High-rate internal pressurization of human eyes to predict globe rupture

Abstract

Objective: To determine the dynamic rupture pressure of the human eye by using an in vitro high-rate pressurization system to investigate blunt-impact eye injuries.

Methods: Internal pressure was dynamically induced in the eye by means of a drop-tower pressurization system. The internal eye pressure was measured with a small pressure sensor inserted into the eye through the optic nerve. A total of 20 human eye tests were performed to determine rupture pressure and characterize rupture patterns.

Results: The high-rate pressurization resulted in a mean (SD) rupture pressure of 0.97 (0.29) MPa (7275.60 [2175.18] mm Hg). A total of 16 eyes ruptured in the equatorial direction, whereas 4 ruptured in the meridional direction. There was no significant difference in the rupture pressure between the equatorial and meridional directions (P= .16).

Conclusion: As the loading rate increases, the rupture pressure of the human eye increases.

Clinical relevance: Eye injuries are expensive to treat, given that the estimated annual cost associated with adult vision problems in the United States is $51.4 billion. Determining globe rupture properties will establish injury criteria for the human eye to prevent these common yet devastating injuries.