PIGMENT DISPERSION SYNDROME

1. PIGMENT DISPERSION
SYNDROME
DR ARPITA

2. INTRODUCTION
• A form of secondary open-angle glaucoma
characterized by dispersion of pigment granules
from the iris pigment epithelium, with deposition
throughout the anterior segment

3. ANATOMY

5. HISTORY
• In 1940, Sugar briefly described one such case with
marked pigment dispersion and glaucoma 1
• In 1949, Sugar and Barbour reported the details of this
entity, which differed from other forms of pigment
dispersion by typical clinical and histopathologic
features. They referred to the condition as pigmentary
glaucoma 2
1.Sugar HS. Concerning the chamber angle. I. Gonioscopy. Am J Ophthalmol
1940;23:853-866.
2. Sugar HS, Barbour FA. Pigmentary glaucoma: a rare clinical entity. Am J Ophthalmol.
1949;32(1):90-92.

6. • The mechanism of the pigment dispersion was
suggested by Campbell in 1979 to be a rubbing of iris
pigment epithelium against packets of lens zonules,
which results from a posterior bowing of the peripheral
iris.[3]
3.. Campbell D.G.: Pigmentary dispersion and glaucoma: a new theory. Arch
Ophthalmol 1979; 97:1667-1672

7. TERMINOLOGY:
• Pigment dispersion syndrome (PDS):
• Dispersion of iris pigment throughout the eye. PDS can
lead to ocular hypertension (OHTN) or glaucoma and is
usually bilateral.
• Pigmentary glaucoma (PG):defined as glaucomatous
optic neuropathy attributable to elevated intraocular
pressure (IOP) from PDS

8. EPIDEMIOLOGY
• Pigmentary glaucoma roughly constitutes 1% to 1.5% of
all glaucomas
• Onset usually occurs before age 40 years
• The disease preferentially involves men (M:F=2:1) and
the women affected usually are a decade older than the
men
• Pigmentary glaucoma occurs most often in white
individuals: it is diagnosed rarely in blacks and Asians
• Strong association between pigmentary glaucoma and
myopia
Typical patient is a young white myopic male

9. • The diagnosis of elevated IOP at a young age should
prompt the examiner to search for a cause.
• Usually bilateral
• No typical hereditary pattern is known in PDS. Most of
the patients are sporadic in nature. However autosomal
dominant and autosomal recessive patterns are also
reported
• There is a significant linkage between the disease
phenotype and genetic markers located on 7q 35-36
• Probability of converting to pigmentary glaucoma is 10%
at 5 years and 15% at 15 years *
Siddiqui Y., Hulzen R.D.T., Cameron J.D., et al: What is the risk of developing pigmentary glaucoma
from pigment dispersion syndrome?. Am J Ophthalmol 2003; 135:794-799

10. PATHOGENESIS
• Anatomical predisposition
• Myopia
• Deep AC
• Posterior insertion of the iris into the ciliary body
• Relatively larger iris contributing to its concavity
• Patients with pigment dispersion syndrome and
pigmentary glaucoma have revealed focal atrophy,
hypopigmentation, and apparent delayed melanogenesis
of the iris pigment epithelium-inherent weakness in the
iris pigment epithelium
Scheie HG, Fleischhauer HW. Idiopathic atrophy of the epithelial layers of the iris and ciliary body:
a clinical study. Arch Ophthalmol. 1958; 59(2):216-228.

11. • The configuration of the eye in these patients, as
described above, appears to favor a “pumping” action of
the iris, in which eye movement, as with blinking, causes
the peripheral iris to act as a bellows in forcing aqueous
from the posterior to the anterior chamber.
• This results in a reverse pressure gradient, i.e., higher in
the anterior than posterior chamber. The iris then acts as
a one-way valve against the lens, preventing aqueous
from returning to the posterior chamber.
• The increased pressure in the anterior chamber leads to
posterior bowing of the mid-peripheral iris and
consequently to the rubbing of the iris pigment
epithelium against packets of lens zonules, with
liberation of pigment granules into the aqueous.
•

12. REVERSE PUPILLARY BLOCK

13. • Accommodation in patients with PDS
• It has been observed that accommodation in patients
with PDS leads to increased posterior bowing of the iris,
which the investigators explain by the forward movement
of the lens, which reduces the volume, thereby
increasing the pressure in the anterior chamber.
Iridotomy abolishes the change in patients with PDS.
• Blinking
• Campbell proposed that blinking initially deforms the
cornea, transiently increasing IOP and pushing the iris
posteriorly against the lens

15. • Once the pigment granules are released from the iris
pigment epithelium into the aqueous, some of them find
their way to the trabecular meshwork, where the
remainder of the mechanism leading to elevated IOP
occurs.
• The trabecular endothelial cells engulf the pigment,
which eventually leads to cell injury and death from
phagocytic overload.
• Macrophages carry off the pigment and debris, leaving
the denuded collagen beams to collapse and fuse,
with obliteration of the outflow channels. This may
explain why treatments directed at trabecular outflow,
such as laser trabeculoplasty, are more effective in the
earlier stages of pigmentary glaucoma

