In most instances, the diagnosis of toxoplasmic retinochoroiditis is made clinically on the basis of the appearance of the characteristic lesion on eye examination.

Seropositivity (positive blood test result) for Toxoplasma is very common and therefore not useful in diagnosis; however, a negative result i.e. absence of antibodies is often used to rule out disease. Others believe that serology is useful to confirm active toxoplasmic retinochoroiditis, not only by showing positivity but by also showing a significant elevation of titers: The mean IgG values were 147.7 ± 25.9 IU/ml for patients with active disease versus 18.3 ± 20.8 IU/ml for normal individuals.

Antibodies against Toxoplasma:

- IgG : appear within the first 2 weeks after infection, typically remain detectable for life, albeit at low levels;and may cross the placenta.

- IgM : rise early during the acute phase of the infection, typically remain detectable for less than 1 year, and do not cross the placenta.

- IgA : Measurement of IgA antibody titers may also be useful in a diagnosis of congenital toxoplasmosis in a fetus or newborn because IgM production is often weak during this period and the presence of IgG antibodies may indicate passive transfer of maternal antibodies in utero. IgA antibodies however usually disappear by 7 months.

In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be helpful for establishing etiology.

Neuroimaging is warranted in AIDS patients presenting with these findings because intracranial toxoplasmic lesions have been reported in up to 29% of these patients who have toxoplasmic chorioretinitis.

Diagnosis of ARN is outlined by the American Uveitis Society. Though most diagnosis's of ARN are made by clinical features, a physician may take a vitreous sample and have it tested for herpes markers. Common lab tests that are run on the sample include a viral culture, viral PCR, direct/indirect immunofluorescence, viral antibody measurement.

The American Uveitis Society has established the following guidelines for ARN diagnosis:

1. Retinal necrosis with one or more focus points borders in the peripheral retina

2. In the absence of antiviral treatment, the condition progresses rapidly

3. Spreading to the surroundings

4. Buildup of blood vessels

5. Inflammation of the vitreous.

"Toxoplasma" infection can be prevented in large part by:

- cooking meat to a safe temperature (i.e., one sufficient to kill "Toxoplasma")

- peeling or thoroughly washing fruits and vegetables before eating

- cleaning cooking surfaces and utensils after they have contacted raw meat, poultry, seafood, or unwashed fruits or vegetables

- pregnant women avoiding changing cat litter or, if no one else is available to change the cat litter, using gloves, then washing hands thoroughly

- not feeding raw or undercooked meat to cats to prevent acquisition of "Toxoplasma"

Prolonged and intense rainfall periods are significantly associated with the reactivation of toxoplasmic retinochoroiditis. Changes promoted by this climatic condition concern both the parasite survival in the soil as well as a putative effect on the host immune response due to other comorbidities.

Diagnosis of PIC can be difficult because the appearance may be similar to other conditions and types of posterior uveitis, especially other forms of the so called white dot syndromes. The diagnosis is made by eliminating all the other possibilities by careful examination by an experienced ophthalmologist, aided with visual field testing and Fluorescein angiography (an intra-venous dye used to show the blood vessels at the back of the eye).

It is important that the correct diagnosis is made because treatment may be quite different for apparently similar conditions.

In a study done published by the British Journal of Ophthalmology, the cases of ARN/BARN reported in 2001-2002 in the UK, Varicella Zoster Virus was the most common culprit for the disease and presented mostly in men than in women.

Researchers have also looked at two cases of ARN in patients who have been diagnosed with an immunodeficiency virus. The disease presented itself more so in the outer retina until it progressed far enough to then affect the inner retina. The patients were not so responsive to the antiviral agents given to them through an IV, acyclovir specifically. The cases progressed to retinal detachment. The patients tested positive for the herpes virus. Researchers are now wondering if this type of ARN is specific to those who have the immunodeficiency virus.

Chorioretinitis is usually treated with a combination of corticosteroids and antibiotics. However, if there is an underlying cause such as HIV, specific therapy can be started as well.

A 2012 Cochrane Review found weak evidence suggesting that ivermectin could result in reduced chorioretinal lesions in patients with onchocercal eye disease. More research is needed to support this finding.

What happens with PIC depends a lot on the presence or absence of an important complication, Choroidal neovascularization (known as CNV).

Often, the inflammation in PIC is self limiting, not always requiring treatment.

However treatment is advised if there are many active or central lesions, or if there are signs of CNV.

In this condition the posterior uveitis shows a geographic pattern. The inflammation begins in the juxtapapillary choroid and intermittently spreads centrifugally. The overlying retinal pigment epithelium and the outer retina are involved in the inflammatory process.

A closely related condition is multifocal serpiginoid choroiditis. This is caused by tuberculosis.

The distinction between these two conditions is important as the latter responds to anti tuberculosis treatment while the former does not.

Serpiginous choroiditis, also known as geographic or helicoid choroidopathy, is an uncommon chronic progressive inflammatory disease affecting adult men and women equally in the second to seventh decades of life.

Diagnosis includes dilated fundus examination to rule out posterior uveitis, which presents with white spots across the retina along with retinitis and vasculitis.

Laboratory testing is usually used to diagnose specific underlying diseases, including rheumatologic tests (e.g. antinuclear antibody, rheumatoid factor, angiotensin converting enzyme inhibitor <-- error) and serology for infectious diseases (Syphilis, Toxoplasmosis, Tuberculosis).

