The eyes need to be moistened by tears for proper lubrication and protection of the ocular surface. However, if this occurs in excess, tearing or epiphora is produced, causing discomfort to the patient, as the eye is constantly watering and affecting vision.
The lacrimal gland is located in the lateral part of the upper eyelid. It is responsible for producing tears, which are spread evenly over the entire ocular surface with blinking to keep the eye sufficiently moist.
Tearing can occur for two reasons:
- Excess tear production.
- Blockage of the tear drainage channels (located in the tear duct area).
How does tear blockage occur and what can it cause?
Usually the lacrimal obstruction is located at the level of the nasolacrimal duct, where tears are channeled to reach the nose.
The first symptom that patients suffer is usually a partial obstruction of the passage of tears due to inflammation, which causes tearing when it is cold or windy, or when there are air conditioners on, for example. Some people suffer these symptoms after trauma to the face or nose. This causes a closure of the duct through which tears are eliminated. However, in most cases the causes of nasolacrimal duct closure are unknown.
An obstruction in the tear drainage can lead to an infection of the lacrimal sac, resulting in dacryocystitis, better known as LACK. This infection causes, in turn, an inflammation on that side of the face, which can be quite noticeable.
If there is an obstruction of the lacrimal drainage, the tear remains stagnant on the ocular surface and, in order to be evacuated, it will have to do so over the lower eyelid and towards the face, which causes watery eye. In addition, as the tear is stagnant there, it is not clean but usually carries germs that can cause infections on the ocular surface, such as conjunctivitis or keratitis.
How and when to operate the lacrimal obstruction?
Depending on the level at which the lacrimal obstruction is located, the technique to be used will be different, and the objective will be the unblocking and repair of the lacrimal system. It is important that patients who are going to undergo intraocular surgery have a permeable tear duct, since the risk of intraocular infection and loss of the eye increases in these cases (the eye can become infected with dirty tears). The techniques employed will be:
- Dacryocystorhinostomy (DCR). It is an intervention that creates a new tear duct or tear bypass, with a new communication to the nose. It is usually performed under local anesthesia. For a period of time, and so that the drainage is maintained, small silicone tubes are inserted (which are not visible) and then removed when the drainage duct has been formed. There are 3 ways of approaching the lacrimal sac, with different success rates. The first is the external approach, which is performed under local anesthesia and sedation, with a success rate of more than 95% in restoring tear drainage. It is performed through a small incision of about 8mm, practically invisible. The second technique is the endoscopic route and is recommended for patients who do not want the incision. Its success rate is 70%, it is performed under general anesthesia and allows a quick recovery.
- Currently, the most common procedure is the laser operation, performed by transcanalicular route, without incisions, local anesthesia and with a surgical time of 15 minutes. The inflammation is almost imperceptible and the patient recovers very quickly. The success rate is over 70%.
- Dacryocystorhinostomy + Jones tube. It is performed in those patients who suffer from canalicular obstruction that cannot be solved. It consists of placing a special thin glass tube, which communicates the lacrimal lake with the nose. It is the only solution for this situation and sometimes more than one procedure is necessary to achieve satisfactory results.
- Lacrimal punctal unblocking with microsurgery. This technique is intended for the surgical opening of the lacrimal puncta, when they are obstructed. It is a microsurgery, so it is minimally invasive. Local anesthesia is applied and the procedure is performed on an outpatient basis.
In order to choose the best surgical technique, a good clinical examination by the specialist in Oculoplastics and Tear Duct and Ophthalmology is essential. This will analyze the lacrimal system, including irrigation of the lacrimal ducts with a non-traumatic cannula that will determine the degree and exact location of the obstruction. Some cases will require radiological studies, which will provide information on the status of the lacrimal duct.