What is White Dot Syndrome?

The retina is the back portion of the eye that is responsible for creating vision and communicating with the brain.

In a healthy individual, the retina will appear red or yellow from the blood vessels and the reflective material which are found in the retina.

The only way to obtain a view of the retina is through special instrumentation that can photograph the back of the eye, or by an eye doctor when examining the eyes using special lenses.

What Causes a White Spot in the Retina?

A white spot in the retina is caused by either a lack of blood to the area or by a collection of inflammation in that area.

If blood is not reaching a portion of the retina, there will be a loss of vision in part of, or all of, the eye. This event is called ischemia and can be caused by a blockage in the vessels or damage from a disease like diabetes.

If there is persistent inflammation in the eye, the inflammation may reach the retina and create spots of white or light yellow on the retina. Unlike ischemia, these spots will typically not affect vision and are more likely to go unnoticed.

Causes of Inflammatory White Dot Syndromes

There are a group of retinal diseases that are termed the white dot syndromes. All of these diseases are similar in how they affect the eyes and appear on the retina.

As the name implies, each of the white dot syndromes will result in white spots of inflammation in the retina.

The most common white dot syndromes are acute posterior multifocal placoid pigment epitheliopathy (APMPPE), multiple evanescent white dot syndrome (MEWDS), birdshot retinopathy, serpiginous choroiditis, punctate inner choroidopathy (PIC), and relentless placoid chorioretinitis (RPC).

Other Differentials for White Dot Syndromes

There are several conditions which are not considered a white dot syndrome but can present with similar findings as these conditions.

These diseases include presumed ocular histoplasmosis syndrome (POHS), toxoplasma chorioretinitis, and sarcoidosis.

Each of these and others cause inflammation and can result in small white patches in the retina in a similar manner to white dot syndromes.

Acute Posterior Placoid Pigment Epitheliopathy

APMPPE is a white dot syndrome that can affect vision in some cases. APMPPE often causes more symptoms early in the course of the disease.

Within two weeks, most cases of APMPPE have resolved spontaneously but more episodes can occur throughout the life.

Multiple Evanescent White Dot Syndrome

MEWDS can severely affect vision and reduces overall vision in many cases while the disease is active.

In most cases of MEWDS, the prognosis is excellent whether there is one or multiple episodes of outbreaks.

Birdshot Retinopathy

Birdshot retinopathy is named for the characteristic scattering of lesions in a pattern resembling the spray of a shotgun shell of birdshot pellets.

This condition can affect night vision and color vision in the later stages of the disease and cause permanent reduction.

Serpiginous Choroiditis

Serpiginous choroiditis presents in a serpentine or snakelike pattern in the retina. Serpiginous retinopathy can reduce overall vision or cause visual field defects.

In severe cases, the reduced vision can be complete in an eye.

Punctate Inner Choroidopathy

PIC is a white dot syndrome that is associated with many courses of the disease waxing and waning as it becomes more or less severe.

PIC can cause blurred vision and distortions in central vision.

Relentless Placoid Choroidopathy

RPC can reduce vision in some cases, but in the majority of cases central vision will be preserved even if the white dots are located in the central portion of the retina.

The episodes of RPC typically take weeks to resolve which give the disease the name “relentless” placoid choroidopathy.

Treatment of White Dot Syndromes

All white dot syndromes are a result of excess inflammation in the retina. Thus, oral steroids or injected steroids can be an option in all of the white dot syndromes.

The biggest complication of the white dot syndromes is a choroidal neovascular membrane which is treated with intraocular injections of anti-VEGF therapy.