Vitritis

Inflammatory cells in the vitreous cavity, reflecting inflammation of the retina, choroid, pars plana, or ciliary body, or occasionally primary vitreous disease. It is the key finding in intermediate uveitis and posterior uveitis.

• Causes:
  • Infectious: endophthalmitis (postoperative, endogenous, and post-injection), toxoplasmosis, toxocariasis, cytomegalovirus and herpetic retinitis, candida and other fungi, tuberculosis, syphilis, Lyme disease, bartonellosis, and Whipple disease.
  • Non-infectious: pars planitis (idiopathic intermediate uveitis), sarcoidosis, multiple sclerosis-associated uveitis, Behcet disease, Vogt-Koyanagi-Harada disease, birdshot chorioretinopathy, and inflammatory bowel disease.
  • Masquerade syndromes: primary vitreoretinal lymphoma (central nervous system lymphoma), leukaemia, retinoblastoma (children), and intraocular foreign body.
  • Post-surgical and reactive conditions: retained lens material, retinal detachment, and vitreous haemorrhage.
• Time course and distribution guide diagnosis: acute, painful, with hypopyon suggests bacterial endophthalmitis; chronic, painless, in older patients with a poor response to steroids suggests lymphoma.

• Floaters, blurred vision (haze), and photophobia; pain and redness in anterior involvement or endophthalmitis.
• Vitreous cells and haze (graded by the clarity of the fundus view), "snowballs" (aggregates of inflammatory cells in the inferior vitreous) and "snowbanks" (exudate over the inferior pars plana) in pars planitis, vitreous strands, and precipitates.
• Associated findings: macular oedema, retinal vasculitis, optic disc swelling, retinal or chorioretinal lesions, hypopyon, and posterior synechiae.
• Systemic features: fever and sepsis (endogenous endophthalmitis), neurological symptoms (multiple sclerosis, lymphoma), cough or lymphadenopathy (sarcoidosis, tuberculosis), oral ulcers (Behcet disease), hearing loss and skin changes (Vogt-Koyanagi-Harada), and risk factors for immunosuppression.

• Visual acuity, intraocular pressure, slit lamp with grading of anterior chamber and vitreous cells, dilated fundus examination with scleral depression.
• Optical coherence tomography (macular oedema, epiretinal membrane), fluorescein angiography (vasculitis, leakage), indocyanine green angiography (choroiditis), B-scan ultrasound in dense vitritis, and widefield imaging.
• Blood tests: full count, ESR, CRP, angiotensin-converting enzyme, lysozyme, tuberculosis interferon-gamma release assay, syphilis serology, toxoplasma and toxocara serology, HIV, Lyme serology where relevant, and blood and urine cultures in endogenous endophthalmitis; chest imaging.
• Neuroimaging with contrast and lumbar puncture when lymphoma or multiple sclerosis suspected.
• Diagnostic vitreous biopsy (needle tap or vitrectomy) for suspected infection (culture, polymerase chain reaction) or lymphoma (cytology, flow cytometry, interleukin-10 to interleukin-6 ratio above 1 and MYD88 mutation).

• Infectious vitritis:
  • Bacterial endophthalmitis: urgent vitreous tap with intravitreal vancomycin 1 mg in 0.1 mL and ceftazidime 2.25 mg in 0.1 mL, repeated at 48 to 72 hours as needed; vitrectomy in severe cases with no light perception; topical fortified drugs and cycloplegia; systemic therapy for endogenous cases (intravenous antibiotics for at least 2 weeks).
  • Fungal: intravitreal voriconazole 100 micrograms in 0.1 mL or amphotericin B 5 micrograms in 0.1 mL, with oral voriconazole 400 mg twice daily on day 1 then 200 mg twice daily, and vitrectomy.
  • Toxoplasmosis: pyrimethamine 200 mg loading then 25 to 50 mg daily with sulfadiazine 1 g four times daily and folinic acid 15 mg for 4 to 6 weeks, or trimethoprim-sulfamethoxazole 160/800 mg twice daily, with oral prednisolone 0.5 to 1 mg/kg started after 48 hours of antimicrobials.
  • Viral retinitis: intravenous aciclovir 10 mg/kg every 8 hours (herpes) or ganciclovir 5 mg/kg every 12 hours (cytomegalovirus), with intravitreal injections.
  • Tuberculosis and syphilis: specific antimicrobial treatment with corticosteroid cover.
• Non-infectious vitritis:
  • Periocular triamcinolone acetonide 40 mg (sub-Tenon or orbital floor) every 3 months, or intravitreal triamcinolone 4 mg in 0.1 mL, or dexamethasone implant 0.7 mg, or fluocinolone acetonide implant 0.18 mg for chronic disease.
  • Oral prednisolone 1 mg/kg daily (maximum 60 to 80 mg) tapered over 6 to 8 weeks.
  • Steroid-sparing therapy for chronic or recurrent disease: methotrexate 15 to 25 mg weekly with folic acid 5 mg weekly, azathioprine 2 mg/kg daily, mycophenolate 1 g twice daily, ciclosporin 3 to 5 mg/kg daily, adalimumab 80 mg loading then 40 mg every 2 weeks.
  • Cystoid macular oedema: topical or periocular steroid, topical NSAID, acetazolamide 250 mg twice daily.
  • Vitrectomy for persistent opacities, tractional or epiretinal membranes, and diagnostic needs.
• Primary vitreoretinal lymphoma: intravitreal methotrexate 400 micrograms in 0.1 mL (weekly for 4 weeks, then twice monthly for 8, then monthly for 9), combined with systemic high-dose methotrexate (3.5 to 8 g/m2 every 2 weeks with leucovorin rescue) and radiotherapy or autologous stem cell transplant, managed by oncology.
• Monitor intraocular pressure and cataract in steroid users; follow every 4 to 12 weeks.