Conjunctiva and KCS Flashcards
What is the anatomy of the conjunctiva?
- Thin, transparent pink mucous membrane
- Starts at limbus (junction between cornea and sclera)
- Covers the globe itself – bulbar conjunctiva
- Lines inner aspects of upper/lower eyelids - palpebral conjunctiva
- Space between is conjunctival sac
- Lines both sides of third eyelid
Label
- Dorsal fornix
- Bulbar conjunctiva
- Palpebral conjunctiva
- Upper eyelid
- Lower eyelid
- Third eye lid
Of the conjunctiva, what is the:
A) Vascular supply?
B) Nerve supply?
A) Rich
B) Sparse
What provides the lymphatic drainage of the conjunctiva?
CALT = Conjunctiva-Associated-Lymphoid- Tissue
What is the mobility of the conjunctiva?
•Freely mobile apart from attachments at limbus and eyelid margin
Name 4 clinical signs of Acute conjunctivitis (6)
- Unilateral or bilateral
- Hyperaemia (conjunctival redness)
- Chemosis (oedema of conjuctiva)
- Swelling or thickening
- Mild irritation, e.g. mild blepharospasm
- Discharge
–Lacrimation
–Mucoid, purulent, mucopurulent, haemorrhagic
•(Pruritus, e.g allergic conjunctivitis)
What is seen with this acute conjunctivitis?
- Hyperaemia
- Mild chemosis
- Serous discharge
What is this? Give an example of a cause
Chemosis e.g. allergy
Which breed is commonly affected by this? What is it?
Shar Pei dogs are frequently affected with mucinosis
What is the term for deep set eyes?
Enophthalmos
What is ‘medial canthal pocket syndrome’? Where is it “normal”?
•Mucus accumulates at medial canthus
Dolichocephalic breeds
What is this?
‘medial canthal pocket syndrome’
Name 3 clinical signs of Chronic conjunctivitis (4)
- Hyperaemia, discharge etc as for acute conjunctivitis
- Thickening (squamous metaplasia of epithelium) of conjunctiva
- Hyperpigmentation
- Follicular hyperplasia
What can be seen here?
Chronic conjunctivitis
Palpebral is pigmented
Thickened
Hyperpigmented
(upper is inverted)
What can be seen here?
Follicular hypertrophy
See all follicles
Where is it normal for some species to have a patch of follicles?
Back of third eyelids
What are the 5 types of canine conjunctivitis?
- Infectious
- Non-infectious
- Extension from local disease
- Secondary to another ocular disease
- Secondary to systemic disease
What is the most common type of infectious conjunctivitis?
Secondary
What is the common bacterial infection cause of (secondary) infectious conjuctivitis?
–Commensal Gram +ve organisms, e.g. Staphylococcus sp, Streptococcus sp
Name a viral infection which may cause infectious conjunctivitis?
Canine herpes 1
Name a paratie infection which may cause infectious conjunctivitis?
How would you find it?
Thelazia
–Worm living behind third eyelid
–Think about the rescue dogs coming in
–Look behind the 3rd eyelid with forceps
What is this?
Bacterial conjunctivitis
(purulent discharge)
Name 6 underlying causes for conjunctivitis (9)
- Eyelid problem, e.g. entropion, ectropion
- Eyelash problem, e.g. distichia, ectopic cilia
- Tear film problem, e.g. dry eye
- Tear duct infection (dacryocystitis)
- Trauma, e.g. FB, laceration
- Allergic e.g. atopic dermatitis
–If it does have skin disease they are probably linked
- Irritants e.g. smoke, sand, neomycin
- Ligneous conj’itis in Dobermann
- Radiation-induced
What is this?
Entropion - eyelid turns in
How would you treat entropian?
Hotz-Celsus: removal of elliptical piece of skin and evert the eyelid
What is this?
Ectropion - everted eyelid
What are each of these?
A) Normal
B) Distichia
C) Ectopic cilia
What is this?
Distichiasis - extra eyelashes
What is this?
Ectopic cilia – Pain! Everted upper to show
just one will cause discomfort
What does this show?
Subconjunctival haemorrhage.
Name 2 things conjunctiva might be affected by (3)
- Blepharitis (eyelid inflammation)
- Lacrimal disease, e.g. ‘cherry eye’ (prolapse of third eyelid gland)
- Orbital disease, e.g. retrobulbar abscess
Other than conjuctivitis, name 2 causes of a red eye (3)
–Uveitis
–Glaucoma
–Scleritis/episcleritis
Name 4 systemic diseases which involves the conjunctiva (6)
–Anaemia
–Jaundice
–Coagulopathy
–Neoplasia,e.g. lymphoma
–Auto-immune disease
–Systemic hypertension
Name 2 diagnostic approaches to diagnosing canine conjunctivitis to examine the pertinent parts of the eye exam (4)
- Eyelid conformation and eyelid margins
- Tear production
–Schirmer tear test
• Fluorescein dye application
– Check for corneal ulcer
– Assess patency of tear duct
• General examination including skin
How do we treat canine conjuncitivits?
- Treat/remove underlying cause
- Topical antibiotic therapy
–Fusidic acid (Isathal®)
- First choice in the UK
- Treats Gram +ve organisms most commonly found in canine conjunctivitis (Staph’ sp, Strep sp)
–Chloramphenicol drops/ointment
–Other antibiotics based on culture & sensitivity
What is Keratoconjunctivitis sicca?