16. CLINICAL FEATURES
SYMPTOMS
• Early: asymptomatic
• Later: loss of peripheral vision
• Advanced: loss of central vision
• Episodes of pain/blurred vision with haloes following
strenuous exercise

17. SIGNS
• 1) CORNEA
• Pigment deposition on the endothelium, in a vertical
spindle-shaped distribution (Krukenberg spindle)

18. • KRUKENBERGS SPINDLE:
• Neither universal nor pathognomonic of PDS ( can also
occur in trauma ,uveitis )
• Tends to be slightly decentered inferiorly and wider at its base
than its apex.
• Generally appears as a central, vertical, brown band up to 6
mm long and up to 3 mm wide.
• With time, it becomes smaller and lighter and often requires
careful examination to identify it.
• Common in women
• May have a hormonal relationship
• Normal central corneal thickness

19. • Studies of fluid dynamics show that there is a vertical
circulation current of aqueous humor in the anterior
chamber.
• This is hypothesized to result from a temperature
gradient from the posterior portion of the anterior
chamber (warmer, causing fluid to rise) to the anterior
portion of the anterior chamber (cooler, causing fluid to
fall).
• Deposition of circulating pigment onto the corneal
epithelium gives rise to the vertical Krukenberg spindle.
• The spindle consists of extracellular as well as
intracellular pigment granules phago-cytized by the
corneal endothelium

20. 2) ANTERIOR CHAMBER
• Anterior chamber is very deep and melanin granules
may be seen floating in the aqueous
• Posterior bowing of the peripheral iris.

21. • IRIS
• Pigment epithelial atrophy due to shedding of pigment
from the mid-periphery gives rise to characteristic radial
slit-like/spoke like transillumination defects

22. • In black patients, signs of PDS may be overlooked
because dark, thick iris stroma may obscure
transillumination defects and pigment granules on the
stroma; corneal endothelial pigmentation may be
minimal or absent; and greater degrees of trabecular
meshwork pigmentation may be interpreted as
normal in black patients.
• It has been suggested that pigment accumulation on the
lens zonules and equatorial or posterior lens regions
may be particularly helpful in making the diagnosis of
PDS in black patients
• Frequent dispersion of pigments on the stroma of iris
may give the iris a progressively darker appearance and
create heterochromia in asymmetric cases

23. • Fine surface pigment granules that may extend onto the
lens; partial loss of the pupillary ruff (frill)
• Patients with PDS may also have anisocoria, in which
the eye with the larger pupil is on the side with the
greater iris transillumination. The iris heterochromia and
anisocoria of PDS may mimic Horner syndrome
Jack J Kanski, Brad Bowling, Seventh Edition

24. GONIOSCOPY
• The angle is wide open and there is a characteristic
mid-peripheral iris concavity that may increase with
accommodation
• Sometimes reveals more posterior iris insertion along
with greater than expected iris processes

25. • Trabecular hyperpigmentation is most marked over the
posterior trabeculum
• The pigment is finer than in PXF
• Appears to lie both on and within the TM
• In older patients, in whom the trabecular meshwork
begins to recover and the pigment gradually clears, the
pigment band may become darker superiorly more than
inferiorly, a pattern referred to as the pigment reversal
sign

26. • LENS
• May occassionally show a line or an annular ring of
pigment on the peripheral posterior surface - Scheie
stripe or Zentamayer ring
• Gonioscopy with pupillary dilatation will demonstrate this
interrupted line of pigment which is otherwise difficult to
see on routine slit lamp examination.
• As lens thickness increases with age, “ burnout " can
occur, because the iris is displaced sufficiently to prevent
further release of pigment from zonular abrasion.

29. FUNDUS FINDINGS
• Increased risk for retinal detachment, which may occur
in as many as 6-7% of individuals
• Retinal breaks and lattice degeneration (20%) may
occur twice as frequently in these eyes

30. CLASSIC DIAGNOSTIC TRIAD
• Krukenberg spindle
• Midperipheral iris transillumination defects
• Dense trabecular pigmentation

31. NATURAL HISTORY
• Active phase
• The mean age at onset of PDS remains unknown but is
probably in the mid 20s. The development of PDS later
in life is unlikely because of gradual lens enlargement
and loss of accommodation.
• Regression phase: The severity of involvement of
both PDS and PG decreases in middle age, when
pigment liberation ceases, at least in the majority of
patients.

33. D/D

34. 1) POAG
May be associated with a hyperpigmented trabeculum.
However, the pigment tends to be concentrated in the
inferior sector of the angle, in contrast to the
homogeneous distribution in PDS.
Patients with POAG are also usually older and lack
Krukenberg spindles and iris transillumination defects.

