Anatomical manifestations of primary blast ocular trauma observed in a postmortem porcine model.
OBJECTIVE
We qualitatively describe the anatomic features of primary blast ocular injury observed using a postmortem porcine eye model. Porcine eyes were exposed to various levels of blast energy to determine the optimal conditions for future testing.


METHODS
We studied 53 enucleated porcine eyes: 13 controls and 40 exposed to a range of primary blast energy levels. Eyes were preassessed with B-scan and ultrasound biomicroscopy (UBM) ultrasonography, photographed, mounted in gelatin within acrylic orbits, and monitored with high-speed videography during blast-tube impulse exposure. Postimpact photography, ultrasonography, and histopathology were performed, and ocular damage was assessed.


RESULTS
Evidence for primary blast injury was obtained. While some of the same damage was observed in the control eyes, the incidence and severity of this damage in exposed eyes increased with impulse and peak pressure, suggesting that primary blast exacerbated these injuries. Common findings included angle recession, internal scleral delamination, cyclodialysis, peripheral chorioretinal detachments, and radial peripapillary retinal detachments. No full-thickness openings of the eyewall were observed in any of the eyes tested. Scleral damage demonstrated the strongest associative tendency for increasing likelihood of injury with increased overpressure.


CONCLUSIONS
These data provide evidence that primary blast alone (in the absence of particle impact) can produce clinically relevant ocular damage in a postmortem model. The blast parameters derived from this study are being used currently in an in vivo model. We also propose a new Cumulative Injury Score indicating the clinical relevance of observed injuries.
Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas.
Daniel
D
Sherwood
William E
WE
Sponsel
Brian J
BJ
Lund
Walt
W
Gray
Richard
R
Watson
Sylvia L
SL
Groth
Kimberly
K
Thoe
Randolph D
RD
Glickman
Matthew A
MA
Reilly
D000818:Animals; D000869:Anterior Eye Segment / Q000473:pathology*; D001753:Blast Injuries / Q000000981:diagnostic imaging / Q000473:pathology*; D004195:Disease Models, Animal; D005131:Eye Injuries / Q000000981:diagnostic imaging / Q000473:pathology*; D033401:Microscopy, Acoustic; D010781:Photography; D015422:Scleral Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D013552:Swine; D015599:Trauma Severity Indices; D014741:Video Recording; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging / Q000473:pathology*
blast impact; histopathology; primary blast injury; trauma; ultrabiomicroscopy (UBM)