Pediatrics and Strabismus

This paper details a retrospective review of Dr. Robb's records from 1971-1997 at the Children's Hospital of Boston. 329 patients were identified, 242 qualified for inclusion. Exclusion criteria included treatment prior to one year of age, canalicular obstruction, history of two failed probings, no obstruction present at time of probing, dacryocystocele, craniofacial abnormalities or tumor. Of those included, 51 patients had bilateral obstructions.

Diagnosis was made by history of epiphora beginning early in life with obstruction clinically confirmed on examination.

Technique: probing under minimal general anesthesia followed by irrigation. Follow up in one week. If no effect was noted, repeat probing was performed in most cases. Some underwent silicone intubation or a DCR, presumably because the author believed the nasolacrimal system had no bony osteum at the distal portion of the duct. The explanation of when to proceed with more advanced surgical options was not discussed.

Results from 23 probings (no mention of how many of these were bilateral) were unavailable, lost to follow up. For the 280 probings analyzed, the average cure rate was 96%.

280 Probings
	12-14 months	15-17 months	18-23 months	24-35 months	36+ months
Cured	88.9%	96.8%	90.7%	96.4%	92.6%
Improved	9.3%	0	5.6%	3.6%	0
Failed	1.8%	3.2%	3.7%	0	7.4%
Incomplete F/U	9.3%	4.8%	11.2%	7.2%	7.4%

Of the 8 failures, silicone tubes or DCR were performed and was curative in all.

Delaying nasolacrimal probing beyond one year of age does not lead to a lower success rate as previously described by Katowitz et al in AJO 1987. This evaluation should be performed on the records of multiple surgeons and the pooled results published. The controversy regarding early vs. late probing is not over yet although there is evidence that if no serious infections develop, waiting is a very reasonable option as late probing is effective. When, where and how to probe may be dependent on anatomic considerations, surgeon preferences, parental concerns or the frequency and serverity of infections.

Raymond Maguaran, M.D.
Boston, MA

Pediatrics and Strabismus

OBJECTIVE: Nasolacrimal duct intubation with Silastic tubes often is used for the treatment of congenital nasolacrimal duct obstruction. The more established intubation technique uses tubing designed for bicanalicular intubation. A commercial product now is available for monocanalicular intubation (Monoka tube, FCI, Issy-Les-Moulineaux Cedex, France), made possible by a punctal anchor attached to the proximal end of the tubing. The authors evaluated the complications and results of their experience with Silastic tube monocanalicular intubation for treatment of congenital nasolacrimal duct obstruction.

DESIGN: The study design was a retrospectively reviewed clinical trial with the results compared to a historic cohort treated with an alternative medical device.

PARTICIPANTS: Thirty-nine pediatric patients with 48 obstructed congenital nasolacrimal ducts were available for treatment and postoperative follow-up. The historic cohort included 25 cases of congenital nasolacrimal duct obstruction.

INTERVENTION: The participants were treated with monocanalicular Silastic tube intubation. The historic cohort was treated with bicanalicular Silastic tube intubation. The tubes were left in place for 4 to 6 months before planned removal.

MAIN OUTCOME MEASURES: Dye disappearance tests were performed before and after surgery after removal of the tube. Intraoperative and postoperative complications were noted.

RESULTS: Significant complications of the monocanalicular tubing included 1 case of bilateral preseptal cellulitis, 1 case of migration of the punctal anchor into the canaliculus that required surgical correction, 2 cases of a corneal abrasion, 1 case of a corneal ulcer, and 21 cases of premature removal of the tube. Of the 21 cases with premature tube removal, 13 (62%) of the eyes showed an improvement in the symptoms and results of dye disappearance test. Of the 27 cases that completed the full course of tube placement, all the tubes were removed successfully in an office setting, and 25 (93%) showed an improvement in the symptoms and results of dye disappearance test. Significant complications of the authors' bicanalicular intubation include stretching of the punctum, tube dislodgement, and tube removal requiring general anesthesia to the patient. Of the authors' 25 cases treated with bicanalicular intubation, 17 (68%) showed an improvement in the symptoms and results of dye disappearance test.

CONCLUSION: The recently introduced Silastic monocanalicular tubing offers an alternative to bicanalicular tubing for treatment with intubation of congenital nasolacrimal duct obstruction. Complications due to intubation persist with the monocanalicular tube. However, some of the complications the authors encountered may be avoided by a recent change in the design of the tubing and by familiarity with recommended techniques. The overall success rate of 79% with the Monoka tube is lower than that for published reports of bicanalicular intubation.

Authors' abstract, Ophthalmol
University of Illinois at Chicago,
Chicago, IL

Pediatrics and Strabismus

PURPOSE: Methods for detecting subnormal vision early in life are needed to adequately diagnose the condition and begin treatment and rehabilitation.

METHODS: Forty-six children ages 1 month to 1 1/2 years with either assumed normal vision, visual impairment due to eye disease, or strabismus were examined with the following tests: Stycar rolling balls; preferential looking (Teller acuity cards); and the ability to detect raisins, puffed rice, and sugar strands on two different backgrounds, one white and one black.

RESULTS: Children with visual impairment and strabismus often showed normal values for their age, and children with assumed normal vision sometimes had values below those established for normal development of vision with the Stycar rolling balls and the Teller acuity cards.

CONCLUSIONS: It is not possible to use these tests to reliably differentiate among normal vision, visual impairment, or strabismus in children younger than 1 1/2. Not until recognition acuity, symbols, or letters can be tested can reliable results be obtained. However, the tests are useful to estimate the general visual function of children in this age group.

Authors' abstract, JPOS
Karolinska Institute,
Huddinge University Hospital,
Sweden.