Infectious Keratitis (HSV Keratitis) PDF

Infectious Keratitis HSV Keratitis ○ Epithelial Replicates in corneal only Dendrite because of epithelial cell destruction Treat how it is supposed to and patient in 2 months, comes back and sees blurry and...

Infectious Keratitis HSV Keratitis ○ Epithelial Replicates in corneal only Dendrite because of epithelial cell destruction Treat how it is supposed to and patient in 2 months, comes back and sees blurry and no pain: immune response Signs: Earliest lesions are small, clear, raised vesicles in the epithelium ○ ○ These early lesions/vesicles can look like SPK initially. Always touch preauricular lymphoid to differentiate and herpes patients will have sensitivity when you press down on it. W/in 24 hr lesions, merge to form the dendritic and geographical ulcers True dendrite might stain w/ NaFl in the middle Swollen borders (raised) w/ live virus stain negatively Borders stain w/ rose Bengal Anterior uveitis Dendrites can merge and merges and turn into geographical lesions Healing dendrite can leave a typical “footprint” scar (sub-epithelial)  ○ Geographical lesion: past the epithelium and maybe reaching into anterior stroma and will leave scarring ^ ○ Foot print scars ^ Tx and M: Gentle debridement of ulcer ○ Anesthetize the eye and w/ a q-tip, clean the borders ANTI-VIRAL: Ganciclovir 0.15% opth. gel 1 drop 5x d until heals, then TID x 7 d ○ Gets into viral DNA and causes fragiliant DNA leading to its death ○ If you do not taper after it healed and make sure it is gone completely, you may get an immune response which then it’ll be harder to treat ○ This is our drug of choice PF lubricants b/w antiviral drops Cycloplegic: Scopolamine or Homatropine BID-TID Erythromycin ung can be used as prophylaxis ○ Can use together, not an issue F/U: q 2 days at the beginning, then once you see improvement q 3-5 days Trifluridine 1% (Viroptic) 1 gtt q 2 hr (no more than 9x), after 5-7 days: taper to 5x/day  ○ Problem is cytotoxicity; not only invades the bad cells but also good cells :( 97% cases resolve within 2 weeks w/ 1% viroptic Ophthalmologists have also done the debridement of the cornea + topical antibiotic to avoid secondary infections from virus such as epithelium being destroyed + oral tx and works well Alternative to ophthalmic tx ○ Fluoroquinolone QID after debridement x 7 days ○ Acyclovir 400 mg 5 x day or Valacyclovir 500 mg TID, Famciclovir 250 mg TID for 10-14 d ○ Stromal (immune keratitis) - we do not treat this because this is past preventative treatment Viral antigens diffuse into the stroma stimulating Ag-Ab rx causing stromal edema and permeability that leads to opacification and necrosis in severe cases Inflammation in stroma (interstitial) Signs: Limbitis ○ Iritis w/ KP’s in diffuse pattern ○ Stromal edema ○  Can have high IOP Decreased corneal sensation May become necrotizing: severe form of stromal keratitis, may require corneal transplant from perforation ○ Neovascularization w/ surrounding opacification = PANNUS (REFER)***** ○ Tx and M: Cycloplegia (Scopolamine 0.25% TID) Topical steroid (Prednisolone acetate 1% q 1 hr-QID) and very slowly tapered (usually over 10 weeks) ○ Must use steroid because it will reduce the amount of scarring, if not the scarring can lead to severe vision loss and we do not want this ○ Refer these patients Ganciclovir 0.15% opth. gel TID ACV 400 mg 5x day can be used in substitution of Ganciclovir, especially in keratouveitis (HEDS results) ○ If the patient has this involvement along w/ uveitis If secondary increased IOP– glaucoma medications (beta-blockers) ○ Trabeculitis ^ F/U daily ○ Neutrophic ulcer Structural damage to the basement membrane causing sterile ulcer Persists even w/ therapy that may lead to corneal melting and perforation  Signs: Results from an unresolved epithelial stage Horizontal ovoid size (2-8 mm) Can have smooth and