Lacrimal Drainage Surgery in a Patient with Dry Eyes

during the blink cycle. Secondly, the removal of ocular surface debris that is achieved by the continuous flow of tears from lateral to medial across the ocular surface, by the dilution of the tear lake with new secretion, and by removal of debris through tear drainage.

Failure of lacrimal drainage will prevent this physiological cleansing of the ocular surface and thereby lead to an accumulation of noxious substances within the tear film; this failure of clearance being exacerbated by concentration of retained surface debris by evaporation from the stagnant tear lake. The noxious substances may be extrinsic or intrinsic: Extrinsic factors include external allergens (such as pollens or dust mites) and external physical or chemical irritants, such as irritant fumes or dusts. Intrinsic factors include the antigens from commensal bacteria (especially staphylococci) on the lid margins or in meibomian secretions, and the inflammatory mediators that spill onto the ocular surface from the chronically inflamed conjunctiva of the dry eye. The inflammatory load on the ocular surface is particularly great in a dry eye without tear drainage – not only because of their lack of removal and their concentration by tear-film evaporation, but also because the poor environment is easily exploited by periocular commensal bacteria which, in turn, proliferate and markedly exacerbate the already significant chronic conjunctivitis [1–3]. A much more severe inflammatory and infective load – often with unusual bacterial flora – can arise where nasolacrimal duct occlusion is present, with transcanalicular wash-back of debris from the lacrimal sac into the tear film (a so-called ‘volume’ sign [4]). Although canalicular occlusion alone will stop wash-back of this infective and inflammatory debris, such occlusion risks a severe dacryocystitis unless occlusion is preceded by dacryocystectomy or dacryocystorhinostomy (DCR).

Rational Management of the Lacrimal Drainage

System in Dry-Eyed Patients

Where occlusion of the lacrimal drainage puncta or canaliculi occurs as part of the underlying disease causing dry eye (for example, with mucous membrane pemphigoid or after Stevens-Johnson syndrome; fig. 1), lacrimal surgery is required only rarely. However, despite intensive treatment with preservativefree anti-inflammatory and antibacterial drops, some of these patients develop such a severe toxic response that the ocular surface is improved only by establishing free drainage of the inflammatory mediators. This type of patient typically requires external DCR with retrograde canaliculostomy [5] or with primary or secondary placement of a glass Jones’ canalicular bypass tube [6].

Where the patient with a dry eye and patent tear drainage pathways needs preservation of ocular surface fluids, consideration should be given to canalicular

Fig. 1. Occlusion of upper and lower (arrow) lacrimal drainage puncta due to cicatricial conjunctival disease arising from chronic topical ocular medication. Squamous metaplasia and the loss of plica semilunaris and caruncular structure are readily evident.

occlusion. Whilst there are many commercially available plastic plugs for occluding either the puncta or canaliculi, the foreign surface of such devices inevitably gathers a gross biofilm (particularly in the already disadvantaged ocular environment of the dry eye) that can only exacerbate the toxic changes on the diseased ocular surface. If such patients require occlusion of outflow, this should first be tested by a reversible occlusion of both the upper and lower canaliculi – with punctal plugs or self-dissolving (collagen) canalicular plugs – to check that the ocular surface disease is not worsened by the loss of tear-film outflow: where all is well, canalicular occlusion by thermal cautery will succeed in almost all patients, but excision of the canalicular ampulla may be needed where this fails.

To reduce ‘wash-back’ of toxic debris from the lacrimal sac into the tear lake, patients with nasolacrimal duct occlusion should all undergo DCR; the absolute cure of wash-back being – in practical terms – achievable with external DCR and anterior ethmoidectomy [4]. Although dacryocystectomy would also eliminate wash-back, with the apparent benefit of occluding outflow, a complete absence of fluid drainage from the ocular surface might – as already discussed above – actually worsen the dry eye. Rather than primary dacryocystectomy, it is best to perform external DCR with later canalicular occlusion.

