Freeze-dried versus cryopreserved amniotic membranes in corneal ulcers treated by overlay transplantation: a case-control study.

Abstract

Purpose : To assess cryopreserved (C-AM) versus sterilized chorion-free freeze-dried (FD-AM) amniotic membranes overlay transplantation for corneal epithelial defects in a French tertiary ophthalmology hospital

Methods : Between March and July 2020, when C-AM were not available due to the COVID-19 pandemic and to the national lockdown, 28 corneal ulcers underwent FD-AM overlay transplantation and were retrospectively compared to 22 corneal ulcers treated with C-AM during the same period in 2018. All patients had at least 3 months of follow-up and those who underwent combined surgeries were excluded. Ulcers were assessed at baseline and then at 1 and 3 months. Population demographics, follow-up time, ulcer etiologies, ulcer size, and complications were also recorded.

Results : Baseline characteristics and clinical features of both groups were comparable. There was no statistically significant difference in the number of overlay amniotic membrane transplantations (p= 0.52) or early fall (p=0.57). At 3 months, the corneal healing rate was almost the same in both groups (89% and 91% for FD-AM and C-AM, respectively; p=0.85). Complications were evenly unusual (11% and 9% respectively; p=0.92). In logistic regression, the nature of the membrane did not influence corneal healing at 1 month (p=0.42) and 3 months (p=0.99) regardless of the depth of the ulcer. However, whatever the type of AM used, the deeper the ulcer was, the less likely it was to heal at 3 months (p=0.02).

Conclusions : This first study provides positive insight into the effectiveness of FD-AM as compared to C-AM when used as overlay transplantation for treating corneal ulcers.

This is a 2021 ARVO Annual Meeting abstract.