Abstract
Abstract: :
Purpose: To study the biochemical effects of retinal laser injury in areas remote from direct laser exposure. Methods: 4-7 week old Sus scrofa pigs received retinal diode laser burns at varying time intervals between 0 and 24 hours using a precise time-to-fixation technique. Areas of timed retinal laser lesions were identified histologically and immunocytochemical staining for caspase-3, proliferating cell nuclear antigen (PCNA) and the Kenlow fragment of DNA polymerase was performed. Results: By 24 hours after laser injury, DNA damage is abundant in the outer retinal layers and decreases as a function of distance from the lesion center. The absence of activated caspase-3 positive cells and apoptotic morphology suggests that cellular necrosis predominates in the first 24 hours after laser injury. Similarly, there was no evidence of early cellular proliferation. Conclusion: Early in the course of a retinal laser lesion in the porcine model, DNA damage is present without evidence of apoptosis or retinal remodeling.
Keywords: 556 retina: neurochemistry • 537 radiation damage: light/UV • 554 retina