Continuing education CET - Mark Allen

14 | Optician | 26.10.07 opticianonline.net

Continuing education CET

Punctal plugs and cauteryAndrew Matheson describes the indications for punctal plugging and cautery, and how to manage problems along the way. C7684, one CET point, suitable for optometrists and additional supply optometrists

Punctal occlusion is not normally the first thing I consider when a patient presents with dry eye, although the patient may be

keen to have this procedure performed on their first visit. Normally, before attempting to reduce tear drainage, there are other issues to address. It is impor-tant firstly to optimise each component of the tear film as much as possible. This may include, for example, use of hot compresses, omega-3 supplementation and lid cleaning to treat meibomian gland dysfunction, or antibacterial lid cleaners if a blepharitis/meibomitis element is present.1

Use of hypotonic, electrolyte-balanced, preservative-free artificial tears may be appropriate if there was significant lissamine green staining present, as this would imply goblet cell damage, and hence an abnormal mucous layer.2,3,4 A patient’s fluid intake may be too low, or caffeine intake too high. Simply modify-ing diet and lifestyle may improve matters immensely.

If after two to three months address-ing the above considerations, the patient still has signs of corneal damage or dryness symptoms and a low tear volume or has to instil eye-drops at an unacceptably high frequency, then I would discuss punctal occlusion.

A different scenario might be, for example, a high myope or keratoconic, who has slightly reduced aqueous secretion on reaching the menopause, which means that there is no longer an adequate depth of tears on which to float her contact lenses. In this case of aqueous-deficient marginal dry eye, the inability to wear contact lenses adequately might mean that punctal plugs might be considered so that safe contact lens wear can be maintained. As previously, other cases of dryness, especially lid margin disease, should be addressed.5,6,8

Having decided that punctal plugs are an option, some would perform a trial with collagen plugs first. These are small cylinders of usually bovine or porcine material which are easily inserted using curved forceps into the puncta.

Often this trial is counter-produc-tive, because these plugs usually have dissolved in four to seven days. This is not normally long enough to evaluate the effect of a therapeutic interven-tion. Many patients have been told that punctal plugs will not help them, simply because there was not a reduc-tion in signs or symptoms within four to seven days after insertion. Such temporary plugs do have a place when considering plugging both upper and lower ducts.

In my opinion, if corneal and conjunctival staining has been reduced as much as possible, if the meibomian secretions are showing improvement, and the patient still has signs and symptoms, then it is OK to proceed with punctal occlusion using semi-perma-nent silicone plugs that can easily be removed if it turns out that their use is inappropriate. Patients with large puncta that have good tear evacuation are most likely to benefit. As most of the

tear drainage is normally via the lower ducts, it is the lower puncta which are normally plugged first.

How is it done?There are five main ways of perma-nently occluding the lacrimal drainage system:● Conventional silicone plugs. These now come in many shapes and sizes. Choice is down to the individual practitioner. I like a plug to be fairly high modulus, have a small head and come in a variety of sizes and shapes. Having a small head improves patient comfort as there is less of the plug proud of the punctum to irritate the nasal bulbar conjunctiva● Herrick intra-canalicular plugs (Figure 1) are fitted further down the canaliculus (Figure 2). They are more comfortable initially, but because of the stagnant column of tear fluid between them and the punctal opening, are theoretically more prone to infection

Figure 1 Close-up of Herrick intra-canalicular plug

Figure 2 Herrick Plug being inserted into puncta on its stainless steel stylus

Figure 3 Smart Plug being inserted



● Smart Plug. A thin rod made from thermosensitive acrylic, is inserted into the punctum using tweezers in a similar manner to a collagen plug (Figure 3). Inside the punctum, the plug shrinks in length and expands in width, adjusting itself to fit the punctum● Oasis Form fit plug. Again a one size fits all plug, this time made of a hydro-gel material. Once inserted into the punctum, it hydrates over a 10-minute period. As it hydrates, it increases in size until it completely fills the vertical canalicular cavity to form a personalised fit. The Form Fit plug expands into a soft, pliable, gelatinous material when it contacts tear film (Figure 4). As you can see from the picture, sometimes it can expand to a size greater than required (Figure 5). If this occurs, the excess can be trimmed with surgical scissors or fine upcurved tweezers (Figures 6 and 7). I find these plugs are useful if it is necessary to plug a lax puncta, that will not retain a conventional plug. The Form Fit plug comes mounted on an applicator similar to that used to insert a conventional silicone plug.● Cautery. This is a much more perma-nent treatment. Even with significant anaesthesia this is painful for the patient. Although in the past many had problems with this technique, if performed cautiously in skilled hands, it can be very successful, especially where the punctal opening/canalicu-lus is too large or lax to be plugged by other means. It is better to err on the

side of under-treatment, than cause too much lid destruction and scar tissue. The patient and practitioner need to be sure that this procedure is needed and desired by the patient. Unambiguous consent forms need to be fully under-stood and signed. Due to the risk of the patient moving at the moment the probe (Figure 8) is heated up, it is often wise to get them to wear a thick bandage contact lens to provide some protection against corneal damage. If the puncta does not close adequately the first time, it can be retreated on a subsequent visit (Figures 9 and 10). Obviously, a clinician needs to be very certain that occlusion is necessary before this essentially irrevers-ible procedure takes place. Adequate training is essential.

