CORNEAL DEGENERATIONS AND PERIPHERAL CORNEAL ULCERS

Dr.Puneeth Isloor

DEGENERATIONS DYSTROPHY Peripherally located most often

Centrally located

Asymmetric Bilateral and symmetric Older age group Young age Progression could be slow or rapid

Progression is slow

Not inherited Corneal vascularisation

Inherited No vascularisation

Corneal degenerations refer to the conditions in which the normal cells undergo degenerative changes under the influence of age or some pathologic condition

CLASSIFICATION - BASED ON TYPE OF MATERIAL DEPOSITED

SCARRING -Pannus

-Epithelial basement membrane degeneration

-Corneal guttae-Retrocorneal fibrous mebrane

LIPID-Corneal Arcus

-Primary Lipid degenerations

-Lipid degeneration from vascularisation

CALCIUM-Calcific band keratopathy

-Focal degenerative calcification

-Toxic medications

-Calcareous degeneration

DROPLET KERATOPATHY

CORNEAL AMYLOIDOSIS

OTHER DEGENERATIONS

DEGENERATIVECORNEAL THINNING

Primary

Secondary

Polymorphic Amyloid stromal Degenerations

Secondary amyloiddegeneration

Limbal girdle of Vogt

Mosaic keratopathy

White ring of coats

Terrien ‘s Marginal degeneration

Age related marginalfurrow

Epithelium and basement membrane

Bowman’s Layer

Epithelial basement membrane degeneration

- Pannus ,Pterygium - Salzmann’s Nodular degeneration - Corneal arcus - Calcific Band keratopathy - Limbal girdle of Vogt - Nodular amyloid - Climatic droplet keratopathy - White ring of coats

STROMA ENDOTHELIUM AND DESCEMET’S MEMBRANE

-Scarring with or without vascularisation-Lipid degeneration-Polymorphic amyloid degeneration-Crocodile shagreen-Pre descemet’s filiform-Cornea farinata-Terrien ‘s Marginal degeneration

- Corneal arcus - Posterior collagenous layer -Cornea guttae -Hassal henle warts -Retrocorneal fibrous membrane

CLASSIFICATION BASED ON LAYER MOST PROMINENTLY INVOLVED

CORNEAL SCARRING AND VASCULARISATION-Avascular Scar-Vascular Scar

AVASCULAR SCARRING - Density graded as- Trace – Barely visible- Mild – A cloud like nebular opacity- Moderate –Macular opacity- Severe – White leukomatous opacity

- Scarring can occur at 3 levels- Subepithelial – Post Excimer laser- Stromal – Post microbial keratitis- Descemet’s membrane – interstitial keratitis

Management For vascularisation - If peripheral – intervention not necessary

-Laser photocoagulation – To decrease lipid leak into stroma To close large stromal vessels before PKP

- For Scars –- If scar is anterior to Bowman’s layer –

Mechanical scraping or peeling can be done.

- Anterior 2/3 of stroma – Lamellar keratoplasty- Full thickness scarring – Penetrating

keratoplasty

EPITHELIAL BASEMENT MEMBRANE DEGENERATION

- Map dot fingerprint changes in the epithelium and basement membrane

- Occurs in aged

- Due to abnormal synthesis of Basement membrane by the aging corneal epithelium

- Faint gray Map like subepithelial patches - most common superiorly

- Each Map has one distinct edge and fades off at the other edge – Coastline appearance.

- Fingerprints – Fine refractile parallel short lines in the cornea – “tram lines” or “gray mare s tail”

- Tear film – thin over the maps.Does not stain on fluorescein

Note the central epithelial basement membrane dystrophy (EBMD) in the visual axis of the right eye (left). In the left eye, note the trace paracentral EBMD (right).

