Steroid Dosing for Iris Involvement in Tuberculosis
For tubercular iris involvement (ocular TB-IRIS), prednisone should be given at a dose of 1.25 mg/kg/day (approximately 50-80 mg/day) for 2-4 weeks, with gradual tapering over 6-12 weeks or longer. 1
Understanding TB-IRIS and Ocular Involvement
Immune Reconstitution Inflammatory Syndrome (IRIS) can occur in tuberculosis patients, particularly when:
- Starting anti-retroviral therapy (ART) in HIV co-infected patients 1
- Beginning anti-tubercular therapy (ATT) 2
- Ocular manifestations may include anterior uveitis, intermediate uveitis, retinal vasculitis, and choroidal involvement 3
Steroid Treatment Protocol
Initial Dosing
- Severe IRIS: Prednisone 1.25 mg/kg/day (50-80 mg/day) 1
- Mild IRIS: Anti-inflammatory agents such as ibuprofen may be sufficient 1
Duration and Tapering
- Initial high-dose treatment: 2-4 weeks 1
- Tapering period: 6-12 weeks or longer, depending on clinical response 1
- Monitor for resolution of inflammation during tapering 2
Special Considerations
- For tuberculous meningitis or CNS tuberculosis, avoid early initiation of ART (within first 8 weeks) due to increased risk of severe IRIS 1
- Patients with choroidal involvement or vitreous haze may require longer or more aggressive steroid treatment 3
Monitoring and Management
Response Assessment
- Monitor for resolution of ocular inflammation 2
- Assess ability to taper steroids to <10 mg/day without inflammatory progression 3
- Evaluate visual acuity improvement 4
Treatment Failure Signs
- Persistence or recurrence of inflammation within 6 months of completing ATT 3
- Inability to taper oral corticosteroids to less than 10 mg/day 3
- Recalcitrant inflammation requiring immunosuppressive therapy 3
Additional Therapeutic Considerations
Concurrent Anti-Tubercular Therapy
- Continue ATT alongside steroid treatment 4
- Complete ATT course of >9 months reduces recurrence risk 11-fold 5
Refractory Cases
- Progressive inflammation despite ATT occurs in approximately 24.5% of cases 2
- Most (61.5%) resolve with escalation of corticosteroid therapy 2
- Some cases may require therapeutic procedures (e.g., vitrectomy) 2
- Consider intravitreal anti-VEGF agents (bevacizumab) for serous retinal detachment unresponsive to steroids 6
Pitfalls and Caveats
- Ensure TB diagnosis is confirmed before starting steroids, as they can worsen untreated TB 1
- Rule out other causes of ocular inflammation before attributing to TB-IRIS 2
- Be vigilant for steroid-related complications such as cataracts and glaucoma 1
- Consider prophylactic treatment for steroid-induced complications in prolonged therapy 1
- Recognize that treatment failure in TB uveitis is relatively low (12.7%) when appropriate ATT and steroids are used 3