Research

Biomechanics of the Eye

The eye is a complex structure and subjected to mechanical loadings from intraocular pressure, cerebrospinal fluid pressure, and extraocular muscles. Understanding the biomechanics of the eye is essential for clarifying the mechanisms of biomechanically related eye diseases such as glaucoma, and thus can help develop better methods for early detection and treatment, and with these to preserve vision.

Below I highlight some of my past and ongoing projects.

Schematic cross-section through a human eye. [Sigal et al. Biomech Model Mechanobiol, 8(2):85-98, 2009]

Lamina cribrosa
hemodynamics & oxygenation

Blood supply and oxygenation in the lamina cribrosa (LC) are essential for maintaining the functioning of retinal ganglion cell axons and vision. Our goal was to leverage novel 3D eye-specific models of the LC vessel network to identify factors with the largest influence on the LC oxygen.(Full Paper)

Role of collagen fiber interweaving
in sclera stiffness

The collagen fibers of the sclera are interwoven, but numerical models do not account for this interweaving or the resulting fiber-fiber interactions. Our goal was to understand the role of collagen fiber interweaving in sclera stiffness using finite element modeling.
(Full Paper)

Biomechanical role of radially aligned scleral collagen fibers

Recent studies have demonstrated a family of collagen fibers in the innermost sclera organized radially from the scleral canal. Our goal was to determine the role of these radial fibers in the sensitivity of optic nerve head biomechanics to acute increases in intraocular pressure.(Full Paper 1) (Full Paper 2)

Are lamina cribrosa defects
good or bad?

Loss of connective tissues in the lamina cribrosa (LC) is regarded as "LC defects", despite scarce actual evidence of their role. Our goal was to examine how so-called LC defects alter intraocular pressure-related mechanical insult to the neural tissues within the LC.
(Full Paper)

Collagen microstructure
of the lamina cribrosa beams

The collagenous beams of the lamina cribrosa (LC) exhibit natural undulations called "crimp". Our goal was to measure collagen fiber crimp characteristics of the LC beams and determine whether beam width is associated with the three measures of collagen crimp: waviness, tortuosity, and amplitude.
(Full Paper)

Effects of cerebrospinal fluid pressure
on optic nerve head biomechanics

The effects of cerebrospinal fluid pressure (CSFP) on the biomechanical environment within the optic nerve head (ONH) remain unclear. Our goal was to model the sensitivity of the ONH biomechanics to acute variations in intraocular pressure (IOP), CSFP, and central retinal artery blood pressure (BP).(Full Paper)