HISTOPATH -Thickening of the basement membrane – gray map- B.M within epithelium –--- blocks

desquamation---- traps cells intraepithelially –-- Necrosis –---- Cogan s microcysts

- Subtle folds of the BM with fibrillogranular material – fingerprints

- CLINICAL - Irregular astigmatism -Recurrent epithelial erosions -Dry eye symptoms-particularly when there is increased evaporation of tear

Management - Symptomatic patients – - Lubricants- Peeling- In patients with astigmatism

and recurrent epithelial erosions. can be done with a surgical blade A gentle sweep towards the Limbus The limbal stem cells can differentiate into normal epithelial cells that produce normal BM.

SALZMANN NODULAR DEGENERATION - Non specific corneal response to chronic insult such as Phlyctenulosis,Trachoma and VKC- 3 groups- Asymptomatic- Symptomatic with foreign body sensation- Nodules overlying pupil with reduced visual acuity

- Focal , discrete ,avascular ,circular ,gray white,elevated opacities located subepithelial

- unilateral- Overlie areas of stromal scarring and

vascularisation- Persist after the inflammation has subsided- Refractile on retroillumination –PAS positive

material

SALZMANN S NODULAR SPHEROIDAL DEGENERATION

Gray white peripheral opacities

Golden yellow

Focal and discrete Multiple and confluent Unilateral in 80% cases Bilateral

HISTOPATHOLOGY - PAS positive material deposited between epithelium and Bowman s membrane- originating from damaged stromal fibrocytes

- Overlying epithelium is thin--- recurrent epithelial breakdown – stimulates further deposition of PAS – Irritation and Foreign body sensation

- IHC staining demonstrates decrease in adhesion molecules

- Collagen present between E and BM creates surgical cleavage plane during peeling

epithelial denudation as shown above (arrow 1), destruction of Bowman’s layer(arrow2)

MANAGEMENT- Asymptomatic nodules – no treatment- Symptomatic – Scraping along the edge

of the nodule until it lifts and peels off- Excimer laser can be used to remove

the superficial scarring - Lamellar or penetrating keratoplasty if

underlying corneal opacification and vascularisation is severe

LIPID DEGENERATIONSPATHOGENESIS- Can be – Primary/Idiopathic - - Secondary to corneal vascularisation - It’s a Vicious cycle Lipids leak from corneal vessels

Lipid phagocytosis by keratocytes and macrophages Mild chronic inflammatory response

Continued Neovascularisation

CORNEAL VESSELS AND LIPID DEPOSITS The lipid deposits leave a clear zone

around the vessels ---Lucid interval in Arcus

Lipid deposits In deep stromal keratitis --–deep vessels are invisible–-- but the clear zones around these vessels --- appear like snail tracks

HISTOPATH OF LIPID DEPOSITS - Central portion of the deposit is a dense yellow mass with spiculated edges -There is intracellular and extracellular lipid - Lipid laden macrophages and keratocytes

CORNEAL ARCUS- Most common peripheral corneal opacity

- Annular deposit of lipid parallel to corneal limbus- cholesterol,cholesterol esters,phospholipids ,TGs

- The lipid deposits leak from the limbal blood vessels

- Gray white with a 0.3mm lucid interval of Vogt - The Limbal margin is sharply demarcated and the inner margin is diffuse Starts at the level of Bowman s layer superiorly and inferiorly

It is more common in black and brown races. Prevalence is 75% in the seventh decade and 100% over the age of 80 years

- Vision is not affected- Bilateral usually

- Unilateral arcus - – Unilateral occlusive disease -Ocular hypotony after surgery or trauma --- Possibly due to increased vascular permeability

- Early deposits are best seen on Sclerotic scatter or broad tangential illumination

- In cross section on slit beam – Hourglass shape

-Corneal arcus is younger than 30 yr old pts – arcus juvenilis-In men younger than 50 years --familial type 2 and type 3 hyperlipoproteinemia--- Amount of arcus correlates with plasma LDL levels-Association with dupuytren s contracture

Differential diagnosis

- 1)Peripheral mosaic crocodile shagreen – Mosaic

pattern distinguishes it from diffuse haziness of arcus

- 2)Limbal girdle of Vogt – seen only at 3o clock and 9 o clock positions and subepithelial

BAND KERATOPATHY-There are 2 major types – 1)Calcific 2)Climatic droplet

CALCIFIC BAND SHAPED KERATOPATHY- A degenerative change associated with

deposition of calcium salts in Bowman’s Membrane ,Superficial stroma.

