Quantitative analysis of retinal microcirculation in children with type 1 diabetes

Plain English Summary

Background and study aims
Diabetes mellitus is a life-long condition where a person is unable to control their blood sugar levels. There are two main types of diabetes, type 1 (around 10% of cases) and type 2. In type 1 diabetes (T1DM) the immune system attacks specialised cells in the pancreas called beta-cells (which are responsible for producing the hormone insulin). This means that the sufferer is unable to produce enough insulin to effectively control their blood sugar levels and so regularly inject insulin in order to keep their blood sugar levels in a healthy range. DM is also one of the most common chronic disease among children. This chronic disease could affect both anterior and posterior ocular structures of those children. Diabetic retinopathy (DR), which is the most common microvascular complication of type 1 DM, is still one of the leading causes of blindness even in developed countries. Recent technological advances mean that systems are now able to measure the retinal blood vessel density and flow of retina (posterior layer of eyeball that contains cells sensitive to light) in humans with a contrast-free technique. The aim of this study is to compare the retinal microcirculation in children with T1DM and healthy children to look at whether there is a link between diabetes and retinal microcirculation.

Who can participate?
Children aged 6-18 who have T1DM and no eye problems, and healthy children of the same age.





What does the study involve?
All participants attend a single study visit. At the visit, all participants undergo a comprehensive eye examination where optical coherence tomography angiography images are taken of the eye in order to assess retinal microcirculation. Participants who have diabetes also have a number of blood samples taken in order to assess their current blood sugar control. At the end of the study visit, the results between the two groups of participants are compared. In addition, the blood sugar control and length of time the diabetic participants have been diabetic is compared to the results from the eye exams.





What are the possible benefits and risks of participating?
There are no direct benefits involved with participating. There is a small risk of pain or bruising from blood tests.





Where is the study run from?
1. Ulucanlar Eye Training and Research Hospital (Turkey)
2. Children’s Health and Disease Training and Research Hospital (Turkey)

When is the study starting and how long is it expected to run for?
June 2017 to March 2018





Who is funding the study?
Investigator initiated and funded (Turkey)





Who is the main contact?
Merve Inanc, M.D.
mrvn88@hotmail.com

Study website

Type

Scientific

Contact name

Dr Merve Inanc

ORCID ID

http://orcid.org/0000-0002-9930-7680

Contact details

Ulucanlar Eye Training and Research Hospital
Ulucanlar Street Number: 59
ankara
06240
Turkey
+90 (0)536 633 46 91
mrvn88@hotmail.com

EudraCT/CTIS number

Nil known

IRAS number

ClinicalTrials.gov number

Nil known

Protocol/serial number

16-1068

Scientific title

Changes in retinal microcirculation precede the clinical onset of diabetic retinopathy in children with type 1 diabetes mellitus

Acronym

Study hypothesis

The abnormal glucose metabolism in type 1 diabetes mellitus (DM) affects the retinal microcirculation in children with well-controlled Type 1 DM for whom the duration of DM and glycemic control had been well documented.

Ethics approval(s)

Approved 12/04/2016 by Ethics Committee of the Ankara Numune Training and Research Hospital, Talatpasa boulevard, Ulku street, number: 5, Tel: +90 (0)312 508 5910, Email: aneahetikkurul@gmail.com, ref: E-16-1068

Study design

Prospective cross-sectional and case-control study

Primary study design

Observational

Secondary study design

Case-control study

Study setting(s)

Hospital

Study type

Diagnostic

Patient information sheet

Condition

Retinal microcirculation and vessel density

Intervention

All participants attend a single study visit, at which they undergo a comprehensive ophthalmic examination including best corrected visual acuity tests using the Snellen chart, intraocular pressure measurements by a pneumotonometer, slit-lamp biomicroscopy, and dilated fundus examination. High-quality colour stereoscopic fundus photographs are also taken. Refraction measurements are performed by using the same automatic refractor-keratometer device (Canon RF-K2, Japan). Moreover, blood samples are taken for the pre-prandial blood glucose and glycosylated hemoglobin (HbA1c) levels on the same day for the diabetic cases. The duration of DM and the HbA1c levels were recorded. Moreover, to quantify the vessel density and retinal microcirculation, the AngioVue device (Version 2017.1.0.151 of the RTVue XR Avanti, Opto-Vue, Inc, Fremont, CA, USA) was used in the study.

