PENTACON Trial: Partial ENdothelial Trepanation in Addition to Anterior Lamellar Keratoplasty in keratoCONus (PENTACON)
Keratoconus is a progressive, non-inflammatory corneal disease in which irregular refractive properties of the cornea result in loss of visual acuity. Treatment is aimed at improving vision, principally using (rigid) contact lenses. With progression of the disease non-correctable refractive abnormalities and/or corneal scars arise. For these advanced stages of keratoconus, a corneal transplant is the only treatment modality.
New surgical grafting modalities have been developed to create partial thickness grafts, according to the location of corneal pathology. For keratoconus, transplanting only the anterior corneal lamellae lowers long-term graft rejection rates. We utilize a method to enhance the safety of the grafting procedure while better visual outcomes are expected.
To investigate the additional value of partial endothelial trepanation (PET) in an anterior lamellar keratoplasty (ALKP) procedure in terms of efficacy and safety in patients with keratoconus.
A randomized controlled interventional trial
Patients over 18 years old with keratoconus in whom contact lens correction is unsuccessful and who are not suitable for corneal crosslinking.
Patients will be randomly assigned to corneal grafting techniques; partial endothelial trepanation in addition to an anterior lamellar keratoplasty (i.e. the PET group) or a regular ALKP procedure.
Risk of per-operative perforation. Secondary, factors contributing to treatment safety and efficacy.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness:
There is no extra burden or risk associated with participation in this study. All measurements are part of normal clinical practice. Adequate experience is available with both surgical techniques. Study participation has no effect on donor selection. If partial endothelial trepanation (PET) is associated with lower complication rates and better visual outcomes, this might be beneficial in terms of morbidity.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Pentacon Trial: Partial ENdothelial Trepanation in Addition to Anterior Lamellar Keratoplasty in keratoCONus. A Prospective Multicenter Randomized Controlled Trial|
- Peroperative corneal perforation [ Time Frame: During Surgery. From start to closure of surgical procedure approx. 2h ]Peroperative corneal perforation is the biggest drawback of currently utilized grafting procedures (ALKP, 20-30%). Our new technique is believed to be safer, by reducing the number of corneal perforations during surgery. Corneal perforation necessitates converting the procedure to a full-thickness graft with a less favourable long term rejection profile.
- Best corrected visual acuity one year post op [ Time Frame: One year post-op ]To determine treatment efficacy visual acuity is assessed one year post-op.
- Manifest refraction one year post op [ Time Frame: One year post-op ]Manifest refraction can be grossly altered after corneal grafting procedures. To assess this effect, a manifest refraction one year post-op is obtained.
- Contact lens use (soft/rigid/scleral) or spectacle use [ Time Frame: one year post-op ]To assess the dependency on visual aids after corneal grafting. Residual irregular post-op corneal abnormalities can necessitate (rigid) contact lens wear.
- Self-rated improvement questionnaire [ Time Frame: One year post-op ]To assess patient satisfaction with treatment outcomes, such as visual acuity, residual refraction etc. This will be measured using the Visual Functioning Questionnaire-25 (Dutch edition).
- Corneal endothelial function one year post op [ Time Frame: One year post-op ]To assess corneal endothelial function as a measurement for corneal damage sustained during grafting procedure. Endothelial function plays a role in long term corneal decompensation issues.
- Graft rejection rate [ Time Frame: During one-year follow up period ]Lamellar grafting has proven to lower graft rejection rates. Any graft rejection (endothelial, stromal or epithelial) will be recorded en reported.
|Study Start Date:||March 2011|
|Study Completion Date:||May 2015|
|Primary Completion Date:||May 2015 (Final data collection date for primary outcome measure)|
Partial endothelial trepanation in addition to anterior lamellar keratoplasty.
The endothelium en Descemet are paracentrally and circular loosened, but some tissue bridges are left in place. This 'island' is able to mould to the healthy donor curvature.
Partial Endothelial Trepanation in addition to an anterior lamellar keratoplasty
Other Name: Busin
Active Comparator: DALK
Conventional DALK grafting procedure where the Big Bubble technique is used according to Anwar et al.
Conventional DALK grafting procedure, with Big Bubble technique according to Anwar et al.
Other Name: ALK
Show Detailed Description
Please refer to this study by its ClinicalTrials.gov identifier: NCT01145937
|Breda, Netherlands, 4819 EV|
|Hoorn, Netherlands, 1620 AR|
|UMCN St. Radboud|
|Nijmegen, Netherlands, 6500HB|
|Rotterdam Eye Hospital|
|Rotterdam, Netherlands, 3000 LM|
|University Medical Center Utrecht|
|Utrecht, Netherlands, 3508 GA|
|Principal Investigator:||Allegonda Van der Lelij, MD PhD||UMC Utrecht|