Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05904613 |
| Other study ID # |
RETROXEN |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
October 9, 2018 |
| Est. completion date |
December 31, 2021 |
Study information
| Verified date |
June 2023 |
| Source |
Groupe Hospitalier Paris Saint Joseph |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Glaucoma is a blinding optic neuropathy affecting 80 million people worldwide, with primary
open-angle glaucoma being the most common etiology. Today, the therapeutic arsenal includes
drug-based hypotonizing treatments, lasers and surgery. In France, the most common surgical
techniques are trabeculectomy and deep non-perforating sclerectomy (SPNP). The principle
behind these filtering techniques is to lower intraocular pressure (IOP) by creating an
escape route for aqueous humor from the anterior chamber (AC) of the eye into the
subconjunctival space, creating a filtration bubble (FB).
A new minimally invasive treatment option has been developed to limit intra- and
post-operative complications. This new technique is based on an ab interno approach, with
implantation through the anterior chamber of a 6mm-long, 45µm-lumen collagen tube called
XEN®. As a result, there is no dissection of the conjunctivotenone planes, as is the case in
traditional surgery.
Since June 2017, surgeons have been able to use the XEN® technique in the ophthalmology
department at GHPSJ.
Today, no study has yet assessed endothelial cell loss more than 2 years after this surgery.
Indeed, the presence of an anterior chamber device of any type can be associated with
endothelial cell loss, which increases over time well after the surgical procedure, and may
require removal of the device several years after surgery.
Recent studies have investigated peripheral endothelial cell loss with other drainage
systems. They show a significant decrease in peripheral endothelial cell density in relation
to the implant placed in the anterior chamber. The aim of this study is to evaluate central
and peripheral endothelial cell density in the long term after XEN® placement. At the visit
more than 3 years after XEN® implant placement, IOP and pachymetry measurements were taken,
along with a measurement of peripheral and central endothelial cell density. Corneal
peripheral endothelial cell density is measured on the different quadrants of the treated
eye, as well as on the controlateral eye. Measurements will be made for each eye for patients
undergoing surgery on both eyes.
Description:
Glaucoma is a blinding optic neuropathy affecting 80 million people worldwide, with primary
open-angle glaucoma being the most common etiology. Today, the therapeutic arsenal includes
drug-based hypotonizing treatments, lasers and surgery. In France, the most common surgical
techniques for glaucoma are trabeculectomy and deep non-perforating sclerectomy (SPNP). These
are two filtering techniques designed to lower intraocular pressure (IOP) by creating an
escape route for aqueous humor from the anterior chamber (AC) of the eye into the
subconjunctival space, creating a filtering bubble (FB). They can be performed alone, or at
the same time as cataract surgery. The short-term complications encountered with these
techniques are early hypotony and its attendant complications (choroidal detachment,
hypotonic maculopathy, haemorrhages, etc.), the most frequent cause of which is conjunctival
leakage of the bubble. In the medium term, tension rises with a deep anterior chamber are
evidence of an over-tight scleral flap, which may require suture lysis. Finally, problems of
excessive conjunctivotenone scarring affect 25% to 30% of patients, and are responsible for
the majority of late tension increases. In the longer term, the most frequent complication is
cataract. The rarest but most serious complication is infection of the BF, which occurs more
frequently when the walls of the BF are ischemic or perforated. It can be complicated by
endophthalmitis, which can lead to irreversible loss of visual acuity.
A new minimally invasive treatment option has been developed to limit intra- and
post-operative complications. This new technique is based on an ab interno approach, with
implantation through the anterior chamber of a 6mm-long, 45µm-lumen collagen tube called
XEN®. There is no need to dissect the conjunctivotenon planes, as is the case with
traditional surgery.
The geometry of the XEN® implant has been designed to prevent major hypotonia. This new
technique avoids the complications associated with conjunctival dissection, while being
faster and offering a standardized surgical technique. ). Today, XEN® implant placement is
used in simple surgery or combined with cataract surgery for open-angle glaucoma, incipient
to moderate, associated or not with a cataract, progressive and unbalanced under local
hypotonizing treatment.
Since June 2017, surgeons have been able to use the XEN® technique in the GHPSJ ophthalmology
department.
To date, no study has assessed endothelial cell loss more than 2 years after this surgery.
Indeed, the presence of an anterior chamber device of any type may be associated with
endothelial cell loss that increases over time, well after the operation, and may require
removal of the device several years after the operation. One study showed that the
microinvasive ab interno Alcon Cypass® device (a device similar to XEN®) caused significant
endothelial cell loss 2 years after device implantation, and was unacceptable compared with
conventional glaucoma surgery. The damage was proportional to the surface area of the implant
in the anterior chamber, and led to the immediate withdrawal of the device from the market.
Recent studies have examined peripheral endothelial cell loss with other drainage systems.
They show a significant reduction in peripheral endothelial cell density in relation to the
implant placed in the anterior chamber. Intracameral devices appear to have an impact on
endothelial integrity. To date, no study has assessed long-term central and peripheral
endothelial cell density after XEN® placement.
At the visit more than 3 years after XEN® implantation, intraocular pressure (IOP) is
measured with a Goldmann applanation tonometer, pachymetry with a NIDEK automatic
refractometer and central and peripheral endothelial cell density with a NIDEK specular
microscope. Peripheral corneal endothelial cell density is measured on the various ocular
quadrants. The same measurements are taken on the controlateral eye. Patients undergoing
surgery on both eyes receive the same measurements for each eye.
