The White Dot Syndromes

Yoko Matsumoto, MD, PHD; Sebastian P. Haen, MD; Richard F. Spaide, MD

Disclosures

Compr Ophthalmol Update. 2007;8(4):179-200. 

In This Article

Multiple Evanescent White Dot Syndrome

Multiple evanescent white dot syndrome was first described by Jampol et al in 1984. It primarily affects young adults between the ages of 20 and 45 years.[113] There is a strong gender predilection to women, but no racial preference. Multiple evanescent white dot syndrome is highly associated with HLA–B51.[89] Multiple evanescent white dot syndrome was described as being acute, multifocal, and usually unilateral. The spots were thought to be in the outer retina or, possibly, to involve the RPE. Later, ICG angiographic investigation showed that there are many spots within the choroid as well, thus making the disease a retinochoroidopathy.[35,90,114,115,116] Bilateral cases have been described.[117,118] Myopia is commonly associated with MEWDS.[119] Although MEWDS is normally a selflimiting disease, some cases of recurrence have been reported.[120]

Jampol described MEWDS and other diseases, such as acute zonal occult outer retinopathy (AZOOR) and MCP, to be discrete, separable entities with different prognoses and different therapeutic regimens.[88] Meanwhile, Gass subsumed these diseases under the AZOOR complex of disorders.[91] His hypothesis was that viral or other infectious agents entering the receptor cells at the optic nerve head and ora serrata may be responsible for zones of acute receptor cell loss in the AZOOR complex disorders. Some patients with MEWDS have had chorioretinal scars suggestive of MCP.[114]

Multiple evanescent white dot syndrome is characterized by sudden visual alterations in one eye with blurred vision, temporal or paracentral scotomas, photopsia, and dyschromatopsia. An antecedent flulike illness has been reported in approximately one-third of cases.[121,122] Cases of MEWDS following hepatitis A and B vaccinations have been described.[47,123]

A viral etiology of MEWDS has been suggested, possibly associated with an immune-mediated mechanism.[122,123,124] In support of this hypothesis, the serum levels of IgM and IgG in patients have been found to be elevated.[125] Fluorescein angiographic and electrophysiologic studies have suggested involvement of the RPE and photoreceptors.[113,126] The findings in ICG angiography suggest that MEWDS affects the choroid as well.[116,127]

The fundus lesions are multiple, small, whitish, well-defined dots and spots located predominantly in the paramacular area[35] (Figure 9). These spots have a wispy border and an altered sheen arising from the deep retina or the level of the RPE.[128] The spots vary in size from about 200 ì m to one-half disk diameter. If there are numerous spots, they may become confluent. The spots last for a few days to a week. When they initially disappear, they may leave darker spots in their wake.[114] It is common to see additional spots appear with frequent follow-up of the patient over the first few days.

Concurrent with the spots, patients may have cells in the vitreous and optic nerve swelling.[129,119] Atypical findings include circumpapillary patches with or without perimacular involvement and CNV.[130,131] Macular granularity might persist after resolution of the white dot lesions.[35,120]

During fluorescein angiography, the white dots appear as subtle wreaths of smaller hyperfluorescent dots (Figure 9). The optic disk may show leakage in the later phase, persisting even after resolution of the fundus lesions.[128] Indocyanine green angiography reveals multiple small, round, hypofluorescent spots in the posterior and midperipheral fundus (Figure 9). The tiny dark dots seen during ICG angiography correspond with the tiny wreath-like dots seen during fluorescein angiography.[114] There is no evidence of abnormal choroidal perfusion in the early phase. Many lesions in the choroid have darker dots ringing their outer border. The spots in the choroid can become nearly confluent, and early after ophthalmoscopic resolution of the white spots, the ICG findings, particularly the rings of hypofluorescent dots, remain.[132,133] Eventually, the ICG abnormalities resolve.[127,134,135]

Electroretinogram reveals different results during the course of the disease. In the early stages, it shows supernormal responses. In the course of the disease, the amplitudes decrease to normal or subnormal values, representing decreased photoreceptor activity. Detection of early stages of MEWDS is possible using ERG.[34,136,137] Electrooculogram also shows abnormal results. Results of both the ERG and EOG usually return to normal after resolution of the symptoms. Visual field testing reveals enlargement of the blind spot, and temporal and paracentral scotomas.[90]

As MEWDS is self-limiting, treatment is usually not required. Treatment is indicated for concurrent CNV. Past treatment options included photocoagulation or PDT,[130] although use of anti-VEGF drugs would probably be a better option today.[61,62]

The prognosis for MEWDS is generally very good. Initial visual acuity ranged from 20/20 to 20/ 400.[43] Approximately 6 weeks after the first symptoms, almost all patients returned to the pre-onset levels.[35] Concurrent blind spot enlargement may last for weeks to months,[90,129] and some patients may have longterm dyschromatopsia. Some cases of recurrence have been reported.[120]

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