Indocyanine green angiographic findings in nonproliferative diabetic retinopathy

To report angiographic findings of nonproliferative diabetic retinopathy patients by means of indocyanine green angiography.

Forty-two eyes (42 patients) with nonproliferative diabetic retinopathy were evaluated by indocyanine green angiography in addition to fluorescein angiography. Angiographic findings with the two imaging techniques were compared with the red-free fundus appearance.

Among the 42 eyes, five (12%) had the appearance on indocyanine green angiography of lobular spotty hyperfluorescent and hypofluorescent areas ("salt and pepper" appearance) in the very late phase. Twenty eyes (48%) presented with diffuse late-phase hyperfluorescence on indocyanine green angiography, corresponding to areas of retinal capillary nonperfusion on fluorescein angiography, and retinal edema. A total of 3,564 microaneurysms were divided into three types: 58 (1.6%) appeared mainly on the fluorescein angiography and very faintly on the indocyanine green angiography, 3,029 (85%) appeared on the fluorescein angiography and the indocyanine green angiography, and 477 (13.4%) were uniquely hyperfluorescent on the indocyanine green angiography.

Indocyanine green angiography in patients with nonproliferative diabetic retinopathy disclosed microvascular findings that were in addition to those shown on fluorescein angiography. These angiographic changes were not observed on fluorescein angiography because of imaging limitations. Indocyanine green angiography may be a useful adjunct to fluorescein angiography in the evaluation of chorioretinal vascular changes in nonproliferative diabetic retinopathy.