rolled borders Most commonly in the inferior half of the cornea Differentiate from geographical ulcer Neutrophic ulcer Geographical ulcer Tx and M: If a small epithelial defect only ○ D/C antiviral, add PF artificial tears q 2-4 hr and ung hs ○ Add ab ointment QID x 2-3 days or until resolved If large ulcer ○ Ab ung QID, Cycloplege and BCL x 24 ○ Repeat procedure daily until healed ○ Consider doxycycline  ○ If no response w/ tx, consider amniotic membrane Bacterial Keratitis (in some mild form can be w/ bacterial conjunctivitis; but solely bacterial keratitis? We are talking about an ULCER) ○ 30,000 cases annually of bacterial ulcers in USA ○ Popularity of contact lenses contributes to rising of incidence of bacterial keratitis in developed world ○ 10-30/100,000 cl wearers develop infectious keratitis in USA, annually ○ Risk factors: Contact lens wear Corneal trauma Ocular surface disease: exposure keratopathy, dry eye, lid margin disease, entropion/ectropion, trichiasis Steroid use Immunocompromised (AIDS, chemotherapy) Post-operative Cataract surgery, lid hygiene due to chronic form of blepharitis ○ Etiology: Staphylococcus (⅓ rd) 14-33% cases in CL Streptococcus Pseudomonas (⅔ rd) 62-64% of ulcers in CL* Will eat up your cornea in a heartbeat (24 hrs) Moraxella Atypical mycobacteria, others ○ Symptoms: Pain Redness “White dot” in cornea Photophobia Discharge Decreased vision ○ Signs Vary according to severity and organism Strep. pneumonia (Gram +) Gray-yellow, disc-shaped ulcer Very suppurative or crystalline appearance Creeps to central cornea Severe uveitis and hypopyon is characteristic If not treated: corneal perforation  Staph. pneumoniae (Gram +) Well-defined white-grey or creamy stromal infiltrate that may enlarge to form a dense stromal abscess May have satellite lesions Uveitis and hypopyon (less than strep) P. aeruginosa (Gram - rods) Yellow-green mucopurulent discharge Exotoxins are very severe and will eat up cornea in 24 hrs Difficult to treat due to toxins that continue destroying the stroma and epithelium (even when the bacteria is no longer alive) Central w/ a gray infiltrate and overlying epithelial defect which progresses very rapidly and a ring ulcer can develop A ring ulcer that can cause corneal perforation within 24-48 hrs Area adjacent appears hazy secondary to edema Hypopyon and uveitis is common ○ Infectious ulcer: Location: more centralized Epithelial defect is larger and more painful A/C inflammation and flare are present Hypopyon present ○ Sterile ulcer: Location: tend to be more peripheral Subepithelial defect w/ overlying defect -> smaller than area of infiltration Will cause some sort of pain but not a lot A/C inflammation and flare not present ○ Tx and M for bacterial keratitis: REFER to corneal specialist Drawing of the corneal ulcer should be done, or a SL photograph for documentation of the size, shape, stromal infiltration, its density, depth, borders appearance and A/C reaction if (+) Culture, if CL, culture of cases Smears for fast information Moderate risk (1-1.5 mm, peripheral or mid-peripheral, A/C reaction and discharge) Fluoroquinolones: Ciprofloxacin (Ciloxan 0.3%), Ofloxaxin (Ocuflox 0.3%); Levofloxacin (Quixin, Iquix); Gatifloxacin (Zymar); Moxifloxacin (Vigamox) * gram (+) and (-), anaerobes, atypical Schedule ○ Day 1: Initial loading dose of 1 gtt every 5 minutes for 5 doses; then 1 gtt q 15 min for 3 doses, then q 30-60 minutes around the clock (24 hr) ○ Day 2: 2 gtts q hr  ○ Days 3-14: 2 gtt q 2-4 hr ○ After day 14: according to severity ○ F/U daily q first 7 days High risk (For larger ulcers involving visual axis and vision-threatening, significant A/C rxn and hypopyon and discharge) Require addition of fortified antibiotics and often pt’s are hospitalization Fortified Gentamycin or Tobramycin 4-5% (15-40 mg/ml) every 30-60 min alternated w/ fortified cephalosporin such as