Canaliculitis is a rare lacrimal disease characterized by epiphora with discharge, pouting punctum, pus and redness. In our study, the incidence of canaliculitis showed a female predominance which was consistent with previous studies.[10, 17] The female predominance may be due to use of cosmetics which can occlude the lacrimal duct. In addition, menopausal hormone changes may decrease tear production and reduce protection against infections.[9, 17]
All the patients involved were unilateral, which is the same with most of the studies.[12, 18, 19] Very few patients involved bilaterally.[20, 21] In our study, affection rate of the upper punctum and the lower punctum was the same, while in other studies, the lower punctum was affected more frequently. Lin et al reported a predominance of lower canaliculitis up to 73%.[7] In a study with a larger sample size, the lower punctum was also more vulnerable (68%).[20]
Epiphora with discharge and presence of concretions under compression were the typical symptoms and signs of canaliculitis in our study, which emphasized the importance of concretions in canaliculitis disease process. Xiang et al summarized 37 primary canaliculitis patients, 36 of them (97.3%) showed concretions.[22] Other studies indicated that the rate fluctuated between 73% and 100%.[8, 23, 24]
Both punctum-incised surgery and punctum-sparing surgery are effective treatment of canaliculitis. Stucki performed punctum-incised surgery on 10 patients and only one had recurrent canaliculitis.[18] Khu performed punctum-sparing surgery by making an incision 2mm medial to the punctum on three patients, and none of them showed recurrence.[16] A monocanalicular stent was used instead of suture in Khu's surgery and the incision was left to heal by secondary intention, which was different from our study. In our study, 3 patients showed recurrence (5%). 2 patients were from the punctum-incised group (4%) and 1 patient was from the punctum-sparing group (9%). The clinical information of the three patients were summarized in Table 2. Both punctum-incised surgery (9%) and punctum-sparing surgery (5%) were effective. There was no significant difference between the two methods(p=0.514). Whether incising the punctum or not had no difference in the recurrence rate. In our opinion, thoroughly concretion cleaning might be the key point in the surgery. As for other recurrence risk factors, being male and presence of concretions were reported, but these were not observed in this study.[7, 25]
All 3 recurrent patients were both upper and lower puncta involved. As for patient A, we got sulfur-like concretions from his upper canaliculus using tweezers while no concretion was found from his lower punctum, which only showed little pus under syringing. Based on this examination, we performed surgery only on his upper punctum. One week after 3-snip surgery on his upper canaliculus, sulfur-like concretions showed from his lower canaliculus under squeezing. So, we operated on his lower canaliculus and he didn't show any sign of recurrence on both puncta. Thus, false negatives may occur when using tweezers to locate concretions, not all the sulfur-like concretions can be detected by using tweezers. Patient B and C shared similar situations. No sulfur-like concretion was found under compression in lacrimal ducts. As for patient B, no sulfur-like concretion was captured from her lower punctum by compression at her first visit. So only her upper punctum was incised during the first operation. In her 2-month follow up, she relapsed. Lower lacrimal duct infection without concretion was considered to be responsible for the recurrence. Punctum-incised canaliculotomy was performed on her lower lacrimal duct during her second operation and she fully recovered. Patient C relapsed 3 months after upper and lower punctum-sparing canaliculotomy. He received a lower lacrimal duct canaliculotomy and recovered in one week after the second operation. Thus, both patients were diagnosed primary canaliculitis and were treated through canaliculotomy. No sulfur-like concretion was found in their lacrimal ducts. Sulfur-like concretion may be concealed or absent in canaliculitis.
In previous studies, lacrimal duct pressing was considered as an important examination as well as treatment, which was usually done by cotton swabs instead of tweezers.[2] In our study, tweezers were used to squeeze the punctum and the lacrimal duct to locate the concretions under local anesthesia (0.4%Benoxil, Santen). Using tweezers to clamp is more precise than using cotton swab and the former action provides more pressure which may improve the detection rate. We have done squeezing on 18 patients and 16 of them showed concretions extruding from a certain punctum. Tweezers-squeezing was useful in assisting diagnosis and a reliable examination to locate the concretion and the lesion. However, not all the concretions can be detected. Absence or concealment of concretions may be the possible reasons.
Previous studies reported other tools like ultrasound and lacrimal endoscopy to assist diagnosis. Ultrasound with 20-Mhz or 80-Mhz has been used to diagnose in patients with atypical clinical presentations.[22, 26] Besides, lacrimal endoscopy was reported as a useful tool to examining the lacrimal duct by direct visualization. Zheng et al performed endoscopy on 12 patients for both examination and treatment, all 12 patients got complete recovery.[2]
Regarding the punctum choice, surgeries should be performed on the side of punctum which showed concretions by compression. If there is no concretion, surgical treatments should be performed based on clinical symptoms such as pouting punctum and palpable thickened canaliculus.[8, 10] However, it was possible that some lesions were hard to locate. In this scenario, patients should be informed risks of partial resolution or recurrence. As a result, patients who presented symptoms on punctum but showed no sulfur-like concretion under squeezing or syringing were more likely to be non-responsive from the treatment. Ultrasound and endoscopy could be alternative examinations to evaluate which punctum should be treated for these patients.
The Riolan muscle inserts into the punctum and pulls the punctum medially and posteriorly, which helps maintain the shape and position of the punctum and the lacrimal pump function.[27] In punctum-sparing surgery, the Riolan muscle and the connective tissue around the punctum were intact. Therefore, punctum-sparing surgery may preserve the lacrimal pump function. Whereas previous studies reported that epiphora and lacrimal pump dysfunction occurred after punctum-incised surgery.[12] Only a few patients with lacrimal duct obstruction pre-surgery showed epiphora post-surgery in our study. One patient showed focal adhesion around the punctum one week after punctum-sparing surgery on both puncta. The adhesion was loosened and completely alleviated in the follow-up. Other complications were not observed in this study.
Monocanalicular stent was used in previous punctum-sparing surgery to help reestablish the canalicular anatomy and avoid post-surgery epiphora.[16] However, monocanalicular stent wasn't used in our surgeries and no canalicular scarring or outflow obstruction was observed in this study. In our perspective, monocanalicular stent may not be essential in this operation.
There were some limitations in our study. Firstly, the sample size was relatively low in punctum-sparing group. Secondly, squeezing by tweezers was a good examination and could provide guidance for surgical treatment, but not all the concretions can be detected in this way and canaliculitis can develop without concretions. So surgical decisions may be misled, and partial resolution or recurrence would appear. For patients with atypical symptoms that cannot be detected by tweezers clearly, endoscopy and ultrasound might be backup choices.
Table 2
Specific treatment of the patients who showed recurrence.
| Patient A | Patient B | Patient C |
Age (Years) | 80 | 84 | 70 |
Gender | Male | Female | Male |
Time to diagnosis (months) | 6 | 60 | 12 |
Laterality | Left | Left | Right |
Location | Both | Upper | Both |
Symptom | Upper: sulfur-like concretions Lower: little pus | Upper: pus, punctal regurgitation | Both: Pus |
1st Treatment | Upper, punctum-incised | Upper, punctum-incised | Both, punctum-sparing |
Recurrence time# | 1 week | 2 months | 3 months |
Recurrence sign | Upper: little pus Lower: sulfur-like concretions | Both: Epiphora with discharge | Redness |
2nd Treatment | Both, punctum- sparing | Lower, punctum-incised | Lower, punctum- sparing |
2nd Recurrence | | | 1 week |
3rd Treatment | | | Remove the suture |
#Recurrence means the time between the surgery to the symptom reoccurred