Diseases of the Vitreous Body

Overview

The vitreous body Vitreous body The transparent, semigelatinous substance that fills the cavity behind the crystalline lens of the eye and in front of the retina. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe. Eye: Anatomy is the substance present between the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy and the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy. 

• Gel-like material that provides:
  • A clear optical medium 
  • Structural integrity to the eye
• Consists largely of:
  • Water (99%)
  • Network of collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology fibrils
  • Hyaluronic acid Hyaluronic acid A natural high-viscosity mucopolysaccharide with alternating beta (1-3) glucuronide and beta (1-4) glucosaminidase bonds. It is found in the umbilical cord, in vitreous body and in synovial fluid. A high urinary level is found in progeria. Connective Tissue: Histology
  • Peripheral cells (hyalocytes)

Posterior Vitreous Detachment

Definition

Posterior vitreous detachment Vitreous Detachment Detachment of the corpus vitreum (vitreous body) from its normal attachments, especially the retina, due to shrinkage from degenerative or inflammatory conditions, trauma, myopia, or senility. Retinal Detachment is the separation of the vitreous body Vitreous body The transparent, semigelatinous substance that fills the cavity behind the crystalline lens of the eye and in front of the retina. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe. Eye: Anatomy from the internal limiting membrane of the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy.

Epidemiology

• More common in the elderly:
  • Usually starts around 60–70 years of age
  • Most eyes are affected by 80 years of age.
• Men and women equally affected

Etiology

• Age-related vitreous degeneration (most common cause):
  • With age, the vitreous humor Humor Defense Mechanisms changes from a thick vitreous gel to a thin liquid substance. 
  • Vitreous starts to shrink → can lead to its detachment from the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
• Ocular trauma Ocular Trauma Cataracts in Children
• Ocular surgery ( cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2)
• Inflammatory eye disease ( uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea)
• Those with myopia Myopia Refractive Errors are at higher risk owing to elongation Elongation Polymerase Chain Reaction (PCR) of the eyeball.

Clinical presentation

• Most cases are asymptomatic. 
• Myodesopsia ( floaters Floaters Chorioretinitis):
  • Collection of deposits in the vitreous body Vitreous body The transparent, semigelatinous substance that fills the cavity behind the crystalline lens of the eye and in front of the retina. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe. Eye: Anatomy
  • Floaters Floaters Chorioretinitis are most noticeable against a light background and appear in different shapes and sizes.
• Photopsia Photopsia Chorioretinitis:
  • Flashes of light that are sudden and brief
  • Usually unilateral and occur in dark areas
  • Induced by head or eye movement
  • Caused by vitreoretinal traction on retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
• Blurred vision Blurred Vision Retinal Detachment

Diagnosis

• Slit-lamp microscopy: A Weiss ring is a characteristic, mobile membrane within the vitreous cavity that is glossy and crinkled.
• B-scan ultrasonography:
  • Used to study the condition of the vitreous gel 
  • Also helps to determine the extent of posterior vitreous detachment Vitreous Detachment Detachment of the corpus vitreum (vitreous body) from its normal attachments, especially the retina, due to shrinkage from degenerative or inflammatory conditions, trauma, myopia, or senility. Retinal Detachment 

Management

• No treatment is needed in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship without retinal injury.
• Adaption to visual symptoms will develop over time, and floaters Floaters Chorioretinitis can resolve. 
• Vitrectomy Vitrectomy Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma. Retinal Detachment is considered for persistent symptoms.

Complications

• Retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment
• Retinal tear
• Vitreous hemorrhage

Vitreous Hemorrhage

Definition

Vitreous hemorrhage is extravasation of blood into the vitreous humor Humor Defense Mechanisms. 

