Conjunctivitis, KCS and NL system Flashcards
1
Q
What are the six causes of red eye?
A
- G – glaucoma
- O – orbital disease
- S – scleritis/episcleritis
- U – uveitis
- C – conjunctivitis
- K – Keratitis
2
Q
What are the clinical signs of conjunctival disease?
A
- Conjunctival hyperemia
- Ocular discharge
- Chemosis
- Follicular hyperplasia
- Conjunctival masses
3
Q
Which is more common: primary or secondary conjunctivitis?
A
- The conjunctivitis is often the innocent bystander
- Primary conjunctivitis is much less common than secondary conjunctivitis
4
Q
What are some etiologies of conjunctival disease?
A
- Infectious - viral, bacterial, parasitic, fungal
- Immune mediated
- Toxic or chemical or traumatic
- Tear film abnormalities
- Frictiona - exogenous: FB, dust, smoke, wind; endogenous: tear film defect, entropion, ectropion and lagophthalmos
5
Q
What are some differential diagnosis of conjunctival diseases?
A
- GOSUCK - must rule out all other disease
- Due to another blinding ocular disease
6
Q
What are some etiologies of primary conjunctivitis?
A
- Cats and ruminants - primary infectious agents
o Cats: C felis, FHV, mycoplasma
o Cows: IBR, Moraxella
o Sheep/goats: Chlamydophila, mycoplasma - Dogs and horses - rarely infectious but DDX should include:
o Dogs: distemper, adenovirus, herpes virus
o Horses: EHV, Onchocerca cerrvicalis
7
Q
How do we diagnose conjunctival disease?
A
- Conjunctival biopsy/scrapings
- Bacterial culture - rarely recommended
8
Q
What are the 4 common causes of conjunctivitis in cats?
A
- Feline Herpes virus
- Chlamydophila felis
- Mycoplasma
- Eosinophilic keratoconjunctivitis
9
Q
Describe FHV induced conjunctivitis?
A
- Most common cause of conjunctivitis and keratitis is cats
- Ubiquitous virus
- Primary inoculation of oral, nasal or conjunctival mucosa
o Primary disease is usually self-limiting
o Typical in kittens leading to bilateral disease - Life long latency develops within the trigeminal ganglia (80%)
- Throughout life episodes of reactivation may be stimulated by stress or even administration of steroids
o Adults - unilateral, unassociated with systemic signs, milder but chronic
10
Q
What is the pathognomic sign of FHV conjunctivitis?
A
- Dendritic ulceration of the cornea
11
Q
How do you diagnose FHV?
A
- Clinical signs
- PCR - beware of FP or FN
12
Q
How do you treat FHV?
A
- Supportive
- Mild conjunctivitis does not require treatment
- Oral L-lysine 500mg BID adults (half the dose in kittens)
- Severe conjunctivitis or keratitis
o Topical anti-viral or oral anti-viral BID for 14 days with topical antibiotics if ulcers are present
13
Q
What are the clinical signs for C. felis conjunctivitis?
A
- Bilateral Chemosis - most prominent
- Possible sequestration of bacteria in non-ocular sites (GIT)
14
Q
How do you diagnose C. felis infection?
A
- PCR or cytology
o Looking for intracytoplasmic elementary bodies in the epithelial cells
15
Q
How do you treat C. felis infection?
A
- Topical antibiotics - fluoroquinolones
- Systemic antibiotics - doxycycline or azithromycin
16
Q
What is feline eosinophilic keratoconjunctivitis?
A
- Proliferative conjunctivitis with or without keratitis
17
Q
How do you diagnose EKC?
A
- Cytological scrapings or biopsy of the lesions
o Looking for mast cells or eosinophils
18
Q
How do you treat EKC?
A
- Topical corticosteroids
19
Q
Describe canine follicular conjunctivitis.
A
- Likely the most common cause of primary conjunctivitis in dogs
o Typically young dogs
o Due to unknown antigenic stimulation
20
Q
How would you diagnosis CFC?
A
- Clinical signs - follicles on the conjunctiva
21
Q
How do you treat CFC?
A
- Usually self-limiting generally does not require treatment
- Can use eye-wash, lube +/- topical steroids if recurrent or non-resolving
22
Q
What are the components of the lacrimal system?
