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all about cornea

  2. 2. THE CORNEATHE CORNEA GROSS ANATOMYGROSS ANATOMY Anterior 1Anterior 1/6 of outer coat/6 of outer coat Curved & Domshaped Fibrous, Transparent & No BVsFibrous, Transparent & No BVs Diameter : Horizontal 12mmDiameter : Horizontal 12mm Vertical 11mmVertical 11mm Thickness: Central 0.5 - 0.6mmThickness: Central 0.5 - 0.6mm Peripheral 0.8 – 1.0mmPeripheral 0.8 – 1.0mm Radius of Curvature : Anterior 8 mmRadius of Curvature : Anterior 8 mm Posterior 7 mmPosterior 7 mm Refractive Index : 1.37 ?Refractive Index : 1.37 ? Refractive Power : 42 D ( what is Diopeter?)Refractive Power : 42 D ( what is Diopeter?) ( What is The LIMBUS ?)( What is The LIMBUS ?)
  3. 3. 5 LAYERS5 LAYERS (1) Epithelium St. Squamous Nonkeratinised (5-6 layers)St. Squamous Nonkeratinised (5-6 layers) SurfaceSurface FlatFlat cells (2-3 layers)cells (2-3 layers) Intermed.Intermed. PolyhedralPolyhedral cells (2-3 layers)cells (2-3 layers) BasalBasal ColumnarColumnar cells (one layer)cells (one layer) (2)(2) Bowman’s layer Structure less (Acellular) condensationStructure less (Acellular) condensation Never regenerateNever regenerate Ends as a round borderEnds as a round border MINUTE ANATOMYMINUTE ANATOMY
  4. 4. (3) THE STROMA (Substantia Propria)(3) THE STROMA (Substantia Propria) - 90% of corneal thickness- 90% of corneal thickness - C T Bundles ( Regular arrangement )- C T Bundles ( Regular arrangement ) - Bundles of each layer to each other- Bundles of each layer to each other perpendicular to next layerperpendicular to next layer - Cells ( present in Lacunae )- Cells ( present in Lacunae ) Corneal corpuscles ( Keratoblasts )Corneal corpuscles ( Keratoblasts ) Corneal metabolism & HealingCorneal metabolism & Healing LeucocytesLeucocytes Inflammation (4) DESCEMET’S MEMBRANE(4) DESCEMET’S MEMBRANE Homogenous, Structureless & Highly ElasticHomogenous, Structureless & Highly Elastic Resistant & Easily RegenerateResistant & Easily Regenerate
  5. 5. CORNEAL ENDOTHELIUMCORNEAL ENDOTHELIUM One Layer of Polyhedral cellsOne Layer of Polyhedral cells Partial dehydration of the corneaPartial dehydration of the cornea Continuous with the Endothelium ofContinuous with the Endothelium of T MT M NERVE SUPPLY OF THE CORNEANERVE SUPPLY OF THE CORNEA 55THTH C.NC.N OPHTH. division NASOCILIARY N 2 LongOPHTH. division NASOCILIARY N 2 Long CILIARY NCILIARY N PAIN & COLD & SUPERFICIAL TOUCHPAIN & COLD & SUPERFICIAL TOUCH