Etiology

There are many causes of vitreous hemorrhage. Some common causes include:

• Proliferative diabetic retinopathy Diabetic retinopathy Disease of the retina as a complication of diabetes mellitus. It is characterized by the progressive microvascular complications, such as aneurysm, intraretinal edema, and intraocular pathologic neovascularization. Chronic Diabetic Complications
• Posterior vitreous detachment Vitreous Detachment Detachment of the corpus vitreum (vitreous body) from its normal attachments, especially the retina, due to shrinkage from degenerative or inflammatory conditions, trauma, myopia, or senility. Retinal Detachment 
• Ocular trauma Ocular Trauma Cataracts in Children
• Spontaneous retinal tear
• Macular degeneration Macular degeneration Age-related macular degeneration (AMD) is visual impairment due to changes in the macula, the area responsible for high-acuity vision. It is marked by central vision loss with peripheral vision relatively spared. Risk factors include advanced age, smoking, family history, and cardiovascular disease. Macular Degeneration
• Sickle cell retinopathy Retinopathy Degenerative changes to the retina due to hypertension. Alport Syndrome

Clinical presentation

Vitreous hemorrhage is usually painless and unilateral. Signs and symptoms include:

• Visual haze
• Floaters Floaters Chorioretinitis
• Photopsia Photopsia Chorioretinitis
• Photophobia Photophobia Abnormal sensitivity to light. This may occur as a manifestation of eye diseases; migraine; subarachnoid hemorrhage; meningitis; and other disorders. Photophobia may also occur in association with depression and other mental disorders. Migraine Headache
• Perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment of shadows or cobwebs
• Visual acuity Visual Acuity Clarity or sharpness of ocular vision or the ability of the eye to see fine details. Visual acuity depends on the functions of retina, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast. Ophthalmic Exam may be affected, depending on the amount of blood present. 

Diagnosis

• Funduscopic examination can be used to visualize the hemorrhage.
• Slit-lamp microscopy: Blood can be observed between the posterior vitreous base and the internal limiting membrane. 
• Ocular ultrasonography can be used in cases in which the posterior segment is not visible owing to excessive hemorrhage.
• CT/MRI may be needed to assess bony structures and rule out foreign bodies.

Management

• Vitreous hemorrhage might resolve on its own. 
• Treatment is directed toward the underlying cause. 
• Vitrectomy Vitrectomy Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma. Retinal Detachment is done in cases of severe diseases and cases of retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment. 
• Laser photocoagulation is planned for proliferative retinopathies or retinal tear. 

Synchysis Scintillans

Definition

Synchysis scintillans, also known as cholesterolosis Cholesterolosis Cholesterol-laden macrophages or foam cells in the lamina propria of the gallbladder Cellular Accumulations bulbi, is a degenerative condition defined by the accumulation of cholesterol Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Cholesterol Metabolism crystals in liquefied vitreous humor Humor Defense Mechanisms.

Epidemiology

• A very rare condition
• Usually occurs in the 3rd decade of life
• No sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria or race predominance

Risk factors

• Chronic or recurring vitreous hemorrhage (most common)
• Diabetic retinopathy Diabetic retinopathy Disease of the retina as a complication of diabetes mellitus. It is characterized by the progressive microvascular complications, such as aneurysm, intraretinal edema, and intraocular pathologic neovascularization. Chronic Diabetic Complications
• Chronic uveitis Uveitis Uveitis is the inflammation of the uvea, the pigmented middle layer of the eye, which comprises the iris, ciliary body, and choroid. The condition is categorized based on the site of disease; anterior uveitis is the most common. Diseases of the Uvea
• Retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment
• Ocular trauma Ocular Trauma Cataracts in Children

Clinical presentation

• Usually asymptomatic 
• May notice floaters Floaters Chorioretinitis

Diagnosis

• Slit-lamp microscopy:
  • Bilateral floaters Floaters Chorioretinitis can be seen in the posterior chamber Posterior chamber Eye: Anatomy of the eyes
    • Highly refractive
    • Flat
    • Gold/white
  • Crystals float freely (“snow globe” effect)
• Vitreous biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma: can be done as a confirmatory test to identify cholesterol Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Cholesterol Metabolism crystals.

Management

• In general, no treatment is required. 
• Treatment of underlying diseases is necessary. 

Asteroid Hyalosis

Definition

Asteroid hyalosis is a condition in which calcium-lipid ( calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes soap) complexes are attached to the collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology framework of the vitreous body Vitreous body The transparent, semigelatinous substance that fills the cavity behind the crystalline lens of the eye and in front of the retina. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe. Eye: Anatomy. 

