A Protocol for Managing Watery Eyes in Patients with Punctal Stenosis

Introduction

Watery eye is a common problem that presents to a general ophthalmologist. It is not an age-specific condition and can affect people of every age group (newborn to the elderly). To manage it correctly, one must understand the exact pathogenesis and the involved factors. Normally, a balance exists between the production of tears in an eye and their exit/disposal by the lacrimal drainage system. This balance is disturbed in a patient with a watery eye, and restoring it is the key to proper management.

If tears are produced in excess it is called lacrimation. The over-production of tears exceeds the draining capacity of the lacrimal drainage system. Despite a normal-sized punctum and patent lower lacrimal drainage system, such a patient develops a watery eye. The causes of lacrimation are numerous and are related to an irritated/ inflamed ocular surface caused by infection (conjunctivitis, keratitis, corneal ulcer), ocular allergy, foreign body, misdirected eyelashes, and reflex tearing caused by superficial punctate keratitis in dry eyes. Eyelid infection/inflammation (blepharitis, meibomitis, or meibomian gland dysfunction) spreads to the adjacent ocular surface, produces tear-film disruption/ deficiency, and reflex tear production. In addition, topical medications have been known to cause ocular surface inflammation, especially the Anti-Glaucoma drugs.

On the other hand, a watery eye due to a problem in the lacrimal drainage system is called epiphora. To find out its exact cause, one must start an examination of the eyelids at the lateral canthal angle, where the ducts of the lacrimal and accessory lacrimal glands open. This is the most important part of clinical assessment for epiphora that is generally missed by ophthalmologists. If the lacrimal fluid is not transferred to the lacrimal lake, it will gather at the lateral canthal angle and overflow onto the cheeks.

For proper functioning of the lacrimal drainage system, the lateral canthal angle must be 1 mm higher than the medial canthal angle. The lower lid margin must be sharp and opposed to the globe. This allows the tear meniscus, normally 0.2 mm thickness, to form along the lower lid margin, extending from the lateral to the medial canthal angle. The fluid from the tear meniscus is picked up by the upper lid margin as it closes down over the lower lid margin at the end of each blink and spreads it over the cornea as the pre-corneal tear-film. The remaining fluid from the tear meniscus gathers into the depth of the medial canthal angle to form a lake, called the lacus lacrimalis or the lacrimal lake. The upper and lower punctae don’t lie opposed to each other; the upper is 3 mm medial to the lower punctum, and both are located within an elevated structure called the lacrimal papilla. Histologically, each punctum is 0.3 mm in diameter and is surrounded by a fibrous ring that forms the papilla [1]. The Riolan muscle (a narrow strip of the pre-tarsal orbicularis along the lid margin) and the dense fibrous tissue of the medial eyelid margin insert into the lacrimal punctum and pull it medially and posteriorly to open into the tear lake [2]. With each blink, the lacrimal fluid is sucked inwards through the punctae, into the cannaliculi, and then into the lacrimal sac by the contraction of the Horner’s muscle (the deep head of pre-tarsal orbicularis muscle) and is referred to as the “Lacrimal Pump” [3, 4]. Once the fluid builds up into the lacrimal sac, it is pushed downwards by gravity into the nasolacrimal duct which opens in the middle meatus of the lateral nasal wall. Investigation of epiphora, therefore, starts at the lateral canthal angle and ends by examining the nasal cavity. Any condition that alters the anatomical integrity of any of these structures can cause epiphora.

The true incidence of epiphora due to punctal stenosis or occlusion has not been determined in any large population- based studies. In a retrospective study in Canada [5], 8% of patients had epiphora either due to punctal stenosis or canalicular blocks. In a prospective study, 54.3% of the patients were diagnosed with punctal stenosis [6]. Punctal occlusion or agenesis can either occur congenitally due to embryological maldevelopment or can be acquired later in life.

The etiopathogenesis of acquired punctal stenosis is attributed to a common mechanism of chronic, recurrent inflammation [7]. This results in enhanced sub- mucosal fibrosis and constriction of the punctum, or the formation of a tight narrow slit. In addition, the Riolan muscle hypertrophies, surrounds the punctum and the vertical canaliculus, constricts the punctal opening by its continued spasm, and results in a pinpoint punctum. [8]. An inflammatory membrane may form over the narrowed punctum thus occluding it [9].