Surgical Techniques

External Dacryocystorhinostomy

DCR is designed to widely open the lacrimal sac into the nasal space, thereby eliminating the lacrimal sac and opening the common canaliculus directly into

the nose [4] and the wide soft-tissue anastomosis required is possible only with an external approach incorporating a limited anterior ethmoidectomy.

The procedure can be performed under either general or local anaesthesia, typically as a day-case procedure [7]: Local anaesthesia with intravenous sedation tends to provide an excellent operative field, although it can be associated with rather more postoperative nasal oozing than that after general anaesthesia. Local anaesthesia is readily achieved by spraying the anterior nasal cavity with lidocaine 4% spray and infiltrating the medial one-third of the lower eyelid and paranasal area with a solution of 0.5% bupivacaine with 1:100,000 to 1:200,000 epinephrine. Anterior ethmoidal nerve block, using 2–3 ml of the same solution, is achieved by passing a 23-gauge needle along the medial orbital wall from just above the medial canthus and angulated about 20 below the axial plane (to avoid injury to the anterior ethmoidal vessels). The anterosuperior nasal cavity is packed with about 80–100 cm of 1-cm packing gauze soaked in 2 ml of cocaine solution (4 or 10%) and the packing left in place until the silicone intubation is passed through the nasal cavity. Topical ocular anaesthesia, such as 0.5% amethocaine, is also required during the surgical procedure. Maximum vasoconstriction is obtained if the local anaesthetic is given at least 10 min before surgery commences and is most conveniently given prior to surgical gowning.

Where general anaesthesia is the preferred choice of the patient or surgeon, controlled hypotensive anaesthesia suitable for day-case admissions is readily achieved with modern techniques – such as either total intravenous anaesthesia (TIVA) using Propofol and Remifentanyl, or the combination of a volatile inhalation anaesthetic (such as isofluorane) with titrated small doses of a -blocker to prevent the compensatory tachycardia. For patients under general anaesthesia, nasal vasoconstriction is readily achieved, after sterile preparation and draping, by placing 3 cotton-tips – moistened in 1:1,000 epinephrine – as far superiorly and anteriorly as possible within the nasal space. Whether under local or general anaesthesia, the head-end of the operating table should always be raised during surgery, to decrease the cephalic venous pressure.

A 12to 15-mm straight skin incision should be placed on the flat paranasal area, starting just above and about 1 cm in front of the medial canthal tendon – this type of incision only rarely leaving a noticeable scar, whereas more posterior incisions tend to ‘bowstring’ across the inner canthal concavity. The skin is then undermined posteriorly to the anterior limb of the medial canthal tendon, leaving the orbicularis muscle and angular vessels undisturbed. The pretarsal and preseptal orbicularis fibres are separated by blunt dissection along the line of the fibres, this revealing the anterior lacrimal crest along which the paranasal periosteum is widely divided using a Rollet’s rougine; damage to the vascular preseptal orbicularis muscle and the angular vessels may be avoided by

Fig. 2. Landmarks for osteotomy on skull (a) and on clinical transillumination (b), indicating a size that allows suture of adequate mucosal anastomoses and, thereby, ensuring an absolute cure of ‘volume’ symptoms and signs of lacrimal disease.

retracting them medially with a squint hook, or (where under general anaesthesia) by placement of 2/0 silk traction sutures through the anterior periosteal edge, encircling the angular vessels and orbicularis, with the sutures clipped under tension to the surgical drapes. The rougine is used to displace the lacrimal sac from its fossa and the maxillolacrimal suture line entered using an angled (e.g. Traquaire’s) periosteal elevator, this being worked up and down along the bony suture; should the bone be too thick to breach, at this point, it is possible to enter the ethmoid sinus through the lamina papyracea (behind the posterior lacrimal crest), or the bone of the anterior lacrimal crest may be thinned down using a burr, or hammer and chisel.

