Medial ectropion

Loss of lid margin apposition to the globe and resulting weakness of the physiological pump of blinking can lead to tear overflow. The repeated need to wipe aggravates the lid laxity. All patients with ectropion can present with epiphora, but this is more usual in those with mainly medial ectropion. The nasolacrimal outflow system should be syringed to elucidate any obstruction, as surgical correction of the ectropion alone will clearly not rid the patient of the symptoms in the presence of an obstruction; it will need to be combined with whatever lacrimal surgery is appropriate. Stenosis of the punctum only is common and secondary to drying and keratinisation. This usually resolves spontaneously over several weeks with reapposition to the globe.

Punctal eversion can be difficult to assess if mild, but is obvious on blinking. This may be observed as a single entity and repaired with a tarso-conjunctival diamond excision, or it may be associated with tarso-ligamentous laxity. The degree of medial canthal tendon laxity is estimated by gently pulling the lid laterally and watching how far the punctum can be dragged (Figure 3.4): not quite up to the medial limbus of the cornea is best repaired with a Lazy-T procedure (Figure 3.4a); past the limbus but not up to the pupil, indicating laxity of the anterior limb of the medial

Figure 3.4 Lateral extent of punctal position in medial canthal laxity.

canthal tendon, can be corrected with a plication (Figure 3.4b); to the mid pupillary line and needing posterior limb plication (Figure 3.4c); or past the pupil and beyond with obvious rounding of the previously pointed corner of the medial canthus: this indicates loss of the posterior limb of the medial canthal tendon which needs reattachment to the posterior lacrimal crest area (Figure 3.4d).

Punctal ectropion without horizontal laxity can be corrected by a modified Lester Jones tarso-conjunctival diamond excision, taken from the internal, i.e. conjunctival surface of the eyelid. The lid is everted for surgery by gently pulling on the 00 lacrimal probe that has been placed in the lower canaliculus. The tarsal component is present in the lateral half of the diamond (Figure 3.5a). A long-acting, absorbable suture is used to close the wound by apposing the north and south corners of the diamond. Before burying the knot, the lower lid retractors should be included in the suture (Figure 3.5b). This will prevent the punctum from pouting outwards on downgaze. The retractors are found by going into the diamond with a fine pair of toothed forceps and grabbing the surface lying anterior to the conjunctiva inferior to the lower border of the tarsus. The correct layer has been picked up if, on asking the patient to look down without moving the head, a tug is felt through the forceps.

If punctual ectropion is accompanied by tarsal laxity but the medial canthus is essentially intact, which is often the case, a

Ectropion Medial Tarsoconjunctival Diamond Excision

Figure 3.5 Modified Lester Jones tarso-conjunctival diamond excision. (a) tarso-conjunctival diamond excised; (b) tarsal surface view of closure (00 probe in canaliculus).

Figure 3.5 Modified Lester Jones tarso-conjunctival diamond excision. (a) tarso-conjunctival diamond excised; (b) tarsal surface view of closure (00 probe in canaliculus).

horizontal shortening procedure (full thickness pentagon excision) lateral to the punctum is combined with the tarsoconjunctival diamond excision, as in Smith's Lazy T procedure. The incision lines he described (horizontal below the punctum, and vertical through the lid) look like the letter T lying down resting, hence the suggestion that the T is being lazy (Figure 3.6).

If the laxity is medial to the punctum, i.e. within the medial canthal tendon, and the punctum can be pulled to the medial limbus of the cornea but not much beyond, the anterior limb of this tendon needs to be shortened. This can be achieved with a plication of the anterior limb of the medial canthal tendon. A horizontal skin incision is placed just below the lower canaliculus, which is held taut against the globe with a 00 lacrimal probe. The incision extends from just lateral to the punctum (to permit exposure of the medial edge of the tarsal plate) to just medial to the medial canthal corner. Through this incision the anterior limb of the medial canthal tendon is identified and exposed. A non-absorbable suture is passed

Figure 3.6 Lazy T.

through the medial end of the tarsus just below the level of the punctum and through the medial canthal tendon in a position that is superior and posterior to that of the tarsal stitch (Figure 3.7).The suture is tied tight enough to overcome the medial laxity, but not so much as to cause punctal eversion.The postero-superior positioning of the medial end of the stitch is important to avoid anterior displacement of the whole medial canthal corner, which would aggravate the ectropion rather than cure it.

If it is possible to pull the punctum laterally up to the pupil, it is the posterior limb of the medial canthal tendon that is the major contributor to this laxity. It can be repaired with a plication of the posterior limb of the medial canthal tendon. A conjunctival incision is made in the fold behind the caruncle, although some prefer to open the conjunctiva immediately behind the plica semilunaris. This incision is extended anteriorly to the medial end of the tarsal plate. A 00 lacrimal probe is placed in the lower canaliculus to be sure of its position at all times. Its tip is used to indicate the position of the lacrimal sac, making it easier to identify the posterior lacrimal crest. It is this area that is exposed to allow fixation of one end of a non-absorbable suture. The other end is secured in the

Medial Canthal Tendon Plication
Figure 3.7 Medial canthal tendon plication anterior limb.

posterior surface of the medial end of the tarsus, close to its superior border (Figure 3.8). The knot is buried and the conjunctiva closed.

Medial canthal resection is more appropriate if the punctum can be pulled laterally beyond the pupil. Here the horizontal shortening is medial as well as lateral to the punctum. A vertical incision is made perpendicular to the lid margin, just lateral to the caruncle. This of course necessitates cutting through the inferior canaliculus (Figure 3.9a). An 00

Stitch

Tarsoconjuntival Diamond Excision

Figure 3.8 Medial canthal tendon plication -posterior limb.

Stitch

Figure 3.8 Medial canthal tendon plication -posterior limb.

lacrimal probe is maintained in the cut medial end of the canaliculus. As before, the tip of this probe can help in identifying the position of the posterior lacrimal crest. It is the periosteum just superior and posterior to this that is exposed with blunt dissection. The globe is kept safely lateral to the surgical site with small malleable retractors.

The degree of slack that can be taken up is measured by overlap until the lid margin is taut, as previously described. This portion is resected. A non-absorbable suture is placed as for posterior limb plication; however, before tying this, the cut medial end of the canaliculus is secured by marsupialisation and suturing to the top 1mm of the postero-medial corner of the newly shortened tarsus, with fine long-acting, absorbable sutures (Figure 3.9b). The skin closure is standard.

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