Nasolacrimal duct obstruction (NLDO) is a common ocular condition in the first year of life. Many cases will resolve spontaneously or with massage. Many studies of primary treatment of NLDO have been reported. These case series have largely been retrospective, uncontrolled, and conducted in single centers.
In children with NLDO symptoms, Peterson and Robb found that 58 of 65 (89%) blocked ducts spontaneously resolved by 13 months of age. Peterson and Robb did not report the age distribution for the cohort, but they do note that 67% percent of the spontaneous resolutions occurred before 6 months of age. Nelson and colleagues reported that among 113 infants enrolled into a study between 1 month and 10 months of age (median age = 5 months), 107 (95%) had NLDO spontaneously resolved by 13 months of age. Ghuman and colleagues found spontaneous resolution in 128 (32%) of 402 eyes treated with massage and antibiotics by 13 months, however the ages at which the children had initiated medical management were not specified. Paul reported that among 55 children with infantile NLDO who were first examined at 3 months of age or younger, 51 of 55 (91%) had ducts that were open at 12 months.6 With regard to spontaneous resolution in children who still have NLDO symptoms by a certain age, the Paul report showed that among 37 eyes with NLDO symptoms at 6 months, 26 (70%) were clear without surgical intervention by 12 months of age and that among 23 eyes with NLDO symptoms at 9 months, 12 (52%) had cleared by 12 months. The substantial uncertainty regarding an estimate of spontaneous resolution is a primary reason for conducting the current study.
Probing is the most widely-used initial treatment for NLDO in infancy. Our group recently completed a prospective observational study which found a 78% (95% CI = 74% to 82%) success proportion of probing among children aged 6 to <12 months. This overall success proportion was similar to that reported by others, better than the 69% reported by Katowitz and Welsh, though worse than the 92% reported by Robb.
Two differing approaches to nasolacrimal probing have been most often been used: (1) immediate office probing (early probing – generally soon after 6 months of age) and (2) medical management (episodic antibiotic drops with massage of the lacrimal sac) until 9-13 months of age followed by probing under general anesthesia or conscious sedation (deferred probing). The advantages of early probing are the avoidance of general anesthesia or conscious sedation, immediate resolution of symptoms, fewer physician visits, fewer antibiotic prescriptions, lesser cost per procedure, and possible prevention of fibrosis from inflammation in the nasolacrimal duct. The advantages of deferred probing include more subject comfort with the procedure and possible avoidance of a surgical procedure completely.
Both early and deferred probing approaches are usually successful for treatment of NLDO. Early probing done in the office setting with restraint and only topical anesthesia was successful in 92% of children in a retrospective review of a series of 2369 infants. These authors found a decline in success proportions with this office-based approach after 9 months of age. Success proportions of 77% to 97% have been reported in children younger than 18 months with conventional probing with anesthesia. In our previous prospective observational study of probing, 84% of the probings performed in an office setting were done under one year of age and 64% of the probings performed in a surgical facility were done at one year of age or older. The study found that the 239 eyes that underwent office probing procedures had a slightly lower proportion with success (72% [95% CI = 66% to 78%]) compared with the 661 eyes that underwent surgical facility probings (80% [95% CI = 77% to 84%]). Limiting the office probing cohort to the 132 eyes from 105 subjects aged 6 to <10 months old, the proportion with success was 75% (95% CI = 66% to 82%) (PEDIG, unpublished data). We speculated that the lower success with office probings might be due to a less robust procedure (e.g., probe passed only once) being performed in the office setting. However, because our study was not randomized and because the investigators who performed office probings did so nearly exclusively, we could not eliminate the possibility that subject selection bias and/or an investigator effect may be important factors underlying the observed difference in success between the office and facility settings.
The optimal approach to the management of NLDO in the first year of life remains uncertain. Our prospective observational data suggest a slightly reduced chance of success with immediate office probing;however, immediate office probing may be more cost-effective even if the proportion with success is lower. For a subject undergoing a single operation, immediate office probing is less expensive than deferred probing in a facility because there is no fee for anesthesia, the facility, or for medications prescribed during the pre-operative observation period. Some portion of this lower cost would be offset however by the additional cost of a second procedure if the initial office probing is not successful. Deferred facility probing is more expensive per procedure; however, the overall costs are reduced by the number of children whose NLDO spontaneously resolves while waiting to perform the procedure in a facility. This has been widely discussed by clinicians and has been studied using clinical decision analysis. Using a hypothetical spontaneous resolution rate of 70%, Kassoff found that deferred facility probing had a higher cost than immediate office probing. In a preliminary model developed with the assistance of Kevin Frick, PhD, we found that a hypothetical spontaneous resolution rate of about 75% equalizes the costs between immediate office probing and deferred facility probing and that a higher spontaneous resolution rate could cause the overall cost to shift in favor of deferred facility probing being less costly (personal communication, 1/17/2008).
