Motion-free, three-dimensional optical coherence tomography imaging of retinal diseases

Abstract

Purpose : Re-visiting the same location is essential to monitor the progress of diseases and follow up treatments. Optical coherence tomography (OCT) assess the three-dimensional micrometer-scale structure non-invasively. However, strongly suffered by the eye motion. This paper aims at demonstrating motion-free OCT imaging of retinal diseases.

Methods : The custom-made 1.0-µm swept-source OCT system with a scan speed of 100,000 A-line/s is used. The OCT probe beam was scanned along with a modified Lissajous pattern, which is designed for OCTA. The eye motion is estimated by registration of the overlapped regions. Three-dimensional volumes and en face maps of OCT images can be corrected by the estimated motion amounts. The system provides multi-functional images. In addition to OCT and OCTA, pigment and flow (PAF), which contrasts blood flow and the retinal pigment epithelium (RPE) abnormalities, and RPE-melanin images, which contrasts melanin of the RPE and in the sensory retina, are obtained. A hundred twenty-six patients with retinal abnormalities were scanned, and images were surveyed.

Results : Figure 1 shows motion-free 3D volumetric images of a myopic and branch retinal vein occlusion eyes. The motion-free volumetric OCT of myopia (Fig. 1A) visualizes the bent retinal 3D shape and atrophic region (blue arrow). RPE-melanin volumetric image (Fig.1 C) shows that there are two melano-signal spots in the sensory retina (blue arrows).
Figure 2 shows motion-free en face images of a choroidal neovascularization (CNV) subject before (Fig. 2 A, B, C) and after one month (Fig. 2. D, E, F) of intravitreal anti-VEGF injection provided by multi-contrast OCT. Motion-free images make it easy to find the location of change by the injection. Abnormal blood flow signals remain, and RPE abnormalities seem progressed (green arrows).

Conclusions : Lissajous scan OCT provides several motion-free volumetric and en face images of the posterior eye. This method will be suitable to survey the eye disease conditions.

This is a 2020 ARVO Annual Meeting abstract.

 

Fig. 1. OCT volumes of a myopic eye (A) and a subject with branch retinal occlusion (B), RPE-melanin volume (C) shows two spots in the retina.

 

Fig. 2. Motion-free en face multi-functional OCT imaging results of a subject with CNV. (A, D) OCT, (B, E) PAF, (C, F) RPE-melanin images. Before (A, B, C) and after 1 month (D, E, F) of intravitreal anti-VEGF injection.