Open Globe Injuries: Introduction and Evaluation

Shu Yi Teh

Introduction

Open globe injuries (OGI) are defined as a full thickness wound of the eyewall, which can be due to either a rupture or a laceration (1). They can be characterised by mechanism, namely rupture injuries and laceration injuries, and then by anatomic site, which is categorised as zones.

Classification

Open globe rupture occurs following blunt injury to the eye, whereas open globe laceration refers to a penetrating injury to the eye. The former mostly occurs at sites of structural weakness, such as the limbus and near the insertion site of the rectus muscles. The latter is further subclassified into penetrating, perforating, and intraocular foreign body (IOFB) trauma. Penetrating trauma presents with an entry wound but no clearly defined exit wound, whereas perforating injuries have both entry and exit wounds through the eyewall. IOFB injuries are described as a foreign body present anywhere inside the globe and are grouped separately as such injuries have shown to have different prognosis (2,3).

The anatomic region, also known as zones, provides important prognostic information on visual potential of the OGI (4). Zone 1 injury involves the cornea and may extend to the limbus, Zone 2 injury extends posteriorly from the limbus up to 5 mm posterior to the limbus, structures that may be involved include lens and zonules, and Zone 3 injury extends more than 5 mm posterior to the limbus structures that may be involved include retina, optic nerve, and choroid (5).

Epidemiology

The worldwide prevalence of open globe injuries is estimated at 3.5 eye injuries per 100,000 population, with approximately 203,000 cases annually (5). Males comprise approximately 80 percent

of the cases, and those aged between 10 to 30 years are at higher risk (6). There is also increased chance of blunt globe rupture in patients with previous ocular surgery such as large incision phacoemulsification, corneal transplant, and laser-assisted in situ keratomileusis (LASIK) (7-9).

The patterns of globe injury have also been identified in several observational studies (10). Young children are associated more with sharp objects lacerations of the eye, such as scissors, thorns, or writing instruments. Teenage boys commonly sustain blunt injury from sports, motor vehicle collisions, or fights (11). Young men frequently present with penetrating or perforating eye lacerations due to occupational risk from environment like construction sites. Blunt facial trauma due to road traffic accidents and assaults are also prominent aetiologies amongst this demographic (12). Older patients may present more commonly in globe rupture than globe laceration, due to falls with subsequent open globe injury at the site of prior eye surgery (6).

Pathophysiology

Blunt injury

High impact blunt trauma can overwhelm bony protection leading to orbital fractures and globe rupture. The common site of rupture occurs directly behind the insertion of the rectus muscles where the sclera is thinnest and weakest. Other regions like the limbus, optic nerve insertion, and sites of prior eye surgery are also susceptible to rupture (7).

Penetrating injury

Open globe lacerations mostly involve the cornea and approximately one-third of cases are scleral or limbal lacerations. Many globe lacerations are also associated with IOFBs and are commonly found in the vitreous cavity, followed by the anterior chamber, retina, lens, or subretinal space in decreasing prevalence (13).

Extrusion of ocular contents

Increased intraocular pressure predisposes to extrusion of ocular contents after an open globe injury. Risks can be reduced by avoidance of external pressure on the injured eye or Valsalva which may occur secondary to vomiting, by respective shield placement and providing symptomatic relief medications.

Endophthalmitis

Endophthalmitis rates have been reported to be as high as 13 percent in patients with open globe lacerations, especially those complicated by IOFBs (14). Bacillus species and coagulase-negative Staphylococcus are accountable for up to 50 percent of endophthalmitis (4).

Evaluation

History

The involvement of a sharp object, high-velocity projectiles or high-impact blunt trauma should raise the suspicion of an OGI. It is also important to determine the time and place of injury, as ideal time of repair would be within 24 hours of the trauma, and surrounding environments help identify potential wound contamination. Past ocular and surgical history are also pertinent in evaluating the visual potential. However, patients presenting with ocular trauma should first be evaluated for life-threatening injuries and be stabilised as appropriate and send to nearest trauma centre. Potentially lifesaving procedures and surgery take priority over ocular assessment and treatment (15).

External Exam

Ecchymosis, oedema, or superficial lacerations on the face, eyelids, and periocular regions may be present on inspection. Concurrent facial fractures may be suggested by signs of facial asymmetry or bony discontinuities. Protruding foreign bodies present should only be removed when patient is under the controlled conditions of operation room. In addition, care should be taken to minimise manipulation of the globe in suspected OGI and any eyedrop administration should be from a new, sterile bottle (15).

Visual Acuity and Pupils

Visual acuity should be measured to establish a baseline and to prognosticate visual

outcomes. Pupillary examination may provide additional information on the extent of injury. A peaked pupil is often considered pathognomonic for OGI, whereas a dilated pupil may suggest traumatic mydriasis, iris sphincter damage, or possible third nerve palsy. Severe optic nerve damage or retinal injury may be indicated by a relative afferent pupillary defect (15).

Intraocular Pressure (IOP)

Hypotony is highly suggestive of OGI but the possibility of OGI is not eliminated by a normal IOP. However, IOP measurement should be delayed before ruling out an OGI to prevent extrusion of intraocular contents and further damage (15).

