This document discusses various types of corneal dystrophies presented by Dr. Puneet Sharma. It defines corneal dystrophies as a group of progressive, genetically determined disorders that cause non-inflammatory opacification of the cornea. It then describes several specific corneal dystrophies categorized by the layer of the cornea they affect (epithelial, stromal, endothelial). For each dystrophy, it covers inheritance pattern, histology, onset, signs/symptoms, and treatment. The document provides detailed information on Cogan dystrophy, Meesmann dystrophy, Reis-Bucklers dystrophy, granular dystrophy types 1 and 2, lattice dystrophy types 1 and 2, and Fuchs endothelial

1. Presenter- Dr.Puneet Sharma

2.  Corneal dystrophies are group of progressive,
usually bilateral, mostly genetically
determined, non-inflammatory opacifying
disorders.

3.  Epithelial
 Bowman layer
 Stromal
 Endothelial

4. Corneal dystrophies
 They are usually inherited.
 They affect the right and left eyes equally.
 They are not caused by other factors, such as
injury or diet.
 Most progress gradually.
 Usually begin in one of the five corneal layers
and may later spread to nearby layers.
 Most do not affect other parts of the body,
nor are they related to diseases affecting
other parts of the eye or body.
 Most can occur in healthy individual

5. Cogan epithelial basement membrane dystrophy
Inheritance- sporadic & rarely AD with incomplete
penetrance
Histology- thickening of basement membrane with
deposition of fibrillary protein b/w basement
membrane & bowman’s layer. Absence of
hemidesmosomes of basal epithelial cells which
is responsible for recurrent corneal erosions.

7. Onset 2nd decade. 10% of pts develop recurrent corneal
erosions in 3rd decade & others remain asymptomatic
throughout life.
Signs-
Dot like opacities
Epithelial microcysts
Subepithelial map-like patterns surrounded by a faint
haze
Whorled fingerprint - like lines
Similar features can be seen in an eye suffering
recurrent erosions from any cause

9.  Very rare, non-progressive abnormality of
corneal epithelial metabolism, underlying
which mutations in the gene encoding
corneal epithelial keratins have been
reported.
Inheritance is AD
Histology- irregular thickening of the epithelial
basement membrane & intraepithelial cysts

11. Symptoms are variable. Pts may be
asymptomatic or ocular irritation may begin
in the first few mnths of life.
Signs
 Myraid tiny intraepithelial cysts of uniform
size but variable density are maximal
centrally & extend towards but do not reach
the limbus
 Cornea may be slightly thinned & sensation
reduced.
Treatment- lubricants

13. Previously thought to be a variant of
meesmann, now believed to be genetically
distinct.
Inheritance is AD or X- linked dominant with
gene locus on Xp22.3 in the later in at least
some patients.
Signs
 Grey bands with a whorled configuration
 Retroillumination shows densely packed
microcysts

15.  Reis- Bucklers dystrophy categorized as
form of granular stromal dystrophy
Inheritance is AD with gene locus on 5q31
(gene TGFB1)
Histology shows replacement of Bowman layer
& epithelial basement membrane with fibrous
tissue

17. Onset is in 1st or 2nd decade with severe
recurrent corneal erosions.
Signs
 Grey-white, fine, round & polygonal
subepithelial opacities similar to those of
granular dystrophy type 1, most dense
centrally.
 Changes increase in density with age
resulting in a reticular pattern due to the
laying down of irregular bands of collagen
replacing Bowman layer.

19.  Corneal sensation is reduced & visual
impairment may occur due to scarring at level
of Bowman layer.
 Treatment is directed at recurrent erosions.
Excimer laser Keratectomy achieves
satisfactory control in some pts.

