3. Bilateral,
Symmetric,
Non-inflammatory,
Opacifying ,
Inherited or genetically determined condition with
little or no relationship to environmental or systemic factors.
Most corneal dystrophies have an onset prior to age 20 years
(exceptions include map-dot-fingerprint dystrophy and Fuchs
corneal dystrophy)
Most corneal dystrophies are dominantly inherited, exceptions
being macular dystrophy, type-3 lattice dystrophy, and the
autosomal recessive form of congenital hereditary endothelial
dystrophy
4. Features Degeneration Dystrophy
Onset Presents later in life,
associated with aging
Present early in life,
hereditary
Laterality Unilateral Bilateral;
May be asymmetric
Bilateral & symmetric
Family history Uncommon Common
Vascularization Common Uncommon
Location often peripherally
located
Centrally located
Progression Progression can be very
slow or rapid
Progression usually slow
5. Classified according to
genetic pattern,
severity,
histopathological features,
biochemical characteristics or
anatomical location.
IC3D(International Committee for the Classification
of Corneal Dystrophies) established in 2005 has
revised the dystrophy nomenclature.
8. Also known as map-dot fingerprint
or Cogan microcystic dystrophy
Usually sporadic, may be AD
Most common dystrophy
Bilateral, more common in women
with increasing frequency over the
age of 50.
Onset in the 2nd decade
9. EBMD is an abnormality of epithelial turnover, maturation, and
production of basement membrane.
Thickened basement membrane with deposition of fibrillar
material between the basement membrane and Bowman’s
membrane.
Damaged sub-basal nerves causes reduced corneal sensation.
Epithelial microcysts with absent or abnormal
hemidesmosomes
10% develop recurrent epithelial erosions
10. Symptoms:
Due to recurrent
epithelial erosions
Pain on awakening
Blurred vision
Monocular diplopia
Image ghosting
13. Management:
• 5% NaCl drops or ointment
• Lubricating drops/ointment
• Epithelial debridement
• Patching
• BCL
• Phototherapeutic keratectomy
• Stromal puncture in recalcitrant cases using a 20-25G
needle(0.1 mm depth)- anterior micropuncture
Superficial keratectomy
diamond burr
PTK
excimer laser ablation
EBMD increases risk of failure of LASIK
14. Very rare epithelial dystrophy
AD with gene locus on 12q13 or 17q12: mutation in Corneal
Keratin K3 and K12.
Patients asymptomatic till 4th-5th decade
Cornea may be thinned and sensation reduced
Symptoms
may be asymptomatic or symptomatic in first few years of
life
-mild irritation & Decrease of vision.
-pain, redness, photophobia because of
recurrent erosions due to rupture of cysts
16. Epithelial microcysts consisting of
epithelial cell debris concentrated
centrally
Intracellular “peculiar substance”
Clusters of tiny round cysts in the
epithelium
extending out to the limbus
Most numerous in interpalpebral area
coalescence of cysts may form refractile
lines
Cornea may be slightly thinned and
corneal sensation reduced.
18. AD or X-linked on Xp22.3
Gray band shaped & feathery lesions
of densely crowded clear microcysts
appear in a whorled patterns.
Symptoms:
possible decreased VA,
no pain
Treatment: Usually none,
but sometimes corneal
debridement or RGP contact lenses
19. Autosomal dominant (keratoepithelin gene on
chromosome 5q31)
Manifests in first decade of life
Superficial gray white linear, geographic, ringlike
opacities at the level of Bowman’s layer comprising
of fibrous tissue.
Symptoms –
Onset in first 1-2 years of life
Pain, redness, photophobia, decreased vision due to
severe recurrent corneal erosions.
Corneal sensation is reduced.
21. Histology- Bowman’s layer is
completely replaced by masses of
disoriented collagen fibrils and
smaller electron dense fibrils
Leads to a reticular pattern in an
undulating, “sawtooth”
fashion, corresponding to
subepithelial opacities
22. Treatment
Symptomatic for corneal erosions
Superficial keratectomy
Lamellar keratoplasty
PTK
Rarely PK
Recurrence in the graft is common
23. The excimer laser utilises 193 nm ultraviolet light to disrupt
intermolecular bonds in the cornea by a process termed
"photoablative decomposition“
PTK allows the removal of superficial corneal opacities and
surface irregularities.
