The Effects of Orbital Muscles on Eye Injury

1. The Effects of Orbital Muscles on Eye Injury BiomechanicsStefan Duma, Virginia Polytechnic Institute and State University (Virginia Tech)Page 1 of 2 Eye injuries affect a large portion of the population, frequently result in long-term disability, and are very expensive to treat. Each year, approximately 2.4 million individuals sustain an eye injury. Current morbidity statistics reveal that at least 30,000 such victims are left blind in at least one eye. Major eye injuries occur in motor vehicle crashes, as a consequence of sports-related impacts, and during military operations. This project is examining the effects of the superior and inferior oblique eye muscles relative to eye injury biomechanics. The research effort is attempting to determine whether the oblique muscles contribute to the most severe open globe ruptures. This is significant given that all previous eye rupture injury research has used in vitro cadaveric human and animal eyes that did not have intact oblique muscles. The research hypothesis is that when an eye is subjected to blunt trauma, forces that are created by the oblique orbital muscles significantly contribute to the risk of the globe rupturing. If the hypothesis is validated, all previous research that did not include the oblique muscles will have underestimated forces and mechanisms of globe rupture. (Continued)

2. The Effects of Orbital Muscles on Eye Injury BiomechanicsStefan Duma, Virginia Polytechnic Institute and State University (Virginia Tech)Page 2 of 2 Using in situ cadaveric eyes, the research plan involves quantifying tensile forces exerted on the eye from the superior and inferior oblique muscles; quantifying eye displacements between impact tests with the oblique muscles and matched tests without the oblique muscles; evaluating the viscoelastic, or rate dependent, nature of the forces and displacement as a function of the oblique muscles; and characterizing the effectiveness of existing eye injury criteria developed from previous research performed on specimens without the oblique muscles. The successful completion of this project will result in an improved understanding of eye injury biomechanics that will be used to: develop and design protective measures; evaluate surgical repair techniques; and explain injury mechanisms at the tissue level.