1. The document discusses various types of corneal infections including bacterial keratitis, acanthamoeba keratitis, fungal keratitis, herpes simplex keratitis, and herpes zoster ophthalmicus. 2. It describes the etiology, symptoms, signs, investigations, and treatment for each type of infection. 3. Key diagnostic tests and treatments include corneal scrapings and cultures, topical and oral antivirals and antibiotics, tear substitutes, and cycloplegics depending on the infective organism involved.

1. Mohamed Abdelzaher MD,
FRCS
corne
a

2. The transparent anterior 1/6th of the outer coat of the eye
Limbus is the junction between cornea & sclera
Limbus

3. • Measured by corneal Caliber or
Pentacam corneal topography
• Important in Congenital
Glaucoma

4. • Measured by corneal
pachymetry
• Important in corneal refractive
surgery & IOP measurement

5. Keratometry

7. • Measured by Pentacam corneal
topography
• Important in Keratoconus

8. KeratoconusLarger radius
Flatter surface
Smaller radius
Steeper surface

9. Pentacam

10. • Anterior Epithelium
• Bowman Layer
• Corneal Stroma
• Descemet membrane
• Endothelium

11. • Stratified Squamous Non
Keratinised
1. Superficial flat
2. Middle Polhydral
3. Deep Columnar
• Superficial cells are
continuously desquamated
• Regeneration occurs from
limbal stem cells

12. • Condensation of collagen fibres
• Tough layer
• Cannot regenerate

13. • 90% of corneal
thickness
• Collagen +
Keratocytes
• Collagen is
arranged in criss-
cross pattern

14. • Formed of:
a. Anterior banded zone: fetal,
cannot regenerate
b. Posterior non banded zone:
gradually thickens with age,
can regenerate

15. • Single layer of cells
• Hexagonal in shape
• Examined by Specular microscopy
• Decrease in number with age
• Responsible for corneal deturgence
(Relative dryness)

16. • Anterior Epithelium: Continue with conjunctival
epithelium
• Bowman Layer: Terminates in rounded edge
• Corneal Stroma: Blends with scleral stroma
• Descemet membrane: Ends as Schawlbe’ line
• Endothelium: Continue with trabecular meshwork

17. • Cornea is the Transparent anterior 1/6th window
• Corneal Transparency is dependant on the following:
1. Active Deturgence: Endothelium pump
2. Regular orientation and spacing of stromal collagen fibres
3. Cornea is Avascular
4. Non myelinated corneal nerve fibres
5. Pre-corneal tear film fill the irregularities in corneal epithelium

18. Normal cornea
Regular spacing
No light scatter
Corneal edema
Irregular spacing
Light scatter

19. • Sources:
1. Tear Film
2. Aqueous humor
3. Limbal blood vessels
• V Nerve (ophthalmic division)

20. Corneal sensation
Handheld esthesiometer
The handheld esthesiometer is a device that contains a thin,
retractable, nylon monofilament that extends up to 6 cm in
length. Variable pressure can be applied by the device by the
adjusting the length. The monofilament ranges from 60 mm to
5 mm and as the length is decreased the pressure increases
from 11 mm/gm to 200 mm/gm.
Steps for using the handheld
esthesiometer:
1.Extend the filament to full length of 6 cm
2.Retract the filament incrementally in 0.5 cm
steps until the patient can feel its contact
3.Record the length (NOTE: The shorter the
length indicates decreased sensation.)
4.Compare the fellow cornea
5.Repeat steps 1-4 in each quadrant: superior,
temporal, inferior, nasal
6.Sterilize the filament and retract back into

22. • Bacterial
• Protozoal
• Viral
• Fungal

23. Definition
Acute Suppurative Inflammation of the cornea
Aetiology
- Corneal trauma: e.g. CL
- KCS
- Lagophthalmos
- Loss of sensation
- N. Gonorrhea
- N. Meningitidis
- C. Diphtheriae
- H. Influenza
- Droplet
- Contact
- Vit A deficiency
- Immunocompromised
- Cocci: pneumo, staph, strept
- Bacilli: pseudomonas
- Conjunctiva
- Lacrimal sac
- Lid margin

24. Pathology
• Entry & Adherence of
organism to breached
epithelium enters the
stroma
• PMNs & Lymphocytes
infiltrates stroma &
epithelium
• Infective organism multiplies,
release its toxins & enzymes

25. • Epithelium casts off giving
an ulcer with irregular edge
& necrotic floor
• Posterior abscess may form
causing Descematocele or
corneal perforation
• Diffusion of toxins causing
iridocyclitis

26. • All necrotic tissues cast off
giving a large clean ulcer
with Smooth & Sloping edge
and clean floor

