Treatment Outcomes in the Tube Versus Trabeculectomy Study...

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Treatment Outcomes in the Tube VersusTrabeculectomy Study After One Year

of Follow-up

STEVEN J. GEDDE, MD, JOYCE C. SCHIFFMAN, MS, WILLIAM J. FEUER, MS,LEON W. HERNDON, MD, JAMES D. BRANDT, MD, DONALD L. BUDENZ, MD, MPH,

AND THE TUBE VERSUS TRABECULECTOMY STUDY GROUP

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PURPOSE: To report one-year results of the Tubeersus Trabeculectomy (TVT) Study.DESIGN: Multicenter randomized clinical trial.METHODS: SETTING: 17 Clinical Centers. STUDY POPU-

ATION: Patients 18 to 85 years of age who had previousrabeculectomy and/or cataract extraction with intraocu-ar lens implantation and uncontrolled glaucoma withntraocular pressure (IOP) >18 mm Hg and <40 mm Hgn maximum tolerated medical therapy. INTERVENTIONS:50 mm2 Baerveldt glaucoma implant or trabeculectomyith mitomycin C (MMC). MAIN OUTCOME MEASURES: IOP,isual acuity, and reoperation for glaucoma.RESULTS: A total of 212 eyes of 212 patients were

nrolled, including 107 in the tube group and 105 in therabeculectomy group. At one year, IOP (mean � SD)as 12.4 � 3.9 mm Hg in the tube group and 12.7 �.8 mm Hg in the trabeculectomy group (P � .73). Theumber of glaucoma medications (mean � SD) was.3 � 1.3 in the tube group and 0.5 � 0.9 in therabeculectomy group (P < .001). The cumulative prob-bility of failure during the first year of follow-up was.9% in the tube group and 13.5% in the trabeculectomyroup (P � .017).CONCLUSIONS: Nonvalved tube shunt surgery wasore likely to maintain IOP control and avoid persistentypotony or reoperation for glaucoma than trabeculec-omy with MMC during the first year of follow-up in theVT Study. Both surgical procedures produced similar

OP reduction at one year, but there was less need forupplemental medical therapy following trabeculectomy

Supplemental Material available at AJO.com.See accompanying Article on page 23 and Editorial on page 141.ccepted for publication Jul 25, 2006.From the Bascom Palmer Eye Institute, Miller School of Medicine,niversity of Miami, Miami, Florida (S.J.G., J.C.S., W.J.F., D.L.B.);epartment of Ophthalmology, Duke University, Durham, North Caro-

ina (L.W.H.); and Department of Ophthalmology, University of Cali-ornia, Davis, Sacramento, California (J.D.B.).

sInquiries to Steven J. Gedde, MD, Bascom Palmer Eye Institute, 900.W. 17th Street, Miami, FL 33136; e-mail: [email protected]

© 2007 BY ELSEVIER INC. A002-9394/07/$32.00oi:10.1016/j.ajo.2006.07.020

ith MMC. (Am J Ophthalmol 2007;143:9–22. ©007 by Elsevier Inc. All rights reserved.)

LAUCOMA SURGERY IS PERFORMED WHEN FUR-

ther intraocular pressure (IOP) reduction is neededdespite the use of maximum tolerated medical

herapy and appropriate laser treatment. Trabeculectomyor guarded filtration procedure) is generally used as thenitial incisional glaucoma procedure.1,2 However, eyes inhich trabeculectomy has failed are at greater risk of

ailure with subsequent filtering surgery.3–9 Wound healingodulation with antifibrotic agents, such as mitomycin(MMC) and 5-fluorouracil (5-FU), improves the success

ate of trabeculectomy in eyes that have undergone previ-us ocular surgery,7–9 but the risk of complications is alsoncreased.7–9 The prevalence of bleb leaks, bleb-relatednfections, and bleb dysesthesia associated with a perilim-al filtering bleb has contributed to the growing use of tubehunts (or glaucoma drainage implants) as an alternativeo trabeculectomy.1,2

Practice patterns vary in the surgical management oflaucoma in eyes with previous ocular surgery.1,2 In 1996,hen and associates conducted an anonymous survey ofembers of the American Glaucoma Society and Japaneselaucoma Society to evaluate use of antifibrotic agents

nd tube shunts.1 The survey presented 10 clinical situa-ions requiring glaucoma surgical intervention. The major-ty of respondents (59% to 83%) preferred trabeculectomyith MMC for the clinical scenarios involving prior ocular

urgery, although many of those surveyed elected to use aube shunt, trabeculectomy with 5-FU, or trabeculectomyithout an antifibrotic agent. In 2002, Joshi and associates

eadministered the same survey to members of the Amer-can Glaucoma Society.2 Respondents still favored trab-culectomy with MMC for most clinical situations, but theercentage usage of tube shunts had significantly increased.he greatest practice pattern shift was observed in patientsith previous cataract and glaucoma surgery. In particular,

election of tube shunts as the preferred surgical approach

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ncreased from 7% to 22% in eyes with prior trabeculec-omy, and increased from 8% to 22% in eyes with priorxtracapsular or intracapsular cataract extraction.

The lack of consensus among glaucoma surgeons regard-ng the use of tube shunts or trabeculectomy with anntifibrotic agent in eyes that have had prior cataract orlaucoma surgery is not surprising, because similar surgicalesults have been reported with both glaucoma procedureshen studied separately. Success rates have ranged from0% to 88% for tube shunts10–18 and 48% to 86% forltering surgery with an antifibrotic agent7–9,19–23 in apha-ic/pseudophakic eyes. Success rates have ranged from4% to 88% for tube shunts10,12,14,15,17,18 and 61% to 100%or 5-FU and MMC trabeculectomy7–9,19–22,24–27 in eyesith failed filters. Comparable rates of severe complica-

ions have also been reported with tube shunt surgery andrabeculectomy with an adjunctive antifibrotic agent.28

The Tube Versus Trabeculectomy (TVT) Study wasesigned to prospectively compare the safety and efficacyf nonvalved tube shunt surgery and trabeculectomy withMC. Patients with uncontrolled glaucoma who had prior

ataract extraction with intraocular lens implantation orailed filtering surgery were enrolled in this multicenterlinical trial and randomized to placement of a 350 mm2

aerveldt glaucoma implant (Advanced Medical Optics,rvine, California, USA) or trabeculectomy with MMC0.4 mg/ml for four minutes). The goal of this investigatornitiated trial is to provide information that will assist inurgical decision-making in similar patient groups.

METHODS

HE INSTITUTIONAL REVIEW BOARD AT EACH CLINICAL

enter approved the study protocol before recruitment wastarted, and each patient gave informed consent. The studyas registered at www.clinicaltrials.gov. The design andethods of the TVT Study were previously described in

etail,29 and they are summarized as follows.

ELIGIBILITY CRITERIA: Inclusion criteria included ageetween 18 and 85 years, inadequately controlled glau-oma on maximum tolerated medical therapy with IOPetween 18 mm Hg and 40 mm Hg, and previous trabecu-ectomy and/or cataract extraction with intraocular lensmplantation. Exclusion criteria included no light percep-ion vision, pregnant or nursing women, active iris neo-ascularization or proliferative retinopathy, iridocornealndothelial syndrome, epithelial or fibrous downgrowth,phakia, vitreous in the anterior chamber for which aitrectomy was anticipated, chronic or recurrent uveitis,evere posterior blepharitis, unwillingness to discontinueontact lens use after surgery, previous cyclodestructiverocedure, prior scleral buckling procedure, presence ofilicone oil, conjunctival scarring precluding a trabeculec-
omy superiorly, and need for glaucoma surgery combined f
AMERICAN JOURNAL OF0

ith other ocular procedures or anticipated need fordditional ocular surgery. Only one eye of eligible patientsas included in the study.

