Subtenon PRP Injection for Geographic Atrophy in Dry Age-Related Macular Degeneration (GA-PRP)

February 17, 2026 updated by: Nimet Zeynep Tıraş, Marmara University Pendik Training and Research Hospital

Effects of Subtenon Autologous Platelet-Rich Plasma Injection on Geographic Atrophy Progression, Visual Function, and Quality of Life in Advanced Dry Age-Related Macular Degeneration

This study investigates the effects of subtenon autologous platelet-rich plasma (PRP) injections on retinal structure and visual function in patients with advanced dry age-related macular degeneration (AMD).

PRP is derived from the patient's own blood and contains growth factors that may support cell survival and tissue repair. These factors are thought to help reduce retinal cell loss and slow disease progression.

Three PRP injections were administered to the better-seeing eye at 4-week intervals, while the fellow eye served as an untreated control. Participants were followed from baseline to 10 weeks (two weeks after the third injection).

The aim is to compare changes in RPE atrophy area, photoreceptor loss, and visual function between treated and untreated eyes.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in the elderly population. Geographic atrophy (GA), the advanced form of dry AMD, is characterized by progressive loss of the retinal pigment epithelium (RPE), photoreceptors, and choriocapillaris, resulting in gradual decline of visual function. Current treatment options for GA remain limited, and therapeutic strategies aimed at slowing retinal neurodegeneration represent an important unmet clinical need.

Platelet-rich plasma (PRP) is an autologous blood-derived product containing multiple growth factors, including platelet-derived growth factor (PDGF), insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF), transforming growth factor-β (TGF-β), hepatocyte growth factor (HGF), and basic fibroblast growth factor (bFGF). These bioactive molecules are associated with neuroprotective, anti-apoptotic, and regenerative effects in various tissues.

This prospective, controlled, intra-individual comparative study evaluates the effects of subtenon autologous PRP injections on structural and functional outcomes in patients with advanced dry AMD with GA. In each participant, the eye with better baseline visual acuity received treatment, while the fellow eye served as an untreated control. Three subtenon PRP injections were administered at 4-week intervals, and patients were followed from baseline to 10 weeks, corresponding to two weeks after the third injection.

Structural outcomes were evaluated based on RPE atrophy and photoreceptor loss area. RPE atrophy area was measured using both fundus autofluorescence (FAF) imaging and optical coherence tomography (OCT), whereas photoreceptor loss area was assessed using OCT. OCT measurements were performed using validated deep learning-based segmentation software, while FAF measurements were obtained using semi-automated image analysis.

Visual function was evaluated through best-corrected visual acuity (BCVA), MNREAD reading performance parameters, and multifocal electroretinography (mfERG). Vision-related quality of life was assessed using the NEI VFQ-25 questionnaire. Changes in structural and functional parameters were compared between PRP-treated eyes and untreated fellow eyes.

This study investigates whether subtenon PRP administration may slow retinal structural degeneration and help preserve visual function in patients with GA secondary to dry AMD.

Study Type

Interventional

Enrollment (Actual)

14

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 Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye), 34899
        • Marmara University School of Medicine, Department of Ophthalmology

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:

  1. Age ≥ 60 years
  2. Diagnosis of advanced dry age-related macular degeneration (AMD) in both eyes
  3. No previous ocular treatment for AMD
  4. History of ocular surgery limited to cataract surgery performed ≥1 year prior

Exclusion Criteria:

  1. Media opacities interfering with retinal imaging assessment
  2. Any ocular disease other than dry AMD that could affect retinal structure or function
  3. Evidence of macular neovascularization
  4. Previous intraocular surgery other than cataract surgery
  5. Systemic or ocular conditions that could affect study compliance or visual testing reliability

