Inflammatory Chorioretinopathies of Unknown Etiology white dot syndromes

a group of idiopathic multifocal inflammatory conditions involving the retina and the choroid

acute posterior multifocal placoid pigment epitheliopathy (APMPPE) birdshot chorioretinopathy multiple evanescent white dot syndrome (MEWDS) multifocal choroiditis with panuveitis (MFC) serpiginous choroiditis

Discrete, multiple, well-circumscribed yellow- white lesions at the level of the retina, outer retina, RPE, choriocapillaris, and choroid

The etiology of the white dot syndromes is unknown

Bilateral involvement ( MEWDS) younger than 50 years of age (birdshot retinochoroidopathy and serpiginous)

Common presenting symptoms: Photopsias Blurred vision Nyctalopia Floaters Visual field loss (blind spot enlargement ) Mild vitritis ( usually)

differential diagnosis : Syphilis Diffuse unilateral subacute neuroretinitis (DUSN) Tuberculosis Toxoplasmosis Pneumocystis choroidopathy Candidiasis Acute retinal necrosis (ARN)

Ocular histoplasmosis syndrome (OHS) Sarcoidosis Sympathetic ophthalmia VKH syndrome Intraocular lymphoma

Morphology Evolution Distinct natural histories Angiographic behavior

a prodromal viral syndrome can be identified

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE)

Healthy young adults Typically surrounding an influenza-like illness (50%) Men and women being affected equally Usually nonrecutrent disease

A sudden onset of bilateral Asymmetric visual loss associated with central and paracentral scotoma

Minimal anterior segment inflammation Mild to moderate vitritis

Funduscopic findings: multiple, large, flat, yellow-white placoid lesions at the level of the RPE, varying in size from 1 to 2 disc areas, located throughout the posterior pole to the equator

CME is uncommon

The lesions resolve over a period of 2 to 6 weeks leaving a permanent geographic-shaped alteration in the RPE

The diagnosis of APMPPE is based on the characteristic clinical presentation and characteristic FA findings during the acute phase of the disease

fluorescein angiography: Early hypofluorescenc Staining in the late phase

Serpiginous choroidopathy

Uncommon Chronic, progressive inflammatory Adult men and women equally Second to sixth decades of age life Minimal vitreous involvement A quiet anterior chamber

Gray-white lesions at the level of the RPE projecting in a pseudopodial or geographic manner from the optic nerve in the posterior fundus

Acute lesions are commonly located adjacent to atrophic scars

The disease course is marked by progressive centrifugal extension, with marked asymmetry between the 2 eyes

Fluorescein angiography : Early hypofluorescence of the active lesions Staining of the active edge of the lesion in the later stage

Systemic immunomodulation has been suggested as first-line therapy because corticosteroids alone are ineffective

Multiple evanescent white dot syndrome (MEWDS)

Unilateral (80%) Central or peripheral scotoma Healthy young (10-47 years) Moderately myopic females (90%) Frequently surrounding a flulike prodrome

multiple, discrete white orangish spots(100-200 μm) at the level of the RPE or deep retina, typically in a perifoveal location

These spots are transitory and are frequently missed; they leave instead a granular macular pigmentary change

Few associated vitreous cells Mild blurring of the optic disc

Punctate hyperfluorescent lesions in a wreathlike configuration surrounding the fovea that stain late

The prognosis is excellent, and vision is completely recovered in 2-10 weeks without treatment

Birdshot retinochoroidopathy

Females (common) The fourth decade of life HLA-A29 (80%-98%)

Anterior segment inflammation may be minimal or lacking Varying degrees of vitritis ( commonly)

Multifocal,hypopigmented, ovoid, cream-colored lesions (50-1500 μm) at the level of the choroid and RPE in the postequatorial fundus

These lesions radiate from the optic nerve and follow the larger choroidal vessels

Retinal vasculitis CME Optic nerve head inflammation

Fluorescein angiography : Mild hyperfluorescence and staining in the late phase Identifying active retinal vasculitis, CME, and optic nerve head leakage

The course is generally marked by multiple exacerbarions and remissions

Treatment: Systemic corticosteroids Corticosteroid-spadng immunomodulatory agents Periocular corticosteroid injections

Conclusion: Because of the significant overlap among them, the various white dot syndromes may just represent a spectrum of the same disease