35. • 2 ) Pseudoexfoliation
• May exhibit trabecular hyperpigmentation and pigment
dispersion.
• However, transillumination defects are evident at the
margin of the pupil rather than in the periphery
• Pseudoexfoliation glaucoma usually affects patients over
the age of 60 years, is unilateral in 50% of cases and
has no predilection for a myopic refractive error.

36. • 3) Pseudophakic pigmentary glaucoma
occurs in the context of rubbing of the haptics and optics
of a posterior chamber intraocular lens against the
posterior surface of the iris, with resultant pigment
dispersion and outflow obstruction.
•
4) Anterior uveitis may result in trabecular
hyperpigmentation and iris atrophy. Clustered old
pigmented keratic precipitates may be mistaken for a
Krukenberg spindle on cursory examination.
•
5) Subacute angle-closure glaucoma may be
associated with a heavily pigmented trabeculum where
the iris root has been in contact with the angle.

37. PDS XFN
DEMOGRAPHY 30-50 years
(a decade younger)
Men Related to myopia
Pigmented race
60-70 years
Common in women,
glaucoma more in men
Scandinavian countries
LATERALITY Bilateral disease: 90% Bilateral disease: 30%
PATHOLOGY Posterior bowing of iris
Constant rubbing of
posterior pigment iris and
zonules
Release of pigments
Trabecular block
Systemic disease of
abnormal
basement membrane
Secretion of amyloid-like
material
(oxytalon) in AC
Deposit in zonules and
trabeculum
Trabecular block

38. CLINICAL
FEATURES
Krukenberg’s spindle
Deep AC, with iris bowing
posteriorly (reverse
pupil block) .
Iris atrophy in periphery of
iris
Pigment deposit on lens
Pseudoexfoliative material,
dandruff-like
appearance throughout AC
Pupil difficult to dilate
Iris atrophy at edge of pupil
margin (Moth
eaten transillumination
defect)
Deposit on lens is
characteristic (target
likeappearance, called
hoarfrost ring)
Len subluxation (weak
zonules)
GONIOSCOPY heavily pigmented over
wide, open
angle
queer iris configuration
Sampaolesi’s line
(pigmented line anterior to
Schwalbe’s line)
Pseudoexfoliative material
PROGNOSIS Glaucoma risk: 10%
Good prognosis
Glaucoma risk: 1% per year
(5% in 5 years,
15% in 15 years)
Fair prognosis

39. INVESTIGATIONS
• UBM shows the posterior iris insertion,iris
concavity, iridozonular contact.

40. TREATMENT
• Medical treatment is similar to that of POAG.
• The treatment typically begins with medical therapy, and
all ocular hypotensive medications for open-angle
glaucoma are effective in these patients- PG analogues
are drug of choice
• Miotics would theoretically be of particular benefit
because they decrease iridozonular contact in addition to
facilitating aqueous outflow.
• They have the disadvantages, however, of exacerbating
the myopia common in these patients and also of a
risk of precipitating retinal detachment in myopia.
They are not well tolerated by young patients.

41. • Physical Activity
• Exercise may increase pigmentary dispersion and
elevate the IOP, which can be a concern in this
population of young, active individuals
• .One approach to dealing with this question is to
measure the IOP (and observe the amount of pigment in
the anterior chamber) before and 30 minutes after the
patient's typical exercise routine.
• If a significant pressure rise is observed, the use of
pilocarpine, 0.5%, during exercise may be beneficial

42. • 2 Laser trabeculoplasty
• The heavy trabecular pigmentation allows increased
absorption of laser energy, in turn allowing lower energy
levels for trabeculoplasty.
• Ritch et al reported 80% success rate of ALT at the end
of one year follow up.
• It causes trabecular tightening and expansion of
intertrabecular spaces. It may also lead to increase in
number and/or function of endothelial cells . A just visible
reaction in trabecular meshwork is required for adequate
treatment.

43. • 3) Laser iridotomy has been proposed to retard
pigment liberation by reversing iris concavity and
eliminating iridozonular contact. It may have utility in
patients under the age of 40 years but benefit has not
been conclusively demonstrated.

44. • 4 )Trabeculectomy
• When medical therapy and laser trabeculoplasty have
failed to adequately control the IOP, glaucoma filtering
surgery is usually indicated
• Filtering surgery is usually successful; however, extra
care is warranted, because young patients with myopia
may be at increased risk of hypotony maculopathy.
• Use of adjunctive antimetabolites may improve surgical
outcome.

45. PROGNOSIS
• Over time the control of IOP becomes easier and
occasionally the IOP may spontaneously revert to
normal; this may or may not be associated with a
decrease in trabecular pigmentation.
• Patients with undetected previous pigmentary glaucoma
may later be erroneously diagnosed as having NPG.