Purpose: Examine the use of systemic phosphodiesterase inhibition (sildenafil) to clear central serous chorioretinopathy (CSCR). Observations: In a long-standing CSCR patient. sildenafil produced a rapid resolution. When discontinued (dechallenge) the CSCR returned. https://www.halohealthcarers.shop/product-category/cold-thearpy-pack/