1 The eyeball,Conjunctiva and corneaProf.Dr.Gamal Karrouf

2 The eyelids The eyelids are two folds of skin that shield the eyeball. The upper lid is larger and more movable. It regulates the opening and closing of the eye with the help of the orbicularis palpebrarum muscle. Lower-lid movement is slight. The eyelids sweep dirt from the surface of the eye, protect it from injury, and help distribute the tear fluid . The eyelids are thin and contain many blood vessels. Eyelids protect the eye, produce and distribute the tears, aid tear drainage, and help control the amount of light entering the eye.

3 Meibomian glands (tarsal glands),are found at the inner eyelid margins which secrete the fatty viscid component of the tear film that prevent outflow of lacrimal secretions and lubricates the eye, Nictitans--The nictitans or third eyelid (TE) of the horse is located medially (toward the midline of the body; the medial edge of the eye is the one toward the nose) and contains the third eyelid gland that produces tears. It has supportive cartilage and a covering of conjunctiva

4 The lachrymal apparatuscomposed of, firstly, the lachrymal gland, which lies in a depression of the orbital arch dorsolateral to the eyeball; secondly, of the lachrymal canals, by which the tears are poured out upon the conjunctiva a little above the border of the upper lid; thirdly, the lachrymal ducts, which are destined to receive the tears after they have bathed the eye, fourthly, the lachrymal sac, in which the lachrymal ducts terminate, and which empties the tears into the nasal canal.

5 The lachrymal apparatusFrom the medial angle by 4-5 mm and on the conjuunctival surface of each lid margin there are 2 small slit like opening (punta lacrimalis) through which lacrimal fluid drain into superior and inferior canaliculi to lachrymal sac to nasolacrimal duct to nasal cavity and of which the orifices or lachrymal points are seen near the internal commissure of the lids;

6 Lacrimal Anatomy Lacrimal gland Lacrimal ducts Puncta CanaliculiLacrimal sac Lacrimal duct Exit to nose or mouth

7 Anatomy of a Tear 3 layers within tear film Function:Mucous layer – Goblet cells Aqueous layer – Lacrimal gland and gland of the 3rd eyelid Lipid layer – Meibomian glands Function: Lubrication, nourishment, immune competency, cleansing, optical clarity

8 Congenital Diseases Dermoids Misplaced skinUsually on the cornea, but may involve the conjunctival surfaces

9 Dermoid cyst Typical cutaneous growth with long hair, lying in different directions, mostly present at the lateral canthus. May be pigmented or non-pigmented. Unilateral or bilateral. Single or multiple. May extend up to conjunctiva and/or cornea.

11 Treatment of Dermoid cyst: Surgical.· Appropriate anesthetic technique (GA/sedation with regional anaesthesia). · Complete asepsis. · Dermoid is excised along with healthy tissue and wound is closed using non absorbable suture material (1-0 or 2-0) applying simple interrupted sutures · Postoperatively use topical antibiotic ointments with corticosteroids for 6-8 days. Uses of ointments prevent adhesions.

13 Eyelids Ectropion Trauma DistichiaCongenital rare: reported in Piebald sheep Developmental, cicatricial, trauma, postoperative Surgical repair if conjunctivitis, keratitis, epiphora present Trauma Lacerations are infrequent Surgical repair indicated in most cases Distichia May be inherited in cattle

14 Allergic Blepharitis Acute blepharo-edema and chemosisOften bilaterally symmetrical Topical or systemic anti-inflammatory and antihistamine medications

15 Blepharitis It is the inflammation of the eyelids. It is a form of dermatitis which is either superficial or deep. The superficial one is a type of eczema, while the deep one is a result of phlegmone.

17 Blepharitis Cytology Bacterial and Fungal CultureBiopsy – full thickness (V-resection) Treat as any other skin disease Icthyol ointment 5% can be applied on the periphery of the eye, while an antibiotic ointment is applied inside the eye.

18 Blepharoptosis (Ptosis)It is the drooping of the upper eyelid as a result of swelling of the lid or section of its tendon, but the main cause is paralysis of the levator palpebrae which may be more or less complete. Treatment: Ptosis resulting from paralysis is difficult to treat. The best interference is the partial excision of the drooped eyelid in order to expose the eyeball. Other cases caused by swelling, the cause must be removed

19 Eyelid Neoplasia Take narrow margins in initial biopsiesAlways submit tissues for histopathology ¼ -1/3 of the eyelid margin can be removed V or House eyelid resection

20 Traumatic Injuries of the eye-lidsTraumatic injuries of the eye-lids are mostly contusions and open wounds. The later are the most serious and may occur either perpendicularly or parallel to its free border. The eyelid may completely torn away. Wounds may be caused by falls, or blows or catching in hooks or nails or by bites. Treatment: goes on general principles, but particularly important point here is to conserve as much tissue as possible. The wound should be aseptically and carefully sutured if practicable. Primary healing frequently occurs. when the borders of the wound are brought in an accurate apposition to each other. An ophthalmic antibiotic ointment should be locally applied 2-3 times daily for 7-10 days.

