Handheld OCT Angiography Probe for Imaging of Infants in the Clinic or Nursery

Abstract

Purpose : This work describes the development of an ergonomic, portable handheld optical coherence tomography angiography (HH-OCTA) probe and the first HH-OCTA images acquired on non-sedated infants. Since most OCTA systems are large table systems that cannot be easily used to image non-compliant subjects such as infants, HH-OCTA allows for the extension of OCTA into the nursery and can provide valuable diagnostic information.

Methods : In order to minimize the effect of operator hand motion on HH-OCTA images, we designed an ergonomic HH-OCTA probe that is optimized to be held by its tip, the grip our imagers were using with other HH-OCT systems. The HH-OCTA probe weighed 700g, used a 200 kHz swept source OCT engine, has ±10D refractive error correction, and a 30x30° degree field of view. All human subjects research was performed under protocols approved by the Duke University institutional review board in accordance with the Declaration of Helsinki. HH-OCTA images were taken over an approximately 4x4 mm field of view in non-sedated infants in the clinic and in the intensive care nursery (ICN). OCTA images were acquired with 500 A-scans/B-scan, 500 lateral locations sampled, with 4 repeat scans at each B-scan location. OCTA images were generated in post processing using speckle variance and graph search based segmentation was used to create projections of the vasculature.

Results : HH-OCTA imaging was performed in 10 un-sedated infants in the clinic and ICN. Fig. 1 shows the handheld probe as well as OCTA images from a 41 week post menstrual age infant with a history of retinopathy of prematurity. Near the fovea OCTA reveals small bulb-like vascular terminations that could be small vascular loops or micro-aneurysms.

Conclusions : We demonstrated an optically novel, ergonomic, 200 kHz HH-OCTA probe optimized for supine non-contact imaging. To the best of knowledge these are the first HH-OCTA images taken of non-sedated infants.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Left: Image of the handheld OCTA probe being used to image an infant in the ICN and a representative 30° B-scan. Right: OCTA from a 41 week PMA infant showing vascular loops near the fovea (red star) and selected B-scan with OCTA flow overlaid in color. The yellow line on OCTA denotes the location of the selected B-scan. The green line on the B-scan denotes the location of the IPL.