What is an endoscopic DCR (Dacrocystorhinostomy) procedure?
A dacrocystorhinostomy (DCR) is a procedure to treat excessive tear flow (medically called epiphora) occurring due to a blockage in the nasolacrimal duct.
Tears are generated in the lacrimal gland at the eye’s upper outer margin. Blinking moves tears into small openings in the eyelids called the puncta. From there, they travel via the canalicular system to the lacrimal sac (situated between the nose and the eye) and finally through the nasolacrimal duct, tears get drained into the nasal cavity. Any blockage in this long path can lead to excessive tear outflow. One common reason is a blocked nasolacrimal duct. A DCR procedure creates a direct opening from the lacrimal sac into the nasal cavity to create a direct drainage mechanism.
The evaluation and management of a DCR procedure may involve both an ophthalmologist and an otolaryngologist.
While this duct can get blocked due to several identifiable reasons such as trauma, previous surgery, tumour, or an inflammatory medical condition, it is difficult to identify the underlying cause most of the times.
A physician can perform a number of tests – physical examination, probing and irrigation of canalicular system, placement of dye in the tears that’s then timed for clearance etc – to determine the problem area in a patient suffering from excessive tears. This evaluation is easy, convenient, and can be done in the OPD without requiring any hospitalization of the patient.
While this procedure is more often than not undertaken with the patient in general anaesthesia, it can also be performed under local anaesthesia as per the surgeon’s or the patient’s preference. This surgery can be conducted from an external approach (via facial incision) or from an endoscopic approach (via nose, using a small telescope and instruments). The aim of the surgery is to enable tear drainage directly into the nasal cavity from the lacrimal sac by bypassing the blocked nasolacrimal duct.
In external DCR (performed by an ophthalmologist), the lacrimal sac is reached through a small incision made between the eye and the nose and is opened into the nasal cavity using sutures or stents.
In the more modern endoscopic DCR technique, the same goal is achieved by accessing the lacrimal gland through the nose using an endoscope and small instruments. In it, a part of bone is removed from above the lacrimal sac and a direct opening into the nose is created. Some surgeons may prefer to use stents for a certain postoperative period to maintain the opening.
Actually there are several benefits in the endoscopic approach:
- The pain is nominal and controllable with mild prescription pain medications.
- Low infection risk (some surgeons prescribe post-surgery antibiotics to cover it) after surgery.
- Very important from the patient’s point of view, there is no facial scarring. So aesthetically too, this is a superior procedure.
Unsurprisingly the endoscopic DCR approach to epiphora is now preferred by surgeons.
The possible risks associated with an endoscopic DCR are as follows:
- Bleeding is minimal but in rare cases, it can be more.
- Scarring can occur inside the nose that can block the created opening to cause excessive tear outflow once again.
- In rarest of rare cases, orbital hematoma i.e. bleeding within the orbital cavity can occur, or an eye muscle injury can be sustained. Either can lead to vision loss or double vision.