  6. 6. CORNEAL PHYSIOLOGYCORNEAL PHYSIOLOGY NUTRITIONNUTRITION (( cornea is avascularcornea is avascular )) By diffusionBy diffusion Tear Film Aqueous humour Limbal capillariesTear Film Aqueous humour Limbal capillaries CORNEAL TRANSPARENCYCORNEAL TRANSPARENCY (( WHYWHY ?? )) Anatomical Factors :Anatomical Factors : Cornea is avascularCornea is avascular Epithelium is nonkeratinizedEpithelium is nonkeratinized Stromal lamellae are regularStromal lamellae are regular Nerves are nonmyelinatedNerves are nonmyelinated Precorneal tear filmPrecorneal tear film Physiological Factors :Physiological Factors : Corneal dehydrationCorneal dehydration Uniform refractive indices of corneal tissueUniform refractive indices of corneal tissue FUNCTIONS OF THE CORNEAFUNCTIONS OF THE CORNEA Refractive 42 DRefractive 42 D Protective ( corneal reflex )Protective ( corneal reflex )
  7. 7. THE LIMBUS ( The Corneo-Scleral Junction )THE LIMBUS ( The Corneo-Scleral Junction )  Corneal epithelium Conjuctival epitheliumCorneal epithelium Conjuctival epithelium  Bowman’s membrane ends as a rounded borderBowman’s membrane ends as a rounded border  Substantia propria Sclera (irregular lamellae)Substantia propria Sclera (irregular lamellae)  Descemet’s membrane Trabecular meshworkDescemet’s membrane Trabecular meshwork  Endothelium Endothelium of the angle of ACEndothelium Endothelium of the angle of AC
  8. 8. KERATITISKERATITIS KERATOSKERATOS CORNEACORNEA iTiS INFLAMMATIONiTiS INFLAMMATION SUPERFICIAL KERATITISSUPERFICIAL KERATITIS Suppurative (Corneal Ulcer)Suppurative (Corneal Ulcer) NonSuppurative (Pannus)NonSuppurative (Pannus) INTERSTITIAL KERATITISINTERSTITIAL KERATITIS Suppurative (Central Abscess)Suppurative (Central Abscess) NonSuppurative (Diffuse or Local)NonSuppurative (Diffuse or Local) DEEP KERATITISDEEP KERATITIS Suppurative (Post Abscess or Ulcer)Suppurative (Post Abscess or Ulcer) NonSuppurative (Keratitis Profunda)NonSuppurative (Keratitis Profunda)
  9. 9. SUPPURATIVE SUPERFICIALSUPPURATIVE SUPERFICIAL KERATITSKERATITS (CORNEAL ULCERS)(CORNEAL ULCERS) DEFINITIONDEFINITION Localized Necrosis of Sup. StromaLocalized Necrosis of Sup. Stroma with destruction of overlying Epith.with destruction of overlying Epith. ETIOLOGYETIOLOGY Predisposing FactorsPredisposing Factors Precipitating FactorsPrecipitating Factors Causative OrganismsCausative Organisms
  10. 10. Predisposing FactorsPredisposing Factors LocalLocal a) Traumaa) Trauma - Abrasion- Abrasion (( Gono & Diph can invade normal epithelium ) -- FB , Rubbing lashes , PTDs , CLFB , Rubbing lashes , PTDs , CL b) Loss of corneal sensationsb) Loss of corneal sensations c) Ocular causesc) Ocular causes (( xerosis, A deficiency, Lagoph.).) d) Prolonged use of Steroidsd) Prolonged use of Steroids GeneralGeneral malnutrition Pregnancymalnutrition Pregnancy Diabetes Liver & Renal FailureDiabetes Liver & Renal Failure
  11. 11. PRECIPITATING FACTORSPRECIPITATING FACTORS Infection of nearby structuresInfection of nearby structures CAUSATIVE ORGANISMSCAUSATIVE ORGANISMS a) Bacterial e.g. Gono, Diphth., Pneumo,a) Bacterial e.g. Gono, Diphth., Pneumo, Staph, StreptStaph, Strept….…. b) Fungal ( not common )b) Fungal ( not common ) c) Viral e.g. Herpes Simplex and Zosterc) Viral e.g. Herpes Simplex and Zoster d) Acanthamoeba (C.L.)d) Acanthamoeba (C.L.)
