title: Optimization of the open-loop liquid crystal adaptive optics retinal imaging system.
abstract: An open-loop adaptive optics (AO) system for retinal imaging was constructed using a liquid crystal spatial light modulator (LC-SLM) as the wavefront compensator. Due to the dispersion of the LC-SLM, there was only one illumination source for both aberration detection and retinal imaging in this system. To increase the field of view (FOV) for retinal imaging, a modified mechanical shutter was integrated into the illumination channel to control the size of the illumination spot on the fundus. The AO loop was operated in a pulsing mode, and the fundus was illuminated twice by two laser impulses in a single AO correction loop. As a result, the FOV for retinal imaging was increased to 1.7-deg without compromising the aberration detection accuracy. The correction precision of the open-loop AO system was evaluated in a closed-loop configuration; the residual error is approximately 0.0909λ (root-mean-square, RMS), and the Strehl ratio ranges to 0.7217. Two subjects with differing rates of myopia (-3D and -5D) were tested. High-resolution images of capillaries and photoreceptors were obtained.
authors.affiliation: State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Changchun, Jilin 130033, China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Kong
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Mingliang
authors.initials: M
authors.lastname: Xia
authors.forename: Dayu
authors.initials: D
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Qi
authors.forename: Li
authors.initials: L
authors.lastname: Xuan
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D050866:Liquid Crystals / Q000737:chemistry*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology*; D042261:Retinoscopes; D012680:Sensitivity and Specificity