Офтальмохирургия (Jan 2021)
Macro-microscopic study of posterior vitreous detachment variants in an ex vivo experiment
Abstract
Purpose. The key to understanding the development of any vitreoretinal pathology is a presence of a clear conception to possible variants of changes in the anatomical and topographic relationships of the posterior cortical layers of the vitreous body and the retinal internal limiting membrane (ILM) in a formation of posterior vitreous detachment (PVD).An original method of macro-microscopic examinations of anatomical objects proposed by professor V.P. Vorobyov, which includes investigations of morphological objects whose dimensions lie in the boundary area between macroscopic parameters studied by anatomists and microstructures studied by histologists, discover a new boundary area for the study of anatom ical structures.However, it has not been practically used in ophthalmology until now. The study of a process for changes in the vitreoretinal interface during the PVD occurrence is difficult due to a complexity of simulation, a possibility of visualization, and an absence of approved protocols for macro-microscopic research.Purpose. To study variants of anatomical and topographical changes in the vitreoretinal interface during the formation of induced PVD in ex vivo experiments using the method of macro-microscopic examination.Material and methods. The study was performed in 24 eyeballs of cadaver donors. To assess changes in the vitreoretinal interface in the process of PVD induction, an original method of dissection was used, that allows to isolate layer-by-layer the cortical layers of the vitreous body and the retinal ILM, with a possibility of further evaluation of changes in the vitreoretinal interface by the macro-microscopic examination. Salt barium sulfate suspension Video-contrast was used with the purpose to contrast vitreous fibers. Macroscopic investigation was carried out using the Topcon OMS-800 operating microscope with an indication from x8 to x21 magnification, microscopic changes were evaluated by the light microscopy method with x50, x100, x200, x400 x630 magnification using the Leica DM LB2 microscope with the subsequent photo r egistration.Results. During the macro-microscopic study, three variants of possible changes in the vitreoretinal interface during the development of induced PVD were revealed, which were interpreted as the normal (true) PVD and abnormal PVD, which occurred both with the formation (the variant A) of vitreoschisis zones (exfoliation of the cortical layers of the vitreous body) and with the zones of retinal ILM exfoliation (the variant B).Conclusion. The proposed method of macro-microscopic investigation of the vitreoretinal interface allows to dissect isolated sequentially layerby- layer the cortical layers of the vitreous body and the retinal ILM with subsequent fixation on a special substrate according to the original method and the possibility to carry out a histological section and its evaluation by the light m icroscopy method. The application of the developed method allows to accurately assess changes in the vitreoretinal interface on any isolated site of the vitreoretinal surface. The presented work demonstrates possibilities for the application of the method to detect variants of changes in the vitreoretinal interface within the formation of i nduced PVD.
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