What is the prevelence of Pigment dispersion syndrome in the caucasian population?
2.5%
What risk factors are there for developing PDS?
- Caucasian Male
- Myopia (80%+)
- Young (30-40yr old)
- No genetic basis
What are the clinical features of PDS?
- Very deep anteror chambers
- Spoke like iris transillumination in approx 70% of patients
- Kruckenberg’s spindle - pigment cells in A/C that congregate on endothelium
- Pigment deposition on the internal structures including anterior iris, lens surface and trab meshwork
What is different about the anatomy in PDS?
Mid peripheral iris concavitity (100%)
Iris-ciliary processes (75%) small attachment from peripheral iris to
Irido-zonular contact (25%)
Detachment of zonula hyaloid membrane - increase risk of RD
What is the 5 year and 15 year risk of developing pigmentary glaucoma if you suffer with PDS?
10% at 5 years
15% at 15 years
An IOP over 21mmHg at diagnosis increases the risk
What is the mechanism by which PDS causes glaucoma?
- Mechanical rubbing of mi-peripheral iris against zonules and anterior capsule during pupil size changes
- Melanin released from iris pigment epithelium
- Pigment cells circulate in aqueous and are deposited in A/C
- Macrophages and pigment reduce outflow via trab meshwork
What percentage of XFS patients have raised IOP
25%
What % of patients with high IOPs and XFS will have secondary glaucoma?
33%
How much more likely is a patient with high IOPs and XFS to convert to GON than someone with simple OHT?
Twice as likely
What is the prevalence of XFS in the over 40s in the UK?
5%
What is the mechanism behind XFS?
It is an ischaemic disorder.
Poor blood flow to the iris results in atrophy
Combination of amyloid material and pigment gets deposited on trab meshwork blocking outflow
What are the clinical signs of XFS?
- Iris atrophy
- White amyloid material deposited on internal structures of AC particularly on the anterior lens surface. Appears as a Bull’s eye ring on dilation
- Associated with zonule weakness (can often see wobbling of iris on slit lamp)
What systemic manifestations of XFS are there?
- Hypertension
- Strokes
- TIA
- MI
What is the overall conversion of XFS to glaucoma?
30-70%
What are the risk factors in the development of XFS?
Northern latitudes (+ Navaho Indians)
Genetic (LOXL1 gene more common with XFS)
Age (doubles every decade from age of 50yrs)
What is XFS?
Production and progressive accumulation of a fibrillar, proteinaceous, extracellular material.
