White Dot Syndrome is a classification of rare, idiopathic multifocal inflammatory conditions affecting the retina and underlying choroid at the back of the eye. These syndromes cause inflammation in multiple spots, but their exact cause remains largely unknown. They are characterized by the appearance of small, yellowish-white lesions, or “dots,” within the deeper layers of the eye. White Dot Syndromes typically affect young, healthy adults and often present with a sudden, temporary onset of vision changes.
Defining the Group and Key Characteristics
White Dot Syndromes involve uveitis, or inflammation, in the outer layers of the retina and the vascular choroid. This inflammation creates the characteristic lesions seen during an eye examination. While the precise origin is unclear, many cases are suspected to have an autoimmune component or be triggered by a preceding viral infection. About one-third of patients report experiencing a mild flu-like illness shortly before visual symptoms begin.
The shared symptoms relate directly to the inflammation’s location in the back of the eye. Patients frequently experience a rapid onset of blurred or decreased vision. Common complaints include photopsia (the perception of flashing or shimmering lights), scotomas (blind spots in the field of vision), and an increase in floaters.
The visual disturbance often occurs acutely, sometimes affecting one eye initially. The symptoms correspond to where the lesions are located on the retina. These inflammatory lesions are dynamic, appearing as small, discrete spots that can change over time.
Primary Types of White Dot Syndromes
The White Dot Syndrome classification encompasses several distinct diseases, each with a specific clinical presentation.
Multiple Evanescent White Dot Syndrome (MEWDS) primarily affects young women and is often preceded by a viral illness. The lesions are small and tend to disappear, leading to excellent vision recovery within a few weeks to months, often without treatment.
Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) has an acute onset, often involving both eyes, and causes larger, placoid-shaped lesions. Although initial visual acuity can be poor, the condition is usually self-limiting, and vision spontaneously improves. The lesions eventually leave behind areas of pigment change in the retina, but the visual prognosis is generally favorable.
Punctate Inner Choroidopathy (PIC) affects young, myopic women and involves small lesions deep in the choroid layer. PIC carries an increased risk of developing choroidal neovascularization (CNV)—the growth of abnormal new blood vessels under the retina. This complication requires prompt treatment to prevent severe, permanent central vision loss.
Multifocal Choroiditis and Panuveitis (MCP) is a chronic and potentially recurrent condition. MCP is distinguished by inflammation in the vitreous humor (panuveitis) and multiple chorioretinal lesions that can lead to scarring. Its chronic nature necessitates active management to control inflammation and minimize vision-reducing complications.
Diagnosis and Clinical Evaluation
Diagnosis relies on a detailed eye examination and specialized imaging to visualize the back of the eye. An ophthalmologist performs a fundus examination to view the retina and choroid directly, looking for the characteristic small, yellowish-white dots. This inspection helps determine the size, shape, and location of the lesions.
To detail the inflammation and its effects, doctors use several advanced imaging modalities. Fluorescein Angiography (FA) involves injecting a fluorescent dye that highlights areas of active inflammation and leakage in the retina and choroid. In APMPPE, FA typically shows early hypofluorescence (darkness) followed by late hyperfluorescence (staining) of the lesions.
Optical Coherence Tomography (OCT) provides high-resolution, cross-sectional images of the retina. OCT is useful for identifying fluid buildup and showing the exact depth of inflammatory damage within the outer retina or retinal pigment epithelium. Indocyanine Green Angiography (ICG) uses a different dye suited for visualizing the deeper choroidal blood vessels. ICG typically reveals hypofluorescent spots that are often more numerous than clinically visible lesions.
Treatment Approaches and Prognosis
Treatment strategy depends on the specific subtype and severity. Many syndromes, such as MEWDS and APMPPE, are self-limiting, resolving spontaneously without medical intervention. For these cases, the primary approach is careful observation.
Active treatment is initiated when a syndrome is persistent, chronic, or carries a high risk of long-term vision loss. This involves corticosteroids, administered orally, via injections near or into the eye, or intravenously, to rapidly reduce inflammation and swelling. For chronic or recurrent conditions like MCP, a long-term regimen involving immunosuppressive agents may be necessary to control the disease and minimize the side effects of prolonged steroid use.
The prognosis for most White Dot Syndromes is favorable, with the majority of patients regaining near-normal visual acuity. Some individuals may experience residual symptoms, such as a persistent blind spot or minor visual distortions. Subtypes like PIC and MCP require vigilant monitoring due to the risk of complications like CNV, which can lead to permanent central vision damage if not treated with anti-VEGF injections.