Comparison of external versus diode laser conjunctivodacryocystorhinostomy with lacrimal bypass tube placement in proximal canalicular blocks.

AIMS: Hyperlacrimation due to ocular surface or lid abnormality was ruled out and apposition of lower punctum to globe was checked. SUBJECTS AND METHODS: This was a pilot study at a tertiary eye care center where 40 patients of proximal canalicular block <8 mm on probing were divided into two equal groups. The external CDCR group underwent routine dacryocystorhinostomy with partial carunculectomy. A tract was created from canthus to nasal cavity with von Graefe knife. In the laser CDCR group, the osteotomy was created using 980 mm diode laser with a power of 8 W. Glass tubes of appropriate length were placed and fixed using 5-0 polypropylene with our "mirror tuck technique." Results were analyzed using the Chi-square test for parametric and ANOVA test for nonparametric variables using SPSS software.
RESULTS: Success defined as patency on syringing was achieved in 18 patients in the laser group and 16 in the external CDCR group which was comparable (P > 0.05). Complications include tube extrusion, dislocation, conjunctival overgrowth, and sump syndrome.
CONCLUSION: Laser and external CDCRs are both effective and safe procedures for the treatment of proximal canalicular blocks with comparable success rates and complications. Copyright:

Introduction

Conjunctivodacryocystorhinostomy (CDCR) is an acceptable method for the management of proximal canalicular block where a conduit is created between the conjunctiva, lacrimal sac, and nasal cavity through an opening in the lateral nasal wall. To maintain patency of the tract, permanent stenting with tube is performed.[1] The various tube materials that have been tried are silicone, polypropylene, polyethylene, and pyrex.[234]

DCR can be performed by external or endoscopic route. The merits of endoscopic route are avoidance of a cutaneous scar, preservation of the lacrimal pump mechanism, decreased operative time and blood loss, better visualization of the distal end of the tube, concurrent treatment of nasal or paranasal abnormalities, and faster rehabilitation.[5] These advantages can be offered to patients undergoing endoscopic CDCR. Thus, this study was undertaken to compare the outcome of CDCR with lacrimal bypass tube placement performed by external and endoscopic approach using diode laser. To the best of our knowledge, there is no previous study published on this subject.

Subjects and Methods

A prospective, nonblinded pilot study was performed on 40 eyes of 40 patients, >12 years of age, with <7 mm of patent canaliculus, measured on probing, in patients attending the oculoplasty clinic of a tertiary eye care institute between January 2014 and December 2016. Due clearance was obtained from the institute's ethics committee.

Patients with acute inflammation of sac and perisac areas, previous history of facial trauma causing facial abnormality or any condition precluding endoscopy, and other causes of watering such as lid abnormalities and dry eye were excluded from the study. Furthermore, patients with a history of uncontrolled hypertension, coronary artery disease, anticoagulation therapy (warfarin), any past cerebrovascular accident, malignancy or bone disease, collagen vascular diseases like sarcoidosis, Wegener's granulomatosis, pregnant females, and those unwilling for follow-up were not included.

The patients who met the exclusion and inclusion criteria were consecutively divided into two groups, with 20 patients in each arm, after obtaining informed consent from the patient or legal guardian. In a case of bilateral obstruction, only one eye was included in the study.

A detailed preoperative assessment included history of duration, quantity and nature of epiphora, previous surgery (whether symptoms were relieved, postoperative complication if any), any trauma, or systemic illnesses. A general physical and systemic examination was done. To rule out any causes of hyperlacrimation, a complete ocular examination including of assessment of ocular surface, lids, conjunctiva, cornea, anterior chamber was done. Eyelid and punctum position were noted and was the presence of any scar mark, to rule out trauma or previous surgery such as ethmoidectomy, medial orbitotomy. Syringing and probing using a Bowman's probe passed through both the puncta to know the exact site of blockage was done. In posttraumatic cases, X-ray orbit anteroposterior and lateral views, X-ray paranasal sinuses, and computed tomography, if required, were performed. Ear-nose-throat (ENT) examination was done to look for any nasal pathology like hypertrophied turbinates, deviated nasal septum, nasal polyp, cause of reflex tearing like allergic rhinitis, and acute or chronic sinusitis. Routine investigations included complete hemogram, bleeding time, clotting time, and random blood sugar.

