ENDOSCOPIC DACROCYSTORHINOSTOMY (DCR)
Endoscopic surgery is recommended in the treatment of tearing due to nasolacrimal duct obstruction. In children, blockage of this duct can result from the failure of a membrane at the end of the tear duct (Valve of Hasner) to open normally at or near the time of birth. In adults this can result from inflammatory medical conditions, trauma or a tumour. However, it most commonly occurs without an identifiable cause.
Tear duct obstruction can be diagnosed by looking at a patient’s history of tearing and discharge at a very early age. One of the major factors in determining the success rate of endoscopic dcr surgery is the level of obstruction in the lacrimal drainage system.
The nasolacrimal duct is a small tube that connects the eyelids to the inner nose, and has the role of acting like an inner drainage tube or ‘gutter’ for tears. One’s eyes need lubrication - the function of tears. This lubrication needs to be regularly changed, so tears are continually produced and the excess goes down the nasolacrimal duct into the nose.
This duct can get blocked, resulting in tears welling out of the eye down the cheek, especially with cold weather. The problem is normally observed by the eye specialist (Ophthalmologist) first, who will ensure that the concern is not related to any other eye related condition. Traditionally they would repair the obstruction in the nasolacrimal duct by operating externally through an incision on the cheek, between the eye and nose.
Today the operation is usually performed by an ENT (ear, nose and throat) surgeon who is trained to do the whole operation through the nose, thus avoiding the need to make any cuts on the face. The endoscopic dcr operation is done under general anaesthesia, as a day-care case (in and out the same day), and takes about forty five minutes. The objective of the procedure is to bypass the obstructed nasolacrimal duct and allow for tear drainage into the nose directly from the lacrimal sac.
There is normally a little tube inserted as a stent in the nasolacrimal duct which is left in place for some 6 weeks before being removed painlessly in the doctor’s rooms.
The endoscopic approach ensures that pain is minimal and can be controlled with mild prescription pain medication. Infection is uncommon, but many surgeons prefer to administer antibiotics. There is no bruising or external evidence that surgery has been performed. The endoscopic dcr technique is a safe, effective, low complication technique that yields good aesthetical-functional results and shows a success rate similar to that of external approach when performed by experienced surgeons. Other advantages include:
- It allows a one-stage procedure to also correct associated nasal pathology that may be causative
- It is less bloody and messy than the external approach.
- The success rate is comparable to the external approach.
- It provides a better aesthetic result with no external scar
- It preserves the pumping mechanism of the orbicularis oculi muscle.