Graft Infection – Viral Reactivation With Superadded Bacterial Keratitis

This case report highlights that even after penetrating keratoplasty for reasons unrelated to herpes simplex virus (HSV) keratitis, any nonspecific epithelial defect may still be caused by HSV. Late-onset epithelial defects after penetrating keratoplasty may result from trauma, contact lens use, medication toxicity, ocular surface disorders, viral keratitis reactivation, or acute epithelial rejection.Predisposing factors for viral reactivation include topical and systemic corticosteroid use and local trauma, such as penetrating keratoplasty or suture removal. Reactivation may be triggered by surgical trauma, leading to viral shedding in the tear film, corneal infection, and a large geographic epithelial defect.

Dr Rajendra prasad centre for ophthalmic sciences ,AIIMS, New Delhi

A 50-year-old male with a history of bacterial keratitis and adherent leucoma in the left eye underwent an optical triple procedure on 20/06/2023. One month later, he presented with redness, pain, and blurred vision for one day with no history of trauma . Visual acuity was 6/36, IOP 12 mmHg. Anterior sgement evaluation showed a total epithelial defect with a 2 × 1.5 mm infiltrate at 7 o’clock. The graft-host junction was well-apposed, sutures intact, and no anterior chamber reaction.

Investigations

AS-OCT showed increased graft thickness (794 microns). Corneal scraping identified Gram-positive cocci. Rose Bengal staining was positive at epithelial defect margins. HSV DNA PCR, bacterial, and fungal cultures were negative. Diagnosis: graft infection—viral reactivation with superadded bacterial keratitis.

Treatment & Outcome

Started on hourly e/d vancomycin %, e/d tobramycin 1.3%, e/o Acivir 3% five times daily,e/d Homatropine 2% QID,e/d Prednisolone phosphate 1% BD, tab Acivir 400 mg five times daily for two weeks then two times a day, tab Doxycycline 100 mg BD, and tab Pantoprazole 40 mg OD.

By day 4, the defect and infiltrate reduced to 4 × 8 mm, leading to reduced antibiotic frequency. By day 8, defect decreased to 3.5 × 5 mm with infiltrate resolution.  concentrated antibiotics and Acivir ointment were stopped, and e/d moxifloxacin 0.5% TDS with lubricants was started. By day 14, the defect was 2.5 × 4.8 mm and fully healed by day 20, with vision improving to 6/18.

Herpetic keratitis should be considered in the differential diagnosis of both early- and late-onset post-keratoplasty epithelial defects, even in patients without a prior history of HSV infection. In cases where penetrating keratoplasty was performed without a known history of HSV, reactivation of latent HSV is the most likely cause. Clinical evaluation and imaging play a crucial role in diagnosis and management.