  12. 12. PATHOLOGY OF CORNEAL ULCERSPATHOLOGY OF CORNEAL ULCERS Stage of InfiltrationStage of Infiltration Inflammatory reaction PNLs Grey disc shaped area - Oedema - Ciliary injectionGrey disc shaped area - Oedema - Ciliary injection Stage of ulceration A) Progressive unclean Stage Necrotic area ulcer with irregular Edge Necrotic Floor Surrounded by Dense reaction B) Regressive Clean Stage Large ulcer with regular Edge Deep, Clear, Transparent Floor Less infiltration
  13. 13. Stage of HealingStage of Healing A) Vascularization Limbal cap. Sup. Vasc. AB & Fibroblasts B) Fibrous tissue formation NB :NB : Epith. Mitosis & Migration B.M. Never regenerate Permanent scar Stroma Irregular F.T. Nebula or Leucoma D.M. Regenerates as an elastic membrane Endothelium Enlargement and Widening of cells
  14. 14. CLINICAL PICTURECLINICAL PICTURE SymptomsSymptoms Pain Severe ( FB or pricking sensation )Pain Severe ( FB or pricking sensation ) Irritation of nerve endingsIrritation of nerve endings PhotophobiaPhotophobia LacrimationLacrimation BlepharospasmBlepharospasm Diminution of visionDiminution of vision SignsSigns Lids: OedemaLids: Oedema Conj.: Ciliary injectionConj.: Ciliary injection Cornea: Loss of luster, Grey infilt., Oedema & +ve FTCornea: Loss of luster, Grey infilt., Oedema & +ve FT Iris: Tender CB, Const. pupil & Aqueous flareIris: Tender CB, Const. pupil & Aqueous flare
  15. 15. COMPLICATIONS OF CORNEAL ULCERSCOMPLICATIONS OF CORNEAL ULCERS A) Non Perforated corneal ulcer Early Complications (1)(1) 2ry Iridocyclitis : ( Toxins )2ry Iridocyclitis : ( Toxins ) (2) 2ry Glaucoma(2) 2ry Glaucoma : Open angle glaucoma: Open angle glaucoma (3) Descematocele : Small translucent bleb Not seen in children or T hypopyon ulcer Late Complications (Healing abnormalities) (1) Corneal opacity ( Nebula, Macula or Leucoma non adherent ) (2) Corneal Facet : rapid healing of the epith. (3) Keratectasia : ( weak corneal scar & IOP ) (4) Pseudoptregium
  16. 16. B) COMP. OF PERFORATED CORNEAL ULCERSB) COMP. OF PERFORATED CORNEAL ULCERS Early Complications (1) Iris Prolapse ( Big Para central or periph. Perforation ) (2) Anterior synechia ( Small periph. Perforation) (3) Corneal Fistula ( Small central perforation ) Lost AC IOP River Green Sign (4) Malposition of the Lens Sublaxation Ant. Dislocation Extrusion (5) Intra-ocular Hge Hyphema Vit., Ret. And choroidal hges (6) Macular and Optic Disc Oedema (7) Endo or Panophthalmitis
  17. 17. Late complications (1) Ant.Polar Cataract (Toxins ) (2) Leucoma Adherent ( Large Peripheral Perforation ) - AC irregular - Pupil pear shaped - IOP may be high - may be pigmented (3) Ant. Staphyloma ( partial or total ) (4) 2ry Glaucoma (closed angle by PAS ) (5) Atrophia bulbi ( atrophy of the cil. processes ) B) COMP. OF PERFORATED CORNEAL ULCERS (cont.)B) COMP. OF PERFORATED CORNEAL ULCERS (cont.)
