Ординатура / Офтальмология / Английские материалы / Fundamentals of Clinical Ophthalmology Plastic and Orbital Surgery_Collin, Rose_2001

PLASTIC and ORBITAL SURGERY

to periosteum. A forehead scalp flap is elevated using predominantly blunt dissection in the loose sub-galeal plane above the periosteum to within 2cm of the supraorbital rim centrally. Careful lateral dissection is undertaken avoiding seventh nerve branch damage.This is continued along the supraorbital rim with selective weakening surgery to the corrugator procerus and frontalis muscles avoiding damage to the supraorbital neurovascular bundles. A supraorbital periosteal incision may further enhance the procedure. Meticulous haemostasis throughout is essential before excision of excess flap tissue within the hairline.The wound is carefully closed in layers using deep 3/0 Vicryl and surgical staples or 4/0 Prolene, after placement of a supraorbital drain.The staples or sutures are removed seven to ten days post operatively.

Post operative haematoma leading to flap necrosis, localised sensory and motor nerve damage, hair loss and unacceptable scarring are all recognised complications, the majority of which can be avoided with careful surgical technique.

facilitating further dissection using endoscopic control.This proceeds inferolaterally along the temporal line with subsequent fascial incision, facilitating adequate release of the lateral brow. Dissection with release of the periosteum, galea and depressor muscles is then undertaken.

The brows are now free for fixation which may be effected in a number of ways. The most common method is screw fixation whereby a screw is placed in each lateral frontal incision site at a predetermined distance from the anterior margin of the incision. A skin hook then pulls the periosteum margin posteriorly; the incision site is closed with staples or suture so that the screw is now at the anterior part of the wound and the forehead lifted and fixated by the predetermined amount. Additional fascial fixation may then be undertaken prior to skin closure using 4/0 Prolene or staples.

Complications are as for those described with bi-coronal brow lift technique, although with the exception of nerve damage, they occur less commonly.

Endoscopic forehead and brow lift

This small incision technique is an alternative to the more extensive coronal brow lift. It facilitates brow elevation with coincident reduction of forehead creases whilst minimising scarring.

Two small vertical frontal incisions are made within the hairline on each side of the head down to bone followed by localised subperiosteal dissection, without endoscopic visualisation, backwards over the occiput, laterally over the parietal bone and towards the brow. Transverse temporal incisions, one on each side within the hairline, are then made on to deep temporalis fascia. These incisions are connected to the previously created subperiosteal dissection pockets, using blunt scissors, dissecting from the temporal incision centrally. The frontal and temporal spaces are joined to create an “optical cavity” thus

Eyelid surgery

Upper eyelid blepharoplasty

Excess upper eyelid tissue and/or herniated orbital fat can be excised for functional or aesthetic reasons. In the former the excess tissues abut or overhang the lash margin, thus interfering with visual function. Significant coincidental brow ptosis must be repaired or it will be worsened by blepharoplasty.

The incision is marked with the patient sitting up. A line is drawn along the skin crease starting above the superior punctum extending to the lateral canthus and then sloping upwards 1–1·5cm from the lateral canthus in a natural skin crease (Figure 8.4). The skin above this area is pinched vertically using fine tooth forceps, the lower jaw of which is positioned on the marked line such that excess skin is eliminated and the lids

Brow

Upper

punctum

Eyelid

Skin marking

Figure 8.4 Skin marking for upper eyelid blepharoplasty.

just touch with passive lid closure. The position of the superior jaw of the forceps is marked. This method of marking is repeated nasally and temporally and the marks joined with similar preparation of the other eyelid remembering to aim for a symmetric post operative appearance. If local infiltrative anaesthesia is used it is injected at this stage.

The skin is incised with a scalpel along the marked line and excised from the underlying orbicularis. A strip of orbicularis may be removed if the muscle is felt to be bulky or significant skin excision has been undertaken. Orbital fat excision is undertaken if appropriate. Excess upper lid fat is usually confined to the central and medial areas of the eyelid. An apparent lateral protrusion is invariably a prolapsed lacrimal gland which should not be excised but rather repositioned using plicating sutures between the anterior gland capsule and supraorbital rim. Fat prolapse is facilitated by incision through the orbicularis and underlying fat capsule; gentle pressure on the globe via the lower lid enhances fat prolapse. It is essential that the fat is handled carefully and gently to avoid unnecessary traction on posterior orbital fat and associated blood vessels. The excess fat to be removed is clamped and excised with cautery to the excision stump. Meticulous care is necessary throughout with particular regard to haemostasis.

