion of the sclera.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
708 sclera •
419 anatomy