Supine Positioning for Graft Attachment After Descemet Membrane Endothelial Keratoplasty

Study Overview
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Brief Summary
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This randomized controlled trial evaluates the efficacy and safety of postoperative supine head positioning on graft attachment after Descemet membrane endothelial keratoplasty in patients with Fuchs' endothelial corneal dystrophy (FECD).

Detailed Description
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In Descemet membrane endothelial keratoplasty (DMEK), an air or gas bubble is inserted in the anterior chamber of the eye to keep the ultrathin endothelial corneal graft attached to the patients own cornea. Supine positioning is thought to improve attachment by using the tamponade effect of the bubble. At present, it is unclear how long supine positioning is required. Positioning regimens vary between one hour to over one week. In this trial, the investigators will assess if prolonged supine positioning for 5 days improves graft attachment and long-term outcomes compared to supine positioning for 1 day.

Official Title
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Supine Positioning for Graft Attachment After Descemet Membrane Endothelial Keratoplasty: a Randomized Controlled Trial

Conditions
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Fuchs' Endothelial Dystrophy

Intervention / Treatment
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* Behavioral: Supine positioning: 5 days
* Behavioral: Supine positioning: 1 days


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of advanced Fuchs' endothelial corneal dystrophy (FECD) Indication for corneal endothelial transplantation (Descemet Membrane Endothelial Keratoplasty - DMEK) Exclusion Criteria: Other corneal diseases (i.e. corneal scars, corneal dystrophies except FECD, corneal inflammation / infection) Regular use of drugs potentially affecting the cornea (i.e. amiodarone, chloroquine, triptan, isotretinoin, use of contact lenses in past four weeks, anesthetic eye drops) Diabetes mellitus with endorgan complications) Lack of fixation during corneal tomography Bedridden

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Stratification will be performed according to the surgical procedure (DMEK alone or DMEK combined cataract surgery). Within each strata, participants will be randomized in a 1:1 ratio to 5 days (intervention) and 1 day (control) postoperative supine positioning.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 5 days supine positioning<br>Supine positioning for 5 days after DMEK with upright positioning for only 10 min every hour. | Behavioral: Supine positioning: 5 days<br>* Supine positioning for 5 days after DMEK<br>|
| Active Comparator: 1 day supine positioning followed by usual physical activity for 4 days<br>Supine positioning for 1 days after DMEK with upright positioning for only 10 min every hour. | Behavioral: Supine positioning: 1 days<br>* Supine positioning for 1 days after DMEK<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Graft attachment | Area of graft detachment, quantified from a trained and validated neural network for image segmentation of anterior segment optical coherence tomography | At two weeks after DMEK | 
| Graft attachment | Volume of graft detachment, quantified from a trained and validated neural network for image segmentation of anterior segment optical coherence tomography | At two weeks after DMEK | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rebubbling | Number of eyes with secondary injection of air after DMEK | At two weeks and 3 months after DMEK | 
| Safety of supine positioning | Adverse events (AE) and serious AEs (SAE) | At two weeks and 3 months after DMEK | 
| Subjective visual function | Subjective visual function on a scale from 0 (worse vision) to 10 (best vision) with higher scores meaning better subjective visual function | At 3, 12, and 24 months after DMEK | 
| Visual acuity | Best-corrected visual acuity to determine visual acuity in letters | At 3, 12, and 24 months after DMEK | 
| Disability glare | Straylight meter measurement to determine forward scatter in logs straylight parameter | At 3, 12, and 24 months after DMEK | 
| Graft health: endothelial cell density | Specular microscopy to determine endothelial cell density | At 3, 12, and 24 months after DMEK | 
| Graft health | Slit-lamp exam to identify signs of graft rejection | At 12, and 24 months after DMEK | 
| Patient-reported visual disability | The Visual Acuity Factor and Glare Factor of the Visual Function and Corneal Health Status (V-FUCHS) instrument. The instrument's scores are Rasch-analysis based scores expressed in logits. Participants with more difficulty have higher or more positive V-FUCHS scores. | At 3, 12, and 24 months after DMEK | 
| Corneal edema | Tomography to determine corneal edema in µm | At 2 weeks and at 3, 12, and 24 months after DMEK | 
| Corneal backscatter | Tomography to determine corneal backscatter in scatter units (SU) | At 3, 12, and 24 months after DMEK | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Neural network, Machine learning, Fuchs' endothelial corneal dystrophy, Randomized controlled trial, Descemet membrane endothelial keratoplasty, Incomplete graft attachment, Endothelial corneal graft detachment, Rebubbling (repeat injection of air or gas in the anterior chamber), Supine positioning, Postoperative posture, Anterior segment optical coherence tomography