Ocular Penetrating and Perforating Injuries

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Article initiated by:

Sayjal J. Patel M.D.

All contributors:

Brad H. Feldman, M.D., Vinay A. Shah M.D., Anna Murchison, MD, MPH, Grant A. Justin, MD, Paul R Parker, MD, Jason Hsu, MD, Jennifer I Lim MD, Sayjal J. Patel M.D., Boonkit Purt, MD, Grayson W Armstrong MD MPH

Assigned editor:

Grayson W Armstrong MD MPH, Jason Hsu, MD

Review:

Assigned status Update Pending

 by Grayson W Armstrong MD MPH on March 3, 2024.

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Disease Entity

Disease

Ocular penetrating and perforating injuries (commonly referred to as open globe injuries) can result in severe vision loss or loss of the eye. Penetrating injuries by definition are caused by a sharp object that penetrates into the eye (i.e. laceration) but not through and through--there is no exit wound. Perforating injuries go 'through and through' the eye and therefore have both an entrance and an exit wound. Typically, to constitute one of these injuries, a full-thickness wound through the cornea and/or sclera must be present. Open globe rupture, in contrast, refers to blunt injury of the eye causing sudden increase in intraocular pressure resulting in eye wall dehiscence and ultimately globe collapse. These terms are used to standardize the nomenclature associated with severe ocular trauma. This typically occurs at the limbus and near the equator behind the recti muscles insertions, where the sclera is thinnest. This can also occur at sites of prior intraocular surgery due to potential iatrogenic lack of tissue integrity at these sites. The injury is further classified based on three zones: I, II, and III (see Zone of Injury). Zone I involves the cornea up to the limbus, Zone II involves the sclera from the limbus back to 5mm beyond the limbus, which anatomically is ~5mm anterior to the ora serrata that does not extend into the retina, and Zone III refers to any injury greater than 5mm beyond the limbus, which results in anatomic injuries posterior to the ora serrata that involve the retina.

Etiology

Penetrating or perforating ocular injuries can be due to injury from any sharp or high velocity object. Most individuals sustaining eye injuries are male with an estimated relative risk of 5.5 times greater than women. Average age of the patient is typically in their 30s. The home and workplace are the most frequent locations for injuries, and the most common situations were domestic assaults, battery assaults, and workplace accidents. The most common blunt objects reported by May et al from the United States Eye injury Registry were rocks, fists, baseballs, lumber and fishing weights. Paintball and BB guns are also common in the teenage demographic. In the elderly, globe rupture is actually more common typically from falls and structural weakening of the eye with age. The most common sharp objects were sticks, knives, scissors, screwdrivers and nails. When one of these objects becomes lodged in the eye, it is referred to as an intraocular foreign body (IOFB), which occurs in up to 40% of ocular penetrating or perforating injuries (see Intraocular Foreign Bodies (IOFB)).

Risk Factors

As noted from the epidemiological studies above, male gender is a large risk factor for ocular trauma. Failure to wear adequate eye protection while performing high risk activities such as baseball, basketball and use of power tools in the home environment have also been noted to be risk factors for eye injuries. Substance abuse, including alcohol and marijuana, is also known to increase the risk of eye trauma.

Primary prevention

Appropriate and adequate eye protection when performing visually threatening activities is the most effective method to prevent ocular trauma. Avoiding high-risk activites is also an effective method of prevention. The American Academy of Ophthalmology Eye Injury Snapshot is a yearly survey designed to collect data and educate the public about the causes and prevention of eye injuries. Through educational programs such as this, potential eye injuries may be prevented.

Diagnosis

History

It is important to obtain a thorough history from the patient to help identify the timing of the injury and mechanism. Any injuries other than the eye should be ascertained. Questions such as what the patient was doing during the injury and what potential objects could have caused the injury are important prior to physical evaluation. It is important to note whether safety glasses or prescription eyeglasses were being worn at the time of the injury. Also, make sure to ask the patient if he/ she has a history of limited vision in either eye (amblyopia or other prior cause of visual loss).

A pertinent medical history including current medications, allergies, tetanus status, and timing of last meal can help with diagnosis and management. Prior ocular history and ocular surgical history is also important to obtain.

