Establishment of Personalized Finite Element Model of Crystalline Lens Based on Sweep-Source Optical Coherence Tomography

Abstract

The virtual lens model has important value in ophthalmic research, clinical diagnosis, and treatment. However, the establishment of personalized lens models and the verification of accommodation accuracy have not been paid much attention. We proposed a personalized lens model establishment and the accommodation accuracy evaluation method based on sweep-source optical coherence tomography (SS-OCT). Firstly, SS-OCT is used to obtain a single lens image in the maximum accommodation state. After refraction correction, boundary detection, and curve fitting, the central curvature radius, thickness, and lens nucleus contour of the anterior and posterior surfaces of the lens were obtained. Secondly, a personalized finite element model improved from Burd’s model was established using these individual parameters, and the adaptation process of the lens model was simulated by pulling the suspensory ligament. Finally, the shape and refractive power changes of the real human lens under different accommodation stimuli were collected and compared with the accommodation process of the finite element model. The results show that the accommodation process of the finite element model is highly consistent with that of the real lens. From the un-accommodation state to the maximum-accommodation state, the difference rate of all geometric and refractive parameters between the two is less than 5%. Thus, the personalized lens finite element model obtained by the calibration and correction of the existing model can accurately simulate the regulation process of a specific human lens. This work helps to provide a valuable theoretical basis and research ideas for the study of clinical diagnosis and treatment of related diseases.

Controversial Issues of the Mechanism of Crystalline Lens Accommodation and the Rationale the Hydraulic Component in its Implementation

“…1). This was confirmed by magnetic resonance imaging, ultrasound scanning and optical coherence topography data [7][8][9][10][11][12].…”

“…During accommodation, the profile of the anterior surface of crystalline lens became steeper and the depth of the anterior chamber decreased. In this case, only minor changes in the profile of the posterior surface of crystalline lens, the depth of the vitreous chamber and the axial length of the eye were noted [7][8][9][10][11][12].…”

“…2). As already noted, the directed flow of intraocular fluid from the anterior to the posterior cortical layers, then into the retrolental space and the vitreous body has been proven by experimental studies of a number of authors [12][13][14][15][16]. It should be noted that the lenticomacular canal begins from the retrolental space, limited by the Viger's capsular-vitreal ligament.…”