**Question:** Following anatomic factors predispose to glaucoma, EXCEPT:

A. Prolapse of the internal limiting membrane
B. Unilateral cataract
C. Lens subluxation
D. Posterior synechiae

**Core Concept:** Glaucoma is a group of eye diseases that damage the optic nerve and lead to progressive visual impairment or blindness. Anatomic predisposing factors to glaucoma include factors that increase intraocular pressure (IOP), such as shallow anterior chamber depth, small corneal diameter, and increased aqueous humor production. In this question, we are focusing on factors that are not predisposing to glaucoma.

**Why the Correct Answer is Right:**

The correct answer is **D.** Posterior synechiae, as they are a complication of uveitis or other intraocular inflammation, and do not directly affect intraocular pressure or optic nerve health. While uveitis can lead to secondary glaucoma, the primary predisposing factor in this question is the anatomic structure or condition itself, not its association with another condition (like uveitis).

**Why Each Wrong Option is Incorrect:**

A. **Prolapse of the internal limiting membrane (ILM)** is a rare condition that occurs when the inner layer of the retina, the inner limiting membrane, detaches from the underlying structures. It is unrelated to intraocular pressure or optic nerve health and is not a predisposing factor for glaucoma.

B. **Unilateral cataract** is a condition where the lens becomes cloudy, impairing vision. It is not directly related to glaucoma but may indirectly increase IOP if not surgically managed in time. However, the focus here is on primary predisposing factors, and cataracts are not a primary factor for glaucoma.

C. **Lens subluxation** is a condition where the lens dislocates from its normal position. Similar to cataracts, lens subluxation is not a direct predisposing factor for glaucoma, although it may lead to secondary glaucoma if not addressed promptly.

**Clinical Pearl:**

Understanding the distinction between primary and secondary glaucoma is essential in clinical practice. Primary glaucoma is caused by genetic or structural abnormalities, while secondary glaucoma has other causes, such as uveitis, trauma, or cataract surgery. Assessing patients for glaucoma should consider both primary and secondary causes.