ETIOLOGY 1) Abnormal Calcium and Phosphorus metabolism -Hyperparathyroidism –primary & secondary -Chronic Renal Failure -Milk alkali syndrome 2) Keratoprosthesis and ocular prostheses

3) Ocular Diseases – a) Chronic Iridocyclitis of any type -JIA – pauciarticular variant -Sarcoidosis – Uveitis +Hypercalcemia -Phthisis Bulbi -Absolute glaucomab)Corneal diseases -Interstitial keratitis -Keratoconjunctivitis Sicca -Exposure keratitis -Following PKP

c)Exposure to toxins /drugs – 1)Mercury, 2) Phenyl mercuric nitrate(preservative) – affects inferonasal paracentral cornea, 3) Phosphate containing steroids, 4)Silicone oil in AC – 50% Cases and Viscoelastics

4 types of Calcific Keratopathy1) Calicific Band keratopathy2) Focal calcific plaques- Areas of acute

tissue injury /chronic epithelial defects3) Concentric Limbal calcific deposits –

systemic disorders of Ca and P4) Focal calcific deposits – use of topical

medication

5) PICTURE FROM LEIBOWITZ

PICTURE OF PATHOGENESIS FROM LEIBOWITZ

HISTOPATHOLOGY - In chronic ocular diseases – Extracellular calcium deposits in - Epithelial BM - Bowman s layer and - Superficial stroma.

- In cases of Hypercalcemia – Intracellular deposits may be seen. - Hydroxyapatite is deposited – adhere to collagen

- Earliest change on Microscopy – fine stippling of epithelial Basement membrane.

- STAINS USED Alizarin red –Von kossa method -Black Calcium red - Von kossa –Black Murexide – Stains calcium- Bluish purple Hydrogen peroxide –AgNO3-Stains Ca Black

Begins at Nasal and temporal limbus - Subepithelial plaques with sharp discrete edge that borders a clear zone next to limbus - Feathery edges that extend centrally - As the central borders meet – The narrow central part appears turbid and the periphery chalky white- Bow tie shaped opacity obliterates the

clear zone- Does not dissapear spontaneously.May reappear

3 types of clear zones in the band -Discrete round holes within the opacity – passage of nerves through BM

-Jagged intersecting fissures – corresponds to breaks in Bowman’s layer

-Large clear geographic patches --- site of sloughed plaques of calcium

- Early peripheral lesions are best seen ---on sclerotic scatter

- Retroillumination highlights clear zones

CLINICAL FEATURES - SYMPTOMS - Reduced Visual acuity - Foreign body sensation and grittiness

– conjunctival deposits can also contribute to this in cases due to hypercalcemia

Familial band shaped keratopathy - X linked recessive ocular disease -Affected 6 generations of Greek families in Cyprus and Episkopi -Produces a progressive,white opacity in early life -This later progresses to superficial stroma

Chronic Iridocyclitis - Pauciarticular JRA-- few systemic symptoms and 4 or less joints involved -Children – 3-6 monthly review to detect the iridocyclitis that cause BSK by 10yrs

Tissue injury calcification in Corneal diseases - Due to a combination of superficial corneal ulceration + tear film dysfunction

- Seen in RA , Ocular pemphigoid , Exposure keratitis ,renal failure and systemic alkalosis

-Full thickness –corneal calcification – occurs in severe dry eyes with persistent epithelial defects – “ Calcareous degeneration”

TOXIC CALCIFIC KERATOPATHY- Phenyl mercuric nitrate – used in

Pilocarpine preparation- Usually begins in the Inferonasal

paracentral cornea

-Topical steroid phosphate preparations can cause deposits in pts with Keratitis

CALCIFIC DEPOSITS IN SYSTEMIC DISEASES

CALCIFIC DEPOSITS IN SYSTEMIC DISEASES

CALCIFIC DEPOSITS IN OCULAR DISEASES

Remain peripheral as moon shaped arcs concentric to limbus

Progress centrally over to the pupillary area

Conjunctiva is also affected Usually limited to cornea Disappear when the metabolic disorder is corrected

Persist

CA * P product is elevated Normal

TREATMENT - EDTA is used to chelate the calcium. - Available commercially as a 150mg/ml concentration.It should be diluted 1:10 with sterile water .