21 Lacerations Primary repair without debridement of tissue due to excellent blood supply

22 Chalazion Lipid granuloma resulting from a ruptured Meibomian glandYellowish bulge in margin of palpebral conjunctiva Debridement is curative

23 Eyelid Neoplasia Very common in the dog Generally benign in the dogMeibomian adenoma and papillomas are the most common Melanoma, Squamous cell carcinoma, fibrosarcomas, and sebaceous adenocarcinomas are also common

24 Eyelid neoplasia Eyelid tumors are common in dogs. Tarsal glands adenomas are the most frequently diagnosed, less commonly found are adeno-carcinoma, melanomas and papillomas. In horse a number of eyelid tumor type have been reported including squamous cell carcinoma, equine sarcoids, fibromas, melanoma, basal cell carcinoma, papilloma, lymphosarcoma, hemangiosarcoma and adeno-carcinoma. Of these neoplasms, squamous cell carcinoma is by far the most common tumor followed by sarcoids. All other tumor types are rare. Papillomas, are fairly common tumours of the eyelid and periocular tissues in young animals and usually regress spontaneously over a period of months so that no treatment is required.

25 Sarcoids are non malignant locally invasive fibroblastic cutaneous neoplasm peculiar to equidae. They begin as a small wart like growth but may be progress to reach the size of tennis ball. Generally, they are of dry-scaly masses that may be ulcerate and bleed . Sacroids are considered to be the most common skin tumor in equine. They tend to be locally invasive but they do not metastasize. Diagnosis of sacroids usually depends on a combination of clinical suspicion and biopsy.

26 15 cases of equine sacroids were recorded in the present study15 cases of equine sacroids were recorded in the present study. They affect mainly young animals of both sexes. The neoplastic swellings were restricted to ear, mouth commisure and periocular region. The later was mostly unilateral and affect the upper eyelid

28 Treatment 1-For adenomas surgical excision is usually curative . Cryosurgery using liquid nitrogen at 20 degree can also be used. 2-For squamous cell carcinoma and sarcoid Suitable cases can be treated by complete or partial surgical excision according to the location and extent of the tumor. Cryotherapy. A double freeze thaw cycle using liquid nitrogen is the treatment of choice. c) Radiotherapy. Refer to a specialist centre d) For periocular sarcoids, the treatment of choice is immunotherapy using intralesional administration of various compounds including autogenous bacterins, sarcoid vaccine, live Bacille Calmette-Guerin (BCG).

29 The eye-ball: congenital abnormalitiesAnophthalmos: it is a rare condition and in general indicates absence of eyeball. However, the orbit may contain fibro-fatty tissue. It is usually associated with other congenital defects and may be unilateral or bilateral. Microphthalmos: it is a small imperfectly formed eye resulting from underdevelopment leading to small size of the globe. The eye looks smaller and may be cystic. Cyclopia: it is the presence of one eye only located on the middle of the head.

32 Cyclopia was recorded in a buffalo calf which was died shortly after parturition. Postmortum examination revealed the presence of only one eye located on the middle of the head

34 congenital abnormalitiesEndophthalmos: it is sinking of the eye ball in the orbital cavity and usually occurs along with microphthalmos. Exophthalmos: it is abnormal protrusion of the globe. Retrobulbar Lympho-sarcoma is the most common cause in cattle, although post-traumatic orbital inflammation, orbital cellulites and sinus expansion due to chronic sinusitis or tumor may also be considered. Nanophthalmia: the term refers to the restricted development of the eye in all dimensions. The eye is smaller in size but otherwise normal.

35 Conjunctiva Anatomical considerationThe conjunctiva is mobile richly vascularized ocular mucous membrane and lines the inner surface of the eyelids (palpebral coniunctiva), outer part of the eyeball (bulbar conjunctive) and the inner and outer surfaces of the third eyelid. The third eyelid, called membrana nictitans, is present at the medial canthus of the eye and is a mobile protective physical and immunological barrier. The conjunctival mucosa allows smooth, friction-free movements between the globe, the third eyelid and the eyelids.

36 Conjunctiva and corneaSince the conjunctiva is continuous with the corneal epithelium and skin, disease can spread from conjunctiva to the cornea and vice versa. However, the entry of pathogens through the conjunctiva is limited by leucocytes in the conjunctiva and antibodies secreted in the tear film.

37 Affections: 1. Chemosis: · Edema of conjunctiva.· Occurs due to local or systemic allergic reaction. · Inflammation due to infection or trauma. · Treated locally using topical corticosteroids. · Cold application is useful.

38 Dermoid cyst: · Congenital cutaneous growth on the conjunctiva.· Dark brown to black in color. · Has number of hair follicles. Treatment: § Surgical excision of the Dermoid is done under general anaesthesia. § Suturing of conjunctiva is not required. However if required, simple continuous suturing is done using 4- 0 or 5-0 chromic catgut/Vicryl. § Topical antibiotics with corticosteroids for 5-7 days postoperatively.

39 Conjunctivitis Aetiologya) Primary conjunctivitis: local irritants, allergies, toxins chemicals, parasites (onchocerciasis), bacteria Moraxella species) and mycoses e.g. blastomycosis b) Secondary to other ocular diseases such as eyelid problems, disorders of the lacrimal system and keratitis. c) Conjunctivitis is also a non-specific features of a number of systemic diseases, most notably respiratory viral infections (e.g. equine influenza, equine viral arteritis, adenovirus infections in foals, infectious bovine rhinotracheitis, blue tongue)

40 Inflammation of conjunctiva leads to many changes in the conjunctiva· Active hyperemia: Seen in response to any type of the external stimuli. · Papillary hypertrophy: Thickening of conjunctiva and increased vascularity gives conjunctiva a less transparent velvety appearance. · Increased Tear production: Inflammation causes stimulation of goblet cells present in the conjunctival epithelium and there is increased mucous production with proliferation of more goblet cells. · Proliferation of lymphoid follicles: Lymphoid follicles are normally present on the bulbar surface of third eyelid but following conjunctivitis these proliferate and are seen on the palpebral surface also. Increased leukocytic proliferation: Neutrophilic proliferation is commonly seen following bacterial conjunctivitis.

