1. The document discusses various types of corneal dystrophies, including epithelial, stromal, and Descemet membrane dystrophies. 2. Corneal dystrophies are classified based on which layer of the cornea is affected and their clinical, pathological, and genetic characteristics. The International Committee for Classification of Corneal Dystrophies provides the current classification system. 3. Specific dystrophies discussed include epithelial basement membrane dystrophy, epithelial recurrent erosion dystrophy, Reis-Bucklers corneal dystrophy, Thiel-Behnke corneal dystrophy, lattice corneal dystrophy types 1 and 2, and granular corneal dystrophy type 1. Details are provided on inheritance patterns, genetic causes

1. Moderator:- Dr. N. Kori
Presenter:- Dr. Jyoti Gontia
RSO1
Upgraded
Department
Of
Ophthalmology

3.  Corneal dystrophies are
• progressive
• non-inflammatory
• Hereditary (except epithelial basement membrane
dystrophy)
• bilateral,
• non-vascularized ,
• Painless (except ERED )
• corneal opacities.
 They mainly affect a particular layer of the cornea.
 The International Committee for Classification of Corneal
Dystrophies (1C3D) established in 2005 has devised a
current and accurate nomenclature supplementing the
anatomic classification with updated clinical, pathologic
and genetic information.

4. Based on biomicroscopical and
histopathological features they are classified
into:-
 epithelial,
 Bowman layer,
 stromal, and
 Descemet membrane and endothelial.
One or more underlying genetic
abnormalities have been identified for most.

5. International committee for classification of corneal dystrophy 2015
 WHAT WAS ADDED
 1.New clinical,
histopathologic and
confocal photographs were
added
 2. Epithelial recurrent
erosion dystrophy included
 3. TBCD only on chr 5q31
 4.Updated anatomical
classification more
accurately classifying
TGFB1 dystrophies.
 WHAT WAS REMOVED
 1. AD CHED or CHED 1
 2. Grayson Wilbrandt
dystrophy
 3. Info on genetic mutation
removed
 4. 10q23-24 dystrophy not
included as a variant of
TBCD

6. Dystrophy gene mutation
Category 1 (C1) well-defined mapped known
Category 2 (C2) well-defined mapped unknown
Category 3 (C3) well-defined Not mapped
Category 4 (C4) Suspected new, previously documented , however
evidence for it being a distinct entity is not yet
convincing
Ref:- www.corneasociety.org/publications/ic3d
volume27 , suppl2, december 2008 IC3D classification of corneal dystrophy
Weiss et al

7. Rref: Weiss JS, Møller H, Lisch W, et al. The IC3D classification of the corneal dystrophies. Cornea 2008;27:S1–S42, S4

11. INHERITANE GENETIC LOCUS GENE ONSET
1. Epithelial basement
membrane dystrophy
(EBMD)
Majority sporadic;AD 5q31 TGFB1 Adult
2. Epithelial recurrent
erosion dystrophies
(EREDs)
AD Unknown unknown Early
childhood
3. Subepithelial mucinous
corneal dystrophy (SMCD)
AD unknown unknown 1st decade
(aldolescence)
4. Meesmann corneal
dystrophy (MECD)
AD Chr 12q13 (KRT3)
17q12(krt12)
Keratin 3
and 12
Early
childhood
5. Lisch epithelial corneal
dystrophy (LECD)
XLD Xp22.3 unknown childhood
6. Gelatinous drop-like
corneal dystrophy
AR Chr 1p32 Tumor asso.
Ca signal
transducer2
1st to 2nd
decade

12. 1.Epithelial basement membrane
dystrophy
 Epithelial basement membrane
(map-dot-fingerprint) is the most
common corneal dystrophy.
 Familial cases have been
reported. While most cases are
sporadic or arise from superficial
trauma, a subset of patients have
been linked to mutations in the
TGFBI gene on chromosome 5q31.
 Despite this, it is often
misdiagnosed, principally due to
its variable appearance

13.  Typically, there are no signs until adulthood, when
following appears:-

14.  Other than map dot and fingerprint
Bleb pattern: is also seen which is Irregular,
subepithelial accumulation of a fibrillogranular
material
 Symptoms:- due to Episodic spontaneous
erosions which produce
• lacrimation
• glare
• blurred vision
 Onset is in the second decade. About 10% of
patients develop recurrent corneal erosions in
the third decade and the remainder are
asymptomatic throughout life.

