Abstract
Purpose :
Choroidal neovascularization (CNV) evolution after treatment is an important problem in AMD patients follow up. Fluorescein angiography (FA) or indocyanine green angiography (ICG) show the indirect signs of CNV activity not allowing the
CNV features. A new tool to evaluate retinal circulation by dyeless method has been introduced.The new method has been defined as optical coherence tomography–angiography (OCT-A).
The aim of our study is to assess by video the longitudinal development of CNV Type 2 after intravitreal anti–vascular endothelial growth factor by OCT-A. With OCTA images we created videos that show the evolution and highlight interesting feature about recurrences and dark area around CNV.
Methods :
5 eyes with naive CNV Type 2 were assessed by OCT-A in this observational longitudinal study. To perform the OCT-A we used SSADA algorithm. OCTA frames were taken at 24 hours after injection, between 7 days and 10 days, between 12 days and 18 days, and 30 days after the intravitreal anti–vascular endothelial growth factor injections. A simple animation was made by power point transition tool. image alignment was made by overlaying superficial vessels crossings. The stack shows the last examination on the top followed by the other examinations down below. The transition consist in the fading of the upper image on the next. The day after the injection, OCT-A showed significant decrease of neovascularization flow and dimension. The CNV area was fragmented with pruning of thinner anastomoses and loss of smaller vessels. Decrease of dimensions of CNV area, microvascular rarefaction, and vessels narrowing was observed between 7 days and 10 days, and between 12 days and 18 days with further loss of smaller capillaries. Residual flow was always visible to the afferent trunk over the time.
Results :
The most salient result emerging from this study is the consistency in the patterns of cyclic CNV variations after treatment in different patients, and the capillary irregularity in recurrence appearance.
Conclusions :
OCT-A video allows a precise follow up of Type 2 CNV developments with noninvasive analysis of CNV networks remodeling after treatment and more precise recurrence assessment. In conclusion, OCTA videos highlight interesting feature about recurrences and dark area around CNV during treated evolution providing a useful approach for monitoring the CNV Type 2 over time.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.