  18. 18. MANAGEMENT OF CORNEAL ULCERSMANAGEMENT OF CORNEAL ULCERS INVESTIGATIONS + TREATMENT A) Corneal Scrapping ( Culture & Sensitivity ) Gram Stain for Bacteria Geimsa Stain for Trachoma & Acanthamoeba Silver Stain for Fungi B) Local ttt (1) Atropine sulphate 1% (3) Bandage or Dark Glasses (4) Counter irritant (2) Dressings ( Antibiotic dps & oint ) C) Systemic ttt Antibiotics Analgesics Vitamins A & C
  19. 19. D) Treatment of Complications (1) 2ry Glaucoma Usual ttt Antiglaucoma ttt paracentesis (2) Descematocele Bilateral Bandage or C L Avoid Straining Antiglaucoma ttt Hood Flap PKP (3) Perforation Small CyanoacrylateTissue Adhesive Large Hood Flap or PKP
  20. 20. E) Treatment of Corneal Opacity Central Nebula Glasses or CL Eximer Laser Lamellar KP Leucoma PKP In blind eye CCL Tattoo Treatment of Resistant CU Scrapping for Culture & Sensitivity Debridement Cautery Chemical Physical S.C. injection of AB Conjunctivoplasty Therapeutic KP (Lamellar or Penetrating)
  21. 21. CORNEAL ULCERSCORNEAL ULCERS Primary Corneal Ulcers - Infected Corneal ulcer Hypopyon Ulcers (Bacterial) Herpetic Ulcers (Viral) Mycotic Ulcers (Fungal) Acanthamoeba K (Protozoa) - Non-Infected Corneal ulcer Mooren’s Ulcer Keratomalacia Atheromatous Ulcer Ulcer with Lagophthalmos Neuroparalytic Ulcer Traumatic Ulcer Secondary Corneal Ulcers
  22. 22. HYPOPYON ULCERHYPOPYON ULCER Predisposing Factors Causative Agents: Pneumococci ( 80% ) Typical HU Morax Axenfield Bacillus (10%) Streptococci, Staphylococci, Pseudomonas and Fungi Clinical Picture Symptoms Pain Photophobia Lacrimation Blepharospasm Poor vision
  23. 23. Signs ( Acute Serpiginous ulcer ) - Haziness of the cornea ( loss of luster ) - Ciliary injection - Ulcer Near the centre Central advancing Edge Crescentic, undermined, preceded by dense infiltration Peripheral Healing Edge Flat, Epithelialized, Vascularized - Posterior Abscess : Dense infiltration in front of D M - Flourescein Test is +ve - Hypopyon in the Anterior Chamber ( Steril Pus ) PNL +Fibrin +Iris Pigment NB Perforation is common…why? Desematocele is Rare
  24. 24. Treatment of Hypopyon UlcerTreatment of Hypopyon Ulcer  Treatment of the cause ( Dacryocystectomy)  Usual ttt of corneal ulcer ABCD  Subconjunctival Injection of AB Cephazoline ( 100mg in 0.5 ml ) Tobramycin or Amikacine ( 20mg in o.5 ml )  Fortified Eye Drops Gentamycine or Tobramycine 15mg/ml.  Treatment of 2ry Glaucoma  Cautery in Resistant Cases ( Pure Carbolic A )
  25. 25. Atypical Hypopyon Ulcer Pyogenic organisms other than Pneumococci (20%) Common in children with increased resistance The Ulcer : Anywhere in the cornea Not Serpiginous, spreads in all directions Perforation is less common Desematocele may occur
  26. 26. Fungal UlcerFungal Ulcer Predisposing Factors Trauma with green plant Use of Steroids Contact Lenses Causative Agent Fusarium ( Filamentary fungi ) Candida ( Yeast forming fungi ) Aspergillus Clinical Picture Little or no ciliary Injection Raised, dry, grey white lesion with feathery margins Satellite lesions Stromal deep infiltrate Endothelial plaques Hypopyon
