1. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 Dimensions of the Ritleng probe. The blunt inferior end has a lateral opening 5.0 mm above the tip. The hollow probe is 1.0 mm in diameter and has a 0.3-mm slit that runs from the funnel-shaped entrance to the outlet opening. Figure Legend:

2. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 The Ritleng probe. A funnel-shaped opening on the superior end of the probe facilitates introduction of the Prolene thread. A slit measuring 0.3 mm wide runs the entire length of the hollow probe. Figure Legend:

3. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 The Ritleng lacrimal intubation set. Two Prolene (Ethicon Inc, Somerville, NJ) monofilament threads are solidly attached to each end of silicone tubing. Figure Legend:

4. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 The Ritleng lacrimal intubation set. Only the thinner portion of the Prolene (Ethicon Inc, Somerville, NJ) (light blue, 0.20 mm in diameter) can slip out of the open slit of the probe. Figure Legend:

5. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 The Ritleng hook facilitates retrieval of the Prolene (Ethicon Inc, Somerville, NJ) thread from under the inferior turbinate. Figure Legend:

6. Date of download: 6/21/2016 Copyright © 2016 American Medical Association. All rights reserved. From: Ritleng Intubation System for Treatment of Congenital Nasolacrimal Duct Obstruction Arch Ophthalmol. 1998;116(3):387-391. doi:10.1001/archopht.116.3.387 A vertically oriented lacrimal probe in the nasolacrimal duct will tend to press against the mucosa of the lateral wall as it emerges from the ostium. Figure Legend: