Inflammation induced by photocoagulation laser is minimized by copper chelators

Abstract

The effect of trientine hydrochloride (TRIEN), a copper-selective chelating agent, on retinal inflammation induced by photocoagulation laser treatment was studied. Nine Long-Evans rats were treated with TRIEN (0.5 mmol/kg per day, intraperitoneal injection) for 9 days. On day 8, each animal underwent unilateral photocoagulation laser treatment with an argon dye laser. On day 9, animals were killed and the eyes processed for immunohistochemistry and light microscopy. In the TRIEN-treated group, retinal thickness and number of macrophages (ED-1) were both significantly lower than in the saline-treated, control group exposed to laser photocoagulation. The results support the hypothesis that selective copper chelation prior to laser treatment may inhibit ocular inflammation. The results suggest that pretreatment with a selective copper-chelating compound can minimize retinal inflammation secondary to laser photocoagulation treatment, which may improve overall outcome of photocoagulation treatment for diabetic retinopathy.

Effects of intravitreal triamcinolone acetonide on retinal gene expression in a rat model of central retinal vein occlusion

“…Therefore, only tissues from animals, in which CRVO was confirmed in fluorescein angiography before the animals were killed, were used for the PCR analyses. A further limitation of the model is that laser photocoagulation induces retinal inflammation [24], which is not observed in the clinical setting. Thus, in addition to the effects of CRVO-induced hypoxia, laser-induced inflammation may contribute to the alterations in the retinal gene expression observed in the present study, and the effects of triamcinolone might in part mediated by the antiinflammatory action of the agent.…”

Copper induces – and copper chelation by tetrathiomolybdate inhibits – endothelial activationin vitro

“…20,21 As a redox-active transition metal, copper can act as an electron carrier to catalyze the generation of ROS, potentiating oxidative stress and inducing inflammation. 22,23 Copper has been implicated either directly or indirectly in atherosclerosis 24 and has been shown to stimulate atherosclerotic lesion formation in rats by inducing vascular inflammation. 25 Moreover, copper deficiency downregulates inflammatory cytokine expression in mice.…”

Structural and functional changes to the retina and optic nerve following panretinal photocoagulation over a 2-year time period

“…27 ROS generates an immune response in the retinal tissue by increasing the intraretinal junctional permeability and recruitment of leukocytes. 7,[27][28][29][30][31] The decrease post 6 months suggests that the effects of an acute inflammation persist up to 6 months in the retinal tissue after laser treatment. Overall, by 24 months, there is no significant change in the macular or RNFL thickness compared to pretreatment state.…”