Vasoproliferative retinal tumor treated with indocyanine green-mediated photothrombosis

To assess the efficacy of indocyanine green-mediated photothrombosis (ICGMP) in the treatment of large vascular lesions, and in particular of a 6-mm large, actively exudating vasoproliferative retinal tumor (VPRT).

Thirty minutes after the administration of a loading dose of 1 mg/kg of intravenous ICG multiple, confluent, 2 mm wide, infrared 810 nm diode laser spots were applied on the surface of the tumor. Duration of each spot was 60 seconds, and the power chosen was 400 mW. A subTenon injection of 40 mg triamcinolone suspension was administered immediately after treatment.

No change in tumor aspect was observed after treatment. ICG late images were taken, showing no perfusion of the lesion. Two weeks after treatment the lesion was remarkably reduced in volume, but residual perfusion on ICG was observed. A second treatment with three laser spots on the diffusion site under the same modalities was performed. After the second treatment a complete obliteration of the lesion could be observed. In the original tumor site patchy retinal pigment epithelium atrophy and hyperplasia appeared. A diffuse, gradual, complete resolution of the exudates is now apparent at the fundus. Vision has slightly improved to 20/100. Follow-up has reached 2 years.

In the presented case ICGMP achieved complete obliteration of a large VPRT. To our knowledge, this is the first VPRT successfully treated with ICGMP, and the largest retinal vascular lesion treated with laser technique reported in the literature. ICGMP is less invasive than cryotherapy and less expensive than recently proposed photodynamic therapy. It may deserve further study in the treatment of selected retinal vascular tumors.