COSMETIC SURGERY

If excess medial canthal skin is present then this is excised by extension of the medial incision superiorly with excision of redundant overlying skin. It is not necessary to close either orbital septum or the deeper layers of the eyelid. The skin is sutured with an over and over 6/0 Prolene centrally reinforced with individual sutures at the medial and lateral angulation, which are removed four to five days post operatively.

To minimise post operative bruising and facilitate healing, ice-packs are applied for 24 hours post operatively. The vision is checked hourly for the first four hours post operatively. The patient is advised to report sudden orbital pain or loss of vision immediately.

Lower eyelid blepharoplasty

Lower eyelid blepharoplasty is generally undertaken for cosmetic purposes. Three different approaches are described.

Anterior approach blepharoplasty

Anterior approach blepharoplasty is indicated in patients with excess lower eyelid skin and fat prolapse.

Technique – a subciliary incision is marked 1–2mm below the lash line starting inferior to the punctum, running across the lid to the lateral canthus and extending straight laterally for up to 1cm in the line of a natural skin crease (Figure 8.5). The skin is incised with a scalpel and deepened centrally on to the tarsus. A skin muscle flap is initially fashioned and elevated off the tarsus and septum, then extended laterally and medially using scissors. A 4/0 traction suture through the tarsus superior to the incision site allows controlled eyelid traction upwards which facilitates flap dissection. Dissection is continued inferiorly in the suborbicularis plane to the orbital rim, thereby exposing orbital septum throughout the lower eyelid. Orbital fat lies deep to the orbital septum and is prolapsed when the

PLASTIC and ORBITAL SURGERY

Medial

Lateral

Lower punctum

Skin marking

Figure 8.5 Skin marking for lower eyelid blepharoplasty.

septum is opened across the horizontal length of the eyelid. The fat is localised in three fat pads temporally, centrally and nasally and careful graded excision of the fat starting temporally and proceeding medially is undertaken with meticulous haemostasis, again avoiding unnecessary posterior traction. The skin muscle flap is swept superiorly on maximal stretch (with the patient looking up and the mouth open), excess flap tissue is marked and redundant skin and muscle then excised. The wound is closed with a single over and over 6/0 Prolene suture along the lid incision and interrupted 6/0 sutures laterally.

In cases with co-existent lid laxity a horizontal lid shortening procedure, in the form of either a lateral full thickness pentagon lid excision or lateral canthal sling, is undertaken before skin and muscle excision.

Similarly if co-existent mid-face ptosis is present then a mid-facelift may be necessary. Surgery to correct this should immediately precede any lid shortening procedure if this surgical combination is undertaken. The skin muscle flap is retracted downwards to expose the inferior orbital rim. Various techniques have been described to undermine and elevate the cheek, or mid-face, tissues. In the SOOF (suborbital orbicularis oculi fat) lift a cheek flap is raised at the periosteal level; alternatively a subperiosteal flap may be fashioned. With either approach, dissection is continued inferiorly to the level where the cheek bone ends and nasally towards the nasolabial fold, taking care to avoid infraorbital

nerve damage.With the subperiosteal approach the periosteum is incised 2–3mm below the orbital rim with inferior dissection and periosteal release such that the cheek flap is freely elevated. The latter is attached superiorly to the periosteum of the lateral orbital wall and orbital rim with interrupted 4/0 Prolene such that the ptotic cheek is lifted upwards and laterally. Excess skin and muscle are excised and the skin closed as for conventional blepharoplasty.

Ice packs are applied in the immediate post operative period with regular assessment of the vision as with upper lid blepharoplasty.

Transconjunctival blepharoplasty

Transconjunctival blepharoplasty is indicated in patients with fat prolapse but without excess skin.

