Glossary of terms Flashcards
Define eyelid agenesis
= uncommon birth defect, mostly found in cats. Eyelid doesn’t form properly leaving exposed eyeball and the eye can’t be properly hydrated.
Define
Dermoid (conjunctival/ corneal)
= presence of aberrant tissue containing skin, may occur as a result of abnormal differentiation of an isolated group of cells or inclusion of surface ectoderm during closure of fetal clefts. May affect limbus, cornea, conjunctiva and eyelids.
Define PPM
) = a defect of the anterior segment, remnants of the anterior tunica vasculosa lentis and pupillary membrane, which provide nutrition to the eye during development. Start regressing in utero, usually disappear by 6 weeks old. Basenjis predisposed.
Define cataracts
= autosomal recessive inherited in Miniature Schnauzer. Bilateral, usually symmetrical, usually lens nucleus affected, occasionally cortex. Non-inherited types exist and are thought to arise from in utero insults. Usually associated with other ocular abnormalities (e.g. PPM).
Define retinal dysplasia
= abnormal retinal differentiation with disorderly proliferation and disorganization of the retinal layers. Usually primary genetic disorder in dogs. Can arise spontaneously or from external insults.
Define enopthalmos
= globe has an abnormal posterior position within orbit. ‘Normal’ in dolocephalic breeds. Usually just an aesthetic issue.
Define exopthalmos
= normally sized eye pushed forward by retrobulbar SOL or shallow orbits (brachycephalics) lead to protrusion of eyeball in orbit.
Define Buphthalmos (sometimes referred to as hydrophthalmia)
= globe enlargement, occurs due to pressure-induced stretching of the ocular tunics. Often marked and relatively rapid in young animals (less rigid globes than adults). When signs present, animal is usually blind. Differentiate from exophthalmos.
List 3 different retrobullar diseases
Abscess/cellulitis
Neoplasia
Extraocular polymyositis
Define blepharospasm
= rapid blinking of the eye due to involuntary contractions of the orbicularis oculi muscle of the eyelid. It is rapid and the eye may appear closed.
Define blepharitis
= inflammation of the eyelids. Local to glandular structures in eyelid or part of generalized skin disease or systemic disease.
Define trichiasis
= presence of normally located but abnormally directed hairs which contact and irritate the ocular surface. Misdirected hairs can arise from multiple locations.
Define distichiasis
= where an eyelash protrudes from or adjacent to the meibomian gland, can be single, usually numerous, not an extra line of eyelashes as the name suggests
Define ectopic cilium
= usually 1 hair in one location, often the central upper eyelid on the conjunctival side of the eyelid (differentiates it from distichiasis where the hairs emerge on the non-conjunctival side of the eyelid).
Define entropion
= inversion of all or parts of the eyelid margin(s) eyelid hairs are in direct contact with the cornea irritation and corneal pathology. Classified as breed-related/anatomical, spastic, atonic/senile or cicatricial entropion.
Define ectropion
= eversion of the eyelid, common in dogs, usually breed-related (breeds with overlong eyelid and lazity of lateral canthus). Causes increases conjunctival exposure and collection of debris in the lower conjunctival sac, as well as poor tear film distribution over the corneal surface conjunctivitis and increased mucin production.
Define ptosis
= drooping of the upper eyelid, Can result from oculomotor nerve lesions or sympathetic denervation of the eye.
How do you do entropion correction
(simple Hotz-Celsus procedure/ aka Celsus-Hotz) = this is for treatment of entropion in adults (young animal entropion can correct itself so surgery should be delayed until at least 5-12 months old). This is a skin or skin-muscle resection in which an ellipse of skin and/or underlying muscle is removed corresponding to the degree of in-turning.
Define epiphora
(overflow vs NSLD blockage) = excessive watering of the eye
Define KCS (quantitative dry eye)
= reduction in tear production causes increasing corneal inflammation and, ultimately, permanent damage that may prove blinding. Typically a tacky mucopurulent ocular discharge that is adherent to the corneal surface in strings, and recurrent conjunctivitis with or without corneal ulceration that is slow to heal are classic signs.