RANDOMIZATION AND TREATMENT: The TVT Studyas conducted at 17 Clinical Senters. Eligibility was

ndependently confirmed at the Statistical Coordinatingenter. Patients enrolled in the study were randomized tolacement of a 350 mm2 Baerveldt glaucoma implant orrabeculectomy with MMC. Randomization was performedsing a permuted block design stratified by clinical centernd type of previous intraocular surgery. Neither theatient nor the clinician was masked to the randomizationssignment during follow-up.

A 350 mm2 Baerveldt glaucoma implant was placed inhe superotemporal quadrant in all patients randomized tohe tube group. A limbus-based or fornix-based conjunc-ival flap was dissected, and the implant was sutured toclera 10 mm posterior to the limbus. The Baerveldt tubeas completely occluded to temporarily restrict flow

hrough the device until encapsulation of the plate oc-urred. The surgeon was given the option of fenestratinghe tube for early IOP reduction. The Baerveldt tube wasnserted into the anterior chamber through a 23-gaugeeedle track. A patch graft was used to cover the limbalortion of the tube, and the conjunctiva was closed.All patients randomized to the trabeculectomy group

nderwent a trabeculectomy with mitomycin C superiorly.limbus-based or fornix-based flap was created, and a

uid-retaining sponge soaked in MMC (0.4 mg/ml) waspplied to the superior sclera for four minutes. A partial-hickness scleral flap was dissected, and a paracentesis wasade. A block of limbal tissue was excised underneath the

rabeculectomy flap. The scleral flap was reapproximatedo the scleral bed with interrupted or releasable 10-0 nylonutures. The conjunctiva was closed, and Seidel testing waserformed at the conclusion of the case.

PATIENT VISITS: Follow-up visits were scheduled oneay, one week, one month, three months, six months, oneear, 18 months, two years, three years, four years, and fiveears postoperatively. Each examination included mea-urement of Snellen visual acuity (VA), IOP, slit-lampiomicroscopy, Seidel testing, and ophthalmoscopy. Hum-hrey perimetry, Early Treatment Diabetic Retinopathytudy (ETDRS) VA, and quality of life using the Nationalye Institute-Visual Function Questionnaire (NEI VFQ-5) were assessed at the annual follow-up visits. A formalotility evaluation was performed in all patients at base-

ine and at the one-year and five-year follow-up visits, andt any visit after three months in which the patienteported diplopia. The examining clinician provided aeason for loss of 2 or more lines of Snellen VA at
ollow-up visits after three months.
OPHTHALMOLOGY JANUARY 2007

http://www.clinicaltrials.gov

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OUTCOME MEASURES: IOP and the rate of surgicalomplications were major outcome measures in the TVTtudy. Another outcome measure was failure, which wasrospectively defined as IOP �21 mm Hg or not reducedy 20% below baseline on two consecutive follow-up visitsfter three months, IOP �5 mm Hg on two consecutiveollow-up visits after three months, reoperation for glau-oma, or loss of light perception vision. Reoperation forlaucoma was defined as additional glaucoma surgery requir-ng a return to the operating room, such as placement of aube shunt. Cyclodestruction was also counted as a reop-ration for glaucoma. Interventions performed at thelit-lamp, such as needling procedures and laser suture lysis,ere not considered glaucoma reoperations. Eyes that hadot failed and were not on supplemental medical therapyere considered complete successes. Eyes that had not

ailed but required supplemental medical therapy wereefined as qualified successes. Other outcome measuresssessed in the TVT Study included VA, visual field, anduality of life.

STATISTICAL ANALYSIS: A sample size of 190 patients95 patients per treatment group) was selected to detect aifference in mean IOP of 2.5 mm Hg and a 5% differencen complication rates with a two-sided significance level of.05 and power of 0.80. This sample size yields 95% confi-ence limits of 2% to 11% around a complication rate of 5%.dditional patients were recruited to allow for losses to

ollow-up, and enrollment was terminated with 212 patients.Univariate comparisons between treatment groups were

erformed using the two-sided Student t test for continu-us variables and the Chi-square test or Fisher exact testor categorical variables. Snellen VA measurements wereonverted to logMAR equivalents for the purpose of datanalysis, as reported previously.9 The time to failure wasefined either as the time from surgical treatment to reop-ration for glaucoma, or as the time from surgical treat-ent to the first of two consecutive follow-up visits after

hree months in which the patient had persistent hypotonyIOP �5 mm Hg) or inadequately controlled IOP (IOP21 mm Hg or not reduced by 20%). Risk factors for

reatment failure were assessed for statistical significanceith the Kaplan-Meier survival analysis log-rank test. Mul-

ivariate analysis was performed using Cox proportionalazard regression analysis with forward stepwise elimina-ion. A P value of .05 or less was considered statisticallyignificant.

An independent Safety and Data Monitoring Commit-ee (SDMC) met twice per year to monitor the conduct ofhe study. A primary responsibility of the SDMC was toeview the differences in failure rates and the occurrence ofdverse events between treatment groups and to haltandomization early if treatment benefit or risk was so greator one treatment group that continuation of patientecruitment was deemed unethical. During the course of
he TVT Study, a significantly higher rate of reoperation c
TUBE VS TRABECULEOL. 143, NO. 1

or glaucoma was observed in the trabeculectomy groupompared with the tube group. The O’Brien-Flemingtopping rule was used to correct P values for the multipleooks that the SDMC was taking.30 Consideration wasiven to terminating enrollment early, but the SDMCetermined that continued recruitment did not representxcessive risk to patient safety.

RESULTS

RECRUITMENT AND RETENTION: A total of 212 pa-ients were enrolled in the TVT Study between October999 and April 2004. Randomization assigned 107 patientso placement of a 350 mm2 Baerveldt glaucoma implantnd 105 patients to trabeculectomy with MMC. Allatients received their assigned treatment.The progress of patients in the study is shown in Figure 1.

n the overall study group, four patients died within one yearf enrollment. There were 19 other patients who missed thene-year follow-up visit, but 10 of these patients returned forubsequent follow-up visits. Excluding deaths, 96.7% ofollow-up visits were completed during the first year of thetudy. The visit completion rate did not differ by treatmentroup (P � .26, Student t test). The number of patientsompleting each follow-up visit are shown in Figure 2.

