Balloon Catheter Dilation and Nasolacrimal Intubation for Treatment of Nasolacrimal Duct Obstruction Following a Failed Probing

Abstract

Objective

To compare the outcome of balloon catheter dilation and nasolacrimal intubation as treatments for congenital nasolacrimal duct obstruction (NLDO) after a failed probing in children less than 4 years of age

Methods

We conducted a prospective, non-randomized multicenter study which enrolled 159 children aged 6 to <48 months who had a history of a single failed nasolacrimal duct probing and had at least one of the following clinical signs of NLDO present: epiphora, mucous discharge and/or increased tear lake. One hundred ninety-nine eyes underwent either balloon catheter nasolacrimal duct dilation or nasolacrimal duct intubation. Treatment success was defined as no epiphora, mucous discharge or increased tear lake present at the outcome visit six months after surgery.

Results

Treatment success was reported in 65 of 84 eyes (77%, 95% CI = 65% to 85%) in the balloon group compared with 72 of 88 eyes (84%, 95% CI = 74% to 91%) eyes in the intubation group (risk ratio for success for intubation vs. balloon = 1.08, 95% CI = 0.95 to 1.22).

Conclusions

Balloon catheter dilation and nasolacrimal duct intubation each alleviate the clinical signs of persistent nasolacrimal duct obstruction in a similar proportion of patients.

INTRODUCTION

Congenital nasolacrimal duct obstruction (NLDO) is a common condition of infancy and early childhood. Most cases resolve spontaneously or following lacrimal sac massage.^1–4 For children whose blockage does not resolve spontaneously, probing of the nasolacrimal duct is generally a successful surgical treatment.^5–10 We found in a prospective observational study of 955 eyes treated with probing as an initial procedure in children 6 to 36 months of age that 78% of eyes were successfully treated.¹¹ For patients in whom initial probing is unsuccessful, a second procedure is usually recommended.

Surgical procedures for persistent NLDO after a failed probing include repeat probing, nasolacrimal duct intubation, and balloon catheter dilation. There is currently no preferred practice for the management of these children.^{12, 13} Several case series have reviewed the outcomes of repeat probing for persistent NLDO, with success ranging from 25% to 69%.^{9, 10, 14, 15} These varied results for a second probing led to the introduction of nasolacrimal intubation more than 50 years ago.¹⁶ More recently, balloon catheter dilation has been used for treatment of persistent NLDO.¹⁷ Goldstein and colleagues suggested that balloon catheter dilation or monocanalicular intubation are equally effective choices for a second surgery following failed probing based on their results in a non-randomized, retrospective case series.¹⁸

We initially designed and launched a prospective randomized study to compare balloon catheter dilation with nasolacrimal intubation for treatment of persistent NLDO after a failed probing. However, we were unable to recruit sufficient patients because parents were reluctant to accept randomization and most investigators preferred to perform their usual procedure. Thus we modified our protocol to conduct a prospective, non-randomized study with the choice of treatment determined by the clinician. Herein we report the results.

METHODS

This study, supported through a cooperative agreement with the National Eye Institute of the National Institutes of Health, was conducted by the Pediatric Eye Disease Investigator Group (PEDIG) at 39 clinical sites. Investigators were predominantly pediatric ophthalmologists, although a few oculoplastic sub-specialists also participated. The protocol and Health Insurance Portability and Accountability Act of 1996-compliant informed consent forms were approved by the respective institutional review boards. The parent or guardian of each study patient gave written informed consent. The complete protocol is available at http://public.pedig.jaeb.org. The major aspects are summarized below.

The study included children 6 to <48 months of age who were planning to undergo a balloon catheter dilation or a nasolacrimal intubation as a second surgical procedure for the treatment of NLDO within the next 30 days. Major eligibility criteria included onset of NLDO symptoms prior to 6 months chronological age; presence of at least one sign of NLDO (epiphora, increased tear lake, and/or mucopurulent discharge in the absence of an upper respiratory infection or ocular surface irritation); previous failed single primary probing procedure for nasolacrimal duct obstruction; no history of nasolacrimal intubation, balloon catheter dilation, more than one probing, or dacryocystorhinostomy; and absence of Down syndrome. In addition, children with craniosynostosis, Goldenhar sequence, clefting syndromes, hemifacial microsomia or any midline facial anomaly were excluded.

