Abstract
Purpose :
To evaluate peripapillary vessel perfusion density (PVD) and correlate it to retinal nerve fiber layer (RNFL) thickness in the peripapillary area in patients with diabetes mellitus (DM).
Methods :
117 eyes of 117 consecutive subjects (34 healthy controls, 54 patients with DM without diabetic retinopathy (noDR) group and 24 patients with mild DR (DR group)) were prospectively evaluated. All subjects underwent a complete ophthalmologic evaluation and Swept-Source Optical Coherence Tomography Angiography (SS-OCTA) (DRI OCT Triton plus Topcon Medical Systems Europe, Milano, Italy) in a standardized fashion with 4.5mm x 4.5mm scan centered on the papilla. Peripapillary RNFL was also recorded by a 3D Disc scan covering 6 × 6mm raster scan centered on the optic disc. Exclusion criteria were any ocular or systemic disease other then DM, any previous eye surgery. OCT-A slab of Radial Peripapillary Plexus (RPC) were analyzed with ImageJ (version 1.51p, provided in the public domain by the U.S. NIH) in order to manually remove the papilla and to allow binarization and skeletonization of the images. Further a skeleton analysis (ImageJ plug in) was performed to identify all branches, representing the number of vessels in the area (PVD). Statistical analysis was performed with two-tailed Student’s T-test and one-way analysis of variance corrected for covariates (ANCOVA) including the age and blood pressure (BP).
Results :
Mean age was 43.9±11.9 in controls, 53.0±18.9 in noDR and 68.7±12.3 in DR group (p<0.001); mean BP was 130.1±2.0 mmHg in controls, 138.3±5.7 mmHg in noDR and 141.8±5.3 mmHg in DR group, (p<0.001). There was no significant difference in IOP among the three groups and neither in HbA1c and DM duration between no DR and DR groups. PVD progressively decreased from controls to no DR and DR group, reaching statistical significance in DR (p=0,025). RNFL thickness progressively decreased from controls to no DR and DR group, p<0.05. PVD was significantly correlated to RNFL thickness in all three groups (r=0.5, p<0,05).
Conclusions :
PVD and RNFL thickness were reduced in patients with DM versus controls. A significant decrease in both parameters was found only in DR group vs controls. These data may help for further studies in evaluating early neuronal and vascular changes in DM.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.