Mechanistic hypothesis for eye injury in infant shaking

An experimental and computational study
  • S. Cirovic
  • R. M. Bhola
  • D. R. Hose
  • I. C. Howard
  • P. V. Lawford
  • M. A. Parsons
New Technology

Abstract

The terms abusive head injury and shaken baby syndrome are used to describe a unique pattern of nonaccidental traumatic injuries occurring in children that many clinicians and researchers have good reason to believe is caused by violent shaking. Typical injuries include severe brain injury, with intracranial and retinal hemorrhages, but the pathogenesis of injuries is poorly understood. A major paradox in head trauma in infants is that the injuries induced by a shaking event are much more severe than those caused by even very violent single-impact head trauma, despite the relatively low accelerations in shaking.

We have developed a finite element computer model of the eye, orbit, and orbital bone and used it to simulate the effects of single-impact and oscillatory motion inputs. The model was informed by data from semiquantitative in vitro anatomical traction experiments on in situ rabbit eyes. The new results reported here strongly suggest that suction between the eye and its surrounding fat dominates the dynamical stability of the system composed of the eye, its socket, and the components and material supporting the eye. Computer simulations incorporating this functional anatomical relationship show that deceleration of the head generates pressure gradients inside and outside the eye; these could cause damaging shear stresses in structures such as the retina and blood vessels. Simulations also show that oscillating the bone of the orbit causes the eye to move anteriorly and posteriorly with an increasing amplitude, building up the stresses within the eye over time. This is the first time that any biomechanical mechanism has been identified that might explain the disproportionally severe injuries caused by an oscillatory mechanism such as violent shaking of an abused infant. However, further study is required and this conclusion is therefore preliminary and provisional.

