Punctate inner choroiditis is one of the so-called White dot syndromes which come under the heading posterior uveitis. The appearance of punctate (punched out) areas is at the level of the inner choroid. These lesions are typically located centrally at the back of the eye, or the posterior pole. Serpiginous choroiditis
Serpiginous choroiditis, also known as geographic or helicoid choroidopathy, is an uncommon chronic progressive inflammatory condition affecting adult men and women equally in the second to seventh decades of life. Nature of white dots
The white dots of the white dot syndromes are lesions that vary in their location in the fundus and in most cases tend to disappear. White dots appear early in the disease stages of punctate inner choroiditis and multiple evanescent white dot syndrome. In this case, the white dot is localized in the posterior pole, small (between 25 and 100 μm), and do not clump together. In contrast, white dots appear later in the disease stages of birdshot choroidopathy, serpiginous choroiditis, and acute posterior multifocal placoid pigment epitheliopathy. The white dots in these diseases may be present throughout the entire fundus, larger (50 to 500 μm), and tend to clump together. Among all these syndromes, there exists some retinal vessel inflammation. The differences in the dots are usually in the size, position, and depth of the lesion within the choroid.The way in which the dots form in some of the white dot syndromes has been reported. The dot appears as a small granuloma which is composed of lymphocytes and macrophages.
This is supported by the difficulty in detecting "retinal autoantibodies" in patients with acute zonal occult outer retinopathy.Two other diseases which also present with white dots on the fundus are retinitis punctata albescens and fundus albipunctatus. These diseases are not white dot syndromes, but have much more defined etiology. Retinitis punctata albescens is caused by mutations in RLBP1, the gene for retinaldehyde binding protein 1. In comparison, fundus albipunctatus is caused by mutations in RDH5 gene for an 11-cis-RDH in retinal pigment epithelium cells. See also
Ophthalmology
Retina
Retinal pigment epithelium

References
External links
PIC Society, a UK based support group and discussion forum for people with a diagnosis of punctate inner choroidopathy
Birdshot Uveitis Society, a UK based support group and discussion forum for people with a diagnosis of birdshot chorioretinopathy