The lower eyelid is infiltrated with local anaesthesia subcutaneously and transconjunctivally down to the orbital rim. A marginal traction suture is placed and the lid everted over a Desmarres retractor. The conjunctiva is incised 4mm below the inferior tarsal margin, extending the width of the eyelid, using scissors, cutting cautery or laser. The incision is carried through the deeper tissues until fat is exposed.The incision is held open with outward and downward traction which facilitates fat exposure. The fat capsule is incised with judicious fat excision from the three fat pads as appropriate and meticulous haemostasis, again avoiding unnecessary posterior fat traction. The conjunctival incision can either be left unsutured or closed with interrupted 6/0 absorbable sutures.

Post operatively ice packs are applied with regular visual assessment as for conventional blepharoplasty.

External direct lower eyelid blepharoplasty

This procedure is reserved for excision of significant lower eyelid tissue in the form of festoons.

The skin and excess underlying tissues to be excised are outlined taking care to position the excision symmetrically and, if possible, in a co-existent lid crease in the area overlying the inferior orbital rim. The skin and deeper tissues are incised followed by excision of all excess tissue using scissors. Haemostasis is secured. Layered closure with careful skin margin approximation using a 6/0 subcuticular Prolene suture is undertaken which is removed five to seven days post operatively.

COSMETIC SURGERY

Fat excision may be inadequate or excessive. Significant excess fat excision will result in a hollowed out appearance particularly apparent in the lower lid. Surgery in the form of suborbicularis oculi fat transposition may be necessary to rectify this asymmetry. If fat excision has been limited then further fat removal may be necessary.

Lid asymmetry as a consequence of improperly positioned incisions is described. The most noticeable asymmetry relates to asymmetric skin crease positions which if unacceptable will require revisionary surgery.

Blepharoplasty complications

Blindness is described as occurring in between 1:10 000 and 1:40 000 cases. It only occurs when the orbital compartment is entered with fat excision and is thought to be related to traction on the posterior orbital vessels with subsequent orbital haemorrhage.

Diplopia is an uncommon complication of blepharoplasty usually related to damage to the inferior oblique muscle.

Ptosis may occur transiently or permanently. It is caused by either direct damage or significant stretching of the levator muscle.

Inadequate or excessive skin excision may result in a number of complications. If excess upper lid skin is excised lagophthalmos results which may or may not be a permanent feature. More marked excess upper lid skin excision may result in frank lid margin rotation and ectropion. Excess skin removal from the lower lid can result in rounding of the lateral canthal region with enhancement of scleral show and frank lid margin ectropion or lid retraction. Excess skin removal is the commonest significant complication following blepharoplasty. The abnormal lid position may respond to vigorous regular lid massage but often recourse to revisionary lid surgery is necessary. Inadequate skin removal requires further skin excision.

Lasers in oculoplastic surgery

The use of lasers in oculoplastic surgery has become increasingly widespread of late. Two lasers are at present pre-eminent in the field; the carbon dioxide and more recently erbium YAG lasers. The basic principle for all these lasers is that of delivering high laser energy in short pulses or bursts, thus maximising tissue ablation whilst minimising adjacent thermal damage and hence scarring.The current lasers produce these short burst effects either by the provision of a super or ultra pulse pattern such as the Coherent CO2 laser or Erbium YAG or a continuous wave laser which is interrupted by a rapidly moving mechanical system such as the Sharplan laser.

A number of carbon dioxide laser systems are currently available for oculoplastic surgery. Carbon dioxide lasers have both tissue ablative and haemostatic properties which make them ideally suited for both incisional and resurfacing surgery.

The Erbium YAG laser delivers increased tissue ablation with co-incidental reduction of adjacent thermal damage when compared to the carbon dioxide laser. This results in reduced tissue damage, erythema and post operative inflammation. The major disadvantages of the erbium YAG are lack of coagulation, so that it is not suitable for incisional surgery, and lack of contractile

PLASTIC and ORBITAL SURGERY

effect when used for resurfacing which may be important in the maintenance of medium to long term effects.

Skin resurfacing

Laser skin resurfacing is used to smooth facial skin and reduce wrinkles or rhytides. Dynamic rhytides resulting from underlying muscle activity, i.e. glabellar folds do not respond as well as static rhytides, i.e. periocular folds caused by ageing and ultraviolet exposure. The technique of laser skin resurfacing results in vaporisation of the epidermis and upper dermal layers with subsequent repair resulting in an improved cosmetic appearance. This relatively precise skin ablation with reduced thermal damage results in a more reproducible and superior result than alternative techniques such as dermabrasion or chemical peels.

