Pupillary Block After DMEKNCT07577635
Impact of Iridotomy/Iridectomy Size on Postoperative Pupillary Block and Dysphotopsia Following DMEK
An observational study of Pupillary Block After DMEK and Laser Iridotomy / Surgical Iridectomy, run by University of Leipzig.
Trial summary
Descemet membrane endothelial keratoplasty (DMEK) is the standard surgical treatment for corneal endothelial disorders. A postoperative pupillary block may occur despite routine preoperative laser iridotomy or intraoperative surgical iridectomy. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Pupillary Block After DMEK, Laser Iridotomy / Surgical Iridectomy, Dysphotopsia
- What is being tested?
- Anterior Segment Optical Coherence Tomography (AS-OCT) and Dysphotopsia Questionnaire
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 1 Jun 2026to 1 Jul 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Adult patients undergoing Descemet membrane endothelial keratoplasty (DMEK) for corneal endothelial disease at the Department of Ophthalmology, University Hospital Leipzig, in whom a preoperative laser iridotomy or intraoperative surgical iridectomy is performed as part of standard care.
Who may be able to join
- Adults aged ≥ 18 years
- Patients undergoing Descemet membrane endothelial keratoplasty (DMEK) at the Department of Ophthalmology, University Hospital Leipzig
- Preoperative Nd:YAG laser iridotomy or intraoperative surgical iridectomy performed as part of standard care
- Ability to provide written informed consent
- Willingness to complete the postoperative dysphotopsia questionnaire
Who cannot join
- Inability to provide informed consent or refusal to participate
- Pre-existing surgical iridectomy
- Missing or incomplete preoperative or postoperative anterior segment OCT data
- Active anterior uveitis or panuveitis at the time of surgery
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Descemet membrane endothelial keratoplasty (DMEK) is the standard surgical treatment for corneal endothelial disorders. A postoperative pupillary block may occur despite routine preoperative laser iridotomy or intraoperative surgical iridectomy. Insufficient size or incomplete patency of the iridotomy/iridectomy (IT) may contribute to this complication, while excessively large openings may be associated with postoperative dysphotopsia. This prospective observational study investigates the association between IT size measured by anterior segment optical coherence tomography (AS-OCT) and the occurrence of postoperative pupillary block and dysphotopsia after DMEK.
Read the detailed description
Descemet membrane endothelial keratoplasty (DMEK) represents the current standard procedure for surgical treatment of corneal endothelial diseases. During DMEK, a gas bubble is placed in the anterior chamber to attach the graft. In rare cases, this may lead to postoperative pupillary block with acute intraocular pressure elevation and severe pain. To prevent this complication, preoperative Nd:YAG laser iridotomy or intraoperative surgical iridectomy is routinely performed. Nevertheless, pupillary block continues to occur in a subset of patients.
One potential cause is an iridotomy or iridectomy that is too small or not fully patent, which may be misclassified as open on slit-lamp examination. Conversely, large iridotomy openings may induce postoperative dysphotopsia. Currently, no standardized recommendations exist regarding optimal IT size in the setting of DMEK, and systematic data correlating IT size with pupillary block and dysphotopsia are lacking.
This study is designed as a prospective, monocentric, non-interventional observational study. Adult patients undergoing DMEK at the Department of Ophthalmology, University Hospital Leipzig, with either preoperative laser iridotomy or intraoperative surgical iridectomy are invited to participate. AS-OCT imaging of the iris is performed preoperatively or postoperatively as an additional study-related diagnostic procedure to quantify IT size. All surgical procedures and clinical follow-up examinations remain unchanged from standard care.
Postoperatively, clinical outcomes including the occurrence of pupillary block are documented during routine follow-up. New postoperative dysphotopsia is assessed using a structured, German-adapted dysphotopsia questionnaire based on the instrument described by Vera et al., administered after resolution of the intracameral gas bubble and corneal edema.
The primary endpoint is the occurrence of postoperative pupillary block after DMEK. The secondary endpoint is the occurrence and severity of new postoperative dysphotopsia. A total of 100 consecutive patients will be included over a planned study period of 12 months. The study aims to explore associations between IT size and postoperative complications in order to improve perioperative risk stratification in DMEK surgery.
- Conditions
- Pupillary Block After DMEK, Laser Iridotomy / Surgical Iridectomy, Dysphotopsia, Descemet Membrane Endothelial Keratoplasty (DMEK)
- Being tested
- Anterior Segment Optical Coherence Tomography (AS-OCT), Dysphotopsia Questionnaire
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anterior Segment Optical Coherence Tomography (AS-OCT)Diagnostic test
Additional anterior segment OCT imaging of the iris to quantify the size and patency of the iridotomy or iridectomy in DMEK patients, performed as a non-invasive, contact-free study-related diagnostic procedure alongside routine clinical examinations.
Dysphotopsia QuestionnaireOther
Structured patient questionnaire to assess occurrence and severity of new postoperative dysphotopsia after DMEK.
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of postoperative pupillary block after DMEK
Pupillary block is defined as intraocular pressure >25 mmHg with a centrally deep anterior chamber and partial or complete peripheral angle closure.
Measured: Within the first five postoperative days, including day 0 (date of surgery)
Secondary outcomes (1)
Occurrence and severity of postoperative dysphotopsia
Assessed using a structured dysphotopsia questionnaire based on the instrument by Vera et al., providing an ordinal severity score.
Measured: between 2 weeks and 1 year postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 May 2026
- Study start1 Jun 2026 (estimated)
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pupillary Block After DMEKStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Leipzig
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Christian Girbardt, University of Leipzig
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07577635
- Sponsor's protocol ID
- DMEK-YAG
- Status last verified
- Jul 2026
- First submitted
- 26 Jan 2026
- Last updated
- 2 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Iridotomy/Iridectomy Size on Postoperative Pupillary Block and Dysphotopsia Following DMEK
- ClinicalTrials.gov ID
- NCT07577635
- Acronym / sponsor ID
- DMEK-YAG
- Conditions
- Pupillary Block After DMEK, Laser Iridotomy / Surgical Iridectomy, Dysphotopsia, Descemet Membrane Endothelial Keratoplasty (DMEK)
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University of LeipzigUniversity, hospital or other
- Study start
- 1 Jun 2026 (estimated)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jul 2027 (estimated)
- First posted
- 11 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Descemet membrane endothelial keratoplasty (DMEK) is the standard surgical treatment for corneal endothelial disorders. A postoperative pupillary block may occur despite routine preoperative laser iridotomy or intraoperative surgical iridectomy. Insufficient size or incomplete patency of the iridotomy/iridectomy (IT) may contribute to this complication, while excessively large openings may be associated with postoperative dysphotopsia. This prospective observational study investigates the association between IT size measured by anterior segment optical coherence tomography (AS-OCT) and the occurrence of postoperative pupillary block and dysphotopsia after DMEK.
Detailed description
Descemet membrane endothelial keratoplasty (DMEK) represents the current standard procedure for surgical treatment of corneal endothelial diseases. During DMEK, a gas bubble is placed in the anterior chamber to attach the graft. In rare cases, this may lead to postoperative pupillary block with acute intraocular pressure elevation and severe pain. To prevent this complication, preoperative Nd:YAG laser iridotomy or intraoperative surgical iridectomy is routinely performed. Nevertheless, pupillary block continues to occur in a subset of patients.
One potential cause is an iridotomy or iridectomy that is too small or not fully patent, which may be misclassified as open on slit-lamp examination. Conversely, large iridotomy openings may induce postoperative dysphotopsia. Currently, no standardized recommendations exist regarding optimal IT size in the setting of DMEK, and systematic data correlating IT size with pupillary block and dysphotopsia are lacking.
This study is designed as a prospective, monocentric, non-interventional observational study. Adult patients undergoing DMEK at the Department of Ophthalmology, University Hospital Leipzig, with either preoperative laser iridotomy or intraoperative surgical iridectomy are invited to participate. AS-OCT imaging of the iris is performed preoperatively or postoperatively as an additional study-related diagnostic procedure to quantify IT size. All surgical procedures and clinical follow-up examinations remain unchanged from standard care.
Postoperatively, clinical outcomes including the occurrence of pupillary block are documented during routine follow-up. New postoperative dysphotopsia is assessed using a structured, German-adapted dysphotopsia questionnaire based on the instrument described by Vera et al., administered after resolution of the intracameral gas bubble and corneal edema.
The primary endpoint is the occurrence of postoperative pupillary block after DMEK. The secondary endpoint is the occurrence and severity of new postoperative dysphotopsia. A total of 100 consecutive patients will be included over a planned study period of 12 months. The study aims to explore associations between IT size and postoperative complications in order to improve perioperative risk stratification in DMEK surgery.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Adult patients undergoing Descemet membrane endothelial keratoplasty (DMEK) for corneal endothelial disease at the Department of Ophthalmology, University Hospital Leipzig, in whom a preoperative laser iridotomy or intraoperative surgical iridectomy is performed as part of standard care.
Key inclusion criteria (5 listed)
- Adults aged ≥ 18 years
- Patients undergoing Descemet membrane endothelial keratoplasty (DMEK) at the Department of Ophthalmology, University Hospital Leipzig
- Preoperative Nd:YAG laser iridotomy or intraoperative surgical iridectomy performed as part of standard care
- Ability to provide written informed consent
- Willingness to complete the postoperative dysphotopsia questionnaire
Key exclusion criteria (4 listed)
- Inability to provide informed consent or refusal to participate
- Pre-existing surgical iridectomy
- Missing or incomplete preoperative or postoperative anterior segment OCT data
- Active anterior uveitis or panuveitis at the time of surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Anterior Segment Optical Coherence Tomography (AS-OCT)Additional anterior segment OCT imaging of the iris to quantify the size and patency of the iridotomy or iridectomy in DMEK patients, performed as a non-invasive, contact-free study-related diagnostic procedure alongside routine clinical examinations. | Diagnostic test | – |
| Dysphotopsia QuestionnaireStructured patient questionnaire to assess occurrence and severity of new postoperative dysphotopsia after DMEK. | Other | – |
Primary outcome
Occurrence of postoperative pupillary block after DMEK
Time frame: Within the first five postoperative days, including day 0 (date of surgery)
Pupillary block is defined as intraocular pressure >25 mmHg with a centrally deep anterior chamber and partial or complete peripheral angle closure.
1 secondary outcome
Occurrence and severity of postoperative dysphotopsia
Time frame: between 2 weeks and 1 year postoperatively
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jul 2026.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
An observational study of Pupillary Block After DMEK and Laser Iridotomy / Surgical Iridectomy, run by University of Leipzig.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 2 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Christian Girbardt, Dr. med. (+493419721650, christian.girbardt@medizin.uni-leipzig.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Occurrence of postoperative pupillary block after DMEK (time frame: Within the first five postoperative days, including day 0 (date of surgery)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2026.