Ignite Creation Date:
2024-05-05 @ 5:26 PM
Last Modification Date:
2024-10-26 @ 9:31 AM
Study NCT ID:
NCT00453024
Status:
UNKNOWN
Last Update Posted:
2008-05-14
First Post:
2007-03-27
Brief Title:
Imaging Ahmed Glaucoma Tubes With a Pericardial Graft and Tissue Glue or Partial-Thickness Scleral Flap and Sutures
Sponsor:
National University Hospital Singapore
Organization:
National University Hospital Singapore
Study Overview
Official Title:
Anterior Segment Optical Coherence Tomography Findings in Patients With Ahmed Glaucoma Drainage Implants With Either a Pericardial Patch Graft and Fibrin Tissue Glue or a Partial-Thickness Scleral Flap and Conventional Sutures
Status:
UNKNOWN
Status Verified Date:
2008-05
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
When implanting an Ahmed glaucoma tube a scleral flap is usually created to cover the tube and the conjunctiva is stitched back in place with nylon 10-0 sutures It is hypothesized that an equally safe or better method is using a bovine pericardial patch graft that can be secured in place over the tube with tissue glue and using tissue glue to reposition the conjunctiva in place
Detailed Description:
Glaucoma drainage devices GDD are usually reserved for cases wherein filtration surgery has failed or for difficult cases that do not respond to filtration surgery such as neovascular or uveitic glaucoma
The Ahmed Glaucoma drainage implant New World Medical Rancho CucamongaCA was introduced to the market in 19942 It has a scarab-shaped end plate made of polypropylene models S2 S3 and B1 or silicone models FP7 FP8 and FX1 Fenestrations have been added to the end plate of the silicone models Various sizes of the Ahmed drainage are available including those with a surface area of 96 mm2 S3 and FP8 or 184 mm2 S2 and FP7 while the double-plate version has a surface area of 364mm2 B1 and FX1 Aqueous humor passes from the anterior chamber through two thin membrane-like elastomer sheets that theoretically restrict flow until a pressure of greater than 8-12 mm Hg is exerted on them
In the implantation of GDD absorbable and non-absorbable sutures are used Sutures are typically used in securing the plate to the sclera securing the tube to the sclera suturing a patch graft or scleral flap over the silicone tube and for conjunctival closure Post-surgical course can be marked by discomfort depending on the type of suture used Absorbable sutures can induce inflammation with localized surface and subconjunctival fibrosis that leads to uneven conjunctival surface and excessive scarring On the other hand non-absorbable sutures can erode through tissue post-operatively Suturing the conjunctiva can cause button-holes and tears and can be the most time-intensive portion of the surgery
Fibrin glue has been used in various ophthalmic surgeries such as a sealant for perforated and preperforated corneal ulcers in mucous membrane grafts in the management of complicated hypotony and bleb leaks after trabeculectomy and for preventing immediate postoperative hypotony after glaucoma drainage implant surgery
In a paper by Kahook and Noecker published in 2006 the authors did a retrospective non-randomized case-control study that reviewed 28 cases of GDD implantations using traditional suture materials compared to 14 consecutive cases of GDD implantation using Tisseel fibrin glue Baxter AG Vienna Austria for closing the conjunctiva securing the pericardium patch graft and securing the tube to the sclera The authors concluded that Tisseel fibrin glue seems to be a safe substitute for some of the sutures used in GDD surgery and it has no impact on IOP control or complications It appears to reduce post-operative conjunctival inflammation and time of surgery
Optical coherence tomography OCT is a high-resolution non-invasive and reproducible imaging technology that was primarily developed to evaluate the retina and retina nerve fiber layer in patients with vitreo-retinal or optic nerve diseases11 Recently the anterior segment OCT AS-OCT has been developed and used to image anterior segment structures It has also been used to localize the Ex-PRESS miniature glaucoma implant in porcine eyes while the conventional OCT was used to show the anterior segment findings after non-penetrating deep sclerectomy and the filtering blebs of eyes that underwent glaucoma filtering surgery
Patients scheduled for Ahmed Tube surgery with or without lens extraction and intraocular lens implant will be recruited and randomized into two groups The first group of patients will have a pericardial patch graft covering the tube and fibrin glue will be used to attach the graft to the sclera and to close the conjunctiva The second group will have a partial- thickness scleral flap raised to cover the tube and the conjunctiva will be closed with conventional sutures
The Ahmed Glaucoma drainage implant New World Medical Rancho CucamongaCA was introduced to the market in 19942 It has a scarab-shaped end plate made of polypropylene models S2 S3 and B1 or silicone models FP7 FP8 and FX1 Fenestrations have been added to the end plate of the silicone models Various sizes of the Ahmed drainage are available including those with a surface area of 96 mm2 S3 and FP8 or 184 mm2 S2 and FP7 while the double-plate version has a surface area of 364mm2 B1 and FX1 Aqueous humor passes from the anterior chamber through two thin membrane-like elastomer sheets that theoretically restrict flow until a pressure of greater than 8-12 mm Hg is exerted on them
In the implantation of GDD absorbable and non-absorbable sutures are used Sutures are typically used in securing the plate to the sclera securing the tube to the sclera suturing a patch graft or scleral flap over the silicone tube and for conjunctival closure Post-surgical course can be marked by discomfort depending on the type of suture used Absorbable sutures can induce inflammation with localized surface and subconjunctival fibrosis that leads to uneven conjunctival surface and excessive scarring On the other hand non-absorbable sutures can erode through tissue post-operatively Suturing the conjunctiva can cause button-holes and tears and can be the most time-intensive portion of the surgery
Fibrin glue has been used in various ophthalmic surgeries such as a sealant for perforated and preperforated corneal ulcers in mucous membrane grafts in the management of complicated hypotony and bleb leaks after trabeculectomy and for preventing immediate postoperative hypotony after glaucoma drainage implant surgery
In a paper by Kahook and Noecker published in 2006 the authors did a retrospective non-randomized case-control study that reviewed 28 cases of GDD implantations using traditional suture materials compared to 14 consecutive cases of GDD implantation using Tisseel fibrin glue Baxter AG Vienna Austria for closing the conjunctiva securing the pericardium patch graft and securing the tube to the sclera The authors concluded that Tisseel fibrin glue seems to be a safe substitute for some of the sutures used in GDD surgery and it has no impact on IOP control or complications It appears to reduce post-operative conjunctival inflammation and time of surgery
Optical coherence tomography OCT is a high-resolution non-invasive and reproducible imaging technology that was primarily developed to evaluate the retina and retina nerve fiber layer in patients with vitreo-retinal or optic nerve diseases11 Recently the anterior segment OCT AS-OCT has been developed and used to image anterior segment structures It has also been used to localize the Ex-PRESS miniature glaucoma implant in porcine eyes while the conventional OCT was used to show the anterior segment findings after non-penetrating deep sclerectomy and the filtering blebs of eyes that underwent glaucoma filtering surgery
Patients scheduled for Ahmed Tube surgery with or without lens extraction and intraocular lens implant will be recruited and randomized into two groups The first group of patients will have a pericardial patch graft covering the tube and fibrin glue will be used to attach the graft to the sclera and to close the conjunctiva The second group will have a partial- thickness scleral flap raised to cover the tube and the conjunctiva will be closed with conventional sutures
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None