Abstract
Purpose:
To identify signs occurring more frequently in RAP lesions compared to other types of choroidal neovascularization (CNV) whose combination might facilitate a proper diagnosis of RAP
Methods:
30 patients with active neovascular lesions (classic-type 1, occult-type 2 and RAP-type 3 CNVs) were evaluated independently by two different observers, using a multimodal imaging approach: infrared light (IR), optical coherence tomography (OCT), fluorescein angiography (FA), indocyanine green angiography (ICGA). The signs evaluated were the following: shunting of blood flow to the RAP (feeding retinal vessel larger than the surrounding perifoveal vessels), late leakage in ICGA, intraretinal cysts in OCT, RPE interruption along the pigment epithelial detachment (PED) (with hyper-reflective oval area) in OCT, “hot spot” in FA and ICGA always located within the edges of the PED, and presence of reticular pseudodrusen. Agreement between the two observers was evaluated using Cohen’s k statistics
Results:
Shunting of blood flow, shown by feeding retinal vessel larger than the surrounding perifoveal vessels, was found in 56% of cases of RAP whereas it was absent in 100% of cases of other CNV types. Late leakage in ICGA occurred in all cases of RAP; by contrast, it was found in only 7% of cases of type 1 or 2 CNV. In OCT, intraretinal cysts were detected in 100% of cases of RAP and in 21% of cases of type 1-2 CNV. RPE interruption along the RPE detachment was evident in 88% of cases of RAP and in 29% of type 1-2 CNV. “Hot spots” in FA and ICGA within the edges of PED were detected in all cases of RAP and in only 14% of type 1-2 CNV. Reticular pseudodrusen, detected in the study or the fellow eye, were present in 87% of cases of RAP and in 21% of type 1-2 CNV
Conclusions:
The previous findings show that all the signs investigated are strongly associated with the presence of RAP lesions. Evidence of late leakage in ICGA, intraretinal cysts and the “hot spot” in FA and ICGA within the edges of PED are particularly significant. A multimodal imaging approach may be of great help for diagnosing the different subtypes of neovascularization
Keywords: 412 age-related macular degeneration •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
700 retinal neovascularization