Therefore, ocular surface inflammation results in a watery eye in which the elements of lacrimation as well as epiphora co-exist (punctal stenosis ± blocked cannaliculi or the nasolacrimal duct). In addition, most of these patients are more than 50 years old. The involutional change in the structure and function of eyelids further adds to the problem. The loss of muscle tone, loss of elastin, and increased deposition of collagen in the subcutaneous tissue result in sagging of the lower lid and increased horizontal lid laxity [10]. This interferes with the function of the lacrimal pump mechanism with reduced transfer of tears to the lacrimal drainage system. Excess collagen deposition under the punctal mucosa and loss of elastin makes the punctal opening a tight narrow slit, while lid laxity causes punctal eversion resulting in epiphora. Another important factor resulting in a watery eye in the elderly population is the increased prevalence of dry eyes and reflex tearing/lacrimation [11, 12]. The prevalence of severe MGD and meibomian gland loss also increases with age [13, 14]. Therefore, identifying all factors that are causing lacrimation as well as epiphora and treating them is the key to proper patient management.

Though the reported rates of acquired punctal stenosis vary between 8-54.3%, it is a relatively simpler problem to treat surgically than the obstruction in the distal lacrimal drainage system. Even then, there is a whole armamentarium of surgical procedures to treat it i.e. 1 snip to 4 snip punctoplasty, laser punctoplasty, punctum pucker procedure, punctum wall removal with Kelly’s or Reiss punch, and electrocautery. Recurrent stenosis/occlusion is a common complication and to prevent that, adjunctive measures like stents are used to keep the punctal opening patent. These maybe perforated or fenestrated punctal plugs, mini-Monoka, or self-retaining bicanalicular stents. Despite all these measures, the surgical procedures have a variable success rates as most ophthalmic surgeons focus only on the stenosed, occluded punctum. The problem of a watery eye persists in many cases as all the causative factors are neither identified nor treated.

There are no uniform acceptable guidelines to manage the simple and common problem of punctal stenosis. In this study, we chose the rectangular 3-snip punctoplasty without using any stents. The aim of this study was to propose a protocol/suggest guidelines to maximise surgical success and achieve 100% patient satisfaction. To the best of our knowledge, no one has tried doing that before in the scientific literature.

Methodology

A prospective, interventional study was carried out at a tertiary care oculoplastics centre for a period of 7 years, from March 2016 till April 2023. 44 consecutive patients (77 eyes/ cases) presenting with epiphora, ocular discomfort, and misty vision were included in the study. All aspects of this research protocol adhered to the tenets of the Declaration of Helsinki.

A detailed history was taken regarding visual fluctuation during visual tasks such as reading, driving, watching television, or staring at a computer/smartphone screen. Symptoms of ocular or eye lid discomfort, pain, redness, and irritation were noted in the clinical notes. The severity of their watery eye was inquired and graded according to the Munk score. A history was taken regarding previous ocular surgery, contact lens wear, topical antiglaucoma medications (prostaglandin analogs, beta blockers, carbonic anhydrase inhibitors), chemotherapy, irradiation, a fatty diet intake, and any systemic disease (rheumatoid arthritis, Sjögren’s syndrome and systemic lupus erythematosus).

All cases had a complete ophthalmological assessment. The state of upper and lower lid margins (thickening, telangiectasia, foaming or frothing at the angles of the eyes, and crusting or keratinisation) was noted. Eyelashes were assessed regarding mis-direction, distichiasis, or the presence of scales at their bases. The meibomian duct orifices were examined and plugging by thick secretion, notching, and the type of meibum squeezed from them was noted. A co-existing Meibomian gland dysfunction (MGD) was graded accordingly.

The tear meniscus height (TMH) was measured, below the centre of the pupil along the lower lid margin, by using 1 mm slit lamp beam. The distance between the visible junction of the cornea with the tear meniscus and the upper edge of the lower eyelid was defined as the lower TMH. Normal TMH was taken as 0.2 mm.

