Penetrating Ocular Trauma

Key points of this disease

• Penetrating eye injury is an open globe injury with only an entry wound, distinguished from perforating injury which has both entry and exit wounds.
• The definition based on the Birmingham Eye Trauma Terminology is the international standard.
• Intraocular foreign body (IOFB) is associated with up to 40% of penetrating injuries, so if an entry wound is found, CT examination should always be performed to search for IOFB.
• Primary repair (wound closure) within 24 hours after injury significantly reduces the risk of endophthalmitis ¹⁾.
• Prognosis is relatively good for injuries confined to the anterior segment, but poor when the posterior segment is involved or when endophthalmitis or PVR complicates.

1. What is penetrating eye injury?

Penetrating eye injury is an open globe injury caused by a sharp object, with only an entry wound and no exit wound. According to the Birmingham Eye Trauma Terminology, it is defined as “if there is only an entry wound and no exit wound, it is penetrating.” Even if there are multiple lacerations, if they result from multiple entry mechanisms, they are classified as penetrating.

Cases with intraocular foreign body (IOFB) are classified separately. Injuries with both entry and exit wounds are distinguished as perforating eye injuries.

Penetrating eye injury

Definition: Entry wound only (no exit wound)

Anterior prolapse of intraocular contents occurs only at the entry site. Relatively less severe than perforating injury.

Perforating eye injury

Definition: Entry wound + exit wound

Because the globe is completely penetrated, intraocular contents prolapse from both front and back, making it more severe.

Intraocular foreign body (IOFB)

Definition: Retention of foreign body inside the eyeball

It occurs in up to 40% of penetrating injuries. CT examination is essential for detection.

Zone Classification of Injury

The location of injury affects prognosis and is classified into the following three zones¹⁾.

Zone	Range	Characteristics
Zone I	Cornea to limbus	Limited to anterior segment. Relatively good prognosis
Zone II	Up to 5 mm posterior to the limbus	Anterior to the ora serrata. Frequent damage to lens and iris
Zone III	More than 5 mm posterior to the limbus	Posterior segment including retina. Often poor prognosis

Comparison of Penetrating and Perforating Injuries

Item	Penetrating	Perforating
Entry wound	Yes	Yes
Exit wound	No	Yes
Ocular content prolapse	Only at entry site (anterior)	Both anterior and posterior
Severity	Relatively mild	Relatively severe
IOFB present	Up to 40%	Rare (falls out after perforation)

Epidemiology

The incidence of open globe injuries is estimated at approximately 3.5 to 4.5 per 100,000 people ¹⁾. The majority of patients are male, with a relative risk about 5.5 times higher than females. The average age at injury is around 30 years. A systematic review of 8,497 eyes with open globe injuries found that the most common injury type was penetrating injury with intraocular foreign body (IOFB) ¹⁾. In children, the incidence is reported as 11.8 per 100,000 per year, and more than 35% of injury cases occur in children.

Q What is the difference between penetrating and perforating injuries?

A

Penetrating injury refers to a wound with an entrance but no exit wound. Perforating injury has both an entrance and an exit wound, completely traversing the globe. Penetrating injuries are relatively less severe, but the rate of intraocular foreign body (IOFB) is up to 40%, requiring careful attention.

2. Main Symptoms and Clinical Findings

Slit-lamp finding of a stellate corneal laceration due to penetrating ocular trauma

Couperus K, Zabel A, Oguntoye MO. Open Globe: Corneal Laceration Injury with Negative Seidel Sign. Clin Pract Cases Emerg Med. 2018;2(3):266-267. Figure 1. PMCID: PMC6075488. License: CC BY 4.0.

A full-thickness stellate laceration in the central cornea, showing a corneal laceration from a penetrating ocular trauma caused by a sharp object. This corresponds to a perforating wound (full-thickness corneal laceration) discussed in the section “Main Symptoms and Clinical Findings.”

Subjective Symptoms

• Eye pain: Occurs immediately after injury. Severity varies depending on the size and location of the perforating wound.
• Vision loss: Caused by corneal damage, hyphema, lens damage, vitreous hemorrhage, etc.
• Foreign body sensation and blurred vision: In minor injuries, these may be the only complaints.
• Redness, photophobia, and tearing: Common symptoms associated with open globe injuries.

Clinical Findings

In penetrating ocular trauma, there is only an entry wound, so there is no prolapse of intraocular contents into the posterior segment, and findings are mainly in the anterior segment.

