Flashcards in The wet eye Deck (60):
wet face due to tearing, doesn't indicate cause, simply an overflow of tears, 2 categories:
- lack of drainage through nasolacrimal apparatus
- irritation --> reflex tearing
What should epiphora investigation focus on?
Location - lacrimal gland
under the dorsolateral orbit, 70% tears
What do the lacrimal puncta lead to?
a canaliculus on each side --> NSLD (intraosseous, potential additional duct openings e.g. nasopharynx)
Describe NSLS in rabbits
- single, large punctum in medial conjunctiva of lower eyelid
- runs in close proximity to root of primary maxillary incisor
- bends over root
- important site for NLD blockage when there are tooth problems
Where does the nasal punctum end?
lateral nasal wall
Outline NSLS in horses
- like in cats/dogs
- BUT have large, visible nasal punctum (retrograde cannulation possible)
Causes - delayed appearance of fluorescein for jones' test
- opening onto nasopharyngeal area
- partial blockage possibly
Absence of fluorescein at nasal planum for jones test indicates
strongly suspicious of blockage but not proof
What should you do with absent or delayed fluorescein appearance in the jones test?
flush with a disposable cannula (cats ==22gz, dogs = 26gz), alternatively use a small IV catheter without the stylette
Risks of flushing the NSLS after Jones test
1. damage to NSLS
2. pain during flushing (TA always proxymetacaine, sedate for some dogs/cats, probably all horses, may require GA, don't force fluid, 'pulse' it
3. aspiration of fluid (avoid inadvertant aspiration into nasopharynx, severe --> aspiration pneumonia, ensure nose tilted down, especially if sedated, OR if GA place an ETT with a cuff)
Causes - blocked punctum/puncta
- CONGENITAL: uni or bilateral, upper/lower, may also affect canaliculi (dysplasia or aplasia)
- POST-INFLAMMATORY/TRAUMATIC: hx of previous dz/trauma, look for clues (scars), might affect rest of NSLS
Tx - blocked punctum/ puncta
Cannulate other punctum, ipsilaterally if possible, irrigate pulsating fluid gently, find a pulsating bulge in conjunctiva, if confirmed, gently cut into it with tip of an 1--blade, may leave or continue with suture cannulation (GA), check other side.
- Under Sd, TA, GA or GA/TA
- if cannulation through punctum not possible, try retrograde cannulation (larger dogs, difficult, requires GA), consider further investigation (dacryoscystorhinography with xray or CT study)
What is dacryoscystorhinography?
In the nasal cavity where there is space in the NSL duct, put contrast in then image with xrays or CT
Tx - blockage of (nasolacrimal duct) NLD in the interosseous part
- more difficult
- manual expression by gentle massage
- explore with sx
- imaging to help dx
- cannulate with suture, tie to skin, both ends, leave 14 d so epithelial cells grow round it.
Sources of irritants causing epiphora
1. ocular surface (eyelids, TE, conjunctiva, cornea)
2. intraocular structures
3. retrobulbar area
Common source of pain in eyelid/ TE
ifxn or trauma
Describe corneal pain as a cause of epiphora
more common than eyelid/TE and potentially severe, problems with hairs, eyelid or TE, exposed corneal nn with ulcer, FB
What usually causes a primary eyelid/ TE problem?
trauma (especially cat claws from fights)
List inflammatory/ immune-mediated/infectious cuases of eyelid irritants --> epiphora
- mycotic (ringworm)
- parasite (demodex dogs, habronema horses)
- mediterranean countries (leishmania)
- immune-mediated (systemic problem e.g. pemphigus)
an internal or external stye affecting primary or third eyelid
- ifxn of glands of Zeiss or Moll (skin cilia, modified sebaceous and sweat glands) = EXTERNAL
- ifxn of meibomian glands (INTERNAL)
= meibomian cyst
- non-painful itself but irritates cornea
- granuloma around extruded sebaceous gland material
What is Staphylococcal blepharitis?
= eyelid inflammation due to staph hypersensitivity
- young to young-adult
- self-harm causes most of the damage
- skin abscesses and ulcers
Tx - Staphylococcal blepharitis - 4
- clean, debride, lance
- protective collar to avoid self-harm (4-6 weeks)
- ABs - oral and topical (cephalosproin orally, Fucithalmic)
- Oral or injectable steroid (short term)
What instrument can be used to hold the eyelids open?
wire eyelid speculum
Tx - FB under the TE
- TA (proxymetacaine CI with ulcers, also for short term use only as epitheliotoxic)
- topical AB (chloramphenicol, Fucithalmic)
- Should heal quickly once FB removed if otherwise healthy surface and no irritants remain
Tx - TE trauma
- heals quickly on own if healthy
- ulcers can form
- can suture with 6-0 vicryl but debride first, magnify, small round bodied needle, requires specialist skills and equpment
What is 'cherry eye'?