- Topical anesthetic is instilled and lid speculum placed

- Corneal epithelium is scraped from the corneal surface with a scalpel -EDTA can be applied by 3 methods - Continuous irrigation - Cotton tipped applicator - Plastic or glass cylinder reservoir -10-12mm test tube

EDTA is applied for 15-20 minutes Topical anesthetic is reinstilled Corneal surface is gently rubbed with

an EDTA soaked microsponge until central calcium is removed

It is unnecessary to remove the peripheral calcium

Topical antibiotics, Cycloplegics and steroids to be administered

Soft contact lenses promotes epithelial regeneration

CLIMATIC DROPLET KERATOPATHY- Synonyms – Labrador Keratopathy -Bietti ‘s degeneration -Spheroidal degeneration -Actinic keratopathy

- Small to large ,refractile,yellowish droplets or spherules in the subepithelial zone and in the superficial stroma

- Multiple and confluent lesions and usually bilateral

- Risk factors – Dry Arid conditions- Extremes of temperature- Microtrauma of blown sand - Chronic UV radiation

-

- 4 categories- Primary-Type 1 – No previous ocular disease/scar,- bilateral - Peripheral corneal deposits

- Secondary –Type 2 - Prexisting ocular pathology- Paracentral and Central corneal deposits

- Conjunctival –type 3 – Spheroidal deposits over- pinguecula

Familial –type 4 – Central corneal deposits Strong family history

CLINICAL SYSTEM FOR GRADING Trace – Deposits in very small numbers One eye affected Only one end of interpalpebral strip in each eye if bilateral Grade 1 –Medial and lateral interpalpebral strips Sparing of central cornea Grade 2- Central cornea affected but visual acuity spared Grade 3 – Central cornea plus vision reduced Grade 4 –Elevated nodules present + Grade 3

PATHOLOGY- Globular deposits contain proteins rich

in Tryptophan ,Tyrosine,Cysteine and Cystine

- Exact composition of the droplets is unknown

3 possibilities – Biochemical alterations in cornea and conjunctiva - Fibrocyte derived - Plasma proteins that diffuse Stains with Toluidine blue ,basic fuschin

- Globules elevate the epithelium and cause erosions – Hence vision threatening

CLINICAL FEATURES - Primary – Droplets at 3o clock and 9 o clock -Gradually spread centrally -Confluent and coalesce -Elevated epithelium -Epithelial defects ----can cause --sterile ulcers with corneal perforation --secondary bacterial keratitis --deep corneal scarring --loss of corneal sensations

Picture of climatic droplet keratopathy

DIFFERENTIAL DIAGNOSIS - Salzmann ‘s nodular degeneration - Vogt s Limbal girdle – At 3 o clock and 9 o clock position .Annular chalk –white ,well defined appearance - Calcific band keratopathy Can coexist with spheroidal degeneration Is not elevated.Has cracks ,holes and geographic patches

MANAGEMENT - Prevention – Protection of the eyes from climatic insults -Excimer Laser phototherapeutic keratectomy can remove climatic droplet keratopathyFor grades Trace to Grade 3 lesions - Transepithelial phototherapeutic keratectomy For grade 4 nodules and secondary degeneration -Removal of nodules by scraping and peeling - followed by Phototherapeutic keratectomy

Severe corneal scarring – Then PKP or Lamellar KPIf coexisting cataract is present – then it is treated only after phototherapeutic keratectomy

TERRIEN ‘S MARGINAL DEGENERATION - Consists of Gradual thinning and ectasia of superior peripheral cornea -There is arcuate lipid deposition and vascularisation in pts aged >40 yrs -Bilateral and assymetric - 2 types of terrien s marginal degeneration

TYPE 1 TYPE 2

Younger individuals older patients

Associated with episcleritis and scleritis

Asymptomatic gradual thinning and ectasia

Begins at the superior corneal limbus with deposits of finely granular lipid material separated from the limbus by a clear zone.

