An 80-year-old woman presents with a painful red eye and vision of counting fingers. She has had a white mature cataract for years and refused surgery. Intraocular pressure is 42 mmHg, the anterior chamber contains free-floating white particles, keratic precipitates are absent, and the fellow eye is quiet with a similar mature cataract. What is the mechanism of her raised intraocular pressure?
- A Anterior displacement of the iris-lens diaphragm with pupillary block
- B Blockade of the trabecular meshwork by macrophages engorged with lens proteins ✓
- C Granulomatous inflammation against retained lens antigen
- D Forward rotation of the ciliary body with ciliochoroidal effusion
Correct answer: B. Blockade of the trabecular meshwork by macrophages engorged with lens proteins
Explanation
Phacolytic glaucoma occurs when liquefied lens proteins leak through an intact capsule of a hypermature cataract; they are engulfed by macrophages which physically obstruct the trabecular meshwork, giving an open-angle, high-pressure eye with floating white material and little true inflammatory reaction. Option A describes phacomorphic or pupillary-block mechanism, and option C describes phacoantigenic uveitis, both clinically distinct entities.
Reference: Parsons' Diseases of the Eye, 23rd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.