Diagnosis → Ophthalmology

Retinitis

Etiology

Cause [ea3][gmn]

• Virus:

  • Herpes simplex virus

  • Varicella zoster virus

  • Cytomegalovirus (immunocompromised individuals)

  • Epstein-Barr virus

  • West Nile virus

  • HIV

  • Rubella

  • Measles

  • Dengue virus

  • Lymphocytic choriomeningitis virus

  • Chikungunya virus

• Bacteria:

  • Syphilis

  • Tuberculosis

  • Cat scratch disease (Bartonella henselae)

  • Rocky Mountain spotted fever (Rickettsia rickettsii)

  • Lyme disease (Borrelia burgdorferi)

  • Histoplasmosis (Histoplasma capsulatum)

  • Endophthalmitis (S. aureus and S. pneumoniae, Klebsiella pneumoniae)

  • Hematogenous dissemination: Endocarditis, gastroenteritis, UTI, IV drugs

•  Fungal disease:

  • Aspergillus

  • Candida

• Parasite: Toxoplasma gondii

• Helminthic disease: Toxocara canis

• Inflammatory disease:

  • Post-fever retinitis

  • Behçet disease

  • Sarcoidosis

  • Systemic lupus erythematosus

  • Eosinophilic granulomatosis with polyangiitis

  • Psoriatic arthritis

  • Inflammatory bowel disease

  • Sjögren syndrome

  • Vogt-Koyanagi-Harada syndrome

• Hypersensitivity reactions

Pathophysiology [ea3]

1. Intraocular inflammation due to:

   • Hematogenous dissemination of pathogens

   • Direct introduction

   • Autoimmunity (molecular mimicry due to cross-reactivity)

2. The extent of ocular involvement varies depending on the organism/etiology [gmn]

3. Inflammation --> visual changes:

   • Macular edema

   • Neovascularization of the retina or optic disc

   • Optic disc swelling

   • Epiretinal membrane detachment

   • Retinal detachment

4. Permanent changes:

   • Macular ischemia

   • Optic nerve atrophy

   • Retinal necrosis and scarring

Risk factors [ea3]

• HLA-B27

• Immunosuppression

Complication [ea3][gmn]

• Blindness

• Retinal breaks

• Rhegmatogenous retinal detachment

• Optic neuropathy

• Optic atrophy

• Macular scar

• Epiretinal membrane/vitreomacular traction

• Cystoid macular edema

• Choroidal neovascularization

• Cataract

• Chronic vitritis

• Macular ischemia

• Retinal vascular occlusion

• Glaucoma

• Vitreous hemorrhage

• Phthisis

Epidemiology

Incidence per 100.000 [ydi][p7z]

Default

Approach

• Ophthalmologic examination: [ea3]

  • Visual field assessment

  • Slit-lamp examination

  • Funduscopic photos

  • Fluorescein fundus angiography

  • Optical coherence tomography

• Ultrasound: To exclude retinal detachment

• Aqueous or vitreous humor tests:

  • Microbial culture: Bacterial, fungal, and viral

  • Staining tests: KOH and gram staining of the aqueous or vitreous humor

  • PCR for bacteria, fungi, Toxoplasma, HSV, HZV, and CMV

  • IGRA

• Serelogy (ELISA) for anti-Toxoplasma IgG antibodies

• Biopsy of the retina

Treatment

1. Topical medications exhibit limited effectiveness against posterior uveitis [ea3]

2. Autoimmune retinitis:

   • Periocular or intraocular glucocorticoid injections

   • Systemic glucocorticoids if severe or bilateral disease

   • Injected or surgically implanted intraocular long-acting glucocorticoid

   • Immunosuppressive agents if glucocorticoid resistance

     • Methotrexate, azathioprine, mycophenolate mofetil, cyclosporine, tacrolimus, TNF-α inhibitors

3. CMV retinitis:

   • Ganciclovir (IV and intravitreal): 5 mg/kg every 12 hours for 14 to 21 days

   • Foscarnet

   • Cidofovir (IV)

   • Valganciclovir (oral): 900 mg twice daily

4. Herpes retinitis:

   • Acyclovir (IV) 10 to 15 mg/kg every 8 hours

   • Acyclovir (oral) 800 mg 5 times a day for 6 to 12 weeks

5. Toxoplasmosis:

   • Trimethoprim-sulfamethoxazole 160 mg/800 mg twice daily

   • Clindamycin (intravitreal)

6. Toxocariasis:

   • Systemic and topical steroids

   • Anthelmintic drugs: Albendazole 400 mg twice daily for 2 weeks

   • Pars plana vitrectomy

7. Syphilis: Penicillin G 4 million units every 4 hours

8. Lyme disease: Doxycycline, ceftriaxone, and amoxicillin

9. Cat Scratch Disease:

   • Age ≥8 years: Doxycycline and rifampin

   • Age <8 years: Rifampin + azithromycin or TMP-SMX

10. Sarcoidosis: Glucocorticoids 1-1.5 mg/kg/d

    • Options: Methotrexate, mycophenolate mofetil, azathioprine, cyclosporine, adalimumab

11. Rocky Mountain Spotted Fever: Doxycycline or chloramphenicol

Differential diagnoses

Age-related macular degeneration, Behcet's disease, Candidiasis, Crohn disease, Drug side effects, Endophthalmitis, Histoplasmosis, Iridocyclitis, Lymphoma, Malignant melanoma, Multiple sclerosis, Optic neuritis, Reactive arthritis, Retinal detachment, Retinoblastoma, Scleritis, Systemic lupus erythematosus, Toxoplasmosis, Tuberculosis, Ulcerative colitis, Vogt-Koyanagi-Harada syndrome