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quine Eyelid Diseasearyn E. Plummer, DVM

The most common eyelid disorders of horses include traumatic insults, anatomic malalign-ment problems, inflammatory lesions, and neoplasms. These eyelid conditions are dis-cussed in this article with particular attention paid to practical diagnostic and therapeuticoptions. Surgical treatment for eyelid lacerations, entropion, ectropion, and temporarytarsorrhaphies are described. Causes and treatments for blepharitis and neoplastic dis-eases, especially sarcoids, are included.Clin Tech Equine Pract 4:95-105 © 2005 Elsevier Inc. All rights reserved.

KEYWORDS eyelid, laceration, entropion, blepharitis, habronemiasis, sarcoid

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he equine eyelid consists of four major layers: the outer-most typical haired skin, muscle, tarsal plate and stroma,

nd the innermost palpebral conjunctiva. The dorsal andentral folds of skin of each lid are continuous with the facialkin. Underlying subcutaneous tissue is irregular and devoidf fat and blends with the striated orbicularis oculi muscleeep to it. The tarsal plate is an area of dense connectiveissue which lends rigidity to the eyelid margins. A number oflandular structures within the tarsus and at the eyelid mar-in, including the meibomian glands and the glands of Zeisnd Moll, contribute to the preocular tear film or function toubricate the edges of the lids. Stiff tactile vibrissae are presentlong the base of the lower eyelid and at the base of the upperyelid medially. The free edges of the dorsal and ventral lidseet to form the palpebral fissure which should fit close to

he globe except at the medial canthus, where the lacrimalaruncle protrudes. The eyelids function to protect and ex-lude light from the eyes, spread the tear film over and re-ove foreign material from the anterior surface of the globe,

ontribute to the production of the tear film, and facilitate itsrainage through the nasolacrimal apparatus. Evaluation ofhe eyelids should include examination of the cutaneous,arginal, and conjunctival surfaces of both the upper and

ower lids of the patient.Before any sort of sedation, regional nerve blocks, or top-

cal anesthesia, it is important to perform a preliminary ex-mination of the eyelids of the equine patient, paying partic-lar attention to eyelid function, conformation, andeurologic reflexes. Acquiring a detailed history of duration,hanges in appearance, previous therapies, and responses islso crucial as these can guide your diagnostic and treatment

epartment of Small Animal Clinical Sciences, Comparative Ophthalmology,University of Florida, College of Veterinary Medicine, Gainesville, FL.

ddress reprint requests to: Dr. Caryn E. Plummer, Department of SmallAnimal Clinical Sciences, Comparative Ophthalmology, University ofFlorida, College of Veterinary Medicine, PO Box 100126, Gainesville, FL

t32610. E-mail: PlummerC@mail.vetmed.ufl.edu

534-7516/05/$-see front matter © 2005 Elsevier Inc. All rights reserved.oi:10.1053/j.ctep.2005.03.004

lans, as well as your prognosis. The lids should hug thelobe snuggly while being freely mobile, and should be ca-able of performing a complete blink action covering thentire cornea. The shape, position, and condition of the eye-id margins, the relative size of the palpebral fissure com-ared with the globe, the symmetry of the two eyes, and theffectiveness and frequency of the blink response are impor-ant to assess.1 The position of the eyelids may be assessed byonsidering the angle of the cilia (eyelashes) in relation to thelobe. The eyelashes are normally positioned almost perpen-icular to the corneal surface. Cilia which are directed evenubtly downward may indicate lid disease or deformity orhat the patient is experiencing ocular pain or discomfort.

