MUST study conclusions should rely on 2-year, not 7-year, findings

This editorial reexamines the findings of the National Eye Institute-sponsored Multicenter Uveitis Steroid Treatment study. The authors also present evidence-based guidance for the treatment of noninfectious posterior segment-involving uveitis.

Study design

In the Multicenter Uveitis Steroid Treatment (MUST) study, patients with severe, non-infectious intermediate, posterior or panuveitis were randomized to receive the intravitreal fluocinolone acetonide implant (Retisert) or systemic steroid-sparing therapy. The primary outcome was visual acuity (VA) at 2 years. However, investigators continued to enroll patients for more than 7 years and published a follow-up study, which concluded that systemic treatment is safer and more effective than the implant. The present editorial casts doubt on the 7-year findings due concerns regarding the study design.

Outcomes

At 7 years, systemic therapy appeared more effective than Retisert. However, 75% of eyes in the Retisert arm had a single 3-year implant and a minority of eyes in this arm were reimplanted beyond year 3. Unfortunately, the observational MUST study cannot determine how these eyes might have fared had they received regular, scheduled care to maintain functioning implants. Therefore, the study’s conclusions should rely on the 2-year follow-up data.

Limitations

This is a review of published data, which limits the amount of information that can be gleaned. 

Clinical significance

The 7-year data suggest that systemic therapy is superior to the surgically-placed fluocinolone implant; however, these results should be interpreted with caution due to the potential side-effects of systemic therapy, a patient’s potential desire for pregnancy, patient prejudice against systemic therapy, the complexity and number of systemic agents required to control a particular patient's ocular inflammation and the low rate of re-implantation in the study’s surgical arm.