Retina and Vitreous
Concept anchors
Diabetic retinopathy is graded by the ETDRS scale: mild to severe non-proliferative ( haemorrhages, microaneurysms, venous beading, IRMA), then proliferative disease with neovascularization, vitreous haemorrhage and traction detachment. Macular edema is defined by thickening, not exudates, and is treated with anti-VEGF. Panretinal photocoagulation remains standard for high-risk proliferative disease.
Detachment and macula
Rhegmatogenous detachment follows a tear (flashes, floaters, then a curtain); traction detachment occurs in proliferative diabetic disease; exudative detachment arises from tumors, uveitis or choroidal neovascularization. Repair choices depend on location, media clarity and lens status. Macular hole staging and epiretinal membrane management are common question topics.
Vascular and degenerative disease
Central retinal artery occlusion shows a pale retina with a cherry-red spot and Hollenhorst plaques - it is a stroke equivalent requiring urgent workup. Central versus branch retinal vein occlusion differ in extent of haemorrhage and prognosis. Age-related macular degeneration: dry type with drusen and geographic atrophy; wet type with choroidal neovascular membrane treated by anti-VEGF.
Traps
Retinopathy of prematurity screening criteria (birth weight, gestation, postmenstrual age) and type 1 treatment thresholds are frequently tested. Hydroxychloroquine toxicity produces a parafoveal bullseye maculopathy detected early by multifocal ERG and optical coherence tomography. Always distinguish a retinal tear from a posterior vitreous detachment alone.
Rule of thumb
New flashes plus floaters with a visual field defect equals a retinal tear until proven otherwise - examine with scleral indentation and treat promptly.