Symptoms

Patients with penetrating or perforating injuries usually complain of pain, vision loss, or double vision. In more subtle injuries, there may be minor symptoms such as foreign body sensation or blurred vision. Severe redness, light sensitivity, and foreign body sensation are also symptoms of open globe injuries.

Signs

Subconjunctival hemorrhage, shallow or flat anterior chamber, hyper-deep anterior chamber, peaked pupil, corneal or scleral discontinuity, hyphema, iris deformities, uveal prolapse, lens disruption, or posterior segment findings such as vitreous hemorrhage, retinal tears, or retinal hemorrhage are concerning when seen in a patient with suspected trauma.

Physical examination

Ophthalmic examination after severe trauma can be difficult. Obtaining a visual acuity and pupillary examination may be the most important elements to ascertain, though tonometric measurement of intraocular pressure should be avoided given it places pressure on the globe and may result in extrusion of intraocular contents. Obvious trauma requires careful handling of the eye with care taken to prevent any pressure on the globe if an open globe is suspected; exam maneuvers commonly conducted that exert such pressure are contraindicated, such as forced ductions, gonisocopy, scleral depression, and B-scan. Moreover, eyedrops should be avoided in cases of obvious penetrating or perforating injury. The adnexa should be carefully examined with delicate palpation of the orbital rim.

Once an extraocular muscle and external examination is complete, a thorough conjunctival and anterior segment examination must be completed if penetrating or perforating injury is suspected. A posterior exam should be done to look for intraocular damage as long as there is a view through the pupil.

Full thickness corneal lacerations often result in leakage of aqueous humor from the anterior chamber. Applying fluorescein dye to the suspected corneal wound is called a 'seidel test' and can be used to assess for full thickness lacerations in cases where it may not be obvious. In these cases, the fluorescein dye under cobalt blue light will be 'washed away' by the aqueous humor leaking from the full thickness wound and confirms the presence of a full thickness wound. If the fluorescein dye is washed away, the wound is considered 'seidel positive', while lack of fluid coming from the wound means it is 'seidel negative'. An example video of a 'seidel positive' exam can be found here. Similar testing can sometimes be performed on the sclera and conjunctiva, though vitreous may plug scleral wounds and cause a lack of seidel positivity.

Diagnostic procedures

Computed tomography (CT) scans of the orbits are indicated to assess for intraocular foreign body, especially in cases of poor views to the vitreous and retina. It is important to obtain thin 1 mm CT cuts in the axial, coronal, and sagittal planes to rule out IOFB, which can be present in up to 40% of penetrating ocular injuries. When direct visualization is not possible, gentle ultrasound can be considered to evaluate the globe, though extreme caution should be used as the pressure from the ultrasound device and cause extrusion of intraocular contents. Ultrasonography can be helpful when the media preclude a posterior exam, and has been shown to have a 100% positive predictive value for diagnosing retinal detachment and IOFB. If there is a suspicion for an IOFB, magnetic resonance imaging (MRI) is contraindicated. MRI is also contraindicated in any case where a metal object is thought to be involved.

Management

General treatment

Penetrating or perforating injuries should be evaluated and treated immediately. Depending on the material causing the injury and location of entry, severe vision loss can occur. The Ocular Trauma Score (OTS) was developed in 2002 from a cohort of 2500 eye injuries and visual recovery as a way to assess prognosis of visual recovery post injury. A raw score from 0-100 is calculated based on initial post-injury VA, rupture of the globe, endophthalmitis, penetration of the globe, presence of retinal detachment, and presence of afferent pupillary defect to then determine a final score of 1-5. This can be used to determine chance of visual recovery. In one study of 93 patients with combat-related penetrating and perforating injuries, OTS model predicted visual survival (LP or better) with a sensitivity of 94.80% and predicted no vision (NLP) with a specificity of 100%. Risk of endophthalmitis should be assessed (higher risk with rural settings, IOFB), and prophylaxis given with systemic, topical, and/or intravitreal broad spectrum antibiotics covering both Gram positive and negative organisms. Systemically, vancomycin and a third-generation cephalosporin such as ceftazidime are used, which have been associated with a low risk of endophthalmitis. Prophylactic intravitreal antibiotics following surgical repair have been found to reduce the risk of endophthalmitis.

