TWENTY-FIVE GAUGE ULTRASONIC VITRECTOMY: Experimental and Clinical Performance Analysis

The rabbits retina functional state after exposure to low-frequency ultrasound: electroretinogram indicators analysis

Relevance. Currently, several groups of scientists are working on the implementation of low-frequency ultrasound in surgery of the retina and vitreous body. But there are not enough articles on the study of the functional activity of the retina when exposed to this type of energy. Electrophysiological research methods make it possible to analyze and evaluate the safety, effectiveness of surgical interventions, the effect of new drugs at the level of neurons and visual pathways. The electroretinography method makes it possible to record the bioelectrical activity of retinal neurons during light stimulation during dark and light adaptation. The aim of the study is to carry out a comparative analysis of the aand b-wave indices of the rabbit electroretinogram after experimental removal of the vitreous body using low-frequency ultrasound and mechanical action. Materials and Methods. Experiments were carried out in two groups of Chinchilla rabbits (n = 40). In the experimental group, surgery to remove the vitreous body was performed using low-frequency ultrasound, in the control group a fragmentator with guillotine mechanism was used. Before and after the surgery (1, 7, 14, 30 days) an electroretinogram was recorded, the parameters of the amplitude and latency of the aand b-waves were measured. Results and Discussion. In both groups, a sharp decrease in all parameters was observed on day 1. Later, on the 7th day, the dynamics of the latency of aand b-waves slightly decreased than the preoperative values. On the 14th day after the exposure, the amplitude and peak latency of the aand bwaves in both groups remained at the same level as on the 7th day. On the 30th day, the indicators increased, which indicates the restoration of the functions of photoreceptors and Mueller cells in both groups. There were no statistically significant differences between the study groups at all periods of the study. Conclusion. The use of low-frequency ultrasound for vitreous removal can be considered safe and has prospects for further development and application.

The rabbits retina functional state after exposure to low-frequencyultrasound: electroretinogram indicators analysis

Relevance. Currently, several groups of scientists are working on the implementation of low-frequency ultrasound in surgery of the retina and vitreous body. But there are not enough articles on the study of the functional activity of the retina when exposed to this type of energy. Electrophysiological research methods make it possible to analyze and evaluate the safety, effectiveness of surgical interventions, the effect of new drugs at the level of neurons and visual pathways. The electroretinography method makes it possible to record the bioelectrical activity of retinal neurons during light stimulation during dark and light adaptation. The aim of the study is to carry out a comparative analysis of the a- and b-wave indices of the rabbit electroretinogram after experimental removal of the vitreous body using low-frequency ultrasound and mechanical action. Materials and Methods. Experiments were carried out in two groups of Chinchilla rabbits (n = 40). In the experimental group, surgery to remove the vitreous body was performed using low-frequency ultrasound, in the control group a fragmentator with guillotine mechanism was used. Before and after the surgery (1, 7, 14, 30 days) an electroretinogram was recorded, the parameters of the amplitude and latency of the a- and b-waves were measured. Results and Discussion. In both groups, a sharp decrease in all parameters was observed on day 1. Later, on the 7th day, the dynamics of the latency of a- and b-waves slightly decreased than the preoperative values. On the 14th day after the exposure, the amplitude and peak latency of the a- and b-waves in both groups remained at the same level as on the 7th day. On the 30th day, the indicators increased, which indicates the restoration of the functions of photoreceptors and Mueller cells in both groups. There were no statistically significant differences between the study groups at all periods of the study. Conclusion. The use of low-frequency ultrasound for vitreous removal can be considered safe and has prospects for further development and application.