• Perforating wound: Confirm full-thickness injury of the cornea or sclera.
• Shallow anterior chamber and hypotony: Important signs suggesting aqueous humor leakage.
• Hyphema: May be associated with angle recession or cyclodialysis.
• Pear-shaped pupil: Occurs when the iris is incarcerated in the wound. Suggests iris incarceration (iris trapped in the laceration).
• Iris or uveal prolapse: If the laceration is anterior, uveal tissue may prolapse or become incarcerated through the wound.
• Traumatic cataract: Anterior subcapsular cortical opacity or Vossius ring (ring-shaped pigment deposition on the anterior lens surface) may be observed. Occurs with lens injury.
• Vitreous hemorrhage: Indicates extension of injury to the posterior segment. Common when the injury extends to Zone III.

The Seidel test using fluorescein staining is useful for evaluating full-thickness wounds. Under cobalt blue light, aqueous humor leakage washes away the dye (Seidel positive), confirming a full-thickness wound.

Precautions during examination when open globe is suspected

Tests that apply pressure to the globe are contraindicated. Do not perform forced duction test, gonioscopy, scleral indentation, or B-mode ultrasonography. If there is obvious globe deformation or prolapse of intraocular contents, also avoid measuring intraocular pressure.

3. Causes and Risk Factors

Mechanism of Injury

Home and workplace are the most common locations of injury. The main causes are listed below.

• Sharp objects: knives, scissors, screwdrivers, nails, sticks, etc. In children, writing instruments such as pencils and pens are an important cause.
• High-speed projectiles: metal fragments (from grinders or welding), fragments from hammer strikes, concrete chips, glass shards, etc.
• Blast injuries: A study of ocular trauma from the Beirut port explosion (August 2020) included 39 patients (48 eyes), with open globe injuries in 20.8% and hyphema in 18.8% ²⁾. Penetrating injuries are common due to high-speed fragments from explosives entering the eye.
• Sports-related: baseball/softball, shuttlecocks, BB pellets, etc.

Intraocular foreign bodies (IOFB) occur in up to 40% of penetrating injuries. Metal fragments are most common, but wood and glass fragments are also causes.

Risk Factors

• Male sex: The relative risk of ocular trauma is about 5.5 times higher in males than females.
• Lack of protective equipment: Not wearing eye protection during high-risk work or sports.
• Drug and alcohol use: Increases the risk of injury.
• Children’s writing instruments: Pencils and pens are often perceived as harmless but can cause serious eye injuries.

Infection Risk

The incidence of endophthalmitis in open globe injuries is 2–7%. Infections from plants or soil particularly often lead to blindness. Unlike postoperative endophthalmitis after cataract surgery, endophthalmitis can be caused by virulent organisms such as Bacillus species. In orbital foreign bodies, anaerobic infections (including tetanus) should also be considered.

Prevention and Daily Care

• Always wear protective goggles when using power tools or grinders.
• Supervise children carefully when they handle sharp stationery such as pencils and pens.
• If you feel something has pierced your eye, do not rub or remove it; promptly see an ophthalmologist.

4. Diagnosis and Examination Methods

The diagnosis of open globe injury is made through a combination of detailed history, careful examination, and imaging studies. In penetrating ocular trauma, it is important to suspect retained foreign body in all cases with entry wounds and to actively perform CT scans.

History Taking

Obtain detailed information on the time, mechanism, and causative object of the injury. Also check for the use of protective or prescription glasses, tetanus immunization status, and time of last meal (due to possible general anesthesia). In patients with decreased consciousness, gathering information from family or associates is important. If emergency surgery under general anesthesia is anticipated, secure peripheral intravenous access and instruct the patient to fast.

Ophthalmic Examination

• Visual acuity test: Visual acuity at the initial visit must be measured for prognosis and documentation.
• Pupillary examination: Check for relative afferent pupillary defect (RAPD). Important for detecting traumatic optic neuropathy.
• Slit-lamp examination: Evaluate corneoscleral lacerations, hyphema, and lens damage. Perform Seidel test with fluorescein staining to check for aqueous leakage.
• Fundus examination: Check for traumatic retinal tears, subretinal hemorrhage, and vitreous hemorrhage. If view is poor, use imaging as alternative.

Imaging Studies

Imaging Modality	Main Indications	Notes
Orbital CT	Detection of IOFB, globe deformity, orbital fracture	1 mm thin slices recommended. Indicated for all cases.
B-mode ultrasound	Evaluation of posterior segment when view is poor	Avoid pressure if open globe is suspected
X-ray	Simple detection of metallic foreign bodies	Detectable if length ≥2 mm and thickness ≥0.4 mm
MRI	Non-metallic foreign bodies (e.g., wood)	Contraindicated if magnetic metal is suspected

All penetrating ocular injuries with an entry wound should raise suspicion for a foreign body. CT detection rate for intraocular foreign bodies (IOFB) is reported up to 95%, and it allows simultaneous evaluation of intraocular, orbital fracture, and intracranial lesions.

