Retina remodeling following diode laser.

Abstract

BACKGROUND: The purpose of this study was to characterize the sequential development of focal and surround retinal injury and repair following transscleral diode laser to rat retina. METHODS: Transscleral laser photocoagulation of the retina was induced with a diode laser (DioPexy Probe, 810 nm, 200 mW, 2 seconds) in adult Long-Evans rats. The right eye of rats with survival times of 0 days (n = 4), 5 days (n = 6), 2 weeks (n = 4), 6 weeks (n = 6), and 12 weeks (n = 4) was studied. Using serial sections, detailed pathological changes in laser-treated and surrounding retinal and choroidal areas were compared with the control fellow eye. RESULTS: Photocoagulation damage was limited to the retina, sparing Bruch's membrane, with minimal choroidal involvement in almost all cases (23/24 eyes). Following damage to the neural retina, the sequence of major remodeling processes was consistent and included inflammatory response, reparative changes, and formation of glial-vascular scar with neovascularization. INTERPRETATION: This new laser model caused reproducible injury, inflammation, and scarring confined to the retina, and may be a tool to help test the effects of candidate neuroprotective/regenerative agents on retinal degeneration to prevent vision loss.