When DCR tear duct surgery fails: why watering comes back, and what a repeat involves

When DCR fails, the eye waters again mainly because the new opening between the tear sac and the nose has scarred narrow or shut, or because a second blockage higher up the drainage system was missed. A repeat operation is often possible. This article sets out how often DCR fails, how the cause is found, and what a repeat involves and cannot promise.

DCR, short for dacryocystorhinostomy, builds a new tear route from the tear sac into the nose. I describe how it is done in my article on what happens during DCR and recovery, and why tears fail to drain in the first place in my guide to constantly watery eyes. Here the starting point is different: the operation has been done and the eye is still wet.

How often does DCR fail?

Most DCRs work and a minority do not. A leaflet from Leeds Teaching Hospitals NHS Trust quotes 85 to 90 in 100 for external DCR, where success means the watering stops completely or happens only in very windy weather. The same leaflet says failure to cure the watering occurs in fewer than 10 in 100 cases. The two statements are not identical, which is a reminder that the way success is defined changes the number: a much better eye and a completely dry eye are different outcomes.

The route matters less than most people expect. A 2024 meta-analysis of ten randomised trials, 969 patients in all, compared endoscopic DCR, done from inside the nose, with external DCR, done through a small cut beside the nose. Surgical success was similar (relative risk 1.02, 95% confidence interval 0.80 to 1.30). Endoscopic surgery had its own advantages in that analysis, such as shorter operating time and less blood loss, but neither route was immune from failure.

Why does the eye water again after DCR?

The commonest reason is that the new opening, called the ostium, heals smaller than planned or closes with scar tissue. The ostium is a wound made through bone and lining, and wounds heal by scarring. In a 2020 series of 115 eyes that needed a repeat external DCR, the commonest cause of the first operation's failure was an ostium that was too small: 37.9% after external DCR, 36.1% after endoscopic DCR and 66.7% after transcanalicular laser DCR, in which a laser is passed through the eyelid drainage canal. Too small an ostium was significantly more common after laser DCR, and scarring of the ostium after external DCR.

Failure can sometimes be seen coming. A 2022 series of 27 eyes was treated within six months of endoscopic DCR because the opening was heading for failure. The obstruction was a granuloma (an overgrowth of soft healing tissue) in 63.0%, cicatrisation (scar tightening) in 29.6% and synechiae (bands of tissue joining the walls of the opening) in 7.4%. The opening was cleared in a short office procedure with a microdebrider, a small shaving instrument, and every eye had a working system afterwards. It was a small retrospective series from one centre, so it shows what is possible, not what to expect.

The nose can be the cause too. In the 2020 series, 23.5% of patients had a nasal problem, and septal deviation (a bent partition between the nostrils) was the commonest. That is one reason a surgeon looks inside the nose before deciding anything.

What if the blockage is higher up, above the tear sac?

A DCR bypasses a block below the sac, so it cannot help a block above it. That upper part is the canaliculi, the two tiny tubes that carry tears from the lid openings to the sac. In the 2020 repeat-DCR series, canalicular or common canalicular obstruction, nasal pathology and blockage on both sides were each independently linked to failure of a repeat external DCR. A canalicular block that was never found before the first operation is a reason the opening can look healthy while the eye still waters.

How those blocks are found and treated, including silicone tubes and the Jones tube, is in my article on blockage higher up the tear drainage system. A Jones tube is a bypass from the corner of the eye to the nose, used when the canaliculi cannot be rebuilt, and it asks for long-term care of its own.

Could the watering have had a different cause all along?

Yes. Watering means tears are not leaving the eye, or that too many are being made, and DCR treats one cause only. A slack lower lid, a lid turned outwards, a narrowed punctum (the drainage opening on the lid margin), dry eye with reflex tearing and lash problems can all give a wet eye, and a perfect ostium cannot fix them. My view is that the most useful question before any repeat operation is whether the first diagnosis was complete. I set out how to tell too many tears from poor drainage in my article on watery eyes in adults.

How is a failed DCR assessed?

By going back to basics and then looking inside the nose. The repeat-DCR series describe a full eye examination, an examination of the nose, and probing and irrigation of the drainage system. Irrigation, or syringing, means flushing saline through the eyelid openings to see whether it reaches the nose and where it stops. Endoscopy of the nose, using a thin telescope, shows whether the ostium is open, scarred or crowded by granulation tissue.

A functional endoscopic dye test places fluorescein dye in the eye and watches for it to appear in the nose. It shows whether the new route is working, not just whether it is open. The 2022 series defined anatomical success as patent syringing plus a positive dye test. Together these tests separate an opening problem from a block above it, and from watering that was never a drainage problem.

What does a repeat DCR involve, and do mitomycin C or silicone tubes help?

A repeat operation, called revision DCR, reopens or rebuilds the opening and deals with whatever closed it. The Leeds leaflet says a further operation may be possible and may well be successful. In the 2020 series, revision external DCR succeeded in 85.2% of eyes. Whether a revision is done through the nose or through the skin depends on the findings and the surgeon, and it is decided on examination.

Mitomycin C is a drug that slows the cells that make scar tissue, applied to the bone opening for a few minutes during surgery. A 2014 meta-analysis of 15 randomised trials covering 850 procedures (average concentration 0.3 mg/ml, applied for about 18 minutes) found it reduced failure in primary external DCR (risk ratio 0.51) and in revision endoscopic DCR (0.43), but not significantly in primary endoscopic DCR (0.94). Evidence for revision external DCR was lacking. Only two adverse effects were reported, both delayed wound healing. These were small trials, and the numbers describe groups rather than any one eye.

Silicone tubes are soft stents threaded through the drainage canals and left for weeks to hold the opening while it heals. A 2018 meta-analysis of 14 randomised trials with 1,311 DCRs found about a 5% improvement in success with tubes overall (relative risk 1.05, 1.01 to 1.09). The benefit was statistically significant for external DCR (1.08) and not for mainly endoscopic DCR (1.04, 0.99 to 1.09), and the authors asked for more endonasal trials. The fair summary is a small benefit at most, and whether to use tubes is a surgeon's decision for the individual eye.

What can someone expect from a repeat operation?

Expect a reassessment before a date is set, a plan that names the likely cause of the first failure, and the same aftercare as the first time. For DCR in general, the Leeds leaflet describes a nasal spray to loosen crusts, no hard nose blowing for two weeks, and silicone stents removed about six weeks after surgery. The details of a repeat are set by the surgeon.

Expect honest limits too. An 85.2% success rate means about 15 in 100 revisions in that series did not succeed, and the factors listed above predicted those that failed. If the real problem is a canalicular block that no opening can fix, a Jones tube is the usual bypass, with its own commitments.

A hot, red, painful swelling at the inner corner of the eye means the sac may be infected and needs same-day care, as I explain in my article on dacryocystitis. For everything else, ask for the operation note from the first surgery, which records the route, whether tubes were used and whether mitomycin C was applied. More on the area is in the tear duct conditions section and my hub article on why eyes look tired.