27. • Epithelium: grows by mitosis
& sliding
• Bowman layer: does not
regenerate giving a scar
• Stroma:
❖ Keratocytes proliferate &
lay down fibrous tissue
❖ Vascularisation extends
from limbal vessels

28. Symptoms
Stitching
Referred to the eye brow
Because of:
• corneal edema
• accompanying iridocyclitis
Lacrimation

29. • These symptoms are due to exposure of the corneal nerve
endings

30. Signs Edema Ciliary injection
• Loss of luster
• Ulcer with necrotic tissue
• +ve flourescein stain
Activity
Hypopyon

31. Typical Atypical
Organism Pneumococci Other organisms
Site Central Anywhere
Character Serpiginous Spread in all directions
Perforation Common Rare
Descematocele Never +/-

32. Complications
• Due to diffusion of bacterial
toxins
• Anterior chamber activity
(cells & flare)
• +/- Hypopyon

33. Peripheral Anterior Synechia (PAS)
Plasmoid
Aqueous

34. • Bulging of Descemet’s
membrane
• C/P: transparent bulging
corneal vesicle
• It does not occur in children
(thin Descemet) & in
pneumococcal
infection(destruction of
Descemet)
• Fate:
1. Rupture: Perforated corneal ulcer
2. Cicatrisation

35. Complications

36. Weak thin corneal scar
Bulging of the cornea

39. Complications
• The iris adheres to the back of the cornea
• May cause 2ry angle closure Glaucoma

40. • Iris prolapses through sudden
large corneal perforation
• Fate:
1. Leucoma adherent
2. Corneal staphyloma

41. • Dense corneal opacity with iris
adherent to the back of the scar
• Irregular AC
• Irregular pupil
• Weak Ectatic corneal scar with iris
adherent to the back of the cornea
• Lost AC

44. Complications

45. Investigations
• Scrape the corneal ulcer edge & floor
• Perform scraping prior to topical antibiotics (24 hours) or fluorescein
drops
• Send Contact lens (if present) for microbiological assessment

46. Treatment
• Large (> 1.5 mm), Central Ulcer
• Severe infection: Hypopyon, Endophthalmitis
• Poor compliance
• Failure to improve

47. • Broad spectrum (e.g.
fluoquinolone: Gatifloxacin,
Moxifloxacin)
• Given hourly in the 1st 24 -
48 hours
• Indications:
1. Severe infection; hypopyon
2. Specific organism e.g Pseudomonas
• Vancomycin (Gm +ve)+ Ceftazidim (Gm -
ve)
• Given hourly in the 1st 24 - 48 hours

48. • Cyclopentolate E.D, Atropine E.D
• Relieve Ciliary body spasm (Cyclitis)
• Stabilize the blood aqueous barrier (Iritis)

49. • Tear Substitutes (Drops & Gel)
• Use preservative free drops
• Oral vitamin A

50. • Indications:
1. Limbal lesion
2. Corneal Perforation
• Oral Fluoroquinolone e.g Ciprofloxacin
• for severe pain

51. Aqueous supressants e.g. Timolol E.D
PTK, Keratoplasty
Keratoplasty
Keratoplasty
Intravitreal antibiotics +/- Vitrectomy

52. Definition
Acute Inflammation of the cornea caused by the protozoa Acanthamoeba
Aetiology
- Contact lens wear
especially
A. Extended wear
B. Poor hygiene e.g. cleaning
CL with tap water
C. Swimming pools
Acanthamoeba:
A free living protozoa
Isolated from soil,
dust, sea, chlorinated
water
- Poor CL hygiene

53. Symptoms
Severe
Stitching
Disproportionate to
often relatively mild
clinical findings
Because of:
• corneal edema
• accompanying iridocyclitis
Lacrimation

54. Signs

55. Investigations
• Scrape the corneal ulcer edge & floor
• Perform scraping prior to topical antibiotics or fluorescein drops
• Send Contact lens (if present) for microbiological assessment
• Stain: Gram, Giemsa, Calcofluor white
• Culture media: Non nutrient agar seeded with E.Coli

56. Treatment
• Anti-Acanthamoeba: Propamidine, Chlorhexidine
• Anti-biotics for bacterial co-infection
• Povidone iodine
• Anti-fungal: fluconazole, ketoconazole
• Tear substitutes to promote epithelialisation
• Analgesics for severe pain

57. Definition
Acute Inflammation of the cornea caused by Fungal infection
Aetiology
- Contact Lens
- Trauma with
organic material
- Corneal
trauma: especially
with organic matter
- Steroid abuse
- Immunocompromised
- In cold climates
- In warm climates

