Posterior segment manifestations of penetrating ocular trauma

Ghanbari MD

87:11:30

A standard classification of oculartrauma. Ophthalmology 1996; 103:240-243.

Ocular trauma is a major cause of ocular morbidity and the leading cause of monocular visual loss.

Open globe rupture : occurs following blunt eye injury at the site of greatest structural weakness.

The initial of injury to the macula or optic nerve is critical for determining visual prognosis.

Ocular trauma: Initial injuries Secondary complications Wound healing Endophthalmitis Sympathetic ophthalmia

Primary damages: Vitreous Retina Macula Optic nerve Vesseles

Vitreous incarceration

(a) Postoperative colour fundus photo showing a laceration of the vessels at the superior aspect of the optic disc. (b) Close-up of the superior arcade showing retinal pallor, cotton wool spots and dot/blot haemorrhages.

(a) Colour fundus photo 6 months post-injury showing scarring and retinal striae extending across papillomacular bundle.(b) Close-up of the optic disc showing fibrotic scarring.

Gunshot wound

Giant retinal tear with retinal vessels crossing the tear. View through a superfield

Retinal incarceration in the posterior impact site (arrow) and the subretinal blood (curved arrow). A localized choroidal hemorrhage is seen in the foreground on the left

10  Traumatic endophthalmitis (Streptococcus faecalis) at presentation after penetrating trauma. Note the marked anterior chamber fibrin, early ring infiltrate of the cornea, peripheral hypopyon, and purulent material in the area of corneal laceration

Factors associated with Endophthalmitis Open globe laceration. Retained IOFB. Injury by organic material. Disruption of the lens.

Delay in primary closure.

Endophthalmitis:  2 to 7 percent for all open globe injures. This rate is as high as 13 percent in patients

with open globe lacerations complicated by IOFBs

Bacillus species and coagulase-negative Staphylococcus account for up to 50 percent of endophthalmitis after open globe injury based on intraoperative cultures.

Wound healing Infiltration Proliferation Scar formation

Subsequent wound healing

Intraocular proliferation, and post-traumatic PVR.

TRD

Among 327 patients who had an open-globe injury, PVR occurred in 64 patients (20% of eyes), with the highest frequency following perforating injury (43%).

Prognosis

Severity of the initial penetrating injury. Initial visual acuity.    RAPD.   Injuries associated with blunt trauma.   Large corneoscleral laceration.    Presence of infection.Lens damage.

OPEN-GLOBE INJURIESPreoperative evaluationVA.RAPD.IOP.VEP,ERG.Ultrasonography.CT Scan.MRI.

An open globe often has low IOP, but normal or elevated IOP does not rule out the possibility of a rupture.

Diffuse chemosis or subconjunctival hemorrhage suggests the presence of occult scleral rupture.

Repair

Running shoelace monofilament nylon sutures distribute stress evenly, are elastic and well tolerated, and may be rapidly placed.

Silk sutures are inelastic and lead to wound leaks during the vitrectomy

Absorbable sutures are inelastic and not permanent.

PATHOBIOLOGY OF WOUND HEALING

Open-globe injury, resulting: Intraocular blood. Inflammatory cell infiltration.Blood-retina barrier breakdown.

ChemokinesCytokinesGrowth factors Effects on the RPE. Fibroblasts. Glial cells.

PATHOBIOLOGY OF WOUND HEALING

Some cells develop Contractile Elements; then organized and TRD occurs.

PATHOBIOLOGY OF WOUND HEALING

Factors highly associated with RD

Blood in vitreous.Injuries involve ora serrata.

Management

Creation of posterior vitreous detachment by a vitreoretinal pick

Retinal dialysis caused by traction of shrinking membrane. Location of scleral laceration (A). Vitreous membrane (B). Dialysis at vitreous base border (C).

Role of Vitrectomy

Vitrectomy is indicated:Traumatic open-globe injuries with RD on

presentation. Double-penetrating injuries.Vitreous incarceration.Vitreous hemorrhage.IOFBs.Endophthalmitis.

MAGNETIC INTRAOCULAR FOREIGN BODIES External magnet may have a place in the

management of IOFBs that are Well visualized. Small. Intravitreal in location.

If signs of tissue incarceration and or fibrous encapsulation of the IOFB are present.

vitrectomy

Removal of encapsulated intraocular foreign body

Timing of vitrectomyMost surgeons will agree that immediate

vitrectomy is indicated for posttraumatic endophthalmitis or IOFB with high risk of infection, but

timing of surgery with other scenarios is less clear.

Cleary and Ryan compared vitrectomy at 1, 14, and 70 days after a standardized injury with intravitreal autologous blood injection known to cause a reproducible tractional retinal detachment.

Timing of vitrectomy

By day 70, most eyes already had a RD, but prevention of retinal detachment was documented with vitrectomy at both 1 and 14 days post-injury.

Whereas there was no significant difference between vitrectomy at 1 and 14 days with regard to its ability to prevent retinal detachment, it was noted that surgery at 1 day was technically more difficult.

By day 14, a posterior vitreous detachment had occurred in many cases and the vitreous was generally easier to cut.

Timing of VitrectomyVitrectomy should be performed between 7

and 14 days after injury. unless Angle closure from lens swelling. Endophthalmitis. Ultrasonic evidence of RD does not

necessarily indicate early vitrectomy.

Timing of Vitrectomy

PVD to occur. Decreases choroidal swelling.Decreases bleeding.Better corneal clarity.Less wound leakage. liquefaction of the clot.

Prophylactic Cryotherapy CryotherapyBlood-retinal barrier breakdown .Enhances intravitreal dispersion of RPE

cells, and PVR.

Do not recommend prophylactic cryotherapy to the edges of a posterior scleral wound without visualization of the retina, especially when the lack of visualization is caused by a vitreous hemorrhage.

If the retina is visible and retinal pathology is present that requires treatment, then we recommend prophylactic indirect laser photocoagulation.

Prophylactic Scleral BuckleSome authors have recommended that

all eyes that undergo vitrectomy for open-globe injuries should have an encirling scleral buckle placed at the time of surgery, even if no retinal detachment is present.

Prophylactic Antibiotics

Endophthalmitis: Overall (2%–11% of cases).Rural setting (30%). IOFB (10%–15%).More virulent organisms such as

Bacillus

prophylactic intravitreal antibiotic injections should be used only when there are clinical signs of infection, or when there is high risk of infection from organic matter contamination.

vancomycin (1.0 mg) and ceftazidime (2.25 mg), or vancomycin alone.

Medications

IV vancomycin or a combination of vancomycin with ceftazidime for 1–3 days followed by oral ciprofloxacin for 10–14 days as prophylaxis against infection.

Vitrectomy Versus Vitreous Tap forTraumatic Endophthalmitis

Multiple and more virulent organism.

Open-globe injury have concurrent intraocular damage, requiring vitrectomy repair.

Concurrent IOL Implantation

Excellent outcomes seen with secondary IOL.

Significant risk of endophthalmitis. RD. PVR in traumatized eyes.Rarely recomended placement of a

primary IOL in the acute setting of an open globe injury.

THE END