  27. 27. TreatmentTreatment  Usual ttt  Topical Antifungal ttt Natamycine 5% Miconazole 1% Amphotericin B o.3%  Systemic Antifungal ttt Ketoconazole 400mg/day Fluconazole 400mg/day ( In cases of deep Keratitis or failure of topical ttt )  Surgical ttt (PKP)
  28. 28. Acanthamoeba keratitisAcanthamoeba keratitis  Aetiology Protozoa ( Tap water and Swimming pools ) 70% of cases are C L wearers  Clinical Picture Punctate or Dendritic K Superficial Stromal K Partial or Complete ring of Infiltration Limbitis and Scleritis  Treatment Debridment Topical ttt Diamidines (Propamidine) Biguanides (Chlorohexidine 0.02%) Aminoglycosides (Neomycin) Antifungal (Miconazole and Ketoconazole)
  29. 29. Dendritic Corneal UlcerDendritic Corneal Ulcer Herpes Simplex Virus ( Epitheliotropic ) 1ry infection in early childhood Dormant in 5th Ganglion Recurrence with body resistance Predisposing factors Fevers (Influenza, Common cold and Pneumonia) Menstruation Drugs ( Immunosuppressive drugs or Steroids) Clinical Picture 1ry Ocular infection Dermato-blepharitis Follicular Conjunctivitis Epithelia Keratitis
  30. 30. Recurrent Ocular Infection (C/P of H. Keratitis) (A) Blepharoconjunctivitis (as 1ry infection) (B) Epithelial Keratitis Symptoms : as those of corneal ulcer Signs : A) SPK B) (Characters of Dendretic Herpetic Corneal Ulcer) Dendritic appearance Long course with tendency to Recurrence Superficial ( never perforate except in … ) Never Vascularised Hypothesia Double Stain Test C) Amoeboid Ulcer due to immunity or local Steroids
  31. 31. C)C) Stromal Keratitis (cell mediated immune reaction)  Interstitial Keratitis (unifocal or multifocal)  Disciform Keratitis (stromal inf. and epithelial odema +kps)  Necrotizing Keratitis Severe and rapidly progressive Overlying ulceration eccentric to infiltration -ve double stain Vascularisations D) Herpetic Iridocyclitis Complications Toxic punctate epithelial erosions (Antiviral drugs) Keratitis Metaherpetica Neurotrophic Keratitis
  32. 32. Treatment of Herpetic Epithelial KeratitisTreatment of Herpetic Epithelial Keratitis Local Antiviral Drugs Acyclovir ( Zovirax ) 3% eye ointment 5 times/day TFT ( Tri-Fluro-Thimidine ) eye drops Ara-A ( Vidarabine ) eye ointment IDU ( Iodo-deoxy-uridine ) eye drops NB Corticosteroids are contraindicated Treatment of Stromal H Keratitis Topical Corticosteroids Prophylactic Antiviral drugs Treatment of resistant cases Debridement ( to remove infected cells ) Cautery by Tinct. Iodine 7% in alcohol (kill the virus) Therapeutic L K
  33. 33. Herpes Zoster OphthalmicusHerpes Zoster Ophthalmicus Varicella-Zoster Virus Neurotropic Virus Old age - Immunity Clinical Picture : Lids : Dermatoblepharitis ( pain and rash ) Keratitis : ( Hutchinson’s rule ) Epithelial Keratitis ( Punctate or dendritic ) Interstitial Keratitis Scleritis Iris : 2ry iridocyclitis IOP : 2ry glaucoma Choroid : Focal choroiditis
  34. 34. Clinical Picture of H Z Ophthalmicus Retina : retinal vasculitis,detachment and necrosis Optic Nerve: Papillitis or Retrobulbar neuritis Orbit : Orbital oedema and Proptosis EOM : Paralytic Squint (3rd N. palsy) Treatment: Acyclovir tab. 800mg 5 times/ day for 7 days Steroids + Antibiotic skin oint. Steroids + Antibiotic eye drops Analgesics
