Abstract
Purpose :
Choroidal lesions can be seen on enhanced depth imaging optical coherence tomography (EDI-OCT) of individuals with birdshot chorioretinitis (BSCR). Some clinicians have assumed that these choroidal lesions are the “birdshot (BS) lesions” seen on clinical exam. Studies have shown that choroidal lesions identified by EDI-OCT are related to certain features of BSCR, including vitreous inflammatory reactions and macular edema, while other studies have shown that the clinical characteristics of BS lesions are not related to the same disease features. We sought to determine whether there is a relationship between BS lesions seen on fundus photographs and choroidal lesions seen on EDI-OCT.
Methods :
Using co-localization techniques, we compared BS lesions on color fundus photographs to choroidal lesions identified on EDI-OCT (Heidelberg Spectralis) of four eyes (two individuals) with BSCR. A choroidal lesion was defined as a homogenous hyporeflectivity that was present external to the Bruch membrane and internal to the choroidal-scleral border. Two investigators (GNH, ET) agreed on the borders of three random BS lesions for each eye, and outlined the lesions on the color photographs with ImageJ software. Three B-scans, equidistant from the borders of the BS lesions and from each other, were identified and evaluated by a third investigator (ARS) for underlying choroidal lesions. If choroidal lesions were present, the width of BS lesions and the width of underlying choroidal lesions were compared.
Results :
Only 10 (83.3%) of 12 BS lesions had underlying choroidal lesions on one or more of the three scans. For only six (60%) of these 10 BS lesions were choroidal lesions identified on all three scans; choroidal lesions were identified on two of three scans for two lesions, and on one of three scans for two lesions. On all 24 EDI-OCT images with choroidal lesions, the width of the choroidal lesion was greater than the width of the overlying BS lesion on fundus photographs.
Conclusions :
Clinically apparent BS lesions are not precise representations of choroidal lesions on EDI-OCT images. EDI-OCT may provide information for evaluation and monitoring of BSCR that cannot be derived from clinical examination alone. Study of additional lesion characteristics may identify how BS lesions are related to choroidal findings on EDI-OCT, if at all.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.