The neurologic reflexes of the eyelids to evaluate includehe menace response, which tests the visual response to atimulus and the eyelids’ ability to respond with movementcranial nerves 2 and 7), and the palpebral and corneal re-exes (cranial nerves 5 and 7). If the menace response isegative, the next step is to assess the palpebral reflex byouching the eyelids or their tactile vibrissae. The afferentathway of the palpebral reflex provides sensory informationhat elicits the blink motor response. In other words, thiseflex helps assess whether the eyelids are capable of move-ent or blinking in response to the visual or sensory stimu-

us.1 The corneal reflex evaluates the sensitivity of the corneaather than that of the eyelid skin and is performed by slightlyouching the cornea with a wisp of cotton. A positive re-ponse is a blink.

raumaraumatic Eyelid Lacerationshe horse often exhibits quick movements of the head inesponse to fear or play situations, with trauma to the eyelidsften a sequela. Any sort of eyelid trauma necessitates a fullphthalmic examination because of the potential for addi-

ional damage to the globe or orbit. Corneal ulcerations,

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lobe perforation, uveitis, periorbital fractures, and orbitalellulitis or abscessation can accompany eyelid trauma. Lac-rations of the eyelids should be repaired promptly to pre-ent lid deformities, infections, and exposure-induced dam-ge to the cornea.2 Depending on the extent of the lid injury,urgery to repair an eyelid laceration may be performed withedation and local anesthesia alone, or for severe lesions withhe animal under general anesthesia.2,3 Akinesia and anesthe-ia of the eyelids can be achieved by injecting 2% lidocaineegionally to affect either motor or sensory innervation of theyelids (Fig. 1). An auriculopalpebral motor nerve block willimit the movement of the lids (specifically the function of therbicularis oculi muscle), and is performed by injecting 1 tomL 1% lidocaine through a 25-gauge, 5/8-inch needle

here the auriculopalpebral branch of the facial nerve is pal-able as it crosses over the dorsal aspect of the zygomaticrch.1,4,5 There are several different sensory blocks that maye employed depending on the location of the eyelid lesion toe addressed. The central two-thirds of the upper eyelid is

nnervated by the frontal or supraorbital nerve, and islocked by injecting 2 mL of 2% lidocaine into the supraor-ital foramen. This foramen can be identified as a small de-ression in the supraorbital process of the frontal bone, me-ial to its most narrow aspect.1,4,5 The lateral upper eyelidnd lateral canthus are innervated by the lacrimal nerve, andan be blocked with a line block along the lateral third of theorsal orbital rim.1,4,5 A block of the zygomatic nerve willnesthetize the lateral lower lid and is achieved with a linelock along the ventrolateral orbital rim.1,4,5 The medial can-hal region is innervated by the infratrochlear nerve and isesensitized by injecting anesthetic through the bony notch

igure 1 Sensory innervation of the eyelids of the horse. These re-ions will be temporarily desensitized by blocking the specificerves as described in the text. A block between the auricolupalpe-ral and palpebral nerves will facilitate examination and repair pro-edures by temporarily limiting motor function of the lids.

n the dorsal rim of the orbit near the medial canthus.1,4,5 F

yelid Laceration Repairt is wise to consider culturing a traumatic eyelid wound ofny long-standing duration before cleaning and suturing theefect. Thorough flushing of the affected area with saline anddilute povidine/iodine (2%) solution followed by minimalebridement of any wound margins or lid pedicles should beerformed. The eyelids have a rich vascular supply and gen-rally do not require removal of tissue of questionable viabil-ty. Even desiccated, avulsed eyelids are capable of recanali-ation by blood vessels following a repair.2 For this reasonnd because of the concern for exposure keratitis, it is imper-tive that eyelid tissue tags and pedicles not be amputated,nd instead replaced to as normal an anatomical position asossible (Fig. 2).

1. It is crucial to accurately appose the lid margin, and thisshould be the first step taken in the repair.2 A figure-eight suture is placed on the eyelid margin that allowsfor knot placement away from the globe (Fig. 3).

2. The remainder of the defect is closed in two layers: adeep layer in the palpebral conjunctiva with 4-0 to 6-0

igure 2 Upper eyelid laceration before repair (A) and after (B).