Patients for laser resurfacing should be carefully selected and understand the aims and limitations of laser treatment.A thorough history with particular emphasis upon the use of topical skin preparations, allergies and sensitivities and previous herpetic infections is taken. Fair skinned patients (Fitzpatrick grades 1 and 2) are ideal for resurfacing whereas darker skinned individuals (Fitzpatrick grades 3 and 4) run a risk of post laser hyperpigmentation and should be approached cautiously. Laser resurfacing is contra-indicated in patients with deeply pigmented skin (Fitzpatrick grades 5 and 6). Pre-operative photographs with detailed diagrams and sketches are mandatory.

Technique of carbon dioxide laser resurfacing

Pre-operative skin preparation may be necessary in certain patients. Prophylactic anti-virals, i.e. Zovirax and oral antibiotics are frequently used and started 24 hours pre-operatively. If limited areas are being resurfaced, i.e. periocular or perioral regions only, then local anaesthesia, either infiltrative

or regional nerve blocks, with or without intravenous sedation is used. Full face resurfacing is best undertaken using local anaesthesia and sedation or general anaesthesia.

Laser safety precautions must always be observed which include protection of areas not being treated with wet swabs and/or protective eye shields. Anaesthetic equipment if used, must be protected using silver foil around the exposed endotracheal tube and connection and all theatre staff, including the surgeon, must wear protective goggles.

Techniques for resurfacing vary greatly from one surgeon to the next but all adhere to certain basic tenets. The skin thickness varies considerably over different parts of the face with the periocular skin being the thinnest and skin over the cheek and chin the thickest. In order to achieve a similar improvement in each area more laser treatment or resculpting is necessary with the thickest tissues.

The skin is thoroughly cleansed with saline and dried. The area of treatment is outlined and any deep wrinkles individually marked. The laser pattern and power are set, the laser tested and treatment commenced. The initial treatment centres on the individual wrinkles or scars outlined, with treatment to the shoulders or elevated areas adjacent to the deeper wrinkle or scar. The ablated debris is removed with saline soaked gauze swabs. Confluent laser passes are then made over the entire region or regions to be treated, taking care to avoid significant overlap of the laser pattern. The number of passes with the laser is dependent on the region of skin treated and the laser characteristics. Usually 1–2 passes are all that is required when treating periocular skin whilst 2–4 passes may be necessary in areas of thicker skin such as the forehead, cheeks or chin. All desiccated tissue must be carefully wiped away with saline swabs after each pass (Figure 8.6). Assessment of the depth of treatment is facilitated by recognised colour changes occurring in the tissues.

Complete epithelial removal results in a pinkish appearance; treatment to the papillary dermal layer correlates with a yellow/orange coloration whilst deeper reticular dermal ablation is characterised by a chamois leather or white appearance.Treatment should stop at this latter stage as deeper laser treatment may well lead to hypertrophic scarring.

It is important to avoid a frank demarcation line between areas of treated and untreated facial skin. This is facilitated by feathering or blending of the adjacent areas whereby laser treatment using reduced power and wider spacing is undertaken.

Post operatively it is essential to keep the treated area moist or covered at all times until re-epithelialisation has occurred which is usually complete within five to seven days. Many techniques have been described ranging from regular applications of aqueous cream and cleansing through to custom designed dressings.

After re-epithelialisation it is again important to keep the treated area moist. Most patients elect to use a combined moisturising concealer preparation until the erythematous phase of the treatment (lasting anything up to three months from the time of laser treatment) has settled. It is essential that the patient treats the newly resurfaced skin very carefully, rather like a baby’s skin. Direct sunlight must be

Figure 8.6 Periocular laser resurfacing with CO2 laser.

COSMETIC SURGERY

avoided and a sunblock preparation always used when outdoors, ideally long term.

Most post operative problems, assuming that laser treatment has been appropriately undertaken, result from poor skin care. Redness or erythema is to be expected and may take up to three months or more to settle. Hyperor rarely hypo-pigmentation can occasionally occur. The former can be managed with topical skin bleaching agents or steroid preparations but there is relatively little that can be offered for hypo-pigmentation.

