Cornea
Department of Ophthalmology
General Hospital
What is the cornea?
• The cornea is the eye's outermost layer. It is
the clear, dome-shaped surface that covers
the front of the eye.
Structure of the Cornea
• The corneal tissue is arranged in five basic
layers, each having an important function.
epithelium
Bowman’s layer
stroma
Descemet’s membrane
endothelium
What is the function of the
cornea?
1. shield the rest of the eye from germs, dust,
and other harmful matter
2. controls and focuses the entry of light into
the eye.
Characteristic
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Clear
Regular surface
Avascularity
Immune privilege
Normal Eye
keratopathy
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Anomaly
Infection
Dystropy and Degeneration
Injury
Autoimmune
Metabolic
Others
Congenital anomaly
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megalocornea 13mm
microcornea 9mm
cornea plana
keratoglobus
keratoconus
Microcornea
Microcorneaa
Cornea Plana
Keratoglobus
Keratoconus with corneal
scarring
Extreme Keratoconus
Pathogenesis of keratitis
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Bacteria
Virus
Fungus
Chlamydia
Acanthamoeba
Tubercle or Syphilis
keratitis
• Pathophisiology
corneal infiltration
corneal ulcer
corneal nebula
corneal leucoma
corneal perforation
Corneal fistula
Corneal staphyloma
Herpes Simplex Keratitis
（HSK）
• Pathogen： HSV－Ｉ HSV－II
• Typing： Dendritic Keratitis
Disciform Keratitis
Geographic Keratitis
Necrotizing stromal keratitis
Uveitis
Acute dendritic HSK
• Symptom: pain ,tearing, FB sensation,
redness, sensitivity to light,vision decrease
• Signs: tree-branching in staining
• Treatment: anti-viral drugs( topical)
cycloplegics
steroid is contraindicated
Herpes Keratitis
Necrotic stromal herpetic
keratitis
complications of HSV infection
• neurotrophic ulcer
• decreased visual acuity from scarring or
from irregular astigmatism
• lipid keratopathy
• corneal perforation or corneal scars
• if PKP needed, preferable to wait until
decrease in active inflammation
Other viral infection
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EKC
PCF
AHKC
Measles Keratitis
Rubella Keratitis
Mumps Keratitis
EKC
Rosacea Keratitis
Corneal ulcer
• Local necrosis of corneal tissue due to
invasion by bacteria, fungi,viruses, or
acanthamoeba
Bacteria corneal ulcer
• Staphylococcus, pseudomonas, treptococcus
• Followed by contact lens wear, corneal trauma or
a corneal foreign body
• Symptoms and signs--- pain , lacrimation,
photophobia
hyperemia, stroma edema, diffuse inflammation,
hypopyon,perforation, purulent conjunctivitis
Pseudomonas
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gram negative rod
frequent cause of bacterial keratitis
mostly associated with contact lens
rapid progression and perforation often
occurs in few days
• ulcer with surrounding stromal edema and
diffuse inflammation
Corneal Ulcer
Pneudomonas corneal ulcer
Therapy
corneal scraping for culture
intensive fortified antibiotics
gentamycin, vancomycin, oflaxin
Systemic therapy for peforation
Cycloplegics
Cold compress
Fungal keratitis
• Pathogen：fusarium , aspergillus,candida
• Ulcers: feathery border, satellite lesion , the
infiltrate extends beyond the epithelial
defect
• Therapy：natamycin, ketoconazole,
amphotericin, fluconazole
Acanthamoeba keratitis
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Contact lens use
Pain
Hallmark ring infiltrate
Often misdiagnosed
Drug :difficult , often fail, propamidine,
neomycin , antiseptic
Acanthamoeba Keratitis
Acanthamoeba Keratitis
Corneal degeneration
• Arcus senilis
• Deposition
• Ectasia：Terrien’s marginal degenaration，
keratoconus
• Others：Salzmann nodule
Band Keratopathy
Pellucid Marginal Corneal
Degeneration
Saltzmann Nodules
Terrien’s marginal degeneration
Corneal dystrophy
• Epithelium：Meesmann，map-dot-fingerprint
• Bowman’s：Reis-Buckler，anterior crocodile
shangreen
• stroma：granular，lattice，macular，gelatinous
droplike，central crystalline，fleck
• Endothelium：Fuchs，congenital hereditary
endothelial dystrophyCHED，posterior
polymorphous dystrophyPPMD
Granular corneal dsytrophy
Granular corneal dsytrophy
Macular degeneration
Map dot fingerprint corneal
dystrophy
Map dot fingerprint corneal
dystrophy
Lattice dystrophy
Fuch’s Dystrophy
Avellinodystrophy
Reis-Bukler
Corneal injury
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Mechanical：corneal abrasion
Contusion：
Chemical：alkali, acid
Burn
Radiation：
Chemical Burn
Serious Chemical Burns
Central Corneal Scarring
Corneal Vascularization
Corneal blood staining
Trachoma scarred
Immune-related
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atopic
Allergic
immunocomplex
Autoimmune
immunodeficiency
metabolic disease
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Amino acidopathy：cystinosis
mucopolysacharidosis
lipo：Fabry’
Wilson’s disease
others：DM, gout
Cystinosis
Fabray’s disease
Homocytinuria
Lipid keratopathy
K-F Ring
Epithelial
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Resistant corneal epithelial erosion
Superficial punctate keratitis
Filamentary keratitis
PCED
Bullous keratopathy（BK）
Bullous Keratopathy
Descemetocele
Peter’Anomaly
Posterior Embryotoxon
Axenfeld’s Anomaly
Axenfeld’s Anomaly
ICE Syndrome
Corneal tumor
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Dermoid cyst
Limbal papilloma
Bowen’s disease
squamous carcinoma, corneal sarcoma，
malignant melanoma
Systemic related
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Vitamin A dificiency
Steven-Johnson syndrome
Bechet syndrome
Reiter syndrome
Rosacea Keratitis
Ocular-cicatricial pemphigoid
Sarcoidosis
Grave’s Ophthalmopathy
Corneal transplantation
• A surgical procedure to remove the diseased
part of the cornea and replace it with a
similarly sized and shaped part of a healthy
donor cornea
keratoplasty
keratoplasty
Corneal vascularizaiton