CHAPTER 10
Vitreous
Topography
The vitreous humor makes up most of the volume of the globe and is important in many diseases that affect the eye. BCSC Section 12, Retina and Vitreous, discusses the vitreous in detail.
The average volume of the adult vitreous is 4 mL. The vitreous is composed of 99% water and several macromolecules, including
types II and IX collagen glycosaminoglycans soluble proteins glycoproteins
The outer portion of the vitreous has a greater number of collagen fibrils and is termed the vitreous cortex. The outer surface of the cortex is known as the hyaloid face.
The vitreous is bordered anteriorly by the lens, where its attachment to the lens capsule is called the hyaloideocapsular ligament. This attachment is firm in young patients and becomes increasingly tenuous with age. The vitreous is attached to the internal limiting membrane (ILM) of the retina by the insertion of the cortical collagen into the basement membrane structure that comprises the basal lamina of the ciliary epithelium and the ILM.
The vitreous attaches most firmly to the vitreous base, a 360° band that straddles the ora serrata and varies in width from 2 to 6 mm. The vitreous base extends more posteriorly with advancing age. Other relatively firm attachments of the vitreous are
at the margins of the optic nerve head along the course of major retinal vessels in a circular area around the fovea
at the edges of areas of vitreoretinal degeneration such as lattice degeneration
The strength of the vitreoretinal attachment is important in the pathogenesis of retinal tears and detachment, macular hole formation, and vitreous hemorrhage from neovascularization.
Figure 10-1 Persistent fetal vasculature. Note the prominent anterior fibrovascular plaque (arrowhead). The posterior remnant of the persistent hyaloid artery is evident at the optic nerve head (arrow).
Figure 10-2 A, Gross photograph of opacification and infiltration of the vitreous as a result of bacterial endophthalmitis. B, Section shows cellular infiltration of vitreous in endophthalmitis (retinal detachment is artifactitious). (Courtesy of Hans E.
Grossniklaus, MD.)
Figure 10-3 Gross photograph of vitreous condensations outlining syneretic cavities. (Courtesy of Hans E. Grossniklaus, MD.)
Figure 10-4 Gross photograph of posterior vitreous detachment. (Courtesy of Hans E. Grossniklaus, MD.)
Figure 10-5 A, Gross photograph of retinal tears at vitreous base. B, Photomicrograph shows condensed vitreous (arrow) attached to anterior flap of retinal tear. (Courtesy of W. Richard Green, MD.)
Figure 10-6 Long-standing total retinal detachment with macrocystic degeneration of the retina.
Figure 10-7 Preretinal membrane (between arrows) on the surface of the retina, secondary to proliferative vitreoretinopathy.
(Courtesy of David J. Wilson, MD.)
Figure 10-8 Macular holes. A, Spectral domain OCT showing stage 3 macular hole with full-thickness retinal defect, rounded margins, cystoid macular edema (asterisks), and operculum (arrowhead). Note the posterior hyaloid face (arrow) tethered to the peripapillary retina near the optic disc. B, Gross photograph of full-thickness macular hole (arrow). C, Histology of fullthickness macular hole showing rounded gliotic margin (arrow) with positive staining for glial fibrillary acidic protein (GFAP),
highlighting the Müller cells and fibrous astrocytes. (Parts A and B courtesy of Robert H. Rosa, Jr, MD, and Terry Hanke, CRA; part C courtesy of Patricia Chévez-Barrios, MD.)
Figure 10-9 A, Clinical photograph of retrolental hemoglobin spherules. B, Cytologic preparation of hemoglobin spherules
removed from the vitreous cavity. (Reproduced with permission from Spraul CW, Grossniklaus HE. Vitreous hemorrhage. Surv Ophthalmol. 1997;42(1):3–39.)
Figure 10-10 Asteroid bodies (arrows) and erythrocytic debris within the vitreous. (Courtesy of Tatyana Milman, MD.)
Figure 10-11 Electron photomicrograph shows characteristic amyloid fibrils. (Courtesy of David J. Wilson, MD.)
Figure 10-12 Polarized light photomicrograph of the Congo red–stained vitreous from a patient with familial amyloid
polyneuropathy. (Courtesy of David J. Wilson, MD.)
Figure 10-13 Perivascular sheathing (arrow) associated with vitreous amyloidosis. (Courtesy of Hans E. Grossniklaus, MD.)
Figure 10-14 Sub-RPE infiltrates in a patient with primary intraocular lymphoma. Note the characteristic speckled pigmentation over the tumor detachments of the RPE.
Figure 10-15 Cytologic preparation of vitreous lymphoma. Note the atypical cells (arrowheads) with large nuclei and multiple nucleoli. Cell ghosts (arrows) are also present.
Figure 10-16 Primary intraocular lymphoma. Note the detachment of the RPE by tumor (arrow) overlying retinal gliosis (asterisk), and intact Bruch membrane (arrowhead). Secondary chronic inflammation is present in the choroid. (Courtesy of
Robert H. Rosa, Jr, MD.)
The embryologic development of the vitreous is generally divided into 3 stages:
1.primary vitreous
2.secondary vitreous
3.tertiary vitreous
The primary vitreous consists of fibrillar material; mesenchymal cells; and vascular components: the hyaloid artery, vasa hyaloidea propria, and tunica vasculosa lentis (see Fig 3-3 in BCSC Section 11, Lens and Cataract). The secondary vitreous begins to form at approximately the ninth week of gestation and is destined to become the main portion of the vitreous in the postnatal and adult eye. The primary vitreous atrophies with formation of the secondary vitreous, leaving only a clear central zone through the vitreous (called the hyaloid canal, or the Cloquet canal) and, occasionally, the Bergmeister papilla and Mittendorf dot as vestigial remnants (discussed later). The secondary vitreous is relatively acellular and completely avascular. The cells present in the secondary vitreous