  35. 35. Ulcer with LagophthalmosUlcer with Lagophthalmos  A primary ulcer in the lower 1/3 of the cornea Bell’s phenomena  Symptoms as usual corneal ulcer ( of vision is not marked..why?)  Signs Incomplete lid closure Ciliary injection & +ve flurorescein Ulcer in lower 1/3 with straight upper border  Treatment Usual ttt Methyl cellulose drops 0.5% several times/day ttt of the cause
  36. 36. KeratomalaciaKeratomalacia  Non infective ulceration and melting of the cornea Vitamin A (malnourished infants or malabsorption in adults)  Clinical Picture Loss of corneal luster Appearance of yellow dots (deg. Epithelium) Melting of the cornea No inflammatory reaction (quite eye) Corneal hypothesia Conjunctiva: dry with Bitot’s spots 2ry infection Endophthalmitis  Treatment Vit. A injection (200,000 IU/day) ttt of hypoproteinemia ( fresh plasma) Topical vit. A in early cases Surgical ttt in late cases : Conj. Flap Therapeutic CL PK
  37. 37. Neurotrophic (Neuroparalytic) KeratitisNeurotrophic (Neuroparalytic) Keratitis Corneal Sensation Aetiology Herpes Zoster Radical ttt of 5th Neuralgia ( Alcohol inj.) Damage of Orbital Ns (SOF & OA syndromes) Clinical Picture Symptoms No pain vision (central ulcer) Signs Epithelial exfoliation starts at the center Large deep ulcer perforation Treatment Usual ttt of corneal ulcer Long term Bandage Tarsorraphy ( median )
  38. 38. Traumatic Corneal ulcerTraumatic Corneal ulcer Trauma + 2ry Infection Trauma External: wounds, chemicals, burn & FB Local: Lash, PTD & PTC Treatment Usual ttt + ttt of the cause
  39. 39. Mooren’s Ulcer ( chronic serpeginous ulcer )Mooren’s Ulcer ( chronic serpeginous ulcer ) 1ry non infective corneal ulcer Rare Common in old age Aetiology ( unknown ) Limbal vasculitis Proteolytic enzymes necrosis of sup. layers Autoimmune disease Symptoms 12345 Signs Marginal grey infiltration Crescentic Ulcer Advanced edge ( undermined and creeps toward the center ) Healed edge ( Peripheral and vascularised ) Thin cornea Extension is slow and perforation is rare Treatment Usual ttt + Topical Steroids Topical Cyclosporine Conj. Excision // to the ulcer Lamellar keratoplasty Systemic Steroids & Immunosuppressive drugs
  40. 40. Atheromatous Corneal UlcerAtheromatous Corneal Ulcer Occurs on top of an old Leucoma Hyaline degeneration with desquamation and 2ry infection Resistant with bad healing Commonly perforates due to 2ry infection Treatment Usual ttt Conjunctival flap Keratoplasty
  41. 41. Secondary Corneal UlcersSecondary Corneal Ulcers  Ulcers 2ry to MPC Marginal, Crescentic and Superficial ( Rare ) Rapid healing  Ulcers 2ry to Gonococcal Conjunctivitis Marginal ulcer : Most common Ring ulcer : Multiple marginal ulcers Central and paracentral ulcers : usually perforate  Trachomatous Ulcers A) Typical Shape Horizontal Site In front of pannus Superficial Secondary infection is common Scarred by facet ( Healing ) B) Marginal, Central and Paracentral: not related to Pannus C) Mechanical: PTDs or Rubbing lashes
  42. 42. 2ry Corneal Ulcers2ry Corneal Ulcers  Phlyctenular Ulcers A) Limbal ulcer: ( ulcer of limbal phlycten ) Deep, when perforate peripheral Leucoma Adherent B) Ring ulcer: multiple phylectens C) Fascicular ulcer: Superficial Starts near the limbus Creeps to the center followed by leash of B.V.