•Immune-mediated destruction of lacrimal tissue
Label
a = lacrimal gland (dorsolateral orbit)
b = third eyelid gland (nictitans gland);
Name 5 causes of dry eye in the dog (6)
- Immune-mediated MOST COMMON CAUSE
- Congenital
–Lacrimal gland aplasia/hypoplasia
•Neurogenic
–Unilateral, dry eye/dry nose
•Toxic
–Sulphonamide drugs
•Endocrine disease
–Diabetes mellitus, hypothyroidism
•Iatrogenic
–Removal of third eyelid gland
How can you diagnose KCS?
- Schirmer tear test (STT)
- Quantitative measurement of tear production
- Measures aqueous part of tear film (3 parts)
- Measures basal and reflex tear production
–Reflex tear production is in response to sensation of paper strip in contact with cornea, therefore placement of strip in eye is important
What is a diagnostic STT for KCS?
0-10 mm/min
What makes us suspect KCS?
Conjunctivitis & tenacious discharge
Discharge stick to the surface
Eye is dry
What is the difference in discharge betwen dry eye and a dog with normal tear production?
Dry eye - discharge adheres to cornea
Normal producton - collects around eyelid
How do you treat KCS?
- Lifelong therapy - control not cure
- Tear substitutes
–Various false tear preparations in eye drop, gel or ointment formulation
•Tear stimulants (lacrimogenic)
–Cyclosporine 0.2% (Optimmune)
•Broad spectrum topical antibiotic to treat secondary e.g. Staphylococcal sp infection
What is cherry eye?
Prolapse of third eyelid gland
Cherry eye:
A) What age is affected?
B) Name 2 common breeds
A) <1yo
B) Bulldog, Lhasa Apso, Shih Tzu, ACSp, Mastiff breeds
What is this?
Cherry eye
How can we treat cherry eye?
•Surgical replacement
–‘pocket’ technique
–tacking procedures
What are the 2 causes of feline infectious conjunctivitis?
–Chlamydia
–Herpes
What are the 5 agents of bacterial conjunctivitis. Highlight the most important
1.Chlamydophila felis (bacterium)
2.Feline herpesvirus-1 (FHV-1) (virus)
- Feline calicivirus (FCV)
- Mycoplasma felis (bacterium)
- Bordetella bronchiseptica (bacterium)
Name clinical signs of Chlamydophila felis
–Unilateral conjunctivitis, becomes bilateral within a few days
–Chemosis often marked, hyperaemia
–No corneal signs
•Differentiate from herpes
–Absent or mild upper respiratory disease
•Not generally coughing or sneezing
What do we suspect?
Chlamydophila felis
How do we diagnose C. Felis?
- Clinical signs (non specific)
- Conjunctival swab for PCR test
- PCR has superseded culture
How do we treat C. Felis?
- Systemic treatment indicated as organism affects respiratory tract, GIT and reproductive tract as well as eye
- Doxycycline antibiotic of choice
–5mg/kg bid or 10mg/kg sid for three weeks
–NB teeth discolouration and oesophagitis
•Amoxycillin-clavulanate in pregnant queen or kittens
What are the clinical signs of Feline Herpesvirus 1 by age?
•Kittens and young cats
–Bilateral conjunctivitis in conjunction with upper respiratory signs (cat flu)
–+/- corneal ulceration
•Adult cats
–Unilateral ocular discharge with mild conjunctivitis
–History of previous upper respiratory infection
–Wide range of other conditions, e.g. sequestrum, entropion, eosinophilic keratitis
What is this and how do we know?
Dendritic corneal ulcer
Uptake – virus tracking along epithelium and chlamydia has not tropism for corneal epithelium – KNOW this is herpes as nothing lse does this
How can we diagnose FHV 1?
- History and clinical signs
- Conjunctival swab for PCR test
–Same technique as for C felis
–Swab site of interest i.e. swab cornea, conjunctiva and/or oropharynx
•PCR has superseded culture (like C felis)
How can we treat FHV 1?
•Nursing
–Cleaning eyes, nutrition, rehydration
–Supportive
–Kittens can easily get dehydrated
•Broad-spectrum antibiotic to prevent/treat secondary bacterial infection
–Topical for eyes (e.g. fusidic acid, chloramphenicol)
–Systemic for respiratory involvement e.g. amoxycillin-clavulanate
–Reason behind this – prevent secondary
•Anti-virals
–Topical e.g. ganciclovir
–Systemic e.g. famcyclovir (fairly expensive)
–Expensive and hard to obtain
–Reserve for persistence
Give clinical signs of feline calcivirus
- Upper respiratory disease, oral ulceration, polyarthritis
- Conjunctivitis
Mycoplasma sp:
A) Where is it seen?
B) How do we diagnose?
C) How do we treat?
A) Normal cats
B) PCR
C) Topical antibiotics
Bordetella bronchiseptica:
A) What gram??
B) What is affected?
C) What is the risk?
D) How do we diagnose?
E) Name a treatment option
A) Negative
B) Respiratory tract s
C) Dogs infect cats
Zoonosis
D) Culture and/or PCR
E) Doxycycline
