Three-Dimensional Computational Model of Mechanics of Human Ocular Accommodation

Tuesday, April 21, 2015: 2:00 PM
Room 3 (San Diego Convention Center)
AnnMarie Hipsley, PhD
Daniel B. Goldberg, MD
Silvia S. Blemker, PhD

Purpose
To develop a 3D finite element computational model of the normal functioning accommodation mechanism in the eye which includes the lens, the zonular fibers, the ciliary body/muscle, and the sclera in order to illuminate the mechanical function of accommodation, specifically the function of the ciliary muscle.

Methods
A literature review of data on accommodation function are used to define the geometry and material properties of the anatomical structures. Available biometry and imaging data is incorporated.  3D Computational modeling and Finite Element Analysis (FEA) of the mechanism of accommodation was developed. Model predictions of lens accommodation were compared with the literature and clinical knowledge. Analysis of ciliary muscle specific effects on the accommodation mechanism are demonstrated.

Results
The 3D Computational model was able to demonstrate the strain forces of the ciliary muscle during accommodation and disaccommodation in our lab. We were able to demonstrate force vectors toward the lens both agonistic and antagonistic. The model was validated with published experimental measurements and demonstrated statistically significant utility for predicting lens accommodation as a result of ciliary body contraction.

Conclusion
Integration of accommodation mechanisms imaging and computer models may prove a valuable tool to reveal structure-function relationships and improve presbyopia surgery outcomes. New insights are needed to improve technology and surgeries of both emmetropic presbyopia and cataract surgery that also has a presbyopic application such as accommodating IOLs.