41 Clinical Signs Chemosis: · Edema of conjunctiva.1) The eye is often uncomfortable. 2) Ocular discharge which may be serous, mucoid, purulent or combination of these; occasionally, there is a hemorrhagic discharge. 3) The conjunctiva is reddened (pink eye) because of active hyperemia of the conjunctival vessels. 4) Chemosis (conjunctival oedema) is usually present. Chemosis: · Edema of conjunctiva. · Occurs due to local or systemic allergic reaction. · Inflammation due to infection or trauma. · Treated locally using topical corticosteroids. · Cold application is useful.

42 5) In some cases, granulomatous inflammation and follicle formation may occur as a feature of chronicity. The follicles are particularly obvious when they occur at the limbus and in the region of the third eyelid

43 Treatment a)Treatment of conjunctivitis depends upon establishing and eliminating the cause b) In simple conjunctivitis not associated with systemic disease, subconjunctival injections of steroids and antibiotics provide satisfactory result in most cases. c) In the early cases topical instillation of steroid antibiotic combination is also useful. d) In normal eyes Gram positive organism predominates, whereas in animals with any type of ocular surface disease, G-ve organisms can be cultured with greater frequency. Chlorm-phenicol is probably the most useful topical antibiotic when G +ve organisms predominate and gentamicin is effective against G-ve organisms.

44 e) In mycotic conjunctivitis treatment may be required for weeks or months. Topical clotrimazole and miconazole have been used. corticosteroids by any route are contraindicated in the management of fungal corneal infections Topical treatment is usually maintained until good clinical healing has occurred; usually this take a minimum of weeks. f) In conjunctivitis due to systemic disease, specific treatment is not necessary as most cases recover spontaneously within 14 to 21 days; however the ocular discharge should be cleaned daily and broad spectrum antibiotics are instilled in the eyes to check secondary infection.

45 Pterygium A condition characterised by thickening of the conjunctiva and its blood vessels. Such thickening encroaches on the cornea in the from of a triangular process with its apex towards the centre of the cornea. Treatment: when the encroachment does not reach the pupil, it is not harmful and can not be interfered. When it reaches the pupil, it must be removed by a special knife under the influence of local anaesthesia.

46 Pterygium: § Degenerative condition of conjunctiva characterized by presence of flat triangular prominence on the conjunctiva due to chronic irritation. § Heavily vascularized. § Interferes with eyeball movement. Treatment: § Surgical excision is done under general anaesthesia. § Conjunctival wound is closed applying simple continuous pattern using 4-0 0r 5-0 chromic catgut. § Postoperative antibiotics with corticosteroids.

47 Conjunctival Burns · Mostly develops due to hot liquids, acids or alkali. · Most common etiological factor is lime particle. · Acid burns are generally superficial due precipitation of the protein layer. · Alkali burns are deep as alkali dissolves the protein layer. Such burns mostly lead to the development of symblepharon affecting the movement of eyelid movements. Treatment: § Flushing of affected eye is done to remove the lime particles. § Neutralization of lime particles can be done using 5% ammonium carbonate. § Repeat flushing with NSS. § Topical antibiotics with corticosteroids for 8-10 days. § Topical anaesthesia can be used to take care of pain.

48 Neoplasm: § Less common than neoplasms of lid or skin.§ Most common is squamous cell carcinoma. § Mostly seen in horses and cattle, rare in dogs. § Other less common tumors are haemangioma, haemangiosarcoma and melanocytoma. § Tumors have been reported to develop from solar irradiations. Treatment: § Surgical excision under general anaesthesia or regional block as per the animal. § Close the conjunctival wounds using 4-0 or 5-0 chromic catgut. § If metastatic removal of whole eye is recommended. § Postoperative antibiotics with corticosteroids.

49 Conjunctival neoplasiaSquamous cell carcinoma of the palpebral and bulbar conjunctiva are especially common in equine and cattle. The mean age of occurrence is 8–10 years. The tumor often involves other ocular structures in the horse particularly the nictitaing membrane, corneosclera, eyelids and nictitating membrane. In dogs hemangiomas and hemangiosarcomas are among the more common, the anterior surface of the third eyelid and bulbar conjunctiva are the usual sites for these vascular tumors. Ocular squamous cell tumors which often involve the eyelid and conjunctiva occur more frequently in cats than dogs

50 Clinical signs and diagnosis1. Squamous cell carcinoma of the conjunctiva present initially as an area of conjunctively hyperemia that may ulcerate or progress to become a pink slightly raised and roughened area of the conjunctiva. 2. The tumor may have a papillomatous (cauliflower–like masses ) appearance or, if untreated, become unsightly granulomatous appearing mass. 3. Affected eye usually have associated conjunctivitis and ocular discharge.

51 Clinical signs and diagnosis4. Squamous cell carcinoma may involve both palpebral conjunctiva and the eyelids or bulbar conjunctiva and cornea. 5. Local invasion of ocular and periocular tissues occur and may imvolve the globe, the bony orbit, paranasal sinus and brain . 6. Metastasis occur to regional lymph nodes, parotid L.Ns and L.Ns of the cervical chain and mediastinum.

