**Core Concept**
Uveal effusion syndrome (UES) is a rare condition characterized by the accumulation of serous fluid in the choroid, leading to secondary complications such as vision loss. This condition is often associated with systemic diseases and ocular disorders that affect the choroidal vasculature and drainage.

**Why the Correct Answer is Right**
Uveal effusion syndrome can be associated with various conditions, including serous choroidal detachment, choroidal neovascularization, and secondary glaucoma. The pathophysiology of UES involves the disruption of the normal choroidal drainage, leading to fluid accumulation and subsequent ocular complications. The choroidal vasculature plays a crucial role in the development of UES, and conditions that affect this area are more likely to be associated with the syndrome.

**Why Each Wrong Option is Incorrect**
**Option A:** Conditions such as uveitis and retinal detachment are not typically associated with uveal effusion syndrome. Uveitis is an inflammatory condition that affects the uveal tract, while retinal detachment involves the separation of the retina from the underlying choroid.
**Option B:** Systemic diseases such as hypertension and diabetes mellitus are not directly associated with uveal effusion syndrome, although they may contribute to secondary complications.
**Option C:** Cystoid macular edema (CME) is a condition characterized by the accumulation of fluid in the macula, leading to vision loss. While CME is a complication of uveal effusion syndrome, it is not a condition that is typically associated with UES.

**Clinical Pearl / High-Yield Fact**
Uveal effusion syndrome is often associated with conditions that affect the choroidal vasculature, making it essential to consider these conditions when evaluating patients with choroidal effusions.

**Correct Answer: C. Cystoid macular edema is a complication of uveal effusion syndrome, not a condition that is typically associated with the syndrome.