RU2308920C2 - Method for modified subthreshold panmacular retinal microphotocoagulation at diabetic macular edema - Google Patents

Abstract

FIELD: medicine, ophthalmology.

SUBSTANCE: at first, it is necessary to fulfill test retinal coagulation in the most distant macular parts of edema against the center due to applying the packs of impulses of 0.2 sec duration. One should match the energy till the appearance of slightly visible burns. Then the exposure should be reduced up to 0.1 sec. After that, one should carry out subthreshold microphotocoagulation, moreover, it is necessary to irradiate retinal pigment epithelium either under or in close distance against the source of local transudation. Subthreshold coagulates should be located at interval being equal to a coagulate's diameter in two or more rows concentrically around the source of permeation within the whole area of retinal local edema. Then it is necessary to treat the whole edema-free macular area. Coagulates should be located as radial rows at interval being equal to a coagulate's diameter, parafoveally at capturing the edges of avascular area. The innovation enables to remove the processes of transudation in area of local permeation and prevent the availability of new transudation foci at the whole distance of macular area, keep and improve visual functions in such patients.

EFFECT: higher efficiency.

5 dwg

Description

The technical field to which the invention relates.

The invention relates to methods for treating the organ of vision of patients with diabetic macular edema and is used in the field of clinical ophthalmology.

The level of technology.

Currently, the following laser treatment methods for focal diabetic macular edema are generally accepted:

focal suprathreshold laser coagulation - local irradiation of microaneurysms with signs of leakage and intraretinal microvascular anomalies (Meyer-Schwickerath G., Schott K. / Diabetic retinopathy and photocoagulation. Am. J. Ophthalmol. 1968; 66: 597-603);

trellised suprathreshold coagulation - staggering burns with an interval in the diameter of the burn within the edematous retina not closer than 500 μm from the center of the macula (Schatz H., Patz A. / Cystoid maculopathy in diabetics. Arch. Ophthamol. 1976; 94: 761-768 );

modified focal "grating" - a combination of the methods described above, when local radiation is combined with additional stitching burns (Olk RJ / Modified grid argon (blue-green) laser photocoagulation for diffuse diabetic macular edema / Ophthalmology. 1986; 93: 938- 950);

focal subthreshold microphotocoagulation is carried out according to the principle of focal suprathreshold laser coagulation, i.e. localized irradiation of microaneurysms with signs of leakage and zones of intraretinal microvascular anomalies (Friberg TR Karatsa EC / The treatment of macular disease using a micropulsed and continuous wave 810-nm diod laser / Ophthalmology., 1997; 104 (12): 2030-2038), moreover, using micropulse and subthreshold irradiation modes that are created using special diode laser systems, such as the IRIS Medical IQ 810 Laser System (IRIDEX, USA) and ALOD-01 (ALKOM-Medica, Russia).

Disclosure of the invention.

We studied the effect of focal subthreshold microphotocoagulation on the dynamics of focal diabetic macular edema in patients with non-proliferative and preproliferative diabetic retinopathy. The dynamics of the thickness of the retina after laser irradiation was estimated using optical coherence tomography (Stratus coherence tomograph, Carl Zeiss (OST-3)). It was found that focal subthreshold microphotocoagulation leads to a significant reduction in macular edema in areas of local laser exposure, but does not prevent the occurrence of edema in areas where laser exposure was not performed (L. Chizh / Preliminary assessment of the effectiveness of diode laser microphotocoagulation of focal diabetic macular edema. Abstracts reports of the VIII Congress of Ophthalmologists of Russia, Moscow, 2005: 443). In addition, during the studies it was proved that subthreshold micropulse irradiation of the retina of the macula is comparable with suprathreshold laser treatment methods and does not cause deterioration of visual functions (central field of view) compared to suprathreshold laser coagulation, which improves the quality of vision and life of the patient ( Balashevich LI, Chizh L.V., Gatsu MV / Microphotocoagulation of focal and diffuse diabetic macular edema / Materials of the international conference “Laser-optic skie technologies in biology and medicine ": Minsk Institute of Physics, National Academy of Sciences 2004:. 107-111).

In order to overcome the disadvantages of suprathreshold laser coagulation, which causes significant damage in the central field of view of the patient, and focal subthreshold microphotocoagulation, which does not prevent the appearance of new foci of transudation in areas not exposed to laser irradiation, we developed a new microphotocoagulation method - pan-macular subthreshold microphotocoagulation. Which consists in the fact that with focal macular diabetic edema, subthreshold microphotocoagulation is carried out not only of the local zones of thickening of the retina, but also of the entire macular region (pan-macular) with the exception of the foveolar avascular zone, which reduces the risk of the appearance of new zones of transudation, and despite the increase in the laser zone exposure does not impair the central field of view of patients and their quality of life.

The implementation of the invention.

To implement the invention, it is necessary to use a laser system, which allows you to get a micropulse mode (IRIS Medical IQ 810 Laser System (IRIDEX, USA) and ALOD-01 (ALKOM-Medica, Russia). Edema zones are determined biomicroscopically and according to optical coherence tomography) Then, test retinal coagulation is performed in the areas of edema that are farthest from the center of the macula, using impulse packets of 0.2 s duration. Energy is selected until barely noticeable burns are seen, then the exposure is reduced to 0.1 s they carry out subthreshold microphotocoagulation, irradiating the retinal pigment epithelium under or in the immediate vicinity of the local transudation source (Fig. 1a). Subthreshold coagulates are placed at an interval equal to the coagulum diameter in two or more rows concentrically around the source of leakage within the entire zone of local retinal edema After that, the entire area of the macula free of edema is treated, and the coagulates are placed in the form of radial rows with an interval equal to the diameter of the coagulate, located paraffes eolarly with the capture of the edge of the avascular zone (Fig.1B).

Thanks to the use of the method for treating diabetic macular edema presented in the invention, we were able to obtain better results of the dynamics of macular edema and visual functions in comparison with the prototype (focal microphotocoagulation). Differences in retinal thickness and visual functions after various laser treatments are shown in FIGS. 2-4. As can be seen in the drawings, the proposed method has better efficiency compared to focal subthreshold microphotocoagulation and less trauma compared to the above threshold modified focal grating (Fig. 5).

Claims (1)

A method for treating the organ of vision of patients with diabetic macular edema, including subthreshold microphotocoagulation, characterized in that first they test retinal coagulation in the most distant parts of the edema using pulse packets of 0.2 s duration and select energy until there are barely noticeable burns after which the exposure is reduced to 0.1 s, then subthreshold microphotocoagulation is performed, and the retinal pigment epithelium is irradiated under or in the immediate vicinity of the source as a local transudation, and subthreshold coagulates are placed with an interval equal to the diameter of the coagulate in two or more rows concentrically around the source of seepage within the entire area of local retinal edema, after which the entire area of the macula is treated free of edema, and the coagulates are placed in the form of radial rows at intervals equal to the diameter of the coagulum, located parafoveal with capture of the edge of the avascular zone.

Images