BASELINE CHARACTERISTICS: The baseline character-stics of study patients are shown in Table 1. No significantifferences in demographic or clinical features were foundetween treatment groups at baseline. Additional detailsn randomized patients were provided in a previousublication.29

IOP REDUCTION: The baseline and follow-up IOPs forhe tube group and the trabeculectomy group are reportedn Table 2 and Figure 2. Patients who underwent addi-ional glaucoma surgery were censored from analysis afterhe time of reoperation. Both surgical procedures produced

significant reduction in IOP. In the tube group, IOPmean � SD) decreased from 25.1 � 5.3 mm Hg ataseline to 12.4 � 3.9 mm Hg at the one year follow-upisit (P � .001, paired t test). In the trabeculectomy group,OP (mean � SD) was reduced from 25.6 � 5.3 mm Hg ataseline to 12.7 � 5.8 mm Hg at the one-year follow-upisit (P � .001, paired t test). There was no significantifference in mean IOP between treatment groups at oneear (P � .73, Student t test). However, the trabeculec-omy group had significantly lower mean IOPs than theube group at all follow-up visits during the first threeostoperative months. At one year, the trabeculectomyroup had greater variability in IOP than the tube groupP � .030, Levene test for equality of variances).

An additional intent-to-treat analysis was performed,hich included patients who were reoperated for glau-
oma. At one year, IOP (mean � SD) was 12.4 � 3.9 mm
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g in the tube group and 12.9 � 6.0 mm Hg in therabeculectomy group. There was no significant differencen mean IOP between treatment groups taking into ac-ount all medical and surgical management during the firstear of follow-up (P � .55, Student t test).

MEDICAL THERAPY: Table 2 shows the number oflaucoma medications in the tube group and the trabecu-ectomy group at baseline and follow-up. Patients who

IGURE 1. Flowchart of patient progress in the Tube Versusrabeculectomy (TVT) Study.

IGURE 2. Distribution of intraocular pressure (IOP) ataseline and follow-up in the Tube Versus TrabeculectomyTVT) Study. Data are presented as mean � standard error ofhe mean. The number of participants completing each fol-ow-up visit are shown at the Bottom. Note that follow-up times not on a linear scale.

nderwent additional glaucoma surgery were censored s


rom analysis after the time of reoperation. There was aignificant reduction in the need for medical therapy inoth treatment groups. The number of glaucoma medica-ions (mean � SD) in the tube group decreased from 3.2 �.1 at baseline to 1.3 � 1.3 at the one-year follow-up visitP � .001, paired t test). The number of glaucoma medica-ions (mean � SD) in the trabeculectomy group waseduced from 3.0 � 1.2 at baseline to 0.5 � 0.9 at the oneear follow-up visit (P � .001, paired t test). There was aignificantly greater need for supplemental medical therapyn the tube group compared with the trabeculectomy groupt all follow-up visits (P � .001, Student t test). The meanumber of medications remained 1.3 � 1.3 in the tuberoup and 0.5 � 0.9 in the trabeculectomy group at oneear in an intent-to-treat analysis, which included patientsho underwent additional glaucoma surgery.

TREATMENT OUTCOMES: Table 3 reviews the out-omes of randomized patients, unadjusted for follow-upime. All patients who were seen at the one year follow-upisit or failed during the first year of the study werencluded in this analysis. There was a significantly higherailure rate in the trabeculectomy group than the tuberoup during the first year of follow-up. At one year,reatment failure had occurred in four (4%) patients in theube group and 13 (13%) patients in the trabeculectomyroup (P � .035, Chi-square test). In the tube group, 3534%) patients were classified as complete successes and 6563%) patients were qualified successes. In the trabeculec-omy group, 63 (63%) patients were complete successesnd 24 (24%) patients were qualified successes. Whereashe tube group had a higher overall success rate after oneear of follow-up, the trabeculectomy group had moreomplete successes (P � .001, Chi-square test).

Kaplan-Meier survival analysis was also used to compareailure rates between the two treatment groups (Figure 3).he cumulative probability of failure was 3.9% in the tuberoup and 13.5% in the trabeculectomy group at one yearP � .017, log rank test). The reasons for treatment failurere listed in Table 4. The most common cause for failure inoth treatment groups was inadequate IOP control. Thereere four patients in the tube group who had inadequatelyontrolled IOP, including one patient who required aeoperation for glaucoma. Failure because of inadequateOP control occurred in 10 patients in the trabeculectomyroup, including five patients who had additional glau-oma surgery. Among the patient group that failed becausef inadequate IOP control, the number of medicationsmean � SD) at the time of failure was 2.00 � 0.8 in theube group and 2.4 � 1.3 in the trabeculectomy groupP � .60, Student t test). Persistent hypotony was theause for treatment failure in three patients in the trab-culectomy group, and no patients in the tube group failedecause of hypotony. There were no eyes in either treat-ent group that lost light perception vision. There was no

ignificant difference in the distribution of reasons for


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ailure between treatment groups (P � .46, Fisher exactest).

Treatment outcomes were examined in patients withrevious trabeculectomy with MMC (stratum 4). The cumu-ative probability of failure at one year using Kaplan-Meierurvival analysis was 5.3% in the tube group and 13.3% inhe trabeculectomy group. The failure rates in this stratumere almost identical to those in the overall study group

TABLE 1. Baseline Characteristics of T

T

Age (years), mean � SD 70

Gender, n (%)

Male

Female

Race, n (%)

White

Black

Hispanic

Other

Diabetes mellitus, n (%)

Hypertension, n (%)

IOP (mm Hg), mean � SD 25

Glaucoma medications, mean � SD 3

Diagnosis, n (%)

POAG

CACG

PXFG

PG

Other

Lens status, n (%)

Phakic

PCIOL

ACIOL

Previous intraocular surgery

Mean � SD 1

Range

Interval (months), mean � SD� 5

ETDRS VA, mean � SD 62

Snellen VA

Median

Range 20

LogMAR mean � SD 0.4

ACIOL � anterior chamber intraocular lens; C

Early Treatment Diabetic Retinopathy Study; I

PCIOL � posterior chamber intraocular lens; PG �

glaucoma; PSD � pattern standard deviation; P

deviation; VA � visual acuity.

*Student t test.†Chi-square test.‡Exact permutation Chi-square test.§Mann-Whitney U test.�Interval between last intraocular surgery and

P � .65, test of stratum-treatment interaction). l


Table 5 and Figure 4 present the failure rates for thewo treatment groups using alternative outcome criteria.atients with persistent hypotony or reoperation for glau-oma were still classified as treatment failures; however,he upper IOP limit defining success and failure washanged. When inadequate IOP control was defined asOP greater than 17 mm Hg or not reduced by 20% on twoonsecutive follow-up visits after three months, the cumu-

ersus Trabeculectomy Study Patients

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Trabeculectomy Group

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11.0 71.1 � 9.9 .89*

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0) 48 (46)

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7) 42 (40)

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9) 36 (34) .49†

7) 63 (60) .76†

5.3 25.6 � 5.3 .56*

1.1 3.0 � 1.2 .17*

.057‡

2) 84 (80)

) 11 (10)

) 1 (1)

) 0 (0)

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2) 21 (20)

5) 80 (76)

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24.1 64.4 � 19.6 .56*

0 20/40 .76§

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� chronic angle-closure glaucoma; ETDRS �

intraocular pressure; MD � mean deviation;

entary glaucoma; POAG � primary open-angle

� pseudoexfoliation glaucoma; SD � standard

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ative probability of failure at one year was 4.9% in the

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ube group and 16.7% in the trabeculectomy group (P �008, log rank test). When inadequate IOP control wasefined as IOP greater than 14 mm Hg or not reduced by0% on two consecutive follow-up visits after threeonths, the cumulative probability of failure was 11.9% in

he tube group and 27.4% in the trabeculectomy group atne year (P � .008, log rank test). A significantly higherailure rate was observed in the trabeculectomy groupompared with the tube group using a broad range of IOPriteria to define success and failure.

