None listed
Conditions
Brief summary
The study objective is to determine the safety and efficacy of a new shunt that has been developed to eliminate some of the disadvantages of current shunts in the treatment of refractory/severe and moderate glaucoma in severity. It is hypothesized that this new device will lower intraocular pressure with nil to diminished frequency of commonly encountered problems with the present day aqueous shunts. Treatment of glaucoma aims at lowering the eye pressure by medication, laser or surgical procedure. The traditional first line surgery is trabeculectomy, which involves creating a new drainage hole that would result in the formation of a bleb. This would achieve lowering of the eye pressure. If trabeculectomy fails, then the implantation of glaucoma drainage device (GDD) would be considered. Existing GDDs include Baerveldt, Molteno, Ahmed and Krupin. Although aqueous shunts have traditionally been used as the last treatment resort, a recent study with 5 years data has been published and demonstrated that the performance of shunts is comparable to that of trabeculectomy.
Interventions
Under general anesthesia, peritomy and blunt dissection are done. The Paul Glaucoma Implant (PGI) is checked for patency and a rectangular pericardial patch graft (Tutopatch®) is placed on top of the plate posterior to the valve before the plate is sutured in place 8.5-10mm away from the limbus using Nylon 8/0. Anterior chamber paracentesis is done.
If it is a combined cataract and glaucoma surgery, the surgeon proceeds with phacoemulsification with intraocular lens implant.
The pupil is the
Under general anesthesia, peritomy and blunt dissection are done. The Paul Glaucoma Implant (PGI) is checked for patency and a rectangular pericardial patch graft (Tutopatch®) is placed on top of the plate posterior to the valve before the plate is sutured in place 8.5-10mm away from the limbus using Nylon 8/0. Anterior chamber paracentesis is done. If it is a combined cataract and glaucoma surgery, the surgeon proceeds with phacoemulsification with intraocular lens implant. The pupil is then miosed and the anterior chamber is reformed with viscoelastic. The tube is then cut to desired length and the track for the tube towards the anterior chamber is created. The tube is then fixed in place with interrupted sutures and covered with Tutopatch® using a fibrin sealant (Tisseel VH S/D, Baxter Healthcare Pte Ltd). Approximately 0.3mL of cross-linked viscoelastic is then injected around & above the plate before closing the conjunctiva. Subconjunctival injection of Gentamycin 20mg with Dexamethasone 4mg is then given at the end of the procedure. The approximate time commitment of the intervention will be around 3 to 4 hours. The intervention will be administered by surgeons
Sponsors
National University Hospital (S) Pte Ltd
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
21 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
• Age between 21 - 80 years old • Eyes with severe, refractory glaucoma defined as IOP exceeding 21 mmHg on maximal tolerated medical therapy with any of the following: i) failed 1 or more incisional glaucoma surgeries (glaucoma filtering surgery, trabeculectomy, tube shunt); ii) failed 1 or more cilioablative procedures(e.g. cryotherapy, cyclodiode therapy); iii) have any other conditions (conjunctival scarring uveitis) in which conventional incisional glaucoma surgery like trabeculectomy would be more likely to fail) • Eyes with moderate glaucoma defined as eyes with glaucomatous visual field defects not affecting the central 5 degrees of fixation, requires more than 1 IOP-lowering eyedrops and has visually-significant cataract requiring cataract surgery • Maximally-tolerated medicated IOP at two preoperative visits of greater 21 mmHg and greater than or equal to 35 mmHg • Area of free, healthy and mobile conjunctiva in the targeted quadrant
Exclusion criteria
• Unwilling or unable to give consent, or unable to return for scheduled visits. • Fellow eye VA worse than 6/60. • other significant ocular disease, except cataract • active ocular infection or inflammation • expected ocular surgery in next 12 months • no suitable quadrant for tube implant • systemic corticosteroid therapy > 5 mg/day prednisone • intolerance to eye exams • mental impairment interfering with consent or compliance • pregnant or nursing women • known sensitivity to anticipated medications used at surgery • significant co-morbid disease • concurrent enrolment in another drug or device study
Outcome results
None listed