Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Early diagnosis and complete excision is essential. Mapping biopsies of the superior and inferior tarsal and bulbar conjunctiva are performed to exclude multicentric origin and pagetoid spread. The histologist should be alerted to use the appropriate lipid stains. Orbital exenteration is indicated in patients with diffuse involvement of the lid or conjunctiva. Radiation therapy plays a palliative role.

■Melanoma: represents <1 % of eyelid neoplasms. Lesions are irregularly pigmented (Fig. 1.34), but a large minority may lack pigmentation. Other features include inflammation and bleeding. Clinical forms include lentigo maligna, superficial spreading, and nodular melanoma. Metastases are common in the latter two forms. The Breslow thickness predicts the average time to metastasis. The cure rate for lesions

<0.75 mm thick approaches 100%.

Excise lesions <1.5 mm thick with wide margins and reconstruct. Lesions >1.5 mm require additional neck lymph node scintigraphy and biopsy. Involve nuclear medicine, and

Fig. 1.34: Melanoma.

OCULOPLASTICS 1 Chapter

Facial Dystonias

Clinical features The facial dystonias include benign essential blepharospasm and hemifacial spasm. Increasingly frequent blinking and periocular spasms may lead to social embarrassment, anxiety, depression, and, ultimately, functional blindness.

Examination Record the position and degree of spasm or fasciculation diagrammatically. Perform a full ocular and cranial nerve examination (including corneal sensation). Note any lid margin disease or tear film abnormalities.

Investigations Refer patients with hemifacial spasm, recent or rapid onset blepharospasm, or blepharospasm with other neurological features (e.g. reduced corneal sensation) to a neurologist for assessment and neuroimaging. Those with longstanding, stable symptoms and without other neurological signs do not require investigation.

Management overview Botulinum toxin injections improves symptoms in >90% of patients. An empirical approach is required to identify the optimum dose: more than one set of injections may be required for adequate control of spasms. Where toxin injections do not control symptoms without causing side effects, a protractor myectomy is effective, although toxin injection may continue to be required. A frontalis sling may be helpful in patients with pretarsal apraxia (that is, inability to

open the eyelids due to spasms of the pretarsal orbicularis), once the spasm has been controlled by toxin injections. Surgery (protractor myectomy or brow suspension) is indicated in about 10% and 4%, respectively. Protractor myectomy will relieve symptoms in about two-thirds of patients, and brow suspension in > 90%.

Botulinum toxin injections All volumes and dosages given below are for Dysport and are not applicable to other preparations of toxin. Reconstitute one vial of Dysport with

2.5 mL 0.9% sodium chloride BP for injection, yielding a solution of 20 units per μL (according to the manufacturer’s instructions).

Complications Ptosis, diplopia, entropion, ectropion, exposure keratitis, and allergy.

Contraindications Known hypersensitivity, history of myopathy, bleeding disorders, pregnancy/lactation.

OCULOPLASTICS 1 Chapter

45

Facial dystonias

46

Fig. 1.37: Botulinum toxin injections for blepharospasm and hemifacial spasm.

Week 1 (first clinic visit):

1. Blepharospasm and hemifacial spasm:

Dysport is given in six locations around the eye, all locations receiving 20 units (Fig. 1.37) with the exception of the lateral upper lid, where 40 units is given.

For patients with evidence of pretarsal spasm 10 units of Dysport is given in two locations on the upper lid (topical anaesthetic cream may be required).

2.Aberrant facial nerve regeneration and myokymia: lower initial doses.

3.Treat dry eye or blepharitis.

4.Inform patients about support groups, e.g. The Dystonia Society, and provide information leaflet if available.

Week 2:

1.Spasm controlled: continue the same regimen every 3–4 months as required.

2.Spasm not controlled: further injection(s) to muscles that remain in spasm. Reviewed 1 week later (Week 3).

Week 3:

1. Spasm controlled: review in 3 months. If further botulinum toxin is indicated, the dose given is the sum of the previous two injections.

2. Spasm not controlled: further injection(s) to muscles that remain in spasm. Review 1 week later (Week 4).

Continue this cycle until either the spasm is controlled or the side effects of treatment become intolerable.

Surgery

■Offer protractor myectomy (extended blepharoplasty via a cosmetic blepharoplasty incision) to patients in whom toxin injections are ineffective and/or induce intolerable side effects (ptosis, facial droop, rectus muscle paralysis, or allergic response).

■Facial nerve avulsion is a shorter operation with lower perioperative morbidity, and is reserved for the elderly and infirm. The duration of effect is shorter and the procedure carries more complications than protractor myectomy.

Further management

■Induced ptosis as side effect of controlling pretarsal spasm: trial of ptosis props.

■Ptosis props not tolerated due to dry eyes or a spastic Bell’s phenomenon: avoid brow suspension.

■Ptosis props tolerated: offer brow suspension. Use supramid prolene suture or silicone rod, which can easily be reversed if surgery is not tolerated.

■Spastic Bell’s phenomenon (eyeball rolls under upper eyelid despite adequate control of spasm): offer systemic centrally acting medication e.g. clonazepam.