Baseline demographic and clinical features were evalu-

TABLE 2. Intraocular Pressure and Medical Therapy atBaseline and Follow-up in the Tube Versus

Trabeculectomy Study

Tube Group

Trabeculectomy

Group P value*

Baseline

IOP (mm Hg) 25.1 � 5.3 25.6 � 5.3 .56

Glaucoma medications 3.2 � 1.1 3.0 � 1.2 .17

1 day

IOP (mm Hg) 21.3 � 11.8 16.8 � 10.4 .004

1 week

IOP (mm Hg) 19.0 � 9.8 14.0 � 8.5 �.001

Glaucoma medications 1.2 � 1.4 0.2 � 0.7 �.001

1 month

IOP (mm Hg) 18.5 � 9.8 12.6 � 7.3 �.001


3 months

IOP (mm Hg) 16.2 � 6.4 13.7 � 6.6 �.006


6 months

IOP (mm Hg) 13.5 � 4.2 12.8 � 5.9 .32


1 year

IOP (mm Hg) 12.4 � 3.9 12.7 � 5.8 .73


IOP � intraocular pressure.

Data are presented as mean � standard deviation.

*Student t test.

TABLE 3. Treatment Outcomes in the Tube VersusTrabeculectomy Study

Tube Group

(n � 104)


(n � 100) P value*

Failure 4 (4) 13 (13) .035

Success 100 (96) 87 (87) .035

Qualified 65 (63) 24 (24) �.001

Complete 35 (34) 63 (63) �.001

Data are presented as number (percentage).

*Chi-square test.

ted as possible predictors for treatment failure and are r


hown in Table 6. Only treatment was significantly asso-iated with outcome in univariate analysis (P � .017, logank test). Stratum, age, gender, race, diabetes mellitus,ypertension, lens status, number of previous intraocularurgeries, time since last intraocular surgery, preoperativeumber of medications, preoperative IOP, preoperativenellen VA, and Clinical Centers were not associatedith treatment failure either univariately or in a multivar-

ate model adjusted for treatment. However, glaucoma typeended toward significance as a predictor of treatment out-ome in univariate (P � .072, log rank test) and multi-ariate (P � .082, Cox regression, adjusted for treatment)nalyses. When adjusted for glaucoma type, treatment re-ained statistically significant (P � .013, Cox regression).

REOPERATION FOR GLAUCOMA: There was a tendencyor patients in the trabeculectomy group to require more

IGURE 3. Kaplan-Meier plots of the probability of failure inhe Tube Versus Trabeculectomy (TVT) Study.

TABLE 4. Reasons for Treatment Failure in the TubeVersus Trabeculectomy Study

Tube Group

(n � 4)


(n � 13)

Inadequate IOP control* 4 (100)‡ 10 (77)§

Persistent hypotony† 0 (0) 3 (23)

Loss of light perception 0 (0) 0 (0)


Data are presented as number (percentage).

P � .46 for the difference in distribution of reasons for failure

between treatment groups (Fisher exact test).

*IOP �21 mm Hg or not reduced by 20% below baseline on

two consecutive follow-up visits after 3 months or additional

glaucoma surgery.†IOP �5 mm Hg on two consecutive follow-up visits after

3 months.‡1 patient underwent additional glaucoma surgery.§5 patients underwent additional glaucoma surgery.

eoperations for glaucoma than the tube group, but this


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ifference did not reach statistical significance. A total ofve (5%) patients in the trabeculectomy group had reop-rations for glaucoma, which involved placement of aaerveldt glaucoma implant in all patients. In the tuberoup, one (1%) patient underwent a cyclophotocoagula-ion for inadequately controlled IOP. The difference ineoperation rate between treatment groups was almosttatistically significant (P � .086, log rank test).

Because the surgeon was not masked to the treatmentssignment, a potential bias existed in the decision toeoperate for IOP control. To evaluate for selection bias,he IOP levels were compared between treatment groupsmong patients who failed because of inadequate IOPontrol. The IOP (mean � SD) was 24 mm Hg in the oneatient in the tube group and 25.1 � 3.4 mm Hg in the fiveatients in the trabeculectomy group at the time ofeoperation for glaucoma (P � .78, Student t test). TheOP levels were also compared between the three patientsn the tube group and five patients in the trabeculectomyroup who failed because of inadequate IOP control, butid not undergo reoperation for glaucoma. In this patientroup, the IOP (mean � SD) at the time of failure was9.8 � 2.5 mm Hg in the tube group and 21.0 � 2.9 mm

TABLE 5. Cumulative Failure Rates in tAlternative O

IOP �21 mm Hg or not reduced by 20% below




*Patients with persistent hypotony or reoperati

IOP control criteria must be present on two con

failure.†Log–rank test from Kaplan-Meier analysis.

IGURE 4. Kaplan-Meier plots of the cumulative probability ofnadequate IOP control as IOP >17 mm Hg (Left) or IOP >1

g in the trabeculectomy group (P � .59, Student t test). V


he mean IOP before reoperation for glaucoma was similarn the tube group and trabeculectomy group, and there waso significant difference between treatment groups inean IOP among patients who failed because of inade-

uate IOP control but did not undergo additional glau-oma surgery. These observations suggest that there was noelection bias for reoperation for glaucoma.

VISUAL ACUITY: Visual acuity results are shown inable 7. There was a significant decrease in Snellen VAnd ETDRS VA in both treatment groups during the firstear of follow-up. In the tube group, logMAR Snellen VAmean � SD) decreased from 0.42 � 0.54 at baseline to.61 � 0.75 at the one-year follow-up visit (P � .001,aired t test), and ETDRS VA (mean � SD) was reducedrom 63 � 24 at baseline to 56 � 27 at one year (P � .001,aired t test). In the trabeculectomy group, logMARnellen VA (mean � SD) decreased from 0.37 � 0.38 ataseline to 0.49 � 0.56 at the one-year follow-up visitP � .003, paired t test), and ETDRS VA (mean � SD)eclined from 64 � 20 at baseline to 61 � 23 at one yearP � .008, paired t test). There was no significant differ-nce in Snellen VA (P � .20, Student t test) or ETDRS

be Versus Trabeculectomy Study withme Criteria*

Tube Group

(n � 107)


(n � 105) P value†

line 3.9% 13.5% .017

line 4.9% 16.7% .008

line 11.9% 27.4% .008

glaucoma are classified as failures. Inadequate

ive follow-up visits after 3 months to quality as

re in the Tube Versus Trabeculectomy (TVT) Study definingm Hg (Right).

