Intermediate uveitis (pars planitis) is characterized by vitritis and 'snowbank' formation. The snowbank is composed of:

• A Calcium deposits from chronic inflammation
• B Aggregated vitreous fibrocytes and hyalocytes
• C Fibrovascular proliferative tissue over the pars plana and peripheral retina ✓
• D Inflammatory exudate from the ciliary body epithelium

Explanation

The snowbank in pars planitis is a fibrovascular proliferative tissue (fibrous tissue with neovascularization) located at the inferior vitreous base, overlying the pars plana and peripheral retina. It appears as a white exudative plaque on indirect ophthalmoscopy in the inferior periphery. It is not purely exudate but rather an organized fibrovascular membrane. Snowballs are free-floating aggregates of inflammatory cells (macrophages, lymphocytes) within the vitreous, distinct from the snowbank. Complications of snowbank include neovascularization leading to vitreous hemorrhage, and tractional retinal detachment. Treatment options include periocular or systemic corticosteroids, pars plana vitrectomy with membrane peeling, and cryotherapy.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.