Eyelid Laceration Repair

Lacerated eyelids are commonly associated with traumatic injuries such as bite wounds and automobile injuries. They should be repaired as soon as possible to protect the cornea and maintain an effective blink reflex. Healing of lid lacerations by secondary intention may result in considerable fibrosis and distortion of the eyelids and lid margin, and secondary scarring of the corneal surface. Direct reapposition is possible if one-third or less of the lid margin is missing. More extensive injuries require advancement flaps or grafts for repair. Preservation of the eyelid margin and its associated structures is essential for normal eyelid function. No matter how thin a flap of tissue has been created by a laceration running parallel to the eyelid margin, it should not be excised (Fig. 17-3). If these flaps do not survive, the eyelid margin can be reconstructed.

Apply topical lubricating ointment to keep the tissue moist before surgical repair. Thoroughly irrigate and gently cleanse the wound with a dilute 10% Betadine solution. Identify the mucocutaneous junction, the meibomian glands in the tarsal plate, and the palpebral conjunctiva. Convert simple lacerations to a V-shaped defect with judicious wound debridement (scarify necrotic margins and smooth jagged edges), taking care to preserve as much tissue as possible (Fig. 17-4, A) if needed for alignment (optional). Place a marginal skin suture, ensuring that the lid margin has perfect alignment (Fig. 17-4, B). Leave the conjunctival tissue to heal on its own. Take care that knots and suture ends do not abrade the cornea by positioning them subcutaneously, or place knots on the outside of the eyelid by passing the suture through the eyelid. Use a simple interrupted or modified figure-8 cruciate suture (e.g., 4-0 to 5-0 Vicryl) with the knot ends directed away from the cornea to close the skin (Fig. 17-4, C, D). Space remaining skin sutures approximately 2 to 3 mm apart. If the nasolacrimal duct has been damaged by trauma near the medial canthus, stent it by first cannulating the nasolacrimal duct with 0 to 2-0 monofilament suture and then passing polyethylene or Silastic tubing over the suture and securing it to the skin near the medial canthus and the lateral canthus of the nostril (see inset, Fig. 17-4). A complete temporary tarsorraphy may be indicated to protect the cornea after repair of extensive eyelid injuries because of impaired eyelid functions and blink reflex (Fig. 17-5). Medicate the wound with a broad-spectrum ophthalmic antibiotic ointment such as neomycin/polymyxin/bacitracin for 14 days, and monitor for blepharospasm, tearing, or holding the eye closed (mucopurulent discharge is common with topical antibiotic ointments); this may indicate that a corneal ulcer has formed. Remove sutures at 10 to 14 days. Leave the cannula in place for 4 to 6 weeks.

Conjunctival and Corneal Lacerations

Conjunctival lacerations without eyelid lacerations rarely require surgical repair because they heal rapidly. They are allowed to heal by secondary intention after debris has been removed and topical antibiotics applied. Conjunctival sutures are not necessary. Apply broad-spectrum topical ophthalmic antibiotics such as neomycin/polymyxin/bacitracin to prevent infection.

Deep corneal lacerations (>50% corneal stromal thickness) and perforations are surgical emergencies, and surgery should be performed as soon as they are discovered. These surgeries require an operating microscope and thus are best referred to a veterinary ophthalmologist. If a specialist is not available and the perforation or laceration site has plugged with fibrin or iris, medical management should be considered to try to prevent infection or stabilize the site until it can granulate by corneal vascularization. If the perforation site leaks aqueous humor for longer than 24 hours, enucleation or referral for corneal repair may be required.

For corneal perforations, use eye solutions rather than topical ointments because ointments may cause severe uveitis if they are absorbed into the anterior chamber. Evaluate the intraocular structures for evidence of additional trauma. Remove superficial foreign material embedded in the cornea with irrigation, forceps, and minimal dissection.

