Inflammatory Retinal Diseases

Posterior Uveitis & Basics - Eye's Inner Turmoil

• Inflammation of posterior segment: choroid (choroiditis), retina (retinitis), or both (chorioretinitis); may involve retinal vessels (vasculitis).
• Key Symptoms: Floaters, ↓ vision, photophobia; pain less common than anterior uveitis.
• Cardinal Signs:
  • Vitritis (vitreous cells/haze) - hallmark.
  • Chorioretinal inflammatory lesions (yellowish/white patches, fuzzy borders).
  • Retinal vasculitis (sheathing, occlusion).
• Broad Etiology:
  • Infectious (e.g., Toxoplasma, TB, CMV, Syphilis).
  • Non-infectious/Autoimmune (e.g., Sarcoidosis, Behçet's, VKH, Birdshot).
• Diagnosis: Clinical; supported by FFA, ICG, OCT, lab investigations.

⭐ Vitritis, appearing as hazy vision and cells/flare in the vitreous, is a cardinal sign of posterior uveitis.

Infectious Retinal Disease - Microbial Mayhem

• Bacterial Retinitis/Endophthalmitis
  • Etiology: Post-op (e.g., cataract surgery), post-trauma, endogenous spread.
  • Signs: Rapid vision ↓, pain, hypopyon, severe vitritis.
  • Tx: Prompt intravitreal antibiotics (e.g., Vancomycin + Ceftazidime).
• Viral Retinitis
  • CMV Retinitis:
    • Setting: Immunocompromised (AIDS, CD4 < 50 cells/$\text{µL}$).
    • Appearance: Indolent; "pizza pie" / "cottage cheese & ketchup" (hemorrhages, exudates).
    • Tx: Ganciclovir (systemic/intravitreal), Foscarnet.
  • Acute Retinal Necrosis (ARN):
    • Etiology: HSV, VZV; often in immunocompetent individuals.
    • Features: Rapidly progressive peripheral necrotizing retinitis, occlusive vasculitis, prominent vitritis. "Brushfire" border.
    • Tx: IV Acyclovir, systemic steroids (after antivirals initiated).
  • Progressive Outer Retinal Necrosis (PORN):
    • Etiology: VZV; severe immunocompromise (e.g., AIDS).
    • Features: Rapid, widespread necrosis; minimal vitritis; poor prognosis.
    • Tx: Aggressive combination antivirals.
• Fungal Retinitis/Endophthalmitis
  • Etiology: Candida (common in IV drug users, indwelling catheters), Aspergillus.
  • Appearance: Fluffy white chorioretinal lesions; Candida may show "string of pearls" in vitreous.
  • Tx: Systemic & intravitreal antifungals (e.g., Amphotericin B, Voriconazole).
• Parasitic Retinochoroiditis
  • Toxoplasmosis: Most common cause of infectious posterior uveitis.

    ⭐ Toxoplasmic retinochoroiditis classically presents as a 'headlight in the fog' appearance due to focal necrotizing retinitis adjacent to an old pigmented scar, with overlying vitritis.

    • Tx: Triple therapy (Pyrimethamine, Sulfadiazine, Corticosteroids). 📌 Mnemonic: "PSC" for treatment.
  • Toxocariasis (Ocular Larva Migrans - OLM):
    • Population: Typically children (exposure to soil contaminated with dog/cat feces).
    • Presentation: Unilateral vision ↓, strabismus; posterior pole granuloma, peripheral granuloma, or chronic endophthalmitis.
    • Tx: Corticosteroids; antihelminthics (e.g., Albendazole) for active larva.

Non-Infectious Retinal Disease - Immune Overdrive

• Autoimmune/autoinflammatory processes targeting retina/uvea; often bilateral with systemic links. Management: corticosteroids, immunosuppressants.
• Behçet's Disease:
  • Systemic vasculitis (recurrent oral/genital ulcers, skin lesions).
  • Ocular: Severe panuveitis, hypopyon, occlusive retinal vasculitis (arteritis > phlebitis), retinal hemorrhages, neovascularization, optic atrophy.
  • HLA-B51 association.

  ⭐ Bilateral, occlusive retinal vasculitis is a hallmark of Behçet's disease and can lead to severe vision loss.

• Sarcoidosis:
  • Multisystem granulomatous disorder.
  • Ocular: Uveitis (any part), "candle-wax drippings" periphlebitis (venous sheathing), choroidal/optic nerve granulomas, CME.
  • ↑ Serum ACE, lysozyme; CXR for hilar lymphadenopathy.
• Vogt-Koyanagi-Harada (VKH) Syndrome:
  • Targets melanocytes; HLA-DR4.
  • Phases: Prodromal (flu-like, meningism) → Ophthalmic (bilateral granulomatous panuveitis, multifocal serous RD, disc hyperemia) → Convalescent (sunset glow fundus, vitiligo, poliosis).
• Sympathetic Ophthalmia:
  • Rare bilateral granulomatous panuveitis after penetrating trauma/surgery to one eye (exciting eye).
  • Dalen-Fuchs nodules (epithelioid cells over RPE).
• Birdshot Chorioretinopathy:
  • Chronic, bilateral posterior uveitis; strong HLA-A29 association (>90%).
  • Creamy, ovoid "birdshot" lesions deep, radiating from optic disc; vitritis, vasculitis, CME.

High‑Yield Points - ⚡ Biggest Takeaways

• Toxoplasmosis: Most common infectious posterior uveitis; classic "headlights in fog" appearance.
• CMV retinitis: Affects AIDS patients (CD4 < 50); "pizza pie" or "cottage cheese & ketchup" fundus.
• ARN: Caused by herpes viruses (VZV/HSV); presents with peripheral necrosis, vasculitis, and vitritis.
• Sarcoidosis: Features retinal periphlebitis ("candle wax drippings") and choroidal granulomas.
• Behcet's disease: Associated with HLA-B51; causes occlusive retinal vasculitis and hypopyon.
• Ocular Toxocariasis: Unilateral in children; posterior pole granuloma or peripheral inflammatory mass.