Corneal degeneration refers to conditions where the normal corneal cells undergo degenerative changes due to age or pathology. There are many types of corneal degeneration classified based on etiology and location. Common types include arcus senilis, band keratopathy, lipid depositions, crocodile shagreen, and Terrien's marginal degeneration. Corneal degenerations can cause visual symptoms but often do not require treatment for mild cases. Severe degenerations may be treated with procedures like excimer laser, lamellar keratoplasty, or penetrating keratoplasty to improve vision or relieve discomfort.

1. DR. ARNAV SINGH SAROYA

2. CORNEAL DEGENERATION
Corneal degenerations refers to the conditions in which
the normal cells undergo degenerative changes under the
influence of age or some pathologic conditions.
• Non-familial, late onset
•Asymmetric, unilateral, central or peripheral
•Changes to the tissue caused by inflammation, age, or
systemic disease.
•Characterized by a deposition of material, a thinning of
tissue, or vascularization

3. DIFFERENCE BETWEEN
DYSTROPHY DEGENERATION
• Age Early Late
• Heredity AD/AR None
• Laterality B/L U/L(B/L)
• Location Central Peripheral
• Corneal layers Discrete Not discrete
• Systemic diseases no common
• Characteristic Well defined Poorly defined
• Vascularity avascular correspond with vascularity

4. CLASSIFICATION
•1.Depending upon etiology
•INVOLUTIONAL NON-
(age related) INVOLUTIONAL (pathological)
1.Arcus senilis 1. Band keratopathy
2.Limbal girdle of Vogt 2. Amyloid degeneration
3.Crocodile shagreen 3. Lipid degeneration
4.Cornea Farinata 4. Salzmann's nodular
5.Hassal – Henle bodies 5. Terrien’s marginal
6.Furrow degeneration 6. Spheroidal

5. 2. Depending upon location
I. Axial Corneal Degenerations
a) Fatty Degenerations
b)Hyaline Degenerations
c) Amyloidosis
d)Calcific Degenerations (Band Keratopathy)
e)Salzmann’s Nodular Degeneration

6. •II. Peripheral Degenerations
a) Arcus Senilis
b) Vogt’s White Limbal Girdle
c) Hassall – Henle Bodies
d) Terriens’s Marginal Degeneration
e) Mooren’s Ulcer
f) Pellucid Marginal Degeneration
g) Furrow Degeneration (Senile Marginal
Degeneration)

7. ARCUS SENILIS & ARCUS JUVENILIS
Gerontoxon in the aged & Anterior Embryotoxon in the young.
Area : Peripheral cornea (starts inferiorly and progress superiorly to encircle
entire circumference)
Pathology : Lipid deposition
Prevalence
Increases with age
Men > Women
Age: >40yrs
Blacks affected at a younger age than Whites

8. Arcus senilis
• Innocuous and extremely common in elderly
• Occasionally associated with hyperlipoproteinaemia
• Bilateral, circumferential bands
of lipid deposits
• Diffuse central and sharp
peripheral border
• Peripheral border separated
from limbus by clear zone
• Clear zone may be thinned
( senile furrow)

9. Slit lamp examination:
• Best in Sclerotic scatter or Broad tangential view.
• Sharp peripheral border – ending at the edge of Bowman’s
layer with a lucent zone to the limbus.
• Diffuse central edge.
• Lipid deposition in the stroma – near Bowman’s layer > the
Descemet's membrane –.

10. Clear zone (furrow in slit beam)
Arcus
senilis

11. Histochemical
• Cholesterol, Cholesterol esters, phospholipids, neutral
Glycerides.
• Experimental studies: Vascular origin – in the form of low
density lipoproteins (LDL) cross the capillary wall.
• Bilateral symmetric & progresses slowly
• Lucid interval – due to vessel’s ability to reabsorb the lipid in
this area/ descemet's ends here.
• Stains for lipids- Oil red O & Sudan black.

12. Histopathology
• Has an hourglass appearance
• lipid is extracellular .
• advanced stages – involves
stromal lamellae.

13. Significance :
• No visual problem hence no treatment required.
• <40yrs with arcus – risk of Coronary artery disease –
evaluated for Hyperlipoproteinemia
• Increased levels of beta lipoproteins rich in cholesterol.
• Diseases – Nephrotic syndrome, Hypothyroidism,
Obstructive jaundice, Diabetic ketoacidosis.
• Seen in Lecithin cholesterol acyltransferase (LCAT) deficiency

14. Differential diagnosis
• Peripheral mosaic crocodile shagreen.
• Limbal girdle of Vogt.
• Residual scars from peripheral corneal hypersensitivity
(catarrhal) ulcer.

