In the news: Ocular Blood Flow & Glaucoma Progression Vitamin E May Help Fight Fatty Liver Disease

Ocular Blood Flow & Glaucoma Progression

Compromised ocular blood flow has been established as a contributing factor in the onset and development of open-angle glaucoma (OAG). Lacking, however, are larger, long-terms studies investigating whether ocular blood flow biomarkers are predictive of disease progression.

A newly published study(1) now suggests that specific retinal capillary blood flow biomarkers may predict glaucoma progression after five years.

Researchers evaluated 112 early to moderate OAG patients at baseline and every 6 months for 5 years. Biomarkers of retinal capillary blood flow were assessed by Heidelberg retinal flowmetry. Functional changes were monitored by Humphrey Visual Field exams. Structural progression, reflected by decreases in retinal nerve fiber layer thickness and/or increases in cup to disc ratio, was tracked with OCT and Heidelberg retinal tomograph.

The results showed that lower retinal capillary blood flow in the superior retina was significantly associated with structural progression (p = 0.0009).

In this study structural and functional progression occurred even with lowered IOP over 5 years, confirming that glaucoma can progress in many patients despite well-controlled IOP.

Future research should focus on identifying and translating vascular insufficiency into actionable targets of research and clinical care in glaucoma, according to the authors. One research direction has attempted to identify neuroprotection measures. Certain antioxidants, for example, have been shown to increase biomarkers of ocular blood flow including superior retinal capillary blood flow(2).

Vitamin E Useful in Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), a build-up of fat in the liver, is the most common liver problem in the US. About 25% of adults are estimated to have the condition, and rates have been steadily climbing over the past three decades. About 20% of those with NAFLD progress to NASH (or nonalcoholic steatohepatitis). NASH in turn may lead to cirrhosis or even liver cancer.

NAFLD has recently undergone a name change to Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD). The name now emphasizes the metabolic origins of the condition, as certain genes and metabolic disorders such as obesity, diabetes and high blood pressure raise the risk for MASLD.

The first line of treatment for MASLD and NASH is weight loss through calorie restriction, exercise and healthy eating. According to the results of a recent meta-analysis(3), vitamin E may also compliment these lifestyle changes.

The meta-analysis of 12 randomized controlled trials looked at the effect of vitamin E supplementation on blood levels of the liver enzymes alanine aminotransferase (ALT) and aspartate amino-transferase (AST) in 794 adults and children with MASLD / NASH. Elevated levels of these liver enzymes are associated with MASLD / NASH.

In 7 of the trials, vitamin E was accompanied by lifestyle modification in both vitamin E and placebo groups. The trials ranged from 4 to 96 weeks in length.

Vitamin E, ranging from 400 to 800 IU daily, consistently reduced serum ALT (-13.06 IU/L) and AST (-6.00 IU/L) levels compared with a placebo.

The beneficial effect of vitamin E seemed to be independent of ethnicity, whether the participants were adults or children, whether or not vitamin E was combined with interventions to improve overall dietary intake and increase physical activity, or whether the duration of the trials was less than 24 weeks or 48 weeks or more.

References

1. Vercellin AC, Harris A, et al. Ocular blood flow biomarkers may predict long-term glaucoma progression. BJO. [Epub ahead of print] Oct 18, 2023.
2. Harris A, et al. The effects of antioxidants on ocular blood flow in patients with glaucoma. Acta Ophthalmol. 2017.
3. Vogli S, et al. The effect of vitamin E supplementation on serum aminotransferases in non-alcoholic fatty liver disease (NAFLD): A systematic review and meta-analysis. Nutrients. 15(17)3733, 2023.