Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Canthal (palpebral) ligaments

■Tether the tarsi to the periostium medially and laterally.

■The medial canthal ligament has an anterior limb, which inserts anterior to the lacrimal crest, and a posterior limb, which inserts into the posterior lacrimal crest.

■The lateral palpebral ligament attaches the lateral tarsus to Whitnall’s tubercle within the orbital rim.

Orbital septum

■Consists of planes of tough fibrous tissue which form a barrier to the spread of infection.

■Origin: arcus marginalis at the orbital rim.

■Insertions:

1. Superiorly : the levator aponeurosis;

2. Inferiorly : the lower lid retractors just beneath the tarsus; 3. Medially : the posterior lacrimal crest;

4. Laterally : Whitnall’s tubercle.

OCULOPLASTICS 1 Chapter

Eyelid anatomy revision

Upper lid retractors

■The striated levator palpebrae superioris (LPS) muscle is innervated by the oculomotor nerve, and has a common origin with the superior rectus muscle. Anteriorly, it becomes the levator aponeurosis as it passes anterior to Whitnall ligament, and inserts into the anterior tarsal surface. Medial and lateral extensions, or horns, insert into the periostium of Whitnall’s tubercle laterally, and into the medial canthal tendon medially. A few anterior fibres pass through the orbicularis to form the skin crease. Contraction of LPS produces 12–20 mm of upper lid elevation.

■The sympathetically innervated Müller’s muscle arises from the posterior surface of the levator muscle, and inserts into the superior border of the tarsus. Contraction elevates the lid by up to 2 mm.

Whitnall’s ligament (superior transverse ligament)

■A fascial condensation stretching from the trochlea medially to lacrimal gland fascia laterally, 10–12 mm above the tarsus.

Lower lid retractors

■Arise as the capsulopalpebral head of the inferior rectus, passing forward as a fascial sheet which envelops the inferior oblique muscle and inserts into the inferior tarsus.

■A sympathetically innervated portion lies immediately posterior to the aponeurotic portion, arising from the fascial sheath of the inferior rectus muscle and inserting into the inferior tarsus.

■Contraction on down gaze results in 3–7 mm of lower lid depression.

Grey line

■The mucocutaneous junction situated behind the eyelashes.

■A grey line split opens the space between the orbicularis muscle and tarsus, dividing the eyelid into anterior and posterior lamellae.

History

Identify factors which influence disease risk, subsequent management, and prognosis. Old photographs may help determine if changes are congenital or acquired. If surgery is planned, ask about anticoagulants (NSAIDs, antiplatelet agents, warfarin) and plaster allergies. The history depends on the presenting complaint

– the two commonest situations are lid lesions (Table 1.1) and lid malposition (Table 1.2).

Table 1.1: Lid lesions

OCULOPLASTICS 1 Chapter

5

Examination

Examination

Sit directly opposite the patient. Ocular and eyelid observations must be recorded with each eye fixating in turn, or false measurement will be obtained. Note any facial asymmetry and record the following:

Best corrected visual acuity of each eye.

Margin reflex distance (MRD):

MRD 1: Upper lid margin to central corneal light reflex.

MRD 2: Lower lid margin to corneal reflex.

■MRD gives more information than palpebral aperture (PA), the vertical distance between the upper and lower eyelid margins. For example, a patient with unilateral ectropion and ptosis may have a similar PA to the normal side.

■In a child only PA may be measurable.

■Where the lid contour is abnormal, record the PA at the medial and lateral limbus, and centrally.

Levator function (LF) Typically 15–20 mm in the adult.

■Block compensatory frontalis activity when measuring LF. Hold a ruler vertically before the eye, between thumb and first finger. The second and third fingers rest firmly on the brow to overcome frontalis activity.

■Measure the maximal vertical excursion of the upper lid, from down gaze to up gaze.

■Note relative lid height in downgaze. In congenital levator dystrophy the lid is higher than the fellow. In acquired ptosis (aponeurotic dehiscence) the lid is lower.

Skin crease (SC) 7–8 mm in men, 9–10 mm in women.

■Marks the fulcrum of activity of the levator palpebrae muscle on the eyelid, and is formed where levator fibres attach to the skin.

■Measure the distance between the lid margin and skin crease(s) in down gaze.

Upper lid show (ULS) Distance between the lid margin and skin fold (not crease) in primary position. ULS asymmetry is a cause of patient dissatisfaction.

Lagophthalmos Residual interpalpebral distance with gentle closure. Ask if there is nocturnal lagophthalmos.

Scleral show (SS) Distance between the lid margin and the superior, and inferior, limbi, with each eye fixating the target in turn.

Hang up in down gaze (failure of upper lid to descend normally). May occur with levator dystrophy, previous ptosis surgery, thyroid eye disease and orbital disease.

Additional observations

■Lid lag (phase lag on down gaze – a dynamic process).

■Cogan’s twitch (overshoot of upper lid on elevation from

OCULOPLASTICS 1 Chapter

Ectropion

Background Age-related ectropion is common, but exclude other causes.

Classification

■Age-related.

■Cicatricial: due to shortage of skin – may occur with ageing, trauma, previous lower lid surgery, overflow of tears/topical medication.

■Paralytic: e.g. facial nerve palsy due to any cause.

■Mechanical: from a lower lid mass such as a meibomian cyst or neoplasia.

Symptoms Epiphora, intermittent red eye, mucous discharge.

Signs Part or whole of the lower lid is everted from the globe. Other changes may be present, e.g. dermatochalasis, ptosis, punctal stenosis.

History and examination Note any previous lid surgery, trauma, and assess facial nerve power.

1.Age-related:

■Horizontal laxity: lower lid fails to snap back when distracted from the globe.