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CTOMY STUDY 15

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TABLE 6. Risk Factor Analysis for Failure in the Tube Versus Trabeculectomy Study

Risk Factor Number (%) Cumulative Probability of Failure at 1 Year (%)*

P value

Univariate Multivariate

Stratum� .51� .55‡

1 94 (44) 11.6

2 49 (23) 6.7

3 35 (17) 3.2

4 34 (16) 8.8

Age (years) .26† .26‡

�60 years 31 (15) 14.4

60–69 59 (28) 12.1

70–79 79 (37) 6.9

�80 43 (20) 2.4

Gender .89† .94‡

Male 100 (47) 9.0

Female 112 (53) 8.3

Race .49† .54‡

White 95 (45) 7.8

Black 82 (39) 11.8

Hispanic 30 (14) 3.7

Other 5 (2) 0

Diabetes mellitus .70† .83‡

Yes 67 (32) 9.8

No 145 (68) 8.1

Hypertension .68† .58‡

Yes 124 (59) 7.9

No 88 (42) 9.6

Lens status .78† .84‡

Phakic 45 (21) 9.5

PCIOL 160 (76) 8.1

ACIOL 7 (3) 14.3

Previous intraocular surgery .89† .89‡

1 163 (77) 8.7

2 41 (19) 7.5

3 or 4 8 (4) 12.5

Time since last intraocular surgery (months) .51† .60‡

�6 months 15 (7) 13.3

�6 months 190 (93) 8.5

Glaucoma type .072† .082‡

Primary 190 (90) 7.4

Secondary 22 (10) 18.2

Preoperative number of glaucoma medications .97† .92‡

0–1 21 (10) 9.5

2–3 108 (51) 8.2

4–6 83 (39) 8.8

Preoperative IOP (mm Hg) .31† .29‡

�23 77 (36) 12.2

23–26 66 (31) 4.8

�26 69 (33) 8.1

Preoperative Snellen VA .93† .96‡

�20/30 106 (50) 8.8

20/40–20/150 74 (35) 9.0

�20/200 32 (15) 6.9

Continued on next page

AMERICAN JOURNAL OF OPHTHALMOLOGY6 JANUARY 2007

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he trabeculectomy group at one year, and the changesn Snellen VA (P � .34, Student t test) and ETDRS VAP � .44, Student t test) from baseline were also notignificantly different between treatment groups. Thereere 49 patients who did not have ETDRS VA at oneear, including 23 patients who missed the one-yearollow-up visit and 26 patients who failed to have ETDRSA measured. There were 23 patients who did not havenellen VA at one year because they missed the one-year

ollow-up visit.Snellen VA was decreased by 2 or more lines from

aseline in 31 (32%) patients in the tube group and 30

TABLE 6

Risk Factor Number (%)

Clinical centers

Enrolled �50% patients 133 (63)

Enrolled �50% patients 79 (37)

Treatment

Tube 107 (50)

Trabeculectomy 105 (50)

ACIOL � anterior chamber intraocular lens; IOP � intraocular press

*Kaplan-Meier survival analysis.†Log–rank test.‡Cox proportional hazard regression analysis, p value adjusted fo§Cox proportional hazard regression analysis, p value adjusted fo�Stratum 1 � previous cataract extraction; stratum 2 � previous

stratum 3 � previous trabeculectomy with 5-fluorouracil or combin

trabeculectomy with mitomycin C.

TABLE 7. Visual Acuity Results in t

Tube

ETDRS VA, mean � SD

Baseline 63

1 year 56

Snellen VA, logMAR mean � SD

Baseline 0.42

1 year 0.61

Loss of �2 Snellen lines, n (%)* 31

Glaucoma

Macular disease

Cataract

Other 1

Unknown

ETDRS � Early Treatment Diabetic Retinop

acuity.

*Patients may have more than one reason for†Student t test.‡Chi-square test.

33%) patients in the trabeculectomy group at one year, u


nd this difference in rate of vision loss betweenreatment groups was not statistically significant (P �.00, Chi-square test). The examining clinician wassked to provide a reason for reduction of two or moreines of Snellen VA from baseline. The most frequentauses of vision loss during the first year of the study wereataract in four patients in the tube group and nineatients in the trabeculectomy group, glaucoma in fouratients in the tube group and seven patients in therabeculectomy group, and macular disease in three pa-ients in the tube group and four patients in the trabecu-ectomy group. The reason for decreased vision was

ntinued

mulative Probability of Failure at 1 Year (%)*

P value

Univariate Multivariate

.37† .26‡

7.3

10.8

.017† .013§

3.9

13.5

CIOL � posterior chamber intraocular lens; VA � visual acuity.

tment.

ucoma type.

eculectomy or combined procedure without an antifibrotic agent;

ocedure with 5-fluorouracil or mitomycin C; stratum 4 � previous

ube Versus Trabeculectomy Study

p Trabeculectomy Group P value

64 � 20 .56†

61 � 23 .20†

4 .37 � .38 .40†

5 .49 � .56 .20†

30 (33) 1.00‡

7

4

9

6

8

tudy; SD � standard deviation; VA � visual

eased vision.

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CTOMY STUDY 17

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atients in the trabeculectomy group. Other miscellaneousauses for reduced vision in 14 patients in the tube groupncluded vitreous hemorrhage, corneal edema, superficialunctate keratitis, endophthalmitis, suprachoroidal hem-rrhage, and posterior capsular opacification. Other causesf vision loss in six patients in the trabeculectomy groupncluded corneal edema, superficial punctate keratitis,ndophthalmitis, suprachoroidal hemorrhage, and hypot-ny maculopathy.

DISCUSSION

HE TVT STUDY ENROLLED PATIENTS WITH MEDICALLY

ncontrolled glaucoma who had undergone previous cat-ract extraction with intraocular lens implantation and/orailed filtering surgery and randomized them to surgicalreatment with trabeculectomy with MMC or placementf a Baerveldt glaucoma implant. Both surgical proceduresere effective in lowering IOP. Among patients whoompleted one-year follow-up visits, trabeculectomy withMC produced a 49.5% reduction in IOP and placement

f a Baerveldt glaucoma implant achieved a 49.9% de-rease in IOP. These results are comparable with previoustudies of similar patients that reported IOP reductionanging from 38.6% to 61.4% for trabeculectomy withn adjunctive antifibrotic agent 21–23,25–27 and from 46.4%o 58.3% for tube shunt surgery.11,17 Many glaucomaurgeons have the impression that low IOP levels cannote achieved with tube shunts, but this is not supported byur results, which found a mean IOP of 12.4 mm Hg in theube group at one year.

There was no significant difference in mean IOP be-ween treatment groups after three months of follow-up.owever, the trabeculectomy group had lower IOPs than

he tube group at all time points during the first threeonths postoperatively. Although trabeculectomy pro-

uces an immediate reduction in IOP, nonvalved tubehunts such as the Baerveldt glaucoma implant require aemporary restriction of aqueous flow until fibrous encap-ulation of the plate occurs. As a result, nonvalved implantsre not open and functioning until several weeks postop-ratively. Surgeons in the TVT Study were given theption of fenestrating the tube at the time of surgicalmplantation, a technique that has been shown to providearly pressure reduction with nonvalved tube shunt sur-ery.31,32 Tube fenestration and medical therapy wereffective in providing moderate IOP reduction in the tuberoup in the early postoperative period. A majority ofatients in the tube group had the implant open betweenhe one-month and three-month follow-up visits, as indi-ated by the development of a bleb overlying the implantlate and reduction in IOP.Patients in the tube group were more likely to achieve

OP control and avoid persistent hypotony or reoperation
or glaucoma than the trabeculectomy group during the b

rst year of follow-up in the TVT Study. At one year, theumulative probability of failure was 3.9% in the tuberoup and 13.5% in the trabeculectomy group. The lowailure rate in the tube group compared with previoustudies of tube shunts10–18 may relate to refinements inurgical technique, as well as differences in length ofollow-up and study populations. The TVT Study excludedeveral secondary glaucomas with poor surgical prognosese.g., neovascular glaucoma and iridocorneal endothelialyndrome), and these glaucoma types were included inther case series of tube shunts. Inadequate IOP controlas the most common reason for failure in both treatmentroups. Although the overall failure rate was higher in therabeculectomy group than the tube group, the reasons forailure were distributed similarly between treatment groups.