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: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PRP-Treated Eye
The better-seeing eye receives three subtenon injections of autologous platelet-rich plasma (PRP) at 4-week intervals. This arm is used to evaluate the effect of PRP treatment on the progression of geographic atrophy and visual function parameters over the follow-up period.
Procedure: Subtenon Autologous Platelet-Rich Plasma Injection
Autologous platelet-rich plasma prepared from the participant's peripheral blood is administered via subtenon injection under sterile conditions. Each treated eye receives three injections at monthly intervals.
No Intervention: Untreated Fellow Eye
The fellow eye does not receive PRP treatment and is followed according to the same evaluation schedule. This arm serves as a within-subject comparison to assess the natural course of geographic atrophy and changes in visual function over time.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Retina Pigment Epithelium Atrophy Area (mm²)
Time Frame: Baseline (Week 0) to 2 weeks after the third PRP injection (Week 10)
Retina pigment epithelium (RPE) atrophy area will be quantified using both fundus autofluorescence (FAF) and optical coherence tomography (OCT). OCT measurements will be performed using a previously validated deep learning-based automated algorithm (RetInSight GA Monitor), and FAF measurements will be obtained using semi-automated image analysis software (RegionFinder). Changes in RPE atrophy area (mm²) will be compared between the PRP-treated eye and the fellow untreated eye.
Baseline (Week 0) to 2 weeks after the third PRP injection (Week 10)
Retina Pigment Epithelium Atrophy Growth Rate (Square root transformed, mm/year)
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Retina pigment epithelium (RPE) atrophy growth rates will be calculated from square root transformed lesion areas to reduce bias related to baseline lesion size. Growth rates derived from square-root-transformed areas will be expressed in millimeters per year (mm/year). Growth rates will be compared between the PRP-treated eye and the fellow untreated eye.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Change in Photoreceptor Loss Area (mm²)
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Photoreceptor loss area (mm²) will be quantified using optical coherence tomography (OCT). Measurements will be performed using a previously validated deep learning-based automated algorithm (RetInSight GA Monitor). Changes in photoreceptor loss area (mm²) will be compared between the PRP-treated eye and the fellow untreated eye.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Photoreceptor Loss Growth Rate (Square root transformed, mm/year)
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Photoreceptor loss growth rates will be calculated from square root transformed lesion areas to reduce bias related to baseline lesion size. Growth rates derived from square root transformed areas will be expressed in millimeters per year (mm/year). Growth rates will be compared between the PRP-treated eye and the fellow untreated eye.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Best-Corrected Visual Acuity
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Best-corrected visual acuity (BCVA) will be measured monocularly and binocularly at 6 meters using a Snellen chart and converted to logMAR values for analysis. Changes in BCVA will be compared between baseline and week 10, as well as between the PRP-treated eye and the fellow untreated eye.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Change in Reading Performance
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Reading performance will be assessed binocularly using the MNREAD reading test. Parameters include reading acuity (logMAR), critical print size (logMAR), maximum reading speed (words per minute), and reading accessibility index. Changes will be evaluated between baseline and week 10.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Change in Multifocal Electroretinography P1-Wave Amplitude
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Multifocal electroretinography (mfERG) P1-wave amplitude (nV) will be analyzed across retinal rings. Changes from baseline to week 10 and differences between treated and fellow untreated eyes will be evaluated.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Change in Multifocal Electroretinography P1-Wave Implicit Time
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Multifocal electroretinography (mfERG) P1-wave implicit time (ms) will be analyzed across retinal rings. Changes from baseline to week 10 and differences between treated and fellow untreated eyes will be evaluated.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Change in Vision-Related Quality of Life (NEI-VFQ-25 Score)
Time Frame: Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)
Vision-related quality of life will be assessed using the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). Subscale scores and overall composite score will be compared between baseline and week 10.
Baseline (Week 0) to Week 10 (2 weeks after the third PRP injection)

Collaborators and Investigators

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

Sponsor

Marmara University Pendik Training and Research Hospital

Investigators

  • Principal Investigator: Nimet Zeynep Tıraş, Medical Doctor, Marmara University Faculty of Medicine, Department of Ophthalmology

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)

July 1, 2024

Primary Completion (Actual)

October 30, 2024

Study Completion (Actual)

October 30, 2024

Study Registration Dates

First Submitted

February 9, 2026

First Submitted That Met QC Criteria

February 17, 2026

First Posted (Actual)

February 24, 2026

Study Record Updates

Last Update Posted (Actual)

February 24, 2026

Last Update Submitted That Met QC Criteria

February 17, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 09.2024.656

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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