SymptomsVitreous haemorrhage normally occurs suddenly, and without any pain. Symptoms range from the sudden appearance of spots or floaters in your vision, to a sudden blurring of vision, and in severe cases, sudden blindness.Some people find that their vision tends to be worse in the morning, as the blood has settled to the back of their eye during the nightCausesThere are three main causes of vitreous haemorrhage:Damage to normal blood vesselsRetinal blood vessels that are damaged through injury or trauma can cause a vitreous haemorrhage. Some eye problems can also cause damage to the blood vessels of the retina, such as retinal tears. A retinal vein occlusion can also cause vitreous haemorrhage, as it blocks the veins that feed the retina, which may then bleed into the vitreous ‘gel’.Growth of abnormal blood vesselsSome eye conditions can cause the growth of abnormal blood vessels that bleed into the vitreous ‘gel’ of the eye. The later stages of diabetic retinopathy, some retinal vein occlusions, and occasionally wet AMD can cause abnormal, delicate blood vessels to grow and bleed into the vitreous cavity.Bleeding from other parts of the eyeOccasionally, blood from another source can cause a vitreous haemorrhage. While it is very rare, a haemorrhage in another part of the eye, or even a tumour, can cause blood to leak through into the vitreous ‘gel’.TreatmentVitreous haemorrhage sometimes goes away by itself, or it can be removed with vitrectomy surgery, which may also be required to treat the cause of the haemorrhage.

Eye floaters are spots in your vision. They may look to you like black or gray specks, strings, or cobwebs that drift about when you move your eyes and appear to dart away when you try to look at them directly. Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid. 4 beds, 4 baths, 3836 sq. House located at 8461 Grand Canal Dr, Miami, FL 33144 sold for $545,000 on Jun 24, 2003. View sales history, tax history, home value estimates, and overhead views.

Treuting, in, 2018 HistologyThe vitreous chamber appears empty as a result of its high water content. The vitreous chamber’s exterior surface, known as the anterior hyaloid face, is behind the lens, whereas the posterior hyaloid face lies just anterior to the retina.

The vitreous is firmly attached at the vitreous base located at the ora serrata. Additional firm attachments exist at the optic nerve head, overlying retinal vessels, and near the human fovea.The lens epithelium is a monolayer of cuboidal cells located just below the anterior and equatorial lens capsule where the cells are columnar. The lens epithelial cells located at the lens equator continue to divide and produce lens fibers throughout life, with mitotic figures sometimes present. Epithelial cells are not present posterior to the lens equator under normal conditions. The central lens fibers, which are the oldest lens fibers, lack nuclei and have few intracellular organelles. Lee Ann Remington OD, MS, FAAO, in, 2012 Vitreous ChamberThe vitreous chamber is filled with the gel-like vitreous body and occupies the largest portion of the globe. It is bounded on the front by the posterior surface of the lens and the retrozonular portion of the posterior chamber.

Peripherally and posteriorly, it is bounded by the pars plana of the ciliary body, the retina, and the optic disc. All surfaces that interface with the vitreous are basement membranes. The center of the anterior surface contains the patellar fossa, an indentation in which the lens sits. The vitreous makes up about 80% of the entire volume of the eye. Vitreal AttachmentsThe vitreous forms several attachments to surrounding structures.

The strongest of these is the vitreous base, located at the ora serrata. The other attachments (in order of decreasing strength) are to the posterior lens, to the optic disc, at the macula, and to retinal vessels. Vitreous relationships in the anterior eye.Ora serrata ( 1) is termination of retina. Vitreous base ( 2) extends forward approximately 2 mm over ciliary body and posteriorly approximately 4 mm over peripheral retina.

Collagen in this region is oriented at a right angle to surface of retina and ciliary body, but anteriorly over pars plana, it is more parallel to inner surface of ciliary body. Posterior hyaloid ( 4) is continuous with retina and anterior hyaloid ( 3) with zonules and lens. Also depicted are hyaloideocapsular ligament ( 5) and space of Berger ( 6). (From Hogan MJ, Alvarado JA, Weddell JE: Histology of the human eye, Philadelphia, 1971, Saunders.)The hyaloideocapsular ligament (of Weiger), or retrolental ligament, forms an annular attachment 1 to 2 mm wide and 8 to 9 mm in diameter between the posterior surface of the lens and the anterior face of the vitreous.