After adequate excision of scar tissue, the irregular corneal
surface masked using 2% methylcellulose to produce a more
uniform surface profile. Laser ablation performed using an
appropriately sized beam.
24. AD
Chromosome 10q24 and 5q31
(keratoepithelin gene)
Same pathogenesis and clinical
appearance as Reis-Bucklers
dystrophy but with a more
honeycomb pattern, “curly
fibers” sub-epithelial fibrosis
Treatment: same
25. Very common
AD
Pathogenesis:
Amyloid deposits concentrated in anterior stroma and
subepithelial areas poor epithelial-stromal adhesions
leading to recurrent corneal erosions
Stains orange-red with Congo Red dye and exhibits
characteristic green birefringence when viewed through
polarizing filter. Also stains with Massons trichrome and PAS.
26. Central and subepithelial white dots
Refractile lines, or “lattice lines,” best seen
on retroillumination
Diffuse anterior stromal haze
Clear peripheral cornea
27. Classic lattice dystrophy
Chromosome 5q31 (Keratoepithelin gene)
Onset at end of first decade with recurrent
erosions preceding stromal changes
Corneal sensation is reduced
Treatment:
Soft contact lenses to prevent recurrent erosions
PK or DLK usually needed by sixth decade
Recurrence in graft is common
28. Histology shows amyloid
staining with Congo red
Green birefringence with
polarized light
Glassy dots in ant. Stroma
Fine lattice lines seen on
retroillumination
Prominent lattice lines and
stromal haze
Periphery is spared.
29. Associated with systemic
amyloidosis
Chromosome 9q34
Onset third decade with recurrent
erosions
more delicate, sparse, radially
oriented lattice lines, which are
more peripherally & spread
centripetally from limbus.
Increased risk of Glaucoma
Central cornea spared & corneal
sensations are reduced
Treatment: same as type I
Extraocularly, amyloid is detected in arterial walls, peripheral nerves, and glomeruli.
30. Systemic features:
progressive cranial and peripheral neuropathy
Dysarthia
Dry and lax itchy skin,
Protruding lips
Pendulous ears
Lagophthalmos
• Bilateral facial palsy may be seen mask-like facies
31. Type III is AR, IIIa is AD
Chromosome 5q31
Onset between fourth and
sixth decade
Thick, ropy lines with
minimal intervening haze.
No spontaneous corneal
erosions
Rapid progression if
subjected to trauma
Treatment : PK or DLK
32. AD
chromosome 5q31-keratoepithelin gene
Hyaline deposits that stain red with Masson trichrome stain
Histochemically, the deposits are noncollagenous protein that
may be derived from the corneal epithelium and/or keratocytes.
33. Seen as sharply demarcated irregular
deposits resembling crumbs or snowflakes
in the central anterior stroma, often
distributed in a radial fashion.
The lesions do not extend to the limbus but
can extend anteriorly through focal breaks in
Bowman layer.
Patients complain of glare and photophobia.
Recurrent erosions may occur and vision
decreases as the opacities become more
confluent.
sensation becomes impaired
34. Histology shows amorphous
hyaline
deposits that stain red
with Mason trichrome
Treatment: PK or DALK by
age 40-50
Superficial recurrences
treated with excimer laser
keratectomy
35. AKA granular-lattice dystrophy
Older patients have stromal haze between
deposits leading to reduced VA
Both hyaline deposits typical of granular
dystrophy and amyloid deposits
characteristic of lattice dystrophy
These extend from the basal epithelium to
the deep stroma.
Stellate, snowflake-like opacities appear
between the superficial and mid stroma.
36. Management :
PTK, LK, or PK may be useful, depending on the depth of the
deposits.
LASIK and LASEK may result in increased opacification and
are contraindicated.
