OUR EXPERIENCE OF ANTIOXIDANT THERAPY OF DIABETIC CATARACT BASED ON N-ACETHYLCARNOSINE

Corresponding member NAMSU, prof. Veselovskaya Z.F. , prof. Veselovskaya N.N. , Assoc. Zherebko I. B.   

Kiev Medical University UANM, Kiev, Ukraine 

Kiev City Ophthalmological Center KGKB No. 1, Kiev, Ukraine  

 

The paper presents an analysis of the use of acetylcarnosine in patients with diabetic cataract. The observation period was 6 months. The data obtained indicate that acetylcarnosine, which is contained in the drug "Clarastil" 1 %, slows down the progression of pathological processes in the lens in patients with non-insulin dependent diabetes mellitus. 

Key words: oxidative stress, diabetes mellitus, acetylcarnosine, cataract. 

 

 

Relevance. Diabetes mellitus (DM) is one of the most common diseases of the endocrine system today. Every year the number of patients in all countries of the world is increasing significantly, and among them there are more and more young people. Since 1980, the number of people with diabetes has quadrupled. Disappointing statistics from the WHO indicate that diabetes mellitus is one of the main causes of blindness and 1 % of people with visual impairment are people with diabetes [7]. Often, against the background of diabetes mellitus, cataracts also develop [8]. Fulfilling the role of a biconvex refractive lens in the human eye, due to which the light rays are focused on the retina, the lens becomes denser and cloudy with age, which leads to a gradual decrease in vision.  

In patients with diabetes mellitus, especially decompensated, the process of lens opacity begins earlier through metabolic disorders and deterioration of the trophism of the lens [6]. Quite often, cataracts significantly complicate the course, diagnosis and treatment of diabetic retinopathy.

The composition of the lens substance includes: water (about 65 %), proteins (about 35 %), mineral salts and trace elements (sulfates, phosphates, chlorides, K, Mg, Fe, Cu, Zn, Mn, B, etc.), lipids (lecithin and cholesterol), glutathione, ascorbic acid.  

With changes in the lens, its density increases, the metabolism in cells slows down, and the ability to accommodate decreases. During this period, opaque areas begin to form in the lens, which is the main symptom of cataract and is accompanied by a decrease in visual acuity.

As a result of changes in the chemical composition of the lens cells, the water content in them increases, an imbalance of a number of substances arises, the activity of enzymes involved in metabolism decreases, the absorption of oxygen sharply decreases, the processes of lipid peroxidation accelerate [9]. In modern medicine, it is generally accepted that age-related opacities in the lens are a consequence of free radical oxidation reactions [10]. The most significant factor that provokes the formation of free radicals in the tissues of the eye are light waves. Oxidative stress is a pathological condition caused by the presence in the body of an excessive amount of free radical particles or a reduced efficiency of the antioxidant system [8]. The increased formation of reactive oxygen species (prooxidants) and a decrease in antioxidant defense cause chronic oxidative stress in the tissues of the eye, creating conditions not only for the development of cataracts, but also for diabetic changes in the fundus.

Excessive formation of free radicals in the lens leads to the accumulation of toxic compounds, as well as to irreversible changes in proteins against the background of a gradual decrease with age in the activity of antioxidant enzymes and a decrease in the concentration of natural antioxidants [4; 6].

As a result, for the prevention of lens opacity, substitution therapy is widely used, which ensures the entry of substances into the cells, with the lack of which the development of cataracts is associated. Currently, antioxidants are divided into two main large groups depending on their solubility in water: hydrophilic and lipophilic [11].

Known water-soluble antioxidants, thiol antioxidants and their chemical derivatives, which have recently been isolated as anti-cataract agents, are N acetylcarnosine [2; 3], N-acetylcysteine ​​and N-acetylcysteinamide, GSH (glutathione), cysteine, cysteine ​​prodrug L-2-oxothiazolidine-4-carboxylic acid (OTC). N-acetylcarnosine inhibits membrane lipid peroxidation and is a prodrug of carnosine [1; five].

Aim - to study the results of the use of N acetylcarnosine in patients with cataracts on the background of diabetes mellitus. 

Materials and methods. We observed two groups of patients. The first group included 29 patients (58 eyes) aged 43–60 years: 20 women (40 eyes) and 9 men (18 eyes) with cataracts of I, II degree of density according to Buratto's classification against the background of diabetes mellitus. These patients used the drug "Clarastil" 1 % (N acetylcarnosine) 1-2 drops twice a day for 6 months.  

