White dot syndromes

White dot syndromes are inflammatory diseases characterized by the presence of white dots on the fundus, the interior surface of the eye. The majority of individuals affected with white dot syndromes are younger than fifty years of age. Some symptoms include blurred vision and visual field loss. There are many theories for the etiology of white dot syndromes including infectious, viral, genetics and autoimmune.

Classically recognized white dot syndromes include:

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.

Multiple evanescent white dot syndrome (MEWDS) occurs mostly in females. Symptoms include a sudden loss of central vision, but patients eventually regain normal vision. The white dots are small and located in the posterior pole at the level of the retinal pigment epithelium (RPE). The white dots may disappear after the first few weeks of the disease. The cause is generally unknown, but a viral illness has been reported prior to MEWDS in one-third of cases. Since the disease occurs primarily in females, “hormonal status” might be a contributing factor.

Some discrepancy exists as to whether acute zonal occult outer retinopathy (AZOOR) is actually considered a white dot syndrome. However, AZOOR may definitely be related to other diseases included in the white dot syndrome group. AZOOR occurs in young to middle age adults and may eventually progress to retinal cell death. Symptoms include acute visual field loss and photopsias. Suspected causes for AZOOR include autoimmune, viral, and fungal.

Multifocal Choroiditis (MPC) occurs mainly in myopic females. The fundus presents with yellow or gray lesions (white dots) at the level of the choroid and RPE. The size of the white dots are between 50 and 500 micrometres and localized in the macula. MPC is characterized by vitritis and anterior chamber inflammation. Decreased vision due to vitreous inflammation may occur. Unlike MEWDS, MPC is a chronic disorder and macular scarring contributes to severe visual loss. Theories regarding the cause include an exogenous pathogen sensitizing an individual to antigens within photoreceptors, RPE, or choroid.

Punctate inner choroiditis (PIC) is an inflammatory choroiditis which occurs mainly in young females. Symptoms include blurred vision and scotomas. . Gray-white or yellow lesions are mainly present in the posterior pole and are between 100 and 300 micrometres in size. PIC is one of the so-called White dot syndromes which come under the heading posterior uveitis.The appearance of punctate (punched out) areas is at the level of the inner choroid. These lesions are typically located centrally at the back of the eye (posterior pole).

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