Purpose:
To investigate the role of indocyanine green angiography (ICGA) for the detection of macular "treatable lesions" in patients with diabetic retinopathy and associated maculopathy.
Methods:
This was a retrospective study including patients with diabetic retinopathy and at least one macular "treatable lesion" on fluorescein angiography (FA) as per Early Treatment Diabetic Retinopathy Study (ETDRS) guidelines (points of retinal hyperfluorescence or leakage ≥500 µm from the center of the macula, areas of diffuse leakage within the retina, and retinal avascular zones) consecutively evaluated at a single retinal center. Stereoscopic angiographic studies using both fluorescein and indocyanine green at the same visit was available for all patients. The angiographic characteristics of the macular region on ICGA were studied.
Results:
A total of 14 patients (28 eyes) were included in the study. All patients had diabetic retinopathy (ranging from mild non-proliferative to high-risk proliferative disease) and at least one macular "treatable lesion" identified on FA. The "points" of retinal hyperfluorescence on FA correlated well with overt circular formations with increased uptake of indocyanine green on ICGA, with the identification of these "points" relatively easier on ICGA. Areas of diffuse leakage on FA presented a somewhat different angiographic picture on ICGA, with larger areas of hyperfluorescence identified on FA than on ICGA. Retinal avascular zones were more likely to be identified on FA than on ICGA, as long as no media opacities were present. In general, no dye leakage was observed on ICGA, even in eyes with diffuse macular edema.
Conclusions:
The detection of ETDRS macular treatable lesions in patients with diabetic retinopathy was feasible on ICGA. The absence of indocyanine green leakage in eyes with diffuse macular edema on FA and the fact that identification of points of retinal hyperfluorescence on FA was facilitated on ICGA, particularly within areas of diffuse retinal leakage, suggest that ICGA may be an interesting tool to assist the strategic planning of macular (focal) laser photocoagulation.
Keywords: diabetic retinopathy • edema • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)