title: Eye injury risk from water stream impact: biomechanically based design parameters for water toy and park design.
abstract: OBJECTIVE
  Interactive water displays are becoming increasingly popular and can result in direct eye contact. Therefore, the purpose of this study is to investigate eye injury risk from high speed water stream impacts and to provide biomechanically based design parameters for water toys and water park fountains.
  
  
  METHODS
  An experimental matrix of 38 tests was developed to impact eight porcine eyes with water streams using a customized pressure system. Two stream diameters (3.2 mm and 6.4 mm) were tested at water velocities between 3.0 m/s and 8.5 m/s. Intraocular pressure was measured with a small pressure sensor inserted through the optic nerve and used to determine the injury risk for hyphema, lens dislocation, retinal damage, and globe rupture for each impact.
  
  
  RESULTS
  Experimental water stream impacts created a range of intraocular pressures between 3156 mmHg and 7006 mmHg (61 psi to 135 psi). Injury risk varied between 4.4%-27.8% for hyphema, 0.0%-3.0% for lens dislocation, and 0.1%-3.3% for retinal damage. All tests resulted in 0.0% injury risk for globe rupture. The two water stream diameters did not result in significantly different water stream velocities (P = 0.32); however, the variation in water stream diameter did result in significantly different intraocular pressures (P = 0.03) with higher pressures for the 6.4 mm stream.
  
  
  CONCLUSIONS
  This is the first study to experimentally measure intraocular pressure from high speed water stream impacts and quantify the corresponding eye injury risk. It is recommended that toy water guns and water park fountains use an upper threshold of 8.5 m/s for water stream velocities to minimize the risk of serious acute eye damage from impacts.
authors.affiliation: Center for Injury Biomechanics, Virginia Tech-Wake Forest University, Blacksburg, VA 24061, USA. duma@vt.edu
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Duma
authors.forename: Jill A
authors.initials: JA
authors.lastname: Bisplinghoff
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Senge
authors.forename: Craig
authors.initials: C
authors.lastname: McNally
authors.forename: Vanessa D
authors.initials: VD
authors.lastname: Alphonse
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D004867:Equipment Design; D005131:Eye Injuries / Q000175:diagnosis / Q000503:physiopathology* / Q000517:prevention & control; D007429:Intraocular Pressure; D010988:Play and Playthings / Q000293:injuries*; D011312:Pressure / Q000009:adverse effects; D012307:Risk Factors; D013552:Swine; D015599:Trauma Severity Indices; D014867:Water
chemical_list: D014867:Water