Incisional surgery

The carbon dioxide laser can be used for tissue cutting as in blepharoplasty. The improved haemostasis allows for better visualisation during surgery, more rapid surgery and less post operative bruising and discomfort. Incisional laser surgery is particularly useful in transconjunctival blepharoplasties. Fat excision can be more carefully controlled with regard to both the amount of tissue excised and haemostasis at excision, without requirement for clamping of the fat to be excised. The possibility of undue posterior traction on the fat is therefore virtually abolished; the latter may well prove to be an important advantage of laser over conventional techniques. When transconjunctival blepharoplasty is combined with periocular resurfacing, very acceptable results can be achieved in patients with general wrinkling and skin laxity, and associated fat prolapse, without the complications normally associated with conventional subciliary blepharoplasty and skin excision.

ErbiumYAG laser

The principles of resurfacing with the erbium YAG laser are broadly similar to those outlined using the carbon dioxide laser.The skin change colours characteristic of carbon dioxide laser resurfacing, are not seen with the erbiumYAG. Break through punctate bleeding occurs as a consequence of lack of coagulation which,

PLASTIC and ORBITAL SURGERY

although useful in assessing the depth of treatment, is a limiting factor when undertaking deeper resurfacing. The recovery, in particular the duration of post operative erythema, with erbium YAG resurfacing is significantly reduced compared to the carbon dioxide laser and this appears to be its major advantage.

At the present time the carbon dioxide and erbium YAG lasers should be considered as complementary. As such the oculoplastic surgeon should be familiar with and have access to both systems.

Further reading

Alster TS, Apfelberg DB. Cosmetic Laser Surgery (1st ed.) New York: Wiley-Liss Inc, 1996.

Collin JRO. A Manual of Systematic Eyelid Surgery (2nd ed.) Oxford: Butterworth-Heinemann, 1989.

De Mere M, Wood T, Austin W. Eye Complications with Blepharoplasty or Other Eyelid Surgery. A National Survey. Plast Reconstr Surg 1974; 53:634–7.

McCord Jr CD, Tanenbaum M, Nunery WR. Oculoplastic Surgery (3rd ed.) New York: Raven Press, 1995.

Putterman AM. Cosmetic Oculoplastic Surgery (3rd ed.) Philadelphia: WB Saunders Company, 1999.

The absence or loss of an eye is of enormous psychological significance to any patient. Socket surgery is directed at enabling the patient to wear a comfortable cosmetic ocular prosthesis which is stable and free from discharge. Removal of the eye and or orbital tissues may be necessary as a result of trauma, infection, tumour, the consequence of a painful eye or to remove a cosmetically unattractive globe. Depending upon the nature of the pathology the globe should be removed by evisceration, enucleation or exenteration.

Evisceration

The procedure involves the removal of ocular contents, retaining the scleral coat (Figure 9.1). There is no involvement of the meninges or optic nerves so little risk of backward spread of infection.The operation is less traumatic than enucleation and normally results in minimal bleeding; this may be of particular significance in the presence of orbital inflammation. The ocular remnant is fully mobile and there is less late orbital fat atrophy.

A contra-indication to evisceration is the theoretical risk of subsequent sympathetic uveitis although if uveal tissue is carefully removed the incidence of this condition appears extremely low. This surgery should not be performed when there is a risk of local tumour recurrence or when an intraocular

tumour cannot be excluded. Furthermore, histological assessment of the specimens obtained at the time of evisceration are difficult to interpret.

Evisceration can be performed with or without keratectomy. The ocular contents are evacuated with an evisceration spoon introduced into the supra-choroidal space. Haemostasis is achieved by packing, and all remnants of uveal tissue should be carefully removed. The scleral cavity can be swabbed with dressed orange sticks moistened with absolute alcohol.

In the presence of suppuration the scleral envelope may be packed open and allowed to heal by secondary intention. In primary closure, if keratectomy has been performed, two triangles of sclera are excised at 9 and 3 o’clock allowing secure closure over an implant. The evisceration is completed by a three layered closure, sclera, Tenon’s capsule and finally conjunctiva, using 5/0 Vicryl (Figure 9.1).

