Abstract
Abstract: :
Purpose:Until now the judgment of diabetic maculopathy is made by biomicroscopy and fluorescence angiography. New techniques allow a quantitative assessment of the central retinal thickness. This study was undertaken to compare the results from retinal thickness measurements obtained with optical coherence–tomopraphy (OCT) and scanning laser topography (HRT II, macula module). Methods: We included 47 patients with diabetic maculopathy into this study. All patients were examined with the OCT and HRT II. Retinal thickness was assessed from retinal thickness maps calculated from 6 OCT scans centered on the fovea using the standard OCT software. Additionally, edema maps were calculated from confocal tomographic images series recorded with the HRT II. Results:Both retinal thickness maps (OCT) and retinal edema maps (HRTII) allowed the identification of regions affected by macular edema and showed a good correlation to biomicroscopy. Mean retinal thickness was 318 ± 120 µm measured by OCT technique and the mean edema index, measured by HRTII was 2.01±0.80. We found a good correlation between between the data measured by OCT and HRTII (r=0.67). The correlation between visual acuity and retinal thickness was r = 0.375. The correlation between visual acuity and edema index was r = 0.410. Conclusions:Both techniques allowed the identification of regions affected by macular edema. However, both techniques have some limitations: Retinal thickness maps calculated from OCT scans are calculated from only 600 measurements points whereas edema index maps are calculated from a total of 147,456 pixel. Quantitative assessment of retinal thickness is only possible from OCT scans. Both methods are non–invasive, OCT requires dilatation of the pupil and a longer examination time than scanning laser topography with the HRT II .
Keywords: diabetes • macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)