The patients were put on nasal decongestant drops (oxymetazoline 0.01%) six times daily and antibiotic eye drops (ofloxacin 0.3%) three times daily 1 week before surgery, and injectable analgesic diclofenac 75 mg i.m and anxiolytic in the form of injection promethazine 25 mg i.m. were administered 15 min before the surgery.

All surgeries were performed by a single surgeon (RG). Group A underwent laser CDCR (laser CDCR) and Group B underwent external CDCR (Ext CDCR) followed by lacrimal bypass tube insertion. Straight glass tubes with a 4 mm cuff, without eyelets, procured from JSIL Scientific Industries, Agra, Uttar Pradesh, were used in the study.

Anesthesia

Local anesthesia comprised local infiltration with 2% lignocaine and 1:200,000 adrenaline at medial canthal area including the periosteum in lacrimal fossa and packing of ipsilateral nasal cavity with ribbon gauze soaked in lignocaine (2%) and adrenaline (1:200,000). A drop of paracaine drops (proparacaine 0.5%) was instilled in the affected eye. General anesthesia was administered to patients <18 years of age.

Procedure

The affected side was cleaned and draped and probing was done to confirm the site of block.

In Group A, the caruncle was partly excised and a tract was created from the caruncle to lacrimal fossa with von Graefe knife [Figure 1]. The fiber-optic cable was introduced through this tract and aiming beam was turned on. The nasal pack was removed and a zero-degree 4 mm nasal endoscope was passed into the nasal cavity and the middle turbinate was identified. The endoscope light was then turned off to visualize the aiming beam at the medial wall of the sac. An osteotomy 6 mm × 6 mm was created at the root of the middle turbinate under direct visualization using 980 nm diode laser (Appasamy Associates, Chennai, India) with a power of 8 W in continuous mode [Figure 2]. The osteotomy was measured by judging the number of times a 2-mm diameter cannula could pass through and a smooth opening was created using a Weil-Blakesley nasal forceps.

Figure 1

Caruncle was partly excised and tract created to lacrimal fossa with von Graefe knife

Figure 2

Osteotomy created at the root of the middle turbinate under direct visualization

In Group B, an incision was made with a No. 11 blade 10 mm from medial canthal angle starting slightly above the medial palpebral ligament and extending downward for an inch and a half. Dissection was carried down to the level of periosteum. The sac was separated from the underlying bone for 5 mm from anterior to the posterior lacrimal crest. The thin lacrimal bone was fractured. An osteotomy of 6 mm × 6 mm was created using Citelli bone punch. The lacrimal sac was laid open and an anterior-based nasal mucosal flap was created. The caruncle was partly excised and a von Graefe knife was passed through the medial angle through the lacrimal sac and into the middle meatus of the nose.

After this step, the procedure of the tube placement was similar in both the groups. A lacrimal probe was passed through the caruncle into the tract created till it hit the nasal septum; the distal end was grasped with forceps and the probe withdrawn. The length of this segment was measured against a scale. Tube sized 2 mm less than this length was placed and the proximal end was sutured with 6-0 polypropylene suture by taking multiple bites into the adjacent episclera and conjunctiva [Figure 3]. The tube was placed [Figure 4] with the lateral end in the tear lake and medial end exposed in the nasal cavity. Patency of the tract was confirmed by disappearance of fluid instilled in the conjunctival sac. Nasal packing was done using a solution of 2% lignocaine with adrenaline 1:80,000.

Figure 3

Tube fixation using 6-0 polypropylene suture

Figure 4

Placement of Jones tube

All patients received systemic antibiotic in the form of tablet ciprofloxacin 500 mg 12 hourly for adults and capsule amoxicillin 10–15 mg/kg body weight 8 hourly in children and ibuprofen 400 mg 8 hourly for 5 days. Topical antibiotics (ofloxacin 0.3%) 6 hourly for 2 weeks and nasal decongestant (oxymetazoline 0.01%) three times daily for 2 weeks were given. Ciprofloxacin ointment was applied 12 hourly till suture removal on the 10th postoperative day in cases of external CDCR. Tablet ethamsylate 500 mg 8 hourly for 3 days was given in cases with inadvertent excessive bleeding.

The patients were followed up for 1 year. Postoperative visits were scheduled on day 1, day 7, every 2 weeks for the first 2 months, and every month for the next 10 months. Syringing was done on each visit and complications, if any, were noted. All data were recorded and tabulated, and statistical analysis was done using SPSS software version 21. (IBM Corp. Armonk, NY). Chi-square test was applied for quantitative and ANOVA test for qualitative data.