37. Least common dystrophy
Autosomal recessive
(chromosome 6)
Systemic inborn error of keratan
sulphate metabolism seems to
have only corneal manifestations
Multiple, gray-white opacities
that are present in the corneal
stroma and extend into the
peripheral cornea
Stromal opacities are distributed
throughout the cornea without
clear spaces.
38. Symptoms- progressive loss of
vision, pain, photophobia
Histology- glycosaminoglycan
deposits within stromal
keratocytes
Treatment
Lamellar/penetrating
keratoplasty
39. Rare, slowly progressive
AD, chromosome 1p36
Onset as early as first year
of life, but diagnosis
usually not made until
second or third decade
Local disorder of corneal
lipid metabolism
Associated with increased
serum cholesterol in 50%
of patients
40. Central oval subepithelial opacities (unesterified and
esterified cholesterol)
Central corneal opacification
Dense corneal arcus lipoides
Decreased corneal sensation
Management: Check lipid profile, PK, PTK for
subepithelial crystals
Recurrence can occur after PK
41. Primary familial amyloidosis
Uncommon
AR, Chromosone 1p
Onset first decade
Subepithelial and ant stromal amyloid deposition
Severe photophobia, tearing, visual impairment
42. Gradual confluence giving rise to
protruding,mulberry-like
appearance
Treatment:
superficial keratectomy or PK
VERY high recurrence rate in
graft
43. AD
Very slowly progressive
Unknown cause, possibly due to
deposition of
mucopolysaccharide and lipid
Opacities densest centrally
Multiple nebulous, polygonal
gray areas separated by gray
crack-like clear zones
Theses opacities are densest
centrally and posteriorly and
fade both anteriorly and
peripherally.
Management: none needed as
vision is usually not reduced
45. Characteristics Granular Macular Lattice
Inheritance AD AR AD
Age of onset of
symptom
3rd decade 1st decade 1st decade
Epithelial
erosions
Mild Mild – Moderate Severe
Nature of deposit Hyaline GAG Amyloid
Corneal deposits Small discrete ,
clear zone in
between, never
reaches limbus
Irregular
margins, no clear
zones, reaches
limbus
Refractile lines &
dots with central
haze, may
involve limbus
46. Characteristics Granular Macular Lattice
Opacities Grayish opaque
granules, ‘Bread-
crumbs’ sharp
borders
Grayish opaque
spots, indistinct
borders
Grayish ‘pipe
cleaner’ linear
branching threads
Histochemistry Masson : brilliant
red
Alcian blue : +
Colloidal iron:+
Masson : red
purple
Congo red: +
PAS: +,
Thioflavin- T fluro
: +
Defect Hyaline
degeneration of
collagen
Defective
mucopolysccharid
e metabolism
Primary
amyloidosis of
cornea
47. Very common
May be AD but majority are sporadic
Female preponderance
Onset after age 50
Ranges from asymptomatic guttata to a decompensated cornea
with stromal edema, subepithelial fibrosis, and epithelial bullae
48. Pathogenesis Abnormal production of collagenous material by
the affected endothelial cells causes marked thickening of
descemet’s membraneguttae
Increased corneal edema and deposition of collagen and
extracellular matrix in Descemet’s membrane
reduction in Na, K-ATPase pump sites and/or function
49. Hypothesis
Abnormal final differentiation of neural crest cells – mutation
in collagen producing gene COL8A2
Increased incidence in female – role of hormone in
pathogenesis
Alteration in the composition of aqueous humour
Mitochondrial abnormalities – endothelial Na-K pump requires
tremendous energy which is gained from mitochondria
50. Stage 1: asymptomatic, central corneal guttae with fine
pigment dusting, vision and corneal thickness normal
Stage 2: stromal edema, painless decreased vision(esp upon
awakening),glare and haloes,
specular microscopy – pleomorphism & polymegathism,
increased corneal thickness on pachymetry
Stage 3: Persistent epithelial edema leading to microcysts and
bullae which cause pain upon rupture
Stage 4 – growth of avascular subepithelial connective tissue,
