Vitreous constitutes about 80% of the volume of the human eye. It is an extended extracellular matrix that is composed of collagen, hyaluronan, and other extracellular matrix molecules, but mostly water. In both health as well as disease, especially diabetic retinopathy (DR), special attention should be drawn to the posterior vitreous cortex and its relation to the retinal surface. The importan...

PURPOSE To investigate the possibility of using polylactic acid (PLA) as a surgical adjuvant for visualizing the vitreous body during vitrectomy. METHODS After a core vitrectomy, 1 mL of PLA suspension was injected into the rabbit vitreous in two groups: group A, 2.5% PLA (n = 5), and group B, 1% PLA (n = 9). Vehicle injection instead of PLA was used as a control (group C, n = 5). The clinica...

PURPOSE The aim of this study was the assessment of vitreous humor as a potential DNA for forensic human postmortem identification. MATERIAL AND METHODS Vitreous humor samples were collected using two alternative approaches from 25 corpses of either sex during autopsies. DNA was extracted by standard organic method. Recovered DNA was quantitiated fluorometrically. AmpFlSTR SGM Plus kit and AB...

Ethanol concentrations in postmortem blood and vitreous humor samples collected at the Miami-Dade Medical Examiner Department over 5-6 years ago were reexamined to assess whether vitreous humor is a more reliable specimen for the analysis of ethanol in samples stored long term. The average change in 50-mL polypropylene tubes containing blood was 0.06 gm/dL (35% loss). On the other hand, vitreou...

Ocular ischemic microenvironment plays a critical role in the progression of diabetic retinopathy (DR). In this study, we investigated the effect of vitreous and aqueous obtained from proliferative DR patients on the function of CD34⁺ cells derived from healthy humans. Human CD34⁺ cells were incubated with vitreous or aqueous of subjects with PDR. After incubation, cell migration of CD34⁺ was e...

PURPOSE The aim of this study was to evaluate the relationship between oxidative stress and human vitreous degeneration, using the presence of an evident posterior vitreous detachment (PVD) as a clinical sign and thiobarbituric acid-reactive substances (TBARS) and nitrite as oxidative biomarkers. METHODS We collected 42 vitreous samples from patients undergoing pars plana vitrectomy for two g...

The aim of the study is to clarify the vitreous body structure and liquefaction phenomena. It was found that when melting a frozen rabbit vitreous body, the gel-sol transition phenomenon occurs and the gel structure is broken. This is almost like the liquefaction of the vitreous body in vivo. We try to clarify the liquefaction phenomenon by using this animal model. The native vitreous body has ...

PURPOSE To investigate whether enzymatic collagen breakdown is an active process in the human vitreous. METHODS Human donor eyes were used for immunohistochemistry to detect the possible presence of the matrix metalloproteinase (MMP)-induced type II collagen breakdown product col2-3/4C-short in the vitreous. Western blot and slot blot analyses were used to further identify vitreal type II col...

Although vitreous is the largest structure within the eye, constituting 80% of the ocular volume, investigators of vitreous anatomy are hampered by two fundamental diffi culties: ● Any attempts to defi ne vitreous morphology are efforts to “visualize” a tissue that is invisible by design ( Fig. 6-46-1 ). ● The various techniques that were employed previously to defi ne vitreous structure were f...