Surgical Procedure

The goal of the treatment of punctal stenosis was to achieve a functioning lacrimal punctum, with an adequate size and a correct position pointing inwards into the tear lake. The surgery was performed by a single surgeon under local anaesthesia. 1.5 ml of a 2% lignocaine with 1: 1, 00,000 adrenaline was injected subcutaneously into the medial lid margin below the punctum. The stenosed punctal opening and the lumen of the inferior as well as the common cannaliculi was maximally dilated by the Bowman’s puntum dilator. Cases in which a membrane was occluding the punctum, or no punctal opening was visible, it was perforated at the centre of the ampulla by either the sharp tip of the punctum dilator or the tip of a no 11 Bard Parker blade, and maximally dilated. Next, the 3-snip punctoplasty was performed in a rectangular shape. The posterior wall of the dilated punctum was grasped with a fine tooth- forceps. The blades of a curved Vanass scissors were introduced vertically downwards and outwards along the medial wall of the punctum and the adjacent part of the vertical canaliculus and incised for 2 mm. Similarly, the lateral wall was incised for 2 mm. The cut segment of the posterior punctal wall (facing the lacrimal lake/eyeball) was held taut with the tooth forceps and the intervening tissue was incised horizontally. A rectangular shaped segment of the posterior wall of the punctum and the vertical canaliculus was excised.

To ensure punctal/canalicular patency and to wash any debris, syringing was performed through the enlarged punctal opening. Bleeding was stopped by a cotton swab soaked in 1:100,000 adrenaline solution. Care was taken not to use any cautery to avoid scarring. Cases with bilateral punctual occlusion/stenosis had a simultaneous bilateral surgery. The cases with an everted punctum, also had a diamond tarso- conjuncival excision simultaneously. An antibiotic ointment was instilled into the eye and a pressure dressing applied for 24 hours. The dressing was removed the next day in clinic. They were advised to apply antibiotic-steroid ointment twice daily into the medial canthus for 1 week. At each follow-up, the severity of epiphora and the state of newly formed punctal opening was assessed. All cases had punctal dilation in the clinic whilst sitting on the slit-lamp under topical anaesthesia. This was done weekly for one month and then every 2 months for the next 6 months. Success was defined objectively by the resolution of epiphora and noted subjectively by the clearance of the dye from conjunctival cul de sac on fluorescein dye disappearance test.

Statistical analysis was performed using SPSS version 16. Paired t-test was used to detect the difference between pre- and postoperative data. A p value of < 0.05 was considered significant.

Complications Following Punctoplasty

Punctal constriction was noted during the early follow- up period in all cases which was managed by maximal dilation at each visit. Fine membranous occlusion was noted in 2 cases with blepharitis who had stopped topical medication early. Frothing at the angles of the eye and at the lid margins was noted in 17 cases post-operatively for which the therapy for MGD was continued for the next 2-4 months.

Discussion

A correlation between age and the type of punctal stenosis has been suggested in various studies [11, 13]. Our patients were on an average 61 years old. A definite female preponderance (63.3%) was noted in our cases similar to other studies. This has been proposed to be related to post-menopausal hormonal changes resulting in dry eyes, MGD, keratinised epithelium, and increased ocular surface inflammation [14].

Amongst our cases, pinpoint punctae were predominantly noted in relatively younger patients (between 41-60 years of age) with severe eyelid inflammation due to blepharitis and MGD. 21 of these cases also had spastic entropion of the lower lid which improved on its own as the eyelid inflammation subsided with topical therapy. Slit-like and membranous punctal occlusion was common in the elderly patients (more than 60 years old). This correlation has been made in other studies too [7, 8, 15].

In this study, we treated the cause of lacrimation in all our cases meticulously, pre-operatively, for 1-3 months. Once the ocular surface and lid margin inflammation was under control, As evident subjectively by improved symptoms of ocular irritation and objectively, only then punctoplasty was performed. Meibomian gland dysfunction, posterior blepharitis, and allergic conjunctivitis are recurrent conditions. They disrupt the pre corneal tearfilm, cause dryness of the cornea/conjunctiva (evident by Fluorescein staining), and reflex watering/lacrimation. In addition, the eyelid inflammation spreads to the punctum [16] and results in its re-stenosis/occlusion by Riolan muscle hypertrophy ± enhanced fibrosis in its submucosa, months or years later.