scarring, pain diminished but severely reduced vision
51. (A)Histology of cornea guttata
shows irregular excrescences
of Descemet membrane – PAS
stain;
(B)cornea guttata seen on specular
reflection;
(C) ‘beaten-bronze’ endothelium;
(D) bullous keratopathy;
(E) histology shows severe
epithelial oedema with surface
bullae – PAS stain
52. Check pachymetry and specular microscopy (cell count)
Treatment:
– Reduce edema with NaCl 5% drops
– Lower IOP
– BCL to protect exposed nerve endings
– PK- high success rate, or DSEK
53. Autosomal dominant
Onset – 2nd-3rd decade(congenital variant
manifests at birth)
Clinical features
vesicular lesions, band lesions, diffuse
opacities on descemet’s membrane
Corneal edema, irido corneal adhesions,
corectopia, glaucoma
54. Histology – epithelialisation of endothelium ,
metaplasia of endothelial cells into fibroblast,
pleomorphism and degeneration of endothelial cells,
thickening of descemet’s membrane
Treatment – penetrating keratoplasty
55. Rare dystrophy in which there is focal or generalized
absence of corneal endothelium
AD on 20p11 or AR on 20p13
Onset is perinatal
Cornea may range from blue-gray with ground glass
appearance to total opacification and thus variable visual
impairment
Two forms CHED 1 & 2
56. CHED 1 CHED 2
Autosomal dominant
(chr 20)
Autosomal recessive
Clear cornea at birth Corneal clouding at birth
Photophobia and epiphora
common
No Photophobia and epiphora
Vision better Vision poor
Nystagmus uncommon Nystagmus common
57. Histology – deposition of
abnormal collagen layer
containing disorganised
collagen fibrils with
interspersed basement
membrane like material
Treatment – penetrating
keratoplasty
58. EBMD
Meesmann epithelial dystrophy
Reis Buckler dystrophy
Schnyder central crystalline dystrophy
Lattice dystrophy
Granular corneal dystrophy type I
59. EBMD
Reis Bucklers Dystrophy
Thiel Behnke Dystrophy
Lattice Corneal Dystrophy type I
UNCOMMON
Lattice corneal dystrophy type II
Granular corneal dystrophy type I and II
Editor's Notes
These are usually best seen with sclerotic scatter, retroillumination, or a broad tangential beam.
Four kinds of lesions are seen in the epithelium and its immediately subjacent basement membrane:
1. fingerprint lines
2. map lines
3. dots or microcysts
4. bleb or cobblestone-like pattern
Fingerprint lines are thin, relucent, hairlike lines; several of them
are often arranged in a concentric pattern so they resemble fingerprints.
Map lines are the same as fingerprint lines except thicker, more irregular, and surrounded by a faint haze;
they resemble irregular coastlines or geographic borders on maps (Fig 10- I).
Maps and fingerprints consist of thickened or multilaminar strips of epithelial basement membrane.
Dots (in Cogan microcystic epithelial dystrophy) are intraepithelial spaces containing the
debris of epithelial cells that have collapsed and degenerated before having reached the
epithelial surface
DLK -Deep lamellar keratoplasty
DLK -Deep lamellar keratoplasty
The mutated gelsolin is seen deposited in
the conjunctiva, sclera, and Ciliary body, along the choriocapillaris, in the ciliary nerves
and vessels, and in the optic nerve. Extraocularl y, amyloid is detected in arterial walls, peripheral
nerves, and glomeruli. On confocal microscopy, depOSits are seen along the basal
epithelial cells and stromal nerves.
Granular dystrophy type 1.
(A) Histology shows red-staining material with Masson trichrome;
(B) sharply demarcated crumbs;
(C) increase in number and outward spread;
(D) confluence
Fuchs endothelial dystrophy.
Histology of cornea guttata shows irregular excrescences of Descemet membrane – PAS stain;
cornea guttata seen on specular reflection;
‘beaten-bronze’ endothelium;
bullous keratopathy;
histology shows severe epithelial oedema with surface bullae – PAS stain
Congenital hereditary endothelial dystrophy.
Bilateral perinatal corneal opacification;
mild;
very severe