Cefazolin (50 mg/ml) or Vancomycin (24 mg/ml) q 1 hr (MRSA) Oral ab (Cipro 500 mg of Levofloxacin 500 mg) are given when ulcer involves the sclera or extremely deep ulcerations Cycloplegics to reduce uveal inflammation and prevent posterior synechia (Homatropin 5% BID-QID, Scopolamine 0.25% TID, or Atropine 1% BID*) ○ * if severe presentation: corticosteroids– to reduce any further stromal damage and reduce scarring in severe inflammation is given only after 48-72 hrs (bacterial control but lesion still open), Prednisolone acetate 1% or Lotemax q 2-4 hr Fungal Keratitis ○ Candida: non-filamentous, mostly in pre-existing cornea disease (dry eye, steroid use, exposure keratitis, herpes) ○ Aspergillus, Cephalosporium, Fusarium: filamentous, usually after trauma w/ vegetative, C/L contamination ○ Fungus are not easy to get rid of in eyes; refer!!! ○ Symptoms Pain Photophobia Decreased vision “White dot in my eye” ○ Signs Early ulcer could resemble a dendritic one w/ minimal signs of inflammation Gray or dirty white infiltrate w/ feathery borders surrounded by finger-like infiltrate satellite stromal lesions  Satellite lesions, hypopyon, endothelial plaque Immune ring w/ raised surface (Wessely Ring) and hyphae (feathery) edge Candida: multilobulated and “wet” ulcer Fusarium: large epithelial defect w/ multiple stromal infiltrate dry looking ○ Management Obtain stain: all ulcers of unknown etiology are treated as bacteria until proven by lab  Giemsa Calcofluor white If hyphae fragment in smear suggesting filamentous fungi Natamycin 5% (only commercial opth. drug us) ○ Most effective against fussarium & aspergillus, less effective against Candida ○ 1 gtt q 30 min-1 hr., including at night x several days and taper 4-6 weeks Scopolamine 0.25% TID ○ Can get uveitic so tx w/ Scopolamine If infection involves deeper stroma or is worsening add ○ Miconazole or Clotrimazole topical (prepared) (1-10 mg/ml) or Voriconazole topical 1% q 1 hr ○ Oral Itraconazole or Fluconazole 400 mg loading dose and then 200 mg PO QD If smear shows oval buds: Candida Treat w/ Amphotericin B prepared 0.15% (1.5 mg/ml) 1 gtt q 30 min-1 hr, 1st choice for Candida If fails to respond, add Fluconazole 0.5% topically w/ Fluconazole 200 mg orally Topical steroids are contraindicated! Allow more replication Only after weeks of therapy if high inflammation persists F/U daily until improvement and then accordingly (3-5 days) Signs of improvement: less pain, decreasing infiltrate size, blunting or “receding” leading edge, resolution or improvement of hypopyon or A/C reaction In nonresponsive or severe: penetrating keratoplasty Acanthamoeba Keratitis ○ Parasitic Protozoan capable of infecting injured corneas or contact lens patient (very bad) ○ Exists in the trophozoite (mobile and at initial infection) and the cyst form ○ Using tap water or homemade saline for cl ○ Swimming in hot tubs w/ Cl’s ○ Over 80% of cases are related to contact lens use ○ All lens types have been implicated, including soft, hard, gas-permeable, disposable, extended wear ○ Symptoms (worse than signs) Pain extreme compared to findings Lacrimation Photophobia Blepharospasm Reduced VA Had foreign body sensation Usually little or no discharge ○ Signs Epithelial/subepithelial infiltrate appearing as a pseudodendrite early on A non-suppurative ring infiltrate w/ epithelial defect develops over weeks Epithelial and stromal edema; elevated epithelial lesions Kerato-neuritis – corneal hypesthesia, (+) PA, conj. Follicular ○ Tx and M Refer to a corneal specialist Medical treatment Propamadine 0.1% (Brolene) – against trophozoites (available otc in Europe, not US) q 30 min-2h + Neosporin q 30 min-1h (Neomycin destroys the plasmalemma of org. and facilitates entry of drug) Polyhexamethylenene biguanide (PHMB) (Baquacil 0.02%) qh; antiseptic inhibits membrane function Cyclopegia: Atropine 1% TID F/U daily ○