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
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
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)
Features
• Profuse purulent discharge
• Rapid progression → corneal ulceration → perforation
Risk Groups
• Newborns (ophthalmia neonatorum)
• Sexually active adults
Treatment
• Systemic ceftriaxone (urgent)
• Copious irrigation
• Can cause interstitial keratitis or posterior uveitis
• "Salt and pepper" fundus
• Always screen for systemic syphilis (RPR, treponemal tests)
• AIDS patients (CD4 <50)
• "Pizza pie" or "cottage cheese with ketchup" fundus appearance
• Progressive, painless vision loss
• 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
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Author & Educational Disclaimer
Author:
Dr Phillip Cockrell BM FRCP DipClinEd
Dr Phillip Cockrell is a UK Consultant Physician in Internal Medicine, currently working at Queen Alexandra Hospital, Portsmouth University Hospitals NHS Trust. He has previously worked as a registrar across Intensive Care Medicine, Gastroenterology, Cardiology, Stroke Medicine, Acute Medicine, and Respiratory Medicine.
He has held senior leadership roles including Associate Clinical Director of the Acute Medical Unit, Clinical Director of Internal Medicine, and Chief of Medicine. Dr Cockrell has over 15 years’ experience in postgraduate medical education, having lectured extensively across the MRCP syllabus and contributed to MRCP revision teaching and course development.
Dr Cockrell holds a Bachelor of Medicine (BM), Fellowship of the Royal College of Physicians (FRCP), and a Diploma in Clinical Education (DipClinEd). His teaching approach is based on structured consolidation of complex medical topics to support efficient and effective revision for postgraduate examinations.
Purpose of this content:
The material on this page is intended solely for educational purposes to support revision for the MRCP (UK) Part 1 examination. It reflects examination-relevant principles of internal medicine and is designed to aid learning and pattern recognition.
Medical disclaimer:
This content is designed for postgraduate medical examination revision and does not constitute medical advice, diagnosis, or treatment guidance and must not be used as a substitute for professional clinical judgement, local guidelines, or specialist consultation. Clinical decisions should always be made in the context of individual patient circumstances and current national guidance.