Enrollment and Surgery

At the enrollment visit, each of three clinical signs of NLDO (epiphora, mucous discharge and increased tear lake) was directly observed by the surgeon and reported as either present or absent. A Dye Disappearance Test (DDT) without topical anesthesia was performed by a certified examiner according to a protocol described in a previous report.¹¹

All procedures were performed under general anesthesia in a surgical facility (i.e., a hospital outpatient surgical department or ambulatory surgical center). Surgery was to occur within 30 days of enrollment. With the exception of the 8 patients who were enrolled and randomized prior to the change in our study design (3 balloon dilation, 2 intubation, and 3 balloon dilation in one eye and intubation in the other eye), the choice of nasolacrimal duct balloon catheter dilation or intubation was at investigator discretion.

Balloon catheter nasolacrimal duct dilation consisted of punctal dilation of at least one punctum, passage of a probe, followed by passage of a semi-flexible wire probe with an inflatable balloon on the tip (Lacri-CATH – Quest Medical, Inc., Allen, Texas 75002-4211) into the nasal cavity. The size of the probe used prior to passage of the balloon catheter was at investigator discretion. For the balloon catheter, the 2 mm diameter size was used for children less than 30 months of age, while the 3 mm diameter size was used for children 30 to <48 months of age, as recommended by the manufacturer. The inflation protocol specified by the manufacturer in their product labeling was followed (available at http://www.lacricath.com/procedure/). In brief, the balloon is inflated for 90 seconds, deflated, inflated for 60 seconds, withdrawn 5 mm, and the inflation/deflation protocol repeated.

Nasolacrimal duct intubation consisted of dilation of at least one punctum and the placement of a monocanalicular or bicanalicular tube. Probing prior to passage of the tube, the type and brand of tube used, and the method of securing the tube (if secured) were at investigator discretion. The protocol stipulated that the tube should remain in place for 2 to 5 months and then be removed by the surgeon while the child was awake or under conscious sedation.

Patency was confirmed by touching the probe or balloon catheter in the nasal cavity with a second probe, by visualization of the probe beneath the inferior turbinate, retrieval of the intubation tubing from the nose, or by recovery of fluorescein-colored saline from the nose after irrigation through the nasolacrimal system. Infracture of the inferior turbinate bone was optional. The nature of the obstruction was classified by the clinician as simple or complex, with simple defined as a single obstruction which was easily passed during the probing procedure and complex defined as a blockage or multiple blockages anywhere along the tear drainage pathway that causes more difficulty than usual with probe passage such as a blockage at the valve of Hasner, a tight inferior turbinate blocking flow, canalicular problems, or multiple obstructions in the NLD. The prescription of peri-operative and post-operative antibiotics and steroids were at investigator discretion.

Follow Up Examinations

The primary outcome visit occurred 6 months (±1 month) after surgery. Patients had an interim visit timed 1 month (±1 week) after balloon catheter dilations and 1 month (±1 week) after tube removal for nasolacrimal intubations. At both follow-up visits, a trained and certified examiner other than the operating surgeon directly observed the presence or absence of each of three clinical signs of NLDO (epiphora, increased tear lake, and mucous discharge), and a DDT was also performed.

If a child presented at the primary outcome visit with symptoms of an upper respiratory infection and one or more clinical signs of NLDO, the child returned 1 to 3 weeks later to repeat the outcome examination.

Statistical Analysis

The primary outcome was treatment success or failure six-months after surgery based on an assessment of clinical signs. Success was defined as the absence of all three clinical signs: epiphora, increased tear lake, and mucous discharge. Eyes that were re-operated prior to a given visit were considered treatment failures for that visit. The primary analysis was a comparison of the proportion of eyes with treatment success between treatment groups. A risk ratio and a 95% confidence interval (CI) was calculated using Poisson regression.¹⁹ For each treatment group, point estimates for the proportion of eyes with six-month treatment success and 95% CIs were calculated using logistic regression. Both types of regression models used generalized estimating equations to adjust for correlation between eyes of patients who had both eyes operated.²⁰ To be included in the primary analysis, the primary outcome examination could be performed no earlier than 3 months from surgery. Confounding was assessed by evaluating factors distributed differentially between treatment groups in separate regression models with the factor and treatment group as covariates and in an overall adjusted model which included all potential confounders. Results were also obtained from an alternative analysis (last-observation-carried-forward method) using data from the interim visit to replace missing primary outcome data. Additional analyses evaluated treatment success based on DDT results at the primary outcome visit.

