Retinal Vascular Diseases

Diabetic Retinopathy - Sweet Sight Sabotage

Pathogenesis: Chronic hyperglycemia → microangiopathy (pericyte loss, BM thickening) → capillary occlusion & leakage.

Key Features:

• NPDR (Non-Proliferative): Microaneurysms (earliest), dot/blot hemorrhages, hard exudates (leakage), cotton wool spots (ischemia), IRMA (Intraretinal Microvascular Abnormalities).
• PDR (Proliferative): Neovascularization (NVD: disc; NVE: elsewhere), Vitreous Hemorrhage, Tractional RD.
• CSME (Clinically Significant Macular Edema): Retinal thickening/hard exudates near fovea (e.g., within 500µm of center; or thickening ≥1DD within 1DD of center).

ETDRS Classification Highlights:

Management Outline:

Hypertensive Retinopathy - Pressure Cooker Peepers

Pathogenesis: Chronic ↑BP → vasospasm, endothelial damage, ↑permeability, blood-retinal barrier breakdown. Key Features:

• Arteriolar: Generalized/focal narrowing, straightening, AV nipping (Gunn's sign), copper wiring (early sclerosis), silver wiring (advanced sclerosis).
• Exudative: Cotton wool spots (NFL infarcts), flame/dot-blot hemorrhages, hard exudates, macular star.
• Optic disc: Papilledema (Grade IV, indicates malignant hypertension).

Keith-Wagener-Barker (KWB) Classification:

⭐ Presence of papilledema (KWB Grade IV) signifies malignant hypertension and is an ophthalmic emergency requiring urgent blood pressure control to prevent systemic and ocular complications.

Retinal Vessel Occlusions - Vision Traffic Jams

Sudden, painless vision loss is characteristic. Key differences between Central Retinal Vein Occlusion (CRVO) and Central Retinal Artery Occlusion (CRAO):

• Branch Retinal Artery Occlusion (BRAO): Affects a branch artery; sectoral retinal pallor. Possible embolus.

Risk Factors:

• Common: HTN, DM, HLD, smoking, OCPs, coagulopathies.
• Specific: Glaucoma (CRVO), atherosclerosis (CRAO).

Investigations: Fundoscopy, FFA, OCT. Systemic: BP, bloods (glucose, lipids, ESR/CRP for GCA).

Emergency Management of CRAO:

⭐ Suspect GCA in CRAO for patients >50 yrs with ↑ESR/CRP; start high-dose systemic steroids immediately to save fellow eye.

ROP & Other Syndromes - Tiny Vessels, Big Trouble

• Retinopathy of Prematurity (ROP)

  • Screening: Birth weight <1500g or Gestational Age <32 weeks; or BW 1500-2000g / GA 32-35 weeks + risk factors.
  • Zones: I (posterior pole), II (mid-periphery to nasal ora serrata), III (remaining temporal crescent).
  • Stages:

    Stage	Description
    1	Demarcation Line
    2	Ridge
    3	Ridge + Extraretinal Fibrovascular Proliferation
    4	Partial Retinal Detachment (A: extramacular, B: macular)
    5	Total Retinal Detachment

  • Plus Disease: Posterior pole vascular dilation & tortuosity. ⭐ > Indicates aggressive ROP, urgent treatment needed.
  • Management: Laser ablation, Anti-VEGF injections.

  

• Eales' Disease: Affects young males; idiopathic peripheral periphlebitis, neovascularization, recurrent vitreous hemorrhage.

• Sickle Cell Retinopathy: Proliferative stages feature "sea-fan" neovascularization (Stage 3); other stages: 1 (occlusion), 2 (A-V anastomoses), 4 (vitreous hemorrhage), 5 (RD).

High‑Yield Points - ⚡ Biggest Takeaways

• Diabetic Retinopathy: Leading cause of preventable blindness; NPDR (microaneurysms, hemorrhages) vs PDR (neovascularization).
• Hypertensive Retinopathy: Arteriolar narrowing, AV nipping, copper/silver wiring; papilledema in malignant HTN.
• CRAO: Sudden, painless, profound vision loss; cherry-red spot, box-carring. Ocular emergency.
• CRVO: Sudden, painless vision loss; "blood and thunder" fundus (diffuse hemorrhages, disc edema).
• BRVO: Most common at AV crossings (superotemporal); linked to HTN, arteriosclerosis.
• ROP: Premature infants, oxygen toxicity; peripheral avascular retina, neovascularization, risk of retinal detachment.