Ординатура / Офтальмология / Английские материалы / Clinical Ophthalmology A Systematic Approach 7th Edition_Kanski, Bowling_2011

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Fig. 1.55 (A) Severe bilateral involutional ptosis with high upper lid creases and deep sulci; (B) reasonable levator function, particularly on the left

Mechanical ptosis

Mechanical ptosis is the result of impaired mobility of the upper lid. It may be caused by dermatochalasis, large tumours such as neurofibromas (Fig. 1.56), heavy scar tissue, severe oedema and anterior orbital lesions.

Fig. 1.56 Mechanical ptosis due to a neurofibroma

Surgery

Anatomy

1The levator aponeurosis fuses with the orbital septum about 4 mm above the superior border of the tarsus (Fig. 1.57). Its posterior fibres insert into the lower third of the anterior surface of the tarsus. The medial and lateral horns are expansions that act as check ligaments. Surgically, the aponeurosis can be approached through the skin or conjunctiva.

2Müller muscle is inserted into the upper border of the tarsus and can be approached transconjunctivally.

3The inferior tarsal aponeurosis consists of the capsulopalpebral expansion of the inferior rectus muscle and is analogous to the levator aponeurosis.

4 The inferior tarsal muscle is analogous to Müller muscle.

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Fig. 1.57 Anatomy of the eyelid

Conjunctiva–Müller resection

1Indications include mild ptosis with levator function of at least 10 mm. This includes most cases of Horner syndrome and very mild congenital ptosis. The maximal lift is 2–3 mm.

2Technique. Müller muscle and overlying conjunctiva are excised (Fig. 1.58A) and the resected edges reattached (Fig. 1.58B).

Fig. 1.58 Conjunctiva–Müller resection. (A) Clamping of conjunctiva and Müller muscle; (B) appearance after excision and suturing

Levator resection

1Indications are ptosis of any cause provided levator function is at least 5 mm. The extent of resection is determined by the amount of levator function and the severity of the ptosis.

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2Technique involves shortening of the levator complex through either an anterior (skin – Fig. 1.59) or posterior (conjunctival) approach.

Fig. 1.59 Anterior levator resection. (A) Skin incision; (B) dissection and resection of levator aponeurosis; (C) levator reattachment to the tarsal plate

(Courtesy of AG Tyers and JRO Collin, from Colour Atlas of Ophthalmic Plastic Surgery, Butterworth-Heinemann 2001)

Brow suspension

1Indications

•Severe ptosis (>4 mm) with very poor levator function (<4 mm).

•Marcus Gunn jaw-winking syndrome.

•Ptosis associated with aberrant regeneration of the 3rd nerve.

•Blepharophimosis syndrome.

•Ptosis associated with 3rd nerve palsy.

•Unsatisfactory result from previous levator resection.

2Technique involves suspension of the tarsus from the frontalis muscle with a sling consisting of autologous fascia lata (Fig. 1.60) or non-absorbable material such as prolene or silicone.

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Fig. 1.60 Brow suspension. (A) Site of incisions marked; (B) threading of fascia lata strips; (C) tightening and tying of strips

(Courtesy of AG Tyers and JRO Collin, from Colour Atlas of Ophthalmic Plastic Surgery, Butterworth-Heinemann 2001)

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Ectropion

Involutional ectropion

Involutional (age-related) ectropion affects the lower lid of elderly patients. It results in epiphora and in long-standing cases the tarsal conjunctiva may become chronically inflamed, thickened and keratinized (Fig. 1.61).

Fig. 1.61 (A) Severe long-standing involutional ectropion; (B) keratinization of the tarsal conjunctiva

(Courtesy of R Bates– fig. B)

Pathogenesis

The following age-related changes are contributory:

1Horizontal lid laxity, which is demonstrated by pulling the central part of the lid 8 mm or more from the globe, with its failure to snap back to its normal position on release without the patient first blinking (Fig. 1.62A).

2Medial canthal tendon laxity, which is demonstrated by pulling the lower lid laterally and observing the position of the inferior punctum. If the lid is normal the punctum should not be displaced more than 1–2 mm. If laxity is mild the punctum reaches the limbus, and if severe it reaches the pupil (Fig. 1.62B).

3Lateral canthal tendon laxity, which is characterized by a rounded appearance of the lateral canthus and the ability to pull the lower lid medially more than 2 mm.