Patients were advised not to blow their nose for 2 weeks, following which they could blow their nose with a finger held over the canthal end of the tube. At regular intervals, the tube was flushed and cleaned. Patients were given clear instructions regarding care of the tube, wiping the tube with a cotton tip applicator to remove mucous and regular sniffing and forceful inspiration to maintain patency.

Outcome measure

Primary outcome

Success was defined as patency of tube as observed by disappearance of fluorescein diluted in saline and its recovery on a cotton pledget inserted in the nasal cavity and also patency of the tube on syringing.

Secondary outcome

Patient Satisfaction Index on a scale of 1–5 with 5 being most satisfied [Table 1]

Table 1

Patient Satisfaction Index questionnaire

	1: Very unsatisfied	2: Unsatisfied	3: Neutral	4: Satisfied	5: Very satisfied
Q1 How would you describe the comfort achieved from symptoms like watering, need to mop eyes after the surgery?
Q2. How much are you bothered by the precautions required after the surgery like cleaning the area around the eye, putting finger over the nose while blowing?
Q3. How do you feel about the number of hospital visits required after the surgery?
Q4. How do you feel about the ease of return to normal daily activities immediately after the surgery?
Q5. Occurrence of complications, major or minor (like swelling around the eyes, foreign body sensation, allergic reaction, or tube malpositioning) may be expected in a few cases after surgery. How did these leave you feeling about the surgical procedure?
Rate your response on a scale of 1-5 with 1 being most dissatisfied and 5 being most satisfied
Question	Score
Q1
Q2
Q3
Q4
Q5
Total score out of 25
Final score	Total/5=

Return to work calculated as the number of days taken to resume daily activities.

Results

The study included 40 patients with 18 females and 22 males. The age of the patients varied between 13 and 56 years, with a mean of 37.7 ± 12 years. Overall, the left eye was more involved in both the groups (12 and 13 in Groups A and B, respectively). The mean duration of symptoms was 1.7 ± 1.07 years, with 1.55 ± 0.76 in Group A and 1.85 ± 1.33 in Group B. All patients presented with complaints of watering. On syringing and probing, 39 patients had regurgitation from the same puncta except one who had both upper and lower punctal atresia.

Most cases were idiopathic except two who had congenital punctal atresia and four had posttraumatic canalicular injury.

Intraoperatively, no difference in difficulty was observed. In Group A, two patients had relatively excessive bleeding precluding endoscopic view which was controlled by nasal packs soaked in saline and adrenaline. One of these patients underwent posterior nasal packing by an ENT surgeon. The pack was removed after 48 h, and no fresh bleeding was encountered thereof. In Group B, severe bleeding occurred intraoperatively in two patients, which subsided with a single dose of injection ethamsylate 250 mg.

Postoperative complications were divided into early, occurring within 2 weeks and those later than that. Early complications included periorbital edema in two eyes in Group A and four eyes in Group B that resolved with cold compression and anti-inflammatory drugs (tablet serratiopeptidase 10 mg three times daily and tablet ibuprofen 400 mg three times daily). Periorbital ecchymosis occurred in one patient in Group B which resolved in a week.

Late complications comprised foreign body sensation in three patients in Group A and two patients in Group B. Extrusion of the tube occurred in three eyes in Group A at 1st, 4th, and 7th months. In Group B, tube extruded in four eyes at 4th, 5th, 7th, and 8th months. These patients presented with closed tracts such that the tube could not be placed again.

Dislocation occurred in one patient in each group. In Group A, the tube had dislocated laterally at the end of 3 months. The remnants of the sac acted as a nidus for infection and subsequent development of sump syndrome [Figure 5]. The patient was given a course of systemic and topical antibiotics and the tube was removed for 2 weeks. After resolution of the infection, the tube was replaced. One patient in Group B presented with watering and discharge after 4 months of surgery and the lateral end was felt in the tract, the tube having retracted medially. It was repositioned in the operation theater and the patient remained asymptomatic henceforth.

Figure 5

Tube malposition with coexisting periorbital edema

Conjunctival overgrowth was seen in two patients in Group A and three patients in Group B. In Group A, the patients presented at the 5th and 6th months, respectively. In Group B, the time of presentation after surgery was at the 5th, 7th, and 9th months [Figure 6].

