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Identifier

000380458

Title

Ποσοτικοποίηση του τριχοειδικού αγγειακού δικτύου της ωχράς κηλίδας σε νεαρούς διαβητικούς ασθενείς

Alternative Title

Quantification of the macular capillary network in yong diabetic patients

Author

Καψάλα, Ζωή Γ

Thesis advisor

Τσιλιμπάρης, Μιλτιάδης

Reviewer

Μοσχανδρέα, Ιωάννα

Abstract

Introduction: The capillary network constitutes an important retinal microstructure which can be very helpful for the diagnosis of many retinal diseases including diabetic retinopathy. Until the recent advances in the computerized analysis, the diabetic macula has been assessed qualitatively. Many attempts have been made in order to create algorithms for the assessment of the capillary network alterations. Purpose: To assess the morphology of the perifoveal capillary network with quantitative parameters in young patients with diabetes mellitus type I (DM I) using an algorithm and to evaluate if these parameters differ between diabetic patients and healthy volunteers and if they correlate with any of the diabetes group characteristics. Sample and methods: Twenty-nine images of 29 eyes (18 eyes of 18 DM I patients and 11 eyes of 11 non DM controls) were chosen from the University Hospital of Heraklion digital fluorescein angiography database. The age was 19±6 years for the patient group (range: 12-30 years) and 17±7 years (range: 6-26 years) for the control group. Patients had a history of DM I for 11±5 years (range: 6-20 years) and best corrected visual acuity (BCVA) at least 20/25. The two groups underwent BCVA assessment, Goldmann applanation tonometry, slit lamp examination and fluorescein angiography. The HbA1c level (%) was also assessed in the patient group. Diabetic retinopathy abnormalities were graded according to ETDRS classification. For each person we selected and assessed the eye with the highest image quality. The high resolution images chosen underwent a processing procedure using the commercial software MatLab R2011a (The MathWorks Inc.). The developed algorithm traces manually the perifoveal capillary network by choosing with the cursor in a subimage of field 5o*5o of the original one including the foveal avascular zone (FAZ) and provides measurements of the capillary density, the branch point density and the FAZ surface in the mentioned area. SPSS 20 was used for the statistical analysis. Results: Patients and controls did not differ in age (p=0.328). Mild non proliferative diabetic retinopathy abnormalities were detected in 7 out of the 18 DM I patients (39%). The mapping revealed a perifoveal capillary density of 2.601±0.535 deg-1 in the DM I group versus 2.933±0.306 deg-1 in the control group and this difference was significant (p=0.047). The branch point density was 3.121±0.793 branch points/deg2 and 3.452±0.689 branch points/deg2 in each group, respectively (p=0.205). The FAZ area was 0.227±0.055 deg2 in the diabetic group and 0.21±0.041 deg2 in the control group (p=0.403). No correlation was detected between any of the three capillary metrics in the DM I group and the age in this group, the DM duration or the HbA1c level. Conclusions: The perifoveal capillary network quantification can be very helpful for the diagnosis and the monitoring of the retinal microvascular alterations in diabetic patients. The quantitative parameters we selected tend to increase or decrease in diabetic patients in agreement with previous studies and only the perifoveal capillary 8 density was significantly decreased in the DM I group when compared to the control group. Further improvement of these parameters and bigger sample size will probably ameliorate the method.

Language

Greek

Subject

Capillaries

Diabetes

Ophthalmology

Quantification

Διαβήτης

Ποσοτικοποίηση

Τριχοειδή

Issue date

2013-04-16