Treatment success was subdivided into complete andualified successes, based on the need for supplementaledical therapy. Although the overall success rate wasigher for the tube group, the trabeculectomy group hadore complete successes. This is consistent with the

bserved greater need for glaucoma medications by theube group compared with the trabeculectomy group at allollow-up visits during the first year of the study. Tubehunts appear to require more supplemental medical ther-py than trabeculectomy with MMC to achieve a desiredevel of pressure reduction.

Despite a higher failure rate in the trabeculectomyroup, the mean IOP was similar between the two treat-ent groups and the mean number of glaucoma medica-

ions was actually lower in the trabeculectomy group. Thiss explained by a greater variability in IOP in the trabecu-ectomy group compared with the tube group. There wereore patients in the trabeculectomy group with extremes

f high and low IOP resulting in classification as failuresecause of inadequate IOP control and persistent hypot-ny. The few patients who failed because of hypotony hadhe effect of reducing the mean IOP and number of glau-oma medications in the trabeculectomy group. Evenhough the patients who failed because of inadequate IOPontrol were on more medical therapy, they representednly a small percentage of the total treatment group thatas used to calculate mean IOP and number of glaucomaedications. Among the patients who failed because of

nadequate IOP control, the mean number of glaucomaedications at the time of failure was similar between

reatment groups. This observation suggests that the higherailure rate in the trabeculectomy group was not related tonadequate treatment with medical therapy.

The ideal measure of success for any glaucoma therapy,hether medical or surgical, is the prevention of furtherlaucomatous optic nerve damage and visual field loss withreservation of visual function. We recognize that treat-ent success for individual patients cannot be defined by

n arbitrary IOP level, because individuals vary in theirusceptibility to the damaging effect of IOP. Nevertheless,
ecause IOP reduction is the goal of current glaucoma

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herapy, IOP is a reflection of the efficacy of medical orurgical treatment. The outcome criteria for the TVTtudy were developed prospectively, and our definitions ofuccess and failure are similar to previous studies involvinghe surgical treatment of glaucoma thereby facilitatingomparison with published results.7–27,33–43

The results of several recent multicenter randomizedlinical trials have suggested that IOP of 21 mm Hg or lessay be inadequate to prevent glaucomatous progression inany patients.44–46 To determine if the TVT Study results

hanged when more stringent IOP criteria were applied toefine success, Kaplan-Meier survival analyses were per-ormed using alternative outcome criteria. A higher failureate in the trabeculectomy group compared with the tuberoup was still observed when the upper IOP level defininguccess was reduced from 21 mm Hg to 17 mm Hg and4 mm Hg. Because the differences in treatment outcomesere present using a broad range of IOP success criteria,

he study results seem applicable to patients with early ordvanced glaucomatous damage.

Several baseline factors were examined as possible riskactors for treatment failure, and only treatment assign-ent predicted treatment outcome in both univariate andultivariate analyses. Patients with secondary glaucomas

ended to have a higher risk of failure compared withrimary glaucomas. Other studies have found that second-ry glaucomas have a higher rate of surgical failure withltering surgery6 and tube shunt surgery,36 although thesetudies included types of secondary glaucoma that werexcluded from the TVT Study (e.g., neovascular glaucomand uveitic glaucoma). It is possible that different factorsay be associated with failure of trabeculectomy and tube

hunt surgery. Furthermore, factors that predispose toailure because of inadequate IOP control are likely to beifferent from factors that cause failure because of persis-ent hypotony. There was an inadequate number of treat-ent failures at one year to evaluate for differences in risk

actors for failure between treatment groups and among thearious failure criteria.There was a trend toward a higher rate of reoperation for

laucoma in the trabeculectomy group compared with theube group after one year. Patients who fail trabeculectomynd require additional glaucoma surgery will generallyndergo repeat trabeculectomy or placement of a tubehunt.1,2 However, additional glaucoma surgery in eyeshat have failed tube shunt surgery is more complex andsually involves placement of a second tube shunt oryclodestruction.33,34 Investigators in the TVT Study wereot masked to the treatment assignment, and there was aotential for bias in the decision to reoperate for glaucoma.e explored for the possibility that surgeons may have had

higher threshold to perform additional glaucoma surgeryn the tube group than the trabeculectomy group. Thereas no significant difference between treatment groups inean IOP at the time of failure among patients who

nderwent reoperation for glaucoma or patients who failed u


ecause of inadequate IOP control but did not undergodditional glaucoma surgery. These observations suggesthat there was no selection bias for additional glaucomaurgery.

Visual acuity decreased in both treatment groupsuring the first year of follow-up. Snellen and ETDRS VAere similar between treatment groups at one year, and

here was no significant difference in the rate and reasonsor vision loss in the tube and trabeculectomy groups.ision loss of 2 or more Snellen lines was most frequently

ttributed to cataract by the examining clinicians, evenhough only 45 (21%) patients enrolled in the TVT Studyere phakic. There is strong evidence that glaucoma

urgery increases cataract incidence and progression.47

andomized clinical trials have shown a higher incidencef cataract formation in patients treated with trabeculec-omy compared with those managed with medical or laserherapy.44,48–50 Case series have also reported cataract toe the leading case of vision loss after trabeculectomy.51,52

Wilson and associates compared the Ahmed glaucomaalve implant (New World Medical, Inc, Rancho Cu-amonga, California, USA) to trabeculectomy in a ran-omized clinical trial involving 117 patients.37 Lowerean IOP was observed in the trabeculectomy group, and

he Ahmed group had a greater adjunctive medicationequirement. The cumulative probability of success (IOP21 mm Hg and at least 15% reduction in IOP from

reoperative level) was similar between the two treatmentroups. This study was performed in Saudi Arabia and Srianka, and it included patients with all glaucoma typesnd some eyes that had undergone previous ocular surgery.

follow-up study continued enrollment in Sri Lanka to aotal of 123 patients with primary open-angle glaucomand angle-closure glaucoma without previous ocular sur-ery.38 Lower mean IOP was noted in the trabeculectomyroup than the Ahmed group during the first year. How-ver, the IOPs were similar between treatment groups withonger follow-up, and there was no difference in theumulative probability of success.