Within the intubation group, we used Poisson regression to calculate risk ratios and 99% confidence intervals to evaluate whether treatment success was related to the length of time the tubes remained in place or to tube type (monocanalicular vs. bicanalicular). For the analysis of tube type, we excluded a single patient who had a different tube type in each eye as this patient also had discordant outcomes, a situation which presented difficulties with the adjustment for correlation between eyes of the same subject.

Patients who underwent bilateral surgery and who received balloon dilation in one eye and intubation in the other eye are included in both patient cohorts and for the eye-level analyses, only the eye that underwent the specified procedure was included in the analysis.

Analyses were conducted using SAS version 9.1 (SAS Institute Inc. Cary, NC).

RESULTS

Between March 2005 and July 2007, 95 eyes of 73 subjects underwent balloon catheter and 104 eyes of 90 subjects underwent nasolacrimal intubation for NLDO that was not cured by an initial probing. Four subjects with both eyes operated had each type of procedure in one eye. Thirty (60%) investigators performed nasolacrimal intubations exclusively, 14 (28%) performed balloon catheter dilations exclusively, and 6 (12%) performed both procedures.

Baseline Characteristics

The 159 patients ranged in age from 7.3 to 47.2 months with a mean age of 21.0±8.9 months. 81 (51%) patients were female, 125 (79%) were white, and 42 (26%) had bilateral disease. Six patients with bilateral disease underwent a different procedure in each eye—four underwent intubation and balloon dilation (three of whom were randomized to this assignment), and two underwent intubation and simple probing (the eye which received simple probing is excluded from the analysis). Baseline characteristics are shown by treatment group in the Table.

Table.

Baseline Characteristics of Study Cohort^a

	Surgery Type
	Balloon Catheter Dilation	Nasolacrimal Intubation
Patient-Level Characteristics	N = 73	N =90
Gender: Female, N %	39 (53)	45 (50)
Race/ethnicity, N %
White	57 (78)	72 (80)
African-American	4 (5)	6 (7)
Hispanic or Latino	7 (10)	4 (4)
Other	5 (7)	8 (9)
Age at onset in months, N %
Birth - <1	58 (79)	69 (77)
1 to <6	15 (21)	21 (23)
Age at primary probing, in months, N %
Mean (SD)	13.2 (4.5)	14.1 (7.7)
Range	4 to 25	1 to 44
6 to <12	30 (41)	39 (43)
12 to <24	42 (58)	42 (47)
24 to <36	1 (1)	5 (6)
36 to <48	0 (0)	3 (3)
Unknown	0 (0)	1 (1)
Age at second procedure, in months, N %
Mean (SD)	20.7 (7.8)	21.2 (9.8)
Range	7.3 to 40.8	7.4 to 47.2
6 to <12	5 (7)	13 (14)
12 to <24	48 (66)	50 (56)
24 to <36	15 (21)	17 (19)
36 to <48	5 (7)	10 (11)
Laterality, N %
Unilateral	47 (64)	70 (78)
Bilateralb	26 (36)	20 (22)
Location of surgery, N %
Ambulatory surgery center	50 (68)	31 (34)
Hospital	23 (32)	59 (66)
Classification of obstruction, N %
Simple	46 (63)	54 (60)
Complex	22 (30)	32 (36)
Simple/Complex	5 (7)	4 (4)
Inferior turbinate infracture, N %
Yes	17 (23)	31 (34)
No	56 (77)	59 (66)
Tube type, N %
Monocanalicular	-----	41 (46)
Bicanalicular	-----	48 (53)
Monocanalicular/Bicanalicularc	-----	1 (1)
Patency confirmed,d N %	72 (99)	79 (88)
Eye-Level Characteristics	N = 95	N = 104
Epiphora present, N %	69 (73)	87 (84)
Mucous discharge present, N %	54 (57)	60 (58)
Increased tear lake present, N %	93 (98)	102 (98)
Dye Disappearance Test, N %
Normal	3 (3)	1 (1)
Indeterminate	11 (12)	14 (13)
Abnormal	81 (85)	89 (86)

^aNote that 4 patients are in both the balloon procedures cohort and the intubation cohort as they had intubation in one eye and balloon in the other.

