ABO Glaucoma 2 — Questions and Answers
Question 1: A 45-year-old hyperopic woman has persistent appositional angle closure despite a patent laser peripheral iridotomy, and UBM shows anteriorly positioned ciliary processes. What is the most appropriate next laser procedure?
- Repeat laser peripheral iridotomy
- Argon laser peripheral iridoplasty (Correct answer)
- Selective laser trabeculoplasty
- Micropulse cyclophotocoagulation
Correct answer: Argon laser peripheral iridoplasty
Plateau iris configuration persists after iridotomy and responds to argon laser peripheral iridoplasty, which contracts the peripheral iris away from the angle.
Question 2: In acute primary angle closure with an IOP of 62 mmHg, why is pilocarpine often ineffective as initial therapy?
- It increases uveoscleral outflow too slowly
- It is inactivated by the high aqueous protein
- Iris sphincter ischemia prevents miosis at very high IOP (Correct answer)
- It causes ciliary body detachment
Correct answer: Iris sphincter ischemia prevents miosis at very high IOP
At very high IOP the iris sphincter becomes ischemic and unresponsive, so pilocarpine works only after IOP is lowered by other agents.
Question 3: One day after trabeculectomy, a patient has a uniformly flat central and peripheral anterior chamber, IOP of 38 mmHg, a patent iridotomy, and no suprachoroidal fluid on B-scan. What is the best initial treatment?
- Intensive cycloplegia with atropine plus aqueous suppressants (Correct answer)
- Topical pilocarpine 4%
- Immediate repeat laser iridotomy
- Drainage of suprachoroidal hemorrhage
Correct answer: Intensive cycloplegia with atropine plus aqueous suppressants
This is aqueous misdirection (malignant glaucoma), which is initially treated with cycloplegics to tighten the zonules and move the lens-iris diaphragm posteriorly.
Question 4: A patient started on topiramate for migraines 10 days ago presents with bilateral acute myopic shift, shallow anterior chambers, and IOP of 45 mmHg. Which treatment is NOT effective?
- Discontinuing topiramate
- Topical cycloplegics
- Laser peripheral iridotomy (Correct answer)
- Topical aqueous suppressants
Correct answer: Laser peripheral iridotomy
Topiramate causes ciliochoroidal effusion with anterior rotation of the ciliary body, a non-pupillary-block mechanism that iridotomy does not relieve.
Question 5: Which gonioscopic technique best distinguishes appositional angle closure from peripheral anterior synechiae?
- Goldmann three-mirror examination without pressure
- Indentation (dynamic) gonioscopy with a Zeiss four-mirror lens (Correct answer)
- Van Herick slit-lamp estimation
- Koeppe lens examination in the supine position without manipulation
Correct answer: Indentation (dynamic) gonioscopy with a Zeiss four-mirror lens
Indentation with a small-diameter lens pushes aqueous into the angle, opening appositional closure but not synechial closure.
Question 6: On the Van Herick test, which finding suggests an angle at risk of closure?
- Peripheral AC depth equal to corneal thickness
- Peripheral AC depth greater than corneal thickness
- Peripheral AC depth one-half of corneal thickness
- Peripheral AC depth less than one-quarter of corneal thickness (Correct answer)
Correct answer: Peripheral AC depth less than one-quarter of corneal thickness
A peripheral chamber depth under one-quarter of the corneal thickness (grade 1) indicates a potentially occludable angle requiring gonioscopy.
Question 7: Small gray-white anterior subcapsular lens opacities seen after resolution of an acute IOP spike are known as:
- Vossius ring
- Glaukomflecken (Correct answer)
- Christmas tree cataract
- Sunflower cataract
Correct answer: Glaukomflecken
Glaukomflecken are focal lens epithelial necroses that mark a prior episode of acute angle closure.
ABO Glaucoma 2
A 45-year-old hyperopic woman has persistent appositional angle closure despite a patent laser peripheral iridotomy, and UBM shows anteriorly positioned ciliary processes.
What is the most appropriate next laser procedure?