Demonstration of a Novel Ophthalmic 3D Ultrasound Acquisition Device

Abstract

Purpose : The exploration of ophthalmic 3-dimensional (3D) ultrasound (US) on human eyes in vivo has been limited, and its clinical utility has yet to be explored. Though 3D US has been used to image some intraocular structures, there is no device that allows for noninvasive, rapid 3D US reconstruction of ocular structures in the clinical setting. Here we demonstrate a novel approach to adapt any existing ultrasound tool to a slit lamp, actuate the probe across the globe, and reconstruct 3D volumes of ophthalmic structures.

Methods : Our novel ophthalmic 3D US acquisition device utilizes a 10MHz Ellex Eye Cubed™ US probe, which is then mounted onto a slit lamp. The US acquisition device electromechanically moves the ophthalmic US probe across a live subject’s closed eyelid to obtain standardized datasets that can be used to generate 3D models of the optic nerve and retina-choroid-sclera (RCS) complex. Our device was 3D printed and used stepper motors, linear actuators, an arduino uno, a computer numerical control stepper motor hat for arduino, a 12 volt power supply, and a custom 3D printed control box. A custom python program then extracted US image datasets from videos of B-scan US. In each extracted image, the optic nerve and RCS complex were manually segmented using Affinity Photo. The segmented datasets were then imported into 3D Slicer to be constructed and rendered into a 3D model of the eye.

Results : The 3D acquisition device is featured in Figure 1. Our 3D acquisition device successfully gathered data that was used to create a 3D reconstruction of the RCS complex and optic nerve, as depicted in Figure 2.

Conclusions : We demonstrated an instrument to attach any US device to a slit lamp to acquire US image volumes and generate 3D models of the RCS and optic nerve. This can potentially be used clinically to help physicians more fully understand the morphological changes in ocular pathologies than allowed by standard two-dimensional US techniques. Further investigation is needed to demonstrate our device’s utility in evaluating ocular pathology.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Figure 1: Schematic of slit lamp-mounted horizontal actuator and horizontal raster cube volume acquired with the instrument.

 

Figure 2: A) Example segmentation of the RCS complex (red) and optic nerve (blue) in an extracted US image. B) 3D reconstruction of the RCS complex (green) and optic nerve (yellow) from the anterior and posterior C) views.