^bIn the balloon cohort, four bilateral patients had intubation performed in the other eye. In the intubation cohort, four patients had balloon performed in the other eye and two patients had simple probing performed in the other eye.

^cOne patient with bilateral disease had a monocanalicular tube in one eye and a bicanalicular tube in the other eye.

^dRefers to patency confirmed by any of the following methods: metal on metal; fluorescein irrigation and recovery from nose, or visualization. Failure to confirm patency could mean either 1) that patency was confirmed but by another method, or 2) that patency was not achieved, or 3) that no attempt had been made to confirm patency.

Complications

Complications were reported for a single patient in each treatment group. In the balloon catheter dilation group, a child with vomiting and possible aspiration during anesthesia induction was admitted for overnight observation but was released the next day without sequelae. In the intubation group there was a torn canaliculus which was surgically repaired.

Visit Completion

The primary outcome visit was completed by 59 (81%) patients in the balloon dilation group and by 75 (83%) patients in the intubation group. Primary outcome visits were completed 6.2±1.1 months from surgery (range = 3.0 to 9.5) in the balloon dilation group and 6.5±1.1 months (range = 5.0 to 9.4) in the intubation group. Of completed visits, the visit occurred within the 6 month ±1 month window in 45 (76%) and 56 (75%) patients in the balloon dilation and intubation groups, respectively. For patients who underwent intubation, the primary outcome visits were completed 3.7±2.0 months after tube removal (range = 0.6 to 7.5).

Study Outcomes

Treatment success, defined as the absence of clinical signs of NLDO and without re-operation prior to the 6-month visit, was reported in 65 of 84 eyes with outcome data (77%, 95% CI = 65% to 85%) in the balloon catheter group and in 72 of 88 eyes with outcome data (84%, 95% CI = 74% to 91%) eyes in the intubation group (risk ratio for success for intubation vs. balloon = 1.08, 95% CI = 0.95 to 1.22). All treatment failures were due to presence of clinical signs of NLDO at the primary outcome visit except for five cases in the balloon group in which patients were re-operated before the 6-month visit. An adjusted model including age, laterality, inferior turbinate infracture, hospital vs. ASC setting, and baseline epiphora yielded similar results (risk ratio for success for intubation vs. balloon = 0.99, 95% CI = 0.87 to 1.12). Results were also similar for an alternative analysis using data from the interim visit to impute for the missing the primary outcome data from 11 eyes (5 for balloon group, 6 for intubation group) (risk ratio for intubation vs. balloon = 1.11, 95% CI = 0.97 to 1.28).

In the balloon catheter and intubation groups respectively, the DDT was normal in 56 (71%) and 71 (83%), indeterminate in 11 (14%), and 7 (8%), and abnormal in 12 (15%) and 10 (9%). The risk ratio for normal dye disappearance was 1.23 (95% CI = 0.98 to 1.54) for intubation vs. balloon.

Association of Duration of Tube Retention and Tube Type with Treatment Success

Nasolacrimal duct tubes were removed a mean of 2.8±1.7 months after surgery (range = 0.0 to 7.0 months). These were removed less than 2 months after surgery in 28 (31%) patients, between 2 months and 5 months in 52 (58%), 5 months or later in 8 (9%), and after an unknown length of time in 2 (2%). The proportion of eyes with treatment success was 90% in the 59 eyes which had tubes left in for at least 2 months compared with 70% in the 29 eyes which had tubes left in for less than 2 months (risk ratio = 1.27, 99% CI = 0.91 to 1.79).

The proportion of eyes with treatment success was similar in the 40 eyes with monocanalicular intubation and in the 48 eyes with bicanalicular intubation (79% vs. 87%). The risk ratio for success with bicanalicular compared with monocanalicular tubes is 1.07 (99% CI = 0.82 to 1.39).

