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Glaucoma, Curcumin, and Autoimmunity: Exploring the Research

Linda Crampton is a writer and teacher with a first-class honors degree in biology. She often writes about the scientific basis of disease.

New Discoveries Related to Glaucoma

Glaucoma is a potentially serious eye problem. In the most common form of the disease, fluid builds up in the eyeball. The fluid creates pressure that damages the retinal ganglion cells located at the back of the eyeball. The long fibers of these cells are known as axons and form the optic nerve. The nerve is vital for vision because it transmits signals from the eye to the brain. If glaucoma is not treated and the optic nerve is damaged, vision loss may result.

Researchers have recently discovered that a chemical called curcumin from turmeric helps to treat early glaucoma in rats (when the chemical is formulated correctly). The formulation might be helpful in humans as well. Other researchers have found evidence supporting the idea that glaucoma is an autoimmune disease. If this idea is true, new and more effective treatments may be created.

Parts of the Eye

In order to understand the problem that contributes to vision loss in glaucoma, it's helpful to know a little about the anatomy of the eye. The cornea is the transparent layer over the front of the eye. The iris is the colored part of the eye. It has a circular gap in the center called the pupil. The pupil allows light rays to reach and travel through the lens, which is located behind the iris. The size of the pupil varies, depending on light conditions. The light rays travel through the vitreous humour located behind the lens and then strike the retina.

The light triggers the creation of electrical nerve impulses in the retina. Retinal ganglion cells are located at the back of the retina. They send impulses along the optic nerve to the brain, which produces an image.

What Is Glaucoma?

The spaces between the cornea and the lens are filled with a fluid called aqueous humor, which provides nourishment to eye tissues. The aqueous humor is secreted by the ciliary body, moves through the posterior chamber behind the iris, and then travels through the anterior chamber in front of the iris. It's removed through drainage canals located between the edge of the iris and the cornea.

If the fluid exit area is narrowed or the drainage canals are blocked, an insufficient quantity of fluid may leave the eye. Intraocular pressure (the pressure inside the eyeball) may then increase. The pressure may be transmitted through the largest chamber of the eye, which is filled with a gel known as vitreous humor, and press on the retina at the back of the eyeball. This can damage the retinal ganglion cells and the optic nerve produced from their axons.

It should be noted that optic nerve damage and glaucoma sometimes develop without an increase in fluid pressure within the eyeball. This suggests that we don’t completely understand the condition yet. Unfortunately, people may not notice a vision problem or seek medical help until the disease is quite advanced and a considerable number of retinal ganglion cells have been lost.

The Turmeric Plant and Spice

Turmeric is a flowering plant in the ginger family (the Zingiberaceae) that’s native to India and Southeast Asia. Its rhizome, or underground stem, is used to create a yellow-orange powder. The powder is used as a spice and is also known as turmeric. Curcumin is a chemical in the spice.

Turmeric and curcumin might be capable of providing several wonderful health benefits. It’s been hard to prove this, though. For example, turmeric is a popular component of the diet in India and Asia. It has been noted that the incidence of Alzheimer’s disease is significantly lower in these parts of the world than in other areas. The Alzheimer’s Society in the UK says that turmeric ingestion is unlikely to be responsible for this observation, however. Interestingly, they don’t completely dismiss the benefit of the spice. They note that in lab equipment curcumin has been found to have antioxidant, anti-inflammatory, and anti-amyloid properties. Abnormal brain deposits of a protein called beta-amyloid are a characteristic of Alzheimer’s disease.

We have some evidence, if you look at the in vitro cellular studies, if you look at animal studies, the evidence is very strong. But humans are not animals. We need to provide more evidence from clinical trials … to get solid evidence of the health benefits of curcumin.

— Professor Manohar Garg, University of Newcastle, via the Australian Broadcasting Corporation

Improving the Absorption of Curcumin

One problem with obtaining the required proof for its benefit might be that curcumin is poorly absorbed by the gut. Benefits demonstrated in cells or tissue in lab equipment are not always duplicated in the body. A patient would have to take a huge dose of turmeric or curcumin in order to absorb enough to be helpful (assuming the substance is beneficial for the patient’s condition). This would not only be inconvenient but would likely cause gastrointestinal distress. There is hope that the absorption of curcumin will soon be improved, however.

