Abstract
Abstract: :
Purpose: The early, time-dependent bioeffects of laser retinal injury are unknown. We devised a novel method to produce precisely timed laser lesions at controlled intervals prior to fixation. Methods: Ten 4-7 week old Sus scrofa pigs received retinal laser burns at varying time intervals. Long-term lesions (24-72 hours) were applied using an indirect diode laser. In the same eye, short-term lesions were applied using an endolaser probe after vitrectomy, lensectomy and fluid air exchange. Five linear laser lesions spaced approximately 1 mm apart (200-250mW, 2 seconds duration) were applied within the vascular arcades at 20, 15, 10, 5 minute intervals. A final, «time 0» laser burn was applied and the entire interior of the globe was infused instantly with 4% formalin through a separate pars plana sclerostomy port. The surgeon used a systematic methods of documenting were each laser stripe was made and a diagram of the retinal atomy accompanied each specimen. The eyes were enuclated and placed in formalin, sectioned, and embedded within 24 hours. Results: In all ten animals, the laser injuries were reproducible without complications and a masked histopathologist easily identified each laser lesion. Conclusion: This technique allows the creation of a chronological record of retinal laser burns ranging from 0-72 hours in a single histologic specimen. In this way, the earliest biochemical effects of laser injury can be studied.
Keywords: 454 laser • 316 animal model • 554 retina