Clinico-pathological correlation of patients undergoing keratoplasty for suspected HSV keratitis in tertiary care centre

Aim: To identify histopathologic features of HSV keratitis and correlate them to their clinical findings following penetrating keratoplasty for suspected HSV keratitis and predict the graft outcome on oral Acyclovir treatment. Material and methods: A clinical study of 20 patients who presented to us with clinical picture suspected of HSV keratitis that underwent penetrating keratoplasty at a teaching hospital situated in rural area of India. Out of 20 patients 18 were primary grafts and in 2 patients repeat penetrating keratoplasty was done following graft failure due to rejection. A detailed review of the histopathology of the excised corneal button was performed to identify associations between clinical data (disease activity, vascularity, graft outcome) and histopathologic data (inflammation, neovascularization, gross). Patients with features of HSV keratitis on histopathology were started on oral prophylactic acyclovir therapy post penetrating keratoplasty. Results: All patients had clinically quiescent disease for at least 6 months before surgery. The visual outcome was better in 14 patients on oral acyclovir post penetrating keratoplasty in suspected HSV keratitis positive on histopathology including 2 repeat keratoplasty which were not earlier started on oral acyclovir. Histopathology of 12 cases including 2 repeat Penetrating keratoplasty revealed active corneal inflammation with epithelial irregularities along with patchy loss of Bowman’s membrane, infiltration of anterior stroma by lymphocytes, leukocytes and plasma cells. Diffuse fibrosis and neovascularisation of stroma was present which was correlated clinically. No recurrence was seen in these patients on follow up of 1 year. Of the 6 patients without any histopathologic inflammation in their corneas, only 1 experienced an allograft rejection. Conclusion: Histopathological inflammation is a marker for HSV status and its correlation helps in judicious use of acyclovir and reduces the risk of recurrence of HSV keratitis. Oral acyclovir therapy post penetrating keratoplasty acts as adjunct to improve the visual outcome in patients with positive histopathological changes.