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34 3 Sutures and Suturing
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Fig.3.11 Cotton bud as an aid to suturing. a Apply skin counterpressure over the suture needle tip
until it penetrates. b Engage the needle tip in the cotton bud. c Pull the needle completely through
by rotating the bud. d Apply 180° counterrotation to the bud and pull the suture through by lifting
the bud
Note: Although the technique has been broken down into individual steps, in
practice they blend into one smooth movement [1].
3.5 Take Home Message
•
The horizontal mattress and the magic suture techniques are powerful and
underused.
•
A cotton bud can be used as a surgical instrument when suturing thin skin.
Reference
1. Cotton Bud: An Aid to Suturing. YouTube video: https://youtu.be/K2-_QzJhW5U
Pertinent Anatomy
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4.1 Overview
•
Lid Layers
•
Surgical landmarks.
An understanding of functional lid anatomy is essential if you are to avoid
getting lost and have successful surgical outcomes. The upper and lower lids are
analogous in structure save for a few important differences which I shall highlight.
4.2 The Lid Skeleton (Fig. 4.1)
4
The eyelids are attached to orbital rim by the medial and lateral canthal tendons
(known by some as canthal ligaments) and by the orbital septum. The tarsal plates
and canthal tendons together make up the eyelid skeleton. Repair any disruption
to their integrity as a priority.
4.2.1 Canthal Tendons
The canthal tendons are inelastic. The tarsal plate, on the other hand, stretches
slowly under sustained load. The medial lid margin is pulled posteriorly towards
the posterior lacrimal crest by Horner’s muscle (formerly thought to be a posterior
limb of the medial canthal tendon). The medial canthal tendon arises from the
periosteum of the anterior lacrimal crest, and the lateral canthal tendon from the
lateral orbital tubercule situated just inside the orbital rim.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
V. Th a l l e r, Eyelid Surgery, https://doi.org/10.1007/978-3-031-31527-5_4
35
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Orbital Septum
Upper Tarsal Plate
Lateral Canthal Tendon
Arcus Marginalis
Fig. 4.1 Eyelid skeleton. The tarsal plates and canthal tendons together make up the eyelid
skeleton
Horner’s Muscle
Medial Canthal Tendon
Lower Tarsal Plate
Orbital Septum
4.2.2 Orbital Septum (7 Veils)
The orbital septum arises from the arcus marginalis of the orbital rim and separates the orbital from the pre-orbital compartments. Though spoken of as a single
layer and contrary to common belief, the orbital septum is made up of seven layers. This can be a cause of confusion during surgery for the uninitiated when, after
having divided one or more septal layers further ones are found. The septum is relatively inelastic. This is the reason orbital pressure can rise dangerously high with
a retrobulbar haemorrhage. The septum also restricts medial and lateral movement
of the lid margin and may need to be divided if you are trying to move a section
of lid margin to a new position. Scarring and contraction of the septum cause lid
margin retraction.
4.3 Lid Layers (or Lamellae) (Fig. 4.2)
Think of the lid as a two-layer sandwich. We call the layers ‘lamellae’.
4.3.1 Anterior Lamella (Fig. 4.2a)
The outer lid layer (anterior lamella) is made up of skin and orbicularis muscle.
These are closely bound together by the orbicularis fascia, though this attachment
weakens with age. So, dissection is easier in the sub-orbicularis plane than in the
4.3 Lid Layers (or Lamellae) (Fig. 4.2) 37
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ab
Fig. 4.2 Eyelid layers. a Anterior lamella = Skin and Orbicularis. b Posterior lamella = Tar s a l
plate and Conjunctiva
Orbicularis
Skin
Conjunctiva
Tarsal Plate
subcutaneous plane. This is of practical significance when performing blepharoplasty. Removing excess skin together with its attached orbicularis is quicker and
easier than separating the two. External to the orbital rim always dissect in the
subcutaneous plane to avoid damaging facial nerve branches which run on the
muscular layer. Remember this when raising periocular flaps.
Confusingly some surgeons have recently begun to refer to the orbicularis as a
separate ‘middle lamella’ because it can be used as a vascular flap to support both
an anterior and a posterior free graft.
4.3.2 Posterior Lamella (Fig. 4.2b)
The inner lid layer (posterior lamella) is made up of tarsal plate and conjunctiva. The conjunctiva is inseparably bound to tarsal plate. Proximal to the tarsal
plate border the conjunctiva is bound progressively less tightly to the overlying
Muller’s muscle. Lower lid Muller’s muscle is not surgically visible and can only
be discerned microscopically.