Define qualitative dry eye
= a type of dry eye (KCS), where there is excessive tear evaporation and is the result of inadequate production of the lipid layer. In contrast, quantitative dry eye is where there is deficient production of the aqueous portion of the lipid film.
Define NSLD blockage
secondary to FB (grass seed awns) in nasolacrimal system is relatively common in dogs. May also occur secondary to granuloma/inflammation in lacrimal sac or canaliculi.
Describe nasolacrimal duct flushing
= may dislodge a FB into the punctum, allowing it to be removed, but incision into the lacrimal sac or nasolacrimal duct may be required.
Define dacryocystitis
= inflammation of the nasolacrimal drainage system, you see mucoid to mucopurulent ocular discharge from lacrimal puncta.
Define hyperemia
= redness caused by the vasodilation of the conjunctival BVs against the white scleral background.
Define chemosis
= conjunctival oedema
Define follicular conjunctivitis
= a type of conjunctivitis, the follicular type is a non-specific reaction to chronic conjunctivitis and is easily recognized by appearance of nodule-like structures outlined by conjunctival capillaries on the conjunctival surface. May resemble vesicle but aren’t fluid filled and instead consist of lymphoid tissue.
Describe prolapsed gland of the TE (cherry eye)
= protrusion of the nictitans gland over the free border of the 3rd eyelid is the characteristic appearance. May be caused by inherent instability of CT which anchors gland at base to third eyelid or a direct consequence of chronic glandular hypertrophy. The prolapsed gland becomes reddened and unsightly.
Describe TE cartilage
= where the cartilage is abnormally kinked, usually in the vicinity of the upper part of the T. Results in eversion or inversion (less commonly) of the 3rd eyelid. Unsightly appearance and functional mobility of 3rd eyelid may be impaired. Developmental in some large dog breeds.
What is another name for LPI of the TE?
(Lymphhocytic-Plasmacytic infiltrate of the third eyelid, aka Plasmoma) = plasmacytic conjunctivitis
Describe LPI of the TE
= an immune-mediated disease of unclear pathogenesis. Painless, generally bilateral thickening of third eyelid with depigmentation of the usually pigmented margin and nodular pink-tan cellular infiltrates (predominantly plasma cells with some lymphocytes).
Describe corneal oedema
= indicative of corneal damage. Not uncommon in horses where it may be primary/dystrophic but is more likely to be secondary to various ocular insults.
Define SCCEDs. What is another name for it?
Spontaneous chronic corneal epithelial defects, previously known as Boxer ulcers and indolent ulcers
Describe SCCEDs
= superficial ulcers that are characterized by a lip of loose epithelium surrounding a denuded superficial stroma.
Describe melting cornea/collagenolysis
= develops as a complication of an existing corneal ulcer rather than as a primary corneal condition. It may occur at any time during ulcer healing and can progress to corneal perforation within hours. Not always possible to determine why it occurs.
Describe Descemetocoele
Descemetocele = exposure of Descemet’s membrane when an ulcerative processs erodes through all the overlying corneal epithelium and stroma. May lie flit deep in bed of ulcer or may bulge anteriorly. Do not take up fluorescein.
Describe corneal perforation
= may occur in advanced corneal ulcers, may develop on the corneal surface allowing drainage of the intraocular contents.
Describe iris prolapse
= the iris tends to prolapse out of its held position in the ciliary body when there is a corneal wound. Iris prolapse occurs when the iris tissue is observed outside of the wound; iris incarceration occurs when the iris tissue reaches the wound without prolapsing outside the eye.
Describe Feline Herpes Keratitis (FHV-1)
= in addition to feline URT disease, this is a very common cause of conjunctivitis, and ulcerative and non-ulcerative keratitis in cats. Virus replicates in epithelial cells of cornea, destroys them and causes linear, branching superficial ulcers accompanied by conjunctivitis and signs of ocular pain.
