Utilization of Residual Donor Tissue for Regrafting in Bullous Keratopathy After Corneal Transplantation

September 28, 2026 updated by: Zhongshan Ophthalmic Center, Sun Yat-sen University

Postoperative endothelial cell loss following Descemet stripping endothelial keratoplasty (DSEK) remains a well-recognized clinical concern, with long-term follow-up demonstrating approximately 50% reduction in endothelial cell density by 5 years. Compounding this challenge, the critical shortage of corneal donors has severely limited the expansion of corneal transplantation programs in developing countries. In conventional penetrating keratoplasty, only the central 7-mm optical zone is typically harvested, whereas the peripheral donor tissue-whose endothelial cells are believed to exhibit superior viability-is routinely discarded.

To address these limitations, we describe the first-in-human use of three residual peripheral donor tissue segments, obtained after conventional keratoplasty, which were combined to perform corneal endothelial transplantation. This innovative approach substantially enhanced donor tissue utilization. Postoperatively, the patient achieved sustained corneal transparency with visual acuity improving from 20/500 to 20/50. Notably, the intersegmental gaps resolved progressively over time.

Extending this proof-of-concept case, we subsequently investigated the long-term stability and safety of residual donor tissue endothelial keratoplasty for bullous keratopathy, with comprehensive evaluation of postoperative visual acuity, intraocular pressure, corneal endothelial cell density, and refractive outcomes. This study aims to establish evidence-based support for the safety and efficacy of utilizing residual graft tissue in corneal endothelial transplantation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Guangdong
      • Guangzhou, Guangdong, China, 510070
        • State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University
        • Contact:

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with bullous keratopathy of various etiologies, with a corneal thickness of ≥650 μm, refractory to medical treatment.
  • Aged ≥18 years.
  • The subject or their legally authorized guardian voluntarily consents to participate in this study and signs the informed consent form, with good compliance and willingness to attend follow-up visits.

Exclusion Criteria:

  • Loss of vision in the fellow eye.
  • Corneal or ocular surface infection within 30 days prior to enrollment.
  • Severe dry eye, with Schirmer's test < 5 mm.
  • Concurrent diseases that may affect the transplantation or prognosis, such as advanced glaucoma or retinal diseases.
  • Ocular surface malignancy.
  • Severe cicatrizing ocular disease; conjunctival scarring with fornix shortening.
  • Recent HbA1c > 6.5%, or uncontrolled diabetes mellitus.
  • Severe impairment of vital organs, including the heart, liver, or kidneys.
  • Severe hematologic or endocrine disorders, or a history of such disorders.
  • Active autoimmune disease.
  • Current signs of infection, including fever or ongoing antibiotic therapy.
  • Psychiatric disorders.
  • Pregnant or lactating women, or women planning pregnancy within 2 years.
  • Participation in other clinical studies or trials within 3 months.
  • Subjects who lack compliance with the study or the capacity to sign the informed consent form.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Postoperative corneal thickness

To observe postoperative corneal thickness in patients with bullous keratopathy treated by endothelial keratoplasty using residual donor tissue following previous corneal transplantation.
Procedure: Endothelial keratoplasty using residual donor tissue

Endothelial keratoplasty using residual donor tissue from previous corneal transplantation

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Corneal thickness
Time Frame: Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.

Corneal thickness was measured preoperatively and postoperatively using an iVue OCT (OPTOVUE) or another OCT instrument, and the changes were compared.
Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Best-corrected visual acuity (BCVA)
Time Frame: Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.

Preoperative and postoperative visual acuity was assessed using the ETDRS chart.
Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.
Spherical equivalent (SE)
Time Frame: Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.

Preoperative and postoperative SE was measured using a phoropter and an autorefractor, and differences before and after surgery as well as between the two groups were compared.
Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.
Corneal edema and opacity
Time Frame: Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.

The degree of corneal edema and opacity was examined by slit-lamp microscopy.
Preoperatively and at postoperative day 1; at 1 and 2 weeks; and at 1, 2, 3, 6, and 12 months.
Corneal endothelial cell count
Time Frame: At postoperative day 1 and at 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months.

Postoperative corneal endothelial cell density was measured using laser confocal microscopy (Heidelberg Engineering, Germany) or a corneal endothelial specular microscope, and changes were compared.
At postoperative day 1 and at 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months.
Donor graft detachment
Time Frame: At postoperative day 1 and at 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months.

Graft adhesion/apposition was evaluated by slit-lamp microscopy and OCT.
At postoperative day 1 and at 1 week, 2 weeks, 1 month, 2 months, 3 months, 6 months, and 12 months.
Intraocular pressure (IOP)
Time Frame: Preoperatively and at 1, 3, 6, and 12 months postoperatively.

Preoperative and postoperative IOP was measured using a non-contact tonometer.
Preoperatively and at 1, 3, 6, and 12 months postoperatively.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Zhongshan Ophthalmic Center, Sun Yat-sen 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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 17, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 18, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 18, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 28, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 28, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 2, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 2, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026KYPJ038

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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