Pseudoexfoliation Glaucoma

The lens zonules are fine fibrils suspending the lens from the ciliary body, and the trabecular meshwork is the primary conventional outflow pathway for aqueous humor. Pseudoexfoliation syndrome (PEX) is a systemic elastotic disorder in which abnormal fibrillar material deposits throughout the anterior segment — coating the lens capsule, zonules, iris, ciliary processes, and trabecular meshwork.

When this material accumulates in the trabecular meshwork and obstructs aqueous outflow, causing glaucomatous optic neuropathy, the condition is termed pseudoexfoliation glaucoma (PXG) — the most common identifiable cause of secondary open-angle glaucoma worldwide.³

The precise pathogenesis of PEX remains incompletely understood despite decades of genetic research (notably implicating the LOXL1 gene, though this alone does not fully explain disease penetrance or severity).³ Emerging areas of investigation include epigenetic factors, disordered autophagy, mitochondrial dysfunction, and a compromised blood-aqueous barrier, with oxidative stress as a common downstream theme.³ Fibrillar material progressively deposits in the trabecular meshwork, increasing outflow resistance, while material on the zonules causes progressive zonular weakness — with major implications for cataract surgery planning.

Many patients are asymptomatic in early PEX, identified incidentally on dilated slit-lamp exam. As glaucoma develops, presentation resembles other open-angle glaucomas, though some patients present with markedly elevated or acutely spiking IOP, particularly after pupillary dilation.

Classic findings include the 'bull's-eye' pattern of material on the anterior lens capsule, patchy/asymmetric trabecular meshwork pigmentation, higher and more fluctuating IOP than POAG, poor pupillary dilation, and phacodonesis or lens subluxation from zonular weakness in advanced disease.¹

Differential diagnosis includes pigmentary glaucoma (different material pattern and demographic, though overlap syndrome can occur), primary open-angle glaucoma without exfoliative material, and other causes of lens subluxation (trauma, Marfan syndrome, homocystinuria).

Diagnosis is made by identifying pseudoexfoliative material on the anterior lens capsule and other anterior segment structures, best visualized after pupillary dilation, combined with standard glaucomatous optic nerve/visual field assessment. In a hospital-based cataract surgery cohort, PEX was identified in 10.7% of eyes, with significantly higher mean IOP and glaucoma prevalence than non-PEX eyes.²

PXG classically responds poorly to medical therapy, and surgical intervention is required more often and earlier than in primary open-angle glaucoma.³ Indications for surgery are markedly more common in PXG than POAG.¹

Cataract surgery in PEX patients requires specific precautions given associated zonular weakness and poor dilation: harder nuclear cataracts are common, and though one hospital-based series found no statistically significant difference in intraoperative/postoperative complication rates between PEX and non-PEX eyes, surgeons should still prepare specific tools (pupil expansion devices, capsular tension rings) in anticipation of the known biomechanical risk factors.²

• PXG carries a roughly ten-fold higher glaucoma risk than the general population once PEX is present
• The classic 'bull's-eye' lens capsule pattern is best seen after pupillary dilation — don't skip dilated exam in at-risk patients
• Always anticipate zonular weakness and poor dilation when planning cataract surgery in PEX patients
• Common pitfall: underestimating IOP fluctuation risk in PXG by relying on a single office IOP measurement
• Common pitfall: confusing the patchy, asymmetric trabecular pigmentation of PXG with the dense, homogeneous pattern of pigmentary glaucoma