pigment dispersion syndrome & pigmentary glaucoma

PIGMENT DISPERSION SYNDROME & PIGMENTARY

GLAUCOMA

MARC P. JAPITANA MDDepartment of Ophthalmology

CLMMRH

OVERVIEW

PIGMENT DISPERSION SYNDROME

– abnormal amounts of pigment are liberated from the posterior surface of the iris

– pigments are deposited all throughout the anterior and posterior chambers of the eye

PIGMENTARY GLAUCOMA

– a secondary glaucoma that develops among patients with PDS

PATHOPHYSIOLOGY

The Mechanical Abrasion Theory

Abiotrophy Theory

MECHANICAL ABRASION THEORY

proposed by D.G. Campbell

proposed that people with PDS often exhibits iris transillumination defects

iris transillumination defects (slitlike defects) – there was a corresponding packet of zonules attached to it.

MECHANICAL ABRASION THEORY

MECHANICAL ABRASION THEORY

MECHANICAL ABRASION THEORY

ABIOTROPHY THEORY

Abiotrophy is the premature degeneration of cells or tissues, especially when it is due to genetic defects

PDS might have a heritable component – GPDS1 gene mapped in chromosome 7

microscopic findings of iris tissue

EPIDEMIOLOGY

Diagnosed on second and third decade of life

PDS is equally prevalent among men and female, PG is more common among males

More common among whites

More common on myopic patients

Genetic association is under study

SYMPTOMS

EARLY: usually no symptoms; some may have blurred vision with jarring exercise

LATER: loss of peripheral vision

VERY LATE: loss of central vision

SIGNS

CORNEA

– KRUKENBERG SPINDLE – pigment deposited on the corneal endothelium and phagocytosed in the endothelial cells

– pigments do not cause visual symptoms– pigments do not harm the endothelium

SIGNS

IRIS

– develops defects in pigment epithelium of the iris that can be seen through transillumination

– pigments deposited on the anterior surface can cause iris to appear darker

SIGNS

PUPILS

– change in the function of the pupil– in asymmetric disease, larger pupil is found in the affected

eye

ANTERIOR CHAMBER

– anterior chamber is usually deep

SIGNS

IRIDOCORNEAL ANGLE

– open angle – densed trabecular pigment – backbowed iris

* gonioscopy is of importance to visualize the angle

SIGNS

POSTERIOR CHAMBER

– pigments can accumulate at the junction of the lens and posterior zonules

– SCHEIE STRIPE or ZENTMEYER LINES– best examined in dilated pupils– gonioscopy in of benefit

In Summary ...

Classic triad of clinical signs of PDS

– Krukenberg spindle– slitlike, radial, midperipheral iris transillumination

defects– pigment deposition on the trabecular meshwork

TREATMENT

Treated like POAG

Cholinergic agonist drugs (Pilocarpine) – induces miosis and lifts iris from the zonules

– not well tolerated by myopics– may increase risk for developing retinal detachment– pilocarpine Ocusert can be used to lessen side effects

TREATMENT

Laser Trabeculoplasty may be beneficial in PG

Laser Iridotomy – in PG patients with iris backbowing

Not an ideal choice in the following patients 1. Patients with PDS with no Ocular Hypertension and may never

develop optic nerve damage

2. Patients with advanced glaucomatous damage taking multiple medications

TREATMENT

Trabeculectomy – if medical and laser therapy fails

– increased risk for failure– antimetabolites should be used with caution– myopic males is at increased risk to develop hypotony

maculopathy

PROGNOSIS

25 to 50% of patients with PDS will progress to Pigmentary Glaucoma (PG)

6 to 8% of patients with PDS & PG will develop retinal detachment

THANK YOU!