The Wet Eye Flashcards
What does epiphora indicate?
wet face d/t tearing, does NOT indicate cause
- lack of drainage
- irritation -> reflex tearing
Which direction does blinking occour in?
lateral-medial brings tears to medial canthus
Outline the nasolacrimal system
- inferior and superior puncta medially
- lead to canaliculus on each side
- connect to lacrimal sac
- continue as nasolacrimal duct (INTEROSSEOUS part)
- potential additional duct openings (can -> drainage into throat not nose)
- ends in nasal punctum lateral nasal wall
How doesthe nasolacrimal system of rabbits differ to other smallies?
- single, large ppunctum lower lid
- nasolacrimal duct interosseous is tortuous and follows tooth roots (1* maxillary incisor) -> blockage with tooth prblems
How does the nasolacrimal system of horses differ to smallies?
- large, visable nasal punctum
- cannulation of this is possible
- retrograde flushing of NLD
What does a delayed or absence of fluorescin in the Jones test indicate?
- potential blockage
- indication to FLUSH and find out more
What can damage of the NLD with a canula dispose to?
stricture
What could be used instead of a nasolacrimal cannula to flush ducts?
- small IV caqtheter`
Risks of flushing the nasolacrimal duct?
- damage and stricture-
- pain (always use topical anaesthetic proxymetacaine, do not force fluid, pulsate it)
- aspiration of fluid (tilt head down, or inflate cuff if under GA)
Potential causes of blockage -> epiphora?
> imperforate punctum (congenital) - uni or bilateral - upper +- lower puncta - may also affect caniliculi (malformation or aplasia) > closed puncta (2* to inflame/trauma) - eg. cat flu/herpes when young
ID and Tx of puncta blockage?
- cannulate other punctum ipsilaterally
- pulsate fluid and look for pulsating bulge in conjunctiva
- cut if located, and place large 3-0/4-0 non absorbable suture cannulation for 14d to avoid closure
> if cannulation not possible consider further dx
= Dacryocystorhinography xray study with contrast - CT with contrast
ID and TX NLD blockage?
> much more difficult as interosseous - bulging under skin near medial canthus - mucous production - surgical exploration - foreign material - imagine > cannulate with suture again
3 main sources of pain irritants -> epiphora?
- ocular surface (eyelids, TE - poss infection/trauma; conjunctiva, cornea - more common and severe, d/t hairs, eyelid, nerves exposed with ulcers, FBs)
- intraocular structures
- retrobulbar area
Potential causes of 1* eyelid /TE problems
> trauma
inflam/immune/infectious (bacterial/mycotic/parasitic)
- leishmania
- part of systemic derm eg. pemphigus
- Hordoleum (stye) internal meibomian gland infection or external glands of Moll and Zeiss infection
- Chalazion (non painful blockage of sebaceous gland -> granuloma formation around exuded material cuasing 2* trauma to cornea)
- staphylococcal blepharitis (young/adult dogs, hypesenstivity + self harm - skin ulcers, abscesses)
- FB
What is the tx of staphylococcal blepharaiitis?
- clean debride and lance
- protective collar
- Abx, cephalopsporin oral and Fucithalmic topically)
Are long term topical local anaesthetics indicated following FB removal from under the TE?
No
- remove pain sensation will v tear production
- proxymetacaine is cytotoxic with prolonged use and will prevent ulcers healing
What should be used to suture a TE trauma?
- 6-0 vicryl
- round bodied needle
- knots to the superficial side!
What type of forceps are use dto handle delicate tissue?
- Von Graeffe
Treatement of chery eye?
- prolapsed gland of TE
- produces 30% tear film so DO NOT REMOVE, also breeds pdf cherry eye pdf KCS too
- reposition using Morgans pocket technique
- if this fails anchoring techniques though these limit movement of TE so last resort
Which dogs is follicular conjunctivitis seen more commonly? Cuases?
- young dogs
- allergic response to environmental allergens
- bulbar side more obvious
- seen in horses with dust/flies
Prognosis or tx of follicular conjunctivitis?
- will rsolve spontaneously
- lubricant
- if persisting >6 months give topical steroids short term
- sodium chromoglycate (MC stabiliser, must be given before onset)
What 1* infectious agents cause conjunctivitis?
> Clamydophila - young cats - uni/bilateral - v hypeaemic - Doxycyline BID for a month - Always Tx if suspected, can do swabs but stat tx before results if all other causes r/o. > FHV1 - more of a corneal problem - affect conjunctiva 2*
Which 1* infectious agents cause conjunctivitis in large animals?
> IBR - adults: URT, red nose, ocular discharge and redness - in utero -> ocular development problems > Moraxella bovis (Pink EYe) - typically seasonal - fomites - very hyperaemic conjunctivitis > listeria monocytongenes (Silage Eye) - typically seasonal - fomites
Which infiltrative diseases can cause 1* eyelid/TE irritation?
> LPI (dogs)
- aka pannus, CSK [chronic superficial keratitis], corneal LPI
- may affect cornea only, cornea and TE or TE only [plasmoma]
EK (Cats)
- easinophilic keratitis and keratoconjunctivitis
- similar pathophysiology but more eosinophils less lymphocytes
Tx of trichiasis, distichiasis andectopic cilium?
- trichiasis: remove hair or prominent feature
- distichiasis: electrolysis for multiple, wedge resection for single
- ectopic cilium: wedge resection
How does neoplasia of the eyelid differ betweenspecies?
> dogs - commonly benign - meibomian gland adenoma and papilloma - MCT have less aggressive biological behaviour in the eyelid > cats variable, mostly malignant - SCC - melanoma - MCTs > horses/catle, most malignant - sarcoid - SCC potensh v serious - melanoma
How may tension on a wedge resection wound be minimised?
House resection - cut wedge edges parallel instead of V shaped
How are wedge resections closed?
- internal tarsal plate suture
- figure of 8 suture
What conformational problems may affect the eyelid? `
> upper eyelid agenisis in cats - lateral upper eyelid missing (eyelid coloboma) - leads to trichiasis - requires reconstruction > entropion > ectropion
What is the entropion chart?
Awaiting email response!
How may entropion be repaired?
Celsus-Hotz or Hotz-Celsus repair
- remove wedge from under eye
- suture with 6-0 absorbable material
- Rile of Bisection (start at either end then half distance until it is all closed)
What ethics are asscoaited with conformational issues?
- inform owners for showing
- breeding?
- repair only for medical reasons not looks
What intraocular sources may -> epiphora? How?
> glaucoma, uveitis, others
prolonged/intense corneal stimulation cuasing reflex uveitis
- spasm of ciliary and iridial musculature
- miosis and photophobia
What is the tx of iris spasm?
Atropine relaxes ciliary body for ~ week
What type of retrobulbar disease may cause epiphora?
- abscessation/cellulitis (painful)
- salivery gland dz (variably painful)
- neoplasia (rarely painful)
What is reflec uveitis?
- chronic corneal pain d/t ulcer -> psasm of iris and ciliary body
