White dot syndromes (WDS) are a collection of rare, inflammatory conditions that affect the retina and the choroid at the back of the eye. These disorders are characterized by the appearance of small, pale, or yellowish lesions—the “white dots”—that an eye doctor can observe during a specialized examination of the fundus. WDS typically presents in young, otherwise healthy adults, often leading to sudden visual disturbances. The conditions are thought to be part of an immune or inflammatory response, though the exact cause remains unknown for most types.
Classifying the Group of Syndromes
White dot syndrome is a term for a spectrum of distinct clinical entities that share a common inflammatory appearance. These conditions are differentiated based on the size, location, and pattern of the white lesions, as well as the presence of associated inflammation in the vitreous, the gel-like substance in the eye. The classification is important because each type has a different disease course and visual prognosis.
Multiple Evanescent White Dot Syndrome (MEWDS) is a common type, typically presenting as a sudden, temporary loss of vision in one eye, characterized by numerous tiny white dots in the outer retina that often resolve without leaving scars. Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) involves larger, flatter, yellow-white patches primarily at the level of the retinal pigment epithelium (RPE), which often affects both eyes but usually resolves spontaneously. Punctate Inner Choroidopathy (PIC) and Multifocal Choroiditis (MFC) are closely related and involve smaller, punched-out lesions that primarily affect the choroid and can lead to recurrent episodes and the formation of scar tissue. Serpiginous Choroiditis is a less common but more aggressive type, where the inflammation typically starts near the optic nerve and spreads outward in a snake-like, geographic pattern.
Causes and Patient Experience
The specific cause of most white dot syndromes remains unknown, but a strong link exists between the onset of symptoms and a preceding event, suggesting an autoimmune or post-infectious trigger. Roughly half of patients report experiencing a flu-like illness, such as a respiratory infection or fever, a few days or weeks before their vision problems began. This temporal association suggests the body’s immune system may mistakenly target the tissues of the retina and choroid after fighting off an infection.
Patients experience a sudden onset of visual disturbance, which is usually painless and can range from mild blurring to significant vision loss. A common symptom is the development of blind spots, known as scotomas, which can be central or affect the peripheral vision. Many individuals also report photopsia, which are brief flashes or shimmering lights in their field of vision. Some patients also notice dyschromatopsia, an alteration in color vision, making colors appear washed out. The symptoms can vary widely depending on which specific syndrome is present and whether the macula, the center of the retina responsible for sharp, detailed vision, is involved.
Confirming the Diagnosis
The diagnosis of a white dot syndrome relies heavily on a comprehensive eye examination combined with specialized imaging tests that reveal the underlying inflammatory damage.
Fundus Autofluorescence (FAF)
Fundus Autofluorescence (FAF) is a non-invasive imaging technique that uses the natural fluorescence of lipofuscin within the RPE cells to map the health of the outer retina. Active lesions often show abnormal patterns of hyperautofluorescence, indicating stressed or damaged RPE cells, while older, scarred lesions appear hypoautofluorescent due to RPE cell loss.
Fluorescein Angiography (FA)
Fluorescein Angiography (FA) involves injecting a fluorescent dye into a vein, which travels to the eye’s blood vessels, allowing doctors to observe blood flow and leakage within the retina and choroid. In many WDS types, the active lesions initially block the dye, appearing hypofluorescent, but then progressively stain and become hyperfluorescent in the later phases of the angiogram.
Optical Coherence Tomography (OCT)
Optical Coherence Tomography (OCT) provides a high-resolution, cross-sectional view of the retinal layers. OCT is invaluable for visualizing the exact location and extent of the inflammation, often showing disruption of the outer retinal layers, particularly the ellipsoid zone and RPE.
By using this combination of imaging modalities, ophthalmologists can confirm the presence of the characteristic lesions, determine their activity level, and differentiate between the various white dot syndromes.
Treatment and Visual Recovery
For many types of white dot syndromes, such as MEWDS and APMPPE, the condition is self-limiting and resolves on its own, meaning the primary management strategy is careful observation. In these self-resolving cases, no medication is required, and the focus is on monitoring the patient’s vision and ensuring the lesions fade as expected. However, for more aggressive or chronic subtypes, such as Multifocal Choroiditis, or when the macula is severely affected, active medical intervention is necessary to reduce inflammation and prevent permanent scarring.
Treatment usually involves the use of corticosteroids, which may be administered orally, injected around the eye, or given intravenously, with the goal of quickly suppressing the immune response. For conditions that are chronic or frequently recurrent, immunosuppressive therapies may be employed to manage the underlying inflammation. The overall prognosis for visual recovery is favorable, with most patients recovering good visual acuity within a few weeks to several months, especially with self-limiting types. The majority of individuals regain their baseline vision with minimal lasting visual impairment.