Macular Thickness Evaluation in Young Patients With Type 1 Diabetes Mellitus and Healthy Controls

Abstract

Purpose: The objectives of this study were to (1) compare macular thickness (MT) in young patients with type 1 diabetes mellitus (DM) versus healthy controls and (2) evaluate the influence of metabolic control, blood glucose excursion and disease duration on macular thickness in patients with type 1 diabetes mellitus (DM).

Methods: 50 eyes of 25 young patients with type 1 diabetes mellitus without signs of diabetic retinopathy and 26 eyes of 13 young healthy controls were considered. Mean patients age was 15 years (range 7-18). Diabetic patients were divided into 2 groups: 22 eyes (Group 1) with poor metabolic control (HbA1c > 8.1%), 28 eyes (Group 2) with good metabolic control (HbA1c < 8.1%). Group 1 and 2 were respectively compared with healthy controls (Group 3). All patients underwent full clinical examination and instrumental evaluation included Spectral Domain OCT macular cross sectional and macular thickness studies for the pericentral and peripheral area of the macula. All statistical analysis was performed using Mann-Whitney test.

Results: All eyes presented a visual acuity of 20/20. All diabetic patients (Group 1 and 2) showed in comparison to Group 3 a no significant difference (p>0.05) on average MT (216.17 ± 14.38 μm vs 228.14 ± 13.84 μm), a significant lower (p<0.05) pericentral MT (228.08 ± 4.35 μm vs 301.75 ± 7.84 μm ) and no significant difference in peripheral MT (224.52 ± 0.46 μm vs 230.19 ± 12.78 μm). Group 1 showed in comparison to Group 2 a significant (p<0.05) difference on average MT (206 ± 23.00 μm vs 226.34 ± 14.91 μm), a significant lower pericentral MT (225 ± 14.64 μm vs 231.16 ± 14.50 μm ) and no significant difference in peripheral MT (224.19 ± 14.49 μm vs 224.85 ± 14.57 μm). Statistically significant inverse simple correlations were present between RT and blood glucose excursion (p<0.01), blood glucose (p<0.02) and insulin requirement (p<0.05). No correlation were found between RT and disease duration.

Conclusions: Our study shows (1) a significant reduction in pericentral macular thickness in young type 1 diabetic patients versus healthy controls; (2) a mean MT and pericentral MT reduction in type 1 diabetic patients with poor metabolic control vs good metabolic control. MT reduction can represent the first sign of retinal involvement by diabetic microangiopathy and is associated with poor metabolic control but not with disease duration.

Keywords: 499 diabetic retinopathy • 550 imaging/image analysis: clinical • 585 macula/fovea