Q Is CT always necessary for penetrating ocular trauma?

A

If there is an entry wound, always suspect retained foreign body. Intraocular foreign bodies may be present even if anterior segment findings appear normal. CT evaluation for presence, location of foreign body, globe deformation, and orbital fracture is essential; missing it can lead to delayed surgery or blindness.

5. Standard Treatment

The priority in treating penetrating ocular trauma is wound closure (primary repair) to prevent infection and extrusion of ocular contents.

Emergency Treatment

• If the intraocular contents are prolapsed, reposition them completely into the eye.
• Do not remove foreign bodies at the bedside. Apply a rigid eye shield and plan for controlled removal in the operating room.
• If the eyelid wound or conjunctival sac is contaminated, irrigate thoroughly with normal saline.

Primary Repair (Wound Closure)

Primary repair is recommended within 24 hours of injury. A systematic review (8497 eyes, 15 studies) showed that repair within 24 hours significantly reduced the risk of endophthalmitis compared to delayed repair (OR 0.39, 95% CI 0.19-0.79, P=0.01)¹⁾. However, no significant difference in final visual acuity was observed based on repair timing (OR 0.89, 95% CI 0.61-1.29, P=0.52)¹⁾. General anesthesia is typically chosen.

Corneal Suturing

Use 10-0 nylon. Aim for watertight closure, but avoid overtightening sutures to prevent corneal astigmatism or irregular astigmatism; take longer bites. Tighten all sutures evenly to prevent aqueous leakage.

Scleral Suturing

Use 7-0 nylon (6-0 to 8-0 nylon also acceptable). First, secure the four rectus muscles to locate the wound. If the wound is deep and the rectus muscle obstructs, temporarily detach the tendon. Once a part of the rupture wound is found, suture sequentially from the easiest part to ensure closure. For limbal wounds, first suture with 9-0 nylon, then close the corneal wound with 10-0 nylon and the scleral wound with 9-0 nylon using interrupted sutures.

Management of Prolapsed Iris

Management of iris incarceration depends on the extent of damage and contamination.

• Conditions for attempting repositioning: Within 6-8 hours of prolapse and without severe contamination. Prioritize repositioning if the iris tissue is not necrotic.
• Conditions for choosing excision: Tissue necrosis, severe contamination, or difficulty in repositioning.

Prophylactic Antibiotic Administration

Start systemic broad-spectrum antibiotics covering gram-positive and gram-negative bacteria preoperatively. Combination of vancomycin and a third-generation cephalosporin (e.g., ceftazidime) is associated with reduced endophthalmitis rates. If endophthalmitis is suspected, early surgical intervention is recommended. Inject vancomycin 1 mg/0.1 mL and ceftazidime 2.25 mg/0.1 mL into the anterior chamber and vitreous. If vitreous opacification is extensive, perform emergency vitrectomy.

Management of Intraocular Foreign Body

Once the presence of an intraocular foreign body is confirmed, it should be removed as soon as possible. Removal is primarily performed via pars plana vitrectomy using micro forceps or diamond forceps. For detailed treatment strategies, refer to the section on intraocular foreign bodies (IOFB).

Secondary Surgery (Vitrectomy)

Depending on the extent of intraocular tissue damage, lensectomy and vitrectomy may be performed as secondary surgery. In cases of penetrating injury limited to the anterior segment, this may often be unnecessary. However, in the following situations, consider performing these procedures as a single-stage surgery immediately after primary repair.

• When lens swelling has already progressed
• When vitreous hemorrhage is severe and the fundus cannot be visualized
• When an intraocular foreign body remains

Treatment Precautions

• Surgery for penetrating ocular trauma is often very difficult to cure in a single operation, and multiple surgeries may be required.
• Secondary complications such as proliferative vitreoretinopathy (PVR), secondary glaucoma, and endophthalmitis may occur postoperatively.
• Care must be taken not to tighten sutures too much during corneal suturing, as this can cause astigmatism.

Q What is the acceptable time from injury to surgery?

A

Primary repair within 24 hours of injury is strongly recommended. A systematic review has shown that repair within 24 hours significantly reduces the risk of endophthalmitis (OR 0.39, 95% CI 0.19-0.79) ¹⁾. However, no significant difference in final visual acuity has been found when repair is performed within 24 hours.

