"SYRI" - A hands-on teaching model for SYRInging of nasolacrimal duct.

Abstract

Background: Nasolacrimal duct (NLD) screening is a standard before cataract surgery. Lacrimal sac pressure and syringing rules out NLD obstructions.[1] However, lacrimal syringing is invasive and risks iatrogenic injury to the lacrimal drainage system (LDS).[2].

Purpose: Practice model for lacrimal syringing and understanding outflow obstructions.

Synopsis: The model included an inner functional part and an outer mechanical part. Two circular apertures were first made in the ink dropper (lacrimal sac) and two hollow silicone tubing of 10 mm length were glued to the apertures (upper and lower canaliculi). The tubing were bent using pins for the horizontal and vertical canaliculi. Silicone liquid was then poured into 3D-printed mould with LDS model kept inside and was left for 3-4 h. The inner model was modified by fitting small silicone balls, and obstructions were created at various levels such as lower, upper, common canaliculus, and NLD. In normal LDS, when the fluorescein dye passed through one of the tubing, it exited at the NLD opening. If the dye regurgitated through the same tubing, it suggested same canalicular block. Regurgitation from the opposite tubing suggested either a common canalicular block or an NLD obstruction. The model presents a commendable representation of the NLD system; however, it does exhibit some limitations. Notably, the absence of eyelid margins hinders the precise localization of stenotic puncta and the effective utilization of punctum dilators. In addition, the model cannot replicate the lateral pulling of the eyelid, which is crucial for effective probing procedure.

Highlights: Our Do it yourself (DIY) syringing model called "SYRI" is a cost-effective way to practice syringing, enhancing the understanding of canalicular and NLD blocks. While not meant for probing, its repeated use improves proficiency in syringing, benefiting patient care. The model is easily replicated and can serve as foundation for teaching complex surgeries like dacryocystorhinostomy.

Video link: https://youtu.be/xbKl33-W0VA.