Pigment Dispersion Syndrome

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Pigment (melanin) released from the mid-peripheral posterior iris surface and distributed around the posterior segment

Posterior bowing of the iris with rubbing against the zonules
Reverse pupillary block in some cases: increased AC pressure relative to PC leading to backward pressure on iris

Autosomal dominant inheritance (chromosome 7 and 18)

Risk factors

Pigment on the corneal endothelium: Krukenberg spindle
Pigment elsewhere: posterior lens capsule (Zentmayer’s line), anterior hyaloid-capsular ligament (Egger’s line), anterior lens along zonule insertions (Scheie stripe)
Spoke-like transillumination defects: mid-peripheral zone
Lattice degeneration: increased prevalence of retinal tears and detachments
Open angle with concave peripheral iris and homogenous pigmentation of the trabeculum on gonioscopy

As for POAG, however the NICE guidelines do not recommend SLT as first-line management in PDS patients
Miotics have theoretical benefit by reducing iridozonular contact but carry risk of inducing retinal detachment
PI is controversial in pigmentary glaucoma: no clear data to support routine use
- Typically avoided as poorly tolerated by young people and can worsen myopia