20. Inheritance is AD with gene locus on 10q24 &
5q31(geneTGFB1)
Histology shows curly fibres in Bowman layer
on electron microscopy
Onset is at end of 1st decade with recurrent
erosions

21. Signs subepithelial opacities in a honeycomb
morphology involving central cornea
Treatment not required as visual impairment is
less than Reiss- Bucklers dystrophy

23. Disorder of corneal lipid metabolism
associated with raised serum cholesterol in
approx 50% pts
Inheritance is AD with gene locus at 1q36

24. Signs
 Central, oval, subepithelial crystalline opacity
 Diffuse corneal haze & prominent corneal
arcus develop by 3rd decade
Treatment by excimer laser Keratectomy

26. Lattice corneal dystrophy
 Inheritance is AD with locus at 5q31 (gene
TGFB1)
 Histology shows amyloid, staining with congo
red & exhibiting characteristic green
birefringence when viewed with a polarizing
filter

27. Onset is at end of 1st decade with recurrent
erosions which precede typical stromal
changes
Signs
 Anterior stromal, glassy, refractile dots
 Coalescence into fine lattice lines, best seen
on retroillumination
 Deep & outward spread sparing the periphery

29.  Generalized stromal haze that progressively
impairs vision & may obscure some of the
lattice lines
 Corneal sensation is reduced
 Treatment by penetrating or deep lamellar
keratoplasty is frequently required.
Recurrence in graft may occur.

30. Inheritance is AD with a gene locus at 9q34
Histology shows amyloid deposits in corneal
stroma & other involved sites

32. Onset in 2nd decade, erosions are rare
Signs
 Randomly scattered, short, fine lattice lines
which are sparse, more delicate, more rapidly
oriented & more peripherally located than in
LCD1
 Corneal sensation is impaired

33. Treatment by keratoplasty may rarely be
required in later life to improve vision
Systemic features
 Progressive bilateral cranial & peripheral
neuropathy
 Dysarthria
 Mask like facial expression due to bilateral
facial palsy
 Protruding lips & pendulous ears
 Dry & extremely lax itchy skin

34.  Thick rope like bands of deposited amyloid
 Age of onset is late 70-90 yrs
 Inhertance AD (gene TGFB1)

36. Rare disorder mainly affecting japanese
patients
Inheritance is AR with gene locus at 1q32

37. Histology shows subepithelial & anterior
stromal accumulation of amyloid
Onset is within 1st & 2nd decades with severe
photophobia, watering & visual impairement

39. Signs
 Grey subepithelial nodules
 Gradual confluence, stromal involvement &
increase in size giving rise to a mulberry like
appearance
Treatment is with repeated superficial
keratectomy because of early recurrences on
corneal grafts

41. Inheritance is AD with gene locus at 5q31
Histology shows amorphous hyaline deposits
which stain bright red with masson trichrome
Onset is in 1st decade but vision is usually not
affected in early stage of disease

42. Signs
 Small, white, sharply demarcated deposits
resembling crumbs, sugar granules, rings or
snowflakes in central anterior stroma
 Overall pattern of deposition is radial or disc
shaped or may be in the form of a christmas
tree
 Initially the stroma b/w the opacities is clear

44.  Gradual increase in number & size of deposits
with deeper & outward spread but not
reaching the limbus
 Gradual confluence & diffuse haze of
intervening stroma causes visual impairement
 Corneal sensation is impaired
Treatment by penetrating or deep lamellar
keratopasty is usually required by 5th decade.
Superficial recurrences may require repeated
excimer laser keratectomy

45. Inheritance is AD with gene locus at 5q31
(gene TGFB1)
Histology shows both hyaline & amyloid in
stroma that stains with Masson trichrome &
congo red
Onset is in 2nd decade. Reccurent erosions are
rare & if present, mild

46. Signs
 Superficial, fine, opacities that resemble
rings, discs, stars or snowflakes, most
centrally resembling those in granular
dystrophy type 1 associated with deeper
linear opacities reminiscent of lattice
dystrophy
Treatment not required