16. LIPID DEGENERATIONS
Primary :
• Rare – B/L, no disorders of lipid metabolism.
• Fatty acids – cholesterol, triglyceride, phospholipids
• Etiology – altered metabolic activity of
Keratocytes, increased vascular
permeability
• Clinical manifestation –
cosmetic or decrease vision.

17. LIPID DEGENERATIONS
Secondary lipid degeneration:
Located in superficial and deep stroma at areas of
vascularization.
Common – vascularised cornea – MC associated with HERPES
SIMPLEX AND HERPES ZOSTER, Interstitial keratitis, trauma,
corneal hydrops, corneal ulcers.
• Etiopathogenesis – increased permeability of vessels – or
decreased ability to remove lipid.
• Onset sudden – rapid decrease in vision.

18. Secondary lipid degeneration:
• Shape :
1.Sea fan with feathery edges – areas of inactive
neovascularization
2.Discoid lesion – active neovascularization

19. Lipid keratopathy
• Usually unilateral stromal deposits
without vascularization
• Rare, occurs spontaneously in
avascular cornea
• Unilateral stromal deposits with
vascularization
• Common, secondary to previous
disciform keratitis
Treatment - coagulation of feeder
vessels and/or keratoplasty
Treatment - keratoplasty, if severe
Primary Secondary

22. Secondary lipid degeneration

23. TREATMENT
1.Medical control of inflammatory disease.
2. Argon laser photocoagulation-feeder vessels.
3. Needle point cautery-feeder vessels.
4. Keratoplasty
5.Lipid might resolve with Subconjunctival Bevacizumab.

24. Band Shaped Keratopathy
TYPES : Calcific and Non – calcific forms
Clinically : begins at the periphery – 3 & 9 o’clock
• May also begin centrally
• Typical peripheral form – sharply demarcated peripheral
edge – separated from limbus by lucent zone.
• Small holes in the deposit represent areas where the corneal
nerves penetrate Bowman’s MEMBRANE.

26. •Early – opacity gray – becomes white & chalky – lucent
holes – penetrating corneal nerves.
•Lesion subepithelial –
Histopathology
•Fine basophilic granules –
Bowman’s layer.
Granules coalesce.
•Hyaline – like material – deposited in subepithelial
tissue( reduplication of Bowman’s layer)

27. • Calcific-Hydroxyapatite deposits of calcium in epithelium, Bowman`s
layer, and superficial stroma.
• Non-Calcified-Depositions of Urates- Brown colored.
• Can develop in glaucoma patients who use medications with
phenylmercuric nitrate or mercury.

28. • Fibrous pannus –
associated with calcification
• Overlying epithelium
atrophic
• Intracellular calcium
deposits.
• Extracellular only with local
disease or renal failure.

29. Physiology:
•Alteration of corneal metabolism – increased tissue
pH – precipitation of calcium, evaporation of tears –
carbon dioxide release – rise in pH.
Evaluation:
•History – medical workup – ocular examination
Signs & symptoms:
•Decrease vision ,foreign body sensation ,
photophobia, tearing

31. BAND KERATOPATHY (ADVANCED)

32. TREATMENT
If vision affected or eye uncomfortable-
• A) Chelation.
-Forceps, diamond burr
-No. 15 blade, spatula
-EDTA- 0.5-1.5%
• B) Excimer laser keratectomy.
• C) BCL, NSAIDS, antibiotic, steroids

33. LIMBAL GIRDLE OF VOGT
Girdle - crescentic yellow – white band – interpalpebral
limbus.
• B/L ,Symmetric , subepithelial ? STROMAL
• Nasal limbus > Temporal > inferior
Two types :
Type I – white band with holes “Swiss cheese pattern” –
central border sharp – represents early calcific band
keratopathy- lucent zone
Type II – true limbal girdle – chalky band without holes.

