Sterile Inflammatory Reaction Mimicking Endophthalmitis After Prk - Case Presentation

To report a rare case of severe sterile inflammatory response following photorefractive keratectomy (PRK) that mimicked infectious endophthalmitis.

The patient was initially treated at a private refractive surgery clinic and subsequently referred to the Department of Ophthalmology, Carmel Medical Center, Haifa, Israel. 

Case report of a 19-year-old immunocompetent female who developed acute-onset ocular pain and decreased vision 72 hours after undergoing uncomplicated PRK for low myopia (-2.00D with minimal astigmatism) in the left eye. Comprehensive ophthalmic evaluation was performed, including anterior segment optical coherence tomography (AS-OCT), and ocular ultrasonography. Extensive microbiological workup comprised corneal scrapings for Gram stain, bacterial/fungal cultures, and multiplex PCR for detection of bacterial, viral, and fungal pathogens.

Upon presentation, visual acuity of hand motion. Slit-lamp examination showed diffuse central corneal infiltrate with indistinct margins, pigmentary keratic precipitates, and 0.5mm hypopyon, normal intraocular pressure. AS-OCT showed stromal thickening and endothelial irregularities. All microbiological tests were negative, suggesting sterile marginal hypersensitivity (SMH) as a possible cause. Treatment included intensive topical steroids, fortified antibiotics, antibiotic ointment, and systemic therapy (prednisone, doxycycline, ascorbate). Marked improvement noted with complete hypopyon resolution within 72 hours. By day 5, best-corrected visual acuity improved to 6/12, with mild corneal haze, minimal edema, and reduced Descemet's folds.

This case highlights the diagnostic and therapeutic challenges in distinguishing sterile inflammation, likely caused by sterile marginal hypersensitivity (SMH), from infectious keratitis or endophthalmitis after PRK. Effective management involves prompt anti-inflammatory therapy with prophylactic antimicrobials, preserving visual outcomes despite the alarming presentation.