In plateau iris syndrome, an acute angle closure attack can occur despite a patent peripheral iridotomy (PI) because:
- A The iridotomy hole becomes blocked by fibrin after several years
- B Aqueous production increases after iridotomy due to release of prostaglandins
- C Anterior rotation and apposition of peripheral iris to trabecular meshwork persists due to anteriorly positioned ciliary body, not pupillary block ✓
- D The lens continues to enlarge and push the iris forward after iridotomy
Correct answer: C. Anterior rotation and apposition of peripheral iris to trabecular meshwork persists due to anteriorly positioned ciliary body, not pupillary block
Explanation
Plateau iris configuration is characterized by anteriorly positioned ciliary processes that mechanically push the peripheral iris forward against the trabecular meshwork, independent of pupillary block. A PI relieves pupillary block but does not address this peripheral iris apposition. Thus, patients can still develop angle closure after a functioning PI — the residual component is the plateau iris mechanism. Argon laser peripheral iridoplasty (ALPI) is used to additionally treat this component.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
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Written and medically reviewed by the StethoPrep medical team.