Eli Pavlatos Places 3rd in PhD Student Presentation

Eli Pavlatos, a current PhD student in Biomedical Engineering, recently placed third in the PhD Student Podium Presentation Competition in the area of “Tissue Mechanics – Characterization”, at the 2015 Summer Biomechanics, Bioengineering, and Biotransport Conference (SB3C) in Snowbird, Utah.

Eli's presentation was titled: "3D Strains in Posterior Sclera Using Ultrasound Speckle Tracking".

Abstract: Glaucoma is an ocular pathology associated with vision loss via damage to the optic nerve, which is responsible for transmitting visual signals to the brain. It is known that such damage initiates at the optic nerve head (ONH), where the nerve axons exit the eye through the scleral canal. Intraocular pressure (IOP) induced strains and stresses in the ONH and peripapillary sclera may play a role in the progression of optic nerve damage. In this study, strains were measured in the peripapillary sclera of nine human donor globes. The ocular shells were mounted using a custom-built pressurization chamber and an inflation test was performed with four pressure steps: 11.5, 13, 15, and 19 mmHg. Ultrasound radiofrequency data was acquired at each pressure step to build a 3D volume of the peripapillary sclera centered at the ONH. The principal and maximum shear strains were calculated using a MATLAB ultrasound speckle tracking algorithm. The 1st and 3rd principal strains indicated that the peripapillary sclera experiences through-thickness compression and meridional tension during inflation. The 2nd principal strain showed that little deformation occurs in the circumferential direction around the ONH, consistent with the known preferred arrangement of collagen. The maximum shear was larger than all three principal strains and oriented at a 45 degree angle between the 1st and 3rd principal strain vectors. Significant amounts of shear strain during physiological increases in IOP may be implicated in glaucoma risk and could potentially play a role in the ONH torsion and bending that is commonly observed in patients with normal tension glaucoma.

Co-authors of the presentation included his advisor, Dr. Jun Liu, Richard T. Hart and Hugh J. Morris of Ohio State; Benjamin Cruz-Perez of Accenture in Sacramento, California; and Hong Chen of Vasomedical, Inc. in the Greater New York City Area.

Congratulations Eli!