Plain English Summary
Background and study aims
Glaucoma drainage devices (GDD) are frequently implanted in patients with glaucoma, most of the tube is implanted in the anterior chamber. However, this implantation causes problems in the cornea. To avoid this, many surgeons implant tubes in the posterior chamber (between the iris and the intraocular lens), although this is cumbersome and a more difficult surgical technique. In this study, a new method of inserting the tube was investigated for safety.
Who can participate?
Patients with glaucoma who require GDD tube implantation.
What does the study involve?
The study consists of teaching an easy, simple and effective method to implant GDD tubes in the posterior chamber. This surgical technique was designed and published by us about 10 years ago but is now modified.
What are the possible benefits and risks of participating?
The main benefits are to facilitate the surgical technique, shorten the time of the surgery and avoid intra and postoperative complications. The risks are scarce and not due to the surgical manoeuvre but to the evolution of glaucoma.
Where is the study run from?
Clínica Universidad de Navarra, Pamplona, Spain.
When is the study starting and how long is it expected to run for?
January 2009 to January 2019.
Who is funding the study?
Universidad de Navarra, Spain.
Who is the main contact?
Prof. Javier Moreno-Montañés,
Surgical technique for ab interno implantation of glaucoma drainage devices (GDD) in the posterior chamber in patients with glaucoma
The hypothesis of our study is that it is easier and more comfortable for a surgeon to insert a tube behind the iris (therefore without direct vision) by traction of the tube from inside the eye through a prolene suture compared to the usual method.
Study approved by the ethical committee of the University of Navarra (Edificio Central, Campus universitario, 31009 Pamplona, Navarra, Spain; +34 948296500; firstname.lastname@example.org), ref: 2019.062
Primary study design
Secondary study design
Patient information sheet
No participant information sheet available
Implantation of the glaucoma drainage tube into the posterior chamber using a 10/0 prolene needle. The new technique begins with the passage of one of two straight needles existing at each end of a 10-0 Polypropylene suture through the GDD tube. A 23-gauge needle then is inserted at an angle 180° away and passed from the anterior to the posterior chamber and finally through the sclera. The two suture straight needles from the 10-0 Polypropylene suture are positioned in the lumen of the 23-gauge needle. The 23-gauge needle is then extracted from the eye by passing the 2 needles through the lumen. The suture remains inside the posterior chamber, and the tube is inserted into the posterior chamber by pulling on the suture from the other side.
The participants included in this study were patients who had to be operated on for glaucoma surgery using a Glaucoma Drainage Device (GDD). They were therefore patients with glaucoma with a surgical indication. These patients signed informed consent. The duration of the follow-up was as long as possible until the study was prepared for publication.
Primary outcome measure
Adequate and correct placement of the tube and ease of surgical technique assessed by the surgeon who performed the operation one day after the procedure.
Secondary outcome measures
1. Intraocular pressure control after the follow-up period measured at all postoperative visits with a Goldmann tonometer.
2. Presence of complications following surgery.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Patients with advanced glaucoma who have undergone drainage device implantation
Target number of participants
Participant exclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Clínica Universidad de Navarra
Avenida Pío XII, 36
Universidad de Navarra
University of Navarra
Funding Body Type
private sector organisation
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Publication in BMC Ophthalmology as a Technical Advance
IPD sharing statement:
All data generated or analysed during this study will be included in the subsequent results publication
Intention to publish date
Participant level data
Basic results (scientific)