Ingesting black pepper with curcumin or turmeric increases the bioavailability of curcumin by around 2,000 percent. Bioavailability is the proportion of a drug that has an active effect in the body. A new discovery may be even more helpful. Researchers in Britain have created a nanocarrier for curcumin that they say increases its solubility in eye drops by an amazing 400,000 times. In addition to the increased solubility, another advantage of the nanocarrier is that it would enable doctors to place the substance directly in the eyes instead of providing an oral medication.

A nanometer is a billionth of a meter. The word “nanoparticle” general refers to particles with a diameter of one to a hundred nanometers. A nanocarrier is a molecule or particle on the nanoscale that is used to carry medicinal drugs through the body. The carrier may be a little larger than a traditionally-defined nanoparticle but is still very tiny. A nanocarrier has features that enable it to effectively ferry a drug to the area where it’s needed. Without the carrier, the drug may not be absorbed by the correct area.

Glaucoma is a group of eye conditions affecting over 60 million people worldwide that leads to irreversible blindness in 1 in 10 cases.

— University College London, via ScienceDaily

Curcumin in a Rat Model of Glaucoma

The term “animal model” is often used by researchers. The term means that although it seems that a lab animal has the same disease as humans, we can’t be absolutely certain that the disorder is the same or is occurring by the same processes as in the human body. A discovery in lab animals often applies to humans, but this isn’t always the case.

Scientists at University College London and Imperial College London recently used a rat model to study the effect of curcumin attached to a nanocarrier on glaucoma. The scientists administered the eye drop medication twice a day over a period of three weeks to rats who had retinal ganglion loss. Another group of rats with the same condition was untreated. The further loss of retinal ganglion cells was significantly reduced in the treated rats compared to the untreated ones and there were no signs of eye irritation from the treatment.

Current treatments for glaucoma include eye drops, laser treatment, and surgery. Eye drops containing one of a variety of drugs are commonly used. The drugs reduce fluid buildup and pressure in the eye by various methods. They are often helpful but can also produce side effects. In addition, in some patients retinal ganglion cells are harmed even when intraocular pressure is normal. A medication such as curcumin might be very useful in protecting cells in the retina.

The Possible Role of T Cells

An autoimmune condition is one in which our immune system mistakenly attacks our body’s own tissues. The immune system is supposed to protect us from pathogens that cause disease or harm, which it often does admirably (though it sometimes needs help). Its attack on our cells can cause a range of health problems.

A team of researchers from the Massachusetts Institute of Technology, the Massachusetts Eye and Ear Institute, and other institutions has found evidence suggesting that glaucoma is—or is at least sometimes—an autoimmune disease. Like other observers, the researchers have noticed that in both humans and mice, even when intraocular pressure decreases, vision sometimes continues to get worse. This has suggested to the researchers that some other progressive condition occurs in the disease.

The researchers found T cells in the retina of mice with glaucoma (or with a disease closely resembling it). T cells are important in the immune system’s attack on an invader. The discovery was puzzling because T cells are normally prevented from entering the retina by the blood-retina barrier, which is a tightly-packed layer of cells. In mice, when intraocular pressure was high, the T cells were able to pass through this barrier.

Other researchers involved in the study had mice without T cells in their lab. The scientists triggered an increase in intraocular pressure in the mice, which caused a small amount of damage to their retina. When the scientists reduced the pressure, no further damage to the retina occurred.

Heat Shock Proteins and Autoimmunity

Additional studies by the Massachusetts researchers discovered how T cells may damage the retina in glaucoma patients. The presence of the cells appears to hinder molecules known as heat shock proteins. These molecules help cells to respond to stress and injuries.

Heat shock proteins in bacteria and humans are quite similar. The researchers suspect that the T cells that entered the retina had been “programmed” to target the human proteins after coming into contact with the bacterial ones.