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Equine eyelid disease 97

absorbable suture material in a simple interrupted orsimple continuous pattern starting at the eyelid margin,and a superficial layer through the skin with 4-0 to 5-0nonabsorbable suture in a simple interrupted pattern(Fig. 4).6-8

ny suture tags that appear capable of irritating the corneahould be incorporated into the knot of the next suture distalo the lid margin. Sutures are usually left in place for 7 to 10ays; however, if there is tension on a repair, the sutureshould remain longer to ensure adequate time for healing.he more extensive wounds and lacerations, especially thoseith tissue loss, are best repaired with the patient undereneral anesthesia and may require sophisticated blepharo-lastic procedures. Lacerations near the medial canthus may

nvolve the nasolacrimal apparatus and affect tear drainage.he integrity of the duct should be tested by close examina-

ion and the passage of fluorescein sodium dye through theasolacrimal duct. If the nasolacrimal canaliculus is dam-ged, surgical repair is definitely warranted.2,8,9 Any lacera-ions of the nictitating membrane should be promptly andarefully repaired as well. Excision of the nictitans shouldnly occur if the damage to this structure is severe or if it isffected by a neoplasm.

Administration of topical and systemic antibiotics, sys-emic analgesia/antiinflammatory drugs, and tetanus toxoidre the mainstays of postoperative medical care. Protection ofhe cornea is absolutely imperative if the lids are swollen orompromised in such a way that the cornea is perpetuallyxposed. Frequent administration of topical artificial tear re-lacement ointment may be sufficient in such cases, whilethers may need a tarsorrhaphy.

emporary Tarsorrhaphytemporary tarsorrhaphy is achieved by placing one or more

depending on whether the tarsorrhaphy is to be partial or

Figure 3 Eyelid laceration repair. (A) The wound is cleanmargin will allow for alignment of the eyelid margin, whperformed if possible. The deep layer should start at theinterrupted skin sutures finish the closure.

sed and minimally debrided. (B) A figure-8 suture at the eyelidich is critical to an effective repair. (C) A two-layer closure iseyelid margin as well and proceed distally from it. (D) Simple

omplete) horizontal mattress sutures of 3-0 to 5-0 nonab- F

igure 4 Lower eyelid laceration before repair (A) and after (B).

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orbable material partial thickness along the eyelid margin toistribute tension and avoid contact with the cornea (Fig. 5).he use of stents (rubber bands, IV tubing, buttons) is advis-ble to prevent the suture from cutting into the eyelid. Theedial canthus is usually left open to facilitate drainage andedication administration. While the wound is healing, it is

mportant to prevent further damage (usually self-inflicted)o the repair site. A hard-cup hood or thick head bumper maye necessary to prevent rubbing of the area. Fly masks areften critical to keep the wound free of unwanted visitorsuring the healing process. Alternatively, a fly repellant oint-ent may be applied adjacent to the surgical site.

lunt Trauma-Induced Blepharitislunt trauma may not necessarily result in an actual lacera-ion, but may alternatively result in blepharoedema and he-atomas of the eyelids due to the lack of dermal fatty tissue

n this region. Lid swelling is treated with ice-packing andystemic antiinflammatory drugs, such as flunixin meglu-ine. Again, if eyelid function is impaired, measures must be

aken to protect the cornea. Small eyelid punctures mayause an infectious blepharitis or eyelid abscesses or celluli-is.9 Eyelid abscesses are addressed by first obtaining samplesf exudates for culture and sensitivity and then administeringystemic antibiotics and antiinflammatories. Cytologic exam-nation and Gram stain of samples from the affected area mayuide empiric therapy while culture results are pending.arm compresses are usually helpful. Some wounds will

equire surgical debridement or the placement of drains. For-ign bodies are another source of traumatic insult. Any pa-ient presenting for epiphora, conjunctivitis/chemosis,lepharitis/blepharospasm, or corneal damage (especially re-urrent or refractory lesions) should have a thorough searchor foreign objects, paying particular attention to the con-unctival fornix and the area posterior to the nictitating mem-rane. Removal of a foreign body and appropriate supportiveare should be instituted when a foreign body is discovered.ven seemingly minor traumatic insults can result in cicatri-ial entropion and ectropion that may need surgical atten-ion. It is important to be vigilant and inform owners of this