Medical treatment of a corneal perforation or laceration includes topical antibiotics, atropine, and systemic antibiotics. Antibiotics should be broad spectrum (e.g., ofloxacin for Gram-negative coverage, cefazolin 50 mg/ml in LRS [refrigerate] for Gram-positive coverage [1 drop every 1 to 2 hours for 24 to 48 hours, then every 4-6 hours]) until the lesion has vascularized. Corneal vascularization starts to develop after 3 to 5 days and grows on average 1 mm/day, so healing of a corneal perforation can take several weeks. If corneal vascularization does not develop; internal eye infection occurs; or the perforation site enlarges and leaks, surgery is necessary to repair or remove the eye. Atropine administered topically will reduce cycloplegia and minimize posterior synechiae. Systemic antibiotics with broad-spectrum coverage should also be used to try to prevent the development of internal eye infection.

For superficial corneal lacerations, a soft bandage contact lens reduces corneal exposure and will produce increased comfort. Adjunctive treatment also includes topical use of a tissue adhesive (n-butyl cyanoacrylate or absorbable methoxypropyl cyanoacrylate monomer). Remove any corneal epithelium over the ulcer bed, and dry the surface of the cornea with cellulose sponges or air. Using a 23 or 25 g needle or a similar applicator, apply a small volume (1 drop) of adhesive directly to the wound in a smooth, thin layer. Apply a restraint collar such as a hard E-collar until the ulcer has healed, typically in 7 to 28 days. Soft E-collars might allow the patient to rub the eye on objects like the floor and furniture, and would not be effective protection.

Adhesive polymerization occurs within a few seconds, and the material becomes very hard. Tissue adhesive may be considered for deep ulcers, but the heat from drying can cause corneal perforation. The adhesive has low tissue toxicity, is bacteriostatic, and inhibits melting of corneal stroma. Adhesive is extruded (2 to 4 weeks) as the cornea heals.

Temporary Tarsorrhaphy

Temporary tarsorraphy may be performed after correction of entropion, ectropion, eyelid lacerations, or eyelid mass removal, to help prevent wound contracture during healing. Tarsorraphies are also indicated when the patient cannot blink, but should be avoided for deep corneal ulcers, deep corneal lacerations, or corneal perforations.

Place horizontal mattress sutures at the eyelid margins to appose them, using partial-thickness bites oriented parallel or perpendicular to the lid margin (see Fig. 17-5).

Conjunctival Flap

Conjunctival flaps are used to treat deep corneal ulcers, descemetoceles, and small sealed corneal perforations. Conjunctival flaps typically are harvested from the bulbar conjunctiva and are integrated into the cornea with healing over a few weeks; they provide a protective covering that brings blood vessels and fibroblasts to facilitate healing. The flap remnant typically leaves a heavy, opaque scar. Plan the flap so it is several millimeters larger than the defect it must cover.

Perform a Seidel test to determine if small full-thickness corneal lacerations have sealed by placing sodium fluorescein on the cornea; then, without irrigation, observe to see whether a clear river of aqueous humor is running through the fluorescein (this indicates that the corneal perforation is not sealed). If the cornea leaks, these cases are best referred to an ophthalmologist because repair typically requires use of an operating microscope.

Prepare a thin, sliding conjunctival flap by grasping the conjunctiva with ophthalmic tying forceps such as a 0.3 mm Colibri forceps approximately 2 mm from the limbus. Apply traction to tent the conjunctiva, and incise a few millimeters from the limbus with a pair of tenotomy scissors (Fig. 17-6, A). Elevate the cut edge, bluntly dissecting perilimbally with tenotomy scissors to separate the conjunctiva from the underlying sclera (Fig. 17-6, B). Using the tips of the tenotomy scissors directed at a 90-degree angle to the tissue, use sharp dissection to separate the episclera from the conjunctiva. Start the dissection at the free edge of the conjunctiva, and move the scissors proximally as the episclera is separated from the conjunctiva. Take care to prevent iatrogenic button-holes in the conjunctiva. After dissection, the conjunctival flap becomes much more mobile, reducing the chance of flap retraction. Position the flap over the defect after it has been debrided to remove any corneal epithelium. Be sure to debride the corneal epithelium off the corneal ulcer bed and edges before placing the tissue flap so the flap can integrate into the cornea.

