How to protect the macula in patients with diabetes mellitus?

Diabetes mellitus is a disease that can cause serious damage to all organs in the human body. Diabetic retinopathy is one of the most severe complications of diabetes mellitus (Fig. 1). It is one of the leading causes of reduced vision, which can lead to complete blindness in people of active and advanced age. Currently, there are approximately 92.6 million diabetics worldwide, of whom 28.4 million have visual impairment. In Bulgaria, there are over 500,000 patients with diabetes mellitus. This disease is characterised by its early stages being painless and without clearly expressed subjective complaints. Initially, patients usually see relatively well and do not feel any problems. Gradually, signs such as visual fatigue, increased light sensitivity, blurred or unclear vision, and difficulty focusing on details may appear. When these symptoms become noticeable, changes in the retina are often already advanced and require intensive treatment.

Statistics show that between 60% and 80% of patients with diabetes mellitus develop diabetic retinopathy within approximately 10 years of the onset of the disease. The risk is higher with a longer duration of diabetes mellitus, poor metabolic control of the disease, concomitant arterial hypertension, and dyslipidemia (1, 2, 3). Regular prophylactic eye examinations allow for early detection of the disease, when treatment is more effective and permanent vision damage can be prevented.

Vascular and neuronal damage to the retina can occur even in the early stages of diabetes mellitus (4). This explains why many patients experience subtle changes in vision, such as reduced contrast sensitivity, poorer dark adaptation, and faster visual fatigue, even before a diagnosis of diabetic retinopathy is made.

The retina has natural protective mechanisms. In its central zone – the macula – there is macular pigment, which protects nerve cells, filters harmful blue light, and reduces oxidative stress. This pigment is composed of three specific carotenoids: lutein, zeaxanthin, and meso-
zeaxanthin, which the body cannot synthesise on its own and must obtain from external sources. In patients with diabetes mellitus, this protective reserve is depleted significantly faster. It has been established that people with diabetes mellitus and diabetic retinopathy have a lower density of macular pigment, which makes this part of the retina more vulnerable to inflammatory factors and oxidative stress, leading to faster progression of damage.

The pigment in the macula depends on many factors and decreases by an average of 1% per year between the ages of 25 and 55. After the age of 55, the loss of macular pigment progresses significantly faster. Several clinical studies investigate how the level of macular pigment in healthy individuals is related to the main risk factors that cause macular damage and loss of central vision (5, 6). The results are of significant importance for people with existing risk factors such as family history and smoking, as they have lower levels of macular pigmenteven before the clinical manifestations of eye disease have developed.

Numerous randomised clinical trials in patients with diabetic retinopathy show that the intake of macular carotenoids leads to an increase in macular pigment density and an improvement invision (7, 8, 9). Chronic macular edema is a leading cause of low vision in all forms of diabetic retinopathy. Along with conventional treatment of diabetic macular edema through VEGF inhibitors, the intake of carotenoids significantly influences the regression of edema and improves visual functions (7, 8). Better contrast sensitivity, more stable vision, and less visual fatigue are reported. According to literature data, this effect is significant even in the absence of advanced vascular changes, which highlights the need for early retinal protection (10).

In this context, the product MACUSHIELD offers targeted vision protection (Fig. 2). Only MACUSHIELD contains all three carotenoids – lutein, zeaxanthin, and meso-zeaxanthin – which make up the macular pigment. Meso-zeaxanthin is a key component of macular pigment and plays a leading role in neutralising free radicals in the very centre of the macula. It is almost not found in the standard diet and is absent in other eye products. It is recommended for both diabetic patients and healthy individuals with intensive screen work and visual fatigue. Regular intake of MACUSHIELD increases macular pigment density and supports long-term preservation of visual function.

The MACUSHIELD formula is offered in an oil solution, which ensures better stability and bioavailability of the carotenoids within it. The oil medium protects the active ingredients from oxidation and allows them to reach the retina in an active form. This is a significant advantage
that provides long-term vision protection. When the retina is under constant oxidative stress, protection must be reliable, long-lasting, and scientifically substantiated. One MACUSHIELD capsule daily is a small step today that can have significant importance for vision tomorrow.
Daily intake of MACUSHIELD increases macular pigment density and slows down retinal damage in patients with diabetes mellitus.

Regular eye examinations, good metabolic control, and adherence to the endocrinologist’s recommendations remain key elements in caring for the vision of patients with diabetes mellitus. Combining these with targeted, long-term macular protection can help slow down pathological processes and preserve the quality of life of patients.