Changes of MMP-9 expression in rabbit retina after laser irradiation at different thresholds

Abstract

AIM: To observe the changes of MMP-9 expression in rabbit retina after laser irradiation at different thresholds of 577nm.METHODS: Twenty-six pigmentation rabbits were randomly divided into normal control group(n=2), conventional photocoagulation group(n=6)and subliminal micropulse laser photocoagulation group(n=18). The conventional photocoagulation group was treated with 577nm laser photocoagulation, subcutaneous micro-pulsed laser photocoagulation at a working loading rate of 9%, 12% and 15%, respectively. Eighteen rabbits were again divided into three subgroups according different powers of subthreshold working loading rate of 9%(n=6), 12%(n=6)and 15%(n=6)that undertook, respectively. The expression of MMP-9 on the retina of rabbit eyes was detected by immunohistochemistry. RESULTS: In the conventional photocoagulation group, the expression of MMP-9 in the RPE layer and the visual cell layer was strongly positive, which was significantly higher than that in the sub-micro pulse group(PP>0.05).CONCLUSION: The 577nm subliminal micro-pulsed photocoagulation has high selectivity to retinal pigment epithelium at working load rate of 9%, 12% and 15%, and no damage to retinal nerve fiber layer, which is safer than conventional 577nm laser photocoagulation.

Keywords

• subthreshold micropulse laser
• retina
• MMP-9
• MMP-9