Knobby-like choroidal neovascularization accompanied with retinal pigment epithelial detachment

Objective: To evaluate the clinical features of knobby choroidal neovascularization (CNV) which was detected using indocyanine green (ICG) angiography and the association between knobby CNV and idiopathic polypoidal choroidal vasculopathy (IPCV).

Methods: We studied 164 eyes with retinal pigment epithelial detachment (PED) accompanied with CNV. These patients were older than 50 years. We detected knobby CNV in 96 eyes of 164 PED eyes (58.5%). Knobby CNV was defined as follows: knobbed blood vessels were observed from the early phase and remained hyperfluorescent through the ICG angiography. We classified 3 groups on the basis of the types of vessels with knobby CNV: group I, multiple isolated knobby CNVs without continuous vessels (24 eyes); group II, knobby dilatations in some parts of CNV (45 eyes); group III, network vessels ending in multiple aneurysmal swelling as in IPCV (27 eyes).

Results: We found knobby CNV in only 20% of eyes with serous PED, but about 70% in neovascular, serosanguineous, and hemorrhagic PED. The ratio of each group showed no distinction statistically. Knobby CNV mostly appeared in macular areas, and was frequently accompanied with subretinal or subpigment epithelial hemorrhage. Subretinal reddishorange lesions were seen in 50% of group I, 60% of group II, and 89% of group III. Knobby CNV showed occult CNV in fluorescein angiography. In late phase ICG angiography, knobby CNV leaked ICG. New lesions occurred in all groups.

Conclusions: We think that knobby CNV is a common finding in subpigment epithelial neovascularization, and that IPCV vascular lesion is one type of subpigment epithelial neovascularization.