Optical coherence tomography angiography (OCT-A) is an informative method for identifying and evaluating the vascular network of small choroidal melanomas (CM). It is also valuable for monitoring tumor regression and vascular changes after radiation therapy. However, there is only a limited number of studies specifically focused on treated CM.

PURPOSE

This study aimed to determine OCT-A signs associated with different outcomes of eye-preserving treatment.

MATERIAL AND METHODS

OCT-A was performed in 12 patients (12 eyes) after eye-preserving treatment for CM. At the time of examination, the mean follow-up period after treatment was 66 months (ranging from 4 to 374 months). Six patients were examined after brachytherapy, three — after transpupillary thermotherapy, two — after destructive laser photocoagulation, and one — after stereotactic radiosurgery. Image analysis was performed using customized segmentation to improve the accuracy of data interpretation.

RESULTS

Large straight vessels were identified in the areas of chorioretinal scars, and at the border between scars and preserved retina there were looped vessels (loss of terminal capillaries with formation of loops). No vascular signal was detected in areas of pigment hyperplasia. Numerous thin vessels forming anastomoses with retinal vessels were observed in regions of residual tumor. Vascular network including arches and arcs appeared in cases of continued tumor growth. Dense vascular networks without a distinct pattern or anastomoses with retinal vessels were detected in areas of reaction to radiation.

CONCLUSION

OCT-A is a valuable method for monitoring tumor regression and vascular changes after radiation therapy, but accurate interpretation of its data requires careful customized segmentation. Large-caliber linear vessels should be differentiated from projection artifacts. Moderate tortuosity and large atypical choroidal vessels may represent compensatory remodeling of the vascular bed.