52 Diagnosis All lesions suspected as being squamous cell carcinoma should undergo biopsy for histopathology. The tumor as often quite friable and impression smears may be used for an early diagnosis. Differential diagnosis Conjunctival neoplasia should be differentiated from conjunctivitis (common) and conjunctival amyloidosis (rare) by clinical appearance and histopathology

53 Treatment a)Surgical excisionSmall areas of conjunctival tumor can be excised by using a scalpel and or electrocautery. Care should be taken to excise as wide a margin as possible (at least 3mm). Adjacent conjunctiva is used to close the defect and is apposed by simple interrupted 2-0 chromic catgut sutures. Small conjunctival defects can close by secondary intention b) Cryotherapy. Cryotherapy can be used for conjunctival squamous cell carcinoma. Cure rates of 66% to 97% have been reported in cattle and horses

54 Treatment c) Orbital exenteration and radiation therapyInvasive conjunctival squamous cell carcinoma should be treated by otbital exenteration and radiation with interstitial impant radiotherapy. Implants are inserted into the eyelid skin of ten the latter is closed over the exenterated orbit. Postoperative therapy: should include antibacterial agent and a mydriatics

55 Dry Eyes (Keratoconjunctivitis Sicca)Definition: Dry eyes or Keratonconjunctivitis Sicca (KCS) is a complex disease involving the eyelids, the tear film, and the ocular surfaces (corneal/conjunctiva) of animals and man. It is an external eye disease due to deficient tear production, unstable/poor tear quality, poor tear distribution, and/or poor eyelid mechanics.

56 Dry Eyes cont…. The tear levels are measured by Schirmer Tear Test Strips and the ocular surface is evaluated with flourescein and/or Rose Bengal stains. The most common symptoms are excessive mucus, red eyes, increased blinking, “dull” or dry ocular surface.

57 Animals Affected Animals Affected: Dry eye is one of the most frequently diagnosed canine ocular diseases. While dry eyes can occur in any animal, it is much more common in dogs than in cats. Brachycephalic (characterized by short muzzles and prominent eyes) dogs tend to be affected more often with dry eye. Breeds of dog commonly affected with dry eye (breed-predisposed or inherited) include the following:

58 Beagle Boston Terrier Bulldog ChihuahuaCocker Spaniel Dachshund Miniature Schnauzer Lhasa Apso Pekingese Shih Tzu West Highland White Terrier Yorkshire Terrier Bloodhound Pug Cavalier King Charles Spaniel Samoyed

59 The Importance of Tear FunctionNormal tear production is very important. The tear film provides multiple functions. To smooth out microscopic ocular surface (corneal) imperfections that are normally present. This “smoothed out” surface provides an optically clear image for the inner portions of the eye so vision is not distorted. To flush foreign debris from the ocular surface and conjunctival sac.

60 The Importance of Tear Function cont…To provide lubrication for gliding the eyelids and third eyelid over the surface of the eye, much like the windshield wipers over a car’s windshield. Eyes can be uncomfortable if the eyelids drag across a dry surface. To supply nutrition/immune factors to the ocular surface. The corneal surface is normally without blood vessels and tears deliver nutrients and immune factors

61 The Importance of Tear FunctionWithout normal tears, the ocular surface can become ulcerated and infected (with bacteria, viruses, or fungi), pigmented and/or scarred. Infected ulcerations can progress to ocular perforations, and excessive pigmentation or scarring can lead to blindness

62 Tear Components Normal tear film has three basic components. The outer layer of tears prevents evaporation of the underlying layers. This oily layer comes from the Tarsal glands which line the eyelid margins. The middle or aqueous layer of tears consists of mostly water with nutrient and immune factors. The lacrimal and third eyelid glands supply this component of the tears. The inner mucoid layer of tears helps bind The entire tear film to the uneven ocular surface. The conjunctival goblet cells secrete this portion of the tears. Together, all three layers mix into a natural physiologic balance to form the ocular tear film.

63 Causes of Dry Eye Breed predisposition or inherited factors, usually due to an underlying autoimmune conditions in which the immune system attacks the tear glands. Congenital tear deficiency in certain breeds (e.g.: Yorkshire Terriers,) Chronic eyelid infections/blepharitis Drug induced/toxicity Concurrent metabolic diseases: hypothyroidism, diabetes, Cushings disease

64 Causes of Dry Eye Irradiation Neurologic diseasesSystemic infections (such as distemper virus or septicemia) Traumatic injuries to the head or orbit Surgical excision of tear-producing glands (“cherry eye” removal) Concurrent immune-mediated diseases and skin allergies, as tear glands are modified skin glands

65 Treatment Protocol: There are three general approaches for treatment of dry eye. Correct the primary problem that is decreasing tear levels (if possible) Stimulate the tear gland to increase tear levels Supplement the eyes with artificial tears, topical antibiotics and lubricants Surgery (see below)

66 Unfortunately, only a few patients will resume normal tear levels with correction of the primary disease. Most patients will require additional therapy for their dry eyes. The most common topical medications to stimulate tear production are Cyclosporine (Optimmune) or Tacrolimus. These medications will stimulate tear production to normal or near normal levels in approximately 70-75% of the dogs affected by dry eye. These medications usually require twice daily administration for the remainder of the dog’s lifetime. They cannot be mixed in the same bottle with artificial tears, antibiotics, or other medications, so additional topical treatments are often necessary

67 Additional medications are often required to supplement the subnormal tear levels, control secondary infections, break up mucus accumulation, and heal ocular surface diseases (e.g. corneal ulcers or abrasions). These supplemental medications may include: artificial tears/ointments, antibiotics, mycolytic agents, anti-inflammatory drugs, Vitamin A,. A common supplemental eye drop is KCS Solution, which is a mixture of artificial tears, and antibiotic, and a mucolytic agent (acetylcysteine) which helps break up mucus ocular discharge.