Major histocompatibility antigen testing may be performed to investigate genetic susceptibility to uveitis. The most common antigens include HLA-B27, HLA-A29 (in birdshot chorioretinopathy) and HLA-B51 (in Behçet disease).

Radiology X-ray may be used to show coexisting arthritis and chest X-ray may be helpful in sarcoidosis.

For diagnosis of NPSLE, it must be determined whether neuropsychiatric symptoms are indeed caused by SLE, whether they constitute a separate comorbid condition, or whether they are an adverse effect of disease treatment. In addition, onset of neuropsychiatric symptoms may happen prior to the diagnosis of lupus. Due to the lack of uniform diagnostic standards, statistics about NPSLE vary widely.

Tests which aid in diagnosis include MRI, electrophysiological studies, psychiatric evaluation, and autoantibody tests.

Ophthalmic examination may reveal neovascularization (creation of new vessels in the retina), retinal vessel narrowing, retinal vessel cuffing, retinal hemorrhage, or possible vitritis (inflammation of the vitreous body) or choroiditis (inflammation of the choroid).

Retinal vasculitis is very rare as the only presenting symptom. Often there is sufficient systemic evidence to help the physician decide between any one of the aforementioned possible systemic diseases. For those patients who present with only vasculitis of the retinal vessels, great investigative effort (Chest X-ray, blood test, urinary analysis, vascular biopsy, ophthalmology assessment, etc.) should be undertaken to ensure that a systemic disease is not the hidden culprit.

Chorioretinitis is often caused by toxoplasmosis and cytomegalovirus infections (mostly seen in immunodeficient subjects such as people with HIV or on immunosuppressant drugs). Congenital toxoplasmosis via transplacental transmission can also lead to sequelae such as chorioretinitis along with hydrocephalus and cerebral calcifications. Other possible causes of chorioretinitis are syphilis, sarcoidosis, tuberculosis, Behcet's disease, onchocerciasis, or West Nile virus. Chorioretinitis may also occur in presumed ocular histoplasmosis syndrome (POHS); despite its name, the relationship of POHS to "Histoplasma" is controversial.

Blurry vision, mild pain in the eyeballs, as well as small yellow, grey, and white spots may begin to appear on the retina.

Specific characteristics regarding the white dots and predicted etiology are presented of selected diseases.

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) primarily occurs in adults (with a mean age of 27). Symptoms include blurred vision in both eyes, but the onset may occur at a different time in each eye. There are yellow-white placoid lesions in the posterior pole at the level of the RPE. Some suggest a genetic predisposition to the disease, while others postulate an abnormal immune response to a virus.

Management of neuropsychiatric lupus is similar to the management of neuropsychiatric disease in patients without lupus. Treatment depends on the underlying causes of a patient’s disease, and may include immunosuppressants, anticoagulants, and symptomatic therapy.

Late congenital syphilitic oculopathy is a disease of the eye, a manifestation of late congenital syphilis. It can appear as:

- Interstitial keratitis – this commonly appears between ages 6 and 12. Symptoms include lacrimation and photophobia. Pathological vascularization of the cornea cause it to turn pink or salmon colored. 90% of cases affect both eyes.

- Episcleritis or scleritis – nodules appear in or overlying the sclera (white of eye)

- Iritis or iris papules – vascular infiltration of the iris causes rosy color change and yellow/red nodules.

- Chorioretinitis, papillitis, retinal vasculitis – retinal changes can resemble retinitis pigmentosa.

- Exudative retinal detachment

Congenital syphilis is categorized by the age of the child. Early congenital syphilis occurs in children under 2 years old, and late congenital syphilis in children at or greater than 2 years old. Manifestations of late congenital syphilis are similar to those of secondary syphilis and tertiary syphilis in adults.

The prognosis is generally good for those who receive prompt diagnosis and treatment, but serious complication including cataracts, glaucoma, band keratopathy, macular edema and permanent vision loss may result if left untreated. The type of uveitis, as well as its severity, duration, and responsiveness to treatment or any associated illnesses, all factor into the outlook.

The retinal lesion can mimic retinoblastoma in appearance, and mistaken diagnosis of the latter condition can lead to unnecessary "enucleation".

Focal proliferative nephritis is a type of glomerulonephritis seen in 20% to 35% of cases of lupus nephritis, classified as type III. As the name suggests, lesions are seen in less than half of the glomeruli. Typically, one or two foci within an otherwise normal glomerulus show swelling and proliferation of endothelial and mesangial cells, infiltration by neutrophils, and/or fibrinoid deposits with capillary thrombi. Focal glomerulonephritis is usually associated with only mild microscopic hematuria and proteinuria; a transition to a more diffuse form of renal involvement is associated with more severe disease.

Involutional lipoatrophy is a cutaneous condition, and is an idiopathic lipoatrophy characterized clinically by non-inflammatory focal loss of fat.

Idiopathic localized involutional lipoatrophy (ILIL) is a rare and nosologically imprecise condition characterized by a focal loss of subcutaneous tissue on one or several sites, occurring without any significant triggering factor or auto-immune background, and regressing spontaneously within a few months.

Multifocal choroiditis and panuveitis (MCP) is an idiopathic inflammatory disorder of unknown etiology affecting the choroid, retina, and vitreous of the eye that presents asymmetrically, most often in young myopic women with photopsias, enlargement of the physiologic blind spot and decreased vision.

The first description of the disease was written in 1973.

In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults with no history of pica. These patients seldom have eosinophilia or visceral manifestations.