DISCUSSION

We conducted a prospective, non-randomized study of the surgical management of persistent NLDO after a probing in children 6 to <48 months old. Balloon catheter nasolacrimal duct dilation and nasolacrimal duct intubation were successful in a similar proportion of patients with persistent NLDO, 77% and 84% respectively.

There are a number of non-comparative series published for each of these procedures for persistent NLDO after a single probing. Balloon catheter dilation after failed probing has been reported in several retrospective case series to have success rates ranging from 53% to 95%.^21–24 Nasolacrimal duct intubation after failed probing has been reported in several retrospective cases series, mostly of bicanalicular intubation, to have success rates ranging from 66% to 100%.^25–36 For monocanalicular intubation with the Monoka tube (FCI, Issy Les-Molineaux Cedex, France) as a secondary treatment, the one available report showed a 67% success rate.³⁷ We are aware of one report in the literature¹⁸ of a retrospective non-randomized comparison of balloon catheter dilation and monocanalicular intubation after failed probing that found 86% (36 of 42) success with balloon catheter dilation and 91% (32 of 35) success with intubation. Among intubation procedures, we examined whether tube type and duration of tube retention were related to the likelihood of success. We did not find a difference between success rates in bicanalicular and monocanalicular intubation, a finding which is similar to our report on initial intubations for NLDO.³⁸ We found that tubes left in place for 2 months or longer (7 months maximum) appeared to have a higher success proportion than those with tubes left in for less than 2 months (90% vs. 70%); however, this finding was not statistically significant, likely due to our small sample size. Most reports on the optimum duration of tube retention are from retrospective studies of intubation performed most often as a second or third procedure. Some authors have found longer durations of retention improved the outcome,^{37, 39} whereas other have found no impact of duration of tube retention.^{38, 40}

Our study has a number of strengths. We utilized prospective data collection with investigator certification and outcome assessment at a uniform time interval. There were a large number of participating investigators, which may improve generalizability. However, there are several limitations as well. The most important is that our study was not randomized and thus there could have been selection bias with regard to choice of procedure (balloon catheter dilation or nasolacrimal duct intubation). However, since most investigators performed only one type of procedure, selection bias would be partially mitigated. This relationship between investigator and procedure type prevents any assessment for potential investigator effects. Another limitation is our small sample size. We were able to recruit only about a quarter of the sample size upon which RCT had been based (320 patients per treatment group). As a result, our power for the treatment group comparison is substantially reduced. An additional limitation is that loss to follow up was higher than optimal, at 15%.

Both intubation and balloon catheter dilation are performed in a surgical facility under general anesthesia. The tubes currently cost the facility between $60 and $100, whereas the balloon catheter costs the facility $306 for unilateral and $555 for bilateral dilations (LacriCath Catalog Price List, as of 8/2007). Nasolacrimal tubes may be removed in the office or in a facility with sedation. In the latter instance, that would add substantially to the cost of the procedure. However, in our study only 4% were removed in a facility, essentially negating this cost for the majority of patients.

In conclusion, balloon catheter dilation and nasolacrimal intubation were successful in a similar proportion of patients with persistent NLDO (77% and 84%, respectively). Both procedures should be considered suitable treatments for persistent NLDO following a single failed probing.

The Pediatric Eye Disease Investigator Group

Clinical Sites that Participated in this Protocol

Sites are listed in order by number of patients enrolled into the study. Personnel are listed as (I) for Investigator, (C) for Coordinator, and (E) for Examiner.

Erie PA - Pediatric Ophthalmology of Erie

Nicholas A. Sala, (I); Rhonda M. Hodde, (C); Veda L. Zeto, (C)

Cranberry TWP PA - Everett and Hurite Ophthalmic Association

Darren L. Hoover, (I); Pamela A. Huston, (C)

Saint Paul MN - Associated Eye Care

Susan Schloff, (I); Valori E. Host, (C)

Concord NH - Concord Eye Care P.C

Christie L. Morse, (I); Caroline C. Fang, (C)

Providence RI - Pediatric Ophthalmology and Strabismus Associates

David Robbins Tien, (I); Glenn E. Bulan, (I); Danielle M. Ledoux, (I); Heidi C. Christ, (C); Myra B. McGuinness, (C); Brenda G. Toro, (E)

