Extended Dehydration of Corneal Allogenic Intrastromal Ring Segments to Facilitate Insertion: The Corneal Jerky Technique

Abstract

Purpose: The aim of this study was to describe a new technique to facilitate the insertion of corneal allogenic intrastromal ring segments. Methods: A single-segment corneal allogenic intrastromal ring segment (CAIRS) was trephined from donor corneas and allowed to markedly dehydrate for 75 minutes before the start of the procedure with a room humidity of 35% to 45%. The duration of the insertion step and the intrastromal segment size at 1 week as measured by optical coherence tomography were compared with previously performed single-segment CAIRS procedures using the conventional technique. Results: A total of 41 eyes of 36 patients underwent 1-segment CAIRS insertion of the same trephination size (750 µm). Fifteen eyes underwent the conventional insertion procedure, and 26 eyes had a dehydrated segment inserted. The time taken to insert the CAIRS analyzed by surgical video recording starting after the femtosecond tunnel creation and initiation of the insertion to the segment ironing step was 282 ± 103 and 97 ± 23 seconds for the conventional and the dehydrated segment technique, respectively (P < 0.001). Anterior segment optical coherence tomography performed 1 week postoperatively revealed similar segment thickness and width of 471.3 ± 54.1 μm and 1285.1 ± 191.0 μm for the conventional allogenic segments and 483.4 ± 58.3 μm and 1227.2 ± 165.2 μm for the dehydrated segments (P = 0.515 and 0.314, respectively). Conclusions: Markedly dehydrated corneal allogenic segments are easier and faster to insert than the nondehydrated ones while maintaining similar sizes intrastromally. This dehydration technique makes the procedure similar to the one with synthetic segments and hence reduces the learning curve.