1. 1.OUTER COAT 2.MIDDLE COAT 3.INNER COAT

2. Tough Fibrous Coat Post 5/6 th of Globe White & Opaque Sclera Radius---12mm

3. Tough Fibrous Coat Ant 1/6th of Globe Transparent Cornea Radius---8mm

4. Junction of Cornea and Sclera Contains 1.Trabecular Meshwork 2.Canal of Schlemn

5. Verticle-------10.6 mm Horizontal---11.7 mm Thickness Central portion----0.52 mm Peripheral portion----1 mm

6. Three Layers 1. Epithelium & its Basement 2. Stroma & its ant condensation ( Bowman Zone) 3.Endothelium & its Basement (Descemet Membrane)

7. From Anterior to Posterior 1. Epithelium 2. Bowman Zone 3. Stroma 4. Descemet Membrane 5. Endothelium

8. * 50-60 µm thick * Covers the stroma anteriorly * Continuous with epithelium of conjunctiva * Life of epithelial cells is 7 days * Prevent aqueous solutions to penetrate

9. * Surface cell layer * Wing cell layer * Basal cell layer * Basement membrane

10. 90% of the corneal thickness * Bowman Zone * Lamellar Stroma Once deformed its typical structure is not restored

11. * Descemet membrane (Regenerates) * Endothelium Single layer of cells Cells are tightly bound together Responsible for dehydration Never regenerates

12. * Central cornea is avascular * Corneoscleral limbus is generously supplied by anterior conjuntival branches of the anterior ciliary arteries * Aqueous humor and tear film provides nutrients

13. * Branches of the ophthalmic division of trigeminal nerve and are solely sensory * Most are concentrated in the anterior stroma beneath the Bowman zone and send branches forward into epithelium * Descemet membrane and endothelium are not innervated

14. * The microvilli of the anterior surface of the squamous cell layer are wet by the mucin of tear film * These cells are joined by tight junctions that exclude water soluble substances

15. * Tight junctions of the epithelial cells * Endothelial pump mechanism * Absence of blood vessels * Absence of pigments * Scarcity of cell nuclei in stroma * Regular structure of stroma

16. Superficial 1.Punctate epithelial erosions Tiny,slightly depressed, epithelial defects which stain with flourescein but not with rose Bengal PEE are non specific and may develop in a wide variety of keratopathies

17. Superficial 2.Punctate epithelial keratitis It is the hallmark of viral infections. * Swollen epithelial cells * Visible unstained * Stains with rose bengal

18. Superficial 3.Epithelial Oedema Sign of * Endothelial decompensation * Severe acute elevation of IOP

19. Superficial 4.Filaments Small coma shaped mucus strands lined with epithelium. One end attached with epithelium

20. Superficial 5.Pannus Inflammatory or degenerative ingrowth of fibro vascular tissue from limbus

21. Stromal Lesions 1.Infiltrates Focal areas of active stromal inflammation 2. Oedema Increased corneal thickness Decreased transparency 3. Vascularization

22. Lesions of Descemet Membrane 1. Breaks Corneal enlargement Keratoconus Birth trauma 2. Folds (Striate Keratopathy) Surgical trauma Ocular hypotony Stromal oedema

23. * Control of infection * Control of inflammation * Promotion of re-epithelialization – lubrication – lid closure – bandage soft contact lens * Prevention of perforation – tissue adhesive glue – conjunctival flap – systemic immunosuppressive agents * Corneal grafting

24. * Ocular surface disease: Trauma, post-herpetic corneal disease, bullous keratopathy, corneal exposure, dry eye and diminished corneal sensation. * Contact lens wear

25. Pathogens which can produce corneal infection in intact epithelium. * 1.Neisseria gonorrhoeae * 2.Corynebacterium diphtheriae * 3.Listeria * 4.Haemophilus

26. * Oval, yellow-white, densely opaque stromal suppuration surrounded by relatively clear cornea

29. * Thick mucopurulent exudate, diffuse liquefactive necrosis and semi-opaque ground glass appearance of adjacent stroma

