Nutritional and medical food therapies for diabetic retinopathy

Abstract

Diabetic retinopathy (DR) is a form of microangiopathy. Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina. New approaches are needed, which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches. Homocysteine (Hcy) elevation and oxidative stress are potential therapeutic targets in DR.Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase (MTHFR), increase Hcy and DR risk and severity. Patients with DR have high incidences of deficiencies of crucial vitamins, minerals, and related compounds, which also lead to elevation of Hcy and oxidative stress. Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease. This approach provides safe and simple strategies that support conventional care and improve outcomes.Suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors. Collectively, this accounts for variability in presentation and response of DR to conventional therapy. Fortunately, there are straightforward recommendations for addressing these issues and supporting traditional treatment plans.We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity. Optimal combinations of vitamins B1, B2, B6, L-methylfolate, methylcobalamin (B12), C, D, natural vitamin E complex, lutein, zeaxanthin, alpha-lipoic acid, and n-acetylcysteine are identified for protecting the retina and choroid. Certain medical foods have been successfully used as therapy for retinopathy. Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR.DR from both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have similar retinal findings and responses to nutritional therapies.

Citicoline and Vitamin B12 Eye Drops in Type 1 Diabetes: Results of a 36-Month Pilot Study Evaluating Macular Electrophysiological Changes

“…We acknowledge that reducing oxidative stress is one of the potential therapeutic targets in DR, because patients with DM1 have a high incidence of deficiencies of crucial vitamins, minerals, and related compounds involved in the regulation of redox homeostasis. Therefore, reducing nutrient deficiencies may itself reduce the impact and severity of the disease [ 13 ]. Indeed, photoreceptors consume O 2 at very high rates compared with other cells of the organism and are thus exposed to a high degree of reactive oxygen species (ROS) generation [ 33 ].…”

“…We acknowledge that reducing oxidative stress is one of the potential therapeutic targets in DR, because patients with DM1 have a high incidence of deficiencies of crucial vitamins, minerals, and related compounds involved in the regulation of redox homeostasis. Therefore, reducing nutrient deficiencies may itself reduce the impact and severity of the disease [13]. Indeed, photoreceptors consume O 2 at very high rates compared with other cells of the organism and are thus exposed to a high degree The percentage of unmodified eyes (within the 95% confidence test-retest limit), eyes with improvement (values over the 95% confidence test-retest limit; solid line) and eyes with worsening (values under the 95% confidence test-retest limit; dashed line) are reported in Table 2 of reactive oxygen species (ROS) generation [33].…”

“…An important goal in NPDR can be to stabilize or reduce the retinal dysfunction detectable by psychophysical and/or electrophysiological methods. In this context, diet supplement interventions, based on medical nutrients that support conventional therapies, are known to reduce diabetes disease risk, severity, and complications, and in the case of DR to protect the retina and choroid [ 13 ].…”

“…Vitamin B 12 deficiency, instead, has a specific effect in promoting oxidative stress in DR and suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors [ 13 ].…”

Normal tension glaucoma: Prevalence, etiology and treatment

“…This is of importance because higher plasma levels of homocysteine are linked with an increased risk of vascular associated systemic diseases and eye diseases. The review of such nutritional therapies for treatment of diabetic retinopathy by Shi et al [25] gives the additional explanation of the utility of each component in the dietary supplement. Whether systemic L-methylfolate supplementation affects retinal perfusion must be studied in a larger population, but the utility of a single vitamin/mineral supplement to address nutritional defi ciencies in retinal vasculature would be a logical extension of treatments supported by the Age-Related Eye Disease Studies (AREDS) [25].…”