Prolapsed gland of the TE
Describe cherry eye/ TE gland prolapse
- produces 30% aqueous tear film
- unilateral or bilateral
- young dogs
What is conjunctivitis - follicular?
- an irritant, primary eyelid / TE problem
- very common in young dogs
- allergic response to environmental allergens
- in TE mostly, eyelid side less obvious, bulbar side most obvious
- horses and stalled animals (dust, flies)
Tx - conjunctivitis - follicular
- avoid and protect (preservative-free, viscous, lubricant)
- topical anti-inflammatory (steroid, no AB, short term)
- sodium chromoglcate (mast cell stabiliser - tricky as must be used before degranulation)
List 2 primary infectious causes of conjunctivitis
- CHLAMYDOPHILA: young cats, uni/bilateral, VERY hyperemic conjunctivitis, Tx with doxycycline for 21-28d, response starts after 4-5d but don't use in pregnant queens or kittens, swab to confirm
- FHV-1: more of a cornea problem but affects conjunctiva secondarily
Primary infectious causes of conjunctivitis in large animals,
- IBR: signs in adults are URT red nose and ocular (redness, dryness), different signs if in utero --> ocular developmental problems
- MORAXELLA BOVIS (= pink eye): fomites, typically seasonal, very hyperemic conjunctivitis
- LISTERIA MONOCYTOGENES (= silage eye): fomites, typically seasonal
What is corneal LPI?
Corneal lymphoplasmacytic infiltrate = pannus = CSK = Chronic Superficial Keratitis
- causes conjunctivitis
- 2 types: cornea only, TE and cornea, TE only (= LPI of the TE, aka plasmoma)
* Cats = EK = eosinophilic keratitis and keratoconjunctivitis in cats*
Name 3 follicular problems that cause primary eyelid/ TE irritation
- distichiasis = dogs and cats
- trichiasis = breeds with prominent and hairy facial features and/or long hair near the eyes
- ectopic cilium = dogs and horses
Tx - trichiasis
*cut hair short*
+/- remove prominent feature if possible (nasal fold)
Tx - distichiasis
*electrolysis for multiple hairs
* wedge resection for single hairs
Tx - ectopic cilium
* wedge resection
Outline primary eyelid/ TE neoplasias in dogs
* commonly benign (75-90%)
- meibomian gland adenoma and papilloma are commonest
- MCTs (may be less aggressive in the eyelid)
Outline primary eyelid/ TE neoplasias in cats
* variable, most malignant
Outline primary eyelid/ TE neoplasias in horses/cattle
* most are malignant
- SCC - potentially v serious (locally recurring and mets)
Define wedge resection
= removal of a full thickness wedge of eyelid, allows for removal of small eyelid mass
- eyelid left should allow for closure without tension (i.e. up to 25% of eyelid length but variable: cocker/chihuahua, dogs/horses)
What is a house resection?
= a modification of a wedge resection, it allows for slightly better closure of the resections in the larger end, doesn't provide additional tissue to the eyelid, large resections will require complex reconstruction, only works in some cases, relieves tension
Describe the closure of a wedge resection
In two layers:
1. an internal tarsal plate suture
2. figure of 8 suture
What is upper eyelid agenesis?
- affects cats
- lateral upper eyelid missing (eyelid coloboma)
- leads to trichiasis
- requires reconstruction (REFER)
a gap in part of the structures of the eye
List conformational problems of the primary eyelid / TE
- upper eyelid agenesis (cats)
Where can entropion occur? (think entropion chart)
- MEDIAL LOWER EYELID +/- CANTHUS
- UPPER EYELID
- LATERAL UPPER AND LOWER EYELID AND LATERAL CANTHUS
- LATERAL LOWER EYELID
Which animals are prone to medial lower eyelid +/- medial canthus entropion?
- high prevalence in pugs
Which animals are prone to upper eyelid entropion?
- cockers and hounds
- heavy ears and forehead, cause in-turning of upper eyelid
Which dog breed suffers from lateral upper and lower eyelid and lateral canthus entropion?
Which animals suffer from lateral lower eyelid entropion?
- young dogs of medium-big size
- young and old cats (--> fat loss --> eyes sink in)
- blepharospasm (cause/worsen entropion)
What can inturned hairs from eyelid cause?
Tx - Entropion
- amount to remove depends on severity (measure the pinch or roll-out method, always measure after TA to remove the spastic component)
- suture with 6-0 absorbable material following 'rule of bisection = first at either end and then half the distance until it is all closed)
- possibly with wedge resection (long eyelids leading to in-turning)
Tx - ectropion
possibly with wedge resection (long eyelids leading to overhanging)
T/F: primary eyelid/ TE repair should only be done for medical reasons
Name intraocular sources of irritants
- spasm (CB mm and iridal mm)
- miosis and photophobia
CAUSES: various intraocular dz (glaucoma, uveitis), prolonged or intense corneal stimulation causing a reflux uveitis
What is 'reflux uveitis'?
when iris mm go into spasm (atropine tx will help)
How painful is retrobulbar dz?
can be very painful