60 This is a firm attachment site in young persons, but the strength of the bond diminishes after age 35. 62 Within the ring formed by this ligament is a potential space, the retrolental space (of Berger), which is present because the lens and vitreous are juxtaposed but not joined. 2The peripapillary adhesion around the edge of the optic disc also diminishes with age.

The annular ring of attachment at the macula is 3 to 4 mm in diameter. 2The attachment of the vitreous to retinal blood vessels consists of fine strands that extend through the internal limiting membrane to branch and surround the larger retinal vessels. 61,63 These strands may account for hemorrhages that occur when there is vitreal traction on the retina.

The nature of the attachment between the vitreous and the retinal internal limiting membrane throughout the rest of the retina remains uncertain. It is unlikely that fibrils from the posterior vitreous insert into the internal limiting membrane. 64-66 But rather the vitreoretinal interface contains a “molecular glue” linking the outer part of the cortex and the inner part of the limiting membrane. 2,67,68 This area contains extracellular matrix—molecules, including laminin and fibronectin, that have been identified as having adhesive properties. 62 Vitreous ZonesThe vitreous can be divided into zones that differ in relative density. The outermost zone is the vitreous cortex, the center zone is occupied by Cloquet’s canal, and the intermediate zone is inner to the cortex and surrounds the center canal. Vitreous CortexThe vitreous cortex, also called the hyaloid surface, is the outer zone.

69 It is 100 μm wide, 2 and it is composed of tightly packed collagen fibrils, some of which run parallel and some perpendicular to the retinal surface. 70,71 The anterior cortex lies anterior to the base and is adjacent to the ciliary body, posterior chamber, and lens.

The posterior cortex extends posterior to the base and is in contact with the retina. It contains transvitreal channels that appear as holes—the prepapillary hole, the premacular hole, and prevascular fissures.

The prepapillary hole can sometimes be seen clinically when the posterior vitreous detaches from the retina. 60 The premacular hole, a weak area, may be a region of decreased density rather than an actual hole. 60,71 The prevascular fissures provide the avenue by which fine fibers enter the retina and encircle retinal vessels. 61 Intermediate Zone. Eisner’s interpretation 71 of vitreous structures (according to slit-lamp examinations of eyes obtained at autopsy). Vitreous body is divided into three zones: Externally, as far as retina extends, there is a relatively thick vitreous cortex (light orange). It has holes at characteristic locations: in front of papilla, in region of fovea centralis, in front of vessels, and in front of anomalies of ora serrata region (enclosed ora bays, meridional folds, zonular traction tufts).

Intermediate zone (medium orange) contains vitreal tracts, membranelles that form funnels packed into one another and that diverge from region of papilla anteriorly. Central channel (dark orange) is space delimited by hyaloid tract. It is closed off anteriorly by a retrolental section of anterior vitreous membrane. It contains no typical tracts but only irregularly arranged vitreous fibers, part of which are residua of Cloquet’s canal.

Outermost vitreous tract, the preretinal tract ( 1), separates intermediary substance from vitreous cortex. Innermost tract, the hyaloid tract ( 3), inserts at the edge of the lens. Between these tracts extends the median tract ( 2) to median ligament of pars plana and the coronary tract to coronary ligament.

(From Sebag J: The vitreous. In Hart WM Jr, editor: Adler’s physiology of the eye, ed 9, St Louis, 1992, Mosby.) Cloquet’s CanalCloquet’s canal, also called the hyaloid channel or the retrolental tract, is located in the center of the vitreous body. 2 It has an S shape, rotated 90 degrees with the center dip downward, and is the former site of the hyaloid artery system, which was formed during embryologic development (see Chapter 7). Cloquet’s canal arises at the retrolental space. Its anterior face is approximately 4 to 5 mm in diameter. 2 It terminates at the area of Martegiani, a funnel-shaped space at the optic nerve head that extends forward into the vitreous to become continuous with the canal. 2,60 Composition of VitreousThe highly transparent vitreous is a dilute solution of salts, soluble proteins, and hyaluronic acid contained within a meshwork of the insoluble protein, collagen.

