Diabetic Retinopathy is a disease resulting from the combination of three molecular mechanisms, as previously described. It should be mentioned that a rigorous control of blood glucose levels and blood pressure are fundamental to decelerate the progression of the disease. However, therapeutic treatments are imperatively needed to arrest the neovascular insult in the diabetic retina.
No available therapies exist to treat inflammation or neurodegeneration. Some of the therapeutic approaches utilized nowadays to combat the detrimental mechanisms around vascularization rely on laser photocoagulation in specifically affected areas in the retina (Mohamed et al., 2007). However, this therapy shows adverse effects reducing the vision quality. Other way to treat the deleterious effects of DR is the intravitreal administration of corticosteroids. Nonetheless, several sessions are needed leading to infections or even more serious side effects as cataract or glaucoma (Simó et al.
, 2009). There also are treatments for DME with anti-angiogenic agents such as: ranibizumab, bevacizumab, pegabtanib and aflibercept. They consist in the intraocular administration of monoclonal antibodies which inhibit the VEGF. The administration is usually expensive and despite showing side effects such as conjunctival haemorrhage, pain, increased intraocular pressure and inflammation, it seems to preserve vision much more than the laser does (Do et al., 2013). Seemingly, there are patients with better long-term visual outcome when using the combination treatment of laser and the administration of anti-angiogenic agents.
Vitreoretinal surgery is another treatment, though used for late stages of the disease, when the vision has already been significantly affected. This therapy is the most expensive, then not available to all DR patients (Joussen et al., 2007). In summary, most of the current therapies for DR require invasive procedures which may drive to retinal trauma putting at risk the remaining retina in good conditions. It has to be taken also into account that the anti-VEGF treatment may cause aggravating complications due to its ability to pass into the systemic circulation (Simó et al., 2008). Therefore, since the available treatments for DR have limitations, more research is essential to build new and more efficient strategies and identify new therapeutic targets to undermine the neurodegenerative and pro-inflammatory components of DR (Stitt et al.
, 2016). Moreover, these current pharmacological approaches are applicable at late stages of DR, when the retina has been highly damaged; ergo it is urgent to find preventable treatments in order to address the early stages of the disease. Thereby, Vasilaki et al. (2009) proposed a strategy to prevent retinal cell death with pharmacological agents with high efficacy and less side effects.