Hood Flap

Dissect a hood flap from the bulbar conjunctiva dorsal to the lesion or from the bulbar conjunctiva as close to the lesion as possible (Fig. 17-7, A and B). Dissect half of the bulbar conjunctiva and separate it from the episclera as described previously; position it over the globe. Ensure that the conjunctiva lies flat on the cornea with no traction; this will occur if the episclera has been well dissected from the conjunctiva with tenotomy scissors (see Fig. 17-7, B). Place two absorbable sutures (6-0 to 8-0 Vicryl) at the limbus 180 degrees apart to position the flap over the cornea (Fig. 17-7, C). Provide tension across the free edge of the flap (not on the eye) to keep it in place over the cornea; corneal sutures are not required. Place partial-thickness sutures into the episclera or sclera in a simple interrupted pattern with 6-0 to 8-0 Vicryl (Gilger et al, 2007). If needed, place additional limbal sutures to further anchor the flap.

360-Degree Conjunctival Flap

Start a total or 360-degree conjunctival flap by making a 360-degree conjunctival incision 2 to 3 mm from the limbus, (Fig. 17-8, A and B). Carefully dissect the conjunctiva ventromedially from the episclera and the third eyelid tissues.

The third eyelid may be displaced centrally with the conjunctival graft over the eye. After the conjunctiva has been dissected from the episclera, it should stretch easily over the corneal surface (Fig. 17-8, C).

If the graft has a great deal of retraction, dissect the episclera more proximally from the conjunctiva with tenotomy scissors, taking care not to cause button-holes in the conjunctiva. Suture the free edges of the conjunctiva together in a horizontal mattress pattern (Fig. 17-8, C and D) using absorbable suture (6-0 Vicryl or smaller). Ensure that the sutures are tight, so that no corneal contact is made by sutures and the conjunctival graft is sutured to itself and not to the cornea (Gilger et al, 2007). It is important to get epithelial-to-epithelial apposition without flap overlap. Medicate the eye with broad-spectrum ophthalmic antibiotics (see previous laceration medical management description) at least four times a day and atropine once or twice daily. In the nonadherent areas, trim the flap with tenotomy scissors under topical anesthesia with proparacaine 6 to 8 weeks after surgery, once the corneal lesion has healed, allowing the corneal attachment to atrophy and undergo fibrosis, thus minimizing scar formation. Loose and excess conjunctiva can be trimmed from the cornea to reduce the vascular reaction and subsequent scar, but do not remove the conjunctiva from the former corneal ulcer or defect. Scar remodeling occurs over several months; final results vary from an insignificant opacity to a dense leukoma.

Third Eyelid Flap

Third eyelid flaps serve as physiologic bandages to support and protect the cornea after trauma. They are easier to create than conjunctival flaps but should not be used on deep corneal ulcers, descemetoceles or corneal perforations, which usually are fragile and require visual monitoring to direct aggressive medication management (see p. 294).

Exteriorize and extend the third eyelid by grasping it with forceps and elevating it. Pass a cutting needle with swaged-on 3-0 or 4-0 monofilament absorbable suture through the upper eyelid in the dorsolateral conjunctival fornix (Fig. 17-9, A). Direct the needle through the external surface of the third eyelid under the crossbar of the T-shaped cartilage, and exit through the external surface of the third eyelid on the opposite side of the cartilage. Alternatively, to reduce the chance of the suture rubbing on the cornea, direct the suture around the cartilage, but do not penetrate the conjunctiva on the bulbar surface of the third eyelid (Fig. 17-9, B). Direct the suture back through the dorsolateral conjunctival fornix and out the upper eyelid. Apply tension on the suture, pulling the third eyelid over the cornea. Tie the suture over a stent, with the ends long enough to tie a bow, so that the cornea may be inspected periodically (Fig. 17-9, C). As an alternative, use double-armed 3-0 to 2-0 nonabsorbable suture, and begin by placing the suture midway along the length of the third eyelid and then through the fornix.