Superior corneal thinning occurs and it forms a gutter

The gutter is centrally bound by an advancing edge of dense lipid deposits

Vascularisation can be observed across the thinned out area

Thinning progresses both centrally and circumferentially

With increased corneal thinning --- ectasia Can perforate after trauma Associated with - VKC - Pseudopterygium

D/D1)Pellucid Marginal degeneration - Occurs inferiorly -No lipid deposits/scarring/vessels2)Marginal thinning associated with RA and autoimmune diseases3) Late stages of Mooren’s ulcer4) Age related marginal furrow- Lucid interval of Vogt – becomes thinned out.

HISTOPATHOLOGY - Fibrillar degeneration -Bowman’s Layer and stromal lamellae- responsible for thinning - Cornea becomes thinner with appearance of a subepithelial pannus

MANAGEMENT - Initial management includes correction of astigmatism - With spectacle lenses -With contact lenses

- Surgical management in later stages 1)Lamellar keratoplasty in which a banana shaped lamellar donor is placed on the host bed

POLYMORPHIC AMYLOID DEGENERATION - Bilateral and Asymptomatic -Detected Incidentally on slit lamp examination -Amyloid deposits form discrete , punctate, refractile ,glass like deposits in the cornea in front of the Descemet’s Membrane -They appear centrally and can spread from posterior to anterior stroma

POLYMORPHIC AMYLOID DEGENERATION

GUTTAE

Diffuse and Isloated Central and confluent

Posterior stroma and Only indent the DM

Posterior surface of DM and disrupt endothelial mosaic

Do not progress Slowly progressive

Normal appearing DM Thickened descemet’s membrane

PELLUCID MARGINAL DEGENERATION- Bilateral disorder of unknown etiology- Affects both sexes equally and seen in 20-40 yrs

age

- Arcuate area of thinning in the inferior peripheral cornea in the absence of inflammation

- The area of thinning is 1-2 mm in width

- Separated from inferior limbus by 1-2 mm of normal thickness cornea.

- Cornea above the thinned area is normal in thickness and protrudes downwards – irregular astigmatism- Believed to be a variant of Keratoconus

MANAGEMENT - Large amount of irregular astigmatism – precludes treatment with spectacles and contact lenses

VOGT’S LIMBAL GIRDLE - Arcuate opacity that appears in the interpalpebral zone of corneal limbus at 3 o clock and 9 o clock positions

- Symmetric

- Occurs in 100% of individuals over 80 years of age

- It is an epithelial elastotic degeneration of collagen with particles of Calcium

2 types TYPE 1 TYPE 2

Concentric to limbus Nasal and temporal cornea

Clear Gap between it and the limbus

Usually contiguous with the conjunctiva

Less common

Has transparent Holes or cracks

More common

Overlying epithelium is intact and maybe hypertrophic

Picture of vogt’s limbal girdle

MOSAIC KERATOPATHY /CROCODILE SHAGREEN - Anterior corneal Mosaic - It is physiological

- Normal corneas exhibit a polygonal mosaic pattern when fluorescein is instilled and pressure is applied onto cornea

-When pressure is removed fluoresceins pools to create a mosaic pattern

- Can also be seen in ---ocular hypotony --keratoconus patients wearing hard contact lens ---after corneal trauma

- External pressure may change the normal tension of Bowman s layer and throw it into folds or ridges that indent the epithelium

ANTERIOR CROCODILE SHAGREEN - Gray polygonal corneal opacities that resemble a crocodile’s skin.It is an incidental finding.