15.  Histology
shows thickening of the basement membrane
with deposition of fibrillary protein between the
basement membrane and the Bowman layer.
Basal epithelial cell hemidesmosomes are
deficient.
 Treatment of epithelial basement membrane
dystrophy:
• lubricating ointments at bedtime and patching
• Excimer laser phototherapeutic
keratectomy(PTK) : for recurrent erosions

16. 2.Epithelial recurrent erosion dystrophy
 The autosomal dominant ERED has an
early onset in the first decade of life.
 Age of onset: Childhood
 The genetic locus and genes are not
known.
 Recurrent erosions occur spontaneously or
after minimal trauma.
 symptoms
• A subepithelial haze may be present
• Redness
• photophobia,
• Epiphora
• and ocular pain

17.  Course :Attacks generally
decline in frequency and
intensity and cease by the
age of 50 years.
 But, In the Smolandiensis
variant, central subepithelial
opacities will progress.
 On light microscopy
bowmans layer is partially
destroyed and pannus
develops between basal
layer and bowmans.

18.  Management and treatment
• Lubrication. This is considered first-line therapy
• Antibiotics and pain relievers.
• Cycloplegics
• Hypertonic saline
• Bandage soft contact lens
• For patients with lesions in the visual axis,
debridement and superficial keratectomy may be
performed
• and, in the Smolandiensis variant, dystrophy may
be prominent enough to require corneal
transplantation.

19.  3.Subepithelial mucinous corneal
dystrophy (SMCD)
• Rare
• bilateral
• subepithelial haze
• involving the whole cornea but most
prominent in the center
• inheritance :-autosomal dominant
• gene that causing corneal dystrophy
has not been identified.
• Onset:-occur in the first decade of
life
 Management and treatment
Same as ERED

20. 4.Meesmann dystrophy
 Rare
 non-progressive abnormality of corneal
epithelial metabolism
 underlying which mutations in the
genes encoding corneal epithelial
keratins have been reported.
 Inheritance. AD. Mutations in the
keratin genes, keratin 3 (KRT3) on
chromosome 12q13 and keratin 12
(KRT12) on chr17q12 have been
implicated in MCD and MCD-Stocker-
Holt variant.
 Histology shows irregular thickening
of the epithelial basement membrane
and intraepithelial cysts.

21.  Symptoms
• Patients may be asymptomatic
• or there may be recurrent erosions
blurring Usually mild
 Signs
• The cornea may be slightly
thinned and sensation reduced.
• Myriad tiny intraepithelial cysts of
uniform size but variable density
are maximal centrally and extend
towards but do not reach the
limbus
On direct illumination
diffuse gray sup
opacity

22. • The lesions may appear as gray
cysts or clear vacuoles on
indirect illumination.
• In the Stocker-Holt variant of
MCD, the punctate epithelial
opacities stain with fluorescein
and fine linear whorls of
opacities may be present
 Treatment other than
lubrication is not normally
required.

