Watery eyes, also known by the medical term epiphora, occur when excessive tears drain from the eyes.
This may seem common, but can watery eyes ever indicate a serious medical condition like cancer? And when should you see a doctor? We spoke with ophthalmologists Nagham Al-Zubidi, M.D., and Dan Gombos, M.D., for answers to these questions and more.
How do our tears drain normally?
Tears are produced by the lacrimal glands in the eye socket.
“In the inner corner of the eye are two small openings called puncta, and they are connected to a smaller tube called a lacrimal duct,” explains Al-Zubidi. “The lacrimal duct drains into a small sac called the nasal lacrimal sac, which then goes through the nasal lacrimal duct, a drain into the nose.”
This is the natural way tears drain: through the nose, not down the face.
“Your eyes are watering either because the structure that makes the tears is overproducing or the drainage system is underperforming,” says Gombos.
What causes watery eyes?
Common causes for watery eyes can include:
infection, like conjunctivitis (pink eye)
trauma, such as a bone injury near the eye
Are watery eyes a symptom of cancer?
Watery eyes can be a sign of cancer, says Gombos. “Cancer can involve the system producing tears, but more commonly the cancer involves the drainage system, so the tears don’t drain properly,” he adds.
However, watery eyes alone don’t correspond directly to a particular type of cancer, and the presence of watery eyes doesn’t predict the severity or stage of cancer, say both Al-Zubidi and Gombos.
Primary tumors can occur in the lacrimal system or in structures around the eye, such as the nasal cavity and sinuses, eyelid or skin. These tumors can be benign or malignant. Anything obstructing these systems can cause watery eyes.
Watery eyes could be a symptom of the following cancers:
increase in severity over the course of a few days or
do not improve within three to four weeks.
How does an ophthalmologist reach a diagnosis?
“You’ll undergo a full ophthalmology exam in the clinic, which includes a physical examination of the eye and an ocular motility test,” says Al-Zubidi. “Then, you’ll have an MRI, which allows us to see the brain and eye socket, because some tumors have very specific radiographic findings on an MRI or CT scan. This also helps show the extent of any tumors.”
If the doctor finds any tumors, sometimes they’ll order a biopsy, so the pathologist can examine the cell tissue of the mass and determine if it’s cancerous or not. You may also have a full body screening to ensure no cancer has spread to other parts of your body. This includes a PET scan and CT scan of the head, chest, abdomen and pelvis.
“Not every patient will need a biopsy,” says Al-Zubidi, “but if cancer is suspected, we always do a biopsy to confirm.”
Oculoplastic surgeons are ophthalmologists who specialize in plastic and reconstructive surgery of the eye and facial structures around the eye. If you are diagnosed with cancer in one of these areas at MD Anderson, an oculoplastic surgeon may be part of your care team.
Are there other ways watery eyes can be related to cancer?
Chemotherapy may cause watery eyes in some patients with cancer. The chemotherapy drugs paclitaxel and docetaxel can cause nasal lacrimal duct obstruction, say Al-Zubidi and Gombos. In recent years, the dosing for docetaxel has been altered to reduce this side effect.
“Radiation in the head and neck area can also be a cause of watery eyes,” says Gombos. “So, in addressing watery eyes, we first need to determine if the patient has a history of cancer, and we need to know the treatment used to manage the cancer.”
For established patients who have already had some form of therapy – typically chemotherapy and/or radiation – more often than not, watery eyes are a side effect from that. These side effects can appear weeks, months or even years after therapy.
Can watery eyes be treated?
The cause of watery eyes determines the treatment.
“If it’s cancer, we either surgically remove it or treat it with chemotherapy, targeted therapy or radiation therapy,” says Gombos. “Sometimes after treating the cancer, with radiation or docetaxel, for example, there will be a secondary impact. This can involve not enough tears, which we supplement with lubrication. Or it can be inadequate drainage, in which case we would create a conduit for the tears to go. We basically create a hole from the eye to the nose, so the tears can drain properly.”
It’s important to see a doctor if your watery eyes persist.
“Don’t ignore it and think, ‘I just have to live with it,’” says Gombos. “There are many noncancerous issues related to watery eyes, so it’s best to determine the cause and get relief as soon as possible.”