A 70-year-old woman presents with acute painful red eye, blurred vision, and a fixed dilated pupil. Examination reveals a shallow anterior chamber, IOP of 48 mmHg, and a mature cataract in the affected eye. The opposite eye has a deep anterior chamber. The most likely mechanism of this acute glaucoma is:

• A Phacolytic glaucoma from lens protein leakage
• B Pseudoexfoliative glaucoma
• C Lens particle glaucoma from retained lens fragments
• D Phacomorphic glaucoma from lens intumescence causing pupillary block ✓

Explanation

Phacomorphic glaucoma occurs when an intumescent (swollen) mature cataract pushes the iris forward, causing pupillary block and secondary angle closure. The shallow anterior chamber in the affected eye versus the normal contralateral eye supports this mechanism. Treatment involves lowering IOP medically followed by urgent cataract extraction. Phacolytic glaucoma involves macrophages clogging the trabecular meshwork with lens protein, causing open-angle glaucoma, not angle closure.

Reference: AAO BCSC Section 11: Lens and Cataract, 2022-2023 ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.