Vitreous is 98.5% to 99.7% water and has been described as having connective tissue status and being an extracellular matrix. 71,74 Because of its high water content, study of the vitreous is difficult. Attempts at tissue fixation often have dehydrating effects that introduce artifacts. Recent investigations suggest that the epithelium of the pars plana has a significant role in the production and secretion of several connective tissue macromolecules of the vitreous body.

74 CollagenThe collagen content of the vitreous is highest in the vitreous base, next highest in the posterior cortex, next in the anterior cortex, and lowest in the center. 60 A fine meshwork of uniform collagen fibrils, each 8 to 16 nm in diameter, is evident on electron microscopy and fills the vitreous body. 69,75-77 The individual fibrils cannot be seen with the slit lamp, but the pattern of variations in their density and regularity can be seen. The density of this collagen fibril network differs throughout the vitreous.

44 Hyaluronic Acid (hyaluronan)The second major vitreal component, hyaluronic acid (HA), a glycosaminoglycan, is a long unbranched molecule coiled into a twisted network. 72 This hydrophilic macromolecule is located in specific sites within the collagen fibril network and is believed to maintain the wide spacing between fibrils.

60 The concentration of HA is highest in the posterior cortex and decreases centrally and anteriorly. 68,78 The gel structure is a result of the interaction of collagen and HA. HA stabilizes the network formed by the collagen strands. HyalocytesVitreous cells, or hyalocytes, are located in a single, widely spaced layer in the cortex near the vitreal surface and parallel to it. 60,72 Various functions have been attributed to these cells. Some investigators have determined that these cells synthesize HA. 79-81 Others have found evidence that hyalocytes synthesize glycoproteins for the collagen fibrils.

60,82 Still others indicate that hyalocytes have phagocytic properties. 72,81,83 Apparently, hyalocytes can have different appearances depending on their activity at a given time.

60 Cells located in the vitreous base are fibroblast-like when anterior to the ora serrata and macrophage-like when posterior to it. 64Fibroblasts present in the vitreous are located in the vitreous base near the ciliary body and near the optic disc. Although composing less than 10% of the cell population, fibroblasts may have been mistaken for hyalocytes in the past.

It is believed that fibroblasts synthesize the collagen fibrils that run anteroposteriorly and are active in pathologic conditions. 60Other cells that have been identified as macrophages likely originate in the nearby retinal blood vessels.

2,71 Vitreal FunctionThe vitreous body provides physical support holding the retina in place next to the choroid, the blood supply for the outer retina. (Neural retina and choroid are only connected to each other at the disc and the ora serrata.) The vitreous is a storage area for metabolites for the retina and lens and provides an avenue for the movement of these substances within the eye. 41 The vitreous, because of its viscoelastic properties, acts as a “shock absorber,” protecting the fragile retinal tissue during rapid eye movements and strenuous physical activity. 2,71 The vitreous transmits and refracts light, aiding in focusing the rays on the retina. Minimal light scattering occurs in the vitreous because of its extremely low concentration of particles and the interfibrillar spacing ensured by the HA-collagen complex. Age-Related Vitreal Changes.

In the infant the vitreous is a very homogeneous, gel-like body. With maturation, changes occur in which the gel volume decreases and the liquid volume increases; this is called vitreous liquefaction or vitreous synersis. 60 By age 40 years, the vitreous is 80% gel and 20% liquid, and by 70 or 80 years it is 50% liquid, 70 with most of the liquefaction occurring in the central vitreous. 71 Both HA and collagen may be detrimentally affected by free radicals that cause conformational changes in the HA molecule and breakdown in collagen cross-links. Subsequent displacement of collagen from the HA-collagen network influences the change from gel to liquid. 46,84,85 As the dissolution of the HA-collagen complex occurs, the macromolecule moves out of the collagen network, causing the fibrils to coalesce into fibers and then into bands. 85,86 The redistribution of collagen leaves spaces adjacent to these bundles, allowing pooling of liquid vitreous; these pockets are called lacunae.