Columbus OH - Pediatric Ophthalmology Associates, Inc

Don L. Bremer, (I); Cybil M. Cassady, (I); Richard P. Golden, (I); Mary Lou McGregor, (I); Gary L. Rogers, (I); Rae R. Fellows, (C)

Houston TX - Texas Children’s Hospital

Evelyn A. Paysse, (I); Kimberly G. Yen, (I); Maria Castanes, (C); Michele L. Parker, (C)

Minneapolis MN - University of Minnesota^*

C. Gail Summers, (I); Jill S. Anderson, (I); Erick D. Bothun, (I); Stephen P. Christiansen, (I); Andrew R. Harrison, (I); Ann M. Holleschau, (C); Kimberly S. Merrill, (E); Katherine M. Hogue, (E)

Englewood CO - Children’s Eye Physicians

Anna Steele, (I); Christopher M. Bardorf, (I); Justin T. Cohen, (I); Diana M. DeSantis, (I); Robert A. King, (I); Jamie Kilpatrick, (C); Shari A. Lufcy, (E); Andrea X Mosher, (E); Crystal X Vasquez, (E)

Atlanta GA - The Emory Eye Center

Scott R. Lambert, (I); Amy K. Hutchinson, (I); Rachel A. Robb, (C)

Lancaster PA - Family Eye Group

David I. Silbert, (I); Noelle S. Matta, (C)

Boise ID - Katherine Ann Lee, Intermountain Eye Centers

Katherine A. Lee, (I); Bonita R. Schweinler, (C)

West Des Moines IA - Wolfe Clinic

Donny W. Suh, (I); Marilee McNeece, (C); Rhonda J. Countryman, (E); Lisa Fergus, (E)

Chicago Ridge IL - The Eye Specialists Center, L.L.C

Benjamin H. Ticho, (I); Alexander J. Khammar, (I); Deborah A. Clausius, (C)

Oklahoma City OK - Dean A. McGee Eye Institute, University of Oklahoma

Lucas Trigler, (I); R. Michael Siatkowski, (I); Connie J. Dwiggins, (C); Kathy S. Weekley, (C)

South Charleston WV - Children’s Eye Care & Adult Strabismus Sugery

Deborah L. Klimek, (I); Crystal A. Sigmon, (C); Lisa L. Winter, (C)

Aberdeen NC - Family Eye Care of the Carolinas

Michael John Bartiss, (I); Tennille F. McGaw, (C)

Colorado Springs CO - The Children’s Eye Center

Dave H. Lee, (I); Nieca D. Caltrider, (I); Kelly A. Martinez, (C)

Durham NC - Duke University Eye Center

Laura B. Enyedi, (I); David K. Wallace, (I); Sarah K. Jones, (C)

Hershey PA - Penn State University

Joel Weinstein, (I); Michael J. Wilkinson, (I); Laura E. Walter, (C)

South Charleston WV - Mark D. Steinvurzel, M.D., PLLC

Mark D. Steinvurzel, (I)

Wichita KS - Grene Vision Group

Charles R. Whitfill, (I); David A. Johnson, (I); Ruth D. Dannar, (C)

Baltimore MD - Greater Baltimore Medical Center

Mary Louise Z. Collins, (I); Maureen A. Flanagan, (C)

Calgary - Alberta Children’s Hospital

William F. Astle, (I); Michael E. Ashenhurst, (I); Kenneth G. Romanchuk, (I); Ania M. Paszuk, (C); Heather J. Peddie, (C)

Dallas TX - UT Southwestern Med Ctr

David R. Weakley, (I); Clare L. Dias, (C)

Nashville TN - Vanderbilt Eye Center^*

Sean P. Donahue, (I); David G. Morrison, (I); Genise G. Mofield, (C); Sandy A. Owings, (C)

Philadelphia PA - Children’s Hospital of Philadelphia

Brian J. Forbes, (I); James A. Katowitz, (I); Monte D. Mills, (I); Graham E. Quinn, (I); Alexandra Huebner, (C); Tina Alvarado Taylor, (C); Melissa L. Ehnbom, (E); David R. Phillips, (E); Sonia Zhu, (E)