A large rhinostomy (fig. 2) is fashioned by first crossing the anterior lacrimal crest as far superiorly as possible (where the crest is thinnest), and the directing bone removal inferiorly and in front of the crest (to give an ‘L-shaped’ rhinostomy). Every few bites, the periosteal elevator should be swept around the bone edge to separate the underlying nasal mucosa from the bone and, where cotton-tips have been placed within the nose, these should be withdrawn sufficiently to allow the rhinostomy to be fashioned. The remaining spur of thick bone of the frontal process of the maxilla is then removed and the thin bone between the upper duct and nose is removed using a Jensen bone nibbler. Further bone should be removed up to the skull base, to ensure there is none alongside the common canalicular opening, and posteriorly to include a partial ethmoidectomy – removal of the bone fragments and mucosa facilitating the sutured anastomosis of posterior mucosal flaps.

A ‘00’ lacrimal probe is passed, through the lower canaliculus, into the lacrimal sac to tent its medial wall and a No. 11 blade used to enter the lumen of

the lacrimal system at the anteromedial face of the sac-duct junction (thereby avoiding damage to the internal opening of the common canaliculus). Once the lumen has been identified, the medial wall of the sac and upper duct are opened completely with Westcott spring scissors; occasionally it will be found that only the relatively thick lacrimal sac fascia has been opened, and the thin sac mucosa remains intact. Where there is a membranous block of the internal opening of the common canaliculus, this should be carefully excised using a No. 11 blade or fine scissors. With the nasal packing or cotton-tips in place to avoid damaging the septal mucosa, the nasal mucosa is incised vertically with a No. 11 blade to create anterior and posterior flaps; this incision should be about 3–4 mm in front of the ‘arch’ formed by the anterior end of the middle turbinate attachment – this ‘arch’ generally being evident after partial ethmoidectomy. Relieving horizontal incisions are made at the superior and inferior bone edges to mobilise both flaps.

The anterior flap is held away from the operative field by passing a 6/0 absorbable suture (on an 8-mm diameter half-circle needle) through the middle of preseptal orbicularis fibres – that is, those that have been retracted medially by the assistant – and then through the middle of the anterior nasal flap, the two ends clipped (with the needle still attached) and hung aside across the nasal bridge. The posterior flaps are sutured – from the fundus of the sac to the entrance to the duct – with a 6/0 absorbable suture placed in a locked continuous suture; to facilitate this suturing in a recess, it is best to use the whole needle length, with it reverse-mounted in a non-locking angled needle holder. The lacrimal probe, kept in place during suture of the posterior flaps, is removed and silicone intubation placed. The preplaced anterior suture is passed through the anterior sac flap, opposite the internal opening – this effectively ‘suspending’ the mucosal anastomosis from the orbicularis fibres. Two other suspended anterior sutures are passed: the upper one is passed through preseptal orbicularis above the first suture, then through the upper end of the anterior nasal flap, through the upper anterior sac mucosa and finally through the stump of medial canthal tendon; the lower suture is passed through orbicularis, through the lower end of the anterior nasal mucosa, through the anterior sac flap near the nasolacrimal duct, and finally through the subdermal tissues lateral to the lower part of the skin incision. Skin closure is achieved with a 6/0 nylon continuous mattress suture and a firm dressing applied to the operative site for 12 h.

With a sutured primary mucosal anastomosis, nasal packing is not required routinely although ribbon gauze, moistened with 1:1,000 epinephrine, may be placed if major primary haemorrhage occurs and this pack left undisturbed for 5 days. The patient should be nursed semi-erect on bed rest after surgery, to reduce nasal venous congestion and oozing, and hot drinks avoided for 12–24 h. A topical combined antibiotic and anti-inflammatory medication is prescribed for a few weeks and, unless systemic antibiotics have been given during surgery, a short

