Penetrating Ocular Trauma

Key points of this disease

• A penetrating eye injury is an open globe injury with only an entrance wound, distinguished from a perforating injury which has both entrance and exit wounds.
• The definition based on the Birmingham Eye Trauma Terminology is the international standard.
• Because intraocular foreign bodies (IOFB) may be present, CT scanning for IOFB should be considered when an entrance wound is identified ⁴⁾.
• Primary repair (wound closure) within 24 hours of 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 the injury.

1. What is a Penetrating Eye Injury?

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

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

Penetrating Eye Injury

Definition: Entrance wound only (no exit wound)

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

Perforating Eye Injury

Definition: Entrance 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 a foreign body inside the eyeball

May be associated with penetrating trauma. CT examination should be performed as needed.

Zone of Injury Classification

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

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

Comparison of Penetrating and Perforating Injuries

Item	Penetrating	Perforating
Entry wound	Present	Present
Exit wound	Absent	Present
Ocular content prolapse	Only at entry (anterior)	Both anterior and posterior
Severity	Relatively mild	Relatively severe
IOFB present	May be present	Rare (falls out after perforation)

Epidemiology

The incidence of open globe injury is estimated at approximately 3.5–4.5 per 100,000 population ¹⁾. The majority of patients are male, with a relative risk about 5.5 times higher than females. The average age at injury is about 30 years. A systematic review of 8,497 eyes with open globe injury 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, with over 35% of injuries occurring in children.

Q What is the difference between penetrating and perforating injuries?

A

Penetrating injury refers to a wound with an entry site but no exit site. Perforating injury has both an entry and an exit wound, completely traversing the eye. Penetrating injuries are relatively less severe, but attention must be paid to the possibility of intraocular foreign body (IOFB).

2. Main Symptoms and Clinical Findings

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 is seen in the central cornea, indicating a corneal laceration from penetrating ocular trauma 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 injury, 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 injury.

Clinical Findings

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

• Perforating wound: Confirm full-thickness damage to the cornea or sclera.
• Shallow anterior chamber and low intraocular pressure: Important findings suggesting aqueous humor leakage.
• Hyphema: May be accompanied by 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: When the laceration is anterior, the uvea may prolapse or become incarcerated through the wound.
• Traumatic cataract: Anterior subcapsular cortical opacity or Vossius ring (a ring-shaped pigment deposit on the anterior lens surface) may be observed. Occurs with lens damage.
• Vitreous hemorrhage: Indicates extension of damage 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 testing, gonioscopy, scleral depression, or B-scan ultrasonography. If there is obvious globe deformation or extrusion of intraocular contents, also avoid measuring intraocular pressure.

3. Causes and Risk Factors

Mechanism of Injury

The 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), chips from hammering, concrete fragments, glass shards, etc.
• Blast injuries: In an ocular trauma study of the Beirut port explosion (August 2020), 39 patients (48 eyes) were included, with open globe injuries in 20.8% and hyphema in 18.8% ²⁾. Penetrating injuries are common due to high-velocity fragments entering the eye from explosives.
• Sports-related: baseball/softball, shuttlecocks, BB pellets, etc.

Intraocular foreign bodies (IOFB) can complicate penetrating trauma. 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 trauma.
• Children’s writing instruments: Pencils and pens are often perceived as harmless but can cause serious eye injuries.

Infection Risk

The frequency of endophthalmitis in open globe injuries is 2–7%. Infections, especially from plants or soil, 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 (e.g., 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 pull it out; promptly see an ophthalmologist.

4. Diagnosis and Examination Methods

Diagnosis of open globe injury involves a combination of detailed history taking, careful examination, and imaging studies. In penetrating ocular trauma, suspect retained foreign bodies, and consider CT if examination is insufficient or if intraocular foreign body (IOFB) is suspected ⁴⁾.

History Taking

Obtain detailed information on the time, mechanism, and causative object of the injury. Also check for use of protective or prescription glasses, tetanus immunization status, and time of last meal (due to possible general anesthesia). In patients with reduced 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 testing: Measure visual acuity at the initial visit 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 humor leakage.
• Fundus examination: Check for traumatic retinal tears, subretinal hemorrhage, and vitreous hemorrhage. If view is poor, use imaging as an alternative.

