The Air-Bubble Test for Lacrimal System Patency

VOL. 94, NO.4

561

CORRESPONDENCE

modified J-loop posterior chamber intraocular lens (Sinskey) in order to avoid the stiffer [-loops and the larger or more complex loops of other designs. Because it is not necessary to retract the iris with a hook, excessive manipulation is eliminated. The flexibility of the modified j-loop and the narrow shaft of the Simcoe forceps (25-gauge) make this an extremely smooth one-handed procedure that can be performed in a closed chamber with a minimum of intraocular manipulation. ROBERT L. HARBIN, M.D. Rome, Georgia THOMAS

P.

M.D. Lafayette, Indiana

MATTI~GLY,

REFERENCE 1. Simcoe, C. W.: Lens insertion forceps. Am. Intraocular Implant Soc. J. 6:60, 1980.

The Air-Bubble Test for Lacrimal System Patency

Figure (Harbin and Mattingly). Top, Simcoe posterior lens forceps. Bottom, Insertion of modified J-Ioop posterior chamber intraocular lens.

forceps for use with the Simcoe posterior chamber intraocular lens but never published a report on it (personal communication). He also designed a similar forceps (Storz E2977 S), which is used to grasp the intraocular lens and the superior loop of the Simcoe intraocular lens simultaneously. 1 We prefer to use the

Editor: The interpretation of "The air-bubble test for lacrimal system patency," described by W. L. Broughton and M. E. Lederman (Am. J. Ophthalmol. 93:652, May 1982), is based upon the formation of an air-bubble at the external nares and the lack of resistance to passage of air through the system. We would like to urge caution in interpreting these results because air bubbles may form coincidentally at the external nares where surgical soap has been applied as a result of air leakage around an uncuffed endotracheal tube (Figure). We would, of course, like to emphasize the importance of endotracheal intubation during pediatric nasolacrimal system patency investigation in children under general anesthesia in order to avoid laryngeal spasm and aspiration during the study. The lability of the laryngeal reflex is especially heightened in parenteral dissociative anesthe-

562

A~1ERICA~

JOURNAL OF OPHTHALMOLOGY

OCTOBER, 1982

REFERE~CE

1. Sevel, D.: Insufflation treatment of occluded nasolacrimal apparatus in the child. Ophthalmology 89:329, 1982.

Reply

Figure (Katz and Canfield). Air-bubble formation at the external nares where surgical soap has been applied because of air leakage around an uncuffed endotracheal tube.

sia, which we believe is contraindicated for this procedure. We do not believe that the small amount (0. .5 to 2 ml) of physiologic saline (even when stained with fluorescein) poses a threat to the well-being of the patient when used in nasolacrimal irrigation. It is usually reaspirated by the anesthetist at the end of the procedure or reabsorbed by the respiratory epithelium. Such doses of physiologic saline are instilled into the respiratory systems even of neonates for tracheobronchial toilet. We believe that with the air-bubble test there is a possibility of intravascular injection of air and the attendant complications if an inadvertent false passage is created during the probing and injection of air into an open, vascular channel. Finally, we would also like to point out a previously published report regarding the use of air insuffiation into the nasolacrimal apparatus to open distal nasolacrimal obstruction. Seve}! used pHisoHex at the external nares and noted that airbubble formation indicated that patency had been established. .'\OR\IA:\" x. K. KATZ, M. D. L-\WRE:\"CE J. CA"FIELD, C.R..'\.A. Washington, D. C.

Editor: Dr. Katz and Mr. Canfield emphasize three points: (1) the importance of uncuffed endotracheal intubation; (2) the possible risks inherent with the use of air (Insufflation), including a false-positive test; and (3) previous studies using insufflation techniques. We believe that endotracheal intubation is not absolutely indicated for nasolacrimal duct probing. An experienced operator can easily perform brief probes with minimal anesthesia administered by mask. This may decrease the recovery time, provide greater patient comfort, and possibly decrease potential aspiration by not providing an endotracheal tube wick through the epiglottis. Intubation may be desirable in training circumstances or where prolonged anesthesia is anticipated. We suggested the air-bubble test as an alternative to other methods of determining the patency of the nasolacrimal system. Patients under anesthesia who still maintain spontaneous breathing may indeed have escape of air through the nares and form a bubble after the application of a soapy solution. However, the concurrent production of a bubble during insufflation and the lack of resistance to passage of the air indicate patency of the system. If a soap meniscus cannot be maintained, auscultation of the air as it passes into the nasopharyngeal cavity can be accomplished. We do not believe that an air embolus after inadvertent creation of a "false passage" is a realistic possibility. Careful attention to technique prevents most significant complications, and, if a false passage does develop, inter-