4.3.3 In-Between
The sandwich filling, between the anterior and posterior lamellae, contains the
orbital septum, the insertions of the retractor muscles via their aponeuroses, and the
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palpebral arteries and veins. The pre-aponeurotic fat pads lie between the orbital
septum anteriorly and the retractor aponeurosis posteriorly.
There is no distinct levator muscle in the lower lid. Instead, inferior rectus
movement is transmitted to the lower lid by a fibrous aponeurosis known as the
capsulo-palpaebral head. As in the upper lid, this lies immediately posterior to the
preaponeurotic fat pad.
4.4 Skin
Eyelid skin is very thin, mobile, and elastic. It has no underlying fat (unlike
other skin). With aging the skin usually thins (except in patients with severe sun
damage), stretches and loses elasticity.
4.4.1 Skin Tension Lines (Langer’s Lines) (Fig. 4.3)
Karl Langer, a Viennese anatomist, plotted the direction in which skin punctures
made in fresh cadavers elongated due to inherent skin tension. By joining the
puncture axes, he drew lines that are named after him. More recently skin tension
has been measured in living subjects resulting in slightly different line orientations.
Siting surgical incisions along such tension lines minimizes the tension across the
healing scars, making them stretch less and consequently less visible. However,
when there is significant skin loss do not align the closure scar with the tension
lines or you will cause ectropion and/or interfere with eyelid movement. Instead,
close the wound to align the closure tension tangentially to the lid margin. The
resulting scar orientation is usually perpendicular or oblique to the skin tension
lines.
Fig. 4.3 Skin tension lines.
These indicate the direction
of maximal tension within the
skin
4.5 Don’t Get Lost (Surgical Landmarks) (Fig. 4.4) 39
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4.5 Don’t Get Lost (Surgical Landmarks) (Fig. 4.4)
It is easy to get lost in the lid layers, especially during re-operations. Apart from
the skin anteriorly, and the conjunctiva posteriorly, only two landmarks are con-
stant within the eyelid. They are the tarsal plate and the pre-aponeurotic fat pad
(Fig. 4.5). Use them to orientate yourself during surgery. When re-operating on a
scarred lid start dissecting in a previously uninvolved area where the tissue planes
are still clear and develop your surgical plane from there.
Fig. 4.4 Don’t get lost
Pre-aponeurotic
fat fad
Tar sal Pla te
Fig. 4.5 Surgical landmarks. The two constant landmarks are tarsal plate and preaponeurotic fat
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Fig. 4.6 Tarsal plate and meibomian glands. Alignment of the meibomian glands that make up
70% of the tarsal plate and open onto the lid margin
4.6 Tarsal Plate (Fig. 4.6)
Tarsal plate is a distinctive, firm, pale tissue that extends away from the eyelid
margins. Meibomian glands (approx. 30 per lid) make up 70% of it. They are
aligned side by side and held together by collagen and elastin (Fig. 4.6). Tarsal
plate is the strongest layer of the eyelid margin and must be repaired following
lid margin lacerations or incisions. Note that unlike tendon, tarsal plate stretches
progressively under tension. This makes a tarsal strip a poor substitute for a lateral
canthal tendon. Respect tarsal plate as there are no good substitutes to replace it
with (cartilage being much stiffer).
4.7 The Meibomian Orifice Line
The meibomian orifice line marks the mid tarsal plate plane at the lid margin. You
can make it more visible by squeezing the lid margin and looking for the egress of
Meibomian secretions. Sutures placed in the Meibomian orifice line will engage
tarsal plate and thus gain firm lid margin purchase (which can be used for lid
traction).
4.8 The Grey Line
The grey line marks the junction of the anterior and posterior lamellas. Though
frequently referred to in textbooks it is a poor anatomical landmark as it becomes
increasingly difficult to discern with age. Its only surgical significance is when
splitting the lid margin into its two lamellae.
The grey line derives its colour from the underlying muscle of Riolan (modified
terminal orbicularis) as seen through the extremely thin lid margin skin. Because
4.11 Blood Supply (Fig. 4.7)41
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of this, and contrary to common practice, sutures placed in the grey line have
almost no holding strength and serve no useful function.
4.9 Pre-aponeurotic Fat
Pre-aponeurotic fat, unlike other fat, is extremely fine without visible globules.
Deep yellow in colour, it flows at body temperature. You can encourage preaponeurotic fat to prolapse through a septal incision by pressing on the eye or
on the opposing lid. Anteriorly the fat pad is contained by the orbital septum. The
structure immediately posterior (deep) to the pre-aponeurotic fat is, by definition,
the levator aponeurosis in the upper lid and the retractor aponeurosis in the lower
lid.
4.10 Lacrimal Ductules
The lacrimal gland, which sits superotemporally between the upper lid lamellae,
secretes tears into the upper conjunctival fornix via one or several lacrimal duc-
tules. Take care to avoid damaging them during surgery. As they are not easily
visible you should identify and mark the ductules before you operate. Do this
by first doubly everting the upper lid over a large Desmarres retractor, and then
instilling a drop of Fluoresceine 2% onto the conjunctiva laterally. Wait and watch
until you see tears from the ductule opening dilute the orange fluoresceine to make
it fluoresce green. This reveals the ductule openings which you should mark with
ink for easy identification when you operate.
4.11 Blood Supply (Fig. 4.7)
Eyelids possess an excellent anastomosed blood supply. This enables them to heal
quickly and protects wounds from infection. It also makes lids bleed a lot during
surgery. There are two main bleeding points in the eyelid margin – the marginal
and the peripheral vascular arcades (Fig. 4.7). The marginal arcade lies on the
anterior surface of the tarsal plate, deep to orbicularis, just proximal to the lash
roots. The peripheral arcade lies on Muller’s muscle in the upper lid, close to the
proximal border of the tarsal plate. [Note: Most textbooks only show a single arcade
in the lower lid, but surgical experience tells a different story]. Knowing the vessel
location makes accurate diathermy easier. To perform diathermy, first squeeze the
full thickness of the cut lid sandwich with forceps and clean away any blood with a
cotton bud (Fig. 4.8a). Then identify the bleeding points as you slowly release the
pressure and bleeding restarts (Fig. 4.8b). Diathermy the cut vessels (Fig. 4.8c).
The two arcades unite into a single palpebral artery and vein at either end of
the lid.
42 4 Pertinent Anatomy
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Peripheral Vascular
Arcade
Marginal Vascular
Arcade
Palpaebral Arteries
Fig. 4.7 Eyelid vascular arcades. The marginal arcade is on the anterior tarsal plate surface close
to the margin. The peripheral arcade lies on Müller’s muscle, just proximal to the tarsal plate. They
join at either end to form the palpaebral arteries
a b
Marginal Vascular Arcade
Peripheral Vascular Arcade
c
Fig. 4.8 Eyelid bleeding points. a Grasp and squeeze the lid margin and remove the blood. b Gen-
tly ease the forceps pressure until bleeding restarts to reveal the cut vessels. c Apply diathermy to
the bleeding vessels
4.12 Muscles 43
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4.12 Muscles
The eyelid closing muscle (protractor) is the orbicularis oculi. This is a thin sheet
of concentrically arranged muscle fibres extending from the lid margin to well
outside the orbital rim. It is customary to consider it in three functional parts:
the pretarsal, the pre-septal and the orbital, even though they are a continuum
(Fig. 4.9). The pretarsal orbicularis is responsible for blinking, whereas the orbital
part performs strong lid squeezing. The pre-septal orbicularis takes part in both
but also serves a lid stabilizing function that is lost if it is allow migrate to a
pretarsal position through weakening of the orbicular fascia. Loss of orbicularis
function may result in incomplete eye closure. Bell’s reflex (involuntary upward
rolling of the eyes on attempted eye closure) mitigates the consequent corneal
exposure. Loss of orbicularis function may also give rise to lower lid paralytic
ectropion. Occasional involuntary contraction of the orbicularis is called a tick,
when persistent and unilateral, hemi facial spasm, and when persistently bilateral,
the idiopathic blepharospasm syndrome.
The eye-opening muscle (retractor) of the upper lid is the levator palpebrae
superioris (Fig. 4.10a & b). It shares the same innervation as the superior rectus
muscle (upper division of the oculomotor nerve). It inserts into the orbicular fascia
at the level of the skin crease and into the anterior surface of the mid and lower
tarsal plate. Its function is modulated by Muller’s muscle by up to 2 mm. Muller’s
muscle is a thin sheet of sympathetically innervated muscle that originates from
the under surface of the levator and inserts into the upper border of the tarsal
plate. At its insertion it is closely bound to the conjunctiva but becomes easier
to separate surgically higher up. Paralysis of the sympathetic nerve supply, as in
Horner’s syndrome, causes no more than 2 mm of ptosis.
Unlike the upper lid, the lower lid does not have a separate retractor. This function is performed by the capsulo-palpebral head of the inferior rectus. Likewise,
the lower lid does not have a surgically visible Muller’s equivalent.
Fig. 4.9 The orbicularis oculi. Artificial subdivision of the continuous orbicularis sheet into functional parts: pretarsal for blinking, pre-septal for stabilization, and the orbital for squeezing
Orbital
Pre-septal
Pre-tarsal
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