36. LIMBAL GIRDLE OF VOGT
•Incidence increases with age
> 20yrs
•Histopathology :lesion subepithelial
- overlying epithelial atrophy
- destruction & calcification of
Bowman
- Elastoid degeneration
•No treatment is required

37. CROCODILE SHAGREEN
• Usually bilateral
• Polygonal stromal opacities separated by
clear space
• Most frequently involve anterior stroma
(anterior crocodile shagreen)
• Occasionally involve posterior stroma
(posterior crocodile shagreen)

38. CROCODILE SHAGREEN
(Mosaic Keratopathy)
• Anterior Crocodile Shagreen-
 B/L symmetrical, asymptomatic.
 Level of Bowman's layer.
 Pattern-way stromal collagen fibrils inserts into
Bowman's layer OR breaks in bowman after trauma.
 Senile change, keratoconus+ hard contact lens, trauma,
BSK, hypotony

39. CROCODILE SHAGREEN
•Posterior crocodile shagreen-
• In central posterior stroma.
• B/L, does not disrupt descemet or endothelium,
asymptomatic.
• Histologically- irregular alignment of stromal lamellae with
a “Saw-Tooth Pattern
• Age related only
• Should be distinguished from central cloudy dystrophy of
Francois.

41. Crocodile shagreen-Mosaic pattern

42. CORNEA FARINATA
• Asymptomatic
• Tiny opacities
• Bilateral in deep corneal stroma.
• Flour – dust appearance, gray brown to white
• Histopathology – vacuoles filled with lipofuscin like substance

43. Corneal farinata- Flour like opacities

44. SPHEROIDAL DEGENERATION
•Corneal elastosis,Labrador keratopathy, Climatic droplet
keratopathy, Bietti nodular dystrophy, Fisherman’s
keratitis, chronic actinic keratopathy, Keratinoid
degeneration , Proteinaceous degeneration.
Classification:
• Type I (primary) : bilateral without ocular pathology
•Type II(secondary) : in association with ocular pathology

45. Clinically :
•Located in the anterior stroma ,replacing Bowman’s
layer.
•Clear to yellow gold spherules – sub epithelium within
Bowman’s or in superficial corneal stroma.
•Size : 0.1mm to 0.4mm
•Early stages – interpalpebral zone – 3 and 9 o’clock
•Progression – tend to darken with age – light yellow to
brownish yellow.

46. Etiologic factors:
•Ultraviolet radiation
•Micro trauma – sand, wind, dust, drying.
Incidence: Men > Women

48. Clinical system for grading
• Grade I : involvement of medial and lateral interpalpebral
strips.
• Grade II : central cornea affected – no visual problems.
• Grade III : central cornea affected with reduced vision.
• Grade IV : elevated nodules present with gr-III findings.

52. Deposits located superficial and deep to Bowman's
layer & in anterior stroma

53. Source of degenerative material
•Primary degeneration shows irregular
collagen from abnormal fibroblasts.
• Secondary degeneration shows protein
deposits from interaction of UV light
and plasma proteins.

54. Signs & symptoms
•Progressive – as long as exposed to causative
factors
•Initially asymptomatic – advanced stages – visual
deterioration.
•Advanced lesions – nodular – break through the
epithelium – foreign body sensation & irritation.

55. TREATMENT
a) Protection against UV damage-sunglasses.
b) Superficial keratectomy-improve vision.
c) Lamellar keratoplasty.

56. Salzmann Nodular Degeneration
•Degenerative process that follows episodes of
keratitis.
•Commonly associated – Phytencular disease, vernal
keratoconjunctivitis, trachoma, measles, scarlet
fever, interstitial keratitis, Thygeson`s superficial
punctate keratitis.
•Bilateral or may present unilateral.
•Commonly associated with meibomian gland
dysfunction.

57. Classification
1. Asymptomatic – isolated paracentral or
peripheral lesions.
2. Symptomatic – with irritation and foreign body
sensation.
3. Nodules – overlying the pupil, with reduction of
visual acuity.

58. Clinical examination
• Women > men
• Grayish-white to blue nodular lesions, 0.5-2mm
diameter.
• Nodules annular in location – mid periphery.
• Adjacent to corneal scarring or pannus, epithelial iron
line may outline the base of lesion.
• Progression is slow, Not Vascularized.

