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

• Inflammation of the Retina
• Retinal Inflammation

What is Retinitis? (Definition/Background Information)

• Retinitis is an eye condition that results in the inflammation of the retina from various causes, mostly infections. It is a potentially vision-threatening inflammatory eye disease that is normally associated with preceding uveitis (uveal inflammation) or endophthalmitis (inflammation of the intraocular fluid regions)
• The retina is a layer of tissue situated at the back of the eye that helps in sensing light. When the blood supply to the retina is blocked, it will not be able to receive enough blood and oxygen leading to a loss of vision
• The signs and symptoms of Retinitis depend on the underlying cause, but may include slow loss of vision, eye flashes and floaters, sensitivity to light, and sight difficulties under dim light. A healthcare provider may use physical exams, eye exams, and various blood tests to diagnose Retinitis
• Upon diagnosis, treatment options involving steroids or immunomodulators may be provided. Additionally, the healthcare provider will address any underlying conditions that may be contributing to the development and progression of Retinitis. An immediate medical attention is sought to achieve better outcomes and prevent complications
• The prognosis for Retinitis depends on the underlying cause (infection) and severity of the signs and symptoms. The prognosis may be assessed on a case-by-case basis; but with early appropriate treatment, the prognosis is generally good

Who gets Retinitis? (Age and Sex Distribution)

• Retinitis can affect individuals of any age; however, individuals in the 20 to 60 year age category are affected the most
• The prevalence rate of the condition is about 1 in 2,500 to 1 in 7,000
• Both males and females are affected and no gender predilection is noted
• Individuals of different racial and ethnic backgrounds may be affected and no particular preference is noted

What are the Risk Factors for Retinitis? (Predisposing Factors)

The risk factors for Retinitis may include a variety of conditions such as:

• Individuals with decreased immunity due to a host of conditions, such as HIV infection and/or AIDS, cancer or cancer therapy, organ transplant, and any other debilitating illness
• Long-term steroidal therapy resulting in immunocompromised status, or the use of other immunosuppressive drugs
• Exposure of the retina to microbes, such as bacteria, parasites, viruses, and fungi, due to a variety of infections such as:
  • Aspergillosis - infection caused by a type of mold (fungus)
  • Borna disease
  • Bovine thromboembolic meningoencephalitis
  • Cat scratch disease
  • Candidiasis - fungal infection that can cause serious abscesses in the retina
  • Cytomegalovirus infection: In individuals with HIV infection and AIDS, it is the most common cause of vision impairment and blindness
  • Diffuse unilateral subacute neuroretinitis (DUSN) - a parasitic infection affecting the retinal epithelium
  • Herpes simplex virus (HSV) and Herpes zoster virus (HZV) infections causing acute retinal necrosis (ARN) and progressive outer retinal necrosis (PORN)
  • Lyme disease
  • Malignant catarrhal fever
  • Rabies
  • Rocky Mountain spotted fever
  • Swine fever
  • Syphilis
  • Toxocariasis causing ocular larval migrans
  • Toxoplasmosis
  • Tuberculosis
• Infected pregnant women have a high risk of transmitting pathogens to their offspring during pregnancy or at the time of childbirth
• Infections that involve the heart valves, urinary tract, and digestive tract affecting the eye
• Participating in activities that have an increased risk for direct eye injury
• Blood vessel inflammation or vasculitis affecting the eye or retina
• Certain allergies

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 Retinitis? (Etiology)

Retinitis is an eye condition that results in inflammation of the retina. An involvement of the retina is usually preceded by damage to certain eye structures, such as the uvea (pigmented layer of the eye consisting of the iris, ciliary body, and choroid), i.e., a condition called uveitis.

All forms of uveitis, namely anterior uveitis, intermediate uveitis, posterior uveitis, and panuveitis, can progress to involve the retina leading to Retinitis. Hence, some researchers often term Retinitis as a subtype of uveitis. Uveitis can develop from bacterial, viral, fungal, and parasitic infections; or, from several non-infectious causes such as immune disorders, certain malignancies, genetic syndromes, side effects of medications, and eye trauma.

In a vast majority, Retinitis is caused by infectious factors, and hence it is termed Infectious Retinitis; while, in some cases, it occurs from non-infectious factors. Sometimes, the cause of development of Retinitis may remain unknown.

Infectious factors - the following pathogens are implicated:

• Bacteria that may cause tuberculosis, syphilis, Rocky Mountain spotted fever, cat scratch disease, or Lyme disease
• Fungi that may cause aspergillosis and candidiasis
• Viruses causing cytomegalovirus (CMV) infection, herpes zoster infection, herpes simplex virus (HSV) infection, rabies, and HIV infection or AIDS
• Parasites causing toxoplasmosis and toxocariasis

What are the Signs and Symptoms of Retinitis?

