Iris: Pigment Dispersion Syndrome

Question 1

pigment dispersion syndrome

Answer 1

liberation of pigment from the iris with subsequent accumulation on anterior segment structures

Question 2

pigment dispersion syndrome etiology/associations

Answer 2

• posterior bowing of midperipheral iris with the iris epithelium rubbing zonules
• possibly due to increased AC pressure relative to PC pressure
• mapped to a gene

Question 3

pigment dispersion syndrome demographics

Answer 3

• typically occurs between 20-50 years of age
• more common in Caucasian men
• more common in myopes
• associated with lattice degeneration in ~6-7% of cases- retinal holes and rhegmatogenous RD

Question 4

pigment dispersion syndrome laterality

Answer 4

bilateral

Question 5

pigment dispersion syndrome symptoms

Answer 5

• asymptomatic (majority)
• blurred vision, eye pain, and halos around lights after exercise of pupillary dilation- exercise or pupillary dilation can cause pigment release with acute elevation of IOP

Question 6

pigment dispersion syndrome signs

Answer 6

• posterior bowing of midperipheral iris, AC appears deep
• midperipheral, spoke-like iris TIDs
• pigment deposition: dark homogenous band on the trabecular meshwork,Sampaolesi line, Krukenberg spindle, Scheie line/stripe- pathognomonic for PDS, AC, anterior iris surface, anterior hyaloid face, ciliary body, zonules

Question 7

Sampaolesi line

Answer 7

pigment at or anterior to Schwalbe’s line

Question 8

Krukenberg spindle

Answer 8

vertical band of pigment on K endothelium

Question 9

Zentmayer line or Scheie line/stripe

Answer 9

pigment on posterior equatorial lens surface

Question 10

_____ is the only clinical tool that allows for visualization of TM pigmentation

Answer 10

gonioscopy

Question 11

transillumination defect characteristics

Answer 11

• peripheral iris, usually ~360 degrees
• seen with retroillumination
• can progress in size with progression of the disease

Question 12

pigment dispersion syndrome complications

Answer 12

• secondary open angle glaucoma: Pigmentary Glaucoma**
• clinical connections to iris cyst formation and myopia
• clinical connections to lattice degeneration (esp. with high myopia)
• higher risk of iris prolapse during cataract surgery

Question 13

pigmentary glaucoma

Answer 13

too much pigment in TM –> TM endothelial cells cannot phagocytize efficiently –> TM endothelial cells disintegrate –> pigment may obstruct the TM –> obstructs aqueous outflow –> increased IOP –> damage to optic nerve (glaucoma)

Question 14

pigment dispersion syndrome management

Answer 14

• SL exam with retroillumination- grade severity of pigment deposition on anterior segment structures
• check IOP (track for changes)
• gonioscopy- grade severity of pigment dispersion on anterior segment structures, perform at minimum annually
• A Seg photos
• monitor q6-12 months for PDS stability versus PDS induced glaucoma: pigmentary glaucoma

Question 15

how to evaluate for pigmentary glaucoma

Answer 15

• dilated fundus exam, annually- detailed exam of the optic nerve and peripheral retina
• ONH photos (not on Optos), baseline and then if you suspect optic nerve changes
• ONH OCT: RNFL, annually
• Ganglion Cell Complex, annually
• Visual Field (HVF): baseline with a 24-2 and then a 10-2 if needed, q6-12 months

Question 16

pigment dispersion syndrome treatment

Answer 16

• exception: if tolerated, miotics may be first line to minimize iridozonular contact
• laser peripheral iridotomy (LPI, PI) may also minimize iridozonular contact- equalizes the pressure between the anterior and posterior chambers and flattens the iris

Question 17

LPI complications

Answer 17

• pigment release into angle
• monocular diplopia
• inflammation

Question 18

pigmentary glaucoma treatment

Answer 18

• if glaucoma develops, treatment is similar to POAG
• topical eyedrop(s) to lower IOP- first line: beta blockers, alpha agonist, CAIs; second line: prostaglandin analogs, rho-kinase inhibitors (?)
• miotics (pilocarpine) may still be used- side effects may decrease patient adherence to routine
• selective laser trabeculoplasty (SLT)- laser treatment to the TM –> TM contracts –> opens angle –> increases aqueous drainage –> lowers IOP; becoming established as a first line treatment
• LPI- treatment of the iris approach, not really for IOP control

Question 19

PDS clinical pearls:

• _____ is the only clinical tool that allows for assessment of TM pigment
• _____ aid in viewing iris structure
• view the lens equator on SL exam by ____
• large fluctuations in IOP can occur, especially with ____
• risk of developing pigmentary glaucoma is _____
• PDS alone can be ____
• must evaluate for changes to ____
• PDS that includes pigmentary glaucoma must _____

Answer 19

gonioscopy;
UBM and ASeg OCT;
angling the slit beam nasally and having the patient look temporally (better assess zonules and Scheie stripe);
vigorous exercise;
10% at 5 years and 15% at 15 years;
monitored or treated (case by case decision);
visual field and optic nerve health;
be treated appropriately