Adolescent Macular Thickness and Vascular Caliber in the Presence of Type 1 and Type 2 Diabetes

Abstract

Purpose: : To examine macular thickness and retinal vascular caliber and the relationship between the two in adolescents with type 1 and type 2 diabetes.

Methods: : Thirty-two adolescents with type 1 diabetes (5.7 ± 3.6 yrs diabetes duration) and 15 adolescents with type 2 diabetes (2.1 ± 1.3 yrs) were examined. Twenty-six age-matched subjects without diabetes served as controls. Digital fundus photographs of the central 45 degrees of the retina were acquired and examined by a masked retinal specialist. All groups were without vascular lesions in either eye. The mean macular thicknesses in 37 hexagonal regions were derived from twelve radial scans, 6 mm long, centered at the fovea, using Stratus OCT 3. The average arteriolar and venular diameters within ½ to 1 disc diameter around the optic nerve were analyzed with IVAN (University of Wisconsin-Madison, WI) using the Parr and Spears’ algorithm. T-tests were used to compare the mean differences between groups and linear regression analysis was used to look for associations between macular thickness and vascular caliber.

Results: : The mean macular thickness of the type 2 group (243.4 ± 3.3 µm, Mean ± SE) was significantly (p < 0.03) thinner than that of the control group (253.7 ± 2.5 µm) but did not differ from the type 1 group (249.9 ± 2.4 µm). The mean venular caliber of the type 2 group (235.8 ± 5.9 µm) was significantly larger (p < 0.05) than the control group’s (219.6 ± 4.0 µm). The type 1 group (223.2 ± 4.1 µm) did not differ (p > 0.05) from either the type 2 or control groups. The mean arteriolar caliber of the type 1 (171.5 ± 3.2 µm) and type 2 (165.5 ± 4.0 µm) groups did not differ (p > 0.05) from that of the control group (172.1 ± 3.5 µm). Retinal thickness was positively correlated with arteriole caliber in the type 1 group (p < 0.01). There were no other significant associations.

Keywords: diabetes • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • diabetic retinopathy