In-vivo response to free electron laser incision of the rabbit cornea

Background and Objective We analyzed the in vivo ocular response to corneal incisions made by Medical Free Electron Laser (MFEL) as a function of scan rate and incision depth. Additionally, we compared biomicroscopy, optical coherence tomography (OCT), and light microscopy as ocular response diagnostic tools. Study Design/Materials and Methods Rabbit corneas were incised with pulsed MFEL radiation at 2.94 μm wavelength, scalpel incisions or focal cautery treatment were used as controls. The MFEL beam scan rate ranged from 0.2 to 1.0 mm/second. Ocular effects were monitored for 2 hours postoperatively using OCT and slit lamp examination. Ocular tissue was fixed for light microscopic examination. Results Anterior chamber fibrin formation correlated with MFEL incision depth. Slower scan rates resulted in deeper incisions and greater fibrin formation. OCT was better than slit lamp biomicroscopy at identifying fibrin attachments. OCT and light microscopy proved to be excellent companion technologies. Conclusions Deep corneal incisions in the rabbit produced by the MFEL resulted in fibrin formation in the anterior chamber. Lasers Surg. Med. 29:44–52, 2001. © 2001 Wiley‐Liss, Inc.