23.  5.Lisch epithelial corneal
dystrophy (LECD)
 Localized gray punctate epithelial
opacities radiate from the limbus
to the center of the
 cornea in flame, band, or feather-
like whorls in individuals affected
with LECD.
 Patients are generally
asymptomatic unless the opacities
extend to the central cornea.
 The inheritance pattern is X-linked
dominant with a locus at Xp22.3.
 However, the disease-causing gene
in this locus has not yet been
identified.
Lisch – grey bands with a
whorled configuration
Lisch – retroillumination shows
densely crowded microcysts;

24.  Light Microscopy-Diffuse
cytoplasmic vacuolization of all cells
in the affected area.
 Transmission Electron Microscope-
Extensive vacuolization of the
cytoplasm of the affected corneal
epithelium.
 Immunohistochemistry Scattered
staining on Ki67
immunohistochemistry indicates no
evidence of increased mitotic
activity
 m/m : lubricating ointments, soft
contact lens

25.  Onset is within 1st & 2nd decades
 AR, Chr 1p32, gene- Tumor asso.Ca
signal transducer2
 symptoms
• severe photophobia
• Tearing
• decreased vision
 Signs -Initially, the subepithelial
lesions may appear similar to
• band-shaped keratopathy or
• there may be groups of small
multiple nodules, that is mulberry
configuration
• Later life large nodular
opacification
.

26.  Light Microscopy :-Subepithelial and stromal
amyloid deposits.
 Treatment
Repeated superficial keratectomy (repeated
every 2 years) because of early recurrences on
corneal grafts

27. II. Epithelial And Stromal TGF Beta1 Dystrophy

28. Inherita
nce
Gene locus Gene Onset
1.Reis Buckler CD
(CBD1)
AD 5q31 TGFB1
(Arg124Leu and
Gly623Asp)
krachmer
Childhood
2.Thiel Behnke
(CBD2)
AD 5q31 TGFB1 Early
childhood
3.a)Lattice CD 1
b)Lattice corneal
dystrophy, gelsolin
type
AD
AD
5q31 Type1:
Arg124Cys
gene GSN.
1st to 2nd
decade
ADULTS
4.Granular CD1 AD 5q31 Arg555Trp childhood
5.Granular CD2 AD 5q31 Arg124His

29.  1.Reis-Bücklers corneal dystrophy
(RBCD)
 First described by Reis and then by
Bücklers,[RBCD presents as
subepithelial reticular or geographical
opacities that focally elevate the
epithelium, appearing symmetrically
in both corneas around 4–5 years of
age.
 This may be categorized as an
anterior variant of granular stromal
dystrophy and is also known as
corneal basement dystrophy type I
(CBD1).
 Inheritance is AD; the affected gene
is TGFB1.
Reis–Bucklers dystrophy – typical
moderately
discrete geographical opacities

30.  Symptoms. Severe recurrent corneal
erosions in childhood. Visual impairment
may occur.
 Signs
• Grey–white geographic subepithelial
opacities, most dense centrally (Fig.),
increasing in density with age to form a
reticular pattern.
• Corneal sensation is reduced.
• Histopathology, Replacement of the
Bowman layer by connective tissue bands.
• electron microscopy, may be required for
definitive distinction from Thiel–Behnke
dystrophy in some cases.
 Treatment is directed at the recurrent
erosions. Excimer keratectomy achieves
satisfactory control in some patients.

31. 2.Thiel–Behnke corneal
dystrophy
 Also termed honeycomb-
shaped corneal dystrophy and
corneal basement dystrophy
type II (CBD2); features are
generally less severe than
Reis–Bücklers.
 Inheritance. AD; gene TGFB1
at locus 5q31.However,
another locus on chromosome
10 (10q23-q24) has recently
been identified.
 Histology. Bowman layer
‘curly fibres’ on electron
microscopy.

32.  Symptoms. Recurrent erosions in
childhood.
 Signs. Subepithelial opacities are
less individually defined than the
granular dystrophy-type lesions
seen in Reis–Bücklers dystrophy.
 They develop in a network of tiny
rings or RETICULAR honeycomb-like
morphology, predominantly
involving the central cornea.
 HISTOLOGY:-Subepithelial fibrous
layer replace bowmans giving
sawtooth appearance
 the gold standard for diagnosing
Reis-Bücklers or Thiel-Behnke is
TGFBI mutation screening.
 Treatment is not always necessary.
Reticular honeycomb pattern