If surgical exploration is planned, a fox shield, anti-emetics, analgesics, intravenous antibiotics, and update of tetanus status should be completed. The patient should be made NPO immediately in preparation for emergent surgery. The patient should be put on bed rest and instructed to avoid any exertion. It is critical for anesthesia to be aware not to use high dose ketamine for sedation and not to use succinylcholine for paralysis, as these medications can increase intraocular pressure and cause expulsion of intraocular contents.

A plan for prompt surgical repair within 24 hours of the injury is crucial whenever possible, as this has been shown to have a lower risk of endophthalmitis compared to delayed repair. However, timing of surgery within the 24 hour window has not been found to be associated with visual outcomes.

Surgery

In cases with a high suspicion for penetrating or perforating eye trauma, globe exploration should be performed with possible vitrectomy if vitreous hemorrhage with an intraocular foreign body or retinal detachment is present. In cases of confirmed penetrating or perforating eye trauma, prompt closure of the open globe is recommended primarily focusing on anterior segment structures, with all attempts made to restore the entire wall of the eye to its pre-trauma state.

Lacerations of the cornea require careful reapproximation of corneal tissue with care to reform the anterior chamber to its prior state while minimizing astigmatism and scar. Tips on addressing corneal wound repair can be found in this video-based open globe curriculum in the chapters dedicated to corneal repair. Typically, corneal tissue should be repaired with 10-0 nylon sutures in an interrupted fashion using slip knots (video here).

Scleral lacerations also require care and attention and are repaired using 8-0 nylon sutures tied using surgeons knots (video here). Tips on addressing scleral wound repair can be found in this video-based open globe curriculum in the chapters dedicated to scleral wound repair. Care to reposit uveal and retinal tissue without further iatrogenic damage is critical when repairing scleral wounds.

Any subsequent procedures needed to restore the anterior segment (e.g. penetrating keratoplasty, secondary intraocular lens) are performed at a later date when the eye is stable. Any eyelid trauma should be repaired after repair of the globe injury, as pressure placed on the eyelids during repair can extrude globe contents. In addition, eyelid trauma can sometimes improve exposure of the globe injury. Postoperatively, the eye should be monitored carefully with exams and ultrasound until any vitreous hemorrhage resolves or indications for pars plana vitrectomy occur (tractional and/or rhegmatogenous retinal detachment). For eyes in which the vitreous cavity has been violated on presentation, pars plana vitrectomy is frequently performed to avoid tractional retinal detachment when vitreous organization is seen.

Complications

One important consideration is the risk of retinal detachment, both in the immediate timeframe and following presentation. In one retrospective chart review, retinal detachment (RD) occurred in 29% of open globe injuries. Of these eyes with RD, 27% detached within 24 hours of primary open globe repair, 47% detached within 1 week, and 72% detached within 1 month. Risk factors for RD post open globe repair included presence of vitreous hemorrhage, higher zone of injury, and worse presenting visual acuity. The same cohort of patients were used to devise a low, moderate, and high risk scoring system for predicting this risk, the Retinal Detachment after Open Globe Injury (RD-OGI).

Eyes must also be assessed for wound leak post operatively. In one review, 16% of eyes developed wound leak post-operatively. Factors associated with higher risk of wound leak post-repair were delayed presentation as well as a stellate shaped wound. Wound leak was also found to be a risk factor for endophthalmitis, which is another important complication post-operatively that can be minimized with the use of prophylactic antibiotics and repair within 24 hours of injury.

Prognosis

There are a number of risk factors on initial presentation that can be used to predict ultimate visual prognosis following an ocular penetrating or perforating injury. By far the most predictive prognostic factor is the initial visual acuity on presentation, as well as injury to zone III, history of corneal transplantation, presence of RAPD, time from injury, and presence of retinal detachment and/or vitreous hemorrhage, and crystalline lens dislocation. The OTS is also a useful tool to get an idea of visual recovery potential.

It is important to be clear with patients regarding degree of visual recovery and future options depending on the type of injury. Corneal transplantation, traumatic cataract extraction with insertion of an intraocular lens implant, or further posterior segment procedures may be required following the initial operation repair. Sympathetic ophthalmia, a bilateral diffuse granulomatous uveitis that often follows ocular trauma due to violation of the eye's immune privilege, is an important though rare consequence to consider (see Sympathetic Ophthalmia). In eyes with pain where visual recovery is unlikely, enucleation or evisceration should be considered to prevent injury to the non-injured eye.