A Comparison between Placement of three interrupted sutures after Triangular Three-snip Punctoplasty vs conventional Triangular Three-snip Punctoplasty for treatment of lower punctal stenosis

Aim is to evaluate surgical outcome of Triangular Three-snip Punctoplasty (TSP) with three interrupted sutures and compare it to conventional Triangular Three-snip Punctoplasty (TSP) in treatment of acquired lower punctal stenosis. Methods This prospective study included 40 eyelids of 24 patients with acquired lower punctal stenosis grade 1 or grade 2 were classied in two groups. Group A was treated by triangular 3-snip punctoplasty of the lower punctum followed by three interrupted sutures at the posterior ampulla and group B was treated by conventional triangular 3-snip punctoplasty of the lower punctum. Grade of epiphora and grade of FDDT were measured preoperative then post-operative after 1 week, 1 month, 3 months and 6 months. Success was dened as postoperative improvement of epiphora and FDDT grading with no restenosis to occur.


Introduction
Punctal stenosis is a common disorder affecting the punctum and accounts for 8% of all cases with epiphora. Kashkouli et al., proposed a grading system for the puncta based on its size and shape. Grade 0: No punctum (agenesis) Grade 1: Papilla is covered with a membrane (di cult to recognize) Grade 2: Less than normal size, but recognizable Grade 3: Normal Grade 4: Small slit (< 2 mm) Grade 5: Large slit (≥ 2 mm ( [1,2] However, there is no acceptable universal guideline for the management of punctal stenosis. Several modalities described in the literature including punctal dilatation, 1-snip punctoplasty, 2-snip punctoplasty, triangular 3-snip punctoplasty, rectangular 3-snip punctoplasty, 4-snip punctoplasty, punctal punching with Kelly's or Riess punch, punctoplasty with mitomycin-C, and inserting perforated punctal plugs, self-retaining bicanalicular stents, or mini-monoka. [2][3][4][5][6][7][8][9][10] The triangular 3-snip in its traditional form is based on one cut in the vertical canaliculus, one in the horizontal canaliculus and one cut at the base [11]. The current study examines the role of placing 3 interrupted sutures at posterior wall of the ampulla after triangular 3-snip punctoplasty in achieving successful outcomes and preventing re-approximation of the cut ends in cases of acquired lower punctal stenosis. [12] Patient And Methods This is a prospective randomized study which included 40 eyelids of 24 patients with acquired lower punctal stenosis grade 1 or grade 2 according to Kashkouli scale. Patients included in the study were recruited from Menou a University hospitals in the period from January 2019 to June 2020. Informed consent was obtained from all patients, and the study was approved by the institutional review board. All measures were in accordance with the tenets of the Declaration of Helsinki.
All patients of the study were complaining of epiphora which was graded according to Munk score as follows; grade 0: no epiphora, grade1: occasional epiphora requiring drying or dabbing less than twice a day, grade3: epiphora requiring dabbing two to four times per day, grade4: epiphora requiring dabbing ve to 10 times per day & grade 5: epiphora requiring dabbing more than ten times daily or constant tearing. [13] Patients were classi ed in two groups. Group A patients were treated by triangular 3-snip punctoplasty of the lower punctum followed by three interrupted sutures at the ampulla. Group B patients were treated by conventional triangular 3-snip punctoplasty of the lower punctum.
Inclusion criteria included; primary acquired lower punctal stenosis grade 1 or 2 according to Kashkouli grading, with patent upper punctum and both canaliculi as well as patent nasolacrimal duct revealed after syringing, with normal lower eyelid margin position.
Exclusion criteria included; Patients with Congenital punctal stenosis, Acute conjunctival allergic punctal stenosis, Punctal stenosis associated with radiotherapy, Lid malposition, Canalicular, lacrimal sac and nasolacrimal duct obstruction revealed after syringing, Previous eyelid or lacrimal drainage system surgery, Blepharitis and ocular surface disorders, Patients with dry eye.
A full history was taken and thorough ophthalmological examination was done for all patients including evaluation of proximal lacrimal drainage system regarding punctal ori ces position, shape, grading of stenosis according to Kashkouli et al and exclusion of other causes of epiphora rather than punctal stenos. Inspection of face and periorbital region for position of the eyelids and puncta, Gross nasal deformity, Facial symmetry, presence of any swelling or stula in the lacrimal sac area , palpation of lacrimal sac for regurge test , slitlamp examination of eyelid margin for coaptation with the globe , blepharitis or rubbing lashes , skin for laceration or eczema , conjunctiva for papillae , follicles, hyperemia or discharge , cornea for punctate keratitis, laments or abrasions , lower Tear meniscus height (TMH) using a 1 mm slit beam.
Fluorescein dye disappearance test (FDDT) where a drop of sterile 2% uorescein solution or a moistened uorescein strip is instilled into the conjunctival fornices and tear meniscus was observed after 5 minutes with the help of cobalt-blue lter and results were graded according to Ozgur et al., scale depending on the time of dye clearance as follows; grade1 (<3 minutes), grade2 (3-5 minutes) & grade3 (>5 minutes). [14] Diagnostic probing and syringing were done to ensure anatomically patent nasolacrimal system and to detect any obstruction distal to the punctum.