Figure 5 Temporary tarsorrhaphy. (A) All of the horizontal many one individual suture. (B) It is important to make the sutucornea. Sutures should exit at the level of the meibomian glansutures are tied.

ossibility.

ntropion andther Anatomicalalalignment Problems

ntropion is the inward rolling of the eyelid margin, whichay allow eyelid hair to contact and irritate the cornea. Clin-

cal signs include excessive tearing and blepharospasm, andariable amounts of keratitis and conjunctivitis. Entropion isost often seen in young foals, and may be either hereditary

r acquired (Fig. 6). Since many cases of foal entropion areecondary to ocular irritation, systemic diseases (especiallyhose resulting in dehydration or loss of periorbital tissue orat), or disproportionate growth and since the growing foalas a dynamic conformation, surgical correction is not rec-mmended until maturity is reached. In the meantime, ocu-ar lubricants and sometimes temporary eversion of the of-ending eyelid with vertical mattress sutures or staples maye necessary. Entropion may also be from spasms of therbicularis oculi muscle due to chronic, irreversible ocularrritation, or may be cicatricial due to previous eyelid traumascarring). If surgical therapy is indicated, it is absolutelyritical that the extent of required correction be determinedith the animal awake. Topical anesthetics and a local nervelock will facilitate differentiation between any primarynatomic component of the entropion and any secondaryontribution of spasm. The goal of surgical correction of en-ropion should be slight undercorrection because over-orrection can cause problems more significant than the ini-ial complaint.

odified Hotz-Celsus Procedure1. The modified Hotz-Celsus procedure is particularly

useful for dealing with most entropion conditions inthe adult horse.2,8 This procedure should not be donein foals. The procedure is simple and involves remov-ing a crescent-shaped piece of skin and orbicularismuscle (Fig. 7).8,10 The initial incision is made with aNo. 15 scalpel blade 2 mm from the eyelid margin, itslength dependent on the amount of eyelid margin in-

utures that are to be employed are preplaced before securingh only partial thickness to prevent damage to the underlyingings. (C) Stents reduce tension on the eyelid tissue once the

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Equine eyelid disease 99

2. A second elliptical incision made parallel to the firstjoins the two ends of the first incision.

3. A Jaeger lid plate inserted into the conjunctival fornixwill stabilize the skin for these incisions. The width ofthe piece of tissue to be excised will have been previ-

Figure 6 Lower ey

Figure 7 Modified Hotz-Celsus procedure for treatment omuscle is incised with a Bard-Parker No.15 scalpel bladewound is closed in one layer. The first suture should b

nonabsorbable sutures are used in the repair and are left in pla

ously determined while examining the awake horse forthe amount of eversion necessary for a correction.

4. After the skin is incised to the depth of the orbicularisoculi muscle, the skin and a portion of this muscle areundermined and excised with scissors.

tropion in a foal.

pion. (A) An elliptical strip of skin and orbicularis oculien carefully elevated and excised with scissors. (B) Theed in the center of the defect. (C) Simple interrupted

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5. The defect is then closed using 4-0 to 6-0 nonabsorb-able suture material in a simple interrupted pattern.The first suture placed should be the central suture,which will separate the wound into two equal halves.This insures even closure.

6. The suture ends adjacent to the cornea are trimmedshort to avoid irritation of the cornea. The sutures areleft in place for 10 to 14 days.

-to-V Entropion Repairn cases in which a focal lesion, usually a cicatrix, is the causef the entropion, a Y-to-V repair may be advantageous (Fig.).8

1. In this procedure, a Y-shaped incision is made such thatthe arms of the Y span the length of the offending le-sion. The height is determined by the extent of theeversion necessary.