SyringingAll plugs that are fitted deeper than the punctal opening are removed if neces-sary by syringing the plug through the lacrimal apparatus (Figure 11). It is, therefore, imperative that the canaliculi are irrigated prior to fitting to ensure this exit route is patent. This applies to collagen plugs, Herrick intracanal-icular plugs, Smart Plugs and Form Fit plugs. If the lacrimal apparatus cannot be irrigated, then there would be no mileage in fitting the plug in any case.

FittingPersonally, I prefer to fit conventional silicone plugs wherever possible. They are more involved to fit, requiring the punctum to be measured first for size

Figure 4 Oasis Form fit plug in situ Figure 5 Expanded plug Figure 6 Trimming the plug

Figure 7 After insertion and trimming, the plug is clear and barely visible

Figure 8 The cautery probe Figure 9 Punctum immediately after cautery

Figure 10 Punctum after two weeks following cautery Figure 11 Syringing



and elasticity. This gives us an idea of the ideal size and shape. Because the right size of plug is fitted tightly into the punctum we know that tear flow is being stopped (Figure 12). A plug that is fitted tightly at first will function for longer. Also, the plug can be removed simply, if required using curved forceps. Opinions will differ between professionals on the choice of ideal implant, and no one type is suitable for everyone.

Patients should be warned that the plug might irritate slightly in the first few days after insertion until they acquire a hydrophilic mucous coating. Advising them to turn their head rather than their eyes reduces the cornea plug contact while this occurs.

When sizing a punctum for conven-tional silicone plugs the correct size of stainless steel gauge is the one that will just squeeze past the punctal ring and also shows resistance as it is removed. If this is not felt, the punctum is probably not very elastic and may distend after fitting producing a loose fitting plug (Figure 12). If this is suspected the

gauge can be moved from side to side while in the punctum to see if it enlarges easily. If it does so, a larger, more aggres-sively shaped plug is probably required. The tightly fitted body of the correctly sized plug pulls the head of the plug down tightly rendering it flush against the punctal opening. Such a fitting is most comfortable for the patient.

Nowadays, silicone plugs come pre-mounted on an insertion device that doubles up as a punctal dilator. After gauging the size of plug required, it is usually necessary to dilate the puncta slightly so that the body of the plug can be squeezed in. For smaller size puncta a metal dilator instrument is usually required as the disposable one that comes with the plug is not usually fine enough.

When fitting a plug, good manual dexterity is required to ensure that adequate force is used to twist the plug into place (Figures 13a and 13b), ceasing pressure as soon as the plug body enters the puncta, so that the head of the plug does not pass through the opening too.

If this event does occur, it is impor-

tant to stay calm and not press the plug-release mechanism, as it is often possible to ‘winkle’ the head of the plug back out again. If the plug that has been inserted too deep and is a tight fit it is unlikely to cause a problem, especially if it remains just below the surface. If the plug has gone too deep because it was really significantly too small, it is more serious and should be removed to be on the safe side.

Follow upThere have been reports of various problems encountered by patients fitted with punctal plugs. Most of these have been related to intra-canalicular plug fitting and are either an inflam-matory reaction to the plug material, often resulting in a pyogenic granu-loma (Figure 14) requiring surgical intervention, or infection.7 Because there is a stagnant column of tear fluid between the intra-canalicular plug and the punctum, infections in this region are more common. The conventional surface-mounted plug does not have this problem. If the very unlikely occur-

Figure 12a Correctly fitted Eagle Vision silicone punctal plug Figure 12b Loose fitting punctal plug that is too small for the punctal opening

Figure 13b A plug that has been fitted deeper than the punctal openingFigure 13a Punctal plug insertion after sizing and dilation


rence of canaliculitis were to occur it can be simply removed with tweezers, rather than surgery as in the case of the intra-canalicular plug.

Conventional punctal plugs become loose over time as the punctum expands as it ages (Figure 15). A plug may then rise up and rub on the conjunctiva causing irritation. Tears may flow round a loose plug allowing dryness to return. Personal experience fitting Eagle Vision


plugs over the last 18 years suggests an average effective plug residency time of three years, before refitting is necessary. I refit the patient at no charge if a plug comes out within a year. One elderly lady successfully wore the same pair of Eagle plugs for nine years. I suspect this might be a record, as anything over five years is rare. By this time the plug may in addition to getting loose be getting very contaminated and unhygienic.