Perhaps very significantly, the researchers found that people with glaucoma had five times the usual level of T cells that target heat shock proteins. The researchers don’t believe that a specific bacterium is required to create these T cells but think that the production is a response to the presence of bacteria in general. Interestingly, when the researchers tried to trigger glaucoma in a group of mice that contained no bacteria, they were unable to do so.

T cells in our body normally don't target our own heat shock proteins, but in glaucoma patients some may do so. This is a type of autoimmune response. When the abnormal T cells enter the retina due to high intraocular pressure, they may damage the retinal ganglion cells and may continue to do so after the pressure is reduced.

The disease often goes undetected at first; patients may not realize they have the disease until half of their retinal ganglion cells have been lost.

— Anne Trayvon, MIT News Office

The Hope of Improved Treatments

The new discoveries are intriguing, but further research is needed. We need to discover whether the specially-formulated curcumin helps humans as well as rats. We also need to understand glaucoma better. An autoimmune response may be involved in some people with the disease but not in everyone. It's puzzling that some people suffer from glaucoma without developing high intraocular pressure.

Despite the need for further investigations, the recent discoveries could be very significant and may lead to better treatments for the disease. In addition, the discoveries related to T cells may occur in other diseases, including some that occur in the brain and some other autoimmune conditions. T cells are common and important cells in our body, so if they “misbehave” the results can be serious.

It would be wonderful if the latest research eventually helps not only glaucoma patients but also people with other diseases. With respect to glaucoma, however, diagnosing the condition as soon as possible is important while the current treatments are available and will probably still be important if new treatments are created. This is one reason why it's a good idea to get our eyes checked regularly by an ophthalmologist. A checkup is especially important for older people, who are more likely to get glaucoma than younger ones. An eye doctor can detect problems before a patient is aware of them. Fighting glaucoma by all of the methods that are available is advisable.

References

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Questions & Answers

Question: Is turmeric a blood thinner?

Answer: It may be. The evidence appears to be inconclusive at the moment. Some health agencies recommend that if someone is taking a medicine to reduce blood coagulation, or to thin their blood, they should ask their doctor about the advisability of taking turmeric or curcumin as well. Some suggest that high doses of turmeric or curcumin should be avoided until the situation is clearer. Even if curcumin is a blood thinner when taken orally, however, we don’t yet know if properly-formulated curcumin will have the same effect in a glaucoma medicine (if such a medicine is ever created for humans).

© 2018 Linda Crampton

Comments

Linda Crampton (author) from British Columbia, Canada on July 22, 2020:

I'm sorry about your husband's eye problems, Denise. It would be wonderful if researchers discover that curcumin helps and that they discover the concentration that's both safe and effective.

Denise McGill from Fresno CA on July 22, 2020:

My husband had a Branch Vein Retinol Occlusion about 5 years ago. Apparently a vein in the back of the eye burst and sent blood throughout the vitriol humor but also deprived the retina in a patch of oxygen. By the time he got an appointment and in to see an eye specialist the damage had already been done. He squints a lot like Popeye because that one eye caused a bit of a double vision and he can't see above my eyebrows if I stand in front of him. On top of that, they discovered his eye pressure was up (glaucoma threat) and have been treating him with drops. Poor guy. He hates drops. But he hates not seeing worse so they scared him sufficiently to make him keep the drops up. I use Tumeric tea all the time for my joint pain. If it could help him that would be awesome.

Blessings,

Denise

Linda Crampton (author) from British Columbia, Canada on June 10, 2019:

Thank you for the comment. I always appreciate your visits. Actually, animals can get glaucoma. It's a shame when it happens in a pet.

RTalloni on June 10, 2019:

Such an interesting read on so many levels. I did not realize glaucoma might be an autoimmune disease. The more we learn about what our eyes have to say the more we understand how little we know about the human body and how different it is from an animal body. The old saying is true, in the end we are all just a lump of clay, but the life within us is full of mystery! The video comparing invaders to the body with invaders of a prosperous country helped put it in down-to-earth terms, but you always do a good job of writing posts to help every day people learn more about specific topics.

Linda Crampton (author) from British Columbia, Canada on October 11, 2018:

Thank you very much for the comment and for sharing the information, Glenn. I hope your eye pressure continues to stay under control.