2. The skin is undermined and the cicatricial tissue isdissected free with scissors.

3. The central point of the Y is then sutured to the distal

Figure 8 Y-to-V entropion repair. (A) The arms of the Ycicatricial lesion. (B) Once the incision is made with a sceyelid margin is everted when the V-shaped flap thatV-shaped final closure.

Figure 9 V-to-Y ectropion repair. (A) The arms of the V-(B) Once the incision is made, the resulting skin flap is elflap to be advanced toward the eyelid margin, relieving t

(C) To keep the eyelid margin in its proper position, the woun

base of the Y ultimately resulting in a V-shaped skinclosure.

4. Simple interrupted sutures of 4-0 to 6-0 nonabsorablematerial are utilized here as well.6,10,11

ctropion and the V-to-Y Repairctropion is an outward rolling of the eyelid margin and,hen present in the horse, is most frequently a consequencef cicatrix formation involving the eyelid or periorbital re-ion. The increased exposure of the conjunctiva and corneand the potential problems resulting from that are whatakes it necessary to correct an ectropion. The favored repair

s the reverse of the focal repair for entropion. In the case ofctropion, a V-to-Y plasty procedure is performed (Fig. 9).8

1. A V-shaped skin incision is made to encompass theextent of the affected area.

2. Its skin flap is undermined and the underlying scartissue is excised.

3. The flap is then advanced toward the eyelid margin and

incision will extend slightly beyond the extent of thethe scar tissue should be excised with scissors. (C) Theis sutured into the Y-shaped incision, resulting in a

incision will again encompass the extent of the lesion.and scar tissue is excised. This should allow for the skinand returning the eyelid margin to its normal position.

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Equine eyelid disease 101

closed so that the tension on the lid is relieved and aY-shaped closure results.6,8,10

lepharitislepharitis can be the result of a traumatic event, an infec-ious agent, an immune-mediated process, or a neoplasmFig. 10). Cytology and culture, and potentially skin scrap-ng, of any persistently inflamed eyelid is recommended.

hile primary bacterial blepharitis is rare in the horse, sec-ndary infections due to a wound, foreign body, or even aubpalpebral lavage system are not uncommon. Removal ofhe foreign body if indicated, wound cleansing, hot-packing,nd systemic antibiotics are the preferred treatment regime.ermatophytes such as Trichophyton or Microsporum spp cane responsible for blepharitis as well, either primarily or sec-ndarily.2,12 Topical administration of miconazole 2% oint-ent is usually sufficient for dermatophytosis unless theorse has a generalized immune-suppressive condition.2,12

ther more aggressive fungal infections have been reportedo cause blepharitis in the horse, and these usually requireystemic administration of antifungal agents.

Immune responses that may result in blepharitis includellergic reactions, both acute and chronic, drug reactions,osinophilic granulomas, solar irritation, and the pemphi-oid diseases. Biopsy and histopathologic examination wille essential for these diagnoses and treatment will be aimedt modulating the immune response. Tumors with aggressive

Figure 10 Brush-fire induc

nflammatory components such as squamous cell carcinomas o

ay manifest as blepharitis. Lymphoma has been associatedith lid and conjunctival swelling.14

arasitic Blepharitisrobably one of the most common causes of blepharitis in theorse is local infection with a parasitic organism. Habronemarganisms are common residents of the equine stomach. Lar-al habronema stages (specifically the infective L3) passed inhe horse’s feces and ingested by an intermediate host (usu-lly a house or stable fly) can be deposited in wounds or ondnexal structures.2,8,11 Nodular or ulcerative periocularranulomas and fistulous tracts with a gritty, yellow exudatef necrotic mineralized tissue can be found with habronemi-sis.8,11 The medial canthus is the most frequent site of inva-ion, but habronemiasis can affect any portion of the eyelids,onjunctiva, nasolacrimal apparatus, or nictitating mem-rane (Fig. 11). Signs are most common in the summeronths. Much of the inflammatory response is due to an

mmune-mediated hypersensitivity to the offending organ-sm.2 Eosinophils and mast cells abound in cytologic samplesf these lesions. Treatment involves removing or destroyinghe organisms, alleviating the inflammation, and eliminatingny secondary infections present. Fly control is crucial. Mul-ifocal lesions can most easily be treated with systemic ad-inistration of ivermectin (200 g/kg PO or 0.02 mg/kg IM)

nd topical use of an antibiotic-corticosteroid ointment (asong as no corneal ulceration is present).2,8 A mixture of 135 g

haritis in an adult horse.