30. * Shallow ulceration, grey-white pleomorphic suppuration and diffuse stromal opalescence. Endotoxins may induce ring-shaped corneal infilterates

31. * History * Clinical examination (including staining and sensitivity) * Hospitalization * Corneal scrapping * Treatment

32. * Topical antibiotics – combination therapy with fortified amino glycoside and fortified cephalosporin or monotherapy with fluoroquinolone. Initial instillation at hourly intervals. * Subconjunctival injections * Systemic ciprofloxacin 750mg BD

33. * Cycloplegics * Steroid therapy (controversial) * Corneal biopsy or excisional keratoplasty

34. * Wrong diagnosis * Wrong treatment * Drug toxicity

35. * Filamentous fungal keratitis –Aspergillus - Fusarium

36. * Greyish-white ulcer with indistinct margins * Surrounded by feathery infilterates * Ring infilterate * Endothelial plaque * Hypopyon

38. * Usually develops in pre-existing corneal disease or immunocompromised patient * Yellow-white ulcer * Dense suppuration

40. * Suppurative bacterial keratitis * Herpetic stromal necrotic keratitis

41. * Culture * Biopsy * Antifungal therapy – Initially broad- spectrum econazole 1% topically – Then depending upon sensitivity natamycin or imidazole for 6 weeks * Systemic ketoconazole * Therapeutic penetrating keratoplasty

42. * Protozoan – active (trophozoite) – dormant (cystic) * Common in swimmers and CL wearers

43. * Blurred vision and disproportionate pain * Patchy anterior stromal infilterates * Perineural infilterates (radial keratoneuritis) * Infilterates coalesce –ring abcess, ulceration and hypopyon * White satellite lesions

45. * Corneal scrappings stained with calcoflour white * Corneal biopsy * Treatment with chlorhexidine, polyhexamethylenebiguanide drops, dipropamidine and propamidine. * Therapeutic penetrating keratoplasty

46. Primary ocular herpes: - Blepharoconjunctivitis - Keatitis (punctate epithelial)

47. * Opaque cells arranged in a course punctate or stellate pattern * Central desquamation leads to a linear branching ulcer. –Fluorescein stain – Rose Bengal stain –Diminished corneal sensitivity * Anterior stromal infilterates * Geographical or amoeboid ulcer

50. * Herpes zoster keratitis * Healing corneal abrasion * Pseudodendrites due to soft contact lens * Acanthamoeba keratitis * Drug toxicity

51. * Antiviral therapy – Acycloguanosine 3% ointment – Trifluorothymidine 1% drops – Adenine arabinoside 3% ointment, 0.1% drops – Idoxuridine * Debridement (with sterile cotton- tipped bud 2mm beyond the edge of ulcer)

52. * Stromal necrotic keratitis * Disciform keratitis

53. * Predominantly affects children * Etiology – Tuberculosis – Delayed hypersensitivity reaction to staphylococcal or other bacterial antigen

54. * Photophobia, lacrimation and blepharospasm.

55. * Conjunctival: Pinkish-white nodule surrounded by hyperaemia * Corneal: May resolve spontaneously or extend radially to the cornea. May cause severe ulceration or perforation.

57. * Short course of topical steroids * Topical antibiotics

58. * Onset at puberty * Central or paracentral stromal thinning * Apical protrusion * Irregular astigmatism * Autosomal dominant transmission with incomplete penetrance proposed

59. * By keratometry: - Mild ( 54 D) * By morphology: - Nipple cones – Oval cones – Globus cones

60. * Ophthalmoscopy: Oil droplet reflex * Retinoscopy: Irregular scissor reflex * Keratometry: Irregular astigmatism (principal meridians no longer 90 degree apart and mires cannot be superimposed) * Placido disc: Irregular reflected ring * Slit-lamp: Very fine deep stromal striae (Vogt lines).

61. * Decreased visual acuity * Munson sign * Fleischer ring * Corneal scarring * Acute hydrops

65. * Spectacle correction * Contact lenses * Penetrating keratoplasty