Session Title: Free Paper Session 19: Vascular Diseases & Diabetic Retinopathy V
Session Date/Time: Saturday 09/09/2017 | 16:30-18:00
Paper Time: 17:36
Venue: Room 120
First Author: : T.Um SOUTH KOREA
Co Author(s): : Y. Yoon E. Seo
To investigate the optical coherence tomography angiography (OCT-A) parameters in type 1 diabetes with diabetic retinopathy (DR) and compare with those in type 2 diabetes.
Retrospective, observational study in a tertiary referral centre
Seventy patients with type 1 diabetes were analyzed in this study. DR was graded as 5 stages by using fluorescein angiography (FA) and fundus exam: no DR, mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR, and proliferative DR (PDR). Patients without macular edema confirmed by spectral domain-optical coherence tomography were finally enrolled. Foveal 3x3 mm2 scan OCT-A images were taken using split-spectrum amplitude decorrelation angiography (SSADA) software algorithm. Image J software was used to calculate foveal avascular zone (FAZ) area (mm2) and vascular density (VD) (%) from both superficial capillary plexus (SCP) and deep capillary plexus (DCP). All parameters were compared using GEE (generalized estimating equation) method with identity link and normal distribution.
Of 70 patients with type 1 diabetes, 24 patients had no DR, 14 mild NPDR, 7 moderate NPDR, 10 severe NPDR, and 15 PDR. Mean of age, duration of diabetes, glycated haemoglobin A1c (HbA1c), and visual acuity were 27.0±9.5 years, 13.9±7.1 years, 8.1±2.3 % and 0.92±0.13. The duration of diabetes was significantly shorter in no DR group as 7.9±4.7 years (P<0.01), than any other groups (16.4 to 17.4 years). HbA1c was not significantly different among 5 groups (P=0.137). FAZ area (mm2) in SCP and DCP became larger as the stage of DR progressed (no DR, 0.307 and 0.393; mild NPDR, 0.346 and 0.391; moderate NPDR, 0.357 and 0.470; severe NPDR, 0.381 and 0.618; PDR, 0.516 and 0.828, P<0.001 and <0.001). Also, VD (%) in SCP and DCP progressively decreased (no DR, 33.77 and 44.21; mild NPDR, 36.12 and 44.31; moderate NPDR, 32.75 and 39.27; severe NPDR, 30.90 and 36.55; PDR, 27.01 and 24.09, P<0.001 and <0.001). The change in VD over DR progression was significantly bigger in DCP than that in SCP (P=0.005). These findings were similar to type 2 diabetes.
OCT-A in type 1 diabetes with DR showed the worsening of FAZ area and VD in SCP and DCP as DR progressed. The decrease in VD was more severe in DCP than in SCP.