Ophthalmic infections-2.pdf

COMMONWEALTH OF AUSTRALIA Copyright Regulations 1969 WARNING This material has been copied and communicated to you by or on behalf of the University of Sydney pursuant to Part VB of the Copyright Act 1968. (The Act). The material in this communication may be subject to copyr...

COMMONWEALTH OF AUSTRALIA Copyright Regulations 1969 WARNING This material has been copied and communicated to you by or on behalf of the University of Sydney pursuant to Part VB of the Copyright Act 1968. (The Act). The material in this communication may be subject to copyright under the Act. Any further copying or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice. Ophthalmic infections Dr Jonathan Penm [email protected] @JonPenm Learning objectives To know the symptoms of keratitis and endophthalmitis To know common causes and types of keratitis and endophthalmitis To know the treatments rationale for keratitis and endophthalmitis To know the role of the pharmacist for ophthalmic infections References AMH and TGs Common eye infections Conjunctivitis Inflammation of conjunctiva Blepharitis Inflammation of the eyelid margins Simple eye exam Always wash your hands before doing an eye exam Ask patient to look straight and view pupil, cornea and sclera Gently pull down the lower lid and ask the patient to look up Examine conjunctiva Ask patient to look at a near light then back at you Examine pupil reaction to light (pen-torch) Ask them to read print from a book Assess if visual acuity has changed Image from: http://www.osceskills.com/resources/Shine-a-pen-torch-into-one-eye.jpg Ophthalmic infections Anterior eye infections Microbial keratitis – Infection of the cornea Posterior eye infections Endophthalmitis Retinitis All sight threatening Pain Photophobia Reduced vision Image from: https://www.mdpi.com/1422-0067/22/22/12368/htm Microbial Keratitis - Corneal infections Corneal infection (may see white spots on cornea) Conjunctivitis does not affect the cornea Risk factors Contact lens (↑ use of contact lenses globally = ↑ microbial keratitis) Ocular Trauma Dry eyes Immunosuppression Causes of Microbial Keratitis Viral Keratitis Herpes Simplex Keratitis Bacterial Keratitis Fungal Keratitis Protozoal Keratitis Acanthamoeba Keratitis Cultures to identify cause Corneal scraping Image from: https://quizlet.com/gb/506509602/lecture-15-cd4-t-cell-subsets-1-of-2-th1-th2-cells-flash-cards/ Viral Keratitis Herpes Simplex Keratitis (e.g. from cold sore) Dendritic ulcer when using fluorescein corneal staining Virus confirmed using polymerase chain reaction If with shingles, most likely Herpes Zoster Ophthalmicus Need oral antivirals Viral Keratitis Herpes Simplex Keratitis (e.g. from cold sore) Bacterial Keratitis Caused by: Staphylococcus aureus (Gram +ve) Staphylococcus epidermidis (Gram +ve) Streptococcus pneumoniae (Gram +ve) Pseudomonas aeruginosa (Gram -ve) Corneal scrapings taken to culture Must do before treatment Bacterial Keratitis Every hour to ensure adequate levels in cornea Usually a very rough first night Note 1: Must be compounded Aminoglycosides are incompatible with Penicillin and Cephalosporins Alternate every 30 minutes Fungal Keratitis More common in tropical climates Aspergillus, Fusarium, or Candida Slower progression than bacterial or vial Worse prognosis Typical white spot with fluffy (filamentous) edges Fungal Keratitis Natamycin every hour Not available in Australia Need Special Access Scheme (SAS) approval by TGA Dr applies for approval. Approval allows pharmacists to order medicines from overseas Compound voriconazole eye drops Acanthamoeba Keratitis Acanthamoeba – Found in water and soil Rare cause of keratitis Trophozoite – feeding stage + mitosis Stress, lack of nutrients Nutrients, no drug pressure Acanthamoeba Keratitis A - early phase showing epithelial keratopathy B - stromal involvement and sterile hypopyon (pus in the anterior chamber) C & D - epithelial defect and ring stromal infiltrate E & F - corneal scarring with deep and superficial neovascularization. Image from: https://www.mdpi.com/2077-0383/10/5/942/htm Acanthamoeba Keratitis Treatment aims to eliminate cysts Topical biguanide every hour: polyhexamethylene biguanide (PMHB) and/or chlorhexidine (bis-biguanide) PHMB = swimming pool cleaner Adjunctive Therapy for Microbial Keratitis Cycloplegics (cause mydriasis/pupil dilation) Cycloplegia = paralysis of ciliary muscle Anticholinergics e.g. Atropine, cyclopentolate Relieve eye pain Paralysis of ciliary muscle (muscle in ciliary body) Prevent posterior synechia formation Iritis often occurs in keratits Iris can stick to lens = posterior synechia Pupil dilation prevents iris from sticking  Class questions Download Socrative app or visit www.socrative.com > Student login Room name: USYDPHARM Posterior eye infections Endophthalmitis – Inflammation of the inside of the eye Bacterial Fungal Viral Retinitis Symptoms Pain / Photophobia / Reduced vision Floaters Differentiate: Imaging Cultures Bacterial Endophthalmitis Hypopyon – pus in anterior chamber Types: Exogenous – Eye surgery or penetrating eye injury Endogenous – Spread of infection inside the body Commonly from: Staphylococci Streptococci Gram-negative bacilli (e.g. pseudomonas) (similar to bacterial keratitis) Bacterial Endophthalmitis Treatment: G -ve cover G +ve cover including MRSA = Methicillin resistant Staphylococcus aureus Intravitreal = injection into the vitreous space. Must be sterile Only use small volumes Maximum volume is 0.1 – 0.2 mL Fungal Endophthalmitis Rare cases caused by Fungus Candida Aspergillus Treatment Intravitreal amphotericin (covers candida) OR Intravitreal voriconazole (covers candida and aspergillus) Viral Retinitis Causes: Herpes virus Herpes simplex Varicella zoster Cytomegalovirus (immunocompromised only e.g. HIV) CMV retinitis: Typical opacity and red vasculature – “cottage cheese with tomato sauce” Viral Retinitis Can progress -> Acute retinal necrosis Treatment: Intravitreal foscarnet (pyrophosphate analogue) AND systemic therapy: Herpes simplex / Varicella zoster Valaciclovir/acyclovir oral tablets HCMV = Human CMV Cytomegalovirus Valganciclovir oral tablets Role of the Pharmacist Hygiene Referral Sterile compounding Hygiene Ensure lid is properly closed on eye drops Don’t touch tip of dropper Don’t let the inside of the lid touch anything Check discard date Wash hands before touching/rubbing eye Wash pillowcase, sheets and towels often Hot water and detergent Contact lens wearers Ensure they clean them properly Don’t use during/up to 24 hours after infection Referral Red eye is a common presentation in Community Pharmacy Any hint of keratitis/endophthalmitis should be referred Trauma or recent surgery/ eye injection Contact lens use Changes in vision Pain Photophobia Optometrists often have better equipment for this than GPs Sterile compounding Many eye drops/intravitreal injections need to be compounded How much to make? Many use eye drops hourly General rule: 1 mL = 20 drops Preservative free is ideal Immediately discard OR use for 24 hours if refrigerated Sterile compounding  Class questions Download Socrative app or visit www.socrative.com > Student login Room name: USYDPHARM