Handheld optical coherence tomography angiography.

Jianlong Yang,David Huang,Liang Liu,J Peter Campbell,Gangjun Liu

doi:10.1364/boe.8.002287

Jianlong Yang, David Huang + Show 3 more

Open Access

https://doi.org/10.1364/boe.8.002287

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Abstract

We developed a handheld optical coherence tomography angiography (OCTA) system using a 100-kHz swept-source laser. The handheld probe weighs 0.4 kg and measures 20.6 × 12.8 × 4.6 cm3. The system has dedicated features for handheld operation. The probe is equipped with a mini iris camera for easy alignment. Real-time display of the en face OCT and cross-sectional OCT images in the system allows accurately locating the imaging target. Fast automatic focusing was achieved by an electrically tunable lens controlled by a golden-section search algorithm. An extended axial imaging range of 6 mm allows easy alignment. A registration algorithm using cross-correlation to register adjacent OCT B-frames with propagation from the central frame was used to effectively minimize motion artifacts in volumetric OCTA images captured in relatively short durations of 1 and 2.1 seconds. 2.5 × 2.5 mm (200 × 200 pixels) and 3.5 × 3.5 mm (300 × 300 pixels) retinal angiograms were demonstrated on two awake adult human subjects without the use of any mydriatic eye drops.

Highlights

Optical coherence tomography (OCT) is a noninvasive imaging technique that can achieve in vivo high-resolution cross-sectional images of the human eye and has been widely used in the diagnosis and treatment of various diseases in ophthalmology such as glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD) [1,2,3]
A series of research works on the development of handheld scanning laser ophthalmoscopy (SLO) and OCT probe have demonstrated by researchers at Duke University [16,17]
We developed a handheld OCT system with features optimized for optical coherence tomography angiography (OCTA) applications, which include a golden search based fast automatic focusing subsystem, an extended axial imaging range, fast scanning protocols and a simple registration algorithm

Summary

Introduction

Optical coherence tomography (OCT) is a noninvasive imaging technique that can achieve in vivo high-resolution cross-sectional images of the human eye and has been widely used in the diagnosis and treatment of various diseases in ophthalmology such as glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD) [1,2,3]. Most of the commercial and research OCT systems for ophthalmology are in a fixmounted table-top form, which requires the research subjects or patients sit in front of the machine and hold their eye open for several seconds to finish the imaging process This is difficult for people with certain types of disabilities and young children. A series of research works on the development of handheld scanning laser ophthalmoscopy (SLO) and OCT probe have demonstrated by researchers at Duke University [16,17] Most recently, they observed the retinal photoreceptor cells of young children based on their welldeveloped handheld probe and SLO imaging technique [18]. All of these requirements make the successful acquisition of OCTA from a handheld device very challenging

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