Figure 6

Graph showing a comparison of complications between the two groups (Conj: Conjunctival)

Outcome measures [Table 2]

Primary outcome: The success rate was 85% for Group A and 80% for Group B which was comparable (P = 0.67 by Chi-square test)

Secondary outcome: A Patient Satisfaction Index was calculated where they rated their experience on a scale of 1–5 with 5 being most satisfied. The index for Group A was 3.35 ± 1.2, whereas for Group B, it was 3.05 ± 1.07 (P = 0.4 by ANOVA test).

The return to work was calculated as the day postoperatively the patient was able to resume routine daily activities. It was 5.3 ± 1.6 days for Group A and 8.5 ± 2.1 days for Group B (P = 0.0001, ANOVA test).

Discussion

CDCR is the standard treatment for proximal canalicular blocks where sufficient canaliculus is not available for reconstruction. The first description of CDCR was given by Von Hoffman in 1904.[6] With the advent of modern endoscopic techniques, the endonasal route of DCR gained acceptance. The 980 nm diode laser was reported first by Eloy et al.[7] and is the most widely used laser in CDCR now as it is possible to deliver a sufficiently powerful laser beam through a relatively narrow optical fiber. It achieves effective tissue dissection with minimal collateral damage with results similar to neodymium-doped yttrium aluminum garnet laser at lower cost, hence the same has been used in our study. The advantages of laser surgery are decreased operative time, absence of cutaneous scar which is a boon for keloid-prone individuals, concurrent treatment of intranasal pathologies, decreased blood loss, and better positioning of the Jones tube.[8]

In our study, the mean age was 37.7 ± 12 in Group A and 30.9 ± 14.7 in Group B (P = 0.136). There were 22 males and 18 female patients. The mean duration of symptoms was 1.55 ± 0.76 years in Group A and 1.85 ± 1.33 years in Group B (P = 0.27). We did not find any correlation between success of surgery and gender or duration of symptoms. Correlation between age of the patient and success was suggested by Rosen et al. who found lower success rates in patients younger than 19 years or older than 70 years.[9] This was reiterated by Lim et al. who operated seven cases below the age of 25 years and had only one successful result.[10] In our series, there were eight patients below the age of 25, of whom one had extrusion and one had tube displacement resulting in a complication rate of 25% (2/8) that could be attributed to better compliance to postoperative self-care.

With regard to etiology, a maximum number of cases were idiopathic (34 patients). Two patients had congenital bilateral punctal atresia and four patients were of posttraumatic canalicular injury. Interestingly, all were male which is in concordance with Lim et al. Although not seen in our series, a relation between etiology and rate of success has been hypothesized. Rose and Welham[11] had the best outcomes with postherpetic and Lim et al. with posttraumatic cases.

Although increased manipulations during endoscopy in Laser CDCR are expected to induce the formation of synechiae, this was not seen in any of our patients. This could be attributed to an experienced surgeon. Trotter and Meyer reported one case (out of 13) of nasal adhesions being formed after surgery.[12]

We used 8 W power to make the osteotomy. This is similar to Alañón Fernández et al. who used a 980 mm diode laser.[13] According to them, a power higher than this would cause loss of transillumination of the guide light and thus the orientation of the osteotomy site. The guide light is a very important component of the laser system as it indicates the site of laser application. The thin lacrimal bone can be identified by the area of maximal transillumination [Figure 7] and hence correctly positioned osteotomy is performed. Their size of osteotomy (5 mm diameter) was nearly similar to our study (6 mm diameter). This is unlike external DCR where a large 10–12 mm osteotomy is preferred as a smaller osteotomy provides a snug fit to the tube and resists tube displacement.

