The vitreous is an optically clear extracellular matrix that fills the inside of the eye. It can be divided into several substructures, including the anterior hyaloid behind the lens, the vitreous base at the anterior retina, the vitreous cortex forming an elastic shell and the vitreous core in the center. To dissect the vitreous, we first need to remove the anterior segment.
A super sharp blade is used to incise the cornea at the limbus. Then cornea scleral scissors are used to cut the cornea just anterior to the limbus. The iris is dissected with curved scissors by pulling it from its face.
Gentle pressure on the globe can expul the nucleus. To remove the vitreous core, use a 23 gauge needle on a five cc syringe and aspirate the mostly liquid vitreous. The anterior hyaloid becomes visible as a thin transparent membrane structure that can be grasped with forceps.
It's an elastic structure just behind the lens. The inner circle is wit's ligament. Van scissors are used to cut the hyaloid while forceps apply traction.
Lat tissue can be transferred to afu tube and the maneuver is repeated until all the tissue has been dissected. To access the remaining vitreous substructures, it is necessary to open the eye using curved westcott scissors. Each of the flaps are averted with forceps in a Petri dish.
This image shows the anatomy of the vitreous base, a thin, transparent tissue that straddles the aura serrata. The aura serrata the dividing line between the ciliary body anteriorly and the retina posteriorly. Unlike other parts of the vitreous, the vitreous base is firmly adherent to the underlying ciliary body and retina pulling with forceps will actually elevate the tissue.
To isolate the vitreous base, we first remove the pars plata using forceps and wescott scissors. The pars plata is this small area with ridges. Then to isolate the vitreous base, cut two to three millimeters posterior to the aura with westcott scissors while stabilizing the eye with forceps, hold and put traction on the vitreous base using forceps and cut sequentially with westcott scissors.
There's a string of pearls appearance as the vitreous base is excised and it can be observed how this extracellular matrix might compartmentalize proteins. Different techniques can be used to dissect the shell of the vitreous. Contact with a WEX cell sponge will elevate the cortex.
An edge of cortex can be found between the leaflets as shown here. Again, use the forceps to create traction and find VanNess scissors to sequentially cut the vitreous cortex. The cortex can also be elevated off the disc and here larger westcot scissors are used to to dissect the cortex as it is carefully peeled off the surface of the retina.
Samples can then be placed in a micro and stored for later proteomic analysis.
