Herpetic Keratitis
Features
• Pain, photophobia, watery discharge
• Reduced corneal sensation
• Dendritic ulcers on fluorescein staining (branching with terminal bulbs)
Important Points
• Avoid topical steroids — worsen infection
• Can lead to corneal scarring and vision loss
Treatment
• Topical or systemic aciclovir
Herpes Zoster Ophthalmicus
Features
• Reactivation of VZV in ophthalmic branch (V1) of trigeminal nerve
• Vesicular rash on forehead, upper eyelid
• Hutchinson’s sign: vesicles on the tip/side of the nose → high risk of ocular involvement
• Can cause keratitis, uveitis, scleritis
Treatment
• Oral aciclovir (started within 72 hours)
• Lubrication and ophthalmology referral
Chlamydial Conjunctivitis (Trachoma)
Features
• Chronic follicular conjunctivitis → scarring → entropion → trichiasis → corneal opacification
• Leading global infectious cause of preventable blindness
• Common in endemic areas (Africa, Asia)
Treatment
• Single-dose azithromycin
• Surgery for advanced cases (SAFE strategy: Surgery, Antibiotics, Facial hygiene, Environmental improvement)
Gonococcal Conjunctivitis
Features
• Profuse purulent discharge
• Rapid progression → corneal ulceration → perforation
Risk Groups
• Newborns (ophthalmia neonatorum)
• Sexually active adults
Treatment
• Systemic ceftriaxone (urgent)
• Copious irrigation
Other Infectious Uveitis
Syphilitic Uveitis
• Can cause interstitial keratitis or posterior uveitis
• "Salt and pepper" fundus
• Always screen for systemic syphilis (RPR, treponemal tests)
CMV Retinitis
• AIDS patients (CD4 <50)
• "Pizza pie" or "cottage cheese with ketchup" fundus appearance
• Progressive, painless vision loss
Toxoplasmosis
• Most common cause of infectious posterior uveitis
• "Headlight in the fog" — focal necrotising retinitis with vitritis
Extra Revision Pearls
• Dendritic ulcer clue → herpetic keratitis
• Tip of nose vesicles clue → zoster ophthalmicus (Hutchinson’s sign)
• Profuse purulent conjunctivitis clue → gonococcus (systemic treatment needed)
• Trichiasis clue → trachoma causing corneal damage
• CMV clue → AIDS with CD4 <50, "pizza pie" retina
• Avoid steroids clue → herpes simplex keratitis
