Clinicopathological changes at the vitreoretinal junction: posterior vitreous detachment

Abstract

Separation of the vitreous and posterior hyaloid membrane (PHM) or posterior vitreous detachment (PVD) typically occurs between the ages of 45 and 65 years in the general population, but may occur earlier in myopic or otherwise predisposed individuals. Age-related synergetic changes occurring within the cortical and central gel must be distinguished from the PHM, which envelopes it. This study reports on the correlation between 'true' PVD seen clinically by the physician using dynamic examination, high-power slitlamp biomicroscopy, and oblique illumination with some of its histological, immunohistochemical, and ultrastructural features post-mortem. The presence of the Weiss ring does not necessarily indicate total clean separation of PHM, nor does its absence confirm that the PHM remains attached, since it may be destroyed during the process of separation. Immediately prior to PVD with the vitreous gel attached, the PHM must, by definition, form part of the inner limiting membrane. The detached PHM frequently exhibits basement membrane (BM) and its indigenous laminocytes stain focally for GFAP and type IV collagen. The PHM is distinct from and much thicker than the BM of Mü ller cells alone and the factors that initiate or limit separation of the PHM require greater study, particularly the role of laminocyte proliferation and migration.

Rhegmatogenous Retinal Detachment: A Reappraisal of Its Pathophysiology and Treatment

“…Vitreoretinal surgeons have only rather recently realized [19] that, despite the biomicroscopic findings reported previously [23], what appears to be a PVD is not necessarily that. While, using careful biomicroscopic techniques, a PVD prevalence of 72% in the 7th and a 100% rate in the 8th decade has been described in highly myopic eyes [24], the vitreoretinal surgeon almost never finds true PVD in these eyes.…”

“…The separation is not necessarily complete or uniform, and detachment of the (posterior) vitreous can be present in one area but absent adjacent to it [18]. It is a common error to equate the presence of a Weiss ring with the presence of a posterior vitreous detachment (PVD) [19]. Despite a Weiss ring that is clearly visible at the slit lamp, however, the vitreous may still be attached to the retina elsewhere.…”

Reply

“…Although suggested that cellular infiltrates at the internal limiting membrane or posterior vitreous may have a function in rhegmatogenous retinal detachment pathogenesis, to date, the role of laminocytes at the posterior hyaloid membrane is incompletely understood. 4 There remains a significant amount of genetic, biochemical, and histopathological work to be done before we completely understand the structural and age-related changes in the vitreous and at the vitreoretinal interface and their role in predisposition to retinal tear formation during posterior vitreous detachment. The concept of a unifying adhesive "glue" between the vitreous and the retina that is disrupted during posterior vitreous detachment is perhaps an oversimplified representation, as the dynamic process of vitreoretinal adhesion is likely to involve a more complex interplay of a network of many factors.…”

The Incidence of Retinal Breaks in the Presenting and Fellow Eyes in Patients With Acute Symptomatic Posterior Vitreous Detachment and Their Associated Risk Factors

“…1 The floaters can represent blood in the vitreous cavity, condensed vitreous gel, or a glial remnant from around the optic nerve. 1 The floaters can represent blood in the vitreous cavity, condensed vitreous gel, or a glial remnant from around the optic nerve.…”