Fig. 3. Retrograde canaliculostomy during DCR. a Endonasal view of a ‘1’ gauge probe, bent to about 70 , inserted retrogradely into the internal opening of the common canaliculus until it meets the point of canalicular obstruction. b The eyelid margin is gripped near the probe tip and a marginal incision made into the most lateral point in the canaliculus, prior to silicone intubation.

course of oral antibiotics is recommended to reduce postoperative infection. The dressing is removed on the day after surgery and nose blowing discouraged for the first week, to reduce the risk of epistaxis or subcutaneous emphysema. Skin sutures are removed at about 1 week and the intubation at about 4 weeks after surgery, by which time epithelialisation of the surgical fistula has been completed.

Dacryocystorhinostomy with Retrograde Canaliculostomy

Retrograde canaliculostomy is designed to open – at the lid margin next to the medial tear lake – canaliculi that are blocked within their first 7 mm or so, but have a patent common canaliculus [5]. As the extent of canalicular block can only be established at the time of surgery, the patient should be warned that they might require primary or secondary placement of a Jones’ canalicular bypass tube.

External DCR (see above) is completed to the stage of having sutured the posterior mucosal anastomosis and the internal common canalicular opening is entered retrogradely using a ‘0’ gauge lacrimal probe, bent perpendicularly on itself at about 8–9 mm from the end. The probe is passed as far laterally as possible along each canaliculus (if possible), a 1–2 mm cut-down made to expose the probe on the lid margin (fig. 3), the ‘pseudo-puncta’ intubated and the DCR completed in a standard fashion. If solely the common canaliculus is available, its lateral end should be opened into a carunculectomy site and – in this and other such cases where only a single canaliculus is available – the returning end of the silicone intubation passed through one of the punctal annuli and forced

medially through the lid tissues; this manoeuvre returning the intubation to the nasal space at a site remote from the common canalicular opening. Monocanalicular stenting is unlikely to stay in place because of the absence of a normal annulus at the ‘pseudo-punctum’.

The intubation can be removed when the conjunctival and canalicular epithelium have united – typically within 2–3 weeks – and they should not be left for much longer or ‘cheese wiring’ will cause a cross union between the lids. Closed placement of a canalicular bypass tube is required if the pseudopuncta fail to control symptoms.

Closed Placement of Jones’ Canalicular Bypass Tubes

The canalicular bypass tube (most commonly a Lester Jones’ Pyrex tube), is designed to allow free tear flow from the medial tear lake into the nose, by way of a false conduit. Closed placement is indicated where watering continues after canaliculo-DCR, after retrograde canaliculostomy or, exceptionally, after a functioning standard DCR (for example, in patients with facial nerve palsy). Although requiring continued maintenance and associated with various longterm problems, the majority of people with these drainage devices consider them to be of benefit [6].

The nasal end of a bypass tube needs to be free within the nasal space, somewhat in front of the middle turbinate, and intranasal examination is required – best with rigid endoscopy, although a good headlight and nasal speculum are often adequate. As nasal local anaesthesia (with vasoconstriction) creates an inappropriately capacious nasal space, optimum positioning of the tube is achieved under general anaesthesia – when the nasal cavity is closest to normality.

The ocular end of the tube should be positioned hard behind the medial end of the lower limb of the canthal tendon (fig. 4): this is best accomplished by using a Nettleship dilator to pierce the epithelium at the desired position and a track then forced through to the nose using the smallest end of the double-ended (‘bullhorn’) dilators supplied with the commercial sets; this track should typically run about 30 downhill and in, or slightly forward from, the coronal plane. The position of entry into the nasal space is checked for suitability, an appropriate tube (commonly 11 mm, with a 3.5-mm flange) slipped onto a ‘1’ gauge lacrimal probe that is passed along the dilated track, and the tube forced along the track and into the nose using the end of the thumbnails (fig. 5); the use of any form of instrument on the tube flange tends to shatter it, and this should be avoided at all costs. The position of the ocular and nasal ends of the tube should be checked after withdrawing the ‘1’ probe, and spontaneous flow of saline from the ocular surface verified. Suture of the tube is unnecessary after secondary placement.