68 Each dry eye patient is an individual and requires customized therapy depending upon the ocular needs of the patient. For this reason, it is important that the ophthalmologist re-examine the patient after treatments have begun. A few dry eye patients will resume tear production, and medication can be discontinued. The majority of them, however, will need medications administered daily. The frequency of treatments depends upon the patient’s ability to produce tears. Both the ophthalmologist and client working together can help control the dry eye condition and maintain visual and comfortable eyes

69 Surgery Patients that cannot receive frequent therapy or are non-responsive to therapy may be candidates for surgical procedures. An eyelid surgery (canthoplasty) may be necessary to shorten the eyelid opening, decrease ocular surface exposure, and prevent tear film evaporation. Another procedure is re-routing one of the salivary gland ducts to the tear sac to allow saliva to cover the eye. This “natural” artificial tear is similar in composition to normal tears and will keep the eye moistened.

70 Surgery of the nicitating membraneThe third eyelid (membrane nictitans) is situated infero-medially in the anterior part of the orbit between the eyelids and the globe. The third eyelids protects the globe and secretes and distributes the tears and frequently used as a protective (patch) for corneal ulceration and laceration. The nictating membrane is frequently affected by neoplasm, third eyelid gland protrusion or prolapse, foreign bodies and inflammation

71 Neoplasia Ocular squamous cell carcinoma is the most common tumor of the third eyelid. Most third eyelid tumor including squamous cell tumors arise from the conjunctiva. Tumors of the third eyelid that do not originate from the conjunctiva include third–eyelid gland adenocarcinomas, fibrosarcomas and lymphosarcomas.

72 Clinical signs The tumor affecting the third eyelid initially appears as an area of hyperemia. The lesion because raised and occasionally has a papillomatous appearance, the diagnosis is confirmed by impression smears or biopsy

73 Treatment Treatment of squamous cell carcinoma of the third eyelid usually requires removal of the entire eyelid. a) Small neoplasm on the anterior surface of the nictitating membrane are excisable from the cartilaginous base using blunt curved scissors sparing the third eyelid, is controlled by direct pressure and sometimes by application of local vasoconstrictors suturing is possible using 3-5 absorbable sutures but in many cases small lesion can be left to heal by second intention.

74 b) If the membrane is extensively involved, its excision may be necessary at the base. If the membrane is infiltrated by neoplasm, the gland at the base must be removed. Hemorrhage is profuse and is controlled by direct pressure. Topical and systemic antibiotic are indicated in such case. N.B. Squamous cell carcinoma of the nictitating membrane may frequently recur after surgical removal and may invade the oribit by haematogenous routes.

75 Surgical treatment of cancer eye was possible particularly in early stages. Surgical resection of the 3rd eyelid or removal of the whole eye was resulted in a permanent cure. However more than 60% of cases recur and it is not good practice to continue to breed from treated cattle or from their progeny

76 The masses were cleaned, measured and photographedThe masses were cleaned, measured and photographed. The observed lesions were surgically treated when indicated through a wide surgical excision in the surrounding healthy tissues by 1-2cm was attempted under the influence of xylazine (xylaject, ADWIA Co., A.R.E) at a dose of 0.05 mg/ kg. b.w. for large ruminants and .1 mg/kg. b.w. for sheep premedicated with atropine sulfate at a dose of 1-2 mg/ 40 kg.b.w. and local analgesia using Lidocaine Hcl 2%

77 Treatment of cancer eye depends on its location and degrees of involvement of the ocular structure. Surgical procedure includes third eyelid resection or enucleation of the invaded entire globe and lid margins was performed after Weaver et al. (2005) when the tumours have spread to the extent that the eyeball was blind and parotid or retropharyngeal lymph nodes were not involved.

78 Procedure of third eyelid resectionThe animal was tranquilized and maintained in standing position; analgesia was induced by local infiltration of the base of the eyelid after instilling topical anasthetic solution (0.5% lidocaine) into the conjunctival sac. The third eyelid was drawn out by traction with forceps where the eyelid was deeply excised to cartilage with curved scissors .The haemorrhage was controlled with adrenaline-soaked swab.

79 The second lesion was detected at the frontal-perietal area of 5 years old sheep. The neoplasm showed severe local invasiveness to the supraorbital region and nasal cavity with unilateral purulent bloody nasal discharge. The animal showed great-disturbed health condition and sever enlargement of the prescapular lymph node. The owner was advised to discard the animal. Microscopically, cell nests in all distinct stroma were identified )Fig. 24).

81 The ocular lesions of SCC were elevated pea shaped overgrowths invaded the third eyelid (8 cases), corneoscleral junction, bulbar and palpebral conjunctiva (4 cows). All the affected animals were female and aged 5-8 years. The overgrowths were pink, irregular in shape, nodular, ulcerated and easily to be bled. The eyeball of the affected eye was very small in size in comparison to the other eye. The associated signs were conjunctivitis, blepharospasm, keratitis and corneal opacity.