Enucleation

This procedure (Figure 9.2) involves the removal of the entire globe by severing the attachments of the extra-ocular muscles and optic nerves.This is the technique of choice in the presence of an intra-ocular tumour as histological specimens are easily obtained. There is no associated risk of sympathetic ophthalmitis. The surgery requires care to

Figure 9.1 Evisceration. (a) 360° peritomy, anterior chamber opened, cornea removed, two triangles of sclera excised at 3 and 9 o’clock; (b) evisceration spoon used to remove contents of globe, scleral shell cleaned; (c) scleral shell closed with 5/0 Vicryl.

prevent socket contracture or late post operative fat atrophy.

A 360° peritomy is made in the conjunctiva and Tenon’s capsule is carefully separated from the globe. The four rectus muscles are identified and tagged with double ended 5/0 Vicryl sutures. The two oblique muscles are cut or the inferior oblique may be tagged and sutured to the inferior border of the lateral rectus, 10mm posterior to its free edge. The optic nerve is sectioned with scissors or a snare. The globe is removed and the socket packed, using gauze soaked in iced saline to achieve haemostasis.

An ocular implant is generally inserted, either within Tenon’s capsule or posterior to the posterior part of Tenon’s capsule. Deep

(d)

(e)

Figure 9.2 Enucleation. (a) 360° peritomy; (b) four rectus muscles disinserted, oblique muscles cut, optic nerve divided, globe removed; (c) wrapped spherical orbital implant inserted, rectus muscles saturated to implant; (d) tenons capsule closed, muscle sutures brought out through conjunctiva; (e) conjunctiva closed.

placement of the orbital implant in this site posterior to Tenon’s capsule allows a larger volume to be implanted and reduces the incidence of implant migration or extrusion. The orbital implant may be of inert material, for example silicone ball or one that allows fibrovascular ingrowth, for example Medpor and Hydroxyapatite. Implants are wrapped in a synthetic mesh or donor sclera.The four rectus muscles are attached to the implant. The superior rectus should not be placed too anteriorly to minimise the incidence of upper lid retraction or ptosis.When using Hydoxyapatite, holes should be made in the wrap to allow the attachment of the extra ocular muscles and to facilitate fibro-vascular ingrowth. Muscle sutures are then placed through the conjunctival fornices to improve prosthesis mobility.Tenon’s capsule and conjunctiva are closed carefully in two layers. A conformer, with a large central drainage hole should be inserted post operatively and left in place until a prosthesis is fitted at approximately six weeks.

Enucleation is not appropriate in the presence of endophthalmitis nor where a malignant tumour may have spread to extraocular structures. In this case an exenteration should be performed. An orbital implant is normally inserted at the time of primary enucleation but may be avoided in the presence of intraocular malignancy or in a very inflamed orbit where the incidence of post operative extrusion is high.

Exenteration

This involves the total excision of the orbital contents, with or without the removal of the eyelids. Indications for this surgery are advanced malignancy, either of the eyelid, the globe or surrounding adnexal structures. The extent of the procedure depends upon the size and extent of the tumour. If the tumour of the globe does not involve the eyelid skin the lids may be retained but they must be sacrificed in the presence of an extensive skin tumour.

SOCKET SURGERY

An elliptical incision is made through the skin and deep tissues to the bone of the orbital rim. The periosteum is separated from the bony orbit; the trochlea, medial and lateral canthal tendons are detached. The apical structures, including the optic nerve, are cut and the orbital contents are removed within the periosteum. The orbit may be allowed to heal by granulation or a split skin graft used to line the bony cavity.

If the eyelid skin is to be preserved the periorbital skin is undermined, the lid margins are sacrificed and the resultant skin edges sutured together. The dead space behind the skin is gradually obliterated as the skin adheres to the bony orbit. Any attempt to replace the volume within the orbit using a thick skin flap or temporalis muscle may make the detection of local recurrences more difficult.

Orbital implants

When the globe is removed its volume cannot be replaced solely with an ocular prosthesis. By replacing orbital volume in the form of a orbital implant a light artificial eye can be fitted.

Box 9.1 Calculation of implant volume

Ideal implant volume 6ml

Many shapes have been suggested but a sphere is routinely used as it has the maximum volume for a given surface area. An 18mm sphere has a volume of 3ml and when wrapped this increases to 4ml. Studies have