Fig. 4. Jones’ canalicular bypass tube positioned at the left inner canthus, just behind the lower lid margin – the lumen of the tube being directed about 30 downwards into the nasal space.

Fig. 5. Secondary insertion of a Jones’ tube: After dilating a downwardly directed track from the inner canthus to the nose, the bypass tube – slipped onto a ‘1’ gauge lacrimal probe (a) that is passed along the track (b) – is forced into the tissues (c). The glass flange tends to shatter if instruments are used to drive the tube, and placement should be undertaken using the ends of the thumb-nails (d).

Dacryocystectomy

Dacryocystectomy is probably indicated only in patients with wellcontrolled ocular surface disease in the presence of longstanding canalicular occlusion, in whom there has been an episode of acute dacryocystitis or increasing dilation of the sac due to mucus secretion.

Using the same approach as external DCR, the anterior limb of the medial canthal tendon is detached from the nasal bone and peeled laterally from the underlying tissue before the sac is mobilised from its fossa. Once peeled about 1 cm laterally, the underlying common canaliculus is transected and the sac mobilised medially from the underlying orbital tissues by careful dissection medially across the posterior lacrimal fascia. The tightly bound fundus and medial face of the sac is separated from the lacrimal sac fossa, the isolated sac drawn upwards whilst the superior part of the nasolacrimal duct is freed from its canal, and the duct transected as low as possible. The remaining stump of nasolacrimal duct should be thoroughly cauterised to encourage fibrosis and, after haemostasis, the medial canthal tendon reattached to the neighbouring orbicularis oculi muscle and the skin incision closed.

Permanent Punctal Occlusion

Before performing permanent punctal occlusion, it is imperative to verify the benefit of occlusion by a temporary canalicular plugging: This may be achieved by insertion of collagen plugs, under topical anaesthesia, into the horizontal portion of the upper and lower canaliculi. If the patient develops watering or an exacerbation of ocular surface inflammation, the original diagnosis of ‘dry’ eye – and advisability of permanent occlusion – should be questioned. Likewise, it is unwise to occlude the canaliculi in the presence of a lacrimal sac mucocoele or pyocoele – conditions in which DCR should be first performed. Techniques for punctal and canalicular occlusion are presented in another chapter.

References

1Van Bijsterveld OP, Klaassen-Broekema N: Lacrimal conjunctivitis. Bull Soc Belge Ophthalmol 1990;238:61–70.

2Rapoza PA, Quinn TC, Terry AC, Gottsch JD, Kiessling LA, Taylor HR: A systematic approach to the diagnosis and treatment of chronic conjunctivitis. Am J Ophthalmol 1990;109:138–142.

3Rose GE: The giant fornix syndrome. An unrecognised cause of chronic, relapsing, grossly purulent conjunctivitis. Ophthalmology 2004;111:1539–1545.

4Rose GE: The lacrimal paradox: towards a greater understanding of success in lacrimal surgery. Ophthal Plast Reconstr Surg 2004;20:262–265.

5Wearne MJ, Beigi B, Davis G, Rose GE: Retrograde intubation dacryocystorhinostomy for proximal and mid-canalicular obstruction. Ophthalmology 1999;106:2325–2328.

6Rose GE, Welham RAN: Jones’ lacrimal canalicular bypass tubes: 25 years’ experience. Eye 1991;5:13–19.

7Hanna IM, Powrie S, Rose GE: Management outcome for day-case open lacrimal surgery, as compared to inpatient management. Br J Ophthalmol 1998;82:392–396.

Geoffrey E. Rose

Lacrimal and Orbital Clinics, Moorfields Eye Hospital City Road, London EC1V 2PD (UK)

Tel. 20 7566 2034, Fax 20 7566 2019, E-Mail geoff.rose@moorfields.nhs.uk