Clinical Comment: Posterior Vitreal DetachmentAs the HA is displaced from the collagen network and as the fibrils coalesce into bundles, the bundles can contract and apply traction to the vitreous and thus to the posterior retina. One of the most common abnormalities that occurs at the posterior retinal-vitreous interface is a posterior vitreal detachment caused by this traction. The vitreous usually detaches from the retinal internal limiting membrane at the peripapillary ring, forming a retrocortical space. If glial tissue is torn away with the vitreous, a circular condensation, Weiss’ ring (senile annular ring), may be visible within the vitreous. 90 If liquid vitreous seeps into the retrocortical space through the prepapillary and premacular areas, a syneresis, or collapse, of the vitreous can follow because of the volume displacement. Isabella Phan, in, 2012 HistologyDue to the high water content, the vitreous chamber appears empty. The volume of vitreous in mice is proportionately smaller than it is in humans.

The vitreous exterior surface is termed the anterior hyaloid face and is behind the lens, whereas the posterior hyaloid face lies just anterior to the retina. The vitreous is firmly attached at the vitreous base located at the ora serrata. Additional firm attachments exist at the optic nerve head, overlying retinal vessels, and near the fovea, which is the region corresponding to highest visual acuity in humans. Goldberg, in, 2013 Stage IVVitreous hemorrhage represents Goldberg stage IV. Sea fans grow or are pulled into the vitreous chamber, and vitreous traction on the delicate neovascular fronds may cause bleeding into the vitreous.

Vitreous hemorrhage may be localized over the sea fan, and an individual may remain asymptomatic. However, dramatic, sudden vision loss may occur as the hemorrhage disseminates into the vitreous gel. Vitreous hemorrhage occurs more commonly in the Hb SC than the Hb SS genotype (23% versus 3%). 70,88,92 The risk of recurrent vitreous hemorrhage also increases if an eye has more than 60° of circumferential retinal neovascularization, or if a patient initially presents with vitreous hemorrhage. 107 Chronic vitreous hemorrhage may give rise to fibroglial membranes and vitreous strands, which may produce traction and resultant retinal detachment. Lee Ann Remington OD, MS, FAAO, in, 2012 Ciliary EpitheliumTwo layers of epithelium, positioned apex to apex, cover the ciliary body and line the posterior chamber and part of the vitreous chamber. The two epithelial layers are positioned apex to apex because of invagination of the neural ectoderm in forming the optic cup (see Chapter 7).

Intercellular junctions, desmosomes, and tight junctions, connect the two layers. 1 Gap junctions between the apical surfaces provide a means of cellular communication between the layers and are important in the formation of aqueous. 14-17 Both epithelial layers contain cellular components characteristic of cells actively involved in secretion.

The outer layer (i.e., the one next to the stroma) is pigmented and cuboidal, and the cells are joined by desmosomes and gap junctions. 1,14,15,19 Anteriorly, the pigmented ciliary epithelium is continuous with the anterior iris epithelium ( Figure 3-15). Posteriorly, it is continuous with the retinal pigment epithelium (RPE) ( Figure 3-16). A basement membrane attaches the pigment epithelium to the stroma. This basement membrane is continuous anteriorly with the basement membrane of the anterior iris epithelium and posteriorly with the inner basement membrane portion of Bruch’s membrane of the choroid. A, Light micrograph of the ciliary body of an elderly person showing transition of posterior pigmented iris epithelium ( a) into nonpigmented ciliary epithelium ( b). Note basement membranelike strip ( c) interposed between dense collagenous connective tissue layers of this ciliary process ( d) and pigmented epithelium ( e).

