Diabetic Retinopathy—Update on Prevention Techniques, Present Therapies, and New Leads

Abstract

Diabetes is a metabolic disease resulting from the body's insufficient production or use of insulin, a peptide hormone responsible for regulating glucose levels in the blood and tissues. Especially when improperly managed, diabetes results in a number of complications over time, affecting nearly every organ system, including the ocular tissue. In addition to increased risk for glaucoma and cataracts, the most threatening ocular implication of diabetes is diabetic retinopathy, an aggressive disorder historically clinically associated with a variety of retinal microvascular abnormalities. Disease severity is typically classified into two types: nonproliferative diabetic retinopathy (NPDR), marked by microaneurysms, intraretinal hemorrhaging, and other microvascular aberrations, and proliferative diabetic retinopathy (PDR), characterized by the onset of neovascularization and vitreal hemorrhaging.1 Diabetic macular edema (DME), another manifestation of diabetic retinopathy involving macular thickening due to fluid accumulation, is accountable for a great proportion of diabetes-related vision loss. 2 While advanced stages of PDR have classically been regarded as the most threatening to sight, visual dysfunction at all stages, even those deemed mild by clinical evaluation, is now apparent. As the leading cause of blindness in US working-age adults, 3 diabetic retinopathy has many economic implications for healthcare systems and the overall population, 4 as well as a variety of personal consequences on patient quality of life. 5,6 However, if addressed early and proactively, the incidence of severe vision loss from diabetic retinopathy can be significantly reduced. This review will discuss the systemic measures necessary for diabetic retinopathy prevention, as well as interventions currently available to delay or stop retinopathy progression once diagnosed. The limitations of present treatment options will also be addressed, as well as current developments in the search for new endpoints and technologies that may allow for earlier detection.Finally, investigations of some of the new therapies and future approaches to diabetic retinopathy research will be reviewed. Systemic Control and Preventive InterventionAs the prevalence of diabetes worldwide continuously increases, incidence of vision-threatening diabetic retinopathy is projected to nearly triple in the next 40 years. 7 For patients diagnosed with diabetes, the most important method of preventing visual complications, such as retinopathy, is to control the diabetes at a systemic level. Tight regulation of glycemia via intensive insulin therapy significantly reduces the risk for retinopathy prevalence and progression. 8 In addition to its effect on glycemic and circulating insulin levels, systemic insulin therapy has been shown to have a local impact on ocular tissue as well, including restoration of retinal insulin receptor signaling cascade and rod photoreceptor function. 9,10We recently demonstrated that both components of systemic insulin treatment-normaliza...

German Diabetes Study – Baseline data of retinal layer thickness measured by SD‐OCT in early diabetes mellitus

“…; Dhamdhere et al. ; Marozas & Fort ). Being in line with these findings, it has been demonstrated that diabetic polyneuropathy may develop even in prediabetic stages (Ziegler et al.…”

“…Diabetic retinopathy (DR) is one of the major complications of diabetes mellitus (DM) and a leading cause of visual impairment and preventable blindness worldwide (Marozas & Fort ; Simó & Hernández ; Boegeberg Jonsson et al. ).…”

“…Neuronal alterations in the early course of disease are reflected by changes in retinal function. Animal trials and clinical studies revealed electroretinographic (Marozas & Fort ; Simó & Hernández ) and dark adaption alterations, visual field defects in short‐wave automated or frequency‐doubling perimetry as well as reduced contrast sensitivity and colour vision in early diabetes mellitus (Antonetti et al. ; Verma et al.…”

Heat shock protein‐70 and hypoxia inducible factor‐1α in type 2 diabetes mellitus patients complicated with retinopathy

“…Recent studies have explored and demonstrated the therapeutic potential of specific HSPs (Heise & Fort ; Athanasiou et al. ; Marozas & Fort ).…”

Common pathophysiology affecting diabetic retinopathy and Parkinson’s disease

“…Currently, combined control of glycemia, blood pressure, and serum lipid levels remains the most important strategy to prevent DR onset and progression. Once detected, ocular interventions including retinal laser photocoagulation, vitreoretinal surgery and intravitreal drug injection can help preserve vision [4].…”