First Author: N.Umanets UKRAINE
Co Author(s): N. Pasyechnikova U. Vadim M. Eduard G. Levitskaya R. Nazaretyan R V. Zavodnaya 0 0 0 0 0 0 0 0 0
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Purpose. To evaluate the structural changes of chorioretinal complex in rabbit immediately after exposure of different modes of high-frequency electric welding of biological tissues (HFEW) compared with a threshold diode endolaser coagulation.
Settings. Experimental, comparative, nonrandomized study.
Material and methods. For the pilot study were selected 7 rabbits (14 eyes). Experimental animals were divided into 4 groups - 3 main (2 rabbits in each group) and one control group (1 rabbits). In the first experimental group (2 rabbits (4 eyes)) we used threshold parameters for HFEW of chorioretinal complexes voltage - 14-16 V, current up to 0.1 A, exposure - 1-2 seconds, frequency - 66 kHz. In the second experimental group (2 rabbits (4 eyes)) retinopexy performed by voltage 18-20V. Another parameters of electric current were the similar. In the third group of the experimental animals (2 rabbits (4 eyes )) chorioretinal adhesion formed by laser irradiation with a wavelength of 810 nm (E = 200-300 mW, t = 250 msec) using a endovitreal probe. Rabbit in the control group was not carried out any interventions. Enucleated eyes were fixed in Carnoy's solution, embedded in «Gistomiks» (Biovitrum, Russia). Sections were stained with hematoxylin and eosin and were examined by light microscopy.
Results. The more destructive effect has a threshold diode endolaser coagulation, which was accompanied by coagulation changes of all layers of the retina and reactive changes of choroid (plasmorrhages). Less destructive effects has HFEW by parameters voltage - 18-20 V, current – up to 0.1 A, 66 kHz frequency (distortion of the structure of all layers of the retina. Delamination of ganglion cells layer and the inner plexiform layer was observed. Coagulation changes were observed in the outer parts of the inner plexiform layer). More safety influence has HFEW by parameters: voltage - 14-16 V, current - 0.1 A, frequency - 66 kHz, which accompanied by edema of the inner plexiform and ganglion cell layers of the retina, some architectonic changes of photoreceptors layer. The changes of external and internal nuclear layers were minimal and manifested with some cytoarchitectonic violation, which can be explained by edema of these layers. Reaction of the choroid was not observed.
Conclusion. Most gentle effects on chorioretinal complex of rabbit has a high-frequency electric welding of biological tissue by parameters of electric current voltage - 14-16 V, current - 0.1 A, frequency 66 kHz. We expect that the high-frequency electric welding of biological tissues can be considered as an alternative method of retinopexy with the ability to minimize the destructive effects on the retina.