Contact Handheld Ultra-high Speed and Ultra-widefield OCT

Abstract

Purpose : We develop an ultra-widefield handheld swept-source OCT (SS-OCT) imaging system with an 800-kHz VCSEL light source that achieved an unprecedented 140° FOV for clinical imaging of pediatric peripheral retina.

Methods : We utilized a 1060 nm center wavelength, 800-kHz A-scan sweep rate VCSEL (Thorlabs, Inc.) swept-source laser with 100 nm bandwidth that provides an imaging depth of 6 mm and an axial resolution of 4.94 µm in air. The incident power on the cornea was 1.75 mW. The contact ocular lens (Volk Optical Inc.) was composed of an advanced aspheric lens and a meniscus lens. The curvature of the meniscus lens was specifically designed for pediatric patients with small eyes to minimize the patient’s discomfort while maintaining stability. The scanning protocol consisted of 800 A-scans/B-scan and 780 B-scans/Volume (0.78 second for each volume). OCT images were acquired and processed by our GPU accelerated software and displayed on the imaging probe, allowing direct real-time feedback to facilitate alignment process and navigation.

Results : Twenty-seven pediatric patients were recruited. Each imaging session, including an alignment process and data acquisition, was completed within 2 minutes. Two representative en face OCT images with posterior pole and peripheral retina in a single shot obtained via contact approach from two pediatric patients with and retinoblastoma and retinopathy of prematurity (ROP) were shown in Figure 1. The detailed morphologies of retinal periphery were fully appreciated in these images without pronounced motion artifacts.

Conclusions : We presented a contact 800-kHz handheld OCT imaging system with an unprecedented single shot of 140° FOV that extended the imaging area from the posterior pole to retinal periphery. The detailed morphologies and adequate visualization of the peripheral retina are valuable in assessing and diagnosing pathologies starting from the retinal periphery.

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