PIGMENTARY GLAUCOMA

Basics & Definition

1. What is Pigment Dispersion Syndrome (PDS)? How does it differ from Pigmentary Glaucoma (PG)?
2. How would you classify PDS according to Richardson's classification?
3. What gene mutation is implicated in PDS and PG, and what does it affect?
4. What percentage of PDS patients develop glaucoma? What is the timeframe?
5. What type of glaucoma is Pigmentary Glaucoma — open or closed angle? Why?

Epidemiology & Risk Factors

1. What is the age of onset for PDS versus PG?
2. What is the gender predilection in PG and why?
3. Why are myopes predisposed to developing PDS?
4. What anatomical features predispose a patient to PDS?
5. Why does exercise trigger pigment release in PDS?
6. What is the significance of "Type A personality" as a risk factor in PG?

Pathophysiology

1. Explain Campbell's mechanical theory of pigment dispersion.
2. What is "reverse pupillary block" and how does it contribute to pigment dispersion?
3. How does pigment cause IOP elevation in PG? What happens to trabecular endothelial cells?
4. What are the four proposed mechanisms of pigment dispersion?
5. Why does iris concavity (posterior bowing) occur in PDS?

Signs & Clinical Features

1. What is a Krukenberg spindle? How is it formed? Is it pathognomonic of PG?
2. Why does the Krukenberg spindle have a vertical, spindle-shaped distribution?
3. What specular microscopy changes occur in PDS? Is endothelial function compromised?
4. What is the "Church window sign" and in which condition is it seen?
5. What is Zentamayer's line (Scheie's line)? Where is it seen and what does it signify?
6. What gonioscopic findings are seen in Pigmentary Glaucoma?
7. What is the Sampaolesi line? Where does pigment accumulate preferentially along the angle?
8. What is the "Pigment Reversal Sign"? What is its clinical significance?
9. Why is PDS sometimes mistaken for Fuchs' endothelial dystrophy? How would you differentiate?
10. What are the UBM findings in PDS?
11. What does AS-OCT show in a patient with PDS?

Evolution & Prognosis

1. What is the "Burnt-out Phase" of pigmentary glaucoma? What happens to IOP?
2. Why can PG in its regression phase mimic low tension glaucoma?
3. What happens to ONH and visual field changes in the regression phase of PG?

Management

1. How does the management of PG resemble POAG management?
2. Why are miotic agents theoretically appealing in PG? What is their mechanism?
3. What is the role of peripheral laser iridotomy in PDS/PG? How does it work?
4. What does UBM show before and after laser iridotomy in PDS?
5. Which classes of IOP-lowering drugs are useful in PG?

PSEUDOEXFOLIATION GLAUCOMA

History & Terminology

1. Who first described pseudoexfoliation syndrome and in what year?
2. What did Lindberg describe in 1917?
3. What is "True Exfoliation" (capsular delamination)? Who described it first and in whom?
4. Who coined the term "True Exfoliation" and what distinguishes it from pseudoexfoliation?
5. What is the role of infrared radiation in true exfoliation (glassblower's cataract)?

Definition & Introduction

1. What is PXF syndrome? Is it purely an ocular disease?
2. Name the systemic organs where PXF material is deposited.
3. What systemic associations/risks are seen in patients with PXF syndrome?
4. What types of glaucoma can PXF lead to — open and closed angle?
5. What is the most common identifiable cause of open angle glaucoma worldwide?

Epidemiology

1. What is the typical age group affected by PXF glaucoma?
2. Is PXF usually unilateral or bilateral? What percentage of unilateral cases become bilateral over 20 years?
3. What percentage of patients with PXF syndrome develop glaucoma?

Clinical & Pathologic Features

1. What are the corneal findings in PXF syndrome? How does this differ from PG?
2. What specular microscopy findings are seen in PXF? What is the significance of finding endothelial changes in the unaffected eye of a unilateral case?
3. Describe the three zones seen on the anterior lens capsule in PXF syndrome.
4. What is the clinical classification of PXF (from preclinical to classic)?
5. On which structures is exfoliative material first detected? How is this diagnosed?
6. What iris changes occur in PXF syndrome? Why does poor mydriasis occur?
7. What is the cause of AC melanin dispersion in PXF?
8. How does the gonioscopic pigment pattern in PXF differ from that in PG?

Genetics & Laboratory

1. What gene mutation is tested in PXF syndrome? What does LOXL1 encode?
2. What is the significance of homocysteine levels in PXF syndrome?
3. Is the same gene (LOXL1) involved in both PG and PXF?

Management — Glaucoma

1. Which prostaglandin analogue is most effective in PXF glaucoma, and what is the order of efficacy?
2. What did the ICEST (International Collaborative Exfoliation Syndrome Treatment) study show?
3. Why is SLT highly effective in PXF glaucoma but less effective in PG?
4. What surgical options exist for PXF glaucoma refractory to medical therapy?

Management — Cataract Surgery

1. What pre-operative considerations are important before cataract surgery in a PXF patient?
2. Why is pupillary dilatation poor in PXF? What intraoperative measures are taken?
3. What is phacodonesis and iridodonesis? Why do they occur in PXF?
4. What happens to AC depth when a PXF patient lies supine during surgery?
5. Why does the capsule behave "pseudoelastic" during CCC in PXF?
6. When is a Capsular Tension Ring (CTR) used during cataract surgery in PXF?
7. Why is hydrodelineation preferred over hydrodissection in PXF cataract surgery?
8. Why is horizontal chop preferred over vertical chop in PXF?
9. What IOL is preferred in PXF patients and why? What is capsular contraction syndrome?
10. Why do IOP spikes occur post-operatively in PXF cataract surgery?
11. What are the four reasons for higher risk of zonular and capsular breaks in PXF cataract surgery?

COMPARISON QUESTIONS

1. Compare and contrast PG and PXF glaucoma across: etiology, age group, laterality, pupil dilatation, gonioscopy pattern, and SLT efficacy.
2. Why is SLT more effective in PXF than in PG despite both having trabecular pigmentation?
3. Both PG and PXF show Sampaolesi line — how would you differentiate them at the slit lamp?
4. Both PG and PXF show specular microscopy changes — how do they differ?

SPOT DIAGNOSIS / APPLIED

1. A 30-year-old myopic male presents with IOP spikes after exercise, a vertical spindle-shaped pigment deposition on the cornea, and spoke-wheel transillumination defects. What is the diagnosis?
2. A patient presents with a whitish disc on the anterior lens capsule with a clear zone and a peripheral granular zone. What is the diagnosis? What are the three zones called?
3. On gonioscopy you see a dense, homogenous, circumferential brown pigment band in the TM. What two conditions does this suggest, and how do you differentiate?
4. A patient with PXF undergoes cataract surgery and the capsule ruptures despite careful surgery. List four predisposing factors.
5. A patient with known PDS presents at age 55 with normal IOP, no disc changes, but the gonioscopy now shows darker pigmentation superiorly compared to inferiorly. What sign is this and what does it mean clinically?