Features
• Painless, gradual peripheral (tunnel) visual field loss
• Usually bilateral but asymmetric
• Optic disc cupping (increased cup-to-disc ratio)
• Thinning of neuroretinal rim
Pathophysiology
• Reduced aqueous outflow via trabecular meshwork
• Chronic, progressive optic neuropathy
Risk factors
• Age >40
• FHx
• African ancestry
• Myopia
• Diabetes, hypertension
Treatment
• First-line: Prostaglandin analogues (e.g., latanoprost) — ↑ uveoscleral outflow
• Beta-blockers (e.g., timolol) — ↓ aqueous production
• Carbonic anhydrase inhibitors (e.g., dorzolamide)
• Alpha-agonists (e.g., brimonidine)
• Laser trabeculoplasty or trabeculectomy if uncontrolled
Features
• Painful, sudden onset
• Red eye, blurred vision, haloes around lights
• Hard eye on palpation
• Mid-dilated, fixed pupil
• Nausea, vomiting
Pathophysiology
• Mechanical blockage of trabecular meshwork by iris
• Precipitated by mydriasis (e.g., dim light, medications)
Risk factors
• Hypermetropia (small anterior chamber)
• Elderly, East Asian ethnicity
• Family history
Management
• Emergency — vision-threatening
• Immediate medical:
o IV acetazolamide (reduces aqueous production)
o Topical beta-blocker and pilocarpine (after initial IOP reduction)
• Analgesia and antiemetics
• Definitive: Laser peripheral iridotomy (both eyes)
Causes
• Uveitis (inflammatory debris obstructing trabecular meshwork)
• Trauma (angle recession, hyphema)
• Steroid-induced (steroid responders)
• Neovascular (diabetes, CRVO)
Features
• Depend on underlying cause; may mimic open or closed-angle presentations
Extra Revision Pearls
• Painless peripheral loss clue → POAG; painful red eye clue → AACG
• Cup-to-disc ratio clue → >0.7 suggests glaucomatous damage
• Halos clue → corneal oedema from raised IOP (AACG) or cataract
• Hypermetropia clue → risk of angle-closure (shallow anterior chamber)
• Myopia clue → risk of POAG and retinal detachment
• Steroids clue → check for secondary glaucoma regularly
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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.
