Histopathological study on retinal lesions and restoration induced by micropulse diode laser and argon green laser in rabbits

Abstract

Objective To study the histopathological effect of retinal lesions and restoration induced by micropulse diode laser and argon laser in rabbits. Methods Under the parameter of diabetic macular edema micropulse diode laser and argon laser was used to produce retinal lesions in rabbit eyes. The histopathological alterations were observed. Results The subthreshold spots were undetectable and argon spots were detectable. The photoreceptor cells did not change but there was vascular engorgement in the choroid and it was disappear in 4 week after photocoagulation. The outer membranous discs were arranged disorder and the hydroncus of retinal pigment epithelial （RPE） and nodal cells was observed in argon spots by transmission electron microscope. The heterochromatin became muhy in outer nuclear layer. The hyperplasia of RPE and collagen were obviously in 4 week and the hyperplasia of pigment grains were seen in chorioid. But no changes were seen in micropulse spots. Conclusion The retinal lesions produced by micropulse diode laser were slightly than produced by argon laser. Key words: micropulse/laser; argon laser; retinal photocoagulation ; lesions ; rabbit