■Lateral and medial canthal ligament laxity: note the degree of punctal displacement with lateral traction, e.g. to the medial limbus or medial pupil.

■Retractor laxity causing tarsal (shelf) ectropion: the tarsal conjunctiva may be inflamed/thickened from chronic exposure; punctal stenosis is commonly present.

■Orbicularis muscle hypotony: assess for lagophthalmos, upper lid retraction, assess Bell’s phenomenon, upgaze, and corneal sensation.

2.Anterior lamella cicatricial changes:

■Ask the patient to open his/her mouth and look up. In the presence of significant cicatricial changes, the lid cannot be apposed to the globe.

■Assess the extent of available skin in the upper lids and pre/postauricular areas as part of surgical planning.

OCULOPLASTICS 1 Chapter

Ectropion

Treatment For temporary relief place Micropore tape horizontally along the lower lid skin and then up onto the temple region to provide lift.

Surgery :

■The main principle is the correction of horizontal lid laxity, usually with a full-thickness pentagon wedge excision laterally (Box 1.1), or a lateral tarsal strip (Box 1.2).

■Medial ectropion with punctual eversion may require a medial (‘diamond’) tarso-conjunctivoplasty. A punctoplasty may also be indicated. The ‘lazy T’ procedure is a medial pentagon excision plus medial tarso-conjunctivoplasty (the posterior lamella scar forms a ‘T’).

■Medial ectropion due to medial canthal tendon laxity (i.e. the posterior limb) will not be addressed by repairing the anterior limb alone. Significant medial laxity may require a medial canthal fixation suture, or medial wedge excision with an anchoring suture between the medial cut end of the tarsus and the periosteum of the posterior lacrimal crest (‘medial wedge’). In paralytic cases, a medial (Lee) canthoplasty helps to raise the lower lid.

Box 1.1: Pentagon wedge excision

1.Consent:

■Benefit: improved lid position.

■Risks : recurrence of ectropion; overand undercorrection; scarring; inflammation; infection; suture granuloma (with nonabsorbable suture); further surgery. May produce bruising, conjunctival chemosis, and subconjunctival haemorrhage.

2.Instil topical anaesthetic into the conjuctival sac.

3.Inject 1–2 ml of 2% lidocaine with 1:200 000 epinephrine through the skin, at either end of the eyelid (27 or 28-gauge needle).

4.Use straight scissors to make a full-thickness cut through the eyelid at the junction of the lateral third and medial two-thirds of the eyelid. Overlap the cut edges to decide how much to shorten, and resect this amount, in the form of a pentagon (Fig. 1.4).

Box 1.1: Pentagon wedge excision—cont’d

6.Pass each needle of a double 7/0 Vicryl suture through each grey line. Place the suture on traction with an artery clamp and rest this on the forehead – this aligns the tarsal edges while the tarsal sutures are placed.

7.Align the cut tarsal edges with two 6/0 Vicryl sutures. Take large bites of the tarsus; lay the knots anteriorly. Further deep sutures may be used to close the orbicularis inferior to the tarsus.

8.Now tie the 7/0 Vicryl suture through the grey line, with the knot lying within the wound. A lash line suture completes correct alignment of the lid edges. If the apposition of the lid margins is imperfect, sutures are removed and replaced.

9.Close the skin with 3–4 7/0 Vicryl sutures.

10.Apply Oc. chloramphenicol, Vaseline gauze, and eye pad for 24 hours. The absorbable skin sutures may be left in situ, although are frequently removed at first review in 10–14 days.

7/0 Vicryl grey line suture (similarly placed suture through lash line not ilustrated)

‘Grey’ line

Lower of 2 sutures through tarsal plate - note not through conjunctival surface. Upper tarsal suture not shown

OCULOPLASTICS 1 Chapter

Ectropion

Box 1.2: Lateral tarsal strip (LTS)

1.Consent:

■Benefit: improved lid position.

■Risks : recurrence of ectropion; overand undercorrection; scarring; inflammation; infection; suture granuloma (with nonabsorbable suture); further surgery. May produce bruising, conjunctival chemosis, and subconjunctival haemorrhage.

2.Inject local anaesthetic subcutaneously via a 27 or 28-gauge needle to the lateral canthal region, followed by gentle pressure.

3.Perform a lateral canthotomy by making a horizontal cut at the lateral canthus (straight scissors).

4.Ensure haemostasis

5.Grasp the lateral end of the lower lid (Adson’s dissecting forceps) and perform cantholysis of the subconjunctival bandlike attachments (Fig. 1.5, arrow) between the lid and orbital rim (straight sharp scissors).

6.Dissect between orbicularis and the tarsus and divide the two by staying posterior to the grey line (straight scissors). The corresponding mucocutaneous strip of lid margin is removed.

7.Cut a tarsal strip 3–4 mm wide and ≈5 mm long, lower edge parallel to the lid margin. Pare off the conjunctiva on the strip (D15 blade).

8.Perform lateral (2 mm) upper lid grey line split to enhance subsequent vertical lift (‘augmented LTS’).

9.Attach the LTS to the periosteum using double-ended 5/0 undyed Vicryl. Expose the lateral orbital rim (straight or spring scissors) and spread orbicularis fibres aside (tips of the Moorfields forceps, held in the left hand, straddle the orbital rim and maintain the view of the periosteum).

10.Pass the suture ends through the inner orbital rim periosteum – 2 mm higher than the level of the medial canthus – by rolling the needle from inside the rim anteriorly.

11.Pull both ends through equally, but not completely, to leave a small loop. Place this loop over the LTS (Fig. 1.6A). Pass one needle through the end of the LTS laterally, and one medial to the loop (Fig. 1.6B). Tighten the suture to ensure a sufficiently high placement on the orbital rim and reposition if necessary.