A
- Lacrimal puncta
- Lacrimal gland
- Lacrimal sac
- Canaliculi
- Nasolacrimal duct
- Nasal punctum
23
Q
What are some lacrimal diseases?
A
- Inability to produce normal tears
o Quantitative abnormality - insufficient aqueous component to tears = KCS
o Qualitative abnormality - abnormal mucus or lipid component to tears - Inability to drain tears
o Obstruction within the lacrimal system
24
Q
What is Keratoconjunctivitis sicca (KCS)?
A
- Deficiency of aqueous tear production
25
What are the pathological changes associated with KCS?
- Tear film becomes more hypertonic which dehydrates the corneal and conjunctival epithelium
- Leads to edema, friction, epithelium keratinization, vessel infiltration
26
What are the clinical signs of KCS?
- Dry, lusterless cornea
- Mucoid and mucopurulent discharge
- Blepharospasm
- Corneal ulceration
- Corneal vascularization and pigmentation (if chronic)
27
What are the etiologies of KCS?
- Immune mediated destruction of the lacrimal gland **most common**
- Congenital - no gland or small gland
- Drug induced - TMS
- Infectious - CDV
- Neurogenic - denervation
- Orbital trauma
- Alkali or acid burns to the conjunctiva
28
How do you diagnose KCS?
- Clinical signs
| - Schirmer tear test
29
How do you treat KCS?
- Lacrimostimulants FOR LIFE
o Topical cyclosporine
- Lacrimomimetics
o Teargel, lacrilube
30
What is the prognosis of a patient with KCS?
- Good if early dx and STT >2mm/min
31
How do you treat neurogenic KCS?
- Oral pilocarpine to stimulate lacrimal gland
32
How do you treat refractory or congenital KCS?
- Parotid duct transposition
33
What are qualitative tear film disorders?
- Deficiency in lipid (from Meibomian gland) or mucin (goblet cells)
34
What are the etiologies for qualitative tear film disorders?
- Severe blepharitis
- Conjunctivitis
- Idiopathic
35
How do you dx qualitative tear film disorders?
- Tear film breakup time
| * **similar pathology, clinical signs and treatment as with KCS***
36
What are nasolacrimal disease?
- Lack of patency or inflammation
37
What are the clinical manifestations of NL disease?
- Epiphora
- Punctal discharge
- Punctal FB
- Swelling of the ventral medial canthal region
- Draining fistulas
38
How do you diagnose NL disease?
- Schirmer tear test >25mm/min
- Fluorescein dye passage test - 3-5 mins
- Punctal cannulation and lavage
o Normograde - small animals
o Retrograde - horses
o Culture and sensitivity
- Imaging - confirm and determine the extent of disease
o Plain radiographs
o Dacryocystorhinography
o CT/MRI
39
What are some congenital causes of NL disease?
- Lacrimal punctal atresia
- Atresia of canaliculus, NL sac and or NL duct
- Cysts - canaliculops, dacryops
40
What is the main cause of congenital NL disease in large animals?
- NL puncta atresia - common in horses, alpacas and llamas
41
When do the clinical signs of NL puncta atresia occur?
- 2-16 weeks of age
| o Epiphora and mucopurulent ocular discharge
42
How do you diagnose NL puncta atresia in large animals?
- Clinical exam, NL lavage and contrast radiography
43
How do you treat congenital NL puncta atresia?
- Incision into the duct
- Cannulate for several weeks
- Antibiotics and steroids
44
What are common acquired NL diseases?
- Dacryocystitis inflammation of lacrimal sac and duct which narrows the lumen of the duct and strictures form
- Trauma/laceration
45
What causes dacryocysitis?
- Usually secondary to FB in the lacrimal duct
- External compression - tooth root abscess, neoplasia, inflammation
- Osteomyelitis
- Thelezia sp in large animals
46
How do you diagnose dacryocysitis?
- Clinical exam
- NL lavage
- Dacryocystorrhinography
- Cytology
- Biopsy of tissue
- Culture
- Surgical exploration
47
How do you treat dacryocysitis?
- Requires treatment of underlying disease to resolve
| o REFER - flushing of the NL system; dacryocystostomy followed by stent placement and antibiotic therapy
48
How do you treat trauma/laceration induced NL disease?
- REFER - microsurgical apposition and cannulation
