Cornea Remove: Thygeson’s, dystrophies? (2), peripheral ulcerative keratitis (2), surgery (intacs, CK, AK, PIOL, RLE, RK, etc.) Add NaFl photo

Baby picture of the day!

Sodium Fluorescein Used to stain dead or devitalized cells on the cornea and conjunctiva Pooling: green pools of fluorescein caused by dips in the tissue Negative staining: areas with no staining caused by elevation in the tissue

Keratopathies Dellen Exposure keratopathy Filamentary keratopathy Superficial punctate keratitis Thygeson’s superficial punctate keratopathy Neurotrophic keratopathy Recurrent corneal erosion Thermal/UV keratopathy

Dellen Stromal dehydration Fluorescein pooling

Superficial Punctate Keratitis (SPK) Non-specific inflammation of epithelium Causes: contact lenses, infection, dry eye, blepharitis, allergy/toxicity, trichiasis, etc.

Exposure Keratopathy Eyelid problem – incomplete closure #1 cause: nocturnal lagophthalmos Other causes: surgery, nerve palsy, CVA, thyroid eye disease, floppy eyelid syndrome

Filamentary Keratopathy Filaments = epithelial cells + mucous #1 cause: keratoconjunctivitis sicca Dryness  lids scrape against cornea friction chronic inflammation

Thygeson’s Superficial Punctate Keratopathy Young adult patients White conjunctiva with “crumb-like” central cornea Cluster of elevated white lesions in central cornea Lesions don’t stain (unlike SPK) Bilateral

Neurotrophic Keratopathy Think CN V1 (nasociliary) Trigeminal neuropathy from damage to the nerve Decreased corneal sensitivity  decreased wound healing Bad combination!

Recurrent Corneal Erosion (RCE) Poor hemidesmosome attachments between epithelium & BM due to previous trauma Patient awakens with acute pain

Thermal/UV Keratopathy UV-C (<300nm) is absorbed by the cornea Causes: sun, welding, snow, tanning Signs: SPK Symptoms: pain, photophobia, blur Symptoms begin 6-12 hours later!

Dry Eye Syndrome (DES): Definition A “multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface.” Associated systemic diseases: thyroid, arthritis, Sjogren’s, SLE Problematic meds: anticholinergic, antihistamines, hormone replacement, diuretics

DES: Testing Schirmer 1: no anesthetic, normal >10mm/5min Schirmer 2: anesthetic, normal >5mm/5min Phenol red thread: pH sensitive, normal >10mm/15sec Tear osmolarity Tear film instability (TBUT)

Aqueous tear-deficient DES: Categories Aqueous tear-deficient Evaporative Lack of lacrimal secretion Sjogren’s: includes autoantibodies & dry mouth Non-Sjogren’s = Lacrimal gland deficiency Water loss with normal lacrimal secretion Intrinsic = due to lid pathology Extrinsic = no lid pathology (vitamin deficiency, preservatives)

Ectasias Keratoconus Pellucid Marginal Degeneration (PMD) Keratoglobus All 3 can cause hydrops (tears in Descemet’s membrane)

Keratoconus Presents at puberty History of atopy Collagen fibril displacement, corneal thinning, corneal protrusion Fleischer’s ring = iron deposit at base of cone

Pellucid Marginal Degeneration (PMD) Presents in young adults Inferior thinning/protrusion of the cornea Against the rule (ATR) astigmatism = “kissing doves” / “crab claws” on topography 25min through PMD

Keratoglobus From birth General corneal thinning, worst in periphery Easier to perforate cornea

Dystrophies Anterior Stromal Posterior EMBD Meesman’s Reis-Buckler Macular Granular Lattice Schnyder’s Fuch’s Posterior Polymorphous All of these are autosomal dominant (AD) except macular dystrophy (AR)

EBMD = Map-Dot Fingerprint Epithelial Basement Membrane Dystrophy (EBMD) Excessive basement membrane production Can cause recurrent corneal erosions Negative staining shaped like map lines or fingerprints

Fuch’s Endothelial Dystrophy Older female patients Excess production of posterior lamina (Descemet’s membrane) Signs: guttata (clumps of Descemet’s BM), decreased endothelial cell density, stromal edema Symptoms: blurry vision am

Congenital Anomalies of the Cornea Megalocornea Microcornea Cornea plana Aniridia Haab’s Striae Axenfeld-Rieger syndrome Peter’s Anomaly Limbal dermoid

Megalocornea & Microcornea X-linked Diameter >13mm Myopic pts AD or AR inheritance Diameter <10mm Hyperopic pts

Cornea Plana AD or AR inheritance Corneal curvature equals scleral curvature Flat cornea

Aniridia Bilateral, AD inheritance Lack of iris tissue Often accompanied by foveal hypoplasia (reduces VA) & colobomas

Haab’s Striae Horizontal lines in Descemet’s membrane Occurs in congenital glaucoma

Peter’s Anomaly Present at birth Bilateral White cornea (leukoma)

