Hybrid closed loop insulin pumps and early worsening of diabetic retinopathy in Type 1 diabetes

Evaluating the association between hybrid closed-loop insulin pump therapy and early worsening of diabetic retinopathy in adults with Type 1 diabetes over a 24-month period: a prospective cohort comparison with multiple daily injections or stand-alone CSII

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN11740459

Enrollment

203

Registered

2025-12-22

Start date

2025-05-07

Completion date

Unknown

Last updated

2026-01-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Type 1 diabetes Nutritional, Metabolic, Endocrine

Interventions

All participants will undergo digital colour fundoscopy, optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), electroretinography (ERG), routine blood tests, additional

Eligibility

Sex/Gender

All

Age

18 Years to 100 Years

Inclusion criteria

Inclusion criteria: HCL group: 1. Able to attend screening visit within 28 days of initiation on a HCL 2. Baseline HbA1c =58 mmol/mol Control group: 1. Does not meet the national criteria for HCL initiation (MDI or stand alone/open loop insulin pump)

Exclusion criteria

Exclusion criteria: 1. Pregnancy. This is because pregnancy is an established risk factor for EWDR and would be a significant confounding variable 2. Unable to give informed consent 3. Type 2 diabetes, MODY, cystic fibrosis related diabetes, other secondary causes of diabetes

Design outcomes

Primary

Measure	Time frame
The rate of early worsening of diabetic retinopathy (EWDR) in individuals who are newly initiated on a hybrid closed loop insulin pump (HCL). EWDR will be defined as either: 1.Two-step change in the Early Treatment of Diabetic Retinopathy Study scale (ETDRS) or 2. Progression to clinically significant macular oedema (CSMO) or 3. Progression to treatment of diabetic retinopathy (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months)	—

Measure

Time frame

The rate of early worsening of diabetic retinopathy (EWDR) in individuals who are newly initiated on a hybrid closed loop insulin pump (HCL). EWDR will be defined as either: 1.Two-step change in the Early Treatment of Diabetic Retinopathy Study scale (ETDRS) or 2. Progression to clinically significant macular oedema (CSMO) or 3. Progression to treatment of diabetic retinopathy (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months)

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Secondary

Measure	Time frame
1. The rate of one-step change in ETDRS (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 2. The difference in rate of EWDR between individuals on HCL and individuals on multiple daily injections (MDI) measured using either: i) two-step change in ETDRS or ii) progression to clinically significant macular oedema (CSMO) or iii) progression to treatment of diabetic retinopathy] (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 3. Quantification of the changes in the retinal microvasculature in individuals who are started on a HCL (retinal thickness, ganglion cell layer, retinal nerve fibre layer, capillary plexus, retinal neurophysiology, foveal avascular zone, acicularity index measured using in-built automated software and image segmentation techniques) (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 4. Evaluation of continuous glucose monitoring (CGM) metrics (% time in range, % time above and below range, glycaemic variability, glucose management index, average glucose) in relation to two-step and one-step change in ETDRS (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 5. Alterations in serum growth factors in individuals who develop EWDR compared to individuals who do not, measured using multiplex assays (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months)	—

Measure

Time frame

1. The rate of one-step change in ETDRS (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 2. The difference in rate of EWDR between individuals on HCL and individuals on multiple daily injections (MDI) measured using either: i) two-step change in ETDRS or ii) progression to clinically significant macular oedema (CSMO) or iii) progression to treatment of diabetic retinopathy] (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 3. Quantification of the changes in the retinal microvasculature in individuals who are started on a HCL (retinal thickness, ganglion cell layer, retinal nerve fibre layer, capillary plexus, retinal neurophysiology, foveal avascular zone, acicularity index measured using in-built automated software and image segmentation techniques) (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 4. Evaluation of continuous glucose monitoring (CGM) metrics (% time in range, % time above and below range, glycaemic variability, glucose management index, average glucose) in relation to two-step and one-step change in ETDRS (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months) 5. Alterations in serum growth factors in individuals who develop EWDR compared to individuals who do not, measured using multiplex assays (baseline vs 3 months; baseline vs 6 months; baseline vs 12 months)

—

Countries

England, United Kingdom

Contacts

Public ContactMatthew Anson

manson1@liverpool.ac.uk+44 (0)151 529 5917

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026