Limits...
Retinal haemodynamics in individuals with well-controlled type 1 diabetes.

Lorenzi M, Feke GT, Cagliero E, Pitler L, Schaumberg DA, Berisha F, Nathan DM, McMeel JW - Diabetologia (2007)

Bottom Line: The study participants were not taking vasoactive medications, and blood glucose at the time of haemodynamic measurements was required to be between 3.8 and 11.1 mmol/l.Retinal blood speed, arterial diameter and blood flow were not different between the diabetic individuals and the matched controls.Type 1 diabetic patients with no or minimal retinopathy who maintain relatively good glycaemic control do not show abnormalities of the retinal circulation at steady state, even after several years of diabetes.

View Article: PubMed Central - PubMed

Affiliation: Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, and Diabetes Center and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA. mara.lorenzi@schepens.harvard.edu

ABSTRACT

Aims/hypothesis: Abnormalities in retinal haemodynamics have been reported in patients with type 1 diabetes in advance of clinical retinopathy. These abnormalities could therefore be useful as early markers or surrogate endpoints for studying the microangiopathy. Since the DCCT, the increased focus on good glycaemic control is changing the natural history of diabetic retinopathy. Based on this, the aim of this study was to investigate whether patients with type 1 diabetes treated entirely or mostly in the post-DCCT era and tested in the absence of confounding factors show retinal haemodynamic abnormalities.

Methods: We measured retinal haemodynamics by laser Doppler flowmetry in 33 type 1 diabetic individuals with no or minimal retinopathy (age 30+/-7 years, duration of diabetes 8.8+/-4.6 years, 9% showing microaneurysms), and 31 age- and sex-matched non-diabetic controls. The study participants were not taking vasoactive medications, and blood glucose at the time of haemodynamic measurements was required to be between 3.8 and 11.1 mmol/l.

Results: HbA1c was 7.5+/-1.2% and blood glucose 7.7+/-2.8 mmol/l in these type 1 diabetic individuals, indicating relatively good glycaemic control. Retinal blood speed, arterial diameter and blood flow were not different between the diabetic individuals and the matched controls.

Conclusions/interpretation: Type 1 diabetic patients with no or minimal retinopathy who maintain relatively good glycaemic control do not show abnormalities of the retinal circulation at steady state, even after several years of diabetes. In such patients it may be necessary to test the vascular response to challenges to uncover any subtle abnormalities of the retinal vessels.

Show MeSH

Related in: MedlinePlus

Retinal haemodynamic parameters in type 1 diabetic individuals and matched non-diabetic controls. The box plots present the data for the 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Each box plot shows the 10th, 25th, 50th (median), 75th and 90th percentiles of the indicated parameter. Values above the 90th and below the 10th percentile are plotted as points
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2170455&req=5

Fig1: Retinal haemodynamic parameters in type 1 diabetic individuals and matched non-diabetic controls. The box plots present the data for the 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Each box plot shows the 10th, 25th, 50th (median), 75th and 90th percentiles of the indicated parameter. Values above the 90th and below the 10th percentile are plotted as points

Mentions: Figure 1 presents the retinal haemodynamic measurements in 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Arterial diameter and blood speed were not significantly different between the diabetic patients and the controls (diameter: patients 116 ± 12 μm, controls 112 ± 10 μm, p = 0.18; blood speed: patients 32.9 ± 6.0 mm/s, controls 34.6 ± 6.8 mm/s, p = 0.34). Accordingly, retinal blood flow was the same in the two groups (patients 10.4 ± 2.4 μl/min; controls 10.4 ± 3.2 μl/min, p = 0.98). In the remaining six diabetic and five control participants there was early bifurcation of the artery, and one of the branches was used for the measurements; again, no differences were noted between the two groups. The sample size provided 80% power (α = 0.05) to detect differences as low as 0.75 SD between diabetic and control participants. This translates into differences of 7, 15 and 24% for retinal artery diameter, blood speed and blood flow, respectively.Fig. 1


Retinal haemodynamics in individuals with well-controlled type 1 diabetes.

