OCT- A Characteristics of Neovascular Membranes in Wet AMD- Possible Correlation to the Prognosis.

OCT-A i a new imaging modality that provides the opportunity for noninvasive characterization and quantification of the microvasculature in wet AMD. Purpose: The purpose of our study is to outline the different OCT- A characteristics of neovascular membranes in AMD in regard to their correlation with the effect of treatment and prognosis. Methods: : In our prospective study 42 patients with wet AMD were enrolled. They were divided in 3 groups: 25 with Type 1 membranes (under RPE), 11 patients with Type 2 membranes and 6 with Type 3 – RAP lesions. They all underwent a complete ophthalmological examination including VA, fundus photography, structural OCT (Rtvue, Optovue) and OCT-A (Angiophlex, Zeiss). All of the patients were treated with aflibercept (Eylea) - 3 injections. They all were evaluated after the third injection. Results: : In the group of patients with type 1 CNV usually a medusa shaped neovascular complex with afferent vessel, originating in the choroid was observed on the OCT-A. In 9 cases the vessels were very rough and larger than in the general group. The type 2 CNV we visualized a neovascular network that grows from the choroid vasculature traverses the RPE- Bruch’s membrane complex into the subretinal space. These structures usually had glomeruli like shape. Type 3 CNV is seen on OCT-A as retinal-choroid anastomoses originating in the deep capillary plexus of the retina. The majority of patients improved VA and retinal thickness after the application of Eylea. Only in 9 cases no change was seen. Those were mainly cases with Type 1 CNV and with larger caliber of the vessels. Conclusion: OCT angiography is a new imaging modality capable of revealing the morphological structure of Type 1, Type 2, and Type 3 neovascularization in exudative AMD. Visualizing the microarchitecture of the CNV membrane offers the prospect to evaluate the possible responses to therapy. Our results indicate that type 1 lesions, composed of a greater proportion of larger, mature vessels are less responsive to anti-VEGF therapy and are with poor prognosis.