How to Perform Lacrimal Syringing and Irrigation скачать в хорошем качестве

How to Perform Lacrimal Syringing and Irrigation

Lacrimal diagnostic probing and irrigation is an anatomical test to examine the patency of the proximal lacrimal system and also the nasolacrimal duct (NLD) using a lacrimal cannula. Use a thin 26G smooth curved lacrimal cannula on a 2.5ml syringe, filled with saline. Diagnostic probing and irrigation of the canaliculi and sac is best performed first through the lower punctum. Always stand on the ipsilateral side that is being probed and irrigated. Ask the patient to look up and gentle pull the medial eyelid down and at the same time, stretch the lower eyelid slightly laterally. Using a 26G lacrimal cannula avoids the need for punctum dilation in the majority of cases, unless punctal stenosis is encountered. Whilst maintaining the lower eyelid slightly everted and laterally stretched in order to stretch and straighten the canaliculus, the lacrimal cannula, attached to the syringe, is inserted into the punctum vertically. Then at approximately 2 mm, the tip is slowly pivoted horizontally to pass through the horizontal canaliculus. Gentle lateral traction is maintained on the eyelid to help straighten the horizontal canaliculus whilst slowly advancing the cannula. Stretching the lower eyelid laterally avoids allowing the canaliculus to kink as the cannula is advanced. Allow the cannula to gently lead rather than pushing with force, and carefully feel for any stenosis or obstruction. Mid-intracanalicular irrigation is performed and careful observation is made to note the proportion, or percentage of this fluid that is regurgitated back, either through the upper canaliculus or lower. In addition, particular attention is also given to the presence of any mucus in this initial return of fluid. The presence of any mucus within this initial fluid return is highly suggestive of some degree of outflow dysfunction of the nasolacrimal duct. The degree of resistance encountered to irrigation is also noted. This is a subjective observation and one that needs some experience in order to determine its correlation with the presence of nasolacrimal duct stenosis (or partial obstruction). However, comparing this to that of the opposite side provides an instant comparison to the clinician, for correlation between the more symptomatic side in unilateral epiphora or where symptoms are greater in one eye. Fluid regurgitation from upper punctum also helps exclude the presence of a complete distal lower canalicular obstruction. Again, stretching the lower eyelid slightly laterally, to straighten the distal lower canaliculus, the cannula is advanced into the sac to very gently touch the medial wall of the sac and adjacent bone. This is described as a hard stop and should be encountered very gently in order not to cause pain. If the sac cannot be entered and a spongy-obstruction, known as a soft-stop is encountered, then firstly, carefully observe for any distortion of the medial canthal angle that may be occurring as the cannula is being advanced. This may be due to a distal lower or common canalicular obstruction. It may also be a fold of mucous membrane found at the junction between the common canaliculus and the lacrimal sac, simply due to a kink approaching the common canaliculus where it turns forward. Avoid this pitfall and false interpretation of a common canalicular obstruction by ensuring the lower eyelid is stretched laterally in order to help straighten this kink and gently feel the cannula tip “explore” the lumen, angled slightly forward. Where a canalicular obstruction is encountered, the length of the lacrimal cannula which can be passed through the punctum should be recorded in order to locate the site of the canalicular obstruction from the punctum. In the absence of a soft-stop, with the tip of the cannula in the sac, then intra-sac irrigation is performed. Careful observation once again, is made to note the proportion of this fluid that is regurgitated back, either through the upper canaliculus or lower. In addition, particular attention is also given to the presence of any mucus in this initial return of fluid. The presence of any mucus within this initial fluid return is highly suggestive of some degree of outflow dysfunction of the nasolacrimal duct. Differences between mid-intracanalicular and intra-sac irrigation help correlate with the presence of a partial distal common canalicular membranous obstruction or stenosis. Informing the patient that intra-sac irrigation with saline is commencing, allows the clinician to gain a subjective qualitative comparison, or a qualitative irrigation transit time between both sides by asking the patient to make a note of when they detected saline reaching their throat. Once irrigation of the contralateral side has been completed, the patient is then asked to report which side was faster. No attempt should be made to overcome any stenosis forcefully so as not to cause a false passage.