Retina and Vitreous (Medical and Surgical)
Core concepts
Master the retinal vascular diseases: diabetic retinopathy (NPDR/PDR, ETDRS grading, macular edema), retinal vein occlusion (CRVO vs. BRVO, ischemic vs. non-ischemic), and retinal artery occlusion (cherry-red spot, embolic sources). Know AMD (dry vs. wet, anti-VEGF), retinal detachment (rhegmatogenous vs. tractional vs. exudative, and the surgical options: scleral buckle, vitrectomy, pneumatic retinopexy), and macular hole staging and repair. Understand the role of OCT in diagnosis and monitoring.
Traps
The classic trap is CRVO vs. BRVO management: CRVO with macular edema responds to anti-VEGF, but ischemic CRVO requires monitoring for neovascular glaucoma. Another trap is rhegmatogenous vs. tractional detachment - tractional detachments are not repaired with a buckle. Also, central retinal artery occlusion is an emergency with a narrow window; do not confuse with ophthalmic artery occlusion (no cherry-red spot).
Worked example
A patient presents with sudden painless vision loss, a cherry-red spot, and a pale retina. Rule of thumb: CRAO is a stroke of the eye - check for embolic source (carotid, cardiac), but the retinal window is short; treat as an emergency and refer for systemic workup.