Infectious Keratitis Bacterial Keratitis Fungal Keratitis Acanthamoeba Keratitis Herpes Simplex Virus (HSV) Herpes Zoster Virus (HZV)

Bacterial Keratitis Most common infectious keratitis Staphylococcus, Pseudomonas, Haemophilus influenzae, Moraxella catarrhalis Ulcer = infiltrates (immune) + epithelial defect Infectious ulcers stain

Fungal Keratitis Feathery edges Caused by plant trauma Candida infection indicates immune compromise

Acanthamoeba Keratitis Contact lens abuse (tap water) Pain out of proportion to signs Ring ulcer

Herpes Simplex Virus (HSV) DNA virus that infects the trigeminal ganglion (CN5) Decreases corneal sensitivity Type 1 (top) vs. Type 2 (bottom) Transmission

Neurotrophic Keratitis HSV Epithelial Disease Neurotrophic Keratitis Dendritic ulcers (stain) Geographic ulcers (stain) Reduced innervation to cornea Poor wound healing & reduced sensation

HSV Stromal Disease Endotheliitis Interstitial keratitis = neovascularization, immune ring, stromal thinning/scarring Disciform keratitis = most common Immune reaction causes stromal edema

Herpes Zoster Virus (HZV) Varicella Zoster Virus (VZV) Older patients or immune compromise Pre-zoster prodrome (fever, malaise, tingling) Active zoster = skin involvement respecting the vertical midline Hutchinson’s sign = tip of nose

Peripheral Ulcerative Keratitis Staph Marginal Keratitis Mooren’s Ulcer Type 3 hypersensitivity Sterile infiltrates where lid touches cornea Unilateral peripheral crescent-shaped ulcer

Corneal Deposits Whorl Keratopathy Fleischer’s ring Rust rings Hudson-Stahli lines Stocker’s line Ferry’s line Kayser-Fleischer Ring Band Keratopathy

Whorl Keratopathy Caused by systemic disease or medication No symptoms, no reduction in vision

Fleischer’s Ring Keratoconus Iron ring at the base of the con

Rust Rings Form around metallic corneal foreign bodies Must be removed along with foreign body

Hudson-Stahli Lines Iron lines in lower cornea No symptoms, no reduction in vision

Stocker’s Line Iron deposit along edge of pterygium

Ferry’s Line Iron deposits along edge of filtering bleb

Kayser-Fleischer Ring Copper deposition around edges of cornea Wilson’s disease (liver)

Band Keratopathy Calcium deposition Bowman’s layer

Arcus Senilis Corneal degeneration Most common peripheral corneal opacity Older patient or high cholesterol Unilateral arcus indicates contralateral carotid disease

Corneal Graft Rejection Type 4 Hypersensitivity 30% rejection rate in first year following transplant Epithelial, stromal, or endothelial Look for white blood cells

Refractive Surgery Types Contraindications RK PRK CK Intact RLE PIOL AK Age <18, unstable refraction Keratoconus Active herpes/infection Connective tissue disease Immune compromise (including diabetes) Large pupils

Radial Keratotomy (RK) Radial incisions flatten the corneal stroma Unstable Hyperopic shifts

Photorefractive Keratectomy (PRK) Outer cornea removed (epithelium, Bowman’s, some stroma) Less myopic because thinner cornea No flap Healing: 1-2 weeks Problem: stromal haze

Laser-assisted In Situ Keratomileusis (LASIK) Flap of cornea moved, laser applied beneath to thin stroma, then flap replaced Less myopic because thinner cornea Healing: 1-2 days Problem: dry eye

LASIK Complications Initial pain Infection Flap complications Corneal ectasia (thinning & protrusion, like keratoconus) Residual refractive error (under-correction) Glare Dry eye (#1) Epithelial ingrowth Corneal haze

Conductive Keratoplasty (CK) Treats hyperopia & presbyopia Shrink peripheral collagen fibers with radio energy Problem: regression

Intacs (Intrastromal corneal rings) PMMA ring in peripheral stroma Used for keratoconus Less myopic because ring flattens cornea Can be removed

Refractive Lens Extraction (RLE) Remove natural crystalline lens, replace with new lens (like cataract surgery) Works because lenses come in varying powers, select appropriate one

Phakic Intraocular Lens (PIOL) Lens implanted into an eye in front of the iris (natural crystalline lens remains intact) Great for high myopia Removable

Astigmatic Keratotomy (AK) Blade incisions relax the steeper meridian of the cornea

Contact Lens-Related Disorders Solution hypersensitivity/toxicity Corneal neovascularization Corneal warpage Contact lens deposits Superior epithelial arcuate lesion (SEAL)

Solution Hypersensitivity/Toxicity Diffuse SPK (superficial punctate keratitis)

Corneal Neovascularization Due to lack of oxygen (hypoxia) If it’s >1.5mm, switch contact lenses or stop wearing them

Corneal Warpage Cornea changes shape due to contact lenses GP lenses (gas permeable, “hard” lenses)

Contact Lens Deposits Deposits of tear components on contact lenses Clean lenses better!

Dimple Veiling Air bubbles trapped under a GP contact lens create divots in the cornea