No abstract

The contrast agents in vitreoretinal surgery are necessary to ensure the visualization of translucent and ultra-thin membranes and vitreoretinal interface (VRI) structures, but the ideal staining agent has not been found yet.Purpose. To investigate and compare staining properties of two vital dyes for vitreous body (VB) and vitreoretinal interface visualization: “Kenalog-40” and “Vitreocontrast”.Patients and methods. The study was performed on 20 cadaveric eyes. After eyeball dissection with the original technology, we carried out posterior vitreous cortex separation and comparative staining of retinal fragments on the side of VB and corresponding section of the VB by “Kenalog-40” and “Vitreokontrast”. Vitreo-retinal interface samples underwent morphological analysis.Results. In contrast to «Kenalog-40», «Vitreocontrast» enables the visualization of thin layer of VB on retina surface after splitting of cortical layers during posterior vitreous detachment induction. Upon that, the adherent particles of the “Vitreocontrast” suspension remained on the corresponding splitted fragment of the VB. After staining with “Kenalog-40”, the VB surface remained smooth, shiny, with no visible changes. The results of histological examination of the obtained retinal and VB samples confirmed the presence of VB layer on the retina surface at the site of vitreoshisis formation during the induction of posterior vitreous detachment.Conclutions. Received data confirm the possibility of vitreoshisis formation during posterior vitreous body detachment, and demonstrate the advantages of the staining properties of the “Vitreokontrast” suspension for visualization of fine structures of vitreoretinal interface.

The role of the vitreous body and vitreomacular interface (VMI) is key in many processes including proliferative diabetic retinopathy (PDR). In PDR patients, the VMI changes can significantly influence the emergence and progression of the disease. There are multiple factors at work in the VMI including taut posterior cortical layers, vitreoschisis, posterior vitreous detachment (PVD), and vitreous adhesions. But there is no general consensus about their role in proliferative complications. Further understanding the VMI relationship in a case of PDR is warranted in order to design better treatments, to arrest and possibly even reverse progression of PDR.  Today there is no imaging techniques to determine normal vitreous and VMI interactions in different PDR stages intraoperatively. Purpose: to analyze intraoperative vitreous and vitreoretinal interface features during chromovitrectomy in patients with A-C stages of PDR. Patients and methods. Seventy-four diabetic patients (74 eyes) were included. We performed standard 25 Gauge pars plana vitrectomy using Vitreocontrast for vitreous and vitreoretinal interface (VRI) visualization. Intravitreal “Vitreocontrast” suspension is the most favored agent of those studied and it is increasingly used as an adjunct during surgery to delaminate fine tissue planes and pockets of formed vitreous and VRI structures that may not be visible with routine operative illumination systems, or using modern vital dyes. Results. “Vitreocontrast” suspension allows to visualize posterior cortex changes during different stages of PDR. We investigated vitreous and VRI anatomy, topography and structure and determined safety of retrociliary and equatorial cisterns walls in 97 % in stage A of PDR, 95 % in stage B and in 82 % of stage C. In 3–5–18 % cases, correspondently, we determined disorganization of some vitreous cisterns. In 94 % cases of PDR A and 96 % cases of PDR B we visualized preretinal vitreous layer in a central macular zone, within the boundaries of vascular arcades. It has specific topography and strong adhesion to the internal retinal membrane. It’s the first time when this new vitreous cortex layer was revealed. The presence of this layer is the result of a strong vitreomacular adhesion that causes the posterior vitreous cortex split as it attempts to detach from the inner retinal surface. Such outermost layer remains attached to the macula and can induce further proliferation process. On a stage B of PDR this area correspond with multiple vitreoschisis, on a stage C of PDR — with fibrovascular membrane. The complete PVD was revealed in 61 cases. Conclusion. In this article we analyze the results of surgical treatment in 74 patients with A-C stages of proliferative diabetic retinopathy. Newer imaging technique with new dye — suspension “Vitreocontrast” allows to detect sensitive relationships of vitreous and VRI in each stage of the disease. The role of vitreous body in this process gives us a reason to consider it as an important object for further research. Moreover, the understanding of their relations in different stages of PDR enables to develop optimal surgical approach on each stage of PDR.

Methods and results of the developed vitreous body imaging technique in proliferative diabetic vitreoretinopathy diagnostics using new contrast dye during operation. The P. Kroll”s classification of proliferative diabetic retinopathy was modified after receiving new data about vitreoretinal interface structures during investigation using chromovitrectomy.

Purpose: The vitreous body (CT), due to the complexity of its structure, remains one of the least studied anatomical structures to this day. In the literature there are attempts to describe the anatomy of the vitreous body, since the II century. The most relevant works are the studies of J. Worst et al. in 1973, in which the authors proposed new methods of CT preparation with the introduction of dyes. Despite many years of research on the structure and functions of the vitreous body and the presence of a large number of works, and there are no methods and protocols for macromicroscopic examination of the vitreous body to develop a method and propose a protocol for macromicroscopic examination of the vitreous body (VB), allowing to obtain new data on VB topographic anatomy.Materials and methods. The proposed method of macromicroscopic examination was used to study the VB topographic anatomy of 38 cadaver eyeballs. In order to color transparent structures of the vitreous, poorly soluble metallic salts (barium sulfate and copper acetate) were used. Macroscopic examination was performed using a Topcon OMS-800 operating microscope with a magnification of ×8 to ×21, microscopic changes were evaluated by light microscopy at ×50, ×100, ×200, ×400, ×630 multiple magnification with Leica DM LB2 microscope followed by photographic recording. The algorithm for macroscopic examination performing.Results and discussion. The result of macroscopic preparation was the compilation of individual anatomical and topographic maps of patients. A distinctive feature of the developed method is the ability to dissect any VB structure and to isolate each cortical layer with the possibility of studying its anatomical and topographic features and relationships with underlying tissues (internal limiting membrane, ciliary body, lens capsule). In addition, the method allows to maintain the shape and integrity of the specimens after passing through all stages of histological processing. In order to fixate VB samples, we used a method with fixing VB structures on a special adhesive-metric tablet, and placing them in a biopsy bag placed in a biopsy cassette. After that, filled in formalin, the specimens were delivered to the laboratory, where all the stages of standard processing took place.Conclusion. The developed technique of macromicroscopic examination of the vitreous allows to create an individual map of the VB topographic anatomy. After collecting of sufficient material and its statistical processing, it is possible to provide maps of the VB topographic anatomy in normal, age-related and pathological conditions.