84 Fig.(29): SCC of the third eyelid in a mixed breed cow (A) and the excised mass (B).

87 The left eye of a stallion with mucopurulent discharge and a pink nodular mass on the cornea, limbus, and bulbar conjunctiva

88 Destruction of the eyeball was found in addition to invasion of various periorbital structures in 5 cows leading to growth of large, unsightly foul smelling tumour. The partid lymph node was involved. The affected cows continued to eat and produce milk reasonably well but tends to lose its weight .

90 Hypertrophy and protrusion of the nictitans gland over the free border of the third eyelid is of characteristic appearance (popularly known as cherry eyes) and is relatively common. It should be distinguish from neoplasia which is uncommon

91 Cherry eye is the common name for a the condition caused when the gland of the third eyelid of the dog, otherwise known as Harder's gland or nictitans gland, becomes inflamed, swells up, pops out of place on the bulbar side of the third eyelid, and becomes more inflamed, swollen and irritated such that it becomes bloody and ulcerated, and can cover 1/2 to the whole eyeball of the dog

92 Any dog can develop cherry eye, but there are several breeds that appear to have a higher incidence of developing it in both eyes. They are: the Beagle, Bloodhound, Boston Terrier, Bulldog, Bull Terrier, , Saint Bernard, and Shar-Pei. Dogs can acquire this condition at any age and it affects males and females equally.

93 What causes it? The exact cause of cherry eye is not known, but it is strongly suspected that it is due to a weakness of the connective tissue that attaches the gland to the surrounding structures of the eye. The weakness of the connective tissue allows the gland to prolapse. Once the gland prolapses and is exposed to the dry air and irritants, it can become infected and/or begin to swell. The gland often becomes irritated, red, and swollen. There is sometimes a mucous discharge and if the animals rub or scratch at it, they can traumatize the gland further or possibly create an ulcer on the surface of the eye.

96 A prolapsed gland of the third eyelid (or "cherry eye") is thought to be associated with a laxity of a small ligament which holds the gland in a normal position behind the third eyelid. The gland is a tear producing gland, and produces about 30% of the tears, while the main orbital lacrimal gland produces the rest.

97 The treatment for cherry eyeThe treatment for cherry eye is always surgical. The procedure of choice is usually to replace the gland and tack it in place with a suture. There are usually not any complications following this procedure but there are a few things for the owner to consider: The stitch could come undone and scratch the eye. The eye will become reddened and painful. The dog will be pawing at the eye. The stitch needs to be removed and the pain will go away.

98 The gland may not be anchored well enough to hold permanentlyThe gland may not be anchored well enough to hold permanently. If this is the case you'll still see a cherry eye present and the surgery will need to be performed again. The dogs eyes will be inflamed and swollen following the tuck procedure, it will take a few days for this to go away. In the mean time your veterinarian will probably prescribe some eye drops to use for inflammation.

99 Another surgical option for cherry eye is to remove a small amount of tissue from above the third eyelid. Sutures are then used to close the gap and tighten the third eye lid into place. Things to consider for this option include: The eye will be red and inflamed while the sutures dissolve. The suture may not be tight enough to replace the third eyelid or there may not have been enough tissue removed (a big enough gap made to replace the third eyelid).

100 The last option is surgical removal of the gland itselfThe last option is surgical removal of the gland itself. This should be avoided. The third eyelid is important for tear production and if the other tear producing glands fail then dry eye is the result. Dry eye or keratoconjunctivitis sicca (KCS) is uncomfortable for the pet and will need to be treated daily, usually with an artificial tears ointment. If cherry eye goes untreated then the gland will dry out and the dog may start to paw and scratch at the eye causing further damage to the third eyelid tissue. The dog could also scratch the eye and cause a corneal ulcer.

101 Dogs that have the gland of the third eyelid surgically excised have a greater risk of development of a dry eye (KCS ) than dogs with intact third eyelid glands. It is thought that should the main orbital lacrimal gland be damaged later in life that there is no "back-up" for tear production. Dry eye is a serious eye condition that is difficult to treat

102 Unilateral protrusion of the nictitans gland was diagnosed in 5 months old Brussels griffon dog as rounded reddish pea-like mass at the medial canthus of the eye ball .The gland was swollen, inflamed and accompanied by ocular discharge. Manual replacement of the prolapsed gland was attempted but recurrence was noticed. Definitive treatment was obtained by replacement, inverting, and anchored the gland to the adjacent perioribital tissue

103 Although certain breeds of dogs such as cocker spaniel, Beagle, Pekingese, Basset Hound and English Bulldog are said to be predisposed to its development (Morgan et al., 1993). It was recorded in Brussels griffon dog by the present study

105 Infectious Bovine Kerato-conjunctivitis (IBK)IBK is the most widespread ocular disease of cattle generally felt to be result of moraxella bovis infection, other microbial agents may also be associated. This disease causes considerable economic loss in both beef and dairy herds. The disease is generally self-limiting and responds well to a wide variety of anti-infective agents. Moraxella bovis infection causing kerato-conjunctivitis has also been observed in buffaloes and caprines and is referred to as (pink eye).