33. REIS BUCKLERS THIEL BEHNKE
Recurrent corneal erosion are
more frequent
Less frequent
Irregular diffuse opacity with
clear interruption
Multiple flecks with reticular
formation, honeycombing
LM bowman destruction Subepithelial fibrous layer
replace bowmans giving
sawtooth appearance
Massons trichrome stains
keratohyaline
EM rodlike granules Subepithelial curly filaments
Confocal granular
hypereflective material
Sawtooth pattern

34.  3. Lattice corneal
dystrophy, TGFB1 type
 This is usually regarded as
the classic form of lattice
dystrophy.
 Inheritance. AD; gene
TGFB1, Arg124Cys mutation;
however, many other
mutations in TGFBI have also
been shown
 • Histology. Amyloid,
staining with Congo red and
exhibiting green
birefringence with a
polarizing filter.

35.  Signs
• Refractile anterior stromal dots coalescing
• into a relatively fine filamentous lattice(FIG. C) that
spreads gradually but spares the periphery
• A generalized stromal haze may progressivelyimpair
vision (FIG. D)
• Corneal sensation is reduced.
 Treatment by penetrating or deep lamellar
keratoplasty is frequently required. Recurrence is not
uncommon

36. 3b. Lattice corneal dystrophy,
gelsolin type
 Also known as LCD2 and Meretoja
syndrome, this is a systemic
condition rather than a true
corneal dystrophy.
 The amyloid in LCD2 is a mutated
form of gelosin that accumulates
in the cornea between the
epithelium and Bowman's layer. It
is also found in heart,kidney,
skin, nerves, vessel walls, and
various other tissues.
 AD disorder, gelsolin gene (GSN),
which is located on chromosome
9q34 and encodes an actin
modulating protein, is
responsible for LCD2

37.  • Histology shows amyloid deposits in
the corneal stroma.
 Ocular symptoms. Ocular irritation
and late impairment of vision;
erosions are rare.
 Ocular signs
• Sparse stromal lattice lines spread
centrally from the periphery.
• Corneal sensation is impaired.
 Systemic features.
• Progressive cranial and peripheral
neuropathy, mask-like facies and
autonomic features.
 Homozygous disease is rare but
severe.
 • Treatment. Keratoplasty may rarely
be required in later life.

38.  5.Granular corneal dystrophy,
type 1 (classic)
 • Inheritance. AD; gene TGFB1.
Homozygous disease gives
 more severe features.
 • Histology. Amorphous hyaline
deposits staining bright red with
Masson trichrome (Fig. A).
 Symptoms
• Glare
• Photophobia
• with blurring as progression
occurs.
• Recurrent erosions are
uncommon.

39.  •Signs
• Discrete white central anterior
stromal deposits resembling
sugar granules, breadcrumbs or
glass splinters separated by
clear stroma (Fig.B).
 Gradual increase in number and
size of the deposits with deeper
and outward spread, sparing the
limbus (Fig.C).

40. -Gradual confluence and diffuse
haze leads to visual
impairment (Fig.D).
- Corneal sensation is impaired.
•Treatment by penetrating or
deep lamellar keratoplasty is
usually required by the fifth
decade. Superficial recurrences
may require repeated excimer
laser keratectomy.

41.  6.Granular corneal dystrophy, type
2
 Also known as Avellino and combined
granular-lattice dystrophy.
 Inheritance. AD; gene TGFB1.
 Histology shows both hyaline and
amyloid.
 Symptoms. Recurrent erosions tend to
be mild. Visual impairment is a later
feature.
 Signs are usually present by the end
of the first decade.
 Fine superficial opacities progress to
form stellate or annular lesions (Fig.),
sometimes associated with deeper
linear opacities.
 • Treatment is usually not required.
Corneal trauma accelerates
progression; refractive surgery is
contraindicated.

