Abstract
Purpose :
To determine the feasibility of using en face OCT images to reliably delineate choroidal lesion boundary and measure total choroidal lesion area.
Methods :
Pigmented and amelanotic lesions of the choroid were imaged with a PLEX Elite 9000 SS-OCTA device. The full thickness choroidal en-face image was generated using the minimum projection of the region between the RPE/BM complex and the choroidal-scleral interface. Lesion boundaries were defined by a masked human grader and lesion area calculated in MATLAB. Clinical determination of en face lesion area was made by the treating physician on color fundus images or at the time of dilated exam and recorded in disc diameters. Clinical ultrasound measurements of maximal transverse and longitudinal base diameter were used to calculate the en face lesion area using the formula for an elipse. Agreement in lesion area determined by each method was evaluated by intraclass correlation coefficient (ICC).
Results :
Seventeen lesions were imaged by OCT: 8 choroidal melanomas, 4 choroidal nevi, 5 choroidal hemangiomas. In the en-face image, all lesions appeared as homogeneous white regions without characteristic pattern of large choroidal vessels. 3 lesions had borders extending beyond the SS-OCT image window and were not included in area analysis. The agreement between OCT and fundus exam area was poor (ICC=0.03). The agreement between US and fundus exam was moderate (ICC =0.51). The agreement between US and OCT on the 4 lesions with same day imaging was excellent (ICC=0.99). Three lesions with mixed pigmentary components measured much smaller by fundus exam than by OCT or US.
Conclusions :
Pigmented and amelanotic fundus lesions can be identified in the SS-OCT choroidal en face projection. The resulting image provides a new method for lesion area measurement with excellent agreement to US measurements and could be useful for longitudinal monitoring. Larger studies with same day exam, SS-OCT, and ultrasound measurements will be required to verify the extent of agreement suggested by this pilot study.
This is a 2021 ARVO Annual Meeting abstract.