Figure 7

The thin lacrimal bone can be identified by the area of maximal transillumination on endoscopy

We had conjunctival overgrowth in four patients between the 4th and 7th months in both the groups. Fan et al. reported similar complication in the 3rd month with the use of Medpor-coated tube.[1] Devoto et al. also noted this complication in three of 55 patients.[14] Both these studies also reported pyogenic granuloma which we did not find in any of our cases. We excised the overgrown conjunctiva and applied a cotton pledget soaked with mitomycin C 0.02% for 3 min and did not observe any recurrence. In patients who presented immediately after tube extrusion, the tube was simply replaced in the preformed tract and fixed with a suture, but those with extrusions more than a week old had the tracts already closed. This was similar to the study by Devoto et al. who had seven migrations, out of which four patients had presented within 5 days of onset of watering and the tube was repositioned under topical anesthesia as an in-office procedure. The other three were seen after a week and permanent closure of the tract was diagnosed. Dailey and Tower[15] followed up 10 patients from 1 month to 14 years. The patients were instructed to report to the office as soon as possible in the event of tube dislocation to enable tube replacement. Thus, close follow-up is mandatory to avoid tract closure.

To decrease extrusion and malposition, for resurgery, we used 6-0 prolene suture to fix the tube to the conjunctiva using a new "mirror tuck technique" which improved the stability of the tube to 97.5%.[16] Chang et al. described a method of encircling suture with 6-0 prolene for preventing tube displacement and compared it with 5-0 vicryl purse-string suture and 6-0 nylon suture which served as a control group. They reported a statistically significant difference between the groups with extrusions in the three groups being 7.7% for the new method versus 21.6% for vicryl and 31% for the control group.[17]

One patient had tube dislocation with development of "sump syndrome." She underwent tube removal and refixation later and further had an uneventful course. This might be due to the presence of a potential space in the lower portion of the sac with the opening created at a higher level in laser CDCR unlike external CDCR where actual anastomosis is created. We have encountered a similar case previously which we managed the same way.[18]

The placement of the tube in our case was at the medial canthal angle with partial carunclectomy. Removing the caruncle creates adequate space to accommodate tube collar and prevent tissue crowding that can block the proximal tube end. Leaving the posterior, half of the caruncle in place protects the medial bulbar conjunctiva from inflammation due to contact with Jones tube orifice.[19] Abel and Meyer reported two cases of refractory conjunctival inflammation[20] in patients without carunculectomy, for which one patient underwent excision of the granulation tissue with amniotic membrane graft and replacement of the tube. The other patient had persistent conjunctival injection despite tube removal. Histopathological examination revealed fibrosis of the conjunctiva. They postulate that the chronic effect of the presence of Jones tube coupled with surgical manipulation, especially in multiple procedures, may predispose to this response. In our case, only one patient had medial conjunctival injection that resolved by 1 week on topical antibiotics and topical anti-inflammatory drugs and did not recur.

The final outcome of patency on syringing in both the groups was comparable with P = 0.67. However, the laser group had a better Patient Satisfaction Index due to better cosmesis (P = 0.4) and recovered faster with a much shorter "back to work" duration which was statistically significant (P = 0.0001) [Table 2]. The drawback in the laser procedure is the high initial cost of setup and the learning curve though once the skills of endoscopy are mastered, the surgeon is rewarded with reduction in operating time. External CDCR has the added advantage of performing concurrent canthal procedures [Figure 8] like telecanthus repair which may occur in posttraumatic cases. In laser CDCR, telecanthus needs to be repaired beforehand as it may lead to tilting of tube. The limitations of our study are a small sample size and short follow-up.

Table 2

Comparison of outcomes of laser versus external conjunctivodacryocystorhinostomy results

	Group A (laser CDCR)	Group B (external CDCR)	P
Early complications
Periorbital edema	2	4	0.376
Ecchymosis	0	1	0.311
Late complications
Foreign body sensation	3	2	0.633
Tube extrusion	3	4	0.677
Sump syndrome	1	0	0.311
Conjunctival overgrowth	2	3	0.633
Success rate (%)
Primary outcome (patency)	17/20 (85)	16/29 (80)	0.67
Secondary outcome
Return to work (days)	5.25±1.58	8.45±2.1	0.0001
Patient satisfaction index*	3.35±1.2	3.05±1.07	0.4

*Rated on a scale of 1 to 5, 5 being most satisfied. CDCR: Conjunctivodacryocystorhinostomy

Figure 8

Patient who underwent canthal repair and Jones procedure in the same sitting

Conclusion

Laser and external CDCRs are both effective and safe procedures for the treatment of proximal canalicular blocks. The outcomes of both the procedures are comparable with each having its advantages. Laser CDCR is faster and avoids all the complications of a cutaneous scar with early rehabilitation of the patient but is machine dependent. External CDCR is easier to master for those well versed with external DCR and concurrent canthal surgery can be done with the same incision.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.