Very late-onset corneal scar triggered by trauma after photorefractive keratectomy.

A 54-year-old woman who had photorefractive keratectomy (PRK) more than 10 years earlier presented with a history of being hit in the eye by a tree branch and developing blurred vision a short time later. The corrected visual acuity was 20/100 with localized grade 3 stromal haze. The haze intensified despite initial response to corticosteroids and cyclosporine, and treatment with phototherapeutic keratectomy and 0.02% mitomycin-C (MMC) was effective in restoring corneal clarity and normal vision. Late-onset stromal scar can be triggered by trauma years after PRK. Phototherapeutic keratectomy with MMC can be an effective treatment for late-onset scar. Persistent haze or scar after trauma if PRK had not been performed previously is exceedingly rare.