What are the other Names for this Condition? (Also known as/Synonyms)

• TB Uveitis
• Tubercular Uveitis

What is Tuberculous Uveitis? (Definition/Background Information)

• Uveitis is inflammation of the uvea, which is a part of the eye structure. When the inflammation occurs as a result of infection by Mycobacterium tuberculosis, the condition is known as Tuberculous Uveitis
• The uvea is a pigmented layer that consists of the iris, ciliary body, and choroid. The uvea encloses, nourishes, and protects the retina
• Tuberculous Uveitis may occur due to infection of the uvea by Mycobacterium tuberculosis, secondary to infection in another part of the body such as the lungs
• The condition can affect males and females of all ages and ethnicities. However, those with a compromised immune system may be at a higher risk for contracting Tuberculous Uveitis
• Antibiotics and corticosteroids may be used to combat Tuberculous Uveitis. A proper diagnosis and timely treatment leads to positive outcomes for individuals with Tuberculous Uveitis

Who gets Tuberculous Uveitis? (Age and Sex Distribution)

• Tuberculous Uveitis is a rare condition that may affect individuals of all ages
• Both males and females are affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Tuberculous Uveitis? (Predisposing Factors)

Some known risk factors for Tuberculous Uveitis include:

• Being infected with HIV infection and/or AIDS
• Having compromised immunity due to the following factors:
  • Cancer treatments
  • Immunosuppressant drugs used following organ or tissue transplantation
• Trauma to the eyes, which can allow pathogenic bacteria such as Mycobacterium tuberculosis to cause infection
• Exposure to Mycobacterium tuberculosis that results in the presence of tuberculin antigens in the body
• Having tuberculosis elsewhere in the body

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Tuberculous Uveitis? (Etiology)

• Tuberculous Uveitis is inflammation of the uvea (or uveal layer) caused by the tuberculosis-causing bacterium Mycobacterium tuberculosis
• Tuberculous Uveitis may occur due to infection of the uvea by Mycobacterium tuberculosis, secondary to infection in another part of the body such as the lungs
• In addition, Tuberculous Uveitis may also develop as an adaptive immune response to the presence of tubercular antigens in blood. As a result, it is possible for an individual to have Tuberculous Uveitis and a positive tuberculin skin test, but not pulmonary tuberculosis

What are the Signs and Symptoms of Tuberculous Uveitis?

The signs and symptoms of Tuberculous Uveitis may vary between individuals and ether one eye or both eyes may be affected. The condition may also be acute or chronic.

• Acute signs and symptoms have a sudden onset, develop rapidly, and last a period of 3 months
• Chronic signs and symptoms develop slowly over a period of time; they usually persist for over 3 months

Tuberculous Uveitis signs and symptoms can vary in type and severity among affected individuals and may include:

• Anterior uveitis: It may result in eye pain, small specks (floaters) that move through one's field of vision, light-sensitivity and blurred vision
• Intermediate uveitis: It may result in pain in the eye, small specks (floaters) that move through one's field of vision, light-sensitivity and blurred vision
• Posterior uveitis: It may cause blind spots, small specks (floaters) that move through one's field of vision, light-sensitivity and blurred vision; there is also an absence of pain
• Panuveitis: It causes eye pain and inflammation, red eyes, small specks (floaters) that move through one's field of vision, light-sensitivity and blurred vision

How is Tuberculous Uveitis Diagnosed?

Tuberculous Uveitis is diagnosed on the basis of the following information:

• Complete physical examination and thorough medical history evaluation
• Assessment of signs and symptoms
• Eye examination by an eye specialist
• Fundoscopic (ophthalmoscopic) examination by an eye specialist, who examines the back part of the eye (or the fundus)
• Visual acuity test using a special and standardized test chart (Snellen chart)
• Slit-lamp examination: Examination of the eye structure using a special instrument called a slit-lamp. In this procedure, the pupils are dilated and the internal eye structure is examined
• Tonometry: Measurement of intraocular pressure or eye fluid pressure, especially to detect conditions such as glaucoma
• Fundus fluorescein angiography (FFA): In this technique, the eye blood vessels are examined using a fluorescein dye
• Fundus autofluorescence (FAF): It is a non-invasive diagnostic technique to examine the fundus of the eye without using a fluorescent dye by a specialized fundus camera
• Indocyanine green (ICG) angiography: It is used to examine the blood vessels of the choroid using a dye, called indocyanine green, particularly to study the choroid
• B-scan ultrasonography: Special ultrasound scan of the eye through a non-invasive diagnostic tool, to assess health of eye structure
• Electroretinogram (ERG): It is a technique to measure electrical activities in the retinal cells
• Optical coherence tomography (OCT) of eye: It is an ocular imaging technique to visualize the cross section of eye structures such as the retina and optic nerve
• Biopsy studies, if necessary
• Other tests to determine any underlying condition causing Tuberculous Uveitis

Usually ocular tuberculosis, such as Tubercular Uveitis, is diagnosed by high degree of suspicion in endemic areas with atypical findings that do not respond to usual treatments. The suspicion may be raised in patients from endemic areas, such as the Indian subcontinent and Africa, or in those who resided in such regions previously.

The healthcare provider may order the following tests to diagnose ocular tuberculosis.

• Chest X-ray
• Mantoux test
• If Mantoux test result is borderline, then QuantiFERON-TB Gold (QFT) test may be ordered

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Tuberculous Uveitis?

The complications of Tuberculous Uveitis may include:

• Glaucoma: A condition that can cause blindness due to higher intraocular pressure
• Cataracts: When the lens of the eye becomes clouded and cause vision loss
• Retinal detachment: An eye condition wherein the retina gets separated from the eye structures that holds the retinal layers together
• Panuveitis can affect the eye structures such as choroid, optic nerve, vitreous fluid, and retina. It can cause blindness
• Vision loss: If left untreated, posterior uveitis can lead to permanent blindness in some cases. However, both anterior and intermediate forms of uveitis do not usually result in blindness
• Kidney damage, high blood sugar, and high blood pressure, due to steroid treatment
• Recurrent uveitis: The condition may recur if the underlying cause is not identified and treated appropriately

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Tuberculous Uveitis Treated?

The treatment for Tuberculous Uveitis may include the following:

• Prescription of a mixture of antibiotics (such as antituberculous agents)
• Corticosteroids
• Eye drops 
• Medication for pain
• Dark glasses to address photosensitivity

How can Tuberculous Uveitis be Prevented?

Tuberculous Uveitis may be preventable through the following measures:

• Avoiding injury to the eyes
• Seeking medical attention for pre-existing medical conditions that may make an individual vulnerable to Tuberculous Uveitis
• Seeking medical attention for an inactive tuberculosis infection
• Vaccinating
• against tuberculosis in areas where it is prevalent; this may help avoid young children from getting Tuberculous Uveitis
• Long-term follow-ups with regular medical screening at periodic intervals (with tests and physical examinations) to check for or help prevent recurrent Tuberculous Uveitis

What is the Prognosis of Tuberculous Uveitis? (Outcomes/Resolutions)

• The prognosis of Tuberculous Uveitis is dependent upon the severity of the signs and symptoms and associated complications, if any that develops
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• With a timely diagnosis and prompt treatment, the condition can be resolved successfully

Additional and Relevant Useful Information for Tuberculous Uveitis:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/health-topics/vision-center/