4 Disinsertion of lower lid retractors is occasionally relevant.

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Fig. 1.62 Pathogenesis of involutional ectropion. (A) Horizontal lid laxity; (B) medial canthal tendon laxity

Treatment

The methods of repair depend on the underlying aetiology and the predominant location of the ectropion as follows:

1Generalized ectropion is treated with horizontal lid shortening. This is achieved either by excision of a tarso-conjunctival wedge (Fig. 1.63) or increasingly with a lateral canthal sling procedure (see Fig. 1.66B).

2Medial ectropion may be treated with a medial tarsoconjunctival diamond excision, usually combined with a lateral canthal sling as horizontal laxity often co-exists.

3Medial canthal tendon laxity, if marked, requires stabilization prior to horizontal shortening to avoid excessive dragging of the punctum laterally.

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Fig. 1.63 Horizontal lid shortening to correct ectropion. (A) Vertical cut; (B) excision of a pentagon; (C) closure

(Courtesy of AG Tyers and JRO Collin, from Colour Atlas of Ophthalmic Plastic Surgery, Butterworth-Heinemann 2001)

Cicatricial ectropion

Cicatricial ectropion is caused by scarring or contracture of the skin and underlying tissues which pulls the eyelid away from the globe (Fig. 1.64A). If the skin is pushed up over the orbital margin with a finger the ectropion will be relieved and the lids will close. Opening the mouth tends to accentuate the ectropion. Depending on the cause, both lids may be involved and the defect may be local (e.g. trauma) or general (e.g. burns, dermatitis and ichthyosis).

1Mild localized cases are treated by excision of the offending scar tissue combined with a procedure that lengthens vertical skin deficiency, such as Z-plasty.

2Severe generalized cases require transposition flaps or free skin grafts (Fig. 1.64B and C). Sources of skin include the upper lids, as well as posterior auricular, preauricular and supraclavicular areas.

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Fig. 1.64 Correction of cicatricial ectropion. (A) Preoperative appearance; (B) free-skin graft in place; (C) postoperative appearance

(Courtesy of A Pearson)

Paralytic ectropion

Paralytic ectropion is caused by ipsilateral facial nerve palsy (Fig. 1.65A) and is associated with retraction of the upper and lower lids and brow ptosis; the latter may mimic narrowing of the palpebral aperture.

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Fig. 1.65 Paralytic ectropion. (A) Left facial palsy and severe ectropion; (B) lagophthalmos

(Courtesy of A Pearson)

Complications

1Exposure keratopathy which is caused by lagophthalmos (Fig. 1.65B).

2Epiphora is caused by malposition of the inferior lacrimal punctum, failure of the lacrimal pump mechanism and an increase in tear production resulting from corneal exposure.

Temporary treatment

Temporary treatment is aimed at protecting the cornea in anticipation of spontaneous recovery of facial nerve function.

1Lubrication with tear substitutes during the day, and instillation of ointment and taping shut of the lids during sleep are usually adequate in mild cases.

2Botulinum toxin injection into the levator to induce temporary ptosis.

3Temporary tarsorrhaphy, a procedure in which the lateral aspect of the upper and lower lids are sutured together, may be necessary, particularly in patients with a poor Bell phenomenon in which the cornea remains exposed when the patient attempts to blink.

Permanent treatment

Permanent treatment should be considered when there is irreversible damage to the facial nerve as may occur following removal of an acoustic neuroma, or when no further improvement is likely after Bell palsy. Treatment is aimed at reducing the horizontal and vertical dimensions of the palpebral aperture by one of the following procedures:

1Medial canthoplasty may be performed if the medial canthal tendon is intact. The eyelids are sutured together medial to the lacrimal puncta (Fig. 1.66A) so that the puncta become inverted and the fissure between the inner canthus and puncta is shortened.

2 Lateral canthal sling may be used to correct residual ectropion and raise the lateral canthus (Fig. 1.66B).

3Upper eyelid lowering can reduce the risk of exposure.

4 Gold weight implantation in the upper lid can assist closure.

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Fig. 1.66 Permanent treatment of paralytic ectropion. (A) Medial canthoplasty; (B) lateral canthal sling – refashioned canthal tendon fromthe lower lid is passed through a button hole in the tendon fromthe upper lid

(Courtesy of AG Tyers and JRO Collin, from Colour Atlas of Ophthalmic Plastic Surgery, Butterworth-Heinemann 2001)

Mechanical ectropion

Mechanical ectropion is caused by tumours on or near the lid margin (Fig. 1.67) which mechanically evert the lid. Treatment involves removal of the cause if possible, and correction of significant horizontal lid laxity.

Fig. 1.67 Mechanical ectropion

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