Intermediate Uveitis

A 32-year-old woman presents with insidious onset of floaters and blurred vision in both eyes over 3 weeks. On examination, she has fine keratic precipitates, anterior chamber cells (2+), and posterior synechiae. Fundoscopy reveals vitritis with snowball opacities and sheathing of retinal vessels. She is otherwise systemically well with no respiratory symptoms or skin lesions. Which of the following is the most likely diagnosis?