View Clinical Trial (Medical Research Study)
Primary Tube Versus Trabeculectomy Study
| City: |
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Charlottesville |
| State: |
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Virginia |
| Zip Code: |
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22908 |
| Conditions: |
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Glaucoma |
| Purpose: |
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The purpose of the Primary Tube Versus Trabeculectomy (PTVT) Study is to compare the
long-term safety and efficacy of nonvalved tube shunt surgery to trabeculectomy with
mitomycin C in eyes that have not had previous ocular surgery.
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| Study Summary: |
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Glaucoma surgery is indicated when further intraocular pressure (IOP) lowering is needed
despite the use of maximum tolerated medical therapy and appropriate laser treatment.
Trabeculectomy (or guarded filtration procedure) is the most frequently performed glaucoma
opertion. Eyes with previous ocular surgery and certain secondary glaucomas (e.g.
neovascular glaucoma and uveitic glaucoma) are at greater risk of trabeculectomy failure.
Wound healing modulation with antifibrotic agents, like mitomycin C (MMC) and 5-fluorouracil
(5-FU), has been shown to increase the success of glaucoma filtering surgery in high risk
eyes. The use of MMC and 5-FU has become widespread in clinical practice. The improved
efficacy of trabeculectomy with an adjunctive antifibrotic agent in high risk eyes has
prompted their use in eyes considered to be at low risk for failure. A randomized clinical
trial found similar IOP reduction and surgical complications with the intraoperative
application of MMC and 5-FU in eyes undergoing primary trabeculectomy.
Although antifibrotic agents have increased the likelihood of IOP control following glaucoma
filtering surgery, they have also increased the risk of complications. The prevalence of
bleb-related infections, bleb leaks, and bleb dysesthesia associated with a perilimbal
filtering bleb suggests the need to consider alternative surgical approaches. Favorable
results have been reported with tube shunts (or glaucoma drainage implants), and these
devices have been growing in popularity. In particular, the large surface area of the
Baerveldt glaucoma implant combined with its ease of insertion in a single quadrant offers
an advantage over other tube shunts. Similar surgical results have been reported with tube
shunts and trabeculectomy with MMC or 5-FU when studied separately in similar patient
groups. A comparable rate of serious complications has also been reported for the Baerveldt
implant and trabeculectomy with an antifibrotic agent in a retrospective study.
The Tube Versus Trabeculectomy (TVT) Study is a multicenter randomized clinical trial
comparing the safety and efficacy of tube shunt surgery using the Baerveldt glaucoma implant
and trabeculectomy with MMC in 212 patients with previous ocular surgery. Tube shunt
surgery was more likely to maintain IOP control and avoid persistent hypotony or reoperation
for glaucoma than trabeculectomy with MMC during the first year of follow-up in the TVT
Study. Tube shunt surgery and trabeculectomy with MMC produced similar IOP reduction at 1
year, but there was less need for supplemental medical therapy following trabeculectomy.
There were a large number of surgical complications during the first year of follow-up in
the TVT Study, but most were transient and self-limited. The incidence of postoperative
complications was higher following trabeculectomy with MMC than tube shunt surgery.
However, severe complications resulting in reoperation and/or vision loss occurred with
similar frequency with both surgical procedures. Vision loss occurred at a similar rate
following tube shunt surgery and trabeculectomy with MMC. Patients who experienced surgical
complications had greater vision loss than patients without complications.
The results of the TVT Study suggest the need to compare the safety and efficacy of tube
shunt surgery and trabeculectomy with MMC in patients at low risk of surgical failure,
including eyes without previous ocular surgery. The Primary Tube Versus Trabeculectomy
(PTVT) Study is a multicenter randomized clinical trial that is similar in design to the TVT
Study. Enrolled patients are randomized to undergo placement of a 350mm2 Baerveldt glaucoma
implant or trabeculectomy with MMC. Baseline characteristics of the study population will
be tabulated for each treatment group. Outcome discrimination between the two treatment
groups will include IOP, surgical complications, visual acuity, visual fields, glaucoma
reoperation, and need for supplemental medical therapy. Data will be collected at the
normal postoperative visits at 1 day, 1 week, 1 month, 3 months, 6 months, 1 year, 18
months, 2 years, 3 years, 4 years, and 5 years after surgery.
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| Criteria: |
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Inclusion Criteria:
- Age 18-85 years
- Glaucoma that is inadequately controlled on tolerated medical therapy with IOP
greater than or equal to 18 mm Hg and less than or equal to 40 mm Hg
- No previous incisional ocular surgery
Exclusion Criteria:
- Unwilling or unable to give consent, unwilling to accept randomization, or unable to
return for scheduled protocol visits
- Pregnant or nursing women
- No light perception vision
- Active iris neovascularization or active proliferative retinopathy
- Iridocorneal endothelial syndrome
- Epithelial or fibrous ingrowth
- Chronic or recurrent uveitis
- Steroid-induced glaucoma
- Severe posterior blepharitis
- Unwilling to discontinue contact lens use after surgery
- Previous cyclodestructive procedure
- Conjunctival scarring from prior ocular trauma or cicatrizing disease precluding a
superior trabeculectomy
- Functionally significant cataract
- Need for glaucoma surgery combined with other ocular procedures or anticipated need
for additional ocular surgery
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| NCT ID: |
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NCT00666237 |
| Primary Contact: |
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Study Chair
Steven J Gedde, MD
Bascom Palmer Eye Institute
Steven J Gedde, MD
Phone: 305-326-6435
Email: sgedde@med.miami.edu
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| Backup Contact: |
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Email: jschiffman@med.miami.edu
Joyce C Schiffman, MS
Phone: 305-243-5487
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| Location Contact: |
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Charlottesville, Virginia 22908
United States
Bruce Prum, MD
Phone: 434-924-2808
Email: bep2z@virginia.edu
Site Status: Recruiting |
| Data Source: |
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ClinicalTrials.gov |
| Date Processed: |
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May 24, 2013 |
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