Effect of dietary omega‐3 and omega‐6 fatty acids on IOP elevation, electroretinographic changes and retinal ganglion cell loss in a rat model of glaucoma induced by laser

Abstract

Abstract Purpose To test the efficacy of dietary omega‐3 and omega‐6 fatty acids in a rat model of glaucoma induced by laser photocoagulation. Methods Rats were fed for 3 months with a diet containing either: 1) 17% of omega‐3 fatty acids (10% EPA + 7% DHA), 2) 10% of omega‐6 fatty acids (as GLA), or 3) a combination of both omega‐3 and omega‐6 fatty acids (10% EPA + 7% DHA + 10% GLA), by comparison with a control group of animals fed with a standard diet deprived of EPA, DHA and GLA. After 3 months of diet, glaucoma was induced in one eye of the animal by laser.IOP was regularly measured and the retinal function was evaluated by electroretinography (ERG) for 3 months. At the end of the experiment, the loss of the retinal ganglion cells in both operated and fellow eyes was evaluated after retrolabelling using Fluorogold. Results A significant increase of IOP was observed in the laser treated‐eyes: 49±16 mmHg compared to 11±1.2 mmHg in the fellow eyes, after photocoagulation. IOP elevation was similar in each group. The ERG b‐wave amplitude was significantly reduced by approximately 70% 8 and 12 weeks in the laser treated‐eyes.None of the diets efficiently prevented the loss of the retinal ganglion cells. Conclusion Neither dietary omega‐6 nor omega‐3 fatty acids efficiently prevented the development of glaucoma in our rat model, as illustrated by the absence of effects against IOP elevation and loss of retinal ganglion cells. Further works are warranted to elucidate the mechanisms and consequences of the effects of omega‐6 fatty acids on the retinal function as assessed by ERG.