Q. What are some complications associated with cataract surgery in PXFG patients?
A) Higher risk of complications due to increased inflammation
B) Lower risk of complications than in non-PXFG patients
C) Higher risk of complications due to progressive zonular damage
D) Similar risk of complications as in POAG patients
Answer: C) Higher risk of complications due to progressive zonular damage, phacodonesis, and lens subluxation
Explanation: Due to progressive zonular damage in PXFG, there is an increased risk of complications during cataract surgery, including phacodonesis (lens wobbling) and lens subluxation. Additionally, late in-the-bag intraocular lens (IOL) dislocation several years after uncomplicated cataract surgery is not uncommon.
Complications Associated with Cataract Surgery in Pseudoexfoliative Glaucoma (PXG)
1. Introduction
Cataract surgery in Pseudoexfoliative Glaucoma (PXG) presents unique surgical challenges due to zonular weakness, poor pupil dilation, and intraoperative instability. PEX affects multiple ocular structures, making both intraoperative and postoperative complications more frequent compared to routine cataract surgery.
✔ Key Challenges in PXG Cataract Surgery:
✅ Weak and fragile zonules, increasing risk of intraoperative lens subluxation.
✅ Poor pupillary dilation due to atrophic iris, increasing difficulty of capsulorhexis.
✅ Higher risk of intraocular pressure (IOP) spikes postoperatively.
✅ Increased risk of intraocular lens (IOL) instability and dislocation.
🚨 Key Clinical Insight:
✔ PXG patients undergoing cataract surgery require specialized techniques and close postoperative monitoring to prevent complications.
2. Intraoperative Complications and Their Management
📌 Pseudoexfoliation Syndrome (PEX) affects multiple ocular structures, making intraoperative complications more frequent and severe.
A. Poor Pupillary Dilation (Small, Rigid Pupil)
📌 Mechanism:
- PEX affects the iris dilator muscle, leading to atrophy and loss of function.
- Reduced iris elasticity results in poor response to mydriatic drops.
- Intraoperative miosis occurs due to mechanical stress on the iris.
✔ Risk Factors for Poor Dilation:
- Severe PEX with extensive iris atrophy.
- Chronic IOP elevation leading to ischemic damage of the iris.
- Use of systemic alpha-blockers (e.g., tamsulosin – “Floppy Iris Syndrome”).
✔ Management Strategies:
| Technique | Mechanism | Advantages |
| Intracameral Phenylephrine (0.1–0.3% solution) | Stimulates iris dilator muscle | Quick, effective pupil dilation |
| Viscomydriasis (Healon 5 or DisCoVisc) | Mechanical stretching of the pupil with cohesive OVD | Protects endothelium while dilating |
| Pupil Expansion Devices (Malyugin Ring, Iris Hooks) | Mechanical expansion of rigid pupils | Prevents intraoperative miosis |
| Sphincterotomies (Radial Iris Incisions) | Improves dilation in extreme cases | Last resort |
🚨 Key Clinical Insight:
✔ A Malyugin ring should be considered in PXG cases with significant iris atrophy to maintain stable dilation.
B. Zonular Weakness and Lens Subluxation
📌 Mechanism:
- PEX deposits weaken the zonular fibers, increasing the risk of intraoperative lens instability.
- Progressive zonular dehiscence can lead to phacodonesis (lens wobbling) or lens subluxation.
- Hydrodissection and phacoemulsification forces can worsen zonular dehiscence.
✔ Risk Factors for Zonular Weakness:
- Longstanding PXG with high IOP.
- Severe PEX material accumulation on zonules.
- Previous intraocular surgery (e.g., vitrectomy, trauma).