-The gray white opacities are separated by clear lines at the level of Bowman’s membrane

-The pattern may be due to the way stromal collagen fibrils insert into Bowman’s layer

POSTERIOR CROCODILE SHAGREEN - Polygonal opacities appear in the Posterior stroma -Bilateral and does not affect vision -Does not involve descemet’s membrane or endothelium -Due to irregular alignment of stromal lamellae with a saw-tooth pattern . -0.5-2µm lacunae are present in stroma – represent areas of glycoprotein that differ from normal cornea

PRE-DESCEMET S DEGENERATIONCORNEA FARINATA - Fine ,flour like ,gray white opacities distributed in pre-descemet ‘s stroma in older individuals.

- Broad tangential illumination and retroillumination - Does not affect vision

- These opacities are intracytoplasmic vacuoles containing lipofuschin in stromal keratocytes.

-Pre –descemet’s opacities also occur in association with Keratoconus Posterior polymorphous dystrophy Ichthyosis

WHITE RING OF COATS - Superficial stromal discrete round white ring of dots around a clear centre -0.1-0.2 mm in diameter - Occurs after focal corneal injury -Mostly in men who have been exposed to occupational hazards -Histologically the materials may represent deposits of metallic foreign bodies - Incidental observation.Vision not affected

HASSAL HENLE BODIES -Descemet’s warts -occur with aging in the peripheral cornea -Posterior non banded layer of descemet’s membrane progressively thickens with age - localised excrescences of Descemet’s membrane produced by degenerating endothelial cells – due to overproduction of hyaline-Non specific response of the endothelium to injury

DELLEN - Depressions in the peripheral corneal surface that occur most often at temporal limbus

-Transient – 24 -48 hours

-Usually occur adjacent to areas of conjunctival elevation - Adjacent to areas of chemosis from pterygia, episcleritis,conjunctivitis,after ocular surgery

- Histopathologically shows thinning of corneal epithelium,Bowman’s membrane and Stroma -Treatment – use of ocular lubricants or pressure patching

PERIPHERAL ULCERSDEFINITION Peripheral ulcerative keratitis is a group of inflammatory destructive diseases involving the peripheral cornea whose final common pathway is characterized by corneal melting

ANATOMY AND PATHOGENESIS- Peripheral corneal anatomy predisposes to this condition- Peripheral cornea extends 3.5-4.5 mm from the visual axis and extends out to the junction of limbus and sclera

SPECIAL FEATURES OF PERIPHERAL CORNEA - Greater thickness with tight collagen bundle - Vascular arcades originating from anterior ciliary artery extends 0.5 mm into clear cornea

- Presence of more Langerhans dendritic cells - High concentration of IgM and C1

-Proximity to the conjunctival vessels and lymphatics provides the peripheral cornea access to the immune system

- Limbus and other conjunctival vessels – source of cytokines and collagenase and proteoglycanase

ETIOLOGIES - OCULAR NONINFECTIOUS - Acne rosacea -Mooren s ulcer -Traumatic ,post surgical -Exposure keratopathy -Terrien’s Marginal degeneration

- OCULAR INFECTIONS - Staphylococcal -Viral – Herpes -Acanthamoeba

SYSTEMIC NONINFECTIOUS - Rheumatoid Arthritis - Wegener’s Granulomatosis - PAN - SLE -Microscopic polyangiitis -Relapsing polychondritis -Churg strauss syndrome -Systemic sclerosis and Sjogren’s syndrome -Cicatricial pemphigoid/IBD/Sarcoidosis

SYSTEMIC INFECTIOUS – tuberculosis , Borreliosis Gonorrhea,dysentery Varicella zoster

MOOREN ‘S ULCER -Fewer than 300 cases in the world’s literature - Mooren’s ulcer is idiopathic – occuring in the absence of any systemic disorder

- Begins in clear cornea at the limbus and progresses centrally,circumferentially and posteriorly through the cornea

-The edge of the progressive ulcer is undermined - Painful ulcer – Pain is out of proportion to the signs - Low grade Iritis may be present and spontaneous or traumatic perforation can occur. - Slow destruction of the entire cornea occurs

