Features
• Proptosis (exophthalmos)
• Lid retraction ("stare"), lid lag on downgaze
• Diplopia (due to extraocular muscle fibrosis; inferior rectus most commonly affected)
• Exposure keratopathy
• Compressive optic neuropathy (↓ colour vision, RAPD)
Risk Factors
• Smoking
• Uncontrolled hyperthyroidism
Management
• Control thyroid dysfunction
• Smoking cessation
• Lubrication (mild cases)
• IV steroids or orbital decompression (optic nerve compression)
Features
• Bilateral ptosis
• Early-onset cataracts (Christmas tree appearance)
• Retinal pigmentary changes
• Weakness, myotonia, frontal balding, cardiac conduction defects
Genetics
• Autosomal dominant, CTG repeat expansion
• Lisch nodules (iris hamartomas, pigmented)
• Optic gliomas → visual loss
• Café-au-lait spots, neurofibromas
• Retinal astrocytic hamartomas
• Facial angiofibromas
• Cortical tubers, subependymal nodules, renal angiomyolipomas
Ocular Features
• Anterior or posterior uveitis
• Conjunctival granulomas
• Lacrimal gland enlargement → dry eyes
• Optic nerve involvement possible
Features
• Ptosis (fatigable) — worse as day progresses
• Variable diplopia
• No pupillary involvement (distinguishes from CN III palsy)
Diagnosis
• Ice pack test: improves ptosis
• AChR antibodies
• Edrophonium (Tensilon) test (historical)
Features
• Diabetic retinopathy (NPDR, PDR)
• Cataracts (earlier onset)
• Cranial nerve palsies (III, IV, VI):
o CN III palsy: pupil-sparing due to ischaemia
Features
• Hypertensive retinopathy:
o Silver/copper wiring
o Cotton wool spots
o Flame-shaped haemorrhages
o Papilloedema (malignant HTN)
Extra Revision Pearls
• Diplopia + proptosis clue → thyroid eye disease
• Ptosis + cataracts clue → myotonic dystrophy
• Lisch nodules clue → NF1
• Retinal astrocytoma clue → tuberous sclerosis
• Ptosis that improves with rest clue → myasthenia gravis
• Pupil-sparing third nerve palsy clue → diabetes microvascular ischaemia
• Cotton wool spots clue → diabetes or hypertension
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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.
