The cause is generally unknown, but a viral illness has been reported prior to multiple evanescent white dot syndrom in one-third of cases. Since the disease occurs primarily in females, hormonal status might be a contributing factor. Acute zonal occult outer retinopathy
Some discrepancy exists as to whether acute zonal occult outer retinopathy is considered a white dot syndrome. However, it may definitely be related to other diseases included in the white dot syndrome group. Acute zonal occult outer retinopathy occurs in young to middle age adults and may eventually progress to retinal cell death. Symptoms include acute visual field loss and photopsias. Suspected causes include autoimmune, viral, and fungal. Multifocal choroiditis and panuveitis
Multifocal choroiditis occurs mainly in myopic females. The fundus presents with yellow or gray lesions (white dots) at the level of the choroid and retinal pigment epithelium. The size of the white dots are between 50 and 500 micrometres and localized in the macula. The disease is characterized by vitritis and anterior chamber inflammation. Decreased vision due to vitreous inflammation may occur. Unlike multiple evanescent white dot syndrome, multifocal choroiditis is a chronic disorder and macular scarring contributes to severe visual loss. Theories regarding the cause include an exogenous pathogen sensitizing an individual to antigens within photoreceptors, retinal pigment epithelium, or choroid. Punctate inner choroiditis
Punctate inner choroiditis is an inflammatory choroiditis which occurs mainly in young females. Symptoms include blurred vision and scotomas. Gray-white or yellow lesions are mainly present in the posterior pole and are between 100 and 300 micrometres in size.
Muller and retinal pigment epithelium cells normally release immunosuppressive factors, but certain combinations of cytokines may stimulate retinal pigment epithelium cells to release factors encouraging inflammation.Generally, mild intraocular inflammation results in a small, discrete, evanescent lesions. Larger dots, having less discrete borders, are the result of high intensity intraocular inflammation. In essence, an immune response with the normal amount and appropriate cytokine release will result in small white dots and a misregulated response eventually will produce scarring of the retinal tissue. Treatment is required in the latter case to combat loss of vision. The white dots usually disappear naturally. Corticosteroids have been shown to speed up this process. The differences in the immune response of each patient may contribute to the differences seen between the white dot syndromes. Distinct diseases
Due to the number of common features among the multiple syndromes, many suggest that the white dot syndromes are not distinct and represent a spectrum of one disease. Gass described the AZOOR complex which consists of multiple evanescent white dot syndrome, nultifocal choroiditis, punctate inner choroiditis, acute idiopathic blind spot enlargement, acute macular neuroretinopathy, acute annular outer retinopathy, and acute zonal occult outer retinopathy. He suggested these diseases represent one disease due to common factors such as a high occurrence in females, unexplained visual field loss, and reduced electroretinographic amplitudes. Reddy et al. conducted a study on the blind spots in multifocal choroiditis, punctate inner choroiditis, multiple evanescent white dot syndrome, and diffuse subretinal fibrosis syndrome. Clinical and electroretinographic evidence suggested the diseases are distinct.