Hi doctors, can you tell me what is serpiginous choroiditis?

Rare disease. : Serpiginous choroiditis is a rare, usually bilateral, chronically recurring, acute inflammatory entity which affects otherwise healthy middle-aged men or women. Usually causing painless decrease in vision. Both eyes are commonly affected, although the second eye may not develop lesions for weeks to years after the first eye. The exact cause of serpiginous choroiditis is not known.