RU2314072C1 - Method for preventing the development of diabetic macular edema in patients at type ii diabetes - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: it is necessary to apply laser coagulates in area of papillomacular bundle and concentrically in 3 mm area around the fovea. One should apply laser radiation at wave length of 532 nm in sub-threshold mode, at power ranged 0.05-0.08 V, impulse duration being 0.1 sec, spot's diameter - 100 mcm, the quantity of coagulates ranged 100-170.

EFFECT: higher efficiency of prophylaxis.

3 dwg, 3 ex

Description

The invention relates to ophthalmology and can be used to prevent diabetic macular edema in patients with type II diabetes mellitus.

The leading cause of fatal vision loss in diabetic retinopathy is diabetic macular edema (Bresnick G.H. Diabetic macular edema // Ophtalmology. - 1986. - Vol.93, No. 7 - P.938-950). According to the data provided by the international treatment group Early Treatment Diabetic Retinopathy Study (ETDRS Research Group, report number 1. Photocoagulation for diabetic macular edema // Arch. Ophtalmology - 1985. - Vol.103. - P.1796-1806.), Moderately severe vision loss with clinically significant diabetic macular edema (DME) reaches 32% within five years of observation. With a duration of diabetes from 10 to 15 years, DMS develops in 95% of patients.

There are ways to treat an already developed DME. Their main point is to apply laser coagulates to the edematous retina. In this case, the treatment mechanism consists in creating a chorioretinal shunt, stimulating the macrophage function of the retinal pigment epithelium (Ziangirova G.G. et al. // “Bulletin of Ophthalmology” - 1982. No. 4. - p. 51-57), the destruction of “weak” cells pigment epithelium, stimulation of its phagocytic activity, proliferation of pigment epithelium, destruction of part of the actively consuming oxygen photoreceptors (Bresnick GH Diabetic macular edema // Ophtalmology. - 1983. - Vol.90, No. 11 - P.1301-1317). There are no laser-surgical methods for preventing DMO.

The group of people with a high risk of developing DME includes patients with type II diabetes mellitus (DM II) who have a disease duration of more than 7.3 years, an uncompensated course of diabetes, the presence of nephropathy, hypertension, transfer to insulin therapy, a retinal volume of more than 7.5 mm ³ , hyperopic refraction, age over 56 years.

The task is to propose a method for the prophylaxis of DME in patients with type II diabetes.

The technical result is the preservation of the initial volume of the retina of the macular region by creating a skeleton in the retina of laser coagulates, as well as enhancing the function of the retinal pigment epithelium as a result of exposure to the energy of the diode laser. The initial volume of the retina of the macular region means the volume of the retina of the macular region in patients with type II diabetes who do not have signs of DME.

The technical result is achieved by the fact that patients with a high risk of developing DMO are subjected to subthreshold laser retinal coagulation in the macular region. Laser coagulation was performed using a Carl Zeiss Visulas diode ophthalmocoagulator, wavelength 532 nm. Laser coagulation was performed in a subthreshold mode. The determination of the threshold was carried out outside the temporal vascular arcades (figure 1). In this case, coagulates with a diameter of 100 μm were applied with the energy parameters necessary to obtain coagulate 1 tbsp. by Le Esperance (gray coagulum with fuzzy contours); then the power and duration of the pulse decreased until they received a coagulate that was barely visible in the "red" light (obtained by using a filter neutralizing the red part of the spectrum). After that, 30% was taken from the received power and the retinal coagulation of the macular region was performed. The impact is carried out in the areas of the macular region, where the DMA is most often primarily localized, this is the zone of the papillomacular bundle and the concentric 3 mm zone around the fovea (Fig. 2). Thus, the parameters of laser coagulation were: power 0.05-0.08 W, pulse duration 0.1 s, spot diameter 100 μm, the number of coagulates from 100 to 170. These parameters of laser coagulation can affect only the pigment epithelium without damage to photoreceptors the retina. As a result of coagulation, a framework 1 is created in the layers of the retina 2 (Fig. 3), which does not allow the volume of the retina to increase in the macular region and prevents the development of DME.

