Modeling Study Incorporating Depth-Dependent Transverse Reinforcement due to Variation in Collagen Lamellae Interweaving in Corneal Tissue

The cornea is crucial for maintaining refraction and focusing ability of the eye. Small alterations in mechanical behavior of the tissue can cause changes in curvature and structure of the cornea, having adverse affects on visual acuity. Since the corneal stroma makes up 90% of corneal thickness and contains a majority of the tissue’s collagen content, it is considered the dominant contributor to the tissue’s mechanical strength and stiffness, which originates from a complex fiber-reinforced structure [1]. It has been shown that collagen lamellae (comprised of type I collagen fibrils) within a dense, proteoglycan-rich matrix, are highly interwoven in the anterior third of the cornea and the degree of interweaving decreases significantly through the thickness with relatively no interweaving observed in the posterior third [1]. The interwoven structure also varies within the plane of the tissue, gradually increasing from a planar arrangement in the central cornea to a highly interwoven arrangement near the limbus [2].