Q What to do if the iris is prolapsed?

A

If the prolapse is within 6 to 8 hours and there is no severe contamination, attempt iris repositioning. If the tissue is necrotic or heavily contaminated, choose iridectomy. In either case, the procedure must be performed in the operating room; bedside manipulation is contraindicated.

6. Pathophysiology and Detailed Mechanism of Onset

Mechanism of Injury

Penetrating ocular trauma occurs when a sharp object penetrates the eyewall at high speed. It tends to occur at the thinnest parts of the sclera, such as the limbus and posterior to the rectus muscle insertions. Unlike perforating injuries, there is no exit wound, so the eye shape is somewhat preserved without posterior extrusion of intraocular contents. Anterior prolapse (iris incarceration) is the main feature.

Mechanism of Iris Incarceration

Iris incarceration into the laceration results in a pear-shaped pupil. The incarcerated iris closes the anterior chamber to the anterior segment, but if left untreated for a long time, the risk of iris tissue necrosis and infection increases.

Mechanism of Retinal Detachment

There are two mechanisms of retinal detachment in penetrating ocular trauma.

• Direct retinal break formation: External force directly creates a retinal break, and retinal detachment progresses from that site.
• Secondary traction: Vitreous gel incarcerated at the corneoscleral laceration site pulls on the opposite retina, causing retinal tears and detachment.

Secondary Complications

The following secondary changes may occur after initial treatment of the trauma.

• Proliferative vitreoretinopathy (PVR): One of the main causes of poor functional and anatomical outcomes after trauma.
• Traumatic cataract: Caused by penetrating lens injury or blunt impact.
• Secondary glaucoma: Due to hyphema, angle recession, anterior synechiae, etc.
• Endophthalmitis: Occurs in 2–7% of open globe injuries. Onset is often within a few days after injury.
• Sympathetic ophthalmia: A rare complication in which uveitis occurs in the fellow eye triggered by surgery or irritation to the injured eye. It may appear from weeks to years after the injury.

7. Latest Research and Future Perspectives

For patients: Please read carefully

The following content is currently at the research stage or under clinical trial and is not standard treatment available at general hospitals. It is reference information for professionals regarding future medical developments.

Systematic Review on Timing of Primary Repair

McMaster et al. (2025) conducted a systematic review and meta-analysis on the timing of primary repair after open globe injury and its association with visual outcomes and endophthalmitis incidence ¹⁾. The study included 8497 eyes (15 studies), with the most common injury type being penetrating injury combined with IOFB. Repair within 24 hours reduced the risk of endophthalmitis compared to delayed repair (OR 0.39, 95% CI 0.19-0.79, P=0.01). However, no significant difference in final visual acuity was observed based on repair timing (OR 0.89, 95% CI 0.61-1.29, P=0.52). The authors strongly recommend repair within 24 hours, but all included studies were retrospective and non-randomized, and the certainty of evidence was rated low to very low by GRADE assessment.

Prognostic Prediction Using Ocular Trauma Score (OTS)

The Ocular Trauma Score (OTS) is a prognostic tool that estimates the probability of visual outcomes based on initial visual acuity, presence of globe rupture, endophthalmitis, penetrating injury, retinal detachment, and RAPD. In penetrating ocular trauma, prognosis probabilities can be stratified by combining visual acuity, RAPD, and injury zone.

Penetrating Ocular Trauma from Blast Injuries

Kheir et al. (2021) reported 48 eyes of 39 patients with ocular trauma following the Beirut port explosion ²⁾. Open globe injuries were found in 20.8%, hyphema in 18.8%, and surface injuries (conjunctival lacerations, corneal lacerations) in 54.2%. Due to the nature of explosive devices causing multiple tiny fragments to penetrate simultaneously, penetrating injuries are common and often complicated by multiple IOFBs. The importance of CT scanning for all cases to search for IOFBs is emphasized in ophthalmic management of civilian and military blast incidents.

8. References

1. McMaster D, et al. Early versus Delayed Timing of Primary Repair after Open-Globe Injury: A Systematic Review and Meta-Analysis. Ophthalmology. 2025;132:431-441.

2. Kheir WJ, et al. Ophthalmic Injuries After the Port of Beirut Blast. JAMA Ophthalmol. 2021.

3. Germerott T, Mann N, Axmann S. Penetrating eye injury by dart. Int J Legal Med. 2021;135(2):573-576. PMID: 33336294.