Keratoconus and Keratitis PDF

Keratoconus and Keratitis Keratoconus - Symptoms è Start in puberty and may progress for the next 10 - 20 y. - Is a non-inflammatory condition of the cornea...

Keratoconus and Keratitis Keratoconus - Symptoms è Start in puberty and may progress for the next 10 - 20 y. - Is a non-inflammatory condition of the cornea in which è Frequent changes in glasses & contact lenses. there is progressive central thinning of the cornea changing è Usually, bilateral involvement but asymmetrical. it from dome-shaped to cone-shaped. è Nearsightedness (myopia) and astigmatism - Causing vision to become blurred and distorted. è Blurred vision and distorted vision even when wearing - Like myopia they present at school age but the problem glasses and contact lenses doesn’t stop at 20 (progressive) - Classification based on - The classic signs of keratoconus è Severity: mild, moderate, severe è Fleischer's ring: resulted from iron deposition è Based on shape è Vogt's striae: longitudinal stress lines caused by corneal thinning P Nipple cones (small size, 5mm) è Apical scarring: scarring at the apex of the cone P Oval cones (larger, 5-6mm - ellipsoid) è Corneal thinning: central thinning P Globus cones (largest, > 6mm, may involve 75% of è Oil droplet sign: abnormal red reflex cornea) è Prominent corneal nerves è Acute corneal hydrops - Etiology : è Munson's sign (V-shape) è Sporadic (90%): imbalance of enzymes within the cornea è Heredity (10%): familial Hx (Jordan) è Others: P Eye rubbing as in case of allergic conjunctivitis. P Contact lenses wear. P Hormonal change. P Collagen systemic disease (down). - Pathophysiology (all layers are affected) è Thinning of the corneal stroma. - Diagnosis: è Ruptures in the Bowman layer. è Pentacam topography (diagnostic): measure the thickness è Deposition of iron in the basal epithelial cells, forming è Keratometer: measures the curvature the Fleischer ring. è Breaks in and folds close to the Descemet membrane - Treatment: result in acute hydrops and striae, respectively. è Hard contact lens, corneal ring, cornea transplant è Crosslinking of the stromal collagen (slow progression only)  Keratoconus and Keratitis Keratitis è Complications: P Thinning of cornea. - Bacterial keratitis (most common) P Sloughing of infected stroma. è Cause: Staph, Strep, P.aeruginosa (contact lens users) P Irregular astigmatism (uneven healing ulcer). è Predisposing factors: P Corneal ulcer and perforation P Contact lens wear. § Cause secondary endophthalmitis & loss of eyes. P Keratoconjunctivitis sicca (dry eye). § Vision lose P Prolonged use of topical steroids. § Corneal leukoma (scar formation &corneal vascularization) P Breach in the corneal epithelium (following surgery). P Decrease immunologic defense. è Treatment P Scraping for gram staining and culture. è Symptoms: P Initiate topical antibiotics: vancomycin + levofloxacin P Rapid onset of pain P If the corneal ulcer is small, peripheral and no P Light sensitivity (photophobia). impending perforation: monotherapy (ciprofloxacin) P Decreased vision. P Purulent discharge. - Viral keratitis a. Herpes simplex keratitis è Signs: P Cause: HSV 1 (common), HSV 2 (rarely). P Hypopyon (pus in the anterior chamber). P Symptoms P Ulceration of the epithelium. § Unilateral red eye P Conjunctival hyperemia (ciliary injection). § Vesicular skin rash and follicular conjunctivitis P White cornea opacity (abscess). § Variable degree of pain P Dense stromal infiltrate (subepithelial infiltrates). § Irritation, watery discharge, fever P Signs § Dendritic corneal ulcer (hallmark sign) § Inflammatory infiltration and edema § Loss of corneal transparency (severe cases) § Uveitis and glaucoma may accompany disease  Keratoconus and Keratitis P Diagnosis: by a slit lamp examination § Vesicular rash v About four days after onset v Unilateral over forehead, upper eyelid, nose. v