Single Session vs Multiple-Session Panretinal Photocoagulation for Treatment of Proliferative Diabetic Retinopathy (SMART-PRP)

November 17, 2025 updated by: Vastra Gotaland Region

Single Session vs Multiple-Session Panretinal Photocoagulation With Navigated Laser in Proliferative Diabetic Retinopathy - The SMART-PRP Study

Proliferative diabetic retinopathy (PDR) is the leading cause for blindness in working-age adults. The current gold standard treatment for PDR is panretinal photocoagulation (PRP). In current clinical practice, both single-session and multiple-session PRP approaches are widely accepted and utilized. The purpose of this study is to compare the safety and effectiveness of single-session and multiple-session PRP.

Study Overview

Detailed Description

Proliferative diabetic retinopathy (PDR) is a well-known complication for both type 1 and type 2 diabetes mellitus (DM) and it is the leading cause for blindness in working-age adults. The current gold standard treatment for PDR, established more than four decades ago by the Diabetic Retinopathy Study (DRS), is panretinal photocoagulation (PRP). The treatment goal is to halt the progression of PDR by destroying parts of the peripheral retina in a pattern fashion and hence preserving the visually important central macular region. The tissue destruction reduces the area of ischemia and reduces the production of vascular endothelial growth factor (VEGF), which drives the formation of neovascular proliferations. In the management of PDR, panretinal photocoagulation (PRP) stands as a cornerstone treatment. In current clinical practice, both single-session and multiple-session PRP approaches are widely accepted and utilized. The choice between these approaches often depends on the practitioner's preference, patient characteristics, and specific clinical circumstances.

Although both single-session and multiple-session PRP are employed in practice, there's an ongoing debate regarding their comparative safety and effectiveness. Older studies suggest a heightened risk of diabetic macular edema (DME) with single-session PRP, while newer research, particularly those involving milder laser techniques, indicates that the risk might be similar regardless of the number of sessions. This inconsistency in findings underscores the need for further research and the investigators aim to shed light over this with this prospective, controlled and randomized interventional study.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age > 18 years.
  • Patients with type 1 or type 2 Diabetes Mellitus with newly diagnosed Proliferative Diabetic Retinopathy, PDR.
  • Visual acuity ≥ 0.1 Snellen.
  • CRT of less than 300 micrometer measured by OCT without cysts in the neuroretina.
  • Clear media and adequately dilated pupil for PRP.

Exclusion Criteria:

  • Intraocular surgery within the last 4 months or planned within the next 3 months.
  • Previous or current center-involved diabetic macular edema (Ci-DME).
  • Previous PRP, intravitreal treatment (IVT), or macular laser treatment in study eye.
  • Treatment with medications known to risk macular edema.
  • Media opacity preventing adequate PRP.
  • General medical condition making office laser treatment very difficult or impossible.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Single-session panretinal PRP (SS-PRP)
Administration of all panretinal photocoagulation (PRP) treatment in one comprehensive session, typically delivered in a single clinical visit.
Administration of panretinal photocoagulation (PRP) treatment with navigated laser using Navilas in one comprehensive session, typically delivered in a single clinical visit.
Active Comparator: Multiple-session panretinal PRP (MS-PRP)
Administration of panretinal photocoagulation (PRP) treatment over two separate visits with at least one week apart.
Administration of panretinal photocoagulation (PRP) treatment with navigated laser using Navilas over two separate visits with at least one week apart.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Central subfield retinal thickness (CRT)
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in CRT
Baseline and 1, 3 and 6 months after treatment
Vessel Perfusion Density (VPD)
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in VPD
Baseline and 1, 3 and 6 months after treatment
Vessel Length Density (VLD)
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in VLD
Baseline and 1, 3 and 6 months after treatment
Foveal Avascular Zone (FAZ)
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in FAZ
Baseline and 1, 3 and 6 months after treatment
Lesion size
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in lesion size
Baseline and 1, 3 and 6 months after treatment
Macular volume
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in macular volume
Baseline and 1, 3 and 6 months after treatment
Venular saturation
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in venular saturation
Baseline and 1, 3 and 6 months after treatment
Arteriolar saturation
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in arteriolar saturation
Baseline and 1, 3 and 6 months after treatment
Retinal diameter
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in retinal diameter
Baseline and 1, 3 and 6 months after treatment
Venular diameter
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in venular diameter
Baseline and 1, 3 and 6 months after treatment
Retinal function
Time Frame: Baseline and 1, 3 and 6 months after treatment
Mean change from baseline in retinal function using full-field electroretinogram (ERG)
Baseline and 1, 3 and 6 months after treatment
Diabetic macular edema (DME)
Time Frame: Baseline and 1, 3 and 6 months after treatment
Incidence of diabetic macular edema (DME)
Baseline and 1, 3 and 6 months after treatment
Subjective experience of pain after treatment
Time Frame: Baseline and 1, 3 and 6 months after treatment
Study patients' subjective experience of pain after treatment using visual analog scale (VAS)
Baseline and 1, 3 and 6 months after treatment
Subjective overall experience of the treatment
Time Frame: Baseline and 1, 3 and 6 months after treatment
Study patients' subjective overall experience of the treatment using verbal scale (VS)
Baseline and 1, 3 and 6 months after treatment
Cost-effectiveness
Time Frame: Baseline and 1, 3 and 6 months after treatment

We intend to conduct a thorough cost-effectiveness analysis, comparing the single-session approach with the traditional multiple-session treatments.

This analysis will factor in direct medical costs, including the expenses related to the laser equipment, healthcare professionals' time, and the required clinical facilities. We will also consider indirect costs such as patient travel expenses and time taken off work.

Baseline and 1, 3 and 6 months after treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Marita Andersson Grönlund, M.D. Prof, Göteborg University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2025

Primary Completion (Estimated)

December 31, 2028

Study Completion (Estimated)

December 31, 2030

Study Registration Dates

First Submitted

August 8, 2024

First Submitted That Met QC Criteria

August 8, 2024

First Posted (Actual)

August 12, 2024

Study Record Updates

Last Update Posted (Actual)

November 18, 2025

Last Update Submitted That Met QC Criteria

November 17, 2025

Last Verified

October 1, 2025

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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