Rochester NY - University of Rochester Eye Institute

Matthew D. Gearinger, (I); Nancy M. Fedick, (C); Doreen M. Francis, (C)

Sacramento CA - The Permanente Medical Group

James B. Ruben, (I); Dipti Desai, (C)

Albuquerque NM – Children’s Eye Center of New Mexico

Todd A. Goldblum, (I); Angela Alfaro, (C); Rachel Baca, (C); Regan R. Foster, (E)

Ann Arbor MI - University of Michigan

Monte A. Del Monte, (I); Maya Eibschitz-Tsimhoni, (I); Jorie L. Jackson, (C)

Dallas TX - Pediatric Ophthalmology

David R. Stager, (I); Joost Felius, (C)

Grand Rapids MI - Pediatric Ophthalmology, P.C

Patrick J. Droste, (I); Robert J. Peters, (I); Jan Hilbrands, (C)

Madison WI - University of Wisconsin, Dept. of Ophthalmology & Visual Sciences

Yasmin S. Bradfield, (I); Erika D. Soderling, (C)

Mechanicsburg PA - Armesto Eye Association

David I. Silbert, (I); Noelle S. Matta, (C)

Portland OR - Casey Eye Institute^*

David T. Wheeler, (I); John Ng, (I); Ann U. Stout, (I); Kimberley A. Beaudet, (C); Claudia Nichols, (E); Paula Rauch, (E); Sharon Susanka,(E)

Sacramento CA - University of California, Davis Dept. of Ophthalmology

Mary O’Hara, (I); Maedi M. Bartolacci, (C)

Waterbury CT - Eye Care Group, PC

Andrew J. Levada, (I); Jonathan E. Silbert, (I); David N Comstock, (C); Cheryl Schleif, (C); Tabitha L. Walker, (C); Lakiesha M. Gentry, (E); Lisa A. Marcil, (E)

Wilmette IL - Pediatric Eye Associates

Deborah R. Fishman, (I); Lisa C. Verderber, (I); JoAnn Spieker, (C)

Nasolacrimal Duct Obstruction Treatment Study Steering Committee

Darron A. Bacal (2005), Danielle L. Chandler, Stephen P. Christiansen (2005), Eric R. Crouch III (2006–2007), Donald F. Everett, Jonathan M. Holmes, Katherine A. Lee (2006–2007), Noelle S. Matta (2005), Michael X. Repka, David I. Silbert, Susan Schloff (2006–2007), Bonita Schweinler (2007), D. Robbins Tien, David K. Wallace, Lori Zeto (2006)

PEDIG Coordinating Center - Tampa, FL

Roy W. Beck, Brian D. Becker, Nicole M. Boyle, Christina M. Cagnina-Morales, Debora A. Cagnina, Danielle L. Chandler, Laura E. Clark, Sharon R. Constantine, Katrina L. Dawson, Quayleen Donahue, Mitchell Dupre, Brooke P. Fimbel, Heidi A. Gillespie, Raymond T. Kraker, Stephanie V. Lee, Lee Anne Lester, Shelly T. Mares, B. Michele Melia, Pamela S. Moke, Jim L. Pyner, Nicole Reese, Diana E. Rojas, Sydney L. Shrader, Heidi J. Strayer

National Eye Institute - Bethesda, MD

Donald F. Everett

PEDIG Executive Committee

Roy W. Beck, Eileen E. Birch, Stephen P. Christiansen (2007– 2008), Susan A. Cotter, Sean P. Donahue (2005–2006), Donald F. Everett, Jonathan M. Holmes, Darren L. Hoover (2007–2008), Raymond T. Kraker (2005-Current), Michael X. Repka, Nicholas A. Sala (2006), Mitchell M. Scheiman (2007–2008), David K. Wallace (2006-current)

PEDIG Data and Safety Monitoring Committee

John D. Baker, William Barlow, Edward G. Buckley, Barry Davis, Velma Dobson, John L. Keltner, Hana Osman, Earl A. Palmer, Dale L. Phelps, Stephen W. Poff, Richard A. Saunders, Lawrence Tychsen, Marie Diener-West