| Question |
Answer |
| retinaneuroepithelium of the iris and ciliary body |
neuroectoderm |
| cornea, lens, eyelids |
surface ectoderm |
| extraocular musclesvascular endothelium |
mesoderm |
| invaginates, forming the lens vesicle |
lens placode |
| optic vesicle becomes the |
optic cup |
| eventually becomes the lens |
lens vesicle |
| become the neural and pigmented layers of the retina |
the two layers of the optic cup |
| composed of 5 layers |
cornea |
| swelling and painsensitivity to light |
conjunctival discharge |
| blindness resulting from |
alterations in the cornea, lens, humorsdamage to the retina, optic nerveextraocular lesions on the brain |
| excessive or decreased lacrimationopacity of the cornea or lensexophthalmosendophthalmos |
Clinical expressions of disease |
| HistoryPhysical examinationOphthalmoscopic examinationElectroretinographyCultures of lacrimal fluidPostmortem examination |
Diagnostic procedures |
| absence of the eye |
Anophthalmos |
| presence of a single, central eye |
Cyclopia |
| incomplete separation, or early fusion, of paired globes |
Synopthalmia |
| abnormally small eyeinherited defect in Collie dogs |
Microphthalmia |
| inversion of the eyelids trichiasis |
Entropion |
| eversion of the eyelids |
Ectropion |
| rubbing of the eyelashes against the eye surface |
Trichiasis |
| of veterinary importance |
ColobomaCollie eye anomaly |
| failure of complete fusion of the lips of the embryonic choroid fissure |
Coloboma |
| outpouching of neurectoderm |
scleral ectasia |
| a defect in the form of a gap, notch or fissure of part of the eye as a result of improper development of the optic cup |
Coloboma |
| the posterior portions of the eye (optic disc, iris, ciliary body) most often affected |
Coloboma |
| inherited in Charolais cattle |
Coloboma |
| cavitation of the choroid and scleracavity lined by a thinned retinal layer |
Coloboma |
| inheritedautosomal recessiverough and smooth Collies and shetland sheepdogs |
Collie eye anomaly |
| improper development of the optic cupabnormal formation of choroid and retinachorioretinal dysplasia or choroidal hypoplasia |
Collie eye anomaly |
| abnormal retinal vesselsareas of chorioretinal dysplasia or hypoplasiaectasiaoptic discscleraposterior staphyloma± severe visual impairment |
Collie eye anomaly |
| sequelae:retinal degeneration and detachmentintraocular hemorrhage |
Collie eye anomaly |
| initially, the iris forms as a solid sheet of mesodermal tissue |
pupillary membrane |
| pupillary membrane later on, some of this tissue dissipates >> forming the |
pupil |
| delayed or incomplete atrophy of the anterior perilenticular vascular network |
Persistent pupillary membrane |
| in dogs, persistent remnants are common up to 6 months of age |
Persistent pupillary membrane |
| atrophy is frequently incomplete at birth |
Persistent pupillary membrane |
| inherited in:Basenji Chow Chow Pembroke Welsh Corgi |
Persistent pupillary membrane |
| short, threadlike protrusions from the area of the minor arterial circle |
iris collarette |
| Persistent pupillary membraneclinical significance |
obstructed visioncorneal or lens opacity |
| due to dysplasia of corneal endothelium or lens because of contact with the strands |
corneal or lens opacity |
| Developmental anomaliesBlepharitisNeoplasms |
Diseases of the eyelids |
| partial defect (coloboma) involving the upper eyelid is the |
most common |
| abnormal or prolonged fusion or adhesion of the eyelids |
Ankyloblepharon |
| Premature eyelid separation |
Ankyloblepharon |
| essential to protect the immature cornea from infectious keratitis, dessication, and corneal rupture |
Physiologic ankyloblepharon in carnivores |
| persists into the 2nd week of life |
Congenital ankyloblepharon in dogs and cats |
| should have their eyes open at birth |
ruminants and horses |
| inward rolling of the eyelid margin (inversion or infolding) because of inadequate overall length |
Entropion |
| irritation of the cornea by the eyelid skin, cilia, and/or hair |
Entropion sequel |
| very common anomaly in purebred dogs |
Entropion |
| created by undue laxity of an excessively long eyelid resulting in an outward gaping of the eyelid margin |
Ectropion |
| chronic conjunctivitis and keratitis from exposure to debris |
Ectropion sequel |
| presence of an ectopic row of cilia originating from the ducts of the Meibomian glandsusually bilateral |
Distichiasis |
| corneal irritation |
Distichiasis sequel |
| misdirection of the normal cilia |
Trichiasis |
| corneal irritation leading to keratitis and even ulceration |
Trichiasis sequel |
| abnormally placed cilia within the lamina propria of the conjunctiva |
Ectopic cilia |
| their emergence through the palpebral conjunctiva can cause severe corneal irritation |
Ectopic cilia sequel |
| FocalDiffuse |
Blepharitis |
| Hordeolum (stye)Chalazion |
Blepharitis Focal |
| suppurative adenitis of the adnexal glands of Moll or Zeis |
Blepharitis Focal Hordeolum (stye)External |
| suppurative adenitis of the Meibomian gland |
Blepharitis Focal Hordeolum (stye)internal |
| persistent inflammation >> sebaceous secretions extend into the adjacent soft tissues >> granulomatous response |
Blepharitis Focal Hordeolum (stye) sequel |
| DDxadenomafungal granulomalymphoid hyperplasia |
Blepharitis Focal Hordeolum (stye) |
