Traumatic Wound Dehiscence 22 Years After Penetrating Keratoplasty
A 47-year-old man presents to the emergency department 3 hours after a finger poked his right eye while removing a shirt. He had a penetrating keratoplasty in that eye 22 years earlier for keratoconus; the graft has been clear and he has worn spectacles, not a shield, for years. Vision is counting fingers at 1 metre. There is a 4 mm full-thickness wound dehiscence at the graft-host junction inferonasally, with a shallow anterior chamber, iris prolapse through the wound, and a formed but soft globe. B-scan is not yet done. He is on no medication, has no other injuries, and is systemically well. The on-call resident asks whether to repair in theatre tonight, and whether the host rim should be trimmed.
1. Outline your immediate management priorities and justify the sequence.
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Priorities in order:
- Protect the globe and prevent further prolapse - rigid shield, no pressure, no forced lid opening, avoid Valsalva (antiemetics, analgesia, avoid straining). Do not manipulate the prolapsed iris at the slit lamp.
- Systemic antibiotics - IV cefazolin plus gentamicin (or a fluoroquinolone if penicillin-allergic) covering skin and oral flora, plus tetanus prophylaxis. An open globe with uveal exposure is an infection risk even if the wound is small.
- Nil by mouth and theatre tonight - this is a full-thickness dehiscence with iris prolapse and a flat chamber; conservative management is not an option.
- Imaging only if it changes management - CT orbit if intraocular foreign body or orbital fracture is suspected; B-scan after closure if posterior segment cannot be seen.
Reasoning: the eye is currently formed (soft but not collapsed), which is the window to act before expulsive haemorrhage or endophthalmitis. Every hour of iris incarceration increases synechial damage and endothelial loss; the iris should be reposited within hours, not days.
2. At surgery, how do you decide whether to excise the prolapsed iris, and how do you close the wound in a 22-year-old graft?
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Iris: Reposit if the tissue is clean, viable, and the pupil can be reformed without tension - typically within 24–48 hours of a sharp, clean injury. Excise if the iris is necrotic, heavily contaminated, or so macerated it will not hold a suture or will seed infection. Here the injury is 3 hours old from a fingernail, so gentle reposition with an iris spatula and acetylcholine is reasonable; excise only frankly non-viable tags.
Wound closure:
- Debride only loose, non-viable host tissue; do not trim healthy host rim - you will widen the defect and worsen astigmatism.
- Place interrupted 10-0 nylon sutures, 50–75% depth, radial to the wound, with knots buried. Use a larger bite on the host side if the host rim is thin.
- Aim for watertight closure with a formed chamber; test with balanced salt solution and consider a small air or viscoelastic fill.
- Re-form the anterior chamber and check the pupil is round and not peaked to a suture.
- Do not attempt to exchange the graft acutely unless the graft itself is disintegrating - a clear 22-year-old graft with an intact endothelium is worth preserving.
Post-operatively: topical steroid and antibiotic, shield, and a suture removal plan over months with topography-guided timing, because graft-host junction sutures induce irregular astigmatism.
3. What long-term counselling does this patient need, and what does this case teach about graft dehiscence risk?
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Counselling:
- Lifetime risk of dehiscence at the graft-host junction persists indefinitely - the scar never regains normal tensile strength. He needs a polycarbonate shield/spectacles at all times, including at home and at work, and should be advised against contact sports without a helmet/face guard.
- Warn about symptoms of a wound leak (watery eye, shallowing, sudden blur) and to present immediately.
- Long-term follow-up for graft rejection, astigmatism, and suture-related problems; refractive correction once stable.
Teaching points:
- The graft-host interface is the weakest point of the eye forever; even minor blunt or sharp trauma can cause full-thickness dehiscence decades later.
- Patients often abandon protective eyewear once the graft 'has taken'; this is the commonest reason for late catastrophe.
- Management is a time-critical surgical emergency: shield, antibiotics, theatre, watertight closure, preserve the graft and the iris where possible.