60. Histopathological:
• Dense collagen plaques with hyalinization – between
epithelium and Bowman’s layer.
• Bowman’s- absent, epithelium- atrophic
C/F:
• Generally asymptomatic
• Epithelial erosions- lacrimation, photophobia, irritation
Treatment:
• Lubrication and control of cause
• Superficial nodules – Excimer laser .
• Nodule in visual axis – decreased vision – Superficial
keratectomy, Penetrating keratectomy
• Surface flattened with diamond burr
• Mitomycin C

61. Salzmann nodular degeneration

62. AMYLOID DEGENERATION
• Group of proteins with starch like staining characteristics
• Amorphous extracellular substance- stains with Congo red and
thioflavin T.
• β-pleated sheet configuration of the protein organized into fibrils

63. Polymorphic Amyloid Degeneration
•After age 50
•Polymorphic punctate or filamentous opacities in
the central cornea
•Throughout the stroma( typically posterior)
•Gray on direct illumination
•Retroillumination- clear and crystalline
•Bilaterally and asymptomatic

64. AMYLOID

65. FURROW DEGENERATION
• Thinning can develop in the lucid interval between an
arcus & the limbus
• Noninflammatory
• Asymptomatic
• Intact epithelium

67. TERRIEN’S MARGINAL CORNEAL
DEGENERATION
• Peripheral inflammatory/non-inflammatory thinning of
cornea.
• Rare disorder – unknown etiology.
• Seen at any age – most common between 20 – 40 yrs.
• Men > Women : 3:1
• Bilateral & Symmetric

68. Clinical examination
• Begins superonasally – fine punctate opacities – anterior
stroma
• Fine superficial vascularization – leading to the lesion
• Stroma progressively thins
• Gutter formation between opacity and limbus.
• Peripheral edge slopes – central steeper.
• Degeneration due to excess Lipid deposition at advancing
edge or the inability to metabolize lipids.

70. Types:
Quiescent type : common – older patients –
asymptomatic – produces no pain.
Inflammatory type : younger : recurrent episodes of
inflammation, episcleritis, scleritis resembles Fuch’s
superficial marginal keratitis
Histopathology:
•Fibrillar degeneration of collagen
•Fibrous tissue seen
•Cholesterol crystal deposition
•Sparse inflammatory cells
• Bowman’s- fragmented/ absent
• Epithelium- intact

71. Course of disease:
• Can progress to high against-the-rule or oblique astigmatism.
• Disease progression is slow.
• Visual deterioration d/t increasing corneal astigmatism.
• Perforation may occur spontaneously or secondary to minor
trauma.
• Pseudopterygium may develop in long standing cases.

72. TREATMENT:
• Astigmatism- Gas permeable Scleral contact lenses.
• lamellar or eccentric penetrating grafts.
• Crescent shaped excision of gutter with suturing of the
healthier margins if possible-results are unsatisfactory.

74. • Peripheral corneal thinning in terrian
• marginal degeneration
• Pseudopterygium in
• Terrian marginal degeneration

75. PELLUCID MARGINAL DEGENERATION
• uncommon form of corneal thinning and ectasia
• Seen in inferior cornea – between 4 – 8o’clock
• Stroma – clear, epithelized, nonvascularized.
• Thinned Area 1 – 2mm.
• Age 20 – 40yrs.
• Maybe progressive.
• Hydrops and corneal scarring can develop.

76. • Histology : localized loss of Bowman’s layer.

78. TREATMENT:
a) Spectacles-Fails.
b) Gas permeable scleral contact lens.
c) Surgical:
1. Central lamellar keratoplasty.
2. Wedge resection of diseased tissue, large
penetrating keratoplasty, crescentic lamellar
keratoplasty, and thermokeratoplasty.

79. Coats White Ring
• A less than 1mm circle area of gray-
white dot in the superficial stroma.
• The ring stains for iron
• Is an iron deposit of fibrotic remnants
of a metallic foreign body.
• Prevention and treatment –
The lesions do not progress unless
there is associated inflammation.
Patients should not be treated with
steroids and anti inflammatory
medication.

80. Peripheral cornea guttae
• Hassall-Henle bodies
• Small, wartlike excrescences
• Peripheral portion of Descemet's membrane
• Small, dark dimples within the endothelial
mosaic
• localized overproduction of basement
membrane by endothelial cells

81. Metabolic disorders
Systemic
consultatio
n
1. Cystinosis (AR, cysteine deposition,
pediatric renal failure)
2. Mucopolysacharidosis MPS (GAG,
pigmentary retinopathy, optic atrophy, facial
coarseness, cardiac, skeletal)
3. Wilson (copper, deccease cerruloplasmin, kayser
fleischer ring, sunflower cat, liver basal ganglia,
Gonio, penecillamine)
4. Fabry (X linked, decrease alpha galactosidase,
vortex keratopathy, spoke shaped post cat,

83. IRON LINES