New insights into the disease processes of glaucoma are changing the understanding of eye disease. Primary open-angle glaucoma (POAG) is a slowly progressive disease of the optic nerve. Gradually, the retinal ganglion cells are lost and the optic nerve dies. If left untreated, glaucoma leads to blindness. Treatment for the eye disease, which affects around 923,000 people in Germany, has so far focused on reducing intraocular pressure to slow its progression.
The intraocular pressure is lowered with eye drops, if necessary also with laser interventions or operations. In addition to this therapy, a change in diet and lifestyle can have a positive effect on the course of the disease.
A systemic neurodegenerative disease
The cause of POWG has not yet been studied in great detail, but it is now known that, like Alzheimer’s disease or Parkinson’s disease, it is a systemic neurodegenerative disease. The basic disease mechanisms affecting the optic nerve are inflammatory processes (neuroinflammation) and oxidative stress. Both contribute to the progressive degeneration of the optic nerve.
Oxidative stress is when an excess of reactive oxygen compounds occurs during metabolic processes. These compounds, also known as free radicals, can attack the cell’s own structures such as mitochondria, the powerhouses of the cell. Excessive intraocular pressure – an important risk factor for glaucoma – hinders, among other things, the supply of oxygen-rich blood to the optic nerve. This creates a lack of oxygen (hypoxia). A chain reaction develops in which the interactions between oxidative stress, damaged mitochondria and inflammatory processes mutually favor each other (2).
Since lowering intraocular pressure cannot stop the progression of glaucoma in all patients, there is an intensive search for additional therapeutic approaches. Reducing oxidative stress is an approach that can complement available treatment strategies.
Glaucoma risk factors: high blood pressure, diabetes, dyslipidemia
Besides its importance for neurodegenerative diseases, oxidative stress is also implicated in the development of high blood pressure and diabetes. High blood pressure, vascular dysfunction, diabetes mellitus, and dyslipidemia are considered important systemic risk factors for the development of POAG. These risk factors can be positively influenced by a healthy and varied diet.
A new aspect that research is focusing on is the gut microbiome. There is some interesting evidence that the composition of the gut microbiome is different in people with glaucoma and in people without glaucoma (3). The term microbiome refers to all microorganisms, in this case in the human intestine. The role that the gut microbiome plays in the body’s inflammatory processes and in neurodegenerative diseases is currently the subject of intensive research. A change in diet can affect the composition of the microbiome. The therapeutic potential for the treatment of glaucoma needs to be further explored.
Tips for healthy eating – also for the eyes
A varied, vitamin-rich and healthy diet is therefore also beneficial for the eyes in various ways and can support the treatment of glaucoma, which lowers intraocular pressure. In addition, such a diet also protects against other eye diseases such as age-related macular degeneration.
The following tips can help you:
It makes sense to eat regularly at set times to adjust to the body’s circadian rhythm.
Foods high in fat should be avoided to reduce levels of harmful LDL cholesterol in the blood.
Sugar should also only be consumed in small amounts to prevent obesity, type 2 diabetes and other secondary diseases.
Vegetables and fruit, on the other hand, can be eaten in abundance – the German Nutrition Society recommends “5 a day” – i.e. three servings of vegetables and 2 servings of fruit per day. So that these foods end up on the plate with a maximum of vitamins, it is advisable to choose products that can be transported over short distances.
High quality oils such as olive oil are also rich in vitamins and valuable fatty acids.
Coffee should not be consumed in excess.
In consultation with the ophthalmologist, it may also be a good idea to take antioxidant dietary supplements in order to achieve the effective levels of the desired substances in the body.
Do not smoke – drink little alcohol – play sports
Additional measures that benefit the whole body and also promote eye health are abstinence from nicotine, limiting alcohol consumption and sports activities – but the latter without pressure to perform. Exercise can also slow disease progression. Relaxation exercises such as autogenic training can also complement eye pressure reduction treatment.
The understanding of POWG is changing. We now know that it is part of the neurodegenerative diseases. The traditional treatment is to lower intraocular pressure. In this way, the progression of the disease can be partially stopped and vision preserved. Risk factors such as high blood pressure, diabetes mellitus or dyslipidemia can be positively influenced by a change in diet and lifestyle. A healthy lifestyle with a varied diet, regular physical activity, little alcohol and avoiding nicotine is also beneficial for eye health.