Intermediate uveitis
Encyclopedia
Intermediate uveitis
refers to inflammation
localized to the vitreous and peripheral retina
. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed. Intermediate uveitis may either be idiopathic
or associated with the development of a systemic disease
such as multiple sclerosis
(MS) or sarcoidosis
. As such, intermediate uveitis may be the first expression of a systemic condition. The most common causes of intermediate uveitis are idiopathic (69.1%), sarcoidosis (22.2%), multiple sclerosis (MS), and Lyme Disease (0.6%).
Infectious causes of intermediate uveitis include Epstein-Barr virus
(EBV) infection, Lyme disease
, human T-cell lymphotrophic virus type1 (HTLV-1) infection, cat scratch disease
, and hepatitis C
.
Pars planitis is considered a subset of intermediate uveitis and is characterized by the presence of white exudates (snowbanks) over the pars plana
and ora serrata
or by aggregates of inflammatory
cells in the vitreous (snowballs) in the absence of an infectious
etiology
(eg, Lyme disease
) or a systemic disease (eg, sarcoidosis
). Some authorities believe that patients with pars planitis have worse vitritis, more severe macular edema
, and a guarded prognosis
compared to other patients with intermediate uveitis.
In the United States the proportion of patients with intermediate uveitis is estimated to be 4-8% of uveitis cases in referral centers. The National Institutes of Health
(NIH) reports a higher percentage (15%), which may indicate improved awareness or the nature of the uveitis referral clinic. In the pediatric population, intermediate uveitis can account for up to 25% of uveitis cases.
Permanent loss of vision is most commonly seen in patients with chronic cystoid macular edema (CME). Every effort must be made to eradicate CME when present. Other less common causes of visual loss include rhegmatogenous retinal detachment
, glaucoma
, band keratopathy
, cataracts, vitreous hemorrhage
, epiretinal membrane
, and choroidal neovascularization
.
Although intermediate uveitis can develop at any age, it primarily afflicts children and young adults. There is a bimodal distribution
with one peak in the second decade and another peak in the third or fourth decade.
Associations of the disease with such entities as MS
, sarcoidosis
, or inflammatory bowel disease
suggest an autoimmune component in at least a subset of patients. The clustering of familial cases has led to the investigation of human leukocyte antigen
(HLA) associations. The inciting event appears to be peripheral retinal perivasculitis and vascular occlusion
, leading to ocular inflammation, vitritis, and snowbank formation. The etiology
of the antigenic stimulus is not clear and may be either vitreal or perivascular in nature. It is evident that genetics plays some role in the pathophysiology
of intermediate uveitis, but the importance remains unclear.
Synonyms and related keywords: intermediate uveitis, pars planitis, chronic cyclitis, peripheral uveitis, peripheral cyclitis, peripheral vitreitis, multiple sclerosis, MS, sarcoidosis
Uveitis
Uveitis specifically refers to inflammation of the middle layer of the eye, termed the "uvea" but in common usage may refer to any inflammatory process involving the interior of the eye....
refers to inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
localized to the vitreous and peripheral retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed. Intermediate uveitis may either be idiopathic
Idiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
or associated with the development of a systemic disease
Systemic disease
Life-threatening disease redirects here.A systemic disease is one that affects a number of organs and tissues, or affects the body as a whole. Although most medical conditions will eventually involve multiple organs in advanced stage Life-threatening disease redirects here.A systemic disease is one...
such as multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
(MS) or sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
. As such, intermediate uveitis may be the first expression of a systemic condition. The most common causes of intermediate uveitis are idiopathic (69.1%), sarcoidosis (22.2%), multiple sclerosis (MS), and Lyme Disease (0.6%).
Infectious causes of intermediate uveitis include Epstein-Barr virus
Epstein-Barr virus
The Epstein–Barr virus , also called human herpesvirus 4 , is a virus of the herpes family and is one of the most common viruses in humans. It is best known as the cause of infectious mononucleosis...
(EBV) infection, Lyme disease
Lyme disease
Lyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...
, human T-cell lymphotrophic virus type1 (HTLV-1) infection, cat scratch disease
Cat scratch disease
Cat scratch disease is a usually benign infectious disease caused by the intracellular bacterium Bartonella. It is most commonly found in children following a scratch or bite from a cat by about one to two weeks...
, and hepatitis C
Hepatitis C
Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
.
