**3. Experimental study 2**

The study was carried out on 40 cadaveric human eyes. In 14 cases, the vitreous body was stained by specialized contrast staining agent Vitreocontrast. The control group included the 14 eyes where Kenalog-40 suspension was instilled.

Simultaneous (comparative) contrast staining by Kenalog-40 + Vitreocontrast was performed in 12 cases.

Antegrade and retrograde dye injections were used.

In the control group, it was revealed that Kenalog-40 stains vitreous fibers but has a low-grade adhesion to the structural elements of the vitreous body. When Kenalog-40 was injected into the vitreous canals, it did not stay in their cavities. Vitreocontrast showed well-expressed adhesion to the VB structural elements (canals, cisterns, and their anastomoses), the degree of adhesion did not change with time. When injected in the projection area of VB canals, the dye settled on the walls of cisterns.

For the first time, a specialized contrast staining agent Vitreocontrast was developed, which due to its high mechanical adhesion, particle size, and intensive dye accumulation on VB structures made it possible to visualize not only VB fibers but also intravitreal channels, cisterns, and their relations.

One of the urgent issues of modern vitreoretinal surgery is intraoperative visualization of the vitreous body (VB), staining of its native structures and pathologically changed areas. The quality of the removal of transparent VB structures and the atraumatism of the intervention determine the anatomical and functional prognosis of the procedure. In this respect, the issue of VB structure undoubtedly remains important.

In 1973, J.Worst and Makhacheva Z.A. anatomical carried out functional studies of VB with the use of vital dyes that gave new understanding of its structure. Three rows of cisterns (the circle of equatorial, retrociliary and petaliform cisterns): canals (lentico-macular, optico-ciliary canal) and other VB structural elements were discovered and described [7]

Selection of perfect contrast staining agent still remains a topical problem due to the specific requirements (high dispersity, easy instillation and elimination, possibility of elimination via natural outflow ways, lack of side effects, etc.) imposed by surgeons.

Today, various vital dyes are used to identify the transparent structures of the posterior segment of the eye. These are triamcinolone acteonid (TA), trypan blue, *Perspective Chapter: The Vitreous Body Visualization Technique in Diagnosis… DOI: http://dx.doi.org/10.5772/intechopen.109264*

[34–36] membrane blue (0.15%), fluorescein, and indocyanine green [15, 21, 23, 37]. At the same time, none of the vital dyes allows for the antemortem identification of intravitreal structures described in the works by J. Worst [7].

A number of researchers showed that modern vital dyes due to their nonselective diffusion stained not only VB but the surrounding intraocular structures too, which impaired the identification of VB. Besides, the abovementioned agents have a number of side effects (cytotoxic, phototoxic, cataractgenic action, elevated intraocular pressure, and pharmacological activity) [6, 11, 15, 16].

Staining by TA is more effective because being not a true vital dye but a suspension it settles on VB as precipitates and VB can be easily distinguished from surrounding intraocular structures [22, 23, 38, 39]. That is why we chose this agent to stain VB in the control group.

The purpose of this study is to develop a specialized contrast staining agent for the intraoperative vitreous body structures visualization.

The study was carried out on 20 cadaveric human eyes. Researchers used specialized agent Vitreocontrast and triamcinolone acteonid or kenalog-40 to stain vitreous structures.

Preliminarily, VB was completely dissected from the overlying membranes (conjunctiva, sclera, choroid, and retina) (**Figures 6** and **7**).

In 14 cases, staining was performed by Vitreocontrast intravitreal injection.

The control group consisted of 14 eyes, in which kenalog-40 suspension was injected. Simultaneous (comparative) staining by Kenalog-40 + Vitreocontrast was performed in 12 cases.

Antegrade and retrograde methods of contrast staining agent injection were used.

We managed to stain the structures described in the works by J.Worst and Z.A. Makhacheva [7] staining VB structures with Vitreocontrast suspension retrograde injection. These were the circle of equatorial, petaliform and retrociliary cisterns, optociliary and lentico-macular canals, and premacular bursa (**Figure 8a–c**). Vitreocontrast showed pronounced adhesion to VB structural elements that did not change over time.

**Figure 6.** *The eyeball dissection. Sclera, choroid, and retina sequential removing.*

*Medical and Surgical Retina – Recent Innovation, New Perspective, and Applications*

**Figure 7.** *The eyeball after dissection.*

**Figure 8.**

*(a-d) Vitreal body structures contrasting by the Vitreocontrast suspension (retrograde injection). Equatorial cysterns (red arrows) and lenticular cysterns (black arrows), retrociliary cisterns (green arrows) earlier J. Worst described.*

The size of intravitreal structures was determined during the study (average size of retrociliary cisterns was 10–12 mm, equatorial cisterns were 15–17 mm, petal-like cisterns were 8–10 mm)

#### *Perspective Chapter: The Vitreous Body Visualization Technique in Diagnosis… DOI: http://dx.doi.org/10.5772/intechopen.109264*

When staining with Kenalog-40 antegrade injection in the projection of lenticomacular canal was used the walls of the canal were not clearly visualized, the vital dye did not stay in the canal cavity gradually settling into the posterior hyaloid (**Figure 9a–c**).

Under the comparative contrast staining of VB structures, Vitreocontrast was injected in the lentico-macular canal in the macular projection after the administration of kenalog-40 suspension. Vitreocontrast stained this canal, anastomoses with the cisterns surrounding it, and the premacular bursa (**Figure 9a–c**).

For the first time, a specialized contrast staining agent Vitreocontrast was developed, which due to its high mechanical adhesion, particle size, and intensive dye accumulation on more loose structures made it possible to visualize not only VB fibers but also intravitreal canals, cisterns, and their relations (**Figures 10–13**).

The new contrast staining agent is not toxic that allows us to recommend it for the further use in diagnosis and treatment of vitreoretinal diseases after its clinical approbation.

#### **Figure 9.**

*a. Kenalog-40 injection (anthegrade injection). b in the projection zone of lentico-macular the walls of the canal are not clearly visualized, the suspension settles in the VB hyaloid layers. c and d. Kenalog-40 particles settled on the vitreous cortical layers. The channels and ci sterns (their walls) not visualized. Retrograde administration of Kenalog-40 in the projection zone of lentico-macular canal, the walls of the canal are not clearly visualized, the suspension settles in the VB hyaloid layers.*

#### **Figure 10.**

*Vitreocontast suspension injection (red arrow) and Kenalog-40 injection (black arrow) in comparative vitreous structures contrasting.*