Imaging Studies

Imaging modality	Main indications	Notes
Orbital CT	Detection of IOFB, globe deformity, orbital fracture	Non-contrast orbital or facial CT is standard 4)
B-mode ultrasound	Posterior segment evaluation 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

In penetrating ocular trauma with an entry wound, suspect a foreign body. CT can simultaneously evaluate intraocular foreign bodies (IOFB), globe deformation, orbital fractures, and intracranial lesions, making it useful when assessment by clinical findings alone is difficult ⁴⁾.

Q Is CT necessary for penetrating ocular trauma?

A

If there is an entry wound, suspect retained foreign body. Even if anterior segment findings appear normal, an intraocular foreign body may be present. CT evaluation of the presence and location of foreign bodies, globe deformation, and orbital fractures is important; missing these can lead to delayed surgery or blindness ⁴⁾.

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 iris or uveal tissue is prolapsed, attempt repositioning in the operating room if there is no necrosis or severe contamination. Manage prolapsed vitreous with anterior vitrectomy.
• 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 saline.

Primary Repair (Wound Closure)

Aim for primary repair 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 used.

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 is found, suture sequentially from the easiest area 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.

Antibiotic Prophylaxis

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 invasive treatment 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 microforceps or diamond forceps. Detailed treatment strategies for intraocular foreign bodies are covered in the article on intraocular foreign bodies (IOFB).

Secondary Surgery (Vitrectomy)

Depending on the extent of damage to intraocular tissues, 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 it as a single-stage procedure immediately following 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 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 overtighten sutures during corneal suturing, as this can cause astigmatism.

Q What is the acceptable time from injury to surgery?

A

Primary repair should be aimed for within 24 hours of injury. 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 based on the timing of repair 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. Both procedures 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 eye wall 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 extrusion (iris incarceration) is the main feature.

Mechanism of Iris Incarceration

Iris incarceration at the laceration site results in a pear-shaped pupil. The incarcerated iris seals the anterior chamber anteriorly, 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 tear formation: A direct force creates a retinal break, from which retinal detachment progresses.
• Secondary traction: Vitreous gel incarcerated at the corneoscleral laceration site pulls on the opposite retina, causing a retinal tear and retinal 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, or anterior synechiae.
• Endophthalmitis: Occurs in 2–7% of open globe injuries. Onset is usually 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 this

The following content is currently under research or in clinical trials 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 rates 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). All included studies were retrospective and non-randomized, with the certainty of evidence rated as low to very low.

Prognosis prediction using the 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 relative afferent pupillary defect (RAPD). In penetrating ocular trauma, prognosis 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 injury was found in 20.8%, hyphema in 18.8%, and surface injuries (conjunctival laceration, corneal laceration) 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. In civilian and military blast incidents, CT is crucial for detecting IOFBs.

8. References

1. McMaster D, Bapty J, Bush L, Serra G, Kempapidis T, McClellan SF, et al. Early versus Delayed Timing of Primary Repair after Open-Globe Injury: A Systematic Review and Meta-analysis. Ophthalmology. 2025;132(4):431-441. doi:10.1016/j.ophtha.2024.08.030. PMID:39218161.

2. Kheir WJ, Awwad ST, Bou Ghannam A, Khalil AA, Ibrahim P, Rachid E, El Salloukh NA, Yehia M, et al. Ophthalmic Injuries After the Port of Beirut Blast-One of Largest Nonnuclear Explosions in History. JAMA ophthalmology. 2021;139(9):937-943. doi:10.1001/jamaophthalmol.2021.2742. PMID:34351374; PMCID:PMC8343520.

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

4. Zhou Y, DiSclafani M, Jeang L, Shah AA. Open Globe Injuries: Review of Evaluation, Management, and Surgical Pearls. Clinical Ophthalmology. 2022;16:2545-2559. doi:10.2147/OPTH.S372011. PMID:35983163; PMCID:PMC9379121.