The advantages of the method:

- allows you to prevent the development of DME, because the resulting framework of laser coagulates does not allow the development of intra-retinal edema;

- retinal photoreceptors are not damaged, because the energy of subthreshold coagulation does not cause tissue heating sufficient to damage photoreceptors;

- reducing the invasiveness of the intervention, because it is carried out only in areas where DME most often develops;

- an individual approach to each patient, because Energy parameters of laser coagulation are selected individually. We observed 18 (36 eyes) patients with type II diabetes with a high risk of developing DMO. Patients were divided into 2 groups: the first included 10 people (20 eyes) who underwent prophylactic subthreshold laser retinal coagulation (PSPLKS); in the 2 group there were 8 people (16 eyes) who were controlled.

Dynamic monitoring was carried out for 18 months with a frequency of examinations of 1 time in 3 months. In this case, the ophthalmoscopic picture of the fundus and the volume of the retina in the macular region were evaluated.

By the end of the observation, there was no increase in the volume of the retina in the macular region in 18 eyes of the first group, of which microaneurysms and single intraretinal hemorrhages appeared ophthalmoscopically in 10 eyes. In two eyes, focal DMO developed outside the fovea, with an increase in the volume of the retina in the macular region by 0.42 and 0.72 mm ³ .

In the second group, focal DME developed in 9 eyes, and diffuse DMO in 3 eyes. In 4 eyes of this group, the development of DME was not noted.

Example 1. Patient U., 58 years old, is ill with type II diabetes for 8 years, the course of the disease is severe, diabetic nephropathy, hypertension 1 tbsp., Insulin therapy for 2.5 months. In ophthalmic status: visual acuity of both eyes 1.0 with correction of 1.5 diopter spheres, PZO OD 22.45 mm, OS 22.50 mm, optical media transparent at the fundus there are no signs of DME, single microaneurysms, macula volume 7.52 mm ³ . When selecting energy, a barely noticeable coagulum in "redless" light was obtained at a power of 0.07 W, exposure time 0.1 s, spot diameter 100 μm. Conducted PSPLKS, laser coagulation indicators: power - 0.05 W, exposure - 0.1 s, spot diameter - 100 μm, the number of coagulates - 126. 18 months after the PSPLKS on the fundus there are no signs of DMT, the macula volume has not changed. It should be noted that compensation for the course of the underlying disease has been achieved.

Example 2. Patient X., 61 years old, type II diabetes 7.5 years, the course of the disease is moderate, hypertension 1 tbsp., Nephropathy, in ophthalmic status: visual acuity of both eyes 1.0 with a correction of the scope of 1.0 diopter, PZO OD 22.68 mm, OS 22.80 mm, optical media are transparent, there are no signs of DME on the fundus, single microaneurysms, macula volume 7.63 mm ³ . When selecting energy, a power of 0.09 W was obtained, PSPLKS was carried out, laser coagulation indicators: power - 0.06 W, exposure - 0.1 s, spot diameter - 100 μm, number of coagulates - 135. After 18 months, the volume of the macula is stable, in ophthalmic status without negative dynamics.

Example 3. Patient Yu., 59 years old. Type II diabetes mellitus 8.5 years, the course of the disease is moderate, hypertension 2 tbsp., Nephropathy. In ophthalmic status: visual acuity of both eyes 0.9 with a sphere correction of +2.0 on OD, +1.75 on OS, PZO OU 22, 45 mm, initial cataract, on the fundus without pathology, macula volume 7.62 mm ³ . The patient refused the proposed PSPLKS. After 12 months, the examination revealed a focal DMO, the volume of the macula increased to 8.06 mm ³ .

Claims (2)

1. A method for preventing the development of diabetic macular edema in patients with type II diabetes mellitus, which consists in applying laser coagulates, characterized in that the laser coagulates are applied in the area of the papillomacular bundle and concentrically in the 3 mm zone around the fovea, using the Carl Zeiss Visulas ophthalmic coagulator "With a wavelength of 532 nm in a subthreshold mode, with a power from 0.05 to 0.08 V, a pulse duration of 0.1 s, a spot diameter of 100 μm, the number of coagulates from 100 to 170. 2. The method according to claim 1, characterized in that to determine the threshold, coagulates are first applied outside the temporal vascular arcades with a diameter of 100 μm, reducing the power and duration of the pulse until a coagulate is barely visible in the "red" light, then 30 are taken from the received power % and already this power is applied to the coagulates that form the lattice.

Images