The second group also consisted of 29 patients (58 eyes) aged 43–60 years: 19 women (38 eyes) and 10 men (20 eyes) with cataracts of I, II degree of density according to Buratto's classification against the background of diabetes mellitus. They used placebo - moisturizing drops 1-2 drops twice a day for 6 months.

Visual acuity in patients of the first and second groups varied from 0.7 to 1.0. Diabetic changes in the fundus were absent in both groups.

Patients were assessed the level of glycemia and glucosuria, glycosylated hemoglobin HbA1C, and also underwent ophthalmological examination, which included visometry, tonometry, computer perimetry, OCT, ultrasound examination in A-scan mode , echobiometry, photographic recording of the anterior segment, biomicroscopy of the lens body and glass microscopy. ... 

The studies were repeated every 2 months and compared with previously available data.

Results. According to systemic examination data, all patients were in the stage of diabetes compensation and under close supervision of an endocrinologist. Table 1 presents an analysis of the results of observing the dynamics of changes in visual acuity (AO) in patients with different regimens of using eye drops. The data obtained showed that in both groups the dynamics of changes in OZ during 6 months was different, mainly towards more positive changes in the first group. 

So, after 6 months, the patients of the first group showed stabilization of visual acuity at the level of 0.7–1.0 in 38 eyes (65.5 %) and an improvement in OZ by 0.1 in 4 eyes (7.0 %). However, in this group, there was also a decrease in visual acuity to 0.5-0.6 in almost a third of the eyes (in 16 eyes), which amounted to 27.5 %. We associated this deterioration both with the progression of cataracts (thickening of the nucleus and cortical part of the lens) and with the occurrence of clinical manifestations of diabetic edema of the macular region (DME) in 2 eyes (3.4 %).    

In the second group, a decrease in OZ within 0.3 (from 0.4 to 0.7) was observed in 41 eyes, which was 70.6 %, and was explained both by the compaction of the nucleus and the progression of opacity in the cortical regions of the lens, and by the appearance of signs of DME. among these patients, but not two, but seven eyes (12.1 %).  

 

Table 1

Comparative evaluation of the use of N-acetylcarnosine ("Clarastil") and moisturizing eye drops in the treatment of cataracts in patients with diabetes mellitus 

 

Groups

Dynamics of changes in visual acuity (abs. -%) after 6 months

 

Deterioration

Stabilization

Improvement

The first

16 eyes - 27.5 % 

38 eyes - 65.5 % 

4 eyes - 7.0 % 

The second

41 eyes - 70.6 % 

17 eyes - 29.3 % 

-

 

The appearance of DME was diagnosed by the presence of negative dynamics in the macular region according to OCT data: an increase in the thickness of the retina of the macular region within 15.0–20.0 % of the initial data. 

According to the survey, all examined patients when using eye drops based on N-acetylcarnosine did not experience visual discomfort, irritation, dryness or hyperemia of the eyelids and the surface of the eyes, and other side effects at the systemic level, which indicated good tolerance of N acetylcarnosine (Clarastila ») With a high safety profile. To a certain extent, this can be explained by the fact that N-acetylcarnosine ("Clarastil") has pronounced antioxidant, cytoprotective and hydrating properties, which are extremely important for long-term use. The presence of these properties is of great importance for patients with systemic endocrine diseases, such as diabetes mellitus, since it is this pathology that leads to the development of tissue hypersensitivity to any kind of influences. In addition, the antioxidant profile of the pharmacological action explains the rather high efficiency not only against cataracts, but also diabetic changes in the macular region. This is confirmed by the data of our study - a large number of patients with DMO in the control group.    

conclusions

  1. Long-term use of eye drops based on N acetylcarnosine ("Clarastil") in patients with the initial stage of cataract against the background of diabetes mellitus contributes to the positive dynamics of the clinical picture, stabilization and improvement of visual acuity, which is almost 2.5 times higher than in the control group.
  2. Long-term use of eye drops based on N acetylcarnosine ("Clarastil") in patients with the initial stage of cataract against the background of diabetes mellitus contributed to the stabilization of the macular region in 96.6% of patients, which was 6.9% higher than in the control group. 
  3. The obtained data indicate the clinical efficacy of long-term use of eye drops based on N acetylcarnosine ("Clarastil") - the only drug registered in Ukraine with this mechanism of action, which helps to stabilize cataractogenesis, prevent cataract progression and the development of diabetic changes in the fundus in patients with diabetes.

 

 

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