What are the White Dot Syndromes?
The White Dot Syndromes are a group of idiopathic choroidal inflammatory disease that are characterized by the appearance of white spots in the retina. They include Acute Multifocal Placoid Pigment Epitheliopathy (APMPPE), Serpiginous Choroiditis, Multiple Evanescent White Dot Syndrom (MEWDS), Multifocal Choroiditis and Panuveitis (MCP), Punctate Inner Choroidopathy (PIC), and Diffuse Subretinal Fibrosis (DSF), Birdshot Retinochoroidopathy (BSRC), and Presumed Ocular Histoplasmosis (POHS) round out the white dot syndromes. Each is distinguished by presentation, history, findings on exam and each has a different prognosis and treatment plan.
Acute Multifocal Placoid Pigment Epitheliopathy (APMPPE)
APMPPE typically presents with bilateral acute painless loss of vision in a young adult. A third of patients note a preceding viral syndrome. On examination patients typically have vitreous inflammation with diffuse variable sized yellow white spots. With time the lesions typically fade leaving behind some trace retinal pigment changes. In the vast majority of patients vision typically returns to normal. As a result treatment is typically not warranted. In rare cases where recurrence occurs or if the disease involves the macula steroid or anti-VEGF therapy may be considered. There have been some reported cases of associated cerebral vasculitis in those situations there is a clear benefit to intravenous steroid therapy.
Serpiginous Choroiditis can present with unilateral or bilateral visual loss it usually has associated blind spots and visual distortions and is more common in middle aged men. On examination the lesions typically start at the optic nerve and spread out like a serpent in inflammatory waves that may occur weekly, monthly or every couple of years. New inflammation typically starts at the edge of an old lesion. Complications include destruction of the macula and the development of choroidal neovascular membranes (CNVM). If patients develop CNVM they may benefit from anti-VEGF therapy. Due to the poor prognosis and chronic recurrent nature of the disease Ocular Immunologists and Uveitis experts typically treat Serpiginous Choroiditis quite aggressively. Treatment protocols may include oral steroids, cyclosporine, azathioprine, and or chlorambucil.
Multiple Evanescent White Dot Syndrom (MEWDS)
MEWDS typically presents as acute painless unilateral vision loss in a middle aged female. Approximately 50% of patients have a viral prodrome and they often note associated visual disturbances and visual field defects. On exam patients typically face small round subtle lesions with some foveal granularity. Like APMPPE, MEWDS is typically a self limited disease as a result treatment is rarely warranted. The one exception is when CNVM develop which is an exceedingly rare complication. If that occurs patients benefit from anti-VEGF therapy.
Multifocal Choroiditis and Panuveitis (MCP), Punctate Inner Choroidopathy (PIC) and Diffuse Subretinal Fibrosis (DSF)
MCP, PIC, DSF typically presents as an acute painless loss of vision with associated visual field loss and visual disturbances. It is more common in near sighted females. These particular White Dot syndromes are believed to represent a spectrum of the same diseas and there are many Uveitis experts who do not distinguish between the three.
On exam these patients have multiple to hundreds of mid-peripheral deep retinal lesions with an associated vitreous inflammatory reaction in MCP and DSF. Complications including CNVM development and scarring around the optic disc are quite common. Unfortunately MCP, PIC, and DSF are chronic recurrent diseases as a result up to a third of patients loss significant vision. Due to the poor prognosis Ocular Immunologists and Uveitis experts often recommend steroid therapy and or steroid sparing immunosuppressive therapy in an effort to prevent further damage.
Birdshot Retinochoroidopathy (BSRC)
BSRC typically presents as a slow indolent disease. Patients typically note a slow progressive loss of vision, with associated decrease in night vision and color perception. It is more common in middle aged females. On exam these patients often multiple retinal lesions that resemble “birdshot in the scatter from a shotgum.” Supportive testing includes human leukocyte antigen testing, electrophysiological testing, visual field testing and ICG retinal photography. Despite BSRC being a slow indolent disease with time patients will go blind if not treated appropriately. As a result Ocular Immunologists and Uveitis experts typically recommend steroid sparring immunosuppressive therapy in an effort to prevent permanent vision loss.
Presumed Ocular Histoplasmosis (POHS)
POHS is presumed to occur in patients who are exposed to Histoplasmosis and are genetically susceptible to develop an autoimmune reaction. This assumption has been made do to the higher prevalence of the disease in areas endemic to Histoplasmosis. Patients typically present with visual distortion only when the lesion effects the center of there vision. There is no sex prediliction and the disease typically presents between the age of 20-50. Complications include the development of CNVM which mandate treatment with anti-VEGF therapy. Unfortunately despite our advances in immunosuppressive therapy patients with POHS rarely respond to steroid sparring immunosuppressive therapy.