Lorenzi M, Feke GT, Cagliero E, Pitler L, Schaumberg DA, Berisha F, Nathan DM, McMeel JW - Diabetologia (2007)

Retinal haemodynamic parameters in type 1 diabetic individuals and matched non-diabetic controls. The box plots present the data for the 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Each box plot shows the 10th, 25th, 50th (median), 75th and 90th percentiles of the indicated parameter. Values above the 90th and below the 10th percentile are plotted as points
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2170455&req=5

Fig1: Retinal haemodynamic parameters in type 1 diabetic individuals and matched non-diabetic controls. The box plots present the data for the 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Each box plot shows the 10th, 25th, 50th (median), 75th and 90th percentiles of the indicated parameter. Values above the 90th and below the 10th percentile are plotted as points
Mentions: Figure 1 presents the retinal haemodynamic measurements in 27 diabetic and 26 control participants in whom the measurements could be performed at the major superior temporal artery. Arterial diameter and blood speed were not significantly different between the diabetic patients and the controls (diameter: patients 116 ± 12 μm, controls 112 ± 10 μm, p = 0.18; blood speed: patients 32.9 ± 6.0 mm/s, controls 34.6 ± 6.8 mm/s, p = 0.34). Accordingly, retinal blood flow was the same in the two groups (patients 10.4 ± 2.4 μl/min; controls 10.4 ± 3.2 μl/min, p = 0.98). In the remaining six diabetic and five control participants there was early bifurcation of the artery, and one of the branches was used for the measurements; again, no differences were noted between the two groups. The sample size provided 80% power (α = 0.05) to detect differences as low as 0.75 SD between diabetic and control participants. This translates into differences of 7, 15 and 24% for retinal artery diameter, blood speed and blood flow, respectively.Fig. 1

Bottom Line: The study participants were not taking vasoactive medications, and blood glucose at the time of haemodynamic measurements was required to be between 3.8 and 11.1 mmol/l.Retinal blood speed, arterial diameter and blood flow were not different between the diabetic individuals and the matched controls.Type 1 diabetic patients with no or minimal retinopathy who maintain relatively good glycaemic control do not show abnormalities of the retinal circulation at steady state, even after several years of diabetes.

View Article: PubMed Central - PubMed

Affiliation: Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, and Diabetes Center and Department of Medicine, Massachusetts General Hospital, Boston, MA, USA. mara.lorenzi@schepens.harvard.edu

ABSTRACT

Aims/hypothesis: Abnormalities in retinal haemodynamics have been reported in patients with type 1 diabetes in advance of clinical retinopathy. These abnormalities could therefore be useful as early markers or surrogate endpoints for studying the microangiopathy. Since the DCCT, the increased focus on good glycaemic control is changing the natural history of diabetic retinopathy. Based on this, the aim of this study was to investigate whether patients with type 1 diabetes treated entirely or mostly in the post-DCCT era and tested in the absence of confounding factors show retinal haemodynamic abnormalities.

Methods: We measured retinal haemodynamics by laser Doppler flowmetry in 33 type 1 diabetic individuals with no or minimal retinopathy (age 30+/-7 years, duration of diabetes 8.8+/-4.6 years, 9% showing microaneurysms), and 31 age- and sex-matched non-diabetic controls. The study participants were not taking vasoactive medications, and blood glucose at the time of haemodynamic measurements was required to be between 3.8 and 11.1 mmol/l.

Results: HbA1c was 7.5+/-1.2% and blood glucose 7.7+/-2.8 mmol/l in these type 1 diabetic individuals, indicating relatively good glycaemic control. Retinal blood speed, arterial diameter and blood flow were not different between the diabetic individuals and the matched controls.

Conclusions/interpretation: Type 1 diabetic patients with no or minimal retinopathy who maintain relatively good glycaemic control do not show abnormalities of the retinal circulation at steady state, even after several years of diabetes. In such patients it may be necessary to test the vascular response to challenges to uncover any subtle abnormalities of the retinal vessels.

Show MeSH
Related in: MedlinePlus