**Core Concept**
Cystoid macular edema (CME) is a condition characterized by the accumulation of fluid in the macula, leading to vision impairment. This condition is often associated with inflammation, injury, or disease affecting the eye.

**Why the Correct Answer is Right**
CME commonly develops after cataract surgery, due to the release of inflammatory mediators and the disruption of the blood-ocular barrier. The posterior capsule opacification, which occurs after cataract surgery, can also cause CME. The pathophysiology involves the breakdown of the tight junctions between retinal pigment epithelial cells, leading to fluid accumulation in the macula.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because CME is not typically associated with diabetic retinopathy, although diabetic macular edema is a distinct entity characterized by the accumulation of fluid in the macula due to diabetic retinopathy. While both conditions can cause vision impairment, they have different underlying pathophysiology.

**Option B:** This option is incorrect because glaucoma is a condition characterized by increased intraocular pressure, which can lead to optic nerve damage. While glaucoma can cause vision loss, it is not directly associated with the development of CME.

**Option C:** This option is incorrect because age-related macular degeneration (AMD) is a condition characterized by the degeneration of the macula, leading to vision impairment. While AMD can cause vision loss, it is not directly associated with the development of CME.

**Clinical Pearl / High-Yield Fact**
CME can be prevented or treated with corticosteroids, which reduce inflammation and stabilize the blood-ocular barrier. It is essential to identify and manage CME promptly to prevent vision impairment.

**Correct Answer:** A. Cataract surgery.