Enucleation or Exenteration

Enucleation is probably the most common orbital surgical procedure performed in small animal practice. Common indications for enucleation include irreparable corneal or intraocular injury, unmanageable endophthalmitis, intraocular neoplasia, severe proptosis, and intractable uveitis. An additional indication might include painful end-stage glaucoma, although this can be treated with globe-sparing procedures (intrascleral prosthesis). All other options should be considered before enucleation is performed, particularly for sighted or potentially sighted eyes. However, under the right circumstances, enucleation can provide rapid resolution to chronic painful eye disease, at the same time eliminating the need for topical medications in the affected eye (Cho, 2008).

Exenteration is indicated for intraorbital neoplasia or ocular neoplasia that has extended beyond the globe. Owners may be resistant to either procedure, despite the fact that it may improve the animal’s quality of life.

Transconjunctival, transpalpebral, and lateral enucleation techniques are described here. The technique chosen should reflect the pathologic circumstances of the eye to be removed, patient anatomy, and surgeon preference. With all techniques, excessive traction on the globe and optic nerve should be avoided (particularly in cats) because traction on the optic chiasm during enucleation has been reported to result in permanent postoperative blindness in the remaining eye. Ligation or cautery of the nasolacrimal openings in the surgery site may be considered in brachycephalic dogs. Histopathologic evaluation of the globe and any other removed tissue of concern should always be performed.

The transconjunctival enucleation technique is commonly used. Advantages of this approach compared with other methods include reduced orbital tissue loss (reduced postoperative orbital sinking) and reduced intraoperative bleeding. However, this technique may not be preferred for infectious conditions of the anterior segment, such as severely infected corneal ulceration. The sterile surgical site may be exposed to a contaminated ocular surface, allowing for possible spread of infectious agents into the orbit. This situation is worsened by rupture of the cornea because intraoperative pressure on the globe may expel infected material from the eye. In these cases, transpalpebral enucleation may be a better choice, especially in dogs (Cho, 2008).

Transconjunctival Enucleation

Using heavy scissors, make a wide lateral canthotomy to improve exposure (Fig. 17-10, A). You may wish to clamp the area to be cut with a straight hemostat before incising to reduce hemorrhage. Place a lid speculum (optional). Next, make a 360-degree bulbar conjunctival incision around the limbus using small blunt scissors, such as Stevens tenotomy or small Metzenbaum scissors (Fig. 17-10, B). At the level of the orbital rim, use curved Metzenbaum scissors to bluntly dissect down through the bulbar conjunctiva to the subtenon space to expose the extraocular muscle tendons. Incise the tendons with scissors close to the globe (Fig. 17-10, C). Optionally, use small hemostats to clamp these areas before cutting to reduce hemorrhage. The ability to freely rotate the globe almost 360 degrees indicates that at least the recti and oblique muscles are cut.

Using a curved hemostat, clamp the tissues of the posterior pole of the globe, containing the optic nerve, retractor bulbi muscle, and associated vasculature (Fig. 17-10, D). Do not pull the globe or place any traction on the eye because this could avulse the optic nerve at the optic chiasm and blind the other eye. Leave the hemostat in place if space allows, or if necessary remove it before blindly incising the stalk with curved Metzenbaum or enucleation (more strongly curved) scissors about 5 to 10 mm posterior to the globe. Be sure to transect the optic nerve and avoid cutting the posterior sclera. Control hemorrhage from the orbit with direct pressure, hemostatic clamps, electrocautery, and/or calcium alginate. Avoid the optic nerve with cautery unless the equipment is appropriate for use around the brain or spinal cord such as Cameron-Miller cautery. Ligation of vessels and/or the optic nerve, although possible, is technically difficult and may not be necessary.

