the conjunctiva Flashcards
name the three layers of the conjunctiva?
- PTF (precorneal-preconjunctival tear film)
- Epithelium (with mucus producing goblet cells)
- substantia propria (immunological process)
describe the vessels supplying the conjunctiva?
prolific arterial blood supply
coming from the peripheral marginal eyelid and anterior ciliary arteries
1. superficial conjunctival vessels
2. deep conjunctival vessels
forms of conjunctival injections?
- conjunctival flush
2. ciliary flush
what indications are there for conjunctival injections?
conjuntivitis
what are the indications for pericorneal injections?
rosacea
corneal lesions near the limbus
foreign body
herpetic keratitis
what are the indications for ciliary injection?
Episcleritis scleritis disciform keratitis iritis cyclitis
what is a conjunctival dermatoid?
ectopic skin tissue in conjunctiva
congenital circumscribed overgrowth of microscopically normal tissue in an abnormal place
aetiology of conjunctival dermatoid?
developmental abnormality (inherited in hereford cattle)
treatment of conjunctival dermatoid?
surgery
- careful surgical conjunctivectomy and dissection down to bare sclera
- if the lesion extends into the cornea, combined conjunctivectomy and keratectomy
- new lateral cants created through H-plasty
what is symblepharon?
permanent adhesion between adjacent conjunctival surfaces or between the conjunctiva and cornea
in what species is symblepharon common?
young cats (foals)
signs of symblepharon?
adhesions, cornea is covered by conjunctiva, inhibition of movement of the eyelids, inadequate widening of the palpebral fissure, impaired vision
treatment of symblepharon?
complete US prior to surgery to assess the status of eyeball
remove adhesion from ocular surface
what is conjunctivitis?
inflammation of the conjunctiva
name the two types of conjunctivitis?
- primary: without involvement of other ocular structures
2. secondary: sequel or other ocular or systemic systemic inflammation
causes of primary conjunctivitis?
bacterial viral fungal parasitic allergic chemical traumatic
appearance of primary conjunctivitis?
serous mucoid mucopurulent purulent haemorrhage follicular
clinical signs of conjunctivitis?
hyperaemia chemosis (bulging) discharge haemorrhage follicle-formation (uneven surface) Pruritis
treatment of bacterial conjunctivitis?
topical, subconjunctival, and systemic ABs; topical NSAIDs
(diclofenac, chloramphenicol, tobramycin, ciprofloxacin)
warm compress and cleaning
description of ocular thelasiasis?
Parasite: thelazia causing conjunctivitis
transmitted by flys
treatment of ocular thelasiasis?
manual removal of the parasites
systemic anti-parasitic agents:
- Milbemycin
topical anti-parasitic agