Abstract
Purpose :
To evaluate the effects of anti-VEGF treatment in retinal extracellular fluid in Diabetic Macular Edema (DME) patients by using OCT-Leakage (OCT-L), a new method of analysis and mapping sites of lower optical reflectivity found in optical coherence tomography angiography (OCT-A), and to correlate these findings with retinal thickness (RT) changes.
Methods :
Prospective analysis of 12 eyes with DME, naïve to anti-VEGF treatment. Macular Cube 512x128 OCT scans and Angiography 6x6mm OCT-A scans (CIRRUS AngioPlex (ZEISS, Dublin,California,USA) were acquired in all eyes before the first anti-VEGF injection (V1) and 1 week after treatment (V2). OCT-L analysis was performed with Angioplex raw scan data used to calculate lower than normal optical reflectivity maps (LOR ratios). Optical reflectivity LOR maps (OCT-L maps) were collected for full retina A-Scan and layer by layer after segmentation in order to evaluate which layers have more fluid accumulation. To evaluate anti-VEGF treatment effects on each retina layers, LOR ratios from V1 and V2 were compared. Standard OCT scans were performed in all eyes to evaluate RT differences between visits and to correlate RT with LOR.
Results :
A significant RT decrease was observed after 1 week of treatment (-80.08µm± 87.07µm) in the central subfield. The OCT-L maps based on sites of lower optical reflectivity (LOR ratios) delineated the location of intraretinal and subretinal fluid and showed the areas of larger quantities of fluid. At baseline, these were located in the Outer Nuclear Layer+Inner Segments complex (ONL+IS), in Outer Segments Layer (OS) and in Inner Nuclear Layer (INL) with LOR ratios of 0.39±0.3; 0.19±0.3 and 0.11±0.08; respectively. A significant LOR ratios decrease was found after anti-VEGF treatment in all layers, especially in ONL+IS and INL (-0.13;p=0.034 and -0,05;p=0,009,respectively). LOR ratio changes after treatment were strongly correlated with thickness changes (r2= 0.839;p<0.001) and showed a wide range of values (0.1-0.96) demonstrating well the individual response to treatment. The fluid areas outlined in OCT-L maps were coincident with layers with greater thickness changes in OCT-A.
Conclusions :
Mapping of lower reflectivity sites within the retina was able to identify the amount and preferential location of retinal and subretinal fluid accumulation in DME and can be used in DME treatment management with anti-VEGF.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.