Amniotic membrane transplantation for persistent corneal epithelial defects in eyes after penetrating keratoplasty

Purpose To determine the primary success and recurrence rate of amniotic membrane transplantation (AMT) for the treatment of persistent corneal epithelial defects (PEDs) in eyes after penetrating keratoplasty (PK). Design Retrospective, non-randomized, observational case series. Method AMT was performed in 24 eyes of 24 patients with erosions (n = 6) or ulcers (n 18), which were resistant to medical therapy. All eyes had undergone one (42%) or more PKs before AMT. After the removal of epithelium and pannus (if present), one or more layers of AM ('graft' (n = 3), 'patch' (n = 5), 'sandwich' = combination of graft/patch (n 16)) were transplanted. Main outcome measures included 'surgical success' (epithelium closed within 4 weeks after AMT), and 'recurrence' (new epithelial defect developing during follow-up after surgical success). Results The rate of surgical success was 70% and was found to be inversely proportional to the number of previous PKs. Defects limited only to the centre of the graft had a higher success rate (central: 100%, non-central: 61%). A total of 44% successful eyes (erosions: 75% vs ulcers: 33%) had a recurrence after a mean follow-up of 16 +/- 13 months. The rate of surgical success was highest (81 vs 67 vs 25%) and the rate of recurrence was lowest (38 vs 90 vs 100%) with the sandwich technique in contrast to the graft or patch techniques used alone. Conclusions AMT may be beneficial in the treatment of PEDs after PK, especially when applying the sandwich technique. Recurrences seem to be more frequent, if PK preceded AMT.