Key Words

Eye injury child abuse computational modeling finite element analysis 

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References

  1. 1.
    Jayawant S, Rawlinson A, Gibbon F, et al. Subdural hemorrhages in infants: population based study. BMJ 1998;317:1558–1561.PubMedGoogle Scholar
  2. 2.
    Levin AV. Retinal hemorrhages and child abuse, in Recent Advances in Pediatrics. (David TJ, ed.), Churchill Livingstone, Edinburgh. 2000; pp. 151–219.Google Scholar
  3. 3.
    The Ophthalmology Child Abuse Working Party. Child abuse and the eye. Eye 1999;13:3–10.Google Scholar
  4. 4.
    Adams G, Ainsworth J, Butler L, et al. Update from the Ophthalmology Child Abuse Working Party Royal College Ophthalmologists. Eye 2004;18:795–798.PubMedCrossRefGoogle Scholar
  5. 5.
    Green MA, Lieberman G, Milroy CM, Parsons MA. Ocular and cerebral trauma in non-accidental injury in infancy: underlying mechanisms and implications for pediatric practice. Br J Ophthalmol 1996;80:282–287.PubMedGoogle Scholar
  6. 6.
    Snodgrass GJ. The eye and the brain in non-accidental injury involving young children. Br J Ophthalmol 1996;80:275.PubMedGoogle Scholar
  7. 7.
    Wilkinson WS, Han DP, Rappley MD, Owings CL. Retinal hemorrhage predicts neurologic injury in the shaken baby syndrome. Arch Ophthalmol 1989;107:1472–1474.PubMedGoogle Scholar
  8. 8.
    Morad Y, Kim YM, Armstrong DC, Huyer D, Mian M, Levin AV. Correlation between retinal abnormalities and intracranial abnormalities in the shaken baby syndrome. Am J Ophthalmol 2002;134:354–359.PubMedCrossRefGoogle Scholar
  9. 9.
    Lyle DJ, Stapp JP, Button RR. Ophthalmologic hydrostatic pressure syndrome. Am J Ophthalmol 1957;44:652–657.PubMedGoogle Scholar
  10. 10.
    David DB, Mears T, Quinlan MP. Ocular complications associated with bungee jumping. Br J Ophthalmol 1994;78:234–235.PubMedGoogle Scholar
  11. 11.
    Jain BK, Talbot EM. Bungee jumping and intraocular hemorrhage. Br J Ophthalmol 1994;78:236–237.PubMedGoogle Scholar
  12. 12.
    Chan J. Ophthalmic complications after bungee jumping. Br J Ophthalmol 1994;78:239.PubMedGoogle Scholar
  13. 13.
    Gilliland MG, Folberg, R. Shaken babies—some have no impact injuries. J Forensic Sci 1996;41:114–116.PubMedGoogle Scholar
  14. 14.
    Duhaime AC, Alario AJ, Lewander WJ, et al. Head injury in very young children: mechanisms, injury types, and ophthalmologic findings in 100 hospitalized patients younger than 2 years of age. Pediatrics 1992;90:179–185.PubMedGoogle Scholar
  15. 15.
    Pounder DJ. Shaken adult syndrome. Am J Forensic Med Pathol 1997;18:321–324.PubMedCrossRefGoogle Scholar
  16. 16.
    Robinson DA. A quantitative analysis of extraocular muscle cooperation and squint. Invest Ophthalmol 1975;14:801–825.PubMedGoogle Scholar
  17. 17.
    Bron AJ, Tripathi RC, Tripathi BJ. The bony orbit and paranasal sinuses, in Wolff’s Anatomy of the Eye and the Orbit. Bron AJ, Tripathi RC, Tripathi BJ. 8th ed., Chapman & Hall Medical, London, 1997; pp. 1–29.Google Scholar
  18. 18.
    Power ED, Duma SM, Stitzel JD, et al. Computer modeling of airbag-induced ocular injury in pilots wearing night vision goggles. Aviat Space Environ Med 2002;73:1000–1006.PubMedGoogle Scholar
  19. 19.
    Bertocci GE, Pierce MC, Deemer E, Aguel F, Janosky JE, Vogeley E. Using test dummy experiments to investigate pediatric injury risk in simulated short-distance falls. Arch Pediatr Adolesc Med 2003;157:480–486.PubMedCrossRefGoogle Scholar
  20. 20.
    Goldsmith W, Plunkett J. A biomechanical analysis of the causes of traumatic brain injury in infants and children. Am J Forensic Med Pathol 2004;25:89–100.PubMedCrossRefGoogle Scholar
  21. 21.
    Welsh TJ, Gilman M. (1969), Voluntary propulsion of the eyes. Am J Ophthalmol 1969;67:583–585.Google Scholar
  22. 22.
    Duke-Elder S, Wybar K. The mechanics of the movement of the eyes. in System of Ophthalmology Vol VI Ocular Motility and Strabismus (Duke-Elder S. ed.), Henry Kimpton, London, 1973; pp. 136–144.Google Scholar
  23. 23.
    Patton N. Self-inflicted eye injuries: a review. Eye 2004;18:867–872.PubMedCrossRefGoogle Scholar
  24. 24.
    Goldsmith W. Biomechanics of head injury. in Biomechanics:its foundations and objectives (Fung YC, Perrone N, and Anliker M, eds), Prentice-Hall, Hemel Hempstead, 1972; pp. 585–634.Google Scholar
  25. 25.
    Duhaime AC, Gennarelli TA, Thibault LE, Bruce DA, Margulies SS, and Wiser R. The shaken baby syndrome. A clinical, pathological, and biomechanical study. J Neurosurg 1987;66:409–415.PubMedCrossRefGoogle Scholar
  26. 26.
    Cory CZ, Jones MD. Can shaking alone cause fatal brain injury? A biomechanical assessment of the Duhaime shaken baby syndrome model. Med Sci Law 2003;43:317–333.PubMedCrossRefGoogle Scholar

Copyright information

© Humana Press Inc 2005

Authors and Affiliations

  • S. Cirovic
    • 1
  • R. M. Bhola
    • 2
  • D. R. Hose
    • 3
  • I. C. Howard
    • 1
  • P. V. Lawford
    • 3
  • M. A. Parsons
    • 4
  1. 1.Department of Mechanical Engineeringthe University of SheffieldSheffieldUK
  2. 2.Academic Unit of Ophthalmology and Orthopticsthe University of SheffieldSheffieldUK
  3. 3.Academic Unit of Medical Physics and Clinical Engineeringthe University of SheffieldSheffieldUK
  4. 4.Ophthalmic Sciences Unitthe University of SheffieldSheffieldUK

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