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DMSO), 30 mL of 0.2% dexamethasone, and 30 mL of2.3% oral trichlorfon has been suggested for topical use onolitary lesions.8 Alternatively, oral diethylcarbamazine (6g/kg for 21 days) may be effective.8 Surgical removal of

ranulomatous lesions may hasten recovery, but care must beaken to preserve sufficient eyelid tissue for proper func-ioning of the lids. Intralesional corticosteroids, such asriamcinolone, may help reduce the size of the granulomasy helping to control the hypersensitivity reaction to therganism.2 Other organisms to keep on the differential listnclude the normally commensual nematode Thelazia,hich can cause mild lid swelling and dacryocystitis, De-odex, which can cause meibomianitis, alopecia, and der-atitis, and Onchocerca. 11

eoplasiahe most common eyelid tumor in the horse by far is squa-ous cell carcinoma, which will be addressed fully in a sep-

rate chapter of this publication. Sarcoids are the next mostrequent tumor of the periocular region of the horse. Numer-us other tumor types are of low incidence and include fibro-as, fibrosarcomas, schwannomas, basal cell carcinomas,

ymphomas, adenocarcinomas, hemangiosacromas, plasma-ytomas, mast cell tumors, papillomas, and melanomas.13

mong the more rare neoplasms, papillomas are observed inelatively immature animals and are the result of the body’seaction to a papovavirus.12 Most papillomas are self-limitingnd regress spontaneously, but an occasional persistent le-ion may require surgical removal, cryotherapy, or autoge-

Figure 11 A lesion typi

ous vaccination. Melanomas also warrant note because of v

heir propensity to occur in gray-colored animals. Arabiansnd Percherons may also have an increased risk for melano-as.2 Treatment for these tumors is surgical excision fol-

owed by cryotherapy. Since the different kinds of tumorsave different behaviors and prognoses, it is important tobtain a definitive diagnosis with either fine-needle-aspiratend cytology or, preferably, with histopathology. Also, notnfrequently will inflammatory lesions masquerade as neo-lasms (eg, Habronemiasis granulomas), which is anothertrong argument in favor of performing a histopathologicxamination.

arcoidsarcoids are the most common cutaneous tumors and theecond most frequently recognized periocular tumors inorses. They generally have a low metastatic potential, butre frequently locally invasive. Sarcoids are fibroblastic neo-lasms that are sometimes a challenge to diagnose and treat,articularly when they appear in the periocular region be-ause they can be unpredictable in their behavior and re-ponses. They occur in several clinical forms ranging fromreas of alopecia or altered character of the hair alone (occult)o alopecia with thickening, hyperkeratosis, flaking, andometimes skin ulceration (verrucuous) to nodular with vari-ble overlying skin involvement (nodular) (Fig. 12) to a firm,roliferative, fleshy mass with ulceration (fibroblastic) (Table).15,16 Intermediate and mixed forms also exist, as do sub-ypes within each form. Unfortunately, the clinical appear-nce is not reliable in determining future behavior and the

yelid habronemiasis.