Also remove the orbital lacrimal gland and all conjunctiva (Fig. 17-10, E). Remove the lid speculum and broadly incise the base of the nictitans; clamping before cutting may again reduce hemorrhage. Remove the entire nictitans, including cartilage and gland at the base. Remove the eyelid margins with heavy straight scissors, starting at the lateral canthotomy (Fig. 17-10, F). Fully excise the smooth hairless lid margin so that the skin edges will close without excessive dead space or tension. The medial canthal area must be removed. The medial canthus is closely adhered to its deeper attachments, so sharp dissection is sometimes required. Large vessels are occasionally encountered at the medial canthus. Copiously flush the orbit with sterile saline.

A variation of subconjunctival enucleation improves access to the posterior pole of the globe and may reduce traction on the optic nerve. Begin the procedure by making a lateral canthotomy, and remove the lid margins and nictitans. The remainder of the globe dissection proceeds as for subconjunctival enucleation, as described earlier. With lid margins and nictitans out of the way from the start, additional surgical space is available around the globe.

To improve postoperative cosmesis following enucleation, several techniques have been employed in addition to closure of the orbital septum, including orbital mesh placement, sphere implantation, a combination of the two, and tissue reconstruction. Placing an orbital meshwork is simple. A taut continuous pattern of 3-0 to 5-0 monofilament nonabsorbable suture (nylon or polypropylene) is placed with bites 2 to 4 mm apart in the periosteum of the anterior orbital rim. Meshwork may be placed both horizontally and vertically. All gauze that has been placed in the orbit should be removed before the final bites are placed.

To avoid postnucleation cysts, excise all palpebral and bulbar conjunctival tissues before closing the lids. Close the lids in three layers. The orbital septum is the connective tissue layer lining the eyelid that originates from the orbital bone, and will move the entire head when pulled. Close the orbital septum within the eyelid (identified mainly by its strength in holding a needle or suture) with 3-0 to 5-0 long-lasting absorbable suture in a horizontal mattress or simple interrupted pattern. Effective closure of the orbital septum is the best way to prevent sinking of the orbit. Close subcutaneous tissues with 3-0 to 5-0 absorbable suture in a simple continuous pattern. Close the skin with 3-0 to 4-0 nylon simple interrupted skin sutures or 4-0 to 5-0 absorbable simple continuous subdermal sutures.

Lateral Enucleation

Advantages of the lateral approach include better visualization of retrobulbar tissues before the globe has been removed, especially in those with deep orbits; improved confinement of the ocular surface from the sterile surgical site; and retention of more orbital tissue than occurs with the transpalpebral technique. Disadvantages compared with the transconjunctival technique include greater loss of orbital tissue and potentially increased bleeding (because much of the dissection occurs more superficially than the subtenon space).

Perform a wide lateral canthotomy using straight, heavy scissors such as a Mayo scissor (Fig. 17-11, A). Bluntly dissect the cut surface of each lid into an anterior skin-orbicularis oculi layer and a posterior tarsoconjunctival layer using a curved Metzenbaum scissor (Fig. 17-11, B). Continue blunt dissection medially until the medial canthus is reached. Remove the scissors, replace one blade of the scissor in the subcutaneous pocket just created, and cut the anterior layer parallel to the lid margin as close to the medial canthus as possible (Fig. 17-11, C). Close the lids with Allis tissue forceps or a 3-0 or 4-0 simple continuous suture with ends left long (Fig. 17-11, D). Use the lateral aspect of the forceps or suture to gently retract and rotate the dissected orbital contents medially, using blunt and sharp dissection of tissues around the lateral globe while clamping and then incising extraocular muscles close to their attachments on the globe (Fig. 17-11, E). Do not pull the globe or place any traction on the eye because this could avulse the optic nerve at the optic chiasm and blind the other eye. Clamp the tissues of the posterior pole of the globe with a hemostat; remove the hemostat and transect the tissues 5 to 10 mm posterior to the globe. Roll the globe out of the orbit from lateral to medial, and transect the remaining extraocular muscles, the medial canthal tendon, and the attachments of the medial canthus to the orbit from posterior to anterior (Fig. 17-11, F). Next, remove the nictitans, and excise any remaining conjunctiva (Fig. 17-11, G).