Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Pars planitis ?
    ### Response:
    What causes pars planitis? The exact underlying cause of pars planitis is unknown. Scientists suspect that it is an autoimmune condition in which the body's immune system mistakenly attacks healthy tissues (certain parts of the eyes, in this case). This is further supported by the fact that pars planitis is sometimes associated with other autoimmune conditions such as multiple sclerosis and sarcoidosis.
    