CORNEAL DEGENERATIONS types by Dr supratim.pptx

This ppt explains various types corneal degenerations

1. CORNEAL DEGENERATIONS Dr. Supratim Datta 1st yr PGT TGMCH

2. Definition Corneal degeneration refers to the condition in which normal cells undergo some degenerative changes under the influence of age or some pathological condition

3. Characterstic Findings Features : No genetic predisposition Onset late Usually Unilateral Progression variable Peripheral Associated Local / Systemic diseases Degeneration results : Deposition Thinning Vascularisation Inflammation

4. Classification Age related Degenerations Arcus Senilis Arcus Juvenilis Vogt’s white limbal girdle Crocodile shangreen Cornea farinata Hassall-Henle bodies Pathological Degeneration Spheroidal degeneration Lipid degeneration Band keratopathy Salzmann’s nodular degeneration Terrien’s marginal degeneration Amyloid degeneration Furrow degeneration

5. Arcus senilis Common age related Annular lipid (phospholipids & cholesterol) Starts in the superior and inferior quadrant Progresses circumferentially forming a ring Opaque white grey or occassionally yellow band of opacity Approx 1mm wide band Central border diffuse and peripheral border sharp Clear zone: Lucid interval of Vogt (0.3 mm)

6. Arcus senilis

7. Arcus juvenilis Rare condition <40 years Raised Cholesterol & LDL Hyperliproteinemia mostly Type I and II Greater risk (4 X) of Coronary heart disease Asymmetrical Arcus : Carotid disease

8. Vogt’s White Limbal Girdle Age related Female > Male Bilateral Narrow, crescentic lines of chalk like flecks in the interpalpebral limbus ( at 9 and /or 3 ‘o’ clock) Located nasally more often temporally Histology : Hyperelastosis & hyaline deposition Asymptomatic condition

9. Vogt’s White Limbal Girdle Type I Variant of band keratopathy featuring ‘Swiss cheese’ hole pattern Clear area seperating the lesion from scleral margin Less prevelent > Male EEEDREE Type II Absence of hole pattern Lacks peripheral clear zone between arc and the limbus More prevelent

10. Vogt’s White Limbal Girdle Type I Type II

11. Crocodile Shagreen Age related degenerative condition with non familial pattern of occurence Asymptomatic Bilateral, Symmetrical More prominent Centrally Involving Anterior > posterior stroma Corneal mosaic pattern Resembles cobblestone or Crocodile skin Greyish white, polygonal stromal opacities separated by clear spaces Visually insignificant

12. Types Anterior crocodile shagreen Common than posterior Stroma thrown into folds at Bowman’s membrane Posterior crocodile shagreen Deeper stromal opacities May occur peripherally

13. Crocodile Shagreen

14. Cornea Farinata Farinata means “like wheat flour” Found in cornea of older patients Incidental finding Bilateral, Asymptomatic Very fine, dust like dots of tiny grey/white deposits Deposits may composed of lipofuscin in stomal keratocytes Deep central stroma, just anterior to DM Central, Retro illumination Visually insignificant

15. Hassall-Henle bodies Hassall- Henle bodies are drop like hyaline filled excrescence of Descemet’s membrane Seen over peripheral cornea Common senile change seen in the cornea Degenerating endothelial cells produces localised nodular thickening of Descemet’s membrane known as guttae

16. Hassall-Henle bodies Excrescences are best seen on Specular reflection: dark round holes

17. Spheroidal Degeneration Climatic droplet keratopathy, Labrador keratopathy, Beitti’s nodular degeneration, Fishermann keratitis,Corneal elastosis, Keratinoid corneal degeneration, Chronic actinic keratopathy Degeneration of cornea and / or the conjunctiva Higher prevelence: Areas with extreme temp, low humidity, high wind, presence of sand, high level of exposure to the UV radiations, drying of cornea and repeated trauma Male to female ratio 2:1

18. Spheroidal Degeneration Primary Attributed to above mentioned risk factors and not associated with other ocular pathology Lesions presented at the horizontal limbus within the palpebral fissure and gradually progress towards the central cornea Secondary Occur secondary to ocular inflammation and corneal pathology Presented either U/L or B/L depending upon the etiology of the prior lesion Tertiary Associated with Conjunctival lesions and more frequently associated with Pinguecula Located at 3 and 9 ‘o’ clock positions interpalpebrally

19. Histopathology Extracellular amorphous globules which form large masses in Bowman’s membrane Globules made of protein material with elastotic features

20. Clinical Features Bilateral Peripheral cornea Coalesce Nodular Spread to involve central cornea Yellow or Amber color Homogenous Translucent Varying in sizes Fine droplets/ spherules/ globules

