In primary angle-closure glaucoma (PACG), the 'plateau iris configuration' is best characterized by which mechanism leading to angle closure even after patent peripheral iridotomy?
- A Residual pupillary block due to incomplete iridotomy
- B Thick crystalline lens pushing iris-lens diaphragm anteriorly
- C Anteriorly positioned ciliary processes pushing peripheral iris forward against trabecular meshwork ✓
- D Supraciliary effusion causing forward rotation of ciliary body
Correct answer: C. Anteriorly positioned ciliary processes pushing peripheral iris forward against trabecular meshwork
Explanation
Plateau iris configuration occurs due to anteriorly positioned and anteriorly rotated ciliary processes that mechanically support the peripheral iris, keeping it in contact with the trabecular meshwork even after pupillary block has been relieved by peripheral iridotomy. On gonioscopy after iridotomy, the double-hump sign is seen. Treatment requires peripheral iridoplasty (ALPI) to flatten the peripheral iris. Options A, C, and D describe other mechanisms of angle closure but not plateau iris.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.