Pre-loaded donor corneal lenticules in a new validated 3D printed smart storage glide for Descemet Stripping Automated Endothelial Keratoplasty

Abstract

Purpose: To design and validate the efficacy of a 3D printed smart storage glide (SSG) capable to preserve and deliver posterior lenticules for Descemet Stripping Automated Endothelial Keratoplasty (DSAEK).

Methods: Laboratory investigation and prospective interventional case series conducted at The Veneto Eye Bank Foundation and Villa Igea Hospital, Italy. Unsuitable corneas for transplantation [n=20] were used for laboratory investigation. These tissues were cut using a standard microkeratome, punched and loaded into the SSG and preserved for 7 days in transport media. Endothelial cell density (ECD), mortality using Trypan blue staining, cell apoptosis using TdT dNTP kit, immunostaining using ZO-1 marker, thickness measurements and glucose uptake post-preservation were analyzed. Clinical grade corneas [n=14] were pre-loaded in SSG and grafted in patients by one surgeon (MB) with indications of Fuchs’ dystrophy (n=8), pseudophakic bullous keratopathy (n=3), posterior polymorphous dystrophy (n=2), and previous DSAEK failure (n=1). In all cases a standardized DSAEK was performed, including descemetorhexis under air and bimanual delivery of the tissue under infusion of BSS through an anterior chamber maintainer placed at the 12o’clock position. Main outcome measures were surgical time, best spectacle-corrected visual acuity (BSCVA), speed of visual recovery, and ECD.

Results: Average ECD loss was 2.30(±3.21)%, thickness increased by 30.80(±20.85)% and 1/3rd of glucose was utilized during the preservation phase of the laboratory study. Cell apoptosis was not observed whereas expression of tight junctional protein (ZO-1) was observed on the preserved tissues. ECD of donor tissue before surgery was 2740±91cells/mm², mean ECD post 6 months was 2040±297cells/mm² with 25% ECD loss. BSCVA improved to 20/25 or better in all cases within 3 months after DSAEK. Mean surgical time recorded was 21 minutes.

Conclusions: The study describes the development, design, laboratory and clinical validation of a 3D printed SSG which helps to store and deliver posterior lenticules therefore allowing transportation of pre-cut tissues. This may facilitate faster, easier and more reliable DSAEK surgery with quality control and reduced wastage of utilized tissue.