Abstract
Purpose :
To evaluate early changes of retinal layers as evaluated by Optical Coherence Tomography (OCT) in patients with long standing diabetes type 1 under intensified insulin therapy.
Methods :
All 152 patients of a cross-sectional study and 152 age- and gender-matched healthy controls underwent spectral-domain OCT imaging with Heidelberg Spectralis (49 B-scans, 15 frames). Patients were included if they had type 1 diabetes mellitus diagnosed between 5 and 25 years prior to screening and were on intensified insulin therapy from the beginning of the disease. OCT scans of both eyes were analyzed for 5 different layers (nerve fibre layer (NFL), ganglion cell layer and inner plexiform layer (GCL), inner nuclear layer (INL), outer plexiform layer, outer nuclear layer, external limiting membrane until photoreceptor inner segments begin, called the outer layer complex (OLC), photoreceptors (PR)) in all subfields of a fovea-centered early treatment diabetic retinopathy study (ETDRS) grid. All analyses were performed by the Vienna Reading Center in custom software. For comparison of mean thickness of the layers between patients and controls ANOVA-models have been performed.
Results :
The mean thickness of the layers in patients vs. controls (in µm) was 31.88 vs. 30.80 (NFL), 77.03 vs. 72.93 (GCL), 36.22 vs. 37.09 (INL), 113.99 vs. 112.18 (OLC) and 44.76 vs. 44.65 (PR). Thickening in patients was significant in NFL (p=0.0015), GLC (p=<0.0001) and OLC (p<0.0001). The INL showed a significant thinning in patients (p=0.0117). There was no significant change found for the PR layer. The overall thickening was pronounced for the outer subfields.
Conclusions :
These results demonstrate, that preclinical changes in the retina of atients with long standing diabetes type 1 can be found by retinal layer evaluation by OCT. However the changes are layer specific, with significant thickening of the NFL, GCL and OLC and thinning of the INL. Interestingly the PR layer did not show a difference between patients and normal controls.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.