Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2020 Sep;127(9):1162-1169.
doi: 10.1016/j.ophtha.2020.02.034. Epub 2020 Mar 4.

Visual Field Outcomes in the Tube Versus Trabeculectomy Study

Swarup S Swaminathan  1 , Alessandro A Jammal  2 , Helen L Kornmann  3 , Philip P Chen  4 , William J Feuer  1 , Felipe A Medeiros  2 , Steven J Gedde  5 ; Tube Versus Trabeculectomy Study Group
Affiliations
Randomized Controlled Trial

Visual Field Outcomes in the Tube Versus Trabeculectomy Study

Swarup S Swaminathan et al. Ophthalmology. 2020 Sep.

Abstract

Purpose: To describe visual field (VF) outcomes in the Tube Versus Trabeculectomy (TVT) Study.

Design: Cohort analysis of patients in a multicenter randomized clinical trial.

Participants: A total of 122 eyes of 122 patients, with 61 eyes in both the tube shunt and trabeculectomy groups.

Methods: The TVT Study is a multicenter randomized clinical trial comparing the safety and efficacy of tube shunt surgery (350-mm2 Baerveldt implant) and trabeculectomy with mitomycin C (MMC) (0.4 mg/ml for 4 minutes) in patients with previous cataract or glaucoma surgery. Enrolled patients underwent perimetry at baseline and annual follow-up visits. The VFs were included if the false-positive rate was ≤20% and false-negative rate was ≤35%. The VFs were excluded if visual acuity <20/400 or loss of ≥2 Snellen lines from baseline was attributed to an etiology other than glaucoma. Longitudinal linear mixed-effects models with best linear unbiased predictions (BLUPs) were applied to estimate rates of change in mean deviation (MD) for each treatment group.

Main outcome measure: Rate of MD change during follow-up period.

Results: A total of 436 reliable VFs were analyzed, with an average of 3.6 VFs per eye. Baseline MD was -13.07 ± 8.4 decibels (dB) in the tube shunt group and -13.18 ± 8.2 dB in the trabeculectomy group (P = 0.99). The rate of change in MD was -0.60 dB/year in the tube group and -0.38 dB/year in the trabeculectomy group (P = 0.34). The 95% confidence intervals for the rates of MD change were -0.77 to -0.44 dB/year in the tube group and -0.56 to -0.20 dB/year in the trabeculectomy group. No significant difference in MD slope was seen when patients were categorized by percentage of visits with intraocular pressure (IOP) <18 mmHg or by average IOP. Univariable and multivariable risk factor analyses identified history of diabetes, elevated IOP, and worse MD as baseline factors associated with more rapid VF loss.

Conclusions: Slow rates of VF loss were observed after randomized surgical treatment in the TVT Study, but no significant difference in the rate of VF loss was seen after tube shunt implantation and trabeculectomy with MMC. Patients with diabetes, higher IOP, and more severe VF loss at baseline were at higher risk for VF progression.

PubMed Disclaimer

Conflict of interest statement

No conflicting relationship exists for any author.

Figures

Figure 1.
Figure 1.
Histogram demonstrating the distribution of rate of change in mean deviation (MD) in the tube shunt and trabeculectomy groups. Both groups had a similar distribution.
See this image and copyright information in PMC

References

    1. Gedde SJ, Schiffman JC, Feuer WJ, et al. The tube versus trabeculectomy study: design and baseline characteristics of study patients. Am J Ophthalmol 2005;140(2):275–87. - PubMed
    1. Gedde SJ, Schiffman JC, Feuer WJ, et al. Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up. Am J Ophthalmol 2012;153(5):789–803 e2. - PMC - PubMed
    1. Gedde SJ, Herndon LW, Brandt JD, et al. Surgical complications in the Tube Versus Trabeculectomy Study during the first year of follow-up. Am J Ophthalmol 2007;143(1):23–31. - PubMed
    1. Saheb H, Gedde SJ, Schiffman JC, et al. Outcomes of glaucoma reoperations in the Tube Versus Trabeculectomy (TVT) Study. Am J Ophthalmol 2014;157(6):1179–89 e2. - PMC - PubMed
    1. Rauscher FM, Gedde SJ, Schiffman JC, et al. Motility disturbances in the tube versus trabeculectomy study during the first year of follow-up. Am J Ophthalmol 2009;147(3):458–66. - PMC - PubMed

Publication types