ABSTRACT
Retinal metabolism includes material metabolism and energetic metabolism.Retina is one of the most energy-consuming nerve tissue in human body and mainly relies on glycolysis for energy production, which is similar to very fast-growing tumor tissue.This process is known as Warburg effect.Warburg effect is of great significance, which is demonstrated that glucose is metabolized via glycolysis in a more rapid approach in comparison with oxidative phosphorylation pathway.In addition, glucose also supplies neoplastic tissue with carbon source or metabolic intermediates due to biosynthesis.The produced energy of retina is a summation of different retinal cells and tissue, such as photoreceptors, retinal pigment epithelium (RPE), Müller cells and retinal capillary endothelial cells etc.To understand the underlying mechanism contributing to Warburg effect and provide insight into metabolic coupling between neuron and glia is of important significance.Since key glycolysis enzymes (HK2, PFKFB3 and PKM2) take a pivotal role in controlling retinal cell proliferation and neovascularization, bioenergetic strategy targeting these enzymes suggests new idea in the treatment of retinal diseases where energy failure is part of the pathogenesis.Investigating underlying mechanism of retinal energy metabolism can provide new ideas for the treatment of age-related macular degeneration (AMD) and other diseases related to disordered retinal energy metabolism.The Warburg effect of retinal energetic metabolism and its regulatory mechanism were reviewed in this article.
ABSTRACT
Objective To evaluate the changes of the waveform of the photopic negative response in flash-electroretinogram, visual acuity and central retinal thickness in the treatment of intravitreal injections of bevacizumub. Design Retrospective self-comparative case series. Partidpants 8 subjects (9 eyes) with exudative age-related macular degeneration and 3 subjects (3eyes) with proliferative diabetic retinopathy. Method Evaluation protocol included examinations of the Early Treatment Diabetic Retinopathy study visual acu-ity, visual field, intraocular pressure, fundus fluorescein angiography, optical coherence tomography and flash-electroretinogram. Intravit-real injections of bevacizumab, 1.25 mg (0.05ml), were given under an operating microscope and aseptic conditions. All the subjects were followed-up one month later. Main outcome Measure The amplitudes of PhNR, visual acuity and central retinal thickness. Re-sult At 1 months, the mean amplitudes of PhNR and mean visual acuity in all cases had no obvious change (n=12, P>0.05).The central retinal thickness reduced obviously (n=12, P<0.05), but it was neither significantly correlated with PhNR (r=0.294, P=0.145) nor with visual acuity(r=-0.358, P=0.073). Conclusion The single intravitreal injection of bevacizumab is showed promising in absorption of in-traretinal edema and subretinal fluid in patients with exudative age-related macular degeneration and proliferative diabetic retinopathy, but the changes of visual function (including PhNR) might need further investigation. (Ophthalmol CHN, 2009, 18: 243-246)