Herpes keratitis after corneal trauma - A possible occupational disease?

Background: Herpes simplex virus (HSV) keratitis is among the most common causes of infectious corneal disease and encompasses epithelial, stromal and endothelial disease processes. Different trigger factors are commonly thought to be associated with recurrences of HSV keratitis but, in spite of its high prevalence, the exact mechanisms for the recurring nature of HSV keratitis are unclear. Ophthalmologists therefore face difficulties when asked to assess the relation between ocular trauma and subsequent herpetic eye disease. Case Report: At the age of 21, a man developed stromal herpetic keratitis of his right eye. Ten years later, he experienced a superficial corneal injury of the same eye with a metal foreign body during work. Subsequently, severe stromal keratitis with multiple recurrences developed. Due to progressive endothelial decompensation, a perforating keratoplasty was performed at the age of 51. Six years thereafter, re-keratoplasty became necessary because of a fungal keratitis of the transplant. The patient was convinced that the initial occupational corneal injury was the cause of the following recurrences of HSV keratitis and therefore was responsible for the resulting reduction of visual acuity. He thus filed an action for receiving an invalidity pension. Results: The different possible pathophysiological situations at the time of induction of a traumatic herpetic keratitis are presented and discussed. General guidelines for the assessment of traumatic herpetic keratitis are suggested. Conclusions: Patients who have suffered from one or more previous episodes of HSV keratitis are at a high risk for recurrences. In the depicted case, stromal keratitis had already occurred once before the trauma. The recurrences of herpetic keratitis following the injury therefore could not be attributed to the trauma with sufficient probability.