106 Infectious Bovine Keratoconjunctivitis Pink eye, contagious ophthalmia, New Forest disease Worldwide distribution Large economic impact Millions lost due to decreased weight gain, cost of feeding, cost of treatment

107 Infectious Bovine Keratoconjunctivitis Moraxella bovis: gram negative bacillus Other pathogens may contribute to severity including IBR, and Mycoplasma sp. Rough (hemagglutinate) and smooth colonies found Only rough form felt to be associated with clinical disease Contain cell surface pili that promote cellular adhesion and enhance ability to overcome host defense

108 Infectious Bovine Keratoconjunctivitis Occurs primarily during summer months Source of infection New animal or previously affected one Smooth form may transform to rough form with increased UV light Transmitted by handlers, mechanical vectors (face fly, house fly, stable fly), fomites

109 Infectious Bovine Keratoconjunctivitis All breeds susceptibleBos taurus >> than Bos indicus Herefords and hereford crosses Younger > older Increased exposure to UV light

110 Symptoms a) The infection is more sever in young animals. Initially there is blepharospasm, epiphora and photophobia. b) The conjunctiva is affected first but the cornea is normal. c) A raised central corneal zone then appears, enlarges, elevates and slough leaving a shallow corneal ulcer which in young animals becomes extensive and deep. d) Circumcorneal vascularization occurs and progresses toward the central lesion which itself becomes abscessed or perforates (or both). The central abscess sloughs and is replaced by granulation-like tissue

111 Infectious Bovine KeratoconjunctivitisClinical signs 75% unilateral; bilateral involvement is frequent Decreased feeding, milk production, weight gain Epiphora, blephorspasm, photophobia, chemosis, hyperemia, mucopurulent discharge, corneal abscess, ulcers, vascularization, uveitis, scarring, perforation, blindness.

112 Treatment Since M. bovis is usually sensitive to chlormphenicol, the antibiotic is instilled into the eye after cleaning with normal saline or boric acid 2%. If corneal ulceration has not developed, subconjunctival application of steroids can be considered. N.B. infectious conjunctivitis in sheep may be associated with chalamydia infection and may occur as an outbreak in lambing season. Affected animals show moderate to sever follicular conjunctivitis which may persist for 2 to 3 weeks. Topical application of tetracycline or chlormphenical may shorten the course conjunctivitis.

115 Affections of the cornea Wounds of the corneaWounds of the cornea are usually caused through injuries by sharp or pointed foreign bodies as a sharp piece of wood, nails, barbed wire or glass. They are more common in horses and dogs. These wounds are either superficial deep or penetrating with the result of opening the anterior chamber. The condition can be diagnosed when it is not penetrating by instillating few drops of 2% flourescin solution for few minutes, then it is washed by normal saline solution. The erosion will appear as a green spot on the corneal surface.

116 Symptoms In most cases there is sudden onset of pain, blepharospasm and excessive lacrimation. 2. In the early stages there is a fear of light (photophobia) and the eye appears semi-closed. The erosions can be seen on the cornea by thorough examination of the eye. 3. The defect on the cornea is surrounded by turbidity resulting from the cellular infiltration and the extent of corneal damage and ulceration can be checked by the use of fluorescein dye.

117 4. This may be followed by formation of new blood vessels on the periphery of the sclera (vascularization of the sclera). This refers to the starting of healing process. 5. Perforating wounds of the cornea are characterised by aqueous loss from the anterior chamber of the eye, prolapse of the iris and sometimes the lens. The prolapsed iris frequently seals the wound. 6. The prolapsed iris shows a great tendency to bleeding and formation of granuloma (iris staphyloma) or adhesions between the iris and the cornea (anterior synechia).

118 Complications of corneal trauma: include hyphaema, iris damage, collapse of the anterior chamber, synechiae formation, lens luxation, loss of vision and glaucoma.

119 Treatment: 1. The eye is washed with warm boric acid solution 3% and under the effect of local anaesthsia, search for the presence of any foreign body. 2. Superficial epithelial defects can be treated by the application of topical broad spectrum antibiotics effective against G-ve organisms (e.g. tobramycine or gentamicin)

120 3. Perforating wounds of the cornea with prolapse of the iris is treated by cutting of the prolapsed part of the iris which may be infected. The corneal wound is then sutured with fine silk using a special needle for the cornea. The corneal wound can be covered with a part of the conjunctiva which separated from its attachment to the sclera at the upper part of the eye. The part of the conjunctiva is then sutured to the inner aspect of the third eyelid. The sutures can be removed 10 days later, daily application of antibiotic eye ointment to prevent adhesions between the cornea and conjunctiva. Atropine 1% solution can be instilled in the eye every 8 hours to prevent adhestions between the iris and cornea. 4. Systemic antibiotic and non steroidal anti-inflammatory (e.g. Flunixin meglumine) can be useful in complicated case.

121 Keratitis Keratitis is the inflammation of the cornea and cause partial to complete blindness in animals depending up on its severity. Mostly it occurs due to injury or infection. Aetiology. The causes are the same as those mentioned for conjunctivitis, with which it frequently associated.

122 Classification of keratitisKeratitis may be superficial, deep or ulcerative. Superficial keratitis affects the superficial layers of the cornea, especially the epithelial layer. Since the stroma remain unaffected, the vision is lost only partially. In deep keratitis there is full thickness involvement of the cornea resulting in complete loss of the vision. Due to sever inflammatory reaction, neoascularization of the cornea occurs

123 Ulcerative keratitis Ulcerative keratitis: is of serious nature and if not treated properly or well in time the affected eye may be lost as a result of sever ulceration. It is sequel to either trauma, foreign body, distichiasis , entropion, superficial corneal erosion or tumors of the lid margins

124 Clinical signs a) loss of corneal transparencyb) The cornea appears hazy in superficial cases and milky and dense in deep keratitis c) Neovascularization is seen in cases of deep keratitis d) Aqueous flare is common in superficial keratitis of traumatic origin e) Ophthalmoscopic examination shows floating of epithelial cells in the aqueous humor corneal ulcer ulcers are evident in ulcerative keratitis fluorescent dye gives light fluorescent green color to the affected part if ulcer is present.

