Retinal Capillary Within Inner Nuclear Layer Imaging Research Based-on Adaptive Optics

The morphology of capillary less than 10μm in diameter can early present the endocrine diseases such as diabetes and hypertension disease. However, the ophthalmoscope in clinical diagnosis can only achieve the capillary images whose diameter is more than 15μm because of the eye aberration. By the eye aberration detection and correction in real-time, adaptive optics(AO) technology can be used to achieve the images in diffraction limit with 3μm. As the retina contains 10 translucency layers, the capillary position and the eye character is different in persons, thus the quick capillary position determining becomes a difficult problem. Meanwhile there are still some other problems on capillary images less than 10μm in diameter with AO technology, including the capillary image contrast problem and the small field of view(FOV) for capillary imaging. In this paper, several measures would be taken on a series of optical system innovation design combined with the eye optical properties.A new method of capillary imaging plane determining that was using retinal visual cell layer as a reference position and positioning the plane of capillary imaging; the data of different human eyes capillary layer public position was calculated; using the model eye to simulate the human eye, the relationship between the effective focal length and axial length between people was obtained.An optical system with AO was constructed and the capillary images were achieved.1) A target was used to retina lateral plane determining and the target was about 1D in front of the pupil which met the accuracy and stability of the eye staring. 2) A movable stage driven by the servo motor was used to determine the longitudinal positioning of the capillary layer. 3) The optical system was optimized which contained the source system design and time-sequence design, the depth of focal was calculated and the influence was analyzed.An adaptive optics system was designed and constructed, the capillary images of 17 eyes were achieved and diameter of capillary was less than 10μm. The contract of capillary images was improved to 0.35 with picture processing.To solve the problem of the small FOV problem, a multiple object adaptive optics system(MOAOS) was designed to improve FOV of the capillary imaging. The number of pixels of LC-SLM and arrangement were analyzed. And the Shack-Hartman wavefront sensor(SHWFS) in the multiple object adaptive optics system was designed and the accuracy of the SHWFS was analyzed by two objects experiment.The study will push the retinal capillary imaging in clinical diagnosis in the future.