Wilson’s studies reported lower mean IOP in the trab-culectomy group compared with the Ahmed group afterne year of follow-up, but similar success rates were notedetween treatment groups.37,38 Conversely, the TVT Studyound similar mean IOP between the tube and trabeculec-omy groups at one year, but a higher success rate wasbserved in the tube group. The difference in study resultsetween the TVT Study and the studies by Wilson mayelate to differences in study populations, success andailure criteria, and the type of tube shunts used. The TVTtudy also enrolled a larger number of patients and hadetter follow-up during the first year than Wilson’s studies,nd this increases the power of the study to detectifferences between treatment groups.There are several limitations to the TVT Study. The

tudy population was restricted to patients who had
ndergone previous cataract extraction with intraocular
CTOMY STUDY 19

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ens implantation, trabeculectomy, or both. Severalecondary glaucomas (i.e., neovascular glaucoma, uve-tic glaucoma, and glaucoma associated with the irido-orneal endothelial syndrome and epithelial or fibrousowngrowth) were excluded, as well as conditions thatould increase the risk of infection should the patient beandomized to the trabeculectomy group (i.e., contactens wear and severe posterior blepharitis). The resultsf the TVT Study cannot be directly applied to theseatient groups that were not included in the study.imilarly, eyes were excluded if other ocular proceduresere needed in conjunction with glaucoma surgery, or if

here was an anticipated need for additional ocularurgery in the future. This study does not address thessue of whether trabeculectomy with an antifibroticgent or tube shunt surgery is preferable if concurrent orubsequent ocular surgery is planned. All patients ran-omized to the tube group underwent placement of a50 mm2 Baerveldt glaucoma implant. Although severaletrospective studies have failed to detect a difference inurgical results when comparing different implantypes,39 – 43 the results of the present study cannot beeneralized to other glaucoma drainage implants. Aubgroup of patients enrolled in the TVT Study (i.e.,hose with a history of prior trabeculectomy with MMC)ad already failed one treatment arm of the study, andotentially could have introduced bias in favor of theube group. We felt that the study question of whetherne surgical procedure was superior to the other waslinically relevant in eyes that had failed a MMCrabeculectomy, and a separate stratum (stratum 4) wasreated for these eyes to facilitate data analysis andddress concerns about possible bias. Stratum was not aignificant predictor of treatment failure in risk factornalysis, and patients with prior trabeculectomy withMC had similar treatment outcomes as the overall

atient group.The results of the TVT Study suggest that consider-

tion should be given to expanding the role of tubehunts in the surgical management of glaucoma. Tradi-ionally, these devices have been reserved for refractorylaucoma in individuals at high risk for failure withtandard filtering surgery.53 In eyes with previous cata-act or glaucoma surgery, the TVT Study found thatonvalved tube shunt surgery and trabeculectomy withMC produced similar IOP reduction at one year.

atients treated with trabeculectomy with MMC re-uired less supplemental medical therapy, but thoseith tube shunts were more likely to maintain IOPontrol and avoid persistent hypotony or reoperation forlaucoma during the first year of follow-up. Vision lossccurred at a similar rate after both surgical procedures.he TVT Study does not demonstrate clear superiorityf one glaucoma operation over the other. There arether factors that must be considered when selecting a
urgical procedure in patients with medically uncon-

rolled glaucoma, including the surgeon’s skill andxperience with both operations and the patient’s med-cation tolerance, availability, and compliance withherapy. The benefit of each procedure in reducing IOPust also be interpreted in view of its adverse events.ur companion paper describes the surgical complica-

ions encountered in the TVT Study during the firstear of follow-up.

HIS STUDY WAS SUPPORTED BY RESEARCH GRANTS FROMfizer, Inc, New York, New York, Advanced Medical Optics, Irvine,alifornia, the National Eye Institute (Grant No. EY014801), National

nstitutes of Health, Bethesda, Maryland, and Research to Preventlindness, Inc, New York, New York. The authors indicate financialonflict of interest (see complete list of investigators at AJO.com.). Allhe authors and list of investigators were involved in design and conductf the study, involved in collection, management, analysis, and interpre-ation of the data and involved in preparation, review, or approval of theanuscript.

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2. Smith MF, Doyle JW, Sherwood MB. Comparison of theBaerveldt glaucoma implant with the double-plate Mol-teno drainage implant. Arch Ophthalmol 1995;113:444 –447.

3. Ayyala RS, Zurakowski D, Monshizadeh R, et al. Compari-son of double-plate Molteno and Ahmed glaucoma valve inpatients with advanced uncontrolled glaucoma. OphthalmicSurg Lasers 2002;33:94–101.

4. Lichter PR, Musch DC, Gillespie BW, et al. Interim clinicaloutcomes in the Collaborative Initial Glaucoma TreatmentStudy comparing initial treatment randomized to medica-tions or surgery. Ophthalmology 2001;108:1943–1953.

5. The AGIS Investigators. The Advanced Glaucoma Inter-vention Study (AGIS): 7. The relationship between controlof intraocular pressure and visual field deterioration. Am JOphthalmol 2000;130:429–440.

6. Heijl A, Leske MC, Bengtsson B, et al. Reduction ofintraocular pressure and glaucoma progression: results fromthe Early Manifest Glaucoma Trial. Arch Ophthalmol 2002;120:1268–1279.

7. Hylton C, Congdon N, Friedman D, et al. Cataract after glaucomafiltration surgery. Am J Ophthalmol 2003;135:231–232.

8. Collaborative Normal-Tension Glaucoma Study Group. Com-parison of glaucomatous progression between untreated pa-tients with normal-tension glaucoma and patients withtherapeutically reduced intraocular pressures. Am J Ophthal-
mol 1998;126:487–497.
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5

5

5

5

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9. The AGIS Investigators. The Advanced Glaucoma Inter-vention Study (AGIS): 6. Effect of cataract on visual fieldand visual acuity. Arch Ophthalmol 2000;118:1639 –1652.

0. The AGIS Investigators. The Advanced Glaucoma Inter-vention Study (AGIS): 8. Risk of cataract formation after


1. Costa VP, Smith M, Spaeth GL, et al. Loss of visual acuityafter trabeculectomy. Ophthalmology 1993;100:599–612.

2. Cheung JC, Wright MM, Murali S, Pederson JE. Intermedi-ate-term outcome of variable dose mitomycin C filteringsurgery. Ophthalmology 1997;104:143–149.

3. Assaad MH, Baerveldt G, Rockwood EJ. Glaucoma drainage
trabeculectomy. Arch Ophthalmol 2001;119:1771–1779. devices: pros and cons. Curr Opin Ophthalmol 1999;10:147–153.
REPORTING VISUAL ACUITIES

he AJO encourages authors to report the visual acuity in the manuscript using the same nomenclature that was used inathering the data provided they were recorded in one of the methods listed here. This table of equivalent visual acuitiess provided to the readers as an aid to interpret visual acuity findings in familiar units.

Table of Equivalent Visual Acuity Measurements

Snellen Visual Acuities

Decimal Fraction LogMAR4 Meters 6 Meters 20 Feet

4/40 6/60 20/200 0.10 �1.0

4/32 6/48 20/160 0.125 �0.9

4/25 6/38 20/125 0.16 �0.8

4/20 6/30 20/100 0.20 �0.7

4/16 6/24 20/80 0.25 �0.6

4/12.6 6/20 20/63 0.32 �0.5

4/10 6/15 20/50 0.40 �0.4

4/8 6/12 20/40 0.50 �0.3

4/6.3 6/10 20/32 0.63 �0.2

4/5 6/7.5 20/25 0.80 �0.1

4/4 6/6 20/20 1.00 0.0

4/3.2 6/5 20/16 1.25 �0.1

4/2.5 6/3.75 20/12.5 1.60 �0.3

4/2 6/3 20/10 2.00 �0.3

From Ferris FL III, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. Am J Ophthalmol 1982;94:91–96.