21. Clinical Features Appear oily, although not of lipid origin May be clear but often becomes cloudy and opaque over time Advanced lesions become larger and more nodular and lift the central corneal epithelium Located in superficial stroma, Bowman’s membrane, subepithelium and rarely in the epithelium in the advance stages Can involve conjunctiva also

22. Clinical Features

23. Johnson and Ghosh Grading System Trace : A small number of lesions that are found in one eye or only one end of interpalpebral strips in each eye Grade I : Lesions involving the interpalpebral cornea horizontally but not invoving the central cornea Grade II : Central cornea involvement without affecting the visual acuity Grade III : Central cornea involvement with decline in visual acuity Grade IV : Grade III features with lesion elevation

24. Management Conservative Protection against UV rays 🡪 Dark glasses Lubricating eye drops Surgical therapy Patient with corneal scarring and globules involving central visual axis , compromising vision or causing pain may require surgical intervention Superficial keratectomy Phototharapeutic Keratectomy Lamellar or Penetrating Keratoplasty

25. Complications Epithelial defects Recurrent Corneal erosions or sterile ulceration which may progress to microbial keratitis or perforate rapidly

26. Lipid degeneration Primary : Rare Peripheral, Central or Diffuse Occurs spontaneously Usually bilateral White or yellow stromal deposits Cholesterol, fats & phospholipids No vascularization Central can lead to diminution of vision

27. Lipid degeneration Secondary : More common Common in vascularized corneas due to previous injury/disease More commonly associated with herpex simplex and herpex zoster Other assocations- Interstitial keratitis, trauma,corneal hydrops and corneal ulceration White / yellow stromal deposits around blood vessels Lipid at Posterior stroma & Descemet’s

28. Lipid degeneration

29. Treatment Primary lipid degeneration- PKP Secondary lipid degeneration- Control of the underlying inflammatory disease Abnormal vascularisation may be eliminated by argon laser photocoagulation of arterial feeder vessel Needle point cautery to induce the absorption of the lipids through the destruction of the feeder vessels Intrastromal anti-VEGF agents for the corneal neovascularisation Penetrating Keratoplasty - Advanced disease

30. Band Keratopathy Calcium salts (Calcium hydroxyapitite) deposition in the Bowman’s membrane,epithelial basement membrane and superficial stroma Fine dust like basophilic deposits First seen at periphery Eventually the deposits may coalesce to form a horiz band of dense calcific plaque across the interpalpebral zone of the cornea Initial deposits are grey but gradually band progress to chalky white and with white dots in areas of corneal nerves

31. Causes Primary- Idiopathic Secondary- MC Ocular Causes Chronic anterior uveitis RD Surgery (Silicone filled eyes) Phthisis bulbi Chronic corneal oedema, Interstitial Keratitis Systemic causes 🡪 Renal failure, Vit D toxicity, Hypercalcaemia Chronic exposure to mercurial vapors or to mercurial preservatives (phenylmercuric nitrate/acetate) Age – related affecting otherwise healthy individual Hereditary- Familial cases and icthyosis

32. Etiopathogenesis Alteration of corneal metabolism that causes increased tissue Ph and precipitation of calcium Evaporation of tears because of exposure of the interpalpebral zone which causes calcium salt precipitation Histopathology : Calcium deposited as hydroxyapatite salt in the epithelial basement memb, basal epithelium & Bowman’s memb

33. Clinical Features Grey-white plaque with fine, dusty deposits in the horizontal band distribution on the cornea Sparing of extreme periphery of the cornea Lucent holes in plaques (representing corneal nerves through the BM) Flakey, peripheral plaque Advanced lesions – nodular and elevated with epithelial breakdown

34. Symptoms Decreased vision Foreign body sensation Ocular irritation Redness (occasionslly) Photophobia Visible cosmetic changes to the eyes

35. TREATMENT Mild cases (FB Sensation) -Artificial tear drops/gels Severe cases (DOV, cosmetic) -Chelation Large chips scraped – forceps, blade EDTA (0.5%-1.5%) soaked onto cotton tip; apply for 1-5 min Phototherapeutic keratectomy ( For residual opacification after initial EDTA chelation) Lamellar keratoplasty Treat underlying cause to prevent recurrences

36. Salzmann nodular degeneration A rare non inflammatory, slowly progressive, degenerative condition Grey-white to bluish nodules of hyaline tissue usually located anterior to Bowman’s layer

37. Risk factors Chronic ocular conditions: Trachoma Dry eye Chronic blepharitis Post viral keratitis Interstitial keratitis Vernal keratoconjunctivitis Exposure keratitis Previous trauma/ surgery