OCULOPLASTICS 1 Chapter

Congenital eyelid disease

Congenital Eyelid Disease

Blepharophimosis-ptosis-epicanthus inversus syndrome

Clinical features An autosomal dominant disorder (gene defect on chromosome 3), characterized by a variable degree of ptosis with poor levator function, epicanthus inversus, blepharophimosis (narrowing of the horizontal palpebral aperture), telecanthus (canthal displacement due to soft tissue anomaly), hypertelorism (canthal displacement due to a wide nasal bridge), and lower lid ectropion. Other associated features include hypoplasia of the tarsal plate, prominent vertical brow hair, a flat brow, and female infertility.

Management Urgently prevent amblyopia (p. 26); otherwise elective surgery may be deferred until age 3–4, when nasal bridge growth begins, the tissues are larger, and the epicanthic folds reduce in size. A mild epicanthic fold is corrected with a Y–V plasty over the medial canthal tendon (MCT). A Z-plasty alone over the epicanthic fold(s) is indicated where there is no telecanthus. Telecanthus is corrected by resecting the middle portion of the MCT and suturing the ends together. A transnasal wire, which draws the MCTs toward the midline, may be indicated in hypetelorism, and in severe cases of telecanthus, where medial canthal bone requires removal in addition to medial canthal soft tissue. Ptosis surgery is carried out after the medial canthoplasty, and usually requires brow suspension with autogenous fascia lata. A full-thickness skin graft to the upper and lower lids may also be required.

and is an indication for urgent upper lid surgery. Small to mediumsize defects (<50% of lid width) may be repaired by pentagon wedge excision of the anomalous tissue with direct closure, with or without lateral cantholysis. Larger defects require staged surgery with a lower to upper lid switch flap and subsequent division of the flap. A forced duction test is performed, conjunctival traction bands are excised, and forniceal foreshortening is managed with buccal mucous membrane graft(s). Monitor for amblyopia.

Distichiasis

See page 21.

Epiblepharon

Clinical features An excess fold of skin and muscle in the lower lid. In severe cases, lash–globe contact may occur.

Management The majority of cases resolve spontaneously. Where there is no entropion, everting sutures are indicated. Where the lower lid is turned in, excision of a strip of skin and muscle is performed.

OCULOPLASTICS 1 Chapter

Eyelid trauma

Eyelid Trauma

Background Broad groups of eyelid injury are recognized, but any combination may occur:

■Lacerating trauma.

Uncomplicated :

±lid margin laceration.

Complicated by injury to : levator complex, lacrimal apparatus, globe, orbit, sinuses, cranium.

±retained lid or orbital foreign body (FB).

■Blunt trauma (contusion, avulsion of lid).

■Chemical injury.

History A carefully documented history is often medicolegally important. Note the following:

■The time and nature of an alleged assault or FB, as well as the distance and trajectory.

■Whether parts or all of the FB have been recovered.

■Other ocular symptoms.

■ENT symptoms including epistaxis and CSF rhinorrhoea.

Examination

■Record VA.

■Accurately document or preferably photograph the extent of any wound, noting if it is partial or full thickness. Note any involvement of the lid margin(s), lacrimal drainage apparatus, or posterior lamella.

■Exclude anterior segment, (p. 205), posterior segment (p. 551), and orbital injury (p. 101).

Investigations Imaging is chiefly to exclude bony injury, retained FB, gas, and pus. A plain skull X-ray is quick and readily available but ultrasound and CT may be appropriate. Avoid MRI if metal FBs are suspected.

General principles of repair

Eyelid trauma

Specific injuries

■Lid margin : Repair using the same principles as a pentagon wedge excision (see page 10).

■Levator palpebrae complex: thoroughly clean the wound and approximate corresponding tissue as accurately as possible. Do not extend the wound to identify further structures because spontaneous resolution of the ptosis may occur, up to 6 months post-injury and the ptosis may in part be due to a neuropraxia.

■Medial canthal tendon : even in cases of avulsion, a residual stump of deep tissue may often be grasped with toothed forceps, and approximated to the medial cut end of the tarsus using a 5/0 suture (absorbable or nonabsorbable) on a fishhook or half-circle needle.

■Canaliculus : controversy exists regarding the repair of injury to a single canaliculus, as adequate tear drainage may occur via the healthy fellow canaliculus, and the failure rate is high due to ring contracture. However, if repair is undertaken, a monocanalicular self-retaining silicone stent may be placed (shorten the stent before insertion). Identification of the cut proximal end of the canaliculus within the wound is aided by application of 10% epinephrine on a cotton bud (the transected end appears as a pale ring), or by syringing through the fellow canaliculus with fluorescein or air. The bellshaped end of the stent fits in the punctal ampulla flush with the punctum. The stent does not require suturing and may easily be removed at 2–3 weeks as epithelialization occurs within a few days. The presence of a stent will not prevent tissue contracture, which occurs over many months. This technique avoids the use of the pigtail probe, which, depending on the design of the probe and the experience of the surgeon, may lead to injury of the healthy canaliculus. Alternatively, if sufficient distal canaliculus is present, this can be opened along its posterior surface by a few millimetres, and marsupialized into the conjunctival sac with an 8/0 absorbable suture. Where both canaliculi are injured, repair by an experienced surgeon is indicated. A silicone rod may be used and tied in the nose. The risk of failure is high. If subsequent dacryocystorhinostomy with retrotubes fails, a Lester Jones tube may be indicated.