42. III STROMAL DYSROPIES

43. INHERITANC
E
GENETIC LOCUS GENE ONSET
1.MACULAR CD AR 16q22 Carbohydrate
sulphotransferase 6 gene
childhood
2.Schnyder CD AD 1p36 UBIAD1- UbiA
phenyltransferase
domain containing 1
Late diagnosed
in 2nd 3rd
decade
3.CONG.
STROMAL CD
AD 12q21 decorin congenital
4.Fleck CD AD 2q34 PIKFYVE Congenital
5.POST.
AMORPHOUS
CD
AD 12q21.33 Del of keratocan,
lumican, decorin ,
epiphycan
1st week of life
6.CENTRAL
CLOUDY D of
francois
unknown 1st decade
7.PRE-
DESCEMENT CD
Not well
defined
Isolated – unknown
X linked icthyosis –
Xp22.31
Steroid sulphatase >30 yrs

44.  1. Macular corneal dystrophy
 Inheritance. Autosomal recessive (AR); gene
CHST6(Carbohydrate sulphotransferase );
 MCD is characterized by intracellular accumulation
of glycosaminoglycans (GAG) within the
keratocytes and endothelium, but not the
epithelial cells.
 Similarly, extracellular deposits of GAG are present
throughout the stroma and Descemet's membrane.
 Mutations in the carbohydrate sulfotransferase 6
gene (CHST6) on chromosome 16q22 produce most,
but not all, cases of MCD. Well over a hundred
different mutations have been identified and most
are either missense or nonsense mutations that
alter a single nucleotide of the CHST6 gene.
 However, insertions and deletions in and around
the coding regions of CHST6 have also been
detected.

45.  Histology: Aggregations of
glycosaminoglycans intra- and
extracellularly; stain with Alcian blue
and colloidal iron (Fig.A).
 Symptoms. Early (end of first
decade) visual deterioration;
recurrent erosions are very common.
 Signs
• Dense but poorly delineated greyish-
white spots centrally in the anterior
stroma and peripherally in the
posterior stroma (Figs B and C).
• There is no clear delineation
between opacities, which may be
elevated.

46. • Progression of the lesions occurs in
conjunction with anterior stromal
haze, initially involving the central
cornea (Fig. D).
• There is eventual involvement of
full-thickness stroma, extending to
the limbus with no clear zone.
• Thinning is a fairly early feature,
with late thickening from oedema
due to endothelial dysfunction.
• Sensation is reduced.

47.  There are three subtypes of MCD distinguished
by the presence of keratan sulfate (KS).
• In type I, there is no detectable keratan sulfate
in the cornea or serum.
• In type II, there are normal amounts of KS in
both cornea and serum.
• The third type, has KS in keratocytes, but not
in serum
 Treatment. Penetrating keratoplasty. Recurrence
is common

48.  This is a disorder of corneal lipid
metabolism, associated in some
patients with systemic dyslipidaemia.
The use of crystalline in the name is
no longer recommended as corneal
crystals are not a ubiquitous feature.
 Histology: Lipid, neutral globular fat
and cholesterol deposition in corneal
stroma
 Stains with oil red O or Sudan black
 • Inheritance. AD; gene UBIAD1.

49.  Signs: Bilateral gray, disclike
opacities
often central crystals may be
deposited in a geographic,
annular, or disciform pattern and
may extend to the deeper stromal
layers
 Symptoms: raised serum
cholesterol in 50% patients diffuse
corneal haze and prominent arcus
in 3rd deacde
 Treatment: lamellar or
penetrating keratoplasty

50. Diffuse clouding with flake
like opacity
Stromal lamellae
seperated from each
other in regular manner
•Only four families of this rare autosomal dystrophy have
been reported. CSCD is characterized by the presence of
diffuse, bilateral, tiny flakelike corneal opacities.
•The opacities are spread throughout the stroma. It is stable
or slowly progressive. The epithelium and endothelium
appear normal.
•Defects in the decorin (DCN) gene on chromosome 12q21.33
have been associated with two families with CSCD.