(×500.) B, Light micrograph of the ciliary body of a young person showing transition of nonpigmented ciliary body epithelium ( b) into pigmented posterior iris epithelium. Epithelium reveals increasing numbers of melanin granules until some of the cells become filled with pigment ( a). Large vein ( c) and a capillary ( d) lie in stroma close to pigmented epithelium. Compare stroma of young eye with that in A.

Some melanocytes ( e) and fibroblasts ( f) are seen. (×640.) (From Hogan MJ, Alvarado JA, Weddell JE: Histology of the human eye, Philadelphia, 1971, Saunders.). A, Light micrograph of ciliary epithelial layers in pars plana.

B, Light micrograph of ora serrata region. Ciliary body at left, retina and choroid at right. Transition from pigmented ciliary epithelium to retinal pigment epithelium and transition from nonpigmented ciliary epithelium to neural retina. (Bright pink artifact is a displaced fragment of the lens.)The inner epithelial layer (i.e., the layer lining the posterior chamber) is nonpigmented and is composed of columnar cells in the pars plana and cuboidal cells in the pars plicata. 1 The lateral walls of the cells contain extensive interdigitations and are joined, near their apices, by desmosomes, gap junctions, and zonula occludens, which form one site of the blood-aqueous barrier. 3,12-16,19-22The nonpigmented ciliary epithelium is continuous anteriorly with the posterior iris epithelium (see Figure 3-15). It continues posteriorly at the ora serrata, where it undergoes significant transformation, becoming neural retina (see Figure 3-16).

The metabolically active nonpigmented epithelial cells are involved in active secretion of aqueous humor components and serve as a diffusion barrier between blood and aqueous. 22 The nonpigmented cells have a greater number of mitochondria than the pigmented cells and thus a higher degree of metabolic activity, with a significant role in the active secretion of aqueous humor components.The basal and basolateral aspects of the nonpigmented cell have numerous invaginations, providing an extensive surface area adjacent to the posterior chamber. 23 The basement membrane covering the nonpigmented epithelium, the internal limiting membrane of the ciliary body, lines the posterior chamber, extends into the invaginations, and is continuous with the internal limiting membrane of the retina.

1,3 The internal limiting membrane in the pars plana region is the attachment site for the zonular fibers and the fibers of the vitreous base. Jonathan J Henry, in, 2003 1 Retina and Iris Pigmented EpitheliaSato (1951) observed that pieces of RPE or pars ciliaris retinae from adult newts ( C.

Pyrrhogaster ) form lenses when implanted into the vitreous chamber ( Fig. Sato (1953) also reported lens formation from fragments of RPE in the anuran, Rana temporaria.

More recently, Hoperskaya and Zviadadze (1981) claimed that RPE enveloped in lens epithelia could give rise to lenses when subsequently implanted into the vitreous chamber in Rana temporaria, and Fedtsova (1991) reported the formation of lenses in explant cultures of embryonic chick RPE.Due to the greater ease with which these cells could be isolated and cultured, the process of transdifferentiation was first demonstrated by Eguchi and Okada (1973) in clonally derived cultures of chick embryonic RPE cells (see also Yasuda, 1979; Yasuda et al., 1981; Eguchi, 1986a,b; Matsuo et al., 1998). These observations were later extended to cultures derived from human embryonic and adult RPE ( Yasuda et al., 1978; Eguchi, 1988; Tsonis et al., 2001). Several factors and conditions are required to promote dedifferentiation and transdifferentiation of pigmented epithelial cells (e.g., Ito and Eguchi, 1986a,b).

More recently, these culture systems have revealed an important role of FGFs in the process of transdifferentiation ( Hyuga et al., 1993; Hayashi et al., 2002, see further discussion below). This area of research has been extensively reviewed ( Okada, 1983, 1991; Eguchi, 1979, 1980, 1986a, 1988, 1998; Yamada, 1982; Tsonis, 2000a–c).The process of transdifferentiation was also demonstrated in cultures derived from dissociated iris epithelial cells of C. Pyrrhogaster ( Eguchi, 1988; Okada, 1991).