Some US clinicians advocate replacing them periodically for this reason. The advent of antibacterial lid cleaners helps greatly reduce the bacterial colonisation of the plug.

Upper plugs often become loose sooner, possibly due to either the effect of gravity or possibly a difference in tautness of the upper and lower puncta.

In instances where there is difficulty

Figure 15 Upper plug that has become loose over timeFigure 14 Pyogenic granuloma tissue found surrounding a surgically removed Herrick intra-canalicular plug

An ever increasing number of practices are relying on The Outside Clinic tosolve their patient requests for domiciliary eye tests.Under the Code of Ethics and Guidelines for Professional Conduct - Aug 06, itstates: “If an Optometrist does not offer a domiciliary service, information shouldbe available in practice as to how a patient, carer, General Medical Practitioner(GMP) or others may access such services provided by other optometrists.”

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occluding the upper puncta, the Form Fit hydrogel plug often saves the day. Some clinicians also use the Smart Plug in these cases.

One of the disadvantages of occluding the lacrimal drainage system completely is that histamine and other inflamma-tory chemicals no longer drain away and as the levels of these substances builds up, the eye can become increas-ingly inflamed.

For this reason, when there is a meibomitis or severe allergic compo-nent, I would be very cautious about fitting such patients, and only plug one puncta from each eye, normally leaving the upper puncta unoccluded.

ConclusionTo summarise, punctal occlusion is a safe and effective procedure. It is impor-tant to select patients carefully, treating other dry eye components first. Good visualisation and manual dexterity are essential for safe and accurate fitting. Irrigation must precede intracanal-icular fitting. The correct fitting of surface-mounted plugs is easily revers-ible. Punctal occlusion can really be of benefit to the aqueous deficient dry eye patient, and should be a service more widely available in an optomet-ric setting.

Further information about these procedures can be viewed on the recent DOCET training DVD, Dry Eye Management. ●

References1 Matheson AC, Dry Eye Management the Theratears Way, Optician, 01/09/2006.2 Matheson AC, Use of stains in dry eye assessment, Optician, 02/03/2007.3 Korb DR, The Tear Film: Its role today and in the future, p126-190, BCLA pubs Butterworth Heinamann 2002.4 Gilbard J & Keynon K, Tear diluents in the treatment of keratitis sicca, Ophthalmology, 1985; 92, 613-626 5 Morier A, Plug. For the right patient its great, Rev Optom, April 1999.6 Hom M, Don’t plug. Find the true cause,

● The Ocular Solutions Lacrimal Apparatus Wall Chart is available at no charge for a limited period to interested clini-cians. Details can be found on the Ocular Solutions www.ocularsolutions.com. Email: [email protected]

● Andrew Matheson is a therapeutic optometrist practising in Alresford, Hampshire. He is a director of Ocular Solutions, supplying dry eye and clinical products to the profession

Multiple-choice questions – take part at opticianonline.net

1 Which of the following statements about collagen plugs is false?

A They are usually of animal originB They usually take aroung 15 to 20 days to

dissolveC They are inserted into the puncta using

curved forcepsD They have a place when plugging upper and

lower puncta

2 Which of the following statements about the Herrick intra-canalicular plugs is true?

A They cause more initial discomfort than other designs

B They are less prone to infectionC They tend to stand proud of the punctal

openingD A stagnant column of tears is found over the

plug

3 Which of the following is false regarding the Smart Plug?

A They are inserted in a similar manner to collagen plugs

B They lengthen within the canalC They expand to the width of the canalD They are made from thermosensitive acrylic

4 Which of the following statements about the Oasis Form fit plug is false?

A It can expand beyond the size requiredB They are often useful to fit very lax punctaC It hydrates over a 10-minute intervalD It is inserted in a similar manner to collagen

plugs

5 Which of the following statements about cautery is false?

A It is a painless procedure when anaesthesia is employed

B It is useful for wide or lax punctal openingsC The invasive nature of the procedure makes

re-treatment impossibleD A thick bandage lens may help protect the

eye during treatment

6 Which of the following might contraindicate punctal plugging?

A MeibomianitisB Sjögren’s syndromeC MenopauseD Rheumatoid arthritis

To take part in this module go to opticianonline.net and click on the Continuing Education section. Successful participation in each module of this series counts as one credit towards the GOC CET scheme administered by Vantage and one towards the Association of Optometrists Ireland’s scheme. The deadline for responses is November 22

Rev Optom, April 1999.7 Haun-Chen Hsu, Ampullary Pyogenic Granuloma as a complication of Lacrimal Plug Migration, Chang Gung Med Journ, June 2002.8 Steele C & Sideropoulou A, How does therapeutics fit into contact lens practice?, Optician, September 2007.9 Geisse L, Management of complications after insertion of the Smart Plug punctal plug: A study of 28 patients, Opthalmology, Oct, 2006.

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Continuing education CET - Mark Allen