The canaliculus is dilated to allow the passage of vitreoretinal light probe . This light probe is passed through the superior canalicular and angled inferiorly to avoid trauma to the inferior canaliculus.
The light probe is then advanced into the lacrimal sac and the point of light can be seen endoscopically (8% cases). the light may be diffused by agger nasi cell of which need to be open prior to enter the lacrimal fossa.)
Using the optimal power the laser ablates the tissue of lacrimal sac.
Once the sac is exposed to light probe is withdrawn to avoid damage to common canaliculus. It is replaced c lacrimal probe to tent the sac medially and further widening of the ostium becomes easier. (Rhinostomy is enlarged to 5-8 mm diameter)
Loop of silicone tent can be done but should not be too tight to cause granulation and “cheese wire”through the canal cut.
Role of Laser in Laser assisted endoscopic DCR
Ideal Laser should have:
|CO2 Laser||Argon Laser||ND:YAG Laser||HO:Yag||Diode Laser||KTP-532 Star pluse Laser||Erbium: YAG|
|Poor haemostatic||Good soft tissue ablation||Good soft tissue and bone ablation||Good tissue ablation||Good tissue ablation||Good tissue ablation||suitable but no delivery system.|
|Poor bone ablation||Poor bone ablation||Poor haemostasis||Good haemostatic properties||Good haemostatic||Good haemostana|
|cannot be delivered through optical fibres.||Spatter and requires repeated cleansing of the endoscopy lens.||Single use fibres so up expenses.||No spattering|
Advantages of Endoscopic LASER DCR:
Disadvantages of Endoscopic LASER DCR:
Advantage of external DCR