  43. 43. INTERSTITIAL KERATITISINTERSTITIAL KERATITIS Non Suppurative iflammation of the Stroma + Uveitis Aetiology Delayed hypersensitivity to infectious organism - Syphilis, T.B., Leprosy - Herpes Simplex and Zoster, Measles and EBV (infectious M.) Types (1) Diffuse I.K. (2) Dsciform Keratitis
  44. 44. Syphilitic Interstitial Keratitis  Congenital Syphilis ( 95% ) 5 – 15 Years Bilateral Hutchinson’s triad ( I.K., Hutchinson’s teeth and Deafness )  Acquired Syphilis ( 5% ) 10 years after 1ry infection Unilateral Uveitis and Retinitis Symptoms Pain, photophobia, lacrimation, redness and vision
  45. 45. Signs of Syphilitic I.K.Signs of Syphilitic I.K. ( 1 ) Progressive Stage ( 2 weeks ) Severe infiltration ( haze ) + Vascularization Salmon patches ( reddish pink ) Ciliary injection ( 2 ) Florid stage ( 2 months ) Marked symptoms and signs vision up to HM ( 3 ) Regressive stage ( 2 years ) Residual interstitial corneal opacity Obliterated BV fine opaque lines Uveitis Investigations +ve Wassermann reaction
  46. 46. Treatment of Syphilitic I.K.Treatment of Syphilitic I.K. - Antisyphilitic ttt ( Penicillin ) - Atropine - Steroids - Keratoplasty for residual opacity DISCIFORM KERATITIS Antigen antibody reaction ( viral antigen ) H.S. & H.Z. Grey disc-shaped dense opacity Loss of corneal sensation Drop of vision Treatment Corticosteroids + Antiviral drugs Tarsorraphy
  47. 47. Keratitis profunda Localised non suppurative deep Keratitis Aetiology Allergic reaction to chronic infections e.g. TB Herpes Simplex or Zoster Trauma Idiopathic Clinical Picture Diffuse deep Keratitis Iridocyclitis Posterior Abscess and Ulcer Diffuse suppurative deep Keratitis Congenital, HU, Trauma, IK and endogenous with TB and S.
  48. 48. Degenerative ConditionsDegenerative Conditions ARCUS SENELIS Bilateral peripheral Fatty degeneration Common in old age Symptoms non Signs Arc shaped opacity in the upper ½ of cornea then lower ½ Clear zone between the opacity and Limbus (Lucid interval of vogt) Outer border is sharp and well defined Inner border is diffuse and illdefined NB ARCUS JUVENILIS may occur in hyperlipidemia or juv. DM
  49. 49. Band Shaped keratopathyBand Shaped keratopathy Horizonal opacity ( in the interpalpebral area ) Old degenerated eyes Hyaline degeneration + Ca deposition
  50. 50. KERATOCONUSKERATOCONUS  Definition Progressive conical protrusion of the cornea Starts at Puberty Weakness of central part  Incidence Females _ Atopy Bilateral +ve family history  Symptoms Gradual of vision - Myopia ( Curvature & Axial ) - irregular Astigmatism - Opacity at the apex of the cone Sudden of vision (Acute Hydrops i.e. acute edema due to rupture of DM)
  51. 51.  Signs of Keratoconus A) Early Retinoscopy ( RR is spinning or scissoring ) placido disc: ring distortion Keratometer B) Late - Cone shaped central cornea seen by Profile view Notching of the L.L. on looking down Manson’ Slit Lamp Thin apex and deep A.C. - Deep opacity at the apex of the cone Rupture of BM Folds of DM - Fleisher ring: brown ring the cone base ( hemosidren deposition ) DD Ant. Staph. - Keratectasia - Keratoglobus Treatment - Early casrs : Glasses or hard CL Corneal Collagen Cross linking with Riboflavin - Late cases : PKP
  52. 52. KERATOGLOBUSKERATOGLOBUS Congenital enlargement of the Anterior Segment Signs Cornea: Large in diameter and curvature AC : Deep Iris : Tremulous Lens : Sublaxation Refraction: Stationary myopia DD : Buphthalmos Treatment: Glasses
  53. 53. KERATOPLASTYKERATOPLASTY  Aim: Replacing the opaque part by a clear cadaveric cornea  Types: - Lamellar ( Superficial ) - Deep ( Penetrating ) NB: Both of them may be partial or total - Tectonic : Has a specific shape according to site and indication  Indications: - Optical a) Central corneal opacities b) Keratoconus - Therapeutic a) Resistant corneal ulcer b) Corneal fistula