Rapid Dehydration of Corneal Allogeneic Intrastromal Ring Segments (CAIRSs) by Thermal Energy Conduction and Heating to Facilitate Implantation

Purpose: The purpose of this study was to describe a new technique for rapid extensive dehydration of corneal allogeneic intrastromal ring segments (CAIRSs) using thermal energy conduction to facilitate implantation. Methods: Donor corneas were trephined into annular stromal rings, halved, and placed into a titanium mold with a semicircular recess. The mold was positioned on a sterile polyethylene drape covering a USB-powered cup heater with a tempered glass surface (Tangxi, Guangzhou, China, set to 55°C). Segments were covered with a 1 oz plastic medicine cup (Amsino International, Pomona, CA) for 5 minutes, after which their temperature was monitored using a laser thermometer and found to be 47.5 ± 0.8°C. Resulting segments were rigid and maintained their arc shape, allowing for forceps-only insertion into femtosecond laser-created stromal tunnels. Insertion time (from tunnel creation to segment ironing) was measured through surgical video. Segment dimensions were assessed using optical coherence tomography at 1 week, 1 month, and 3 months. Four dehydrated segments underwent histopathologic analysis. Results: A total of 33 eyes from 29 patients underwent single-segment CAIRS implantation using the thermal dehydration technique. The mean combined insertion and repositioning time was 86 ± 19 seconds. Optical coherence tomography showed segment thickness and width of 498 ± 72 μm and 1119 ± 175 μm at 1 week, and 443 ± 67 μm and 1292 ± 220 μm at 3 months. Histopathology revealed preserved stromal architecture without evidence of thermal damage. Conclusions: Controlled thermal energy conduction significantly reduces CAIRS dehydration time and simplifies insertion, enhancing surgical efficiency while preserving tissue integrity.