✔ Management Strategies:
| Technique | Mechanism | Advantages |
| Capsular Tension Ring (CTR) | Redistributes tension across remaining zonules | Prevents intraoperative and postoperative IOL decentration |
| Capsular Tension Segment (CTS) | Anchors the lens capsule in focal zonular dehiscence | Useful in severe zonular loss |
| Slow, Gentle Hydrodissection | Minimizes stress on weak zonules | Reduces risk of lens dislocation |
| Low Phaco Power and Fluidics | Reduces mechanical stress on zonules | Prevents further zonular loss |
| Manual Small-Incision Cataract Surgery (MSICS) | Alternative to phacoemulsification in cases of extreme zonular instability | Minimizes intraoperative complications |
🚨 Key Clinical Insight:
✔ A CTR should be inserted early in the procedure if zonular instability is detected.
✔ Avoid excessive fluid turbulence and rotational forces during phacoemulsification.
C. Capsular Rupture and Vitreous Loss
📌 Mechanism:
- Weakened zonules increase the risk of posterior capsule rupture.
- Zonular dialysis leads to increased stress on the capsule.
- Hydrodissection and phaco maneuvers can extend pre-existing capsule instability.
✔ Management Strategies:
| Technique | Mechanism | Advantages |
| Staining Capsule with Trypan Blue | Enhances visibility of weak capsule | Reduces risk of incomplete capsulorhexis |
| Slow, Controlled Capsulorhexis | Prevents extension of radial tears | Essential for IOL stability |
| Anterior Vitrectomy if Vitreous Loss | Prevents retinal traction and detachment | Reduces postoperative complications |
🚨 Key Clinical Insight:
✔ If a posterior capsular rupture occurs, consider an anterior chamber (AC) IOL or scleral-fixated IOL instead of a capsular-fixated IOL.
3. Postoperative Complications and Their Management
📌 PXG patients are at high risk for post-cataract surgery complications, requiring close monitoring.
A. Intraocular Pressure (IOP) Spikes
📌 Mechanism:
- PXG eyes are predisposed to IOP spikes due to trabecular meshwork dysfunction.
- Postoperative inflammation and retained OVD contribute to transient IOP elevation.
✔ Management Strategies:
| Preventive Strategy | Mechanism |
| Preoperative IOP Optimization | Reduce IOP with acetazolamide if >25 mmHg pre-op |
| Complete Removal of OVD at End of Surgery | Reduces postoperative pressure spikes |
| Topical Beta-Blockers or CAIs Postoperatively | Prevents IOP rise in the first 24 hours |
| Early Postoperative Follow-Up | IOP check at 1 day and 1 week |
🚨 Key Clinical Insight:
✔ PXG patients should have IOP checked within 24 hours of cataract surgery.
B. Late Intraocular Lens (IOL) Decentration or Dislocation
📌 Mechanism:
- Progressive zonular dehiscence post-surgery leads to IOL instability.
- Capsular bag contraction due to PEX material accumulation can shift the IOL.
✔ Management Strategies:
| Preventive Strategy | Mechanism |
| Use of a Capsular Tension Ring (CTR) in Surgery | Prevents capsular contraction and IOL decentration |
| Avoiding Large Posterior Capsulotomies | Prevents weakening of zonular support |
| Scleral or Iris-Sutured IOL in Cases of Severe Zonular Loss | Provides long-term stability |
🚨 Key Clinical Insight:
✔ Late IOL dislocation is more common in PXG than in normal eyes, requiring surgical repositioning or exchange.
4. Summary: Key Complications and Their Management in PXG Cataract Surgery
| Complication | Mechanism | Management Strategies |
| Poor Pupil Dilation | Atrophic iris, weak response to mydriatics | Malyugin ring, intracameral phenylephrine |
| Zonular Weakness | PEX material deposition weakens zonules | Capsular Tension Ring (CTR), gentle phaco |
| Capsular Rupture | Increased lens instability | Staining with trypan blue, slow capsulorhexis |
| IOP Spikes | Poor aqueous outflow post-op | Complete OVD removal, IOP-lowering drops |
| Late IOL Dislocation | Progressive zonular loss | CTR at surgery, scleral fixation if needed |