Chapter 8: Eye Infections

Antibiotic Guidelines

Introduction

The eye and surrounding structures can become infected at multiple sites:‍

Site	Infection	Risks
Eyelid (margin)	Blepharitis	May affect conjunctiva/cornea
Eyelid (glands)	Hordeolum	Recurrence
Conjunctiva	Conjunctivitis	Trivial but can cause shrinkage
Cornea	Keratitis	Ulceration, scarring, blindness
Lacrimal system	Dacryocystitis	Recurrence, duct obstruction
Intraocular	Endophthalmitis, Retinitis	Retinal damage, blindness
Orbit	Orbital cellulitis	Spread of infection

High-risk patients include contact lens wearers, immunocompromised individuals, or those with trauma or surgery.

Eyelid Infections

Blepharitis

Chronic inflammation of the eyelids, classified as anterior or posterior.

Treatment includes:

Warm compresses
Lid hygiene
Topical antibiotics (e.g., chloramphenicol ointment)
Oral antibiotics
Artificial tears
Short-course topical steroids (with caution)
Refractory: topical ivermectin

Group	Primary Regimen	Alternatives	Pregnancy
Adults	Doxycycline 100 mg daily or Tetracycline 250 mg 6-hourly	Erythromycin 250–500 mg daily or Azithromycin 1g weekly ×3	Erythromycin 250 mg 6-hourly
Children <12 y/o	Erythromycin 10 mg/kg 6-hourly (taper with response)

Hordeolum (Stye)

Warm compresses
Cloxacillin 250–500 mg PO q6h (MSSA)
Cotrimoxazole 2 DS PO q12h (CA-MRSA)
Linezolid 600 mg PO q12h (HA-MRSA)

Conjunctivitis

Bacterial Conjunctivitis

Common pathogens: S. aureus, H. influenzae, S. pneumoniae
Treatment: Fluoroquinolone eye drops (e.g., ciprofloxacin)

Hyperacute Conjunctivitis

Neisseria gonorrhoeae – Emergency!

Ceftriaxone 1g IM (adults)
Ceftriaxone 125 mg IM (children)
Add azithromycin 1g PO if chlamydia suspected

Inclusion Conjunctivitis (Chlamydia)

Azithromycin 1g PO single dose
OR Doxycycline 100 mg PO 12-hourly × 7 days
PLUS Ceftriaxone if gonorrhoea suspected

Neonatal Conjunctivitis`‍`

Age	Likely Cause	Diagnosis
Day 1	Chemical	None
Day 2–5	N. gonorrhoeae	Gram stain, PCR
Day 5–14	C. trachomatis	PCR
Day 2–16	HSV	PCR

Treat according to cause:

Gonorrhoea: Ceftriaxone IM
Chlamydia: Erythromycin or Azithromycin PO × 14 days
HSV: IV Acyclovir

Trachoma

Azithromycin 1g PO single dose (adults)
Azithromycin 20 mg/kg (children)

Viral Conjunctivitis

Usually adenovirus.
Supportive care: lubricants, hygiene.

Keratitis

Bacterial

Urgent referral.
Fluoroquinolone drops hourly. Fortified drops for severe cases.

Fungal

Natamycin 5% drops hourly
Amphotericin B 0.15% for yeast
Add PO voriconazole for deep infection

Acanthamoeba

Chlorhexidine 0.02% + PHMB 0.02% drops
May need Brolene or Desmodine
Prolonged treatment often required

Viral (Herpes Simplex and Zoster)

HSV: Acyclovir 3% ointment, or Trifluridine drops
VZV: Valacyclovir 1g TID × 10 days

Lacrimal Infections

Canaliculitis

Warm compresses
Moxifloxacin drops
Refer for surgical clearance if needed

Dacryocystitis

Mild: Cephalexin, Amoxicillin-clavulanate, or Cotrimoxazole
Severe: IV Vancomycin + Ceftriaxone or Piperacillin-tazobactam

Endophthalmitis

Emergency referral.

Post-op: Intravitreal Vancomycin + Ceftazidime
Add PO Moxifloxacin 400 mg × 10 days
Trauma: Add IV coverage

Candida Endophthalmitis

IV Fluconazole or Amphotericin B
Intravitreal amphotericin or voriconazole if needed

Retinitis

Acute Retinal Necrosis (HSV/VZV)

Acyclovir IV or Valacyclovir PO
Intravitreal antivirals ± steroids

PORN (Progressive Outer Retinal Necrosis)

Seen in AIDS (CD4 <100)
Ganciclovir, Foscarnet ± ART

CMV Retinitis

Valganciclovir PO ± intravitreal injections

Orbital Cellulitis

Vancomycin + Ceftriaxone + Metronidazole
OR Piperacillin-tazobactam + Vancomycin
Treat for 2–3 weeks

Related Resources

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