Glenn Stok from Long Island, NY on October 11, 2018:

Linda, you gave a lot of useful information about glaucoma in your article, and about the possible future cures with substances such as curcumin in turmeric. Your discussion of nanocarriers was extremely interesting too, and you explained it well. It’s good to know there is so much ongoing research on alternative solutions in the field of glaucoma.

I’ve had narrow angle glaucoma and I have the laser treatment called Iridotomy to provide the proper drainage. It’s kept my pressure under control for over ten years now. I’m always interested in learning more about this condition, and your article was certainly very helpful.

Linda Crampton (author) from British Columbia, Canada on September 17, 2018:

I appreciate your comment, Ann. It would be sad to lose one's sight. Researchers are discovering some interesting factors that may eventually help eyesight, though, which is good.

Ann Carr from SW England on September 17, 2018:

This is fascinating, Linda. Glaucoma is a familiar word to me, as my father was an optometrist and told me all about various eye problems. He took good care of my eyes too!

Reading all these details now is therefore interesting for me. Eyes are so important to look after, of course. For me, the worst thing I can imagine is to lose my sight; so many beautiful things to miss out on.

Thanks for sharing all this information. You always manage to put it over in a clear and orderly fashion, good for the layman!

Ann

Linda Crampton (author) from British Columbia, Canada on August 19, 2018:

I appreciate the kind comment, Flourish. It would be wonderful if better treatments for glaucoma and other eye problems were created.

FlourishAnyway from USA on August 19, 2018:

Several older people I know have had glaucoma so I had special interest in reading this excellent hub. I hope that new research can continue to shed light on treatments for this disease.

Linda Crampton (author) from British Columbia, Canada on August 17, 2018:

Thank you very much for the kind comment, Genna. I'm glad that you have no sign of glaucoma.

Genna East from Massachusetts, USA on August 17, 2018:

Linda this is a terrific article. I recently had my eyes checked and my optometrist said there was no sign of glaucoma. For years, I didn't know much about this malady, except it is not a pleasant experience and can be potentially devastating and cause blindness. This hub certainly clears up a lot of misunderstandings, and that there is hope for improved treatments.

Linda Crampton (author) from British Columbia, Canada on August 14, 2018:

Thank you very much for the kind comment, Jackie. The other ingredient you are thinking of is probably black pepper. As I say in the article, it's known to boost the absorption of curcumin from turmeric very significantly. I agree with you that it definitely seems worth eating the combination (in moderation).

Jackie Lynnley from the beautiful south on August 14, 2018:

Very interesting, Linda. I myself probably have no fear of Glaucoma (although I am checked regularly) my husband does since his father suffered badly from it.

It probably would not hurt to up the Turmeric in our diets because even though it takes a bigger dose (and I read somewhere there is another ingredient that should be in it to make it beneficial and I do not recall what now) surely a steady diet may help, you think? Turmeric has so many benefit it would be wonderful if they could perfect it for beneficial consumption.

Frustrating when we put so much money into things to help us to only find out it probably did not good at all.

Keep up the good work. All your articles are fantastic.

Linda Crampton (author) from British Columbia, Canada on August 14, 2018:

Thanks for the comment and for sharing the interesting information, Dora. The turmeric plant could be very important.

Dora Weithers from The Caribbean on August 14, 2018:

People in this region have recently grasped the importance of turmeric and are beginning to grow it, primarily because of its reputed benefit to the arthritis patient. It is great to know that it has potential benefit also to the health of the eyes. I particularly appreciate the information and explanations on glaucoma.

Linda Crampton (author) from British Columbia, Canada on August 13, 2018:

Hi, Bede. Yes, plants seem to have a lot to offer us in terms of medicines. They are a wonderful resource. Thanks for the comment.

Bede from Minnesota on August 13, 2018:

Hi Linda, this is hopeful news for those with early stage glaucoma. So far, my eyes are healthy, but I’m on the look out, as it were, because my dad has glaucoma. It's amazing when scientists discover medicines in common spices or plants.