PATHOLOGY It is believed to be a Type 3

hypersensitivity The chief inflammatory cell is neutrophils There is liberation of proteases and collagenases The conjunctiva adjacent to the destroyed cornea has plasma cells ---which secrete immunoglobulins

MANAGEMENT Mooren’s ulcer is mainly a diagnosis of exclusion All other causes of Peripheral ulcerative keratitis must be ruled out to arrive here

TREATMENT – Wide conjunctival resection to bare sclera –extending atleast 2 clock hours on either side of the peripheral ulcer and 4 mm posteriorly

Then resection of the overhanging lip of ulcerating corneaApplication of soft tissue adhesive and a soft contact lens to promote healing

Topical steroid therapy to be started – Prednisolone sodium phosphate 1% qid

Systemic tetracycline and 1% medroxyprogesterone are believed to have anticollagenolytic properties

Bilateral progressive Mooren’s – Cytotoxic chemotherapy – Systemic Methotrexate(7.5-15mg)

Azathioprine(2mg/kg/day) Cyclophosphamide(2mg/kg/day) Therapy to be continued for 6 months before

tapering

Rehabilitative Surgical therapy – - To be done only after the disease process is under control- It needs 2 procedures - Lamellar tectonic graft -Followed by definitive penetrating graft The lamellar graft is needed because the peripheral corneal stroma is insufficient to secureA penetrating graft.

ROSACEA KERATITIS - Rosacea is an inflammatory disorder of unknown etiology – chiefly affecting the skin

- Affects forehead ,nose , cheeks -More common in women in 4th decade -More severe manifestations occur in men

-Believed to be a type 4 hypersensitvity reaction to Demodex folliculorum

- Skin changes include Erythema,telangiectasia, Papules,pustules and hypertrophic sebaceous glands – causing Rhinophyma

OCULAR MANIFESTATION-Skin manifestations precede Corneal manifestations except in 10% of cases

- Blepharoconjunctivitis can occur –staphylococcal blepharitis

- Lid margins are thickened ,hyperemic with telangiectatic blood vessels and meibomitis

CORNEA –Affects inferior quadrant of cornea - Punctate epithelial erosions -Vascular invasion of the peripheral cornea with subepithelial infiltrates- Progresses centrally and circumferentially – ulceration ,scarring and perforation

Limbal involvement – Nodular conjunctivits,

Nodular scleritis TREATMENT- Lid scrubs for blepharitis- Oral tetracycline 250 mg QID for 6 – 8

weeks- After that dosage to be tapered by 250

mg per week- Tetracycline 250mg OD for a year

before discontinuing

PUK IN RHEUMATOID ARTHRITIS - Usually develops in association with adjacent necrotising scleritis -PATHOGENESIS- - Immune complex deposition in

peripheral cornea and limbal vessels and chemotaxis of inflammatory cells

There are 2 types of PUK in RA 1)Paracentral 2)Peripheral

Paracentral keratolysis –presents in patients with severe dry eyeMechanism – Altered epithelium

Inflammatory mediators enter the stroma

Stimulate a sterile keratolysis and a T cell infiltrateProgresses both centrally and circumferentially and is unresponsive to topical therapy

Peripheral keratolysis – There is an obliterative Microangiitis at the level of limbal vascular arcades

Deposition of Immune complexes in limbal vessels

Causes an immune microangiopathy and obliterative microangiitis

leakage of inflammatory cells and proteins

collagenases and proteases are released by neutrophils corneal melting

WEGENER ‘S GRANULOMATOSIS - Peripheral ulcerative keratitis is the initial ocular manifestation - Sometimes maybe preceded by

conjunctivitis or episcleritis- Crescentic peripheral corneal ulcer that

resembles Mooren’s ulcer - Scleral involvement is invariably present- this helps to differentiate it from

Moorens

HISTOPATHOLOGY – lymphocytes and plasma cells predominate the substantia propria

- The sclera and episclera may show a - Granulomatous reaction with epithelioid

cells and giant cells- Areas of active collagen degradation

can be seen- ANCA testing is positive- MANAGEMENT – Systemic

immunosuppression with cyclophosphamide and steroids is highly effective

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