Intervention type

Other

Primary outcome measure

Retinal microcirculation parameters and vessel density indexes are measured using an optical coherence tomography angiography device (the AngioVue device, Version 2017.1.0.151 of the RTVue XR Avanti, Opto-Vue, Inc, Fremont, CA, USA) at the single visit:
1. Foveal zone vessel density: the area of the small circle, with a diameter of 1 mm
2. Parafoveal zone vessel density: the area of the middle circle, with a diameter of 3 mm
3. Perifoveal zone vessel density: the area of the outer circle with a diameter of 6 mm.
4. Foveal avascular zone area
5. Foveal avascular zone perimeter
6. Acircularity index of foveal avascular zone: the ratio of the perimeter of the foveal avascular zone
7. Foveal density (FD-300): vessel density in 300 microns around the foveal avascular zone

Secondary outcome measures

All measurements taken at the single visit (on the day of ocular examination):
1. Duration of diabetes mellitus (since the diagnosis of type 1 diabetes mellitus) measured using medical records
2. Pre-prandial blood glucose and glycosylated hemoglobin (HbA1c) levels measured using blood samples in the diabetic group

Overall study start date

01/06/2017

Overall study end date

30/03/2018

Reason abandoned (if study stopped)

Participant inclusion criteria

Diabetic patient inclusion criteria:
1. Aged 6-18 years
2. Male and female
3. No previous known macular or other retinal changes,
4. No ocular problem other than spherical or cylindrical refractive errors ≤ 1.00 diopter
5. No systemic disease except than Type 1 DM
6. The best-corrected vis6.ual acuity according to Snellen chart equal or greater than 20/20
7. A pre-prandial blood glucose level ≤ 100 mg/dl under insulin treatment
8. Patients who had information about the duration of diabetes mellitus.

Control participant inclusion criteria:
1. Aged 6-18 years
2. Male and female
3. No systemic disease
4. No ocular problem other than spherical or cylindrical refractive errors ≤ 1.00 diopter
5. Best-corrected visual acuity according to Snellen chart equal or greater than 20/20

Participant type(s)

Mixed

Age group

Child

Lower age limit

6 Years

Upper age limit

18 Years

Sex

Both

Target number of participants

110

Participant exclusion criteria

All participants:
1. Strabismus
2. Nystagmus
3. History of previous ocular surgery or laser treatment
4. Trauma or uveitis
5. Corneal diseases such as corneal scar
6. Fundus abnormalities including diabetic retinopathy/maculopathy
7. Optic nerve diseases and glaucoma
8. Neurological disease or other diseases of the visual pathways
9. Ocular media opacities including cataract
10. Use of chronic topical medication
11. Those who are not sufficiently cooperative for optical coherence tomography angioraphy examinations

Recruitment start date

15/06/2017

Recruitment end date

31/12/2017

Countries of recruitment

Turkey

Study participating centre

Ulucanlar Eye Training and Research Hospital
Ulucanlar Street Number:59, 06240
ankara
06240
Turkey

Study participating centre

Sami Ulus Children’s Health and Disease Training and Research Hospital
Babur Street, Number: 44
ankara
06230
Turkey

Organisation

Ulucanlar Eye Training and Research Hospital

Sponsor details

Ulucanlar Street Number:59
Ankara
06240
Turkey
+90 (0)312 312 62 61
ulucanlargoz@saglik.gov.tr

Sponsor type

Hospital/treatment centre

Website

http://ulucanlargoz.gov.tr/

ROR

https://ror.org/045d4f586

Funder type

Other

Funder name

Investigator initiated and funded

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Publication and dissemination plan

Planned publication in a high-impact peer reviewed journal between May 2019 and May 2020.

Intention to publish date

15/04/2019

Individual participant data (IPD) sharing plan

The datasets generated during and/or analysed during the current study are/will be available upon request from Merve Inanc M.D. (mrvn88@hotmail.com)

IPD sharing plan summary

Available on request

Study outputs