Methods of treatment of macular edema in Israel
The invention relates to the field of medicine, andnamely to ophthalmology, and can be used in the laser treatment of diabetic macular edema. Affect the entire field of diabetic macular edema, located inside the vascular arcades. Laser radiation with a wavelength of 0.81 μm, a pulse duration of 0.2 s, a spot diameter of 100 μm is used. Irradiation of the fundus is almost draining - the interval between laser applications is 0-1 diameter of the irradiation spot. The laser radiation power is selected until a minimal burn occurs on the most pigmented area of the irradiated tissue after 1-2 of 10 laser exposures. The method makes it possible to improve the results of laser treatment of this pathology without the risk of atrophy of the membranes of the fundus and a decrease in the sensitivity of the retina due to an increase in the total area of exposure due to very dense or confluent application of laser applications with subthreshold parameters of exposure.
The invention relates to the field of medicine, namely to ophthalmology, and can be used in the laser treatment of diabetic macular edema.
To date, laser treatment withDiabetic macular edema (DMO) is the most common and effective method of preventing a patient's vision from being disabled. Indications for this treatment method and general requirements for the method of its implementation are set forth in the protocols of a large-scale ETDRS study (1985-1997), which confirmed the clinical effectiveness of the modified "mETDRS" with ETM (ETDRS report number 19. Early treatment diabetic retinopathy study group, Focal photocoagulation, treatment of diabetic macular edema, Arch Ophthalmol .-- 1995. - Vol.113, No. 9. - P.1144-1155).
According to the conclusion of a multicenter study http://DRCR.net (Fong DS, et al, Comparison of the modified Early Treatment Diabetic Retinopathy Study and mild macular grid laser photocoagulation strategies for diabetic macular edema // Arch Ophthalmol .- 2007. - Vol.125 (4), - P .469-80), the anti-edema effect of laser coagulation directly depends on the severity of coagulation damage. It is on this basis that http://DRCR.net (2007) concludes that today the standard for the treatment of diabetic macular edema remains a modified "lattice" of ETDRS.
However, the use of this technique is associated with the inevitable occurrence in the long term of deep atrophy of the membranes of the fundus and a significant decrease in the sensitivity of the retina.
However, in 1993 J. Roider et al. (Rober J. Laser treatment, Semin Ophthalmology .- 1999.-Vol.14, -P.19-26.) Proposed the use of microphotocoagulation for the treatment of DME, which is free from the aforementioned lack of laser coagulation. This technique (MicroPulse mode, laser wavelength 0.8 μm, spot diameter 100 μm, pulse duration 0.1-0.2 s with a duty ratio (ratio between micropulse and micropause in the pulse brush) is 5-50%, laser burns are applied radially around the center of the macula with an interval of 1-3 the diameter of the irradiation spot (about 100-200 applications) is positioned as subthreshold coagulation of the retina, since the laser radiation power does not reach the level of biomicro- scopically visible coagulation whitening of the retina. aliens give (Ciz LV, MV Gatsu et al. 2004-2008.) MicroPulse has comparable with traditional laser coagulation effect on macular edema regression without causing atrophy of tissues in the irradiation area.
The disadvantage of this technique, as well astraditional "lattice", is a limited number of applications and a small area of laser exposure. Later studies by D. Lavinsky et al. (Daniel Lavinsky et al., Randomized clinical trial evaluating mETDRS versus normal or high-density micropulse photocoagulation for Diabetic Macular Edema, Invest Ophthalmol Vis Sci 52 (7): 4314-23 (2011) PMID 21345996) indicate an increase in the effectiveness of microphotocoagulation in more dense deposition of subthreshold retinal burns.
With microphotocoagulation is technically possibleselect the laser power (near-subthreshold level), at which in the long term there is no atrophy of the membranes of the fundus. This makes it possible to be more dense than D. Lavinsky et al. (2011), confluent (no gaps) application of laser applications in one treatment session without the risk of getting cattle in the patient's field of vision, as evidenced by threshold autoperimetry data.
Our studies have shown that whenof the same average laser power, the conduct of near-subthreshold laser treatment both in the continuous mode of operation and in microphotocoagulation has an equal effect on the visual acuity of the patient, the maximum height and the area of the diabetic macular edema.
The aim of the invention is to improve the results of laser treatment of diabetic macular edema.
The essence of near-subthreshold laser treatmentis to enhance the stimulating effect of laser treatment on the pigment epithelium of the retina by increasing the total area of the action due to very dense or confluent application of laser applications in near-subthreshold parameters of laser radiation.
High-density laser coagulation is carried outdiode laser - wavelength 0.81 μm, pulse duration 0.2 s, irradiation spot diameter 100 μm, interval between laser applications at 0-1 irradiation spot diameter. The radiation power of the laser is selected until a minimal burn occurs on the most pigmented area of the irradiated tissue after 1-2 of 10 laser exposures (mainly subthreshold radiation). Laser applications are performed only within the retinal edema in the posterior pole of the eye (within the vascular arcade).
The near-subthreshold character of coagulation allowssignificantly increase the number of applications (up to 1000 or more) without the risk of reducing visual acuity and the risk of postcoagulant atrophy of the ocular fundus, typical of the traditional over-threshold coagulation, which has a negative impact on the patient's central field of vision. The stimulating effects of the laser are mainly melanin granules in the cells of retinal pigment epithelium.
Method of laser treatment of diabeticmacular edema, characterized by the fact that the entire field of diabetic macular edema inside the vascular arcades is applied, laser radiation with a wavelength of 0.81 μm, a pulse duration of 0.2 s, a spot diameter of 100 μm is used, and the irradiation of the fundus is practically draining character - the interval between laser applications in the 0-1 diameter of the irradiation spot, and the laser radiation power is selected until a minimal burn occurs on the most pigmented area of the irradiated tissue after 1-2 of 10 laser exposures.