Disorders of the Cornea

1. Disorders of the Cornea Kelli Y. Shaon, O.D.

2. Trauma/Injury • Corneal Abrasion/Corneal Foreign Body • Treatments - • Topical antibiotic to prevent infection (Vigamox, Zymar) • Cycloplegic to reduce inflammation • Pain medication • Follow-up: Daily until resolved • Bandage contact lens if large abrasion or poor healing

3. Corneal Dystrophy Bilateral Symmetrical Central Avascular Inherited Earlier onset Not systemic Dz related Non-inflammatory Usually only 1 corneal layer Corneal Degeneration Unilateral Asymmetrical Peripheral Vascular Not inherited Later onset Often associated w/ systemic disease Inflammation possible Multiple corneal layers Noninfectious Cornea

4. Corneal Dystrophy • Epithelium • EBMD (Map-dot-fingerprint dystrophy)** Common • Often superior Cornea • Common cause of RCE – • Treat like abrasion, until healed • After healed tears/ointments or 5% Muro BID-QID • If not associated w/ RCE, pt often asymptomatic • Often artificial tears & ointments if needed • Reis-Buckler’s Dystrophy • Sub-epithelial honeycomb pattern of opacification • Often younger patients • Meesman’s Dystrophy • Intraepithelial microcysts that are seen well on retroillumination • Rare

5. Corneal Dystrophy • Stromal • Lattice dystrophy • Amyloid deposits • Seen as branching whitish lines with haze • Macular dystrophy **(AR inheritance)** • Mucopolysaccarides deposition • Grayish-white spots with diffuse haze • Granular • Hyaline deposits • White snowflake like central opacities • Schnyder’s (Central crystalline) • Cholesterol deposits • Central, whitish crystalline like deposits

6. Corneal Dystrophy - Stromal

7. Corneal Dystrophy • Endothelium • Fuch’s Dystrophy • Corneal guttata – thickened Descemet’s mmb • Bullae in later stages, with varying degrees of edema • Congenital Hereditary Endo Dystrophy (CHED) • Bilateral corneal edema due to endo dysfunction • Present at birth

8. Corneal Degenerations • Corneal Depositions- • Arcus Senilis: bilateral, white lipid depositions • Band keratopathy: subepithelial calcium deposits @ 3:00 & 9:00; Often patchy appearance; Present in eyes w/ chronic inflammation • Salzmann’s nodular: elevated, bluish-white opaque deposits; Often secondary to chronic keratitis • Limbal Girdle of Vogt: bilateral white, needle like opacities in peripheral cornea - seen in elderly patients • Crocodile shagreen: bilateral, gray-white opacification in mosaic or cracked ice pattern

9. Corneal Degenerations

10. Corneal Degenerations • Peripheral degenerations – thinning • Terrien’s Marginal Degeneration: non-inflammatory superior peripheral thinning; induces ATR astigmatism • Furrow degeneration: thinning in clear zone b/w arcus and limbus • Dellen: thinning secondary to corneal drying adjacent area of tissue elevation • Pellucid Marginal degeneration: bilateral inferior peripheral corneal thinning • Peripheral Ulcerative Keratitis: (PUK) • Marginal Keratolysis – melting due to autoimmune/collagen disease • Mooren’s Ulcer – inflammatory, progressive peripheral thinning

11. Corneal Degenerations • Keratoconus: • Bilateral, cone-shaped central corneal thinning • Munson sign (protrusion of LL); Vogt’s striae (breaks in Bowman’s); Scarring in later stages

12. Additional Corneal Findings • Superficial Punctate Keratitis (SPK): pinpoint epithelial defects, best seen by staing with NaFL • Associated with dry eye, CL wear, blepharitis, medications, etc. • Filamentary keratitis: strands of mucous and devitalized epithelial cells still adherent to cornea • Thygeson’s SPK: bilateral, gray-white lesions (similar to sub-epithelial infiltrates) in white, quite eye – no staining

13. Additional Corneal Findings • Subepithelial infiltrates: • whitish round, fluffier (non-distinct edge) deposits • often seen with adenovirus • Keratic precipitates (KPs): • Deposits of inflammatory cells on endothelium (associated w/ uveitis) • Whitish-gray round, more defined deposits

14. Infectious Cornea • Bacterial Keratitis • Signs: Photophobia, pain, redness, VA decrease possible, mucous discharge • Symptoms: Infiltrate (white opacity) in stroma, ulcerative if overlying epi defect w/ staining • Etiology: Bacteria – Most common: • Staphylococcus: well defined gray-white infiltrate • Streptococcus:very purulent & AC reaction more common • Pseudomonas:progressive, necrotic infiltrate w/ mucopurulent discharge & sometime AC hypopyon – more common in CL wearer

15. Bacterial Keratitis/Ulcer • Treatment/Management: • NO STEROID, if epithelium defect • Cycloplegic for comfort – Homatropine 5% BID • Oral pain medication • Small, peripheral Ulcer - Vigamox or Zymar loading dose, followed by q1h & Ciloxin or torbramycin ung qhs, then taper gtts • Larger, Ulcer or infiltrate near visual axis – • Culture bacteria • Fortified antibiotics (Tobramycin q30min, alt w/ cefazolin q1h) • Start topical Vigamox with loading dose of gtt q5-15 x4-5 doses, then q 15 min for 3-5 doses, then q30-60 min aroind clock

16. Infectious Cornea • Fungal Keratitis • Often after ocular trauma w/ vegetable matter • Signs: Stromal gray-white opacity with feathery borders, satellite lesions possible, if treated bacterial – poor response to Antibiotic • Treatment: Natamycin 5% gtts q1-2 h around the clock with taper over next weeks

17. Infectious Cornea • Acanthamoeba • Often in CL wearer w/ poor hygeine (use of tap water, swimming in lenses, or hot tub use w/ CL) • Severe pain (not in proportion to ocular signs) • Treatment: Baquacl q1h or Brolene q 30m-2h; Cycloplegic, Oral pian meds – K transplant as last resort

18. Infectious Cornea • Herpes Simplex Virus (HSV) • Unilateral • The great Masquerader – presents in many forms • Dermatological – clear vesicles w/ crusting • Conjunctivitis – unilateral, follicular response (often due to vesicles shedding the virus) • Dendritic keratitis – thin linear branches w/ terminal bulbs – stains w/ NaFL & Rose bengal • Geographic ulcer – large epi defect • Stromal – stromal edema w/ intact epithelium • Uveitis – AC reaction often as result of stromal involvement

19. Herpes Simplex Virus (HSV) • Treatment: • Eyelid/Skin: Antibiotic ung – Erythromycin or Bacitracin ung BID; Oral Antivirals may be used to prevent primary infection • Conjunctivitis: Viroptic 1% 5x/day • Epitheial defect: NO Steroids, Viroptic 5x/day, cycloplegic (homatropine 5% BID) • Stromal: Cycloplegic, Viroptic for phophylaxis TID; Topical Steroid (Pred Forte 1%) QID if risk of vision loss, if NO overlying epi defect

20. Herpes Zoster Virus (HZV) • Obeys the midline – follows the dermatone • Hutchinson sign (rash involving tip of nose) may indicate more ocular involvement • Skin: rash respecting midline • Oral Antiviral (Valtrex 1g TID x 7-10 d) • Ung to lesions BID (same as HSV) • Corneal – Can have corneal Psuedo-dendrites (no terminal bulbs) or SPK • no antiviral gtts; Use tears PF freq & Steroids may help occasionally

21. HSV vs. HZV