58. Symptoms
Less Severe
Stitching
Insidious onset
Because of:
• corneal edema
• accompanying iridocyclitis
Lacrimation

59. Signs

60. Investigations
• Scrape the corneal ulcer edge & floor +/- Corneal biopsy
• Perform scraping prior to topical antibiotics or fluorescein drops
• Send Contact lens (if present) for microbiological assessment
• Stain: Giemsa stain, Periodic Acid Schiff (PAS)
• Culture media: Sabouraud dextrose agar

61. Treatment
• Anti-Fungal: fluconazole, Itraconazole, Natamycin
• Anti-biotics for bacterial co-infection
• Tear substitutes to promote epithelialisation
• Anti-fungal: fluconazole, ketoconazole, Amphotericin B
• Analgesics for severe pain

62. Definition
Acute Inflammation of the cornea caused by Herpes Simplex virus
Aetiology
• 1ry infection is usually blepharo-
conjunctivitis, occasionally with
corneal involvement (Droplet).
• Following this, the virus ascends
the sensory nerve axon to reside
in latency in the trigeminal
ganglion.
• Viral reactivation, replication &
retrograde migration to the
cornea results in recurrent
keratitis
- Corneal
trauma: CL,
LASIK
- Steroid abuse
- Crowding
- Poor Hygiene
- Immunocompromised
- HSV 1: DNA virus
- HSV 2:rarely affect
the cornea
☠️

63. C/P
• Usually in childhood (not before 6th month age, because of maternal Ab)
• Transmitted by Droplet or rarely contact
• Usually pass sub clinically or cause mild FAHM, upper respiratory tract symptoms
‫دور‬‫برد‬
• Ocular: Blepharitis + Follicular Conjunctivitis

64. Symptoms
Less Severe
Discomfort !!!!
Because of:
• corneal edema
• accompanying iridocyclitis
Lacrimation

65. Signs

69. Investigations
• Usually not needed (a clinical diagnosis)
• Corneal & Conjunctival swab
• Culture + PCR + ELVIS (Enzyme Linked Viral Induced System)
• Stain: Giemsa stain (Multinuclear giant cells)
• Culture media: Cell culture

70. Treatment
• Anti-VIRAL:
A. Acyclovir 3% E.Oint 5 times daily for 14 days or stopped at least 3 days after
complete healing
B. Ganciclovir 0.15% E.Gel 5 times daily for 14 days or stopped at least 3 days after
complete healing
• Tear substitutes to promote epithelialisation
• Cycloplegic E.D
• Anti-biotics to guard against 2ry bacterial infection

71. • Due to virus replication within keratocytes or through immune-mediated reaction
• Rare & Difficult to diagnose
• May progress into Necrotizing Stromal keratitis +/- corneal perforation

72. Treatment
• Anti-VIRAL:
A. Acyclovir 3% E.Oint 5 times daily for 14 days or stopped at least 3 days after
complete healing
B. Ganciclovir 0.15% E.Gel 5 times daily for 14 days or stopped at least 3 days after
complete healing
• Steroids: Under umbrella of anti-viral, minimum dose, deferred till epithelium
heals
• Tear substitutes to promote epithelialisation
• Cycloplegic E.D
• Anti-biotics to guard against 2ry bacterial infection
• Anti-Viral: Acyclovir 400 gm five times daily

73. Due to virus replication within Endothelium or through immune-mediated reaction
• Disc shaped corneal edema
• KPs (Keratic precipitates)
• Wessely immune ring
Symptoms
Painless diminution of vision
Signs

75. Treatment
• Anti-VIRAL:
A. Acyclovir 3% E.Oint 5 times daily for 14 days or stopped at least 3 days after
complete healing
B. Ganciclovir 0.15% E.Gel 5 times daily for 14 days or stopped at least 3 days after
complete healing
• Steroids: Under umbrella of anti-viral, minimum dose, deferred till epithelium
heals
• Tear substitutes to promote epithelialisation
• Cycloplegic E.D
• Anti-biotics to guard against 2ry bacterial infection
• Anti-Viral: Acyclovir 400 gm five times daily

76. • Sterile ulcer (No virus activity)
• Caused by:
A. Toxicity to topical medications
B. Lack of neural derived growth factors
C. Poor tear surfacing
• Minimize topical drops
• Use preservative free drops
• Artificial tears
• Soft bandage contact lens
• Tarsorrhaphy
Treatment

77. Definition
Acute Inflammation of the eye caused by Varicella Zoster Virus (VZV)
Aetiology
• 1ry infection results in chicken
pox (Varicella). (Droplet,
Contact)
• Following this, the virus become
latent in the trigeminal ganglion.
• Viral reactivation, replication &
retrograde migration along
ophthalmic nerve to the eye
results in recurrent keratitis
- Corneal
trauma: CL,
LASIK
- Steroid abuse
- Crowding
- Poor Hygiene
- Immunocompromised
- VZV: DNA virus

