SAFFRON AND GLAUCOMA

 

Introduction

Abnormal resistance to the outflow of aqueous humor through the trabecular meshwork (TM) is a key factor in the pathogenesis of primary open angle glaucoma (POAG).

Oxidative stress plays a role in the development of POAG by causing changes in the TM.

Saffron is derived from the pistils of Crocus sativus.

It contains high concentration of crocin and crocetin (carotenoid derivatives).

Saffron is a powerful radical scavenging, antioxidant and antitumor agent.

In a study performed in Iran, it has been shown that high doses of oral saffron extract can reduce intra-ocular pressure (IOP).

The saffron study

The above mentioned study was performed at the 22nd of Bahman Hospital, Gonabad, Iran.

Inclusion criteria were set as: Patients with POAG older than 50 years of age being treated with timolol 0.5% BD and Dorzolamide 2% TID, judged to have stable glaucoma control for atleast 6 months, based on a series of visual field and optic nerve head examinations.

34 patients were randomized to receive either saffron extract or placebo.

The study was kept double blinded from patients, ophthalmologists and statisticians.

Crocus sativus stigmas were collected from Gonabad. Using the maceration technique saffron capsules containing 30 mg of concentrated powder was prepared. Starch powder capsules were used for placebo.

Subjects were randomly assigned to oral saffron (30mg per day) or oral starch capsules for one month, while continuing the topical medications.

At the end of the study all patients entered a one month washout period when saffron was stopped while continuing the topical medications.

Results: Mean baseline IOP was 12.9+/- 3.7 (7-19) mmHg in the saffron group and 14+/-2.5 (9-18) mmHg in the control group.

One week after intervention, IOP was 12+/-3.3 mmHg in saffron group vs. 13.6+/-2.6 mmHg in the control group. At four weeks IOP was 10.6+/-3 (6-16) mmHg in saffron group vs. 13.8+/-2.2 mmHg in control group. At the end of the washout period IOP was 12.9+/-3 (8-18) mmHg in saffron group and 14.2+/-2.0 in the control group.

Discussion

Antioxidants are beneficial in reducing the risk of multiple ocular diseases including AMD.

Oxidative stress is also implicated in the development and progression of POAG.

The trabecular meshwork is especially sensitive to oxidative stress.

Light-induced formation of oxidative radicals may target the TM and contribute to the pathogenesis of glaucoma.

Disturbed cell homeostasis from oxidative stress may lead to cellular loss and structural alterations in it's extracellular matrix, resulting in impaired aqueous humor outflow and thereby an increase in IOP.

Saffron has the ability to reduce IOP, but it may also have antioxidant-neuroprotective properties.

Antioxidants exert a short term effect by rehabilitating damaged but still functional TM, and a long-term benefit by reducing apoptosis.

The ocular hypotensive effect shown by saffron extract can be attributed to short term effect.

Safety

Saffron has low toxicity and doses upto 1.5gm are regarded as safe.

The colored constituents of saffron may accumulate in sclera, skin and other tissues to mimic icteric features.

Nausea, vomiting, diarrhea is reported in doses around 1.5-2gm.

Conclusion

 Saffron may prove to be a safe and effective hypotensive agent with additional antioxidant-neuroprotective properties.