Palmitoylethanolamide (PEA) as a Treatment of Normal Tension Glaucoma
People with Normal Tension Glaucoma (NTG) may have “normal” or high normal IOP yet still develop nerve damage. Although the cause of Normal Tension Glaucoma is unknown, a number of risk factors have been discovered including:
- Systemic hypotension (low blood pressure)
- Cardiovascular (heart) disease
- Conditions including migraine and Raynaud’s disease
- Defective vascular autoregulation
- Autoimmune disease
- Hemorheologic (blood “thickening”) abnormalities
- Cerebral microvascular ischemia
As with the more common forms of glaucoma, Normal Tension Glaucoma is treated by lowering the intraocular pressure (IOP). As you might surmise, however, this can be a challenge when the IOP is already in the “normal” range. Eye drops, laser therapies, and many of the lower-risk surgical treatments simply don’t work as well at lowering the IOP when it is already within the physiologic range. As such, many patients with Normal Tension Glaucoma end up requiring trabeculectomy surgery in order to slow vision loss.
The supplement Ginkgo biloba has been studied as a potential treatment of Normal Tension Glaucoma. Unfortunately, due to its blood thinning properties, it may not be safe for those already taking prescription blood thinners to also take Ginkgo biloba. Fortunately, it appears that Ginkgo biloba may not be the only natural supplement with a potential role in the treatment of Normal Tension Glaucoma.
What it is Palmitoylethanolamide (PEA)?
Palmitoylethanolamide (PEA) is a naturally occurring substance that mimics chemicals known as endocannabinoids. Our bodies naturally produce PEA. Certain foods such as peanut oil, egg yolk, and soybean lecithin also contain PEA. If the term “endocannabinoid” sounds familiar it is because “cannabis” is the term used to describe plants that produce delta-9-tetrahydrocannabinol (the main active ingredient in marijuana). There is evidence that cannabinoids can be used to treat glaucoma. What about PEA?
Evidence that PEA can be used to Treat Normal Tension Glaucoma (NTG)
PEA has been shown to increase the flow of aqueous fluid out of the eye. Additionally, PEA is naturally found in the ciliary body (the eye tissue that produces aqueous fluid). In patients with glaucoma there is a reduced amount of PEA in the ciliary body. If patients with glaucoma have a decreased amount of PEA in their eyes could increasing the amount of PEA treat glaucoma?
The answer appears to be “yes”. An Italian study evaluated the effect of taking 300mg of PEA twice daily over a six month period. Patients with Normal Tension Glaucoma were randomized into treatment or no treatment (it would have been a more convincing study had there been a placebo control). Those patients who received PEA experienced both lower IOP (average 14.4mmHg -> 11.1mmHg) and visual field improvement.
Potential Side Effects and Risks of PEA
No serious ocular or systemic side effects have been noted at a dose of 300mg taken twice daily.
Potential Drug Interaction
No known drug interactions.
In the above mentioned study patients were instructed to take 300mg of PEA by mouth twice daily (after breakfast and dinner).
Where to Buy
PEA is not cheap. The purest commercially available form (PeaPureTM) is $30-50 for a package of 30 (thirty) 400mg capsules. I am aware of only one US reseller who currently stocks PeaPureTM: FitEyes.
The formulation used in the Normal Tension Glaucoma study referenced earlier was Visimast® 300mg (taken twice daily). Although commonly available in Italy, Visimast® is not commercially available in the USA. Of the Italian pharmacies that are willing to ship Visimast® to the USA, the quoted delivery fees alone can be upwards of $100. So, unless someone is purchasing a year’s supply, this would not be a very economical option.
Regardless of the form of PEA taken, the expected monthly cost of this treatment would be in the range of $45-100 USD.
Because the IOP is in the normal range, those with Normal Tension Glaucoma are often diagnosed late in the disease after significant vision loss has occurred. Even when diagnosed early, Normal Tension Glaucoma tends to be one of the more challenging forms of glaucoma to control with standard lower-risk therapies. The only other supplement with decent evidence of benefit in those with Normal Tension Glaucoma, Ginkgo biloba, cannot be safely taken in those who are also on prescription blood thinners. PEA, on the other hand, has no known serious side effects or drug interactions. Thus, I currently recommend that my patients with Normal Tension Glaucoma who can afford to do so take 300mg of PEA twice daily.
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Don’t delay getting checked for glaucoma.
Make an appointment with an eye doctor in your area now. If you live in the greater Los Angeles area and would like Dr. Richardson to evaluate your eyes for glaucoma call 626-289-7856 now. No referral required. Appointments are available, Tuesday through Saturday.