Novel optical coherence tomography angiography findings of retinal-choroidal anastomosis in macular neovascularization type 3
Author: Bilal Haj Najeeb (Austria)
Co-authors: Stefan Sacu, Ursula Schmidt-Erfurth
To describe the course of retinal-choroidal anastomosis (RCA) and the state of the choroidal perfusion in the central macula (3x3 mm) in patients with macular neovascularization type 3 (MNV3) using optical coherence tomography angiography (OCTA).
5 RCA in 4 eyes of 2 patients with MNV3 were included.
Multimodal imaging including wide field color photography, fluorescein and indocyanine angiography and OCTA (Plex Elite 9000 Carl Zeiss Meditec Inc., Dublin, USA) was used to explore the course of 5 RCA in 4 eyes of 2 patients with MNV3.
Patient 1: A 78 years female with bilateral MNV3 and a history of anti-angiogenic therapy. The right eye illustrated a central fibrosis and an enlarged temporal inferior retinal arteriole turning deep in the central macula on clinical examination. OCTA revealed the hidden route of the arteriole where it continued through the fibrotic tissue and bifurcated to many branches in the choroid. The left eye showed a similar picture of a temporal inferior arteriole making a big retrograde loop within the fibrotic tissue before it communicated with a small choroidal vessel superior to the fovea. Patient 2: A 75 years female with bilateral lamellar hole secondary to untreated cystoid macular edema by MNV3. OCTA of the right eye showed enlarged temporal superior venule and temporal inferior arteriole running through the subretinal scar tissue and turning around the fovea to the nasal inferior and nasal superior macular quadrants, respectively. In the left eye a superior temporal venule making many loops within the fibrotic tissue was identified. In all 4 eyes a loss of vessels in all three choroidal layers and absence of ascending choroidal vessels within the fibrotic tissue were observed on the choroidal slab of OCTA.
RCA is associated with fibrosis and choroidal ischemia in the central macula. The subretinal downgrowth of the retinal vessels occurs through the fibrotic tissue only. The retinal vessels tend to make a long route through the fibrotic tissue before they extend into the choroid. Furthermore, the development of RCA is not related to anti-angiogenic therapy.