Zone of Injury
Zones of Injury are used to classify open- and closed-globe Injuries.
Zone 1- Cornea and Limbus
Zone 2- Limbus to 5mm posterior into sclera
Zone 3- Posterior to 5mm from the limbus
Zone 1- External anterior segment including conjunctiva, sclera and cornea
Zone 2- Internal anterior segment including the lens, zonules and pars plicata
Zone 3- Posterior segment including vitreous, retina, optic nerve, choroid and ciliary body.
Zone of Injury Documentation
When classifying an injury, one always uses the highest zone injury. For example, a corneo-scleral laceration extending to the rectus muscles would be a Zone 3 open-globe injury not a Zone 1, 2, and 3 injury. Again, in a closed globe injury with a conjunctival abrasion, lens dislocation and a retinal detachment, this would be a Zone 3 closed-globe injury, not a Zone 1, 2 and 3 injury.
Multiple studies have shown that Zone 2 and Zone 3 injuries compared to Zone 1 injuries have a worse visual prognosis.
1. Pieramici DJ, Sternberg P Jr, Aaberg TM Sr, Bridges WZ Jr, Capone A Jr, Cardillo JA, de Juan E Jr, Kuhn F, Meredith TA, Mieler WF, Olsen TW, Rubsamen P, Stout T. A system for classifying mechanical injuries of the eye (globe). The Ocular Trauma Classification Group. Am J Ophthalmol. 1997 Jun;123(6):820-31.
2. Pieramici DJ, Au Eong KG, Sternberg P Jr, Marsh MJ. The prognostic significance of a system for classifying mechanical injuries of the eye (globe) in open-globe injuries. J Trauma. 2003 Apr;54(4):750-4.
3. Yalcin Tök O1, Tok L, Eraslan E, Ozkaya D, Ornek F, Bardak Y.Prognostic factors influencing final visual acuity in open globe injuries. J Trauma. 2011 Dec;71(6):1794-800.
4. Vlasov A, Ryan DS, Ludlow S, Weichel ED, Colyer MH. Causes of combat ocular trauma-related blindness from Operation Iraqi Freedom and Enduring Freedom. J Trauma Acute Care Surg. 2015 Oct;79(4 Suppl 2):S210-5.