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Cochrane Database of Systematic Reviews

Probing for congenital nasolacrimal duct obstruction

Overview of attention for article published in Cochrane database of systematic reviews, July 2017
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  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (88th percentile)
  • Above-average Attention Score compared to outputs of the same age and source (56th percentile)

Mentioned by

26 tweeters
1 Facebook page
1 Wikipedia page


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122 Mendeley
Probing for congenital nasolacrimal duct obstruction
Published in
Cochrane database of systematic reviews, July 2017
DOI 10.1002/14651858.cd011109.pub2
Pubmed ID

Carisa Petris, Don Liu


Congenital nasolacrimal duct obstruction (NLDO) is a common condition causing excessive tearing in the first year of life. Infants present with excessive tearing or mucoid discharge from the eyes due to blockage of the nasolacrimal duct system, which can result in maceration of the skin of the eyelids and local infections, such as conjunctivitis, that may require antibiotics. The incidence of nasolacrimal duct obstruction in early childhood ranges from 5% to 20% and often resolves without surgery. Treatment options for this condition are either conservative therapy, including observation (or deferred probing), massage of the lacrimal sac and antibiotics, or probing the nasolacrimal duct to open the membranous obstruction at the distal nasolacrimal duct. Probing may be performed without anesthesia in the office setting or under general anesthesia in the operating room. Probing may serve to resolve the symptoms by opening the membranous obstruction; however, it may not be successful if the obstruction is due to a bony protrusion of the inferior turbinate into the nasolacrimal duct or when the duct is edematous (swollen) due to infection such as dacryocystitis. Additionally, potential complications with probing include creation of a false passage and injury to the nasolacrimal duct, canaliculi and puncta, bleeding, laryngospasm, or aspiration. To assess the effects of probing for congenital nasolacrimal duct obstruction. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2016, Issue 8); MEDLINE Ovid (1946 to 30 August 2016); Embase.com (1947 to 30 August 2016); PubMed (1948 to 30 August 2016); LILACS (Latin American and Caribbean Health Sciences Literature Database; 1982 to 30 August 2016), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), last searched 14 August 2014; ClinicalTrials.gov (www.clinicaltrials.gov), searched 30 August 2016; and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), searched 30 August 2016. We did not use any date or language restrictions in the electronic searches for trials. We included randomized controlled trials (RCTs) that compared probing (office-based or hospital-based under general anesthesia) versus no (or deferred) probing or other interventions (observation alone, antibiotic drops only, or antibiotic drops plus massage of the nasolacrimal duct). We did not include studies that compared different probing techniques or probing compared with other surgical procedures. We included studies in children aged three weeks to four years who may have presented with tearing and conjunctivitis. Two review authors independently screened studies for inclusion and independently extracted data and assessed risk of bias for the included studies. We analyzed data using Review Manager software and evaluated the certainty of the evidence using GRADE. We identified two RCTs and no ongoing studies; one of the included RCTs was registered. The studies reported on 303 eyes of 242 participants who had unilateral or bilateral congenital nasolacrimal duct obstruction. For both included studies, the interventions compared were immediate office-based probing to remove the duct obstruction versus deferred probing, if needed, after 6 months of observation or once the child reached a certain age.The primary outcome of the review, treatment success at 6 months, was reported partially in one study. Treatment success was not reported at this time point for all children in the immediate probing group; however, 77 of 117 (66%) eyes randomized to deferred probing had resolved without surgery 6 months after randomization and 40 (34%) eyes did not resolve without probing. For children who had unilateral NLDO, those randomized to immediate probing had treatment success more often than those who were randomized to deferred probing (RR 1.41, 95% CI 1.12 to 1.78; 163 children; moderate-certainty evidence). Treatment success for all children was assessed in the study at age 18 months; as an ad hoc analysis in the included study, results were presented separately for children with unilateral and bilateral NLDO (RR 1.13, 95% CI 0.99 to 1.28 and RR 0.86, 95% CI 0.70 to 1.06, respectively; very low-certainty evidence).In the other small study (26 eyes of 22 children), more eyes that received immediate probing were cured within one month after surgery compared with eyes that were randomized to deferred probing and analyzed at age 15 months (RR 2.56, 95% CI 1.16 to 5.64). We considered the evidence to be low-certainty due to imprecision from the small study size and risk of bias concerns due to attrition bias.One study reported on the number of children that required reoperation; however, these data were reported only for immediate probing group. Nine percent of children with unilateral NLDO and 13% with bilateral NLDO required secondary procedures.One study reported cost-effectiveness of immediate probing versus deferred probing. The mean cost of treatment for immediate probing was less than for deferred probing; however, there is uncertainty as to whether there is a true cost difference (mean difference USD -139, 95% CI USD -377 to 94; moderate-certainty evidence).Reported complications of the treatment were not serious. One study reported that there were no complications for any surgery and no serious adverse events, while the other study reported that bleeding from the punctum occurred in 20% of all probings. The effects and costs of immediate versus deferred probing for NLDO are uncertain. Children who have unilateral NLDO may have better success from immediate office probing, though few children have participated in these trials, and investigators examined outcomes at disparate time points. Determining whether to perform the procedure and its optimal timing will require additional studies with greater power and larger, well-run clinical trials to help our understanding of the comparison.

Twitter Demographics

The data shown below were collected from the profiles of 26 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 122 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 122 100%

Demographic breakdown

Readers by professional status Count As %
Researcher 17 14%
Student > Master 15 12%
Student > Bachelor 12 10%
Student > Postgraduate 8 7%
Student > Doctoral Student 7 6%
Other 21 17%
Unknown 42 34%
Readers by discipline Count As %
Medicine and Dentistry 38 31%
Nursing and Health Professions 15 12%
Social Sciences 5 4%
Pharmacology, Toxicology and Pharmaceutical Science 5 4%
Computer Science 4 3%
Other 12 10%
Unknown 43 35%

Attention Score in Context

This research output has an Altmetric Attention Score of 18. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 21 December 2017.
All research outputs
of 16,289,364 outputs
Outputs from Cochrane database of systematic reviews
of 11,465 outputs
Outputs of similar age
of 267,916 outputs
Outputs of similar age from Cochrane database of systematic reviews
of 256 outputs
Altmetric has tracked 16,289,364 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 92nd percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 11,465 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 24.1. This one has gotten more attention than average, scoring higher than 72% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 267,916 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 88% of its contemporaries.
We're also able to compare this research output to 256 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 56% of its contemporaries.