Characteristically respecting the vertical midline. v Vesicles will discharge fluid and begin to scab after 1 w. v Pain is extreme during the inflammatory stage v patients are tremendously symptomatic. P Involvement of nasocillary nerve may cause: § Ocular: conjunctivitis, uveitis, iritis, keratitis, Virus invades and compromises the epithelial cells scleritis, chorioretinitis, optic neuritis surrounding the ulcer § Hutchinson’s Sign: The edges (terminal end-bulbs) will stain with rose Bengal or v Vesicular rash on nasal alae Lissamine green v Preceding herpes zoster ophthalmicus P Complications § Corneal scarring (can lead to loss of vision) § Chronic interstitial keratitis § Secondary iritis P Treatment § Most of cases resolve spontaneously within 3 w. P Treatment § Treatment is to $ stromal damage & scarring. § Oral and topical acyclovir § Topical antiviral (trifluridine or acyclovir ointment). § Steroid can be given because disease is due to § Don’t use topical steroids (geographical ulcer) immune reaction not virus itself but C/I in case of dendritic ulcer (risk of geographical ulcer) b. Herpes zoster ophthalmicus: § Cycloplegic agent (relax ciliary muscles): atropine, P Cause: VZV affects ophthalmic division of the CN5 cyclopentolate P Symptoms § Unilateral severe burning pain (4 days from onset)  Keratoconus and Keratitis - Fungal keratitis: - Disciform keratitis: è Rare , but they are very severe & devastating è Immunogenic reaction to herpes ag è Cause: filamentous (aspergillus or fusarium), candida è Resulting in disc or ring-shaped stromal edema & è Progression is slower & less painful than in bacterial clouding w/o ulceration è Keratomycosis is in consideration when we find lack of è Often associated with iritis. response to antibacterial therapy è Treated with steroids. è Signs P Filamentous keratitis: grayish infiltrate with indistinct Corneal ulcers or fluffy margins P Candida infection: yellow to white ulcer with - Presentation: painful acute loss of vision suppuration similar to bacterial keratitis. - Risk Factors: è Contact lens wear è Recent trauma è Poor lid apposition è History of ocular surgery è Treatment: topical antifungals “pimaricin 5%” è Chronic topical steroid use - Acanthamoeba keratitis: - Symptoms (depends on ulcers whether sterile or infectious) è Amoeba is found in air, soil, fresh or è Pain, usually severe brackish water è Redness è More commonly with increased soft è Tearing contact lens user. è Discharge è It may co-exist in patients having herpetic keratitis. è Photophobia è Severe persistent painful infection. è The corneal nerves are infiltrated. - Signs è Ring abscess is characteristic. è Dense corneal infiltrate with overlying epithelial defect è Diagnosis: scraping & culture è Hypopyon è Treatment: è Corneal destruction P A combination of topical anti-amoebic agents. è Ocular perforation P The use of topical steroids is controversial. P Long, toxic medications, and may unsuccessful  Keratoconus and Keratitis Iris prolapse - Results from full thickness corneal wound - Usually caused by penetrating trauma. - Complications: cataract, keratitis, blindness - Perforating injuries show entrance and exit wound - Treatment: immediate primary repair Hyphema - Defined as presence of RBCs in the AC. - Usually caused by blunt trauma to the eye. - Results from disruption of blood vessels in the iris or ciliary body. - Can be associated with internal ocular structural damage. - Complications: è Glaucoma (# IOP): high risk in case of sickle cell anemia è Retinal detachment è Corneal blood staining can cause permanent corneal changes - Prognosis: è Risk of rebleeding within 4-7 days è 8 ball hyphema carries bad prognosis - Treatment: è Semi siting position (45 degrees head elevation) è Cycloplegic agents, steroids è Surgical intervention (rarely), indications: P Affects the vision P Increase in IOP P Cosmetic