Epidemiology

• Seen in approximately 1 in 200 individuals
• Most commonly seen after 50 years of age
• More common in men

Etiology

The disease etiology is unknown.

• Strongly correlated with age
• Not clearly associated with other diseases

Clinical presentation

Asteroid hyalosis is usually asymptomatic.

Diagnosis

The diagnosis is made with slit-lamp microscopy, showing: 

• Unilateral 
• Multiple yellow/white, round opacities
• Floaters Floaters Chorioretinitis are suspended (“stars in the night sky”) → may move, but usually return to their original position

Management

• Treatment is rarely needed.
• Vitrectomy Vitrectomy Removal of the whole or part of the vitreous body in treating endophthalmitis, diabetic retinopathy, retinal detachment, intraocular foreign bodies, and some types of glaucoma. Retinal Detachment may be indicated in cases of severe loss of visual acuity Visual Acuity Clarity or sharpness of ocular vision or the ability of the eye to see fine details. Visual acuity depends on the functions of retina, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast. Ophthalmic Exam.

Persistent Fetal Vasculature

Definition

Persistent fetal vasculature, formerly known as persistent hyperplastic Hyperplastic Colon Polyps primary vitreous, is a condition in which embryonic blood vessels fail to regress.

Etiology

• Failure of the embryonic primary vitreous and hyaloid vascular system to regress
• Majority of cases are not genetic

Clinical presentation

This condition is usually unilateral and may present with:

• Leukocoria Leukocoria Cataracts in Children: white pupillary reflex (also associated with retinoblastoma Retinoblastoma Retinoblastoma is a rare tumor but the most common primary intraocular malignancy of childhood. It is believed that the condition arises from a neuronal progenitor cell. Retinoblastoma can be heritable or non-heritable. Retinoblastoma)
• Decreased visual acuity Visual Acuity Clarity or sharpness of ocular vision or the ability of the eye to see fine details. Visual acuity depends on the functions of retina, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast. Ophthalmic Exam
• Microphthalmia (abnormally small eye due to failure to develop) of the affected eye
• Strabismus Strabismus Strabismus is the misalignment of the eyes while fixating the gaze on an object. Strabismus can be idiopathic, but it may also be caused by cerebral palsy, uncorrected refractive errors, and extraocular muscle or cranial nerve dysfunction. Strabismus

Diagnosis

Persistent fetal vasculature is usually diagnosed right after birth.

• Funduscopy and slit-lamp exam:
  • Rotated and elongated ciliary process
  • Fibrous Fibrous Fibrocystic Change stalk above the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions
• Ultrasonography may show a fibrovascular stalk between the lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy and the optic nerve Optic nerve The 2nd cranial nerve which conveys visual information from the retina to the brain. The nerve carries the axons of the retinal ganglion cells which sort at the optic chiasm and continue via the optic tracts to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the superior colliculi and the suprachiasmatic nuclei. Though known as the second cranial nerve, it is considered part of the central nervous system. The 12 Cranial Nerves: Overview and Functions.
• CT can show:
  • Shallow anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy
  • Increased vitreous chamber Vitreous chamber Eye: Anatomy density
  • Intravitreal tissue enhancement
  • Irregular lens Lens A transparent, biconvex structure of the eye, enclosed in a capsule and situated behind the iris and in front of the vitreous humor (vitreous body). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the ciliary body is crucial for ocular accommodation. Eye: Anatomy

Management

• Treatment is symptomatic
• Vision Vision Ophthalmic Exam correction may be needed. 
• Surgery may be recommended to prevent or treat complications.

Complications

• Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
• Cataract Cataract Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). Neurofibromatosis Type 2
• Intraocular hemorrhage
• Retinal detachment Retinal detachment Retinal detachment is the separation of the neurosensory retina from the retinal pigmented epithelium and choroid. Rhegmatogenous retinal detachment, the most common type, stems from a break in the retina, allowing fluid to accumulate in the subretinal space. Retinal Detachment