Although reaggregated, early primary cultures of ventral IPE will not transdifferentiate, even when reimplanted into the eye ( Okamoto et al., 1998; Ito et al., 1999), ventral IPE cells can transdifferentiate in prolonged monolayer or clonal cultures ( Yamada and McDevitt, 1974; Eguchi et al., 1974; Yamada, 1977; Abe and Eguchi, 1977). IPE cells derived from human embryonic eyes can also transdifferentiate in culture ( Yasuda et al., 1978). More recently, methods have been developed for the convenient preparation of chick IPE cultures and these appear to be very promising for future studies ( Kosaka et al., 1998).

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The crystalline lens is an avascular, transparent elliptic structure that aids in focusing light rays on the retina. The lens is located within the posterior chamber, anterior to the vitreous chamber and posterior to the iris ( Figure 5-1). The lens is suspended from the surrounding ciliary body by zonular fibers.

It is malleable, and ciliary muscle contraction can cause a change in lens shape, increasing the dioptric power of the eye. The mechanism that causes an increase in lens power is accommodation, which allows near objects to be focused on the retina. The peripheral granuloma, also described as the peripheral inflammatory mass form of Toxocara endophthalmitis, is usually seen in a quiet eye with varying levels of decreased vision and strabismus.

19 The vitreous and anterior chamber show mild to moderate reaction. Intense vitritis can occur, however at diagnosis the vitreous is generally clear. Peripheral granuloma presents as a dense, white inflammatory mass in the periphery of the retina.

Localized traction on the retina may result in the production of a typical retinal fold from the periphery to the optic nerve ( Fig. This mass may be quite localized, spherical, and similar to those observed in the posterior pole. Fibrocellular bands may be observed running from a peripheral inflammatory mass to the more posterior retina or the optic nerve ( Fig.

The prognosis in eyes with peripheral granulomatous inflammation is usually relatively good and visual acuity can be preserved. By the time this diagnosis is made, active inflammation is usually not progressive. 19 Ultrasound biomicroscopy study of 15 eyes with peripheral toxocariasis has shown alterations such as vitreous membranes in 86.6%, granuloma in 73.3%, pseudocysts in 53.3%, and thickening of ciliary body in 40% of studied eyes. 46 Intra- and epiretinal traction bands can lead to production of both traction and rhegmatogenous retinal detachments, macular displacement and distortion, and optic nerve dysfunction. In, 2019 Peripheral refractionInstrumentation for in-practice measurement of peripheral refraction is readily available in the form of binocular open-field infra-red autorefractors but further investigation of its structural correlate, posterior vitreous chamber shape, may clarify further the relationship between peripheral and central regions of the retina and its effect on axial elongation in myopia.

For example, in vivo 3-dimensional representation of the human eye using magnetic resonance imaging (MRI) has demonstrated that posterior chamber shape in the emmetropic eye is characterised generally as an oblate ellipse and in the myopic eye as an oblate ellipse of significantly lesser degree such that it approaches that of a sphere with increasing levels of myopia. The more accessible commercially-available non-contact partial coherent interferometry (PCI, e.g. Zeiss IOLMaster, Carl-Zeiss Meditec AG Jena, Germany) can provide in practice on- and off-axis measurements of ocular length. Following direct comparison with MRI data, this has been proposed as a simple and valid method of determining retinal shape ( Verkicharla et al. Nicholas A.V. Beare, Andrew Bastawrous, in, 2014 Eye Complications.Ophthalmic cysticercosis can occur in the orbit, lids, subconjunctival space and intraocularly, most commonly subretinally. It can mimic an orbital tumour or occur as a translucent cyst subretinally, or free floating within the vitreous or anterior chamber.

The typical form of the intraocular cyst may show amoeboid movements and the protoscolex may move ‘in or out’ of the cyst. Symptoms depend on site of the cysticerci, but patients may have flashes of light and visual loss from subretinal lesions. There is little inflammation while the larva is alive, but death of the larva induces a granulomatous inflammatory reaction.