ICGA fluorescence can penetrate blood, fluid and retinal pigment epithelium to reveal underlying abnormalities of the inner choroidal vasculature and is essential for making a definitive diagnosis of PCV. | Extremely motion sensitive, requiring a patient to fixate on precise point for several seconds. Patient compliance required, which is often difficult, particularly for older patients. |
Excellent visualisation within minutes, of the medium & large choroidal vessels. | OCTA takes more time than structural scans and requires trade-offs in flow resolution, scan quality and speed. |
ICGA is beneficial in the differential diagnosis of PCV, Chronic CSC, and RAP. | Limited field of view leading to a greater likelihood that lesions may be missed. |
ICGA has been shown to optimise detection of capillary macro aneurysms in longstanding diabetic macular edema (DME) or retinal vein occlusion (RVO). | Failure to recognise OCTA Projection Artifact (blood vessels seem at erroneous location), may lead to inaccurate clinical assessment. |
A recent study demonstrated that late leakage in ICGA occurred in all RAP cases*. | Image processing for OCTA can alter blood vessel appearance through egmentation defects, and image display software can lead to false impressions of vessel location and density |
Duration of ICGA procedure only 15 20mins, very quick analysis. | The analysis of these images is time-consuming – may involve many hours of post hoc manual segmentation work, which may be difficult to accommodate during daily medical work routines. |