THE CORNEA

By

MUHAMMED FASAL . ABsc OPTOMETRY

AL SALAMA EYE RESERCH FOUNDATIONPERINTHALMANNA

THE CORNEATHE CORNEA

GROSS ANATOMY GROSS 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 11mm Vertical 11mm Thickness: Central 0.5 - 0.6mm Thickness: Central 0.5 - 0.6mm Peripheral 0.8 – 1.0mmPeripheral 0.8 – 1.0mm Radius of Curvature : Anterior 8 mm Radius 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 ?)

5 LAYERS5 LAYERS

(1) Epithelium St. Squamous Nonkeratinised (5-6 St. Squamous Nonkeratinised (5-6

layers)layers) Surface Surface Flat Flat cells (2-3 layers)cells (2-3 layers)

Intermed. Intermed. Polyhedral Polyhedral cells (2-3 cells (2-3 layers)layers)

Basal Basal ColumnarColumnar cells (one layer) cells (one layer)

(2) (2) Bowman’s layer Structure less (Acellular) Structure less (Acellular)

condensationcondensation Never regenerateNever regenerate

Ends as a round borderEnds as a round border

MINUTE MINUTE ANATOMYANATOMY

(3) THE STROMA (Substantia (3) THE STROMA (Substantia Propria)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 perpendicular to next

layerlayer - Cells ( present in Lacunae )- Cells ( present in Lacunae ) Corneal corpuscles ( Keratoblasts )Corneal corpuscles ( Keratoblasts ) Corneal metabolism & Corneal metabolism &

HealingHealing LeucocytesLeucocytes Inflammation

(4) DESCEMET’S MEMBRANE(4) DESCEMET’S MEMBRANE Homogenous, Structureless & Highly Homogenous, Structureless & Highly

ElasticElastic Resistant & Easily RegenerateResistant & Easily Regenerate

CORNEAL ENDOTHELIUMCORNEAL ENDOTHELIUM

One Layer of Polyhedral cellsOne Layer of Polyhedral cellsPartial dehydration of the corneaPartial dehydration of the corneaContinuous with the Endothelium of Continuous with the Endothelium of T MT M

NERVE SUPPLY OF THE CORNEANERVE SUPPLY OF THE CORNEA55THTH C.N C.N

OPHTH. division NASOCILIARY N 2 LongOPHTH. division NASOCILIARY N 2 Long CILIARY NCILIARY N

PAIN & COLD & SUPERFICIAL TOUCHPAIN & COLD & SUPERFICIAL TOUCH

CORNEAL PHYSIOLOGY CORNEAL PHYSIOLOGY NUTRITIONNUTRITION ( ( cornea is avascular cornea is avascular ))By diffusion By diffusion Tear Film Aqueous humour Limbal capillariesTear Film Aqueous humour Limbal capillaries

CORNEAL TRANSPARENCYCORNEAL TRANSPARENCY ( ( WHY WHY ?? ))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 CORNEARefractive 42 DRefractive 42 DProtective ( corneal reflex )Protective ( corneal reflex )

THE LIMBUS ( The Corneo-Scleral THE LIMBUS ( The Corneo-Scleral Junction )Junction )

Corneal epithelium Conjuctival Corneal epithelium Conjuctival epitheliumepithelium

Bowman’s membrane ends as a rounded borderBowman’s membrane ends as a rounded border

Substantia propria Sclera (irregular Substantia propria Sclera (irregular lamellae)lamellae)

Descemet’s membrane Trabecular Descemet’s membrane Trabecular meshworkmeshwork

Endothelium Endothelium of the Endothelium Endothelium of the angle of ACangle of AC

KERATITISKERATITIS KERATOSKERATOS CORNEACORNEA iTiS INFLAMMATIONiTiS INFLAMMATION

SUPERFICIAL KERATITISSUPERFICIAL KERATITIS Suppurative (Corneal Ulcer) Suppurative (Corneal Ulcer) NonSuppurative (Pannus)NonSuppurative (Pannus)

INTERSTITIAL KERATITISINTERSTITIAL KERATITIS Suppurative (Central Suppurative (Central Abscess)Abscess)