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LIST OF INVESTIGATORS

PARTICIPATING CENTERS AND COMMITTEES IN THE

UBE VERSUS TRABECULECTOMY STUDY

LINICAL CENTERS:

Bascom Palmer Eye Institute, Miller School of Medi-ine, University of Miami (Miami, Florida): Principalnvestigator: Steven Gedde, M.D.; Coinvestigators: Doug-as Anderson, M.D., Donald Budenz, M.D., M.P.H., Made-ine Del Calvo, Francisco Fantes, M.D., David Greenfield,

.D., Elizabeth Hodapp, M.D., Richard Lee, M.D., Ph.D.,lexia Marcellino, Paul Palmberg, M.D. Ph.D., Richardarrish II, M.D.Duke University (Durham, North Carolina): Princi-

al Investigator: Leon Herndon, M.D.; Coinvestigators:ratap Challa, M.D., Cecile Santiago-Turla, M.D.Indiana University (Indianapolis, Indiana): Principal

nvestigator: Darrell WuDunn, M.D., Ph.D.Loyola University (Maywood, Illinois): Principal In-

estigator: Geoffrey Emerick, M.D.Medical College of Wisconsin (Milwaukee, Wiscon-

in): Principal Investigator: Dale Heuer, M.D.Medical University of South Carolina (Charleston,

outh Carolina): Principal Investigator: Alexander Kent,.D.; Coinvestigators: Carol Bradham, Lisa Langdale.Moorfields Eye Hospital (London, England): Principal

nvestigator: Keith Barton, M.D.; Coinvestigator:rancesca Amalfitano, Poornima Rai, M.D.New York Eye and Ear Infirmary (New York, New

ork): Principal Investigator: Paul Sidoti, M.D.; Coinves-igators: Amy Gedal, James Luayon, Roma Ovase, Katy Tai

Scripps Clinic (La Jolla, California): Principal Investi-ator: Quang Nguyen, M.D.; Coinvestigator: Neva Miller

St. Louis University (St. Louis, Missouri): Principalnvestigator: Steven Shields, M.D.; Coinvestigators: Kevinnderson, Frank Moya, M.D.University of California Davis (Sacramento, Califor-

ia): Principal Investigator: James Brandt, M.D.; Coinves-igator: Michele Lim, M.D., Marilyn Sponzo.

University of Florida (Gainesville, Florida): Principal Inves-igator: Mark Sherwood, M.D.; Coinvestigator: Revonda Burke

University of Oklahoma (Oklahoma City, Oklahoma):rincipal Investigator: Gregory Skuta, M.D.; Coinvestiga-ors: Jason Jobson, Lisa Ogilbee, Adam Reynolds, M.D.

University of Southern California (Los Angeles, Califor-ia): Principal Investigator: Rohit Varma, M.D., M.P.H.; Coin-estigators: Brian Francis, M.D., Frances WalonkerUniversity of Texas Houston (Houston, Texas): Prin-

ipal Investigator: Robert Feldman, M.D.; Coinvestigators:aura Baker, Nicholas Bell, JoLene Carranza, AthenaspinozaUniversity of Virginia (Charlottesville, Virginia):

rincipal Investigator: Bruce Prum, M.D.; Coinvestigator:
anis Beall D

University of Wisconsin (Madison, Wisconsin): Prin-ipal Investigator: Todd Perkins, M.D.; Coinvestigators:aul Kaufman, M.D., Tracy Perkins, Barbara Soderling.Statistical Coordinating Center, Bascom Palmer Eye

nstitute, Miller School of Medicine, University of Mi-mi (Miami, Florida): William Feuer, M.S., Luz Londono,oyce Schiffman, M.S.

Safety and Data Monitoring Committee: Philip Chen,.D., William Feuer, M.S., Joyce Schiffman, M.S., Kuldev

ingh, M.D., M.P.H., George Spaeth, M.D., Martharight, M.D.Steering Committee: Keith Barton, M.D., James

randt, M.D., Geoffrey Emerick, M.D., Robert Feldman,.D., Steven Gedde, M.D., Leon Herndon, M.D., Daleeuer, M.D., Alexander Kent, M.D., Quang Nguyen,.D., Richard Parrish II, M.D., Todd Perkins, M.D., Bruce

rum, M.D., Mark Sherwood, M.D., Steven Shields, M.D.,aul Sidoti, M.D., Gregory Skuta, M.D., Rohit Varma,.D., M.P.H., Darrell WuDunn, M.D., Ph.D.Study Chairmen: Steven Gedde, M.D., Dale Heuer.D., Richard Parrish II, M.D.

FINANCIAL DISCLOSURES

The following investigators have disclosed a financialnterest in the previous and current manufacturer of theaerveldt glaucoma implant.Keith Barton, M.D.: Pfizer, honoraria. James Brandt, M.D.:

fizer, consultant, speakers bureau, honoraria; Advancededical Optics, consultant. Donald Budenz, M.D., M.P.H.:

fizer, honoraria, speakers bureau. Philip Chen, M.D.: Pfizer,onoraria. Geoffrey Emerick, M.D.: Pfizer, honoraria, speak-rs bureau. Francisco Fantes, M.D.: Pfizer, speakers bureau.obert Feldman, M.D.: Pfizer, consultant, grant support,onoraria, speakers bureau. Brian Francis, M.D.: Pfizer, speak-rs bureau. Steven Gedde, M.D.: Pfizer, honoraria, speakersureau; Advanced Medical Optics, honoraria. David Green-eld, M.D.: Pfizer, consultant, honoraria, speakers bureau.eon Herndon, M.D.: Pfizer, honoraria, speakers bureau. Daleeuer, M.D.: Pfizer, honoraria, speakers bureau. Paul Kauf-an, M.D.: Pfizer, consultant, grant support, honoraria,

peakers bureau, travel expenses; Advanced Medical Optics,onsultant, grant support. Richard Lee, M.D., Ph.D.: Pfizer,peakers bureau. Frank Moya, M.D.: Pfizer, speakers bureau.uang Nguyen, M.D.: Pfizer, consultant, honoraria, speakers

ureau. Paul Palmberg, M.D., Ph.D.: Pfizer, consultant, speak-rs bureau, honoraria. Richard Parrish II, M.D.: Pfizer, con-ultant, honoraria. Bruce Prum, M.D.: Pfizer, grant support,peakers bureau. Adam Reynolds, M.D.: Pfizer, honoraria.teven Shields, M.D.: Pfizer, consultant. Kuldev Singh, M.D.,.P.H.: Pfizer, consultant. Gregory Skuta, M.D.: Pfizer, con-

ultant, honoraria, speakers bureau. George Spaeth, M.D.:fizer, grant support, honoraria. Rohit Varma, M.D., M.P.H.:fizer, consultant, grant support, honoraria, speakers bureau.artha Wright, M.D.: Pfizer, speakers bureau. Darrell Wu-
unn, M.D., Ph.D.: Pfizer, honoraria, speakers bureau.
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Biosketch

teven J. Gedde, MD, is an Associate Professor of Ophthalmology and Residency Program Director at the Bascom Palmerye Institute, Miami, Florida. He is a study chairman in the Tube Versus Trabeculectomy Study (TVT). Dr Geddeesearch interests include glaucoma drainage implants, complications of glaucoma surgery, quality of life, and residentducation.

AMERICAN JOURNAL OF OPHTHALMOLOGY2.e2 JANUARY 2007

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