Purpose: To correlate the number of inflammatory reactivations in atrophic foci of multifocal choroiditis (MFC) with their growth rate over a 4-year span.
Methods: Comparative case series. Optical coherence tomography scans of patients affected by MFC were reviewed to identify reactivations within or at the margin of atrophic MFC foci. The area of selected lesions was semiautomatically delineated on fundus autofluorescence images and recorded at yearly intervals for a total follow-up of 4 years. The main outcome was the difference in annual square-root transformed area growth rate between lesions that reactivated and lesions that did not.
Results: Sixty-six foci of 30 eyes of 24 patients were included. All MFC foci enlarged over time, but the annual growth rate was more than double in lesions that reactivated compared with those that did not (mean [SD], 0.051 [0.035] vs. 0.021 [0.015] mm/year, P < 0.001), despite starting from comparable baseline areas. For each additional inflammatory reactivation, the annual growth rate increased by more than 20% (+0.009 mm/year, 95% CI [0.006, 0.012], P < 0.001).
Conclusion: Increasing number of reactivations of atrophic foci led to proportional increments in their growth rate, highlighting the need for a tight control of inflammatory relapses in patients affected by MFC.