Abstract
Abstract: :
Purpose: To compare the extent and outlines of areas of macular edema identified by stereofundus photography (SFP), Retinal Thickness Analyzer (RTA-Talia Technology, Ltd, Mevaseret, Zion, Israel) and Optical Coherence Tomography (OCT-Humphrey Instruments, Calif. USA) in diabetic eyes diagnosed with clinically significant macular edema (CSME). Methods: Twenty-seven eyes from 19 patients with type 2 diabetes and with a diagnosis of CSME made by SFP using ETDRS guidelines were reexamined within one week with the RTA and OCT, in the same session. The maps of the areas of edema obtained from the SFP, RTA and OCT were superimposed and compared. Areas of increased thickness with the RTA and OCT were identified by using reference maps from healthy control populations within the same age range and considering only values over mean +2SD. Results: Areas of abnormally increased retinal thickness outlined by the RTA showed good correlation with the areas of retinal edema outlined by SFP in 22 of the 27 eyes. The areas outlined by the RTA were larger than the areas outlined using SFT and showed an average maximum % of increase of thickness of 45%. Only in 5 eyes the RTA values remained within normal limits. These eyes presented characteristically small islands of edema around hard exudates on the SFP. Areas of abnormally increased retinal thickness detected by the OCT coincided with the areas of retinal edema outlined by SFP in only 8 of the 27 eyes. Conclusion: The RTA identifies well the areas of retinal edema outlined by SFP and demonstrates that they are larger than recognized on fundus photography. Any disagreements between RTA measurements and SFP outlines are apparently due to the presence of isolated hard exudates. OCT is less reliable to identify mild retinal edema being less sensitive than SFP.
Keywords: 460 macula/fovea • 388 diabetic retinopathy • 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)