arious types may transform over time. Some sarcoids are

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Equine eyelid disease 103

xtremely aggressive and resistant or refractory to treatment,hile others regress spontaneously. While they do not me-

astasize, they can be locally aggressive and tend to have aelatively high rate of recurrence, especially when surgicalethods of treatment leave residual tumor cells in place. Theean age for the onset of clinical signs associated with sar-

oids is between 3 and 7 years of age.18 Quarter Horses,ppaloosas, Arabians, and Thoroughbreds are reported toave the highest risk, while Standardbreds and Lippizanersave the lowest.17 It is believed that genetic predisposition, asell as the potential induction or influence of a viral agent

bovine papillomavirus types 1 and 2 have been implicated),ay play a role in the development of these tumors.17,19 The

resence of flies is considered a risk factor for the develop-ent of sarcoid because flies are believed to be capable ofirectly translocating sarcoid cells to open wounds or to theedial canthal region of horses.17 Diagnosis depends on an

ndex of clinical suspicion and biopsy results. Since biopsy orurgical trauma (or any trauma at all for that matter) maynduce proliferation and expression of virus and resultant

igure 12 A nodular sarcoid on the upper eyelid of a horse.

able 1 Types of Sarcoids

Type of Sarcoid

ccult Area of alopecia orerrucose Alopecic, thickenedodular Type A Subcutaneous noduodular Type B Subcutaneous noduibroblastic Type A Fleshy, ulcerated aibroblastic Type B Fleshy, ulcerated aixed Characteristics of talignant Unusual; aggressiv

variable ulceration

umor cells, it is important to undertake this procedure withplan for prompt subsequent treatment and only after warn-

ng the owner that the tumor may grow rapidly and aggres-ively after the biopsy is taken.19 Differential diagnoses forarcoid include fungal dermatitis, dermatophilus, granula-ion tissue, granulomas including habronemiasis or on-hocerciasis and foreign body reactions, papillomas, melano-as, squamous cell carcinomas or other neoplastic lesions,

nd scarring, depending on the clinical appearance.16,18

Treatment for these tumors can be performed with severalifferent modalities, but the goal of therapy is to remove asuch, if not all, of the tumor as possible, either by physical orechanical surgical removal, by immunologic destruction,

r by a combination thereof. Options include benign neglect,urgical excision with wide margins (at least 1-2 cm of nor-al tissue is ideal), cryotherapy, chemotherapy, immuno-

herapy, and radiation therapy (Tables 2 & 3).2,8,15,16,18 Manyf the treatment methods performed elsewhere on the bodyre impossible or impractical for periocular sarcoids. Surgicalxcision alone (either conventionally or if performed by laserblation) has a recurrence rate of as high or higher than 50%,ue at least in part to the difficulty of excising all affectedissue without compromise to lid and adnexal function in theorse.8,15,16 Combination therapy is therefore commonly em-loyed, particularly with large lesions, where debulking iserformed, followed by some other modality, such as immu-otherapy with BCG or cryotherapy, especially if histologicvaluation suggests incomplete resection. Ancillary treat-ents could include any of the above-mentioned treatment

ptions. Cryotherapy alone can be effective for smaller le-ions and has success rates of up to 75%.8,21 It is relativelyasy, quick, and inexpensive to perform and can be repeated,ut when unsuccessful in achieving remission frequently re-ults in the proliferation of the aggressive fibroblastic formhat may be refractory to treatment (Fig. 13).15 Intralesionalhemotherapy with either cisplatin (1 mg/cm3 of 3.33g/mL solution once every 2 weeks for 4-5 treatments), an

lkylating agent that binds to DNA and inhibits replication,r 5-fluoruracil (50 mg/mL in a 1:1 ratio of oil every 1-2eeks for 4-5 treatments), an antimetabolite, in sesame oilave had variable successes of up to 80%.2,18,22 Cisplatin isuch more expensive than 5-FU, but it may also be more

ffective. These two intralesional drugs may be appropriatehen other modalities of treatment are not possible. Proba-ly the most promising methods of treatment are immuno-herapy, especially in conjunction with surgical excision, andadiation therapy. Radiation therapy is very expensive, but

Description

d hair, small sub-epidermal, miliary nodules/plaqueswith hyperkeratosis and extensive flaking, some ulcerationh no epidermal involvementh varying involvement of overlying skinnce; pedunculated, limited base palpable within skinnce; broad-base, with thickening beyond obvious marginsmore of the other defined typesles, cords of palpable tumor, extensive infiltration,