NonSuppurative (Diffuse or NonSuppurative (Diffuse or Local)Local)

DEEP KERATITISDEEP KERATITIS Suppurative (Post Abscess or Suppurative (Post Abscess or Ulcer)Ulcer)

NonSuppurative (Keratitis Profunda)NonSuppurative (Keratitis Profunda)

SUPPURATIVE SUPERFICIALSUPPURATIVE SUPERFICIAL KERATITSKERATITS

(CORNEAL ULCERS) (CORNEAL ULCERS)DEFINITIONDEFINITION Localized Necrosis of Sup. Localized Necrosis of Sup.

StromaStroma with destruction of overlying with destruction of overlying

Epith.Epith.

ETIOLOGYETIOLOGY Predisposing FactorsPredisposing Factors Precipitating FactorsPrecipitating Factors Causative OrganismsCausative Organisms

Predisposing Predisposing FactorsFactors

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 causes c) 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

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, Staph, StreptStrept….….

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.)

PATHOLOGY OF CORNEAL PATHOLOGY OF CORNEAL ULCERSULCERS

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

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

CLINICAL PICTURECLINICAL PICTURESymptomsSymptoms 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 visionSignsSigns Lids: OedemaLids: Oedema Conj.: Ciliary injectionConj.: Ciliary injection Cornea: Loss of luster, Grey infilt., Cornea: Loss of luster, Grey infilt.,

Oedema & +ve FTOedema & +ve FT Iris: Tender CB, Const. pupil & Iris: Tender CB, Const. pupil &

Aqueous flareAqueous flare

COMPLICATIONS OF CORNEAL COMPLICATIONS OF CORNEAL ULCERSULCERS

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

B) COMP. OF PERFORATED CORNEAL B) COMP. OF PERFORATED CORNEAL ULCERSULCERS

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

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 B) COMP. OF PERFORATED CORNEAL ULCERS (cont.)(cont.)

MANAGEMENT OF CORNEAL MANAGEMENT OF CORNEAL ULCERSULCERS

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

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

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)

CORNEAL ULCERSCORNEAL ULCERSPrimary 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

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

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

Treatment of Hypopyon Treatment of Hypopyon UlcerUlcer

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 )

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

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

Treatment Treatment

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)

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)

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

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

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

Treatment of Herpetic Epithelial Treatment of Herpetic Epithelial KeratitisKeratitis

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 dropsNB 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

Herpes Zoster OphthalmicusHerpes Zoster Ophthalmicus

Varicella-Zoster Virus Neurotropic Virus Old age - ImmunityClinical 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

Clinical Picture of H Z Ophthalmicus Retina : retinal vasculitis,detachment and necrosisOptic 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

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

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

Neurotrophic (Neuroparalytic) Neurotrophic (Neuroparalytic) KeratitisKeratitis

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 )

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

Mooren’s Ulcer ( chronic Mooren’s Ulcer ( chronic serpeginous ulcer )serpeginous ulcer )1ry non infective corneal ulcerRareCommon in old age

Aetiology ( unknown ) Limbal vasculitis Proteolytic enzymes necrosis of sup. layers Autoimmune diseaseSymptoms 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

Atheromatous Corneal UlcerAtheromatous Corneal Ulcer

Occurs on top of an old Leucoma

Hyaline degeneration with desquamation and 2ry infection

Resistant with bad healingCommonly perforates due to 2ry infectionTreatment Usual ttt Conjunctival flap Keratoplasty

Secondary Corneal Ulcers Secondary 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

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.

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

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

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

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

Keratitis profunda

Localised non suppurative deep KeratitisAetiology 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.

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

Band Shaped keratopathy Band Shaped keratopathy

Horizonal opacity ( in the interpalpebral area ) Old degenerated eyes Hyaline degeneration + Ca deposition

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)

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

KERATOGLOBUSKERATOGLOBUS

Congenital enlargement of the Anterior Segment

Signs Cornea: Large in diameter and curvature AC : Deep Iris : Tremulous Lens : SublaxationRefraction: Stationary myopia

DD : Buphthalmos

Treatment: Glasses

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