51.  4. François central cloudy
dystrophy/Fleck corneal dystrophy
 It is not certain that this entity is a
dystrophy; it may be clinically
 indistinguishable from the degeneration
posterior crocodile
 shagreen.
 • Inheritance. AD has been reported,
Mutations in the phosphatidylinositol-3-
phosphate/phosphatidylinositol-5-kinase
type III (PIP5K3) gene on chromosome
2q35
 • Symptoms. Almost always none.
 • Signs
 ○ Cloudy greyish polygonal or rounded
posterior stromal
 opacities, most prominent centrally
(Fig).
 • Treatment is not required.

53. •The characteristic sheets of diffuse
gray-white opacities of PACD are most
prominent in the posterior stroma.
•The opacity may be noted in early life
and may be congenital.
•The associated anterior abnormalities
of prominent Schwalbe line, fine iris
processes, iridocorneal adhesions,
corectopia, and anterior stromal tags
suggest that this may not be a true
dystrophy, but more appropriately
termed a mesodermal dysgenesis.
•PACD shows an autosomal dominant
inheritance pattern, but no
chromosomal locus or gene has been
identified.

54. • Corneal thinning and Flattening
• The possible congenital onset, lack of
progression and association with iris
abnormalities raises the possibility of
mesodermal dysgenesis rather than a true
corneal dystrophy
Deep stromal
opacity with some
peripheral extention
Decreased corneal
thickness
Colloid iron stain
positive in posterior
stroma

55. •Cracked ice appearance
•No chromosomal locus or disease-causing gene has
been identified
•Many of the publications referenced did not provide
documentation that the corneal disease was familial.
Consequently, it is entirely possible that these cases
reportedas CCDF might actually be posterior crocodile
shagreen
•only posterior stroma
•No need for any treatment

56. •PDCD associated with X-linked ichthyosis—Steroid sulfatase
(STS) deficiency
•The clinical and genetic features of PDCD have not been well
defined. No definite inheritance pattern has been described and
histopathologic studies have not been consistent.
•The corneal opacities have been described as fine, gray
opacities in the deep stroma of various shapes along with more
central, larger lesions. Typically, the vision is not affected and
the patients are without symptoms.
• No chromosomal locus or causative gene has been identified
and there is debate as to whether PDCD is best described as a
dystrophy or as a degeneration
Punctate opacity anterior to BM

58. TYPE OF
DYSTROPH
Y
INHERE
TENCE
ONSET PATTERN GENE TREATMENT
1.Fuch’s
CD
AD 4TH- 5TH DECADE Guttata with
corneal edema
COL8A2 BSCL,
hypertonics,
DSAEK,
keratoplasty
2.POST.
POLYMORP
HOUS CD
AD 1ST DECADE Vesticular
lesion of
posterior
cornea
1 Unknown BSCL,
hypertonics,
keratoplasty2 COL8A2
3 ZEB1
3.CONG.
HERIDITARY
ENDO. D
AR Birth or 1st
year
Clouding of
cornea
SLC4A11 Penetrating
keratoplasty
4.XECD XLR
(severe
in
males)
birth Endothellial
alterations
resembling
moon craters
PTK, DLEK,
DSEK, DSAEK

59. 1.Fuchs endothelial corneal dystrophy
 This disorder is characterized by
bilateral accelerated endothelial cell
loss.
 It is more common in women
 and is associated with aslightly
increased prevalence of open-angle
glaucoma.
 • Inheritance. Most are sporadic, with
occasional AD inheritance. Mutation in
COL8A2 has been identified in an early-
onset variant.
 Symptoms. Gradually worsening
blurring, particularly in the morning,
due to corneal oedema. Onset is usually
in middle age or later.