78. • Viral prodrome: FAHM ‫جديري‬
• Pre-herpetic neuralgia: From tingling to severe electric pain
• Rash: Papules Vesicles Pustules Crusts (Do Not Cross the
Midline)
• Hutchinson’s sign: cutaneous involvement of tip or side of the nose, indicating
nasociliary involvement and likelihood of ocular complications

85. Treatment
• Anti-VIRAL:
A. Acyclovir 3% E.Oint 5 times daily for 14 days or stopped at least 3 days after complete healing
B. Ganciclovir 0.15% E.Gel 5 times daily for 14 days or stopped at least 3 days after complete healing
• Steroids: Under umbrella of anti-viral, minimum dose, deferred till epithelium heals
• Tear substitutes to promote epithelialisation
• Cycloplegic E.D
• Anti-biotics to guard against 2ry bacterial infection
• Anti-Viral: Acyclovir 800 gm five times daily
• Analgesics
• Steroids: inhibit development of post herpetic neuralgia
• Topical antibiotic-steroid + cool zinc calamine lotion

86. • Pain (Burning or Lancinating) along the course of the nerve lasting > one month
after healing of the rash
• More in old age
• May cause depression, even suicide
• amitriptyline
• gabapentin
• topical capsaicin cream
Treatment

87. Definition
Corneal Ulcer resistant for topical broad spectrum antibiotic therapy for 48 hours

88. • Resistant: MRSA
• New strains
• Fungi
• Acanthamoeba
• Viruses
• Dry eye
• Loss of sensation
• Exposure
• Wrong diagnosis
• Wrong treatment
• Decision directed
from previous
medications
• Non compliance
• immunosuppresse
d
• Collagen disorders
e.g Rheumatoid
• Over dose: toxicity
• Low dose: chronicity
• Steroids

89. Management
• Careful history taking:
❖ Contact lens hygiene
❖ trauma with organic mater
❖ Topical steroid abuse
❖ Systemic immunesuppression
• Investigate:
• Stop anti-infective therapy for 24 hours
• Scrape ulcer’s edge & floor
• Use special stains e.g. PAS, Calcofluor white
• Use special culture media e.g. Sabouraud agar, non nutrient agar
• Do PCR
• Search for characteristic signs:
❖ Ring infiltrate
❖ Heaped hypopyon
❖ Diminished corneal sensation

90. Perforated/Thinned Corneal Ulcer
Non Surgical Treatment Surgical Treatment
1)Anti-infectious agents: topical & systemic
2)Anti-glaucoma drugs
3)Anti-collagenases: acetyl cysteine,
tetracycline
4)Anti-inflammatory drugs: steroid sparing
5)Promote epithelial healing
1)Cyanoacrylate glue
2)Fibrin glue
3)Conjunctival flap
4)Amniotic membrane transplantation
5)Suture
6)Tectonic Keratoplasty

91. 1)Cyanoacrylate glue:
 Principle:
1.Bridging the corneal tissue gap  allow for re-epithelialization
2.Bacteriostatic effect
 Indications:
1. Corneal perforation:
< 2 mm
With small amount of tissue loss
Stellate wound with poor central apposition
Needing excessive sutures in visual axis
1. Corneal thinning, defects before perforation:
< 3 mm
Central, concave
Non-infected, progressive
 Fate:
1.Spontaneous dislodgement after re-
epithelialization
2.Removed gently after 6-8 weeks

92. 2)Fibrin glue:
 Advantages over cyanoacrylate:
1.solidify quickly
2.apply easily
3.cause less discomfort
 Disadvantages:
1.start to degrade much faster than cyanoacrylate,
2.have no bacteriostatic effects (like
cyanoacrylate)
3.risk of transmission of prion/viral diseases with
the use of bovine products in its constituents
3) Amniotic membrane
transplantation:
 Advantages:
1.Not invaded by blood vessels
2.↓ scar tissue proliferation
3.Does not trigger immune reaction
4.Stimulate re-epithelialization
5.Anti-inflammatory effects

93. 4) Conjunctival flap:
 Advantages:
1.Brings superficial blood
vessels to promote
healing of corneal ulcers
 preventing corneal
perforation.
2.Control pain
3.Eliminate the use of
frequent medications,
4.Provide an alternative to
invasive surgery.
 Contraindications:
1.Active suppurative
keratitis with marked
stromal thinning
2.Eyes with frank
perforation because the
leak will continue under
the flap

94.  Indications:
Large > 3 mm corneal
perforation
 Timing:
1.If the perforation could be sealed
temporarily with glue  delay
keratoplasty for 3-5 days to allow
sealing of the perforation &
restoration and stabilization of
the AC
2.If not  urgent keratoplasty
4) Tectonic Keratoplasty: