An observational study in Pupillary Block After DMEK, Laser Iridotomy / Surgical Iridectomy and Dysphotopsia, sponsored by University of Leipzig. Not yet recruiting. Per ClinicalTrials.gov, last updated 2026-07-02.
Sponsored by University of Leipzig · Observational
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.
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.
University of Leipzig is the lead sponsor of 148 studies on the registry; 25 are open to participants now.
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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.
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Exclusion Criteria:
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Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Structured patient questionnaire to assess occurrence and severity of new postoperative dysphotopsia after DMEK.
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.
Time frame: Within the first five postoperative days, including day 0 (date of surgery)
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.
Time frame: between 2 weeks and 1 year postoperatively
No study locations are listed for this record.
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Jun 2026; primary completion for Jan 2027, 7 months later.
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This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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