Evaluation Of Retinal Thickness In Young Patients With Type 1 Diabetes Mellitus

Abstract

Purpose: : To evaluate the influence of metabolic control, blood glucose excursion and disease duration on retinal thickness (RT) in young patients with type 1 diabetes mellitus (DM).

Methods: : 50 eyes of 25 young patients with type 1 diabetes mellitus without signs of diabetic retinopathy were considered. Mean patients age was 15 years (range 7-18), disease duration 71 months (range 7-152 ), mean insulin requirement 0.8 U/Kg/day (range 0.3-1.2), mean HbA1c 8.1% (range 6.5-11.2) and mean blood glucose 165 mg/dl (range 118-275). 22 eyes (Group 1) with poor metabolic control (HbA1c > 8.1%) were compared with 28 eyes (Group 2) with good metabolic control (HbA1c < 8.1%). All patients underwent full clinical examinations and instrumental evaluations included retinal thickness topography map (ETDRS study radial grid) by Spectral domain OCT (OTI-OPKO, Toronto, Canada). Statistical analysis was performed using Mann-Whitney test.

Results: : All eyes had a visual acuity of 20/20. Group 1 showed in comparison to Group 2: a significant (p<0.05) thinner central retinal thickness (206.00 ± 23.00 μm vs 226.34 ± 14.91 μm), a significant lower pericentral macular thickness (225.00 ± 14.64 μm vs 231.16 ± 14.50 μm ) and no significant difference in paracentral macular thickness (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 results suggest that mean central and pericentral retinal thickness decrease in type 1 diabetic patients with poor metabolic control. Retinal thickness 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: diabetes • imaging/image analysis: clinical • diabetic retinopathy