Pars planitis is considered a subset of intermediate uveitis and is characterized by the presence of white exudates (snowbanks) over the pars plana
Pars plana
The pars plana is part of the uvea, choroidea, one of the three layers that comprise the eye. As a part of the ciliary body, it is about 4 mm long and located near the point where the iris and sclera touch....
and ora serrata
Ora serrata
The ora serrata is the serrated junction between the retina and the ciliary body. This junction marks the transition from the simple non-photosensitive area of the retina to the complex, multi-layered photosensitive region. In animals in which the region does not have a serrated appearance, it is...
or by aggregates of inflammatory
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
cells in the vitreous (snowballs) in the absence of an infectious
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
(eg, Lyme disease
Lyme disease
Lyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...
) or a systemic disease (eg, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
). Some authorities believe that patients with pars planitis have worse vitritis, more severe macular edema
Macular edema
Macular edema occurs when fluid and protein deposits collect on or under the macula of the eye and causes it to thicken and swell. The swelling may distort a person's central vision, as the macula is near the center of the retina at the back of the eyeball...
, and a guarded prognosis
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
compared to other patients with intermediate uveitis.
In the United States the proportion of patients with intermediate uveitis is estimated to be 4-8% of uveitis cases in referral centers. The National Institutes of Health
National Institutes of Health
The National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
(NIH) reports a higher percentage (15%), which may indicate improved awareness or the nature of the uveitis referral clinic. In the pediatric population, intermediate uveitis can account for up to 25% of uveitis cases.
Permanent loss of vision is most commonly seen in patients with chronic cystoid macular edema (CME). Every effort must be made to eradicate CME when present. Other less common causes of visual loss include rhegmatogenous retinal detachment
Retinal detachment
Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness. It is a medical emergency.The retina is a...
, glaucoma
Glaucoma
Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye...
, band keratopathy
Band keratopathy
Band keratopathy is a corneal disease derived from the appearance of calcium on the central cornea. This is an example of metastatic calcification, which by definition, occurs in the presence of hypercalcemia...
, cataracts, vitreous hemorrhage
Vitreous Hemorrhage
Vitreous Hemorrhage is the extravasation of blood into the areas in and around the vitreous humor of the eye. The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye...
, epiretinal membrane
Epiretinal membrane
Epiretinal membrane is a disease of the eye in response to changes in the vitreous humor or more rarely, diabetes. It is also called macular pucker. Sometimes, as a result of immune system response to protect the retina, cells converge in the macular area as the vitreous ages and pulls away in...
, and choroidal neovascularization
Choroidal neovascularization
Choroidal neovascularization is the creation of new blood vessels in the choroid layer of the eye. This is a common symptom of the degenerative maculopathy wet AMD .-Causes:...
.
Although intermediate uveitis can develop at any age, it primarily afflicts children and young adults. There is a bimodal distribution
Bimodal distribution
In statistics, a bimodal distribution is a continuous probability distribution with two different modes. These appear as distinct peaks in the probability density function, as shown in Figure 1....
with one peak in the second decade and another peak in the third or fourth decade.
Associations of the disease with such entities as MS
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
, or inflammatory bowel disease
Inflammatory bowel disease
In medicine, inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis.-Classification:...
suggest an autoimmune component in at least a subset of patients. The clustering of familial cases has led to the investigation of human leukocyte antigen
Human leukocyte antigen
The human leukocyte antigen system is the name of the major histocompatibility complex in humans. The super locus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6, and encodes cell-surface antigen-presenting proteins and...
(HLA) associations. The inciting event appears to be peripheral retinal perivasculitis and vascular occlusion
Vascular occlusion
Vascular occlusion is a sudden blockage of a blood vessel, usually with a clot. It differs from thrombosis in that it can be used to describe any form of blockage, not just one formed by a clot. When it occurs in a major vein, it can, in some cases, cause deep vein thrombosis. The condition is...
, leading to ocular inflammation, vitritis, and snowbank formation. The etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
of the antigenic stimulus is not clear and may be either vitreal or perivascular in nature. It is evident that genetics plays some role in the pathophysiology
Pathophysiology
Pathophysiology is the study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome...
of intermediate uveitis, but the importance remains unclear.
Synonyms and related keywords: intermediate uveitis, pars planitis, chronic cyclitis, peripheral uveitis, peripheral cyclitis, peripheral vitreitis, multiple sclerosis, MS, sarcoidosis