Abstract
Purpose: :
To report the blue-light fundus autofluorescence (bAF) findings in patients with the classic clinical presentation of ocular toxoplasmosis (OT)
Methods: :
Twenty-four patients with OT, including an active focus of retinochoroiditis adjacent to a pigmented chorioretinal scar (satellite lesion), underwent standardized ophthalmologic examination and multimodal fundus imaging. The bAF findings observed at presentation and during a 24-week follow-up period are described.
Results: :
The mean age of the fourteen (58.3%) women and ten (41.7%) men was 27.6 years (range, 10-59 years). The mean logMAR ETDRS best-corrected visual acuity was 0.58 (Snellen equivalent, 20/80+1). The diagnosis and baseline evaluation were performed within 7 days of the onset of symptoms. At baseline, a poorly defined area of amorphous fluorescence was observed in the fundus region encompassing the active OT lesion; within this area, a smaller area of increased fluorescence was also observed in 14 (58%) cases (Stage I). Between weeks 2 and 7 (median 4 weeks), there was an obvious decrease in the area of amorphous fluorescence encompassing the active OT lesion, and a sharply demarcated rim-shaped area of hypoautofluorescence was observed adjacent to a well-defined round area of hyperautofluorescence in the center (Stage II). Between weeks 4 and 21 (median, 10 weeks), the rim-shaped hypoautofluorescent area tended to progress in a centripetal fashion (Stage III), until complete disappearance of the adjacent central hyperautofluorescent region was noted between weeks 14 and 55 (median 28 weeks) (Stage IV).
Conclusions: :
A well-defined sequence of changes on bAF was identified in patients with an active OT lesion. The identification of a hypoautofluorescent rim adjacent to the lesion was suggestive that the healing process had been initiated. Centripetal progression of the hypoautofluorescent rim was subsequently observed, until complete absence of fluorescence on bAF was observed in clinically healed lesions. Findings of the current study suggest that bAF may be a helpful tool for monitoring the inflammatory process associated with OT.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • toxoplasmosis • uveitis-clinical/animal model