眼轴及眼前节SS-OCT一体化成像系统

Abstract

A system of Swept-Source Optical Coherence Tomography for synchronous measurement of the eye axis with large imaging depth range and anterior segments was proposed to solve the problem that traditional ophthalmic axis measuring instruments can not achieve the functions of large imaging depth in axial measurement and imaging on anterior simultaneously. The proposed system increased the imaging depth by designing a infrared swept source with wide range. Then a calibrated optical path was built for k-domain resampling to improve the imaging quality in large range interference. Thus the high precision axial information and the anterior segment image could be obtained simultaneously. To solve the problem of low SNR of OCT images in this system, an edge-preserving denoising algorithm based on anisotropy filtering was proposed to suppress the speckle noise, which effectively improved the image contrast. Using the equal-proportion human eye model and vitro fish eye imaging respectively, the experimental result shows that the imaging depth of the system can reach 69 mm. The 12 mm anterior segment can be completely scanned in transverse direction, while the axial five-layer structure is accurately measured. The average measurement error of axial length is 0.04 mm, and the imaging time is about 0.45 s, which fulfil the real-time requirements of clinical medical application.