Therefore the treatment of OSD was continued post- operatively for 2-4 months. The patients were educated regarding the recurrent nature of the disease. Ensuring a meticulous control of ocular surface inflammation pre- and post-operatively was an important reason for achieving surgical success of 97.4% and a 100% patient satisfaction in our study. We refrained from using antibiotic-steroid combination ointment or eyedrops containing prednisolone acetate, dexamethasone, and moxifloxacin as they have been implicated in causing conjunctival fibrosis and worsening/ recurrent punctual stenosis [17, 18].

We chose the rectangular 3-snip punctoplasty as this is believed to maintain the normal anatomy and physiology of the canalicular system. It does not disturb the lacrimal pump mechanism [19, 20]. In a study by Ali et al., complete resolution of symptoms was achieved in 82% cases following the horizontal 3-snip punctopasty; 10.3% of their cases had functional epiphora and 5.3% had restenosis. Even after placing perforated punctal plugs, they had a success rate of 85% [21]. Singh, et.al. also had similar results with anatomical success rate of 84% with restenosis in 16% cases at 6-month follow up [22]. Wong, et al. used Kelly’s punch instead of 3-snip punctoplasty and achieved 92% functional success rate [23]. However, the vertical and the proximal segment of horizontal canaliculi were excised during punching which has been proposed to interfere with the lacrimal pump mechanism. The physiological role of the punctum to maintain positive pressure on lid closure during a blink and negative pressure within the horizontal canaliculus on lid opening at the end of a blink is lost [24].

The second important reason for achieving a surgical success of 97.4% in our study was the repeated punctal dilation post-operatively for 6 months. This was considered necessary in view of the underlying histological changes due to chronic inflammation, and is the main reason for punctual restenosis in the above mentioned studies. Following punctoplasty, the cut segment of the punctum and adjacent vertical canaliculus heal by scar tissue formation. As the scar tissue contracts, punctal opening narrows irrespective of the type of punctal stenosis. Secondly, in pinpoint punctae, as the cut Riolan muscle heals by scar tissue, it further constricts the punctal opening. A third factor is flaring up of the underlying eyelid inflammatory disease (MGD, posterior blepharitis) post-operatively that results in recurrent membrane formation over the punctum following punctoplasty. These changes were evident in all our cases in the first 4-6 weeks post-operatively as demonstrated by the gradual improvement in the Munk score and Kashkouli grade (Table 4). Therefore, repeated punctal dilation at each follow-up visit was necessary to break the inflammatory adhesions and stretch/relax the scar tissue as well as the encircling Riolan muscle.

This protocol was repeated at each follow-up visit for 6 months. By that time, the healing process had completed and the punctal opening remained patent without using any stents. In our study, 55 cases (71.4%) had additional lower eyelid deformities that contributed to epiphora in addition to punctal stenosis. The corrective surgery was performed simultaneously to the 3-snip punctoplasty. The correction of all contributory factors added to our surgical success and patient satisfaction.

The strengths of our study are its prospective nature, a detailed pre-operative clinical assessment of patients presenting with watery eyes, including cases with severe epiphora of long duration, 75% cases had previously failed punctplasty, a uniform surgical technique performed by a single surgeon, a careful assessment of the surgical outcome, and suggesting a guideline/protocol for managing such patients.

Possible Biases/Limitations of our Study

Perhaps not a large number of cases, a short follow-up, and conducted at a single centre.

Conclusion

A disturbed balance exists between tear production and their drainage in all cases presenting with watery eyes. Age-related involutional changes and OSD are the common underlying factors. A protocol is suggested to restore that balance, especially in patients with a simple but common problem like punctal stenosis, thus achieving a 100% patient satisfaction.

• A thorough clinical assessment to identify all factors causing lacrimation and treating them prior to performing lacrimal drainage surgery i.e. punctoplasty.
• Ocular surface diseases are chronic and recurrent in nature. Steroid-sparing topical anti-inflammatory therapy must be used to prevent steroid-related complications.
• Identifying lower lid margin pathology that may also be contributing to epiphora besides punctal stenosis or obstruction in the lower lacrimal drainage system.
• Repeated punctal dilatation post-operatively at each follow-up visit and continued topical anti-inflammatory therapy is necessary to avoid recurrent punctal occlusion. Patient education regarding recurrent nature of ocular surface diseases. They should seek treatment early to prevent re-stenosis of the punctum.