Acute Change in Vision or Vision Loss (OSCE focused)

Candidate Instructions:You are a final-year medical student in the Emergency Department. A 65-year-old patient presents with sudden loss of vision in one eye. Take a focused history and explain your initial assessment and management plan to the examiner.

Key History Points 📝

• ⏱️ Onset: Sudden vs gradual, complete vs partial loss.
• 📍 Laterality: Monocular (retinal/optic nerve) vs binocular (occipital cortex, chiasm).
• ⚡ Character: Curtain coming down (amaurosis fugax/retinal artery occlusion), central scotoma (optic neuritis), flashing lights/floaters (retinal detachment).
• ⏳ Duration: Transient vs persistent (TIA vs permanent loss).
• 🔔 Associated symptoms: Headache, jaw claudication, scalp tenderness (GCA); limb weakness, speech disturbance (stroke); painful red eye (acute glaucoma, uveitis).
• 📜 PMHx/Risk Factors: AF, hypertension, diabetes, vascular disease, giant cell arteritis risk (age >50).
• 💊 Drugs: Anticoagulants, OCP, steroids.

Focused Examination 👀

• 🧍 General: check vitals, temporal tenderness (GCA), cardiovascular risk factors.
• 👁️ Eye exam: visual acuity, fields, pupillary reflexes (RAPD), fundoscopy (pale retina, cherry-red spot, haemorrhages, detachment).
• 🌡️ Look for red eye, corneal haze, shallow anterior chamber (glaucoma).
• 🧠 Neuro exam: focal deficits → stroke.

Key Differentials ⚖️

Investigations 🔬

• 🩸 Bloods: FBC, ESR/CRP (esp. if GCA suspected).
• 🧪 Blood glucose, lipid profile, coagulation screen.
• 👁️ Urgent ophthalmology slit-lamp and fundoscopy.
• 🧠 CT/MRI brain if stroke/TIA suspected.
• 🔎 Temporal artery biopsy if GCA suspected (but treat before result).

Immediate Management 🚑

• ⚠️ CRAO: Ocular massage, IV acetazolamide, consider anterior chamber paracentesis. Stroke team referral.
• 🔥 GCA: High-dose oral or IV steroids immediately (prednisolone 60 mg).
• 👓 Retinal detachment: Same-day ophthalmology referral for surgery.
• 🧪 Glaucoma: IV acetazolamide + topical beta-blocker, urgent ophthalmology.
• 🧠 Stroke: CT brain, thrombolysis/thrombectomy if indicated.

Examiner’s Marking Guide 📋

• Takes structured history covering onset, risk factors, and red-flags.
• Assesses for GCA, stroke, CRAO – life/vision-threatening emergencies.
• Performs key eye/neuro exam.
• Plans urgent investigations and treats before confirmation (e.g. steroids in GCA).
• Safety-netting and clear communication with senior/ophthalmology team.

🧑‍⚕️ Case Examples - Acute Change in Vision / Vision Loss

• Case 1 (Central Retinal Artery Occlusion): 🚨 A 70-year-old man with atrial fibrillation experiences sudden, painless monocular vision loss described as a "curtain coming down." Fundoscopy shows a pale retina with a cherry-red spot at the macula. Diagnosis: CRAO (ocular stroke). Teaching point: This is an ophthalmic emergency - consider ocular massage, acetazolamide, and urgent stroke/TIA workup.
• Case 2 (Retinal Detachment): 🌌 A 55-year-old woman reports flashes of light, floaters, followed by a shadow moving across her visual field. Fundoscopy reveals a detached, corrugated retina. Diagnosis: Retinal detachment. Teaching point: Presents with photopsia + floaters before field loss; requires urgent retinal surgery (laser or vitrectomy).
• Case 3 (Acute Angle-Closure Glaucoma): 🌡️ A 63-year-old woman presents with sudden painful red eye, blurred vision, and halos around lights. Exam: cloudy cornea, mid-dilated fixed pupil, IOP markedly raised. Diagnosis: Acute angle-closure glaucoma. Teaching point: True ophthalmic emergency; treat with acetazolamide IV, topical beta-blocker, pilocarpine, and urgent laser iridotomy.
• Case 4 (Ischaemic Optic Neuropathy - Giant Cell Arteritis): 🔥 A 75-year-old woman reports acute, painless vision loss in one eye, with headache, scalp tenderness, and jaw claudication. ESR/CRP markedly raised. Diagnosis: Arteritic anterior ischaemic optic neuropathy due to GCA. Teaching point: Immediate high-dose IV or oral steroids are sight-saving; temporal artery biopsy confirms diagnosis.
• Case 5 (Vitreous Haemorrhage in Diabetes): 🍬 A 58-year-old man with longstanding type 2 diabetes develops sudden onset of floaters and "cobwebs" obscuring vision in one eye. Fundoscopy is difficult due to hazy media. Diagnosis: Vitreous haemorrhage from proliferative diabetic retinopathy. Teaching point: Common in advanced diabetic eye disease; managed with observation, intravitreal anti-VEGF, or vitrectomy if persistent.