The signs and symptoms of Retinitis depend on the underlying cause of the condition. It may vary between the individuals and can either occur suddenly or over a period of time. The signs and symptoms may include:

• Progressive loss of vision
• Nyctalopia or night vision loss; unable to see in dim light
• Blurred vision
• Eye floaters: The individuals experience illusions that some small objects such as spots, hairs, or strings are moving in the eye
• Flashes in the eye: Sudden appearance of ‘flashing’ bright lights causing vision distortion (photopsia)
• Light-sensitivity (photophobia)
• Impaired color vision
• Eye pain, in some cases
• The condition may affect only one eye (unilateral) or both the eyes (bilateral). This is mostly dependent on the underlying cause of Retinitis
• Signs and symptoms associated with uveitis may be noted

Associated presentations of the underlying disorder, condition, or infection causing Retinitis may be observed. In some individuals, the condition can be asymptomatic and present no noticeable symptoms, especially during the initial stages.

How is Retinitis Diagnosed?

A healthcare professional may diagnose Retinitis using the following tests and procedures:

• Physical examination and analysis of previous medical history
• Eye examination by an eye specialist (ophthalmologist or retinal expert)
• Blood tests that include the following:
  • To check for the presence of antibodies in blood
  • Blood culture for infections
  • Complete blood count (CBC) with differential
  • Erythrocyte sedimentation rate (ESR)
• Antibody titer in aqueous humor and vitreous humor fluid samples
• 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 structures
• 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 eye structure
• Tests to determine the underlying condition causing Retinitis

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 Retinitis?

The complications of Retinitis 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
• Over time and due to a lack of proper treatment, the condition can affect other surrounding eye structures such as the lens, optic nerve, and vitreous fluid
• Vitreitis or vitreous inflammation, which may result in the development of epiretinal membranes
• Retinal neovascularization: It can result in loss of partial vision
• Retinal vasculitis: Inflammation of the retinal arterioles (small blood vessels)
• Scleritis: Inflammation of the sclera causing severe eye injury and vision loss
• Central vision loss, if the macular region is affected
• Vision loss: Retinitis can lead to permanent damage to the eye structure and cause blindness, if it is left untreated
• Recurrent Retinitis: The condition may recur if the underlying infectious cause is not identified and treated adequately
• Kidney damage, high blood sugar, and high blood pressure, due to steroid treatment

How is Retinitis Treated?

Early diagnosis and treatment of Retinitis is crucial in preventing complications that may result in irreversible damage to the eye. In general, the management would involve arresting progression of the condition and addressing the underlying causative condition and associated symptoms, with the goal of preserving vision.

Depending on the cause of Retinitis, the treatment can be short-term or long-term. With appropriate treatment, the chance of recurrence (from infectious causes) also decreases. The treatment may include the following measures:

• Treating the infection with appropriate antibiotic, antiviral, antifungal, or antiparasitic medication
• Use of eye drops and oral medications (including pain medications)
• Oral corticosteroids to control inflammation; steroids may also be administered intravenously depending on the underlying cause
• Addressing any nutritional deficiencies, which are known to help reduce severity of the symptoms; these include administration of vitamin A, omega-3 fatty acids, and lutein
• Dark glasses may be prescribed for light-sensitivity
• Administration of immunomodulators, which are medications to control dysfunctional immune system
• In case of chronic Retinitis that fails to get better with medication, surgical procedures, such as vitrectomy or laser surgery, to treat the condition may be considered
• Visual rehabilitation
• Current research include advances in the use of stem cells and gene therapy to treat Retinitis
• Long-term follow-up may be necessary to prevent recurrent infections, in some cases

Addressing any other underlying conditions that may be contributing to progression of the disease; these may include malignancies, autoimmune disorders, or other conditions. This is often very important and forms an inherent part of the treatment plan to successfully resolve Retinitis.

How can Retinitis be Prevented?

It may be difficult to prevent Retinitis, but the risk for the condition may be lowered through the following measures:

• Avoiding or minimizing contact with individuals who have infections
• Washing hands frequently with suitable hand sanitizer
• Treating underlying infections and immunologic conditions, as early as possible
• Avoiding or minimizing contact with pets and animals, especially if you are pregnant or immunodeficient
• Educating the individual and family members about the underlying cause and preventing the development of any modifiable risk factors associated with the underlying condition (where possible)
• Wearing protective gear (such as industrial goggles or protective glasses) during activities that have an increased risk for eye trauma
• Maintaining long-term follow-up to watch out for any recurrences

What is the Prognosis of Retinitis? (Outcomes/Resolutions)

• The prognosis of Retinitis generally varies between individuals. It depends on the following set of factors:
  • Severity of signs and symptoms and development of any complication(s)
  • Underlying cause of the condition
  • Overall health status of the individual, whether immunocompetent or immunocompromised
  • Early diagnosis and treatment
• Individuals, who do not have severe signs and symptoms, lack complications, and generally respond well to treatment, have a better prognosis
• In some, the infection (such as toxoplasmosis) is self-limiting and resolves within a few weeks and no treatment may be necessary
• Individuals with complications, or those who do not avail adequate treatment, may have a poorer prognosis. Without adequate management, Retinitis can result in permanent blindness
• In individuals with poor immune function, the visual prognosis may be guarded

Additional and Relevant Useful Information for Retinitis:

Please visit our Eye & Vision Health Center for more physician-approved health information:

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