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as the best outcomes with long-term success rates ap-roaching 100%.15,16,20 Interstitial brachytherapy (gammaadiation) with iridium-192 or gold-198, wherein radioactivemplants are placed within the offending masses and left for0 to 14 days, delivers a large dose of radiation to a focal areaith little affect on surrounding tissues. It has limited avail-

bility in private practice, however, and is restricted to certi-ed operators and approved facilities. Beta radiation withtrontium-90 is less effective in large masses because its pen-tration is limited to 1 to 2 mm.15,16 Immunotherapy withacillus Calmette-Guerin cell wall extracts stimulates a non-pecific immune response that can result in regression ofarcoids. It is most effective for the nodular (Fig. 12) andbroblastic forms of sarcoid (Fig. 13); occult and verrucuousorms tend to respond poorly.15 Therapy consists of intrale-ional (rather than perilesional) injection of the product tohe point of saturation of the tumor (usually 1 mL/cm3).2,16

he procedure is repeated every 2 to 4 weeks for 3 to 9reatments in the same location.16,23 It is very important to

able 2 Sarcoid Treatment Regimes

Agent

ryotherapy Three quick freisplatin 3.33 mg/mL 1 mg/cm3

-FU 50 mg/mL in 1:1 sesame oil 1 mL/cm3

CG 1 mL/cm3

able 3 Sarcoid Therapy

TreatmentModality

Overall SuccessRate

Typ

enign neglect Variable All typesurgical excision <50% Extensivryotherapy Up to 75% Large orhemotherapy Up to 80% Occult, v

mmunotherapy (BCG) 69–100% Occult, vadiation Nearly 100%

igure 13 An ulcerated fibroblastic sarcoid (the most aggressive

orm) on the upper eyelid of a horse.

ote that as a consequence of the immune reaction that isenerated by the BCG, each subsequent injection carries witht the likelihood of a faster and more intense local inflamma-ory response, and the possibility of anaphylaxis (rare butossible).23 For these reasons, it is recommended that theatient be prophylactically pretreated with flunixin meglu-ine (1.1 mg/kg IV) and diphenhydramine HCL (1.0 mg/kg

V) before administration of BCG.2,8,15,16,18 With each addi-ional injection, more local inflammation should be presentnd progress to the point where necrosis, ulceration, andegression are usually evident after the third injection. Thenflammation should be allowed to subside before additionalnjections are performed.8 Treatment is discontinued if noesponse is seen after the fourth injection.18 Tumor regres-ion may occur slowly over several months. For the nodularnd fibroblastic forms of sarcoid, success rates of immuno-odulating therapy with BCG range from 69% to 100% (Ta-

le 3).15,16,17,24 Other forms of treatment including hyper-hermia and topical application of 5-fluoruracil ordoxuridine have been attempted with only marginal to pooruccesses.8,15 The overall prognosis for equine periocular sar-oids is guarded. Cases that carry the worst prognosis arehose that have been previously treated unsuccessfully.15

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8. Miller TR: Eyelids, in Auer JA (ed): Equine Surgery. Philadelphia, PA,

Frequency

ow thaw cycles May be repeatedQ 2 weeks � 4–5 treatmentsQ 1–2 weeks � 4–5 treatmentsQ 2–4 weeks � 3–9 treatments

at are Non-responsive to or Unsuitable for thisTherapy

tually need treatment of some form or euthanasians, achievable margins <2 cm, without adjunctive therapylesionsoseose

Dose

eze/sl

es th

evene lesiodeeperrucerruc

WB Saunders, 1992, pp 599-619

1

1

1

1

1

1

1

1

1

1

2

2

2

2

2

Equine eyelid disease 105

9. Brooks DE: Ocular emergencies and trauma, in Auer JA (ed): EquineSurgery. Philadelphia, PA, WB Saunders, 1992, pp 666-672

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