48.  Least common stromal dystrophy in which a
systemic inborn error of keratin sulphate
metabolism seems to have only corneal
manifestations
 Divided in type 1, 1A & 2 depending on the
presence or absence of antigenic keratan
sulphate in the serum & cornea, these have
been shown to be due to mutations in same
sulphotransferase gene (CHST6)

49. Inheritance is AR with gene locus at 16q22
Histology shows abnormally close packing at
collagen in corneal lamellae & abnormal
aggregations of GAG which stain with
prussian blue & colloidal iron
Onset is toward end of 1st decade with visual
deterioration

50. Signs
 Anterior stromal haze involving central
cornea
 Greyish- white, dense, focal, poorly
delineated spots in anterior stroma centrally
& posterior stroma in the periphery
 Superficial deposits may produce an
irregularity of the corneal surface, although
recurrent erosions are unusual

52.  Increase in size & stromal haze
 Increasing opacification with eventual
involvement of full-thickness stroma up to
the limbus, associated with corneal thinning
Treatment by penetrating keratoplasty is
successful but late recurrences on the graft
may occur

53. Inheritance is AD
Signs
 Polygonal, cloudy grey opacities separated by
relatively clear spaces, in the posterior
stroma most prominent centrally, creating a
leather-like appearance
 The signs are similar to posterior crocodile
shagreen but it is differentiated by its central,
posterior location & mode of inheritance
Treatment not required

54. Fuchs endothelial dystrophy
 Bilateral accelerated endothelial cell loss
 More common in women
 Associated with slight increased prevalence of
open angle glaucoma

55. Inheritance AD although majority are sporadic
Onset slowly progressive disease is commonly
in old age, although earlier onset can occur
Signs
 Cornea guttata refers to irregular warts or
excrescences of Descemet membrane
secreted by abnormal endothelial cells

56.  Specular reflection shows tiny dark spots caused
by disruption of regular endothelial mosaic
 Progression occurs to a beaten metal appearance
which may be associated with melanin deposition
 Endothelial decompensation gradually leads to
central stromal oedema & blurred vision, worse
in the morning & clearing later in the day

58.  Epithelial oedema develops when stromal
thickening has increased by about 30%
 Persistent epithelial oedema results in the
formation of microcysts & bullae (bullous
keratopathy) which causes pain & discomfort
on rupture, thought to be due to exposure of
naked nerve endings

59. Treatment
 Topical sodium chloride 5% drops or
ointment, reduction in IOP
 Bandage contact lens
 Penetrating or deep lamellar keratoplasty
 Other options- conjunctival flaps & amniotic
membrane transplants
 Cataract surgery may accelerate endothelial
cell loss, a triple procedure (cataract surgery,
lens implantation & keratoplasty) may be
considered in eyes with corneal epithelial
oedema .

60.  Rare, innocuous & asymptomatic condition in
which corneal endothelial cells display
characteristics similar to epithelium.
Inheritance AD
Onset is at birth or soon thereafter, although it
is most frequently identified by chance in
later life

61. Signs
 Subtle vesicular endothelial lesions that may
become confluent band-like lesions or
diffuse opacities which may be asymmetrical
Ocular associations
 Iris abnormalities
 Glaucoma
 Alport syndrome
Treatment not required

63.  Rare dystrophy in which there is focal or
generalized absence of corneal endothelium
 2 main forms CHED1 & CHED2, later being
more severe
Inheritance
CHED1 is AD with the gene locus on 20p11.2-
q11.2.
CHED2 is AR with the gene locus on 20p13

64. Onset is perinatal
Signs
 Bilateral, symmetrical, diffuse corneal
oedema resulting in a blue-grey, ground-
glass appearance to total opacification
 Visual impairment is variable & visual acuity
may surpass than expected from corneal
appearance

66. Treatment by 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/D
 Congenital glaucoma
 Birth trauma
 Rubella keratitis
 Sclerocornea
 mucopolysaccharidoses