Surgical technique
Surgery was performed using an operating microscope under local anaesthesia. We transconjunctivally in ltrate 2% (w/v) lidocaine (with epinephrine in a 1:100,000 weight ratio) from the posterior aspect of the eyelid into the region of the lacrimal canaliculus and punctum. A Nettelship dilator is used to enlarge the stenotic lacrimal punctum. A single blade of a small Westcott spring scissor or Vannus scissor is placed within the ampulla of the lacrimal canaliculus, with the remaining blade placed on the conjunctival surface of the posterior aspect of the eyelid. The rst vertical snip is made at the vertical canaliculus. The second vertical snip is made from the edge of the rst snip to create a ap. The nal horizontal snip was made at the base. The triangular ap is removed and three sutures are placed, in an interrupted manner, at the posterior wall of the ampulla using 10-0 nylon. The sutures are removed 1 week after the surgery. Topical moxi oxacin 0.5% eye drops and uorometholone 0.1% eye drops were used four times daily for one week.
Patients were examined in visits at one week, 1 month, 3 months and 6 months for patency of the lower eyelid punctum, FDDT grade and Munk score of epiphora.
Satisfactory surgical outcome was de ned as postoperative patent lower eyelid punctum and improved Epiphora score and FDDT grade at 6 months after surgery.

Results
Forty eyes of 24 patients were enrolled in the study, including 20 eyes in group A and 20 eyes in group B. There were 6 (30%) men and 14 (70%) women in Group A and 7 (35%) men and 13 (65%) women in Group B. The mean age of patients in group A was 59.25 ± 10.50 years, while the mean age in group B was 58.75 ± 10.68 years, with no statistically signi cant difference between both groups regarding gender and age distribution.

Discussion
The anatomical principle of punctoplasty is to widen a stenosed punctum constantly and bring the widened punctum near the tear meniscus. The posterior wall of the vertical canaliculus needs to be excised to achieve these aims. The raw edges are not in contact and this prevents immediate healing and restenosis of the punctum.
However, anatomical recurrence and restenosis was observed in some cases who underwent conventional 3 snip punctoplasty, thus placing 3 interrupted sutures at the posterior ampulla was rst introduced by Park et al. 2018 to improve the outcomes of the conventional 3 snip punctoplasty. [12] In 2018, Park et al.'s proposed a modi cation in the conventional 3 snip punctoplasty by placing 3 interrupted sutures in a trial to prevent or decrease the restenosis rate. They reported, after 17-months follow-up period; anatomical success rate of 91.7% (44 of 48 eyes enrolled), and four eyes (8.3%) remained unchanged. Among the four eyes (8.3%) who were determined as symptomatic failure, anatomical recurrence (restenosis of the punctum) was observed in only one eye (2.1%) and the other three eyes (6.2%) had post-operative functional epiphora.
Authors of the current study adopted this modi cation in group A patients. And in spite of the shorter follow up period (6-months); anatomical success was observed in only 80% of cases (16 of 20 eyes enrolled); while four eyes (20%) remained unchanged. Among the four eyes, determined as symptomatic failure, anatomical recurrence (restenosis of the punctum) was observed in only two eyes (10%) and the other two eyes (10%) had post-operative functional epiphora.
On comparing placing 3 interrupted sutures to conventional 3-snip punctoplasty; placing 3 interrupted had better functional and anatomical results. Subjective improvement of epiphora using Munk score was better in group A. Also, FDDT indicated objective functional improvement. By the end of the follow up period, FDDT was grade 1 in 10 eyes (50%), grade 2 in 8 eyes (40%) and grade 3 in 2 eyes (10%) in group A. On the other hand, in group B it was grade 1 in 6 eyes (30%), grade 2 in 10 eyes (50%) and grade 3 in 4 eyes (20%). 18 eyes (90%) among group A versus 15 eyes (75%) in group B improved regarding FDDT grade with signi cant difference.
Anatomically, restenosis occurred in 2 eyes (10%) in group A while it occurred in 4 eyes (20%) in group B by the end of the follow up period. This may be attributed to the fact that the interrupted sutures help to decrease the raw surface of the dilated punctum and making restenosis of the dilated punctum less likely [12]. However, the present study showed higher anatomical recurrence rate in both groups. This may be explained by the prevalence of trachoma in Egyptian patients rendering them more vulnerable to cicatrization.
As regard safety, both techniques were well tolerated with no intraoperative or postoperative complications apart from foreign body sensation that was felt in 100% of eyes in group A during the early postoperative period and disappeared after one week when stiches were removed. This complaint was not present in patients of the other group.
Limitations of the current study include the relatively small sample sizes and the relative short follow up period with lack of long-term evaluation. More studies with larger scale and longer follow up period would be recommended.
In conclusion, although 3-snip punctoplasty is not the most effective procedure for treatment of acquired lower punctal stenosis grade 1 and 2, it remains of choice in certain circumstances, regarding the low cost of the procedure, and not requiring general anaesthesia which is a problem in old patients with possible un t general conditions. Thus, proposing that placing three interrupted sutures at the posterior ampulla after 3-snip punctoplasty may enhance the effect of the procedure would be of a great value.

Declarations
Con ict of interest The authors declare that they have no con ict of interest. Funding