In the news: Can Saffron Play a Useful Role In Glaucoma Management?

Could Saffron Be of Benefit in Glaucoma?

There is consensus that oxidative stress plays an important role in the progress of primary open-angle glaucoma (POAG) and may be an appropriate therapeutic target.

Oxidative stress induces mitochondrial DNA damage, and the release of factors associated with apoptosis or programmed cell death. Studies have consistently shown elevated levels of oxidative stress markers and a decrease in antioxidant defenses in the eyes of glaucoma patients.

The antioxidant, anti-inflammatory and neuroprotective properties of saffron have stimulated research into the herb’s effect in ocular conditions. It has been reported to have a protective effect on the retina in diabetic maculopathy, and to improve vision-related outcomes in age-related macular degeneration – outcomes such as such as multifocal electro-retinography that assesses retinal function.

In addition to oxidative stress, saffron components may be protective via promoting ocular blood flow. Crocin, a saffron bioactive, has been reported to improve blood flow of the retina and the choroid. Ischemia or poor blood supply to ocular tissues can cause hypoxia, a condition associated with neurodegeneration in glaucoma.

The active ingredients, crocin and crocetin are found in the stigmas of saffron (Crocus sativus). Both compounds are carotenoid pigments that differ in their chemical structure and how they are absorbed by the body. Crocin is a glycosylated form of crocetin, meaning it has sugar molecules attached while crocetin is the aglycone (non-sugar) form. Crocin is largely metabolized to crocetin in the gastrointestinal tract before absorption.

Previous clinical findings led researchers to evaluate the potential effects of supplemental crocin in managing POAG(1). In total, 50 patients aged 30-71 with stable POAG and intraocular pressure (IOP) between 12-21 mmHg were enrolled, and 40 patients (49 eyes) finished the trial.

Participants were randomly assigned to take a tablet with 15 mg. crocin daily, or to receive a placebo, along with topical medications. After four months, all patients underwent a two-month washout period.

IOP, the primary outcome, as well as OCT of the retinal nerve fiber layer (RNFL), cup to disc ratio (CDR) and best corrected visual acuity (BCVA) as secondary outcomes were measured at baseline, and at four and six months.

After four and six months, IOP fell significantly within the crocin group (p= 00001 and p= 0.003 respectively). In contrast, there was no significant change in IOP within in the placebo group at either time point.

The difference in IOP change was significant between the crocin and placebo groups at 4 months (p= 0.0001) and at the 6-month mark (p= 0.001).

The difference in CDR changes after four and six months was also significant between the two groups (p = 0.0009). According to the authors, the CDR data indicates that the crocin group experienced a stable neural condition during the trial while the placebo group saw an increase in CDR values.

There was no significant difference between the groups regarding the changes in BCVA and RFNL thickness.

Additionally, there were no differences between the groups in terms of reported side effects. The authors point out that several previous studies have confirmed the safety of daily consumption of crocin.

The results of this pilot clinical trial suggest that crocin may be of use in POAG patients, though further research is needed.

References

1. Mahdiani S, et al. Crocin supplementation in primary open angle glaucoma: A randomized, triple-blind, placebo-controlled clinical trial. Med Drug Discovery. Vol 21:100169, 2024.