Retina and Vitreous
Core concepts
Know retinal anatomy: layers, macula, fovea, and the blood-retinal barrier. Understand common conditions: diabetic retinopathy (non-proliferative and proliferative), retinal vein occlusion, retinal detachment (rhegmatogenous, tractional, exudative), and age-related macular degeneration (dry and wet).
Recognise key signs: microaneurysms, dot-blot haemorrhages, hard exudates, cotton wool spots (ischaemia), neovascularisation (proliferative disease), and vitreous haemorrhage. Know that rhegmatogenous detachment presents with flashes, floaters, and a curtain; exudative detachment shows shifting fluid. Understand anti-VEGF therapy for wet AMD and diabetic macular oedema.
Traps
- Confusing cotton wool spots (nerve fibre ischaemia) with hard exudates (lipid).
- Assuming all detachments need the same surgery.
- Forgetting that proliferative diabetic retinopathy needs panretinal photocoagulation or anti-VEGF.
- Missing that wet AMD causes sudden metamorphopsia.
Rule of thumb
Flashes + floaters + curtain = rhegmatogenous detachment until proven otherwise; urgent fundus examination is required.
Worked example
A diabetic patient has sudden visual loss with vitreous haemorrhage. Suspect proliferative diabetic retinopathy; arrange urgent review and consider vitrectomy if non-clearing.