Slit-lamp Studies

A detailed inspection of the conjunctiva and sclera should be carried out. Scleral lacerations may be masked by subconjunctival haemorrhage and chemosis. Careful eyelid eversion and gentle sweep of the fornices may be performed to identify for retained foreign material. Thorough inspection of all cornea layers to assess for superficial abrasions, oedema, and lacerations, as well as a Seidel test to

evaluate the thickness of identified lacerations should be done. Examination of the anterior chamber may identify the presence of cells, flare, and hyphema. Both direct and retro-illumination of the iris should be done to assess for tears or breaks. It is also important to evaluate lens position and clarity, as well as the integrity of the lens capsule and zonular fibres. Finally, the posterior segment should be inspected retinal or choroidal detachment, haemorrhage, and possible IOFBs (15).

Diagnostic Imaging

Ancillary imaging studies can help in situations where ocular examination is limited, for structural evaluation of the eye and to identify any foreign body present (15).

Computed Tomography (CT)

Non-contrast orbital CT is the recommended imaging modality for ocular trauma for suspected OGI, to assess globe contour, abnormality of the lens, vitreous haemorrhage, retinal detachment, orbital and facial fractures, obvious orbital volume loss, and suspected metallic IOFB. The sensitivity of CT scan to diagnose an open globe is between 56% and 68% (16).

Ultrasonography

B-scan ultrasonography may be helpful to assess the posterior segment, especially when the funduscopic examination is limited by significant haemorrhage or corneal oedema causing hazy media. However, it should be used carefully to avoid pressure on the globe from the probe, and in many cases, this modality is not recommended prior to globe repair (15).

References

  1. Kuhn, F. et al. (1996) ‘A standardized classification of ocular trauma’, Graefe’s Archive for Clinical and Experimental Ophthalmology, 234(6), pp. 399–403. doi:10.1007/bf00190717.
  2. Zhang, Y. et al. (2011) ‘Intraocular foreign bodies in China: Clinical characteristics, prognostic factors, and visual outcomes in 1421 eyes’, American Journal of Ophthalmology, 152(1). doi:10.1016/j.ajo.2011.01.014.
  3. Andreoli, C.M. et al. (2009) ‘Low rate of endophthalmitis in a large series of open globe injuries’, American Journal of Ophthalmology, 147(4). doi:10.1016/j.ajo.2008.10.023.
  4. Al-Omran, A.M., Abboud, E.B. and Abu El-Asrar, A.M. (2007) ‘Microbiologic spectrum and visual outcome of posttraumatic endophthalmitis’, Retina, 27(2), pp. 236–242. doi:10.1097/01.iae.0000225072.68265.ee.
  5. Pieramici, D.J. et al. (1997) ‘A system for classifying mechanical injuries of the Eye (Globe)’, American Journal of Ophthalmology, 123(6), pp. 820–831. doi:10.1016/s0002-9394(14)71132-8.
  6. Casson, R.J., Walker, J.C. and Newland, H.S. (2002) ‘Four‐year review of Open eye injuries at the Royal Adelaide Hospital’, Clinical & Experimental Ophthalmology, 30(1), pp. 15– 18. doi:10.1046/j.1442-9071.2002.00484.x.
  7. Lambrou, F.H. and Kozarsky, A. (1987) ‘Wound dehiscence following cataract surgery’ Ophthalmic Surgery, Lasers and Imaging Retina, 18(10), pp. 738–740. doi:10.3928/1542-8877-19871001-08.
  8. Vinger, P.F. (1996) ‘Ruptured globes following radial and hexagonal keratotomy surgery’, Archives of Ophthalmology, 114(2), p. 129. doi:10.1001/archopht.1996.01100130123001.
  9. Colby, K. (1999) ‘Management of Open Globe Injuries’, International Ophthalmology Clinics, 39(1), pp. 59–69. doi:10.1097/00004397-199903910-00008.
  10. Rostomian, K. et al. (1998) ‘Open globe injuries in children’, Journal of American Association for Pediatric Ophthalmology and Strabismus, 2(4), pp. 234–238.doi:10.1016/s1091-8531(98)90058-1.
  11. Koo, L. et al. (2005) ‘Gender differences in etiology and outcome of open globe injuries’, The Journal of Trauma: Injury, Infection, and Critical Care, 59(1), pp. 175–178.doi:10.1097/01.ta.0000173624.37438.d6.
  12. Rüfer, F. et al. (2010) ‘Influence of alcohol consumption on incidence and severity of open-globe eye injuries in adults’, Graefe’s Archive for Clinical and Experimental Ophthalmology, 249(12), pp. 1765–1770. doi:10.1007/s00417-010-1533-4.
  13. Williams, D.F. et al. (1988) ‘Results and prognostic factors in penetrating ocular injuries with retained intraocular foreign bodies’, Ophthalmology, 95(7), pp. 911–916. doi:10.1016/s0161-6420(88)33069-1.
  14. Mieler, W.F. et al. (1990) ‘Retained intraocular fore IGN bodies and Endophthalmitis’, Ophthalmology, 97(11), pp. 1532–1538. doi:10.1016/s0161-6420(90)32381-3.
  15. Open globe injury: Assessment and preoperative management (2023) American Academy of Ophthalmology. Available at: https://www.aao.org/eyenet/article/open-globe-injury (Accessed: 23 October 2024).
  16. Arey, M.L. et al. (2007) ‘Computed tomography in the diagnosis of occult open-globe injuries’, Ophthalmology, 114(8), pp. 1448–1452. doi:10.1016/j.ophtha.2006.10.051.

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