| sterile granulomatous inflammation of the Meibomian gland |
Blepharitis Focal Chalazion |
| Blepharitis Focal Chalazion DDx |
Meibomian gland adenomas |
| Blepharitis Diffuse Types |
ulcerative, seborrheic, allergic, actinic, parasitic |
| Blepharitis Diffuse seen in dermatomyositis in |
Shetland sheepdogs |
| erythema, crusting, vesiculation, erosiondorsum of the nose, inner aspects of the pinna, perioral and periocular regions |
dermatomyositis in Shetland sheepdogs |
| dogs and cats |
Nerve sheath tumors |
| cats, horses, cattle |
Squamous cell carcinoma |
| cats |
Mast cell tumor |
| horses |
Sarcoids |
| most common tumor of canine eyelid (80% of all eyelid tumors) |
Meibomian gland adenoma |
| exact counterpart of sebaceous adenomas |
Meibomian gland adenoma |
| 2nd most common tumor of the canine eyeliduniversally benign |
Melanocytoma |
| non-keratinized, stratified squamous epitheliumgoblet cells |
normal conjunctiva |
| dogs: St. Bernard, Dalmatianlateral canthus or limbus |
Dermoids |
| hereford cattle: autosomal recessive and polygenic trait3rd eyelid, medial canthus, eyelid |
Dermoids |
| rare in domestic species |
Extension of the conjunctiva over the cornea |
| benign, raised, wedge-shaped growth of the conjunctiva |
Pterygium |
| (cattle, horses in western USA and Canada) |
Thelazia sp |
| corneal/conjunctival edema |
chemosis |
| tenacious, sticky exudate |
keratinisation and goblet cell hyperplasia |
| Idiopathic eosinophilic conjunctivitisNodular granulomatous episcleritis (NGE)Necrotic scleritis |
Conjunctivitis types |
| Idiopathic eosinophilic conjunctivitis |
conjunctival counterpart of the eosinophilic keratitis syndrome |
| seen in cats and horses |
Idiopathic eosinophilic conjunctivitis |
| ulcerationepithelial hyperplasia, squamous metaplasiacellular infiltrationlymphocytes, eosinophils |
Idiopathic eosinophilic conjunctivitis |
| nodular lesion of the conjunctival lamina propria |
Nodular granulomatous episcleritis (NGE) |
| Collie, Shetland Sheepdog, Cocker Spaniel, Rottweiler, and Labrador Retriever |
Nodular granulomatous episcleritis (NGE) |
| syn.: ocular nodular fasciitis, fibrous histiocytoma, collie granulomasites: lateral limbus, 3rd eyelid |
Nodular granulomatous episcleritis (NGE) |
| nodular accumulation of macrophages, fibroblasts, lymphocytes, plasma cells in the lamina propria; no collagenolysis and not many granulocytes |
Nodular granulomatous episcleritis (NGE)histologically |
| neoplasia, excessive granulation tissue, cysts, foreign body, focal infections, granulomas, uveitis |
Nodular granulomatous episcleritis (NGE)DDx |
| idiopathic “immune-mediated” disease in dogs; can be mistaken for NGE |
Necrotic scleritis |
| nodular thickening of the bulbar conjunctiva or underlying sclera posterior to the limbus |
Necrotic scleritis |
| destructive lesion with collagenolysisnumerous eosinophils+ macrophages, fibroblasts, lymphocytes (also seen in NGE) |
Necrotic scleritishistologically |
| cattle > horse > dogs and cats |
Neoplasms of the conjunctiva |
| cattleSCC is the most frequent |
predispositions: actinic irradiation, hypomelanosis, IBR virus infection, genetic (Herefords) |
| horse |
predispositions: actinic irradiation, hypomelanosis, IBR virus infection, genetic (Herefords) |
| dog |
primary neoplasms are uncommonhemangiomas, viral papillomas, melanoma and histiocytomas do occur |
| cat |
Neoplasms of the conjunctiva rare |
| faint loss of transparencycan be seen with oblique illumination |
Nebula |
| light gray spotcan be visualized in natural light |
Macula |
| any dense white spotindicates moderate to severe corneal disease |
Leukoma |
| contamination of ulcers with bacteria or fungi>> suppurative destructive keratomalacia |
Suppurative keratomalacia (“melting ulcer”) |
| due to:bystander injury from neutrophilsproteases of bacterial or fungal origin |
Suppurative keratomalacia (“melting ulcer”) |
| sequelaedescematocele and corneal perforation |
Suppurative keratomalacia (“melting ulcer”) |
| specific example: equine keratomycosis |
Suppurative keratomalacia (“melting ulcer”) |
| congenital, developmental anomalies affecting the mucous membrane of the conjunctiva or cornea |
Ocular dermoids |
| failure of the fetal ectoderm to undergo complete corneal “metaplasia”portion of the cornea remains as skin |
Ocular dermoids |
| commonest in the dogtemporal limbusraised islands of skin with:long, soft hair orflattened plaque-like areas with short stiff hairhairs cause local irritationhair removal is simple and effective |
Ocular dermoids |
| an outpouching (ectasia) of the cornea that is lined by uveal tissueembryogenic defectlesionsdark brown or blackperforation is common |
Congenital anterior staphyloma |
| due to the entrapment of groups of epithelial cells in the developing cornealesionsopaque whitecystic enlargement may occur |
Congenital inclusion cyst |
| small corneasporadic in many breedsespecially the miniature schnauzerheritableassociated with cataract formation |
Microcornea |
| Ulcerative Non-ulcerative |
Keratitis |
| etiology:trauma (physcial, chemical)dessicationinfection Moraxella bovis in cattle >> "pink eye“most prevalent in summer (↑ fly activity)FHV-1 in cats >> “dendritic” ulcersimmune-mediated1° degeneration of corneal epithelium |
Ulcerative keratitis |
Alva Jackson
on 2009-10-26
Spanish 3