60. Stage 1 Cornea guttata starts centrally and
spreads peripherally
Stage 2 Endothelial decompensation and stromal
edema
Stage 3 1. Corneal endothelium has a beaten
metal-like appearance with or without pigment
dusting
2. Descemet membrane is thickened.
3. Stromal edema may progress to involve
the epithelium causing intraepithelial and
interepithelial edema (epithelial bullae); bullous
keratopathy
Stage 4 Subepithelial fibrosis, scarring
SIGNS
Descemet's membrane becomes two to three times thicker
hematoxylin and eosin and PAS stains demonstrate well the
mushroom-shaped hemispherical or flat-topped anvil-like profiles of
the guttate bodies

62.  Treatment
1.Conservative options include topical sodium chloride
5% drops or ointment, reduction of intraocular
pressure and using a hair dryer to speed corneal
dehydration in the morning
2.Ruptured bullae can be made more comfortable by
the use of bandage contact lenses, cycloplegia,
antibiotic ointment and lubricants. Anterior stromal
puncture may be helpful.
3. Posterior lamellar (e.g. Descemet membrane-
stripping endothelial keratoplasty – DSAEK – or
Descemet membrane endothelial keratoplasty –
DMEK) and penetrating keratoplasty have a high
success rate.

63. 4.Options in eyes with poor visual potential
include conjunctival flaps and amniotic
membrane transplantation.
 A promising new treatment, topical Rho-kinase
inhibitor with prior transcorneal endothelial
cryotherapy, seems to stimulate endothelial cell
proliferation and improve function.
 Cataract surgery may worsen the corneal status
via significant endothelial cell loss, and
protective steps should be taken. A ‘triple
procedure’ (combined cataract surgery, lens
implantation and keratoplasty) may be
considered in eyes with corneal oedema.

64. •Harboyan syndrome, :-CHED + progressive postlingual
sensorineural hearing loss
•Congenital hereditary endothelial dystrophy (CHED) is
a disease of the corneal endothelium that is
characterized by bilateral, symmetric stromal haze,
which is apparent at or soon after birth.
•Diffuse opacification is secondary to edema caused by
abnormal endothelial development.CHED may be
inherited in an autosomal dominant (CHED1) or
autosomal recessive (CHED2) pattern.

65.  The autosomal dominant form of CHED
(CHED1) is slowly progressive and associated
with significant vision loss usually requiring
treatment with penetrating keratoplasty. The
gene hat causes CHED1 has been mapped to
a chromosome 20 locus
 Autosomal recessive form
• mutations in one of the genes in this locus,
the sodium borate transporter (SLC4A11), are
a likely cause of CHED2. SLC4A11 is
• expressed in human corneal endothelium
• But some cases may be caused by different
genes also
 histology

66. • Closer examination reveals the
texture of the epithelial surface to be
irregular, with a diffuse pigskin-like
roughness.
• Occasionally, discrete white dots also
may be seen in the stroma.
• In areas where stromal opacification is
less dense, Descemet’s membrane
appears gray,
• specular reflection may have a peau
d’orange texture.
• The endothelial layer may or may not
be visualized.
• A fine corneal pannus may be seen,as
well as low-grade inflammation.

67.  Treatment by Lamellar or penetrating
keratoplasty has a reasonable chance of success
when performed early but is risky & more
difficult than in adults.
 Undue delay carries risk of dense amblyopia
• D/DCongenital glaucoma
• Birth trauma
• Rubella keratitis
• Sclerocornea
• mucopolysaccharidoses

68. •Congenital corneal haze
•Moon crater like endothelial
change
•LM – scarce endothelial cell
•Confocal _ degenerative
endothelial cell
•Congenital bilateral diffuse hazelike ground glass or milky corneal
clouding characterizes patients with XECD. The endothelium has
indentations or ‘moon craters’ with missing endothelial cells.
•There are secondary epithelial changes of band keratopathy.
•The inheritance pattern is X-linked dominant and a gene that
causes XECD has been mapped to chromosome Xq25 however, no
causative gene has been identified.

69. types of dystrophies affecting vision
i. Macular dystrophy
ii. Lattice dystrophy
iii. Central crystalline
iv. Congenital hereditary endothelial dystrophy
v. Fuch’s dystrophy
types of dystrophies not affecting vision
i. Granular
ii. Fleck dystrophy.