125 f) Signs of pain, photophobia, lacrimation and blepharospasms are present in deep and ulcerative keratitis. g)Pannus: occur rarely and seen at the center of the cornea. It is characterized by presence of fibro vascular tissue in the cornea below the epithelial layer. The lesions appear pinkish or hazy near the periphery of the cornea

126 Possible complications of corneal ulcers1- Opacity of the cornea: This ensues when the ulcer has destroyed some of the corneal fibrous tissue which always replaces by white fibrous tissue resulting in permanent opacity. 2- Keratocele: characterized by the protrusion of the Descement's membrane beyond the corneal surface, owing to erosion of the superficial layer of the later

127 3- Anterior synechia characterized by adhesion of the iris to the cornea. 4- Iris staphytoma Which is the protrusion of the iris through the ruptured cornea. 5- Corneal fistula Which ensues when the Descement's membrane is ruptured.

128 Treatment. 1- Most cases of superficial or deep keratitis respond farourably to subconjunctival injections of corticosteroids and antibiotic. Some authors prefer chlormphenicol topicolly and gentamycin (10mg) subconjuntivally. N.B. subconjunctival injection should be repeated an alternate days. 2- Atropine eye ointment helps to reduce pain.

129 3- In deep keratitis: ,administration of vitamin–A along-with B-complex, on alternate days helps in the early resolution of the lesion In ulcerative ceratitis: after cleansing of the eye with boric acid 2% or normal saline one of the following could be used: a) Simple superficial ulcer: topical antibiotic and atropine beside correction of the lid defect (entropion, cilia) b) Uncomplicated deep ulcer: topical antibiotic, atropine, antiprotease agent and debridement beside third eyelid flap complicated deep ulcer and descematocele; topical, subconjun-ctival and systemic antibiotics subpalpebral lavage) beside antiprotease agent, conjunctival or third–yelid flap and conjunc-tival pedicle graft.

130 Leucoma (Corneal Opacity)This means the lack or loss of transperency of the cornea. It mostly arises from keratitis or wounds in the cornea. The condition may also be congenital. It usually interferes with the vision especially when located at the level of the pupil. Treatment: recent cases can be treated by application of an irritant as calomel insufflation, 3% yellow oxide of mercury twice daily. The condition can be treated also by either cortisone eye ointment, providing that there is no corneal injury, or by subconjunctival

131 injection of cortisone solutioninjection of cortisone solution. Corneal grafting has been done with success in human being. In some instances opacity can be touched with silver nitrate sticks for few seconds then washing with normal saline solution several times.

132 Iris Staphyloma Iris Staphyloma:the term, iris staphyloma, refers to the prolapse or protrusion of the iris through a ruptured cornea. The condition is characterised by the formation or appearance of granuloma like swelling beyond the level of the opened cornea. Treatment It is only treated surgically by resection of the prolapsed iris as early as possible to guard against introduction of infection. Then application of atropine if the protruded iris in the centre or eserine or pilocarpine if the protruded part in the periphery. The resultant ulcer is then covered by a fold of the conjunctiva.

133 Corneal Xerosis Corneal Xerosis A condition characterized by dryness of the cornea with necrosis of the epithelium. It is occasionally seen in dogs affected wth canine distemper and in cases of paralysis of the fascial or trigeminal nerve. It is also met with in cases of ectropion and vitamin A defeciency. Corneal Dermoid This is a congenital growth of more or less normal skin in the conjunctiva or cornea. The hair which present on its surface may irritate the cornea and conjunctiva. Correction of the condition is by surgical dissection of the dermoid under the control of local infiltration anesthesia. This is followed by local application of antibiotic ophthalmic ointment

134 Affections of the lacrimal apparatus1- Stenosis or obstruction of the lacrimal canal: The condition is more common in horses and dogs, less than in other animals. It may be congenital or as a result of inflammatory thickening of the mucus membrane lining the duct. It may also be due to either occulusion of the duct from inside by any foreign body or from outside due to the pressure from the surroundings as a tumour in the nasal cavity.

135 Symptoms The main symptom is the contstant flow of tears from the medial canthus of the eye. This is usually accompanied with purulent conjunctivitis, the tears are accompanied with the purulut discharges which usually irritate the skin underneath and the hairs are sticky together

136 Treatment: Internal obstruction of the lacrymal canal can be corrected by washing the canal with 3% boric acid solution through a blunt stout needle introduced through its nasal opening. In cases of occlusion of the canal due to its inflammation, frequent bathing with warm antiesptic solution is essential with the application of antibiotic eye ointment 3 times daily.

137 Panophthalmia Panophthalmia is a term given to the accumulation of pus inside the eyeball. Aetiology: 1- Injury and infection of the eye, sometimes following accidental and operation wounds of the organ. 2 It may be a sequel to ulceration of the cornea. Symptoms: there is an intense inflammation of the eye and a perforation of the cornea is usually present, discharging pus. There is an extreme pain. The eye appears to be swollen if the pus can not find its way to outside. When the pus is discharged, the affected eye seems to be smaller in size. The process may become aggrivated by phlegmone, meningitis, septicaemia or pyaemia.

138 Treatment: The only indicated treatment in such cases , is the extirpation of the eyeball .