Linda Crampton (author) from British Columbia, Canada on August 13, 2018:

Hi, Heidi. Thanks for the visit. It can be sad when people develop eye problems, especially if treatments aren't successful.

Heidi Thorne from Chicago Area on August 13, 2018:

Have friends who have had glaucoma and/or cataracts. Tough! And though I'm taking it for other reasons, glad to hear that turmeric might have some positive impact on eye health, too. Thanks for the info!

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Thanks for the visit and the comment, Savanna.

Savanna H on August 12, 2018:

I found this very interesting.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Hi, Audrey. Thanks for the visit. I should probably eat more turmeric than I do. It's an interesting spice. I like the idea of combining it with ginger in a tea.

Audrey Hunt from Idyllwild Ca. on August 12, 2018:

I've been a turmeric and ginger tea drinker for years. Good to know turmeric may be helpful in the prevention of glaucoma. Enjoyed your informative hub very much. Thanks, Linda.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Thank you for the comment, Maren.

Maren Elizabeth Morgan from Pennsylvania on August 12, 2018:

Nice details.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Hi, Mary. I'm hoping that researchers learn more about turmeric. It would be sad if the spice and curcumin can be helpful but we're not benefiting from the substances because we're not using them in the right way.

Mary Norton from Ontario, Canada on August 12, 2018:

Thanks for the reminder around eye exam. I just had one in the Spring. My husband used to drink tumeric powder with pepper but we have no idea how helpful this was but further studies can enlighten us and there is much hope.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Hi, Peggy. Your advice about eye exams is excellent. I hope researchers discover the most effective way to use turmeric and curcumin and that the substances prove to very helpful.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

I'm sorry that you have the condition, Manatita. I think more research into curcumin and the best way to absorb it is very important. The substance may have some wonderful benefits. Thank you very much for the comment.

Peggy Woods from Houston, Texas on August 12, 2018:

This article of yours was most interesting. Everyone should have an annual eye exam. So many diseases can be caught in early stages if that is done...not only glaucoma. Using turmeric and black pepper together has been recommended for conditions like arthritis so it makes sense that it could possibly help in all autoimmune diseases.

manatita44 from london on August 12, 2018:

A very thorough and educational as well as interesting report. Curcumin I have heard of and I have in fact used it with black pepper to fight off colds. Some say that the lycopene in tomatoes can also help with fighting Glaucoma.

I have this condition and yes, it seems to be more prevalent in black and coloured people: I mean Asian, latin, middle-eastern and so forth. High Blood Pressure and Diabetes seem to affect us as well.

Perhaps more research is need on Curcumin and other health products. Some naturopaths claim to be able to cure the disease. Wonderful Hub!

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Hi, Liz. Better treatments would be great and a cure would be wonderful. I hope the research leads to good things.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Thank you for the comment and for sharing the information, Pamela. I hope you find relief from your osteoarthritis pain.

Liz Westwood from UK on August 12, 2018:

I read your article with interest, as I have a relative who suffers with glaucoma. It can be quite life-limiting, as it progresses towards sight loss. I hope that progress can be made towards better treatment of the condition and even a cure in the future.

Pamela Oglesby from Sunny Florida on August 12, 2018:

Linda, This is such an interesting article. I have never read about glaucoma being an autoimmune disease either. I learned a lot from your article.

I was told by my orthopedic doctor to use tumeric for osteoarthritis to reduce the inflammation. I bought pills, but now I have read that actually using the tumeric root and making a paste is more beneficial.

Thanks for an excellent article.

Linda Crampton (author) from British Columbia, Canada on August 12, 2018:

Thanks, Bill. It's good that you've been checked for glaucoma. I'm glad your eyes are healthy.

Bill Holland from Olympia, WA on August 12, 2018:

Fascinating once again, Linda! I've worn glasses all my life, but thankfully glaucoma is not something I show signs of.

Linda Crampton (author) from British Columbia, Canada on August 11, 2018:

Thank you very much for the visit and the comment, John.

John Hansen from Queensland Australia on August 11, 2018:

Linda, this was very interesting and very helpful to know, especially the fact that glaucoma may be an autoimmune disease. Thanks for sharing.