Abstract
Purpose:
While the presence of classic lesions seen on indocyanine green angiography (ICG) has been well described in the diagnosis of birdshot retinochoroidopathy, limited information exists on the natural history of these lesions, with or without treatment. This is a retrospective case series that objectively describes the evolution of these lesions between times of disease activity and quiescence.
Methods:
A retrospective review was performed on all patients with birdshot retinochoroidopathy who had at least one ICG performed during disease activity and disease quiescence. For each patient, a single photograph of a single eye centered on the posterior pole during the intermediate phase (~10min) of the ICG was selected for analysis during time of disease activity and quiescence. Photoshop was used to mark the lesions. The mean total number of spots and total lesional area was compared between disease activity and quiescence using a paired ratio t-test.
Results:
A total of 26 patients (26 eyes) were analyzed. There was a mean of 75.27 total spots encompassing a mean total area of 24,525.42 pixels during disease activity. There was a mean of 28.35 total spots encompassing a mean total area of 7,411.00 pixels during disease quiescence. There was a statistically significant decrease in both the mean total number of spots (-62.34%, p<0.01) and total lesion area (-69.78%, p<0.01) between disease activity and quiescence. In 24 patients, resolution of spots correlated with treatment-induced disease quiescence. In 2 patients with a relative absence of ICG spots during treatment-induced remission, subsequent reappearance of spots correlated with a flare of disease activity.
Conclusions:
There was a statistically significant decrease in the mean number of lesions and lesion area between time of disease activity and disease quiescence. Our results suggest that ICG has a role not only in diagnosis, but also in monitoring treatment effectiveness. ICG lesions can resolve with treatment, and their reappearance may be indicator of disease relapse.