Ophtho1- Conjunctiva

• mobile, elastic mucous membrane
• Palpebral: lines eyelids
• Bulbar: lines exposed surfaces of globe
• Fornix: cul-de-sac formed by reflections of conjunctiva at transition from lid to globe
• Nictitans: covered palpebral and bulbar surfaces of nictitating membrane

• tarsal plate of eyelid margin
• limbus
• nictitans leading edge (cartilage)

• non-keratinized stratified squamous epithelium with goblet cells between epithelial cells
• substantia propria= loose connective tissue, fenestrated capillaries, lymphoid tissues
• Subconjunctival space= potential space

• allows smooth gliding of NM and lids over globe
• immune protection for ocular surface
• leaky barriers allow movement of antibodies, inflammatory cells, etc to surface
• mucus layer of tear film produced by goblet cells
• mobile blood supply

• mostly gram + (staph and strep)
• small quantities of gram - and occasional fungal (E. coli, Pseud, Acinetobacter)

• dermoid: ectopic island of skin
• eyelid agenesis: failure of formation of portion of eyelid margin (cats- upper lid)

hyperemis, chemosis (swelling), follicles, ocular d/c

• Epinephrine drop with blanch conjunctival vessels rapidly, but not episcleral vessels
• if you rub a Q-tip across the eye, conjunctival vessels will move with it, but episcleral vessels will not move
• conj vessels are tortuous; episcleral vessels are straight

• Cytology is indicated in ALL SPECIES
• Culture is only indicated with cats, sometimes food animals, almost never is dogs or horses
• IFA, PCR, VI rarely

• keratoconjunctivitis sicca!!!!!!!
• follicular conjunctivitis
• allergic/ atopy
• drug sensitivity
• non-specific response to illness
• [primary bacterial infection is so so rare]

Schirmer tear test (b/c KCS is so common in dogs)

• can be due to immune-mediated causes or environmental irritants
• common in young large breed dogs
• clinical signs include large lymphoid follicles, hyperemia, and mucoid d/c

• topical dexamethasone TID then tapered
• topical cyclosporine good for repeated episodes

• seasonal signs
• pruritus +/- follicles and d/c
• +/- concurrent blepharitis
• +/- periocular alopecia

• clinical signs
• cytology shows eosinophils and neutrophils

• topical corticosteroids (dexamethasone)
• treat underlying allergies (antihistamines, ASIT, etc etc)

infectious

• Herpesvirus (esp if there is corneal involvement)
• Chlamydia
• Mycoplasma
• Calicivirus
• eosinophilic keratoconjunctivitis

• L-lysine for the rest of life
• repeat course of famcyclovir for at least 2 weeks post-resolution
• stress management/ avoidance

chemosis, usually bilateral, mucopurulent d/c, +/- pseudomembrane (chunk of mucus that adheres to conjunctival surface)

cytology- inclusion bodies in epithelial cells 7-14 days post infection (may not see if early in infection)

• oxytet or chloramphenicol ointment TID
• oral doxycycline for 3 weeks

zoonotic potential!!! causes pinkeye in humans

• mild to moderate conjunctivitis
• oral mucosal ulcers (unique to this disease)

supportive (disease is self-limiting)

• usually unilateral
• mild hyperemia
• pseudomembranes
• serous to mucopurulent d/c

• clinical signs
• cytology (coccoid clusters on epithelial cell wall)

oxytet or chloramphenicol topically or oral doxycycline

• topical cyclosporin A BID, may try to discontinue after 2-3 months
• megesterol acetate, 4-5 days
• topical corticosteriods, may discontinue after 4-6 weeks

fly strike, seasonal allergies, dust, parasitic, equine recurrent uveitis, chronic nasolacrimal obstruction, eosinophilic keratoconjunctivitis, bacterial

• IBR (herpesvirus)
• infectious bovine keratoconjunctivitis (moraxella bovis)
• parasites

hyperemia, chemosis, serous to mucopurulent d/c, +/- peripheral corneal edema/ ulceration

symptomatic txt +/- topical antibiotics

epiphora, blepharospasm, photophobia, conjunctival hyperemia and chemosis, central corneal ulceration/ abscess

• IM oxytet
• florfenicol (nuflor)
• tulathromycin (draxxin)
• tilmycosin (micotil)
• prevent with fly control

• chlamydia
• mycoplasma (conjunctival hyperemia and chemosis, keratitis with vascularization of cornea)
• txt: IM oxytet

• Thelazia 
• lives in conjunctival fornix, can live in nasolaccrimal system
• can see them cross the cornea

ophthalamic organophosphates

• Onchocerca
• conjunctivitis and uveitis, depigmentation, +/- hypertrophy of conjunctiva and limbus
• Dx by conjunctival biopsy

systemic NSAIDS, ivermectin

• SCC
• papilloma
• hemangiosarcoma
• melanoma
• lymphosarcoma
• mast cell tumor

leading edge

T-shaped cartilage

• lacrimal gland at the base (GNM- gland of the nictitating membrane)- produces aqueous portion of tear film
• covered in goblet cells- produces mucus portion of tear film

dorsolaterally (except birds- ventrolaterally) when the globe is retracted.

• retropulse the globe (gently push globe back into orbit)
• use topical anesthetic and forceps to grasp leading edge to look at the back of the NM (r/o FB, look for lymphoid follicles)

• scrolled cartilage
• prolapsed gland of the nictitiating membrane (cherry eye)
• neoplasia
• inflammatory diseases (follicles, plasmoma)

• vertical portion of the T-cartilage is kinked, preventing normal conformation to corneal curvature--> decreased spread of tear film
• tops of horizontal potion curl outward secondarily

• incision through conjunctiva over vertical cartilage--> imbricate edges--> 2 parallel incisions through cartilage to excise kinked portion
• cautery used to heat cartilage and bend back to normal position (newer technique)

• "cherry eye"
• congenital weakness of the anchoring ligament--> prolapse and swelling of GNM over the margin of the third eyelid
• cockers, bulldogs, beagle, boston terrier, mastiff, burmese cats

• REPLACE THE GLAND!! don't remove it b/c it produces up to 50% of aqueous portion of tears (these breeds are also ironically predisposed to KCS)
• pocket imbrication technique- expose bulbar surface of NM, make elliptical incision around gland, undermine conjunctival epithelial and create pocket, cushings pattern to wrap pocket around gland

• triple antibiotic solution TID 7-10 days
• risk for KCS
• 25% recur
• nictitans may remain slightly elevated

• [enophthalmus] loss of retrobulbar muscle and fat d/t dehydration/ cachexia/ old age, sympathetic denervation, active globe retraction (pain, tetanus)
• [exophthalmus] retrobulbar space-occupying mass

• bilateral third eyelid elevation- cause unknown
• often associated with diarrhea

lymphosarcoma

adenocarcinoma of the GNM (may look similar to cherry eye)

• follicular conjunctivitis (lymphoid follicles visible on conjunctival surface, young dogs)
• plasmoma

immune-mediated lymphoplasmacytic inflammation of the NM

• reddening, thickening, depigmentation of the NM margin
• bilateral
• often associated with chronic pannus!
• Dx on clinical signs +/- cytology

• corticosteroids topically
• topical cyclosporine or tacrolimus
• limit UV light exposure

a sign of underlying disease; a primary diagnosis

• presence of lymphoid follicles
• bulbar surface of nictitans
• 0.1% dexamethasone topical

corticosteroids

SCC

• enophthalmos (cachexia, dehydration, muscle, fat atrophy)
• Horner's syndrome
• exophthalmos (retrobulbar space occupying mass)
• Haw's syndrome (cats)