38. Characterstics Discrete, white to gray nodular lesions that elevate the epithelium Female > male Any age but generally 5 th to 6 th decade Bilateral (>50%) Shape- round, conical or wedge like Single or cluster in a circular array

39. Characterstics Nodules 0.5mm-2 mm in diameter Avascular Seperated from each other by clear cornea Anterior to Bowman’s layer Periphery > Central Superior and inferior cornea

40. Histopathology Thinning of epithelium with degeneration of basal cells Nodules made of collagenous tissue Bowman’s memb is damaged or locally absent and is replaced by eosinophilic material that is similar to basement membrane

41. Symptoms Asymptomatic (generally) But if symptomatic: Decreased visual acuity Foreign body sensation Epiphora Photophbia

42. AS-OCT Prominent, hyper-reflective, subepithelial deposits overlying Bowman’s membrane The corneal opacities are located under a normally reflective, thin epithelium The intraepithelial fibrosis overgrowth can result in corneal surface elevation above Bowman’s layer

43. AS-OCT Destruction of Bowman’s layer is the most important property in the pathophysiology of the disease It is replaced by a granular periodic acid schiff-positive (PAS-Positive) eosinophilic material Progression is determined by Bowman’s layer destruction Involement of Bowman’s layer indicates that surgical delamination of the nodule may be more difficult

44. Management Conservative management (In case of peripheral SND with FB sensation) Ocular Lubrication Short course of topical steroids and /or oral doxycycline Surgical Management (In case of raised nodule in central visual axis or failure of conservative management ) Superficial keratectomy Excimer laser Phototherapeutic keratectomy Lamellar keratoplasty Penetrating keratoplasty

45. Terrien marginal degeneration Slowly progressive non-ulcerative thinning of the peripheral cornea Usually bilateral, asymmetrical Male predilection (3:1) 2 nd to 5 th decade Exact etiology is unknown The pathology has been associated with Arthritis and Meibomian gland dysfunction

46. Terrien marginal degeneration Begins supero-nasally and progress circumferentially Lipid deposition at the edge of peripheral corneal thinning Lipid accumulation produces yellow white stromal opacities Superficial neovascularisation Intact corneal epithelium and an altered Bowman’s layer A distinct interval between the limbus and site of infiltration Ultimately, stromal degeneration occurs ,causing formation of a peripheral gutter Corneal perforation rate is 15%

47. TYPES Classic variant : More common Affects older population Usually asymptomatic Non-inflammatory Slow, chronic progression Inflammatory variant : Young patients More prominent inflammatory clinical course Faster evolution Hypersenstivity response to an immunogenic component of the basal membrane Thinning of the peripheral cornea, corneal opacification, neovascularization and possible positive fluorescein staining are typical signs of the inflammatory type

48. TMD Induces Irregular corneal astigmatism Reduced visual acuity Increased higher order aberrations

49. AS-OCT: Take precise and repeatable pachymetry measurements Compare the size of lesions during follow up Medical visits are recommended every 3 months when the minimal corneal thickness is 250 microns

50. Classic vs Inflammatory TMD Classic: Stroma has the same reflectivity as the normal cornea Inflammatory: Hyper-reflectivity in stroma Progressive stromal thinning induces corneal cavity formation with intact epithelial and endothelial layers around the lesion

51. Treatment Non – Surgical intervention Spectacles prescription Rigid gas permeable/ scleral contact lens Prosthetic replacement of the ocular surface ecosystem (PROSE) Avoid eye rubbing

52. Surgical procedure are considered when the corneal thickness decreases to 150 micron Tectonic Surgeries Conjunctival flaps Scleral autotransplantation AMG Corneal collagen cross linking Vision enhancing surgeries with or without Tectonic surgeries Epikeratophakia Lamellar keratoplasty Penetrating keratoplasty

53. Amyloid Degeneration Amyloid degeneration of cornea is characterised by deposition of Amyloid material underneath epithelium Very rare condition and occurs in primary(in healthy cornea) and Secondary forms (in a disease cornea) Acquired (secondary localized) corneal amyloidosis may be associated with corneal inflammation (such as Trachoma, keratoconus, leprosy) or intraocular disease (such as Uveitis, glaucoma) or may be secondary to trauma

54. Amyloid Degeneration Clinically, Amyloid deposits usually occurs as raised, yellow-pink nodular masses in the cornea In most cases, corneal vascularisation is associated with the Amyloid. The deposits may be refractile with retroillumination

55. Furrow Degeneration Senile marginal degeneration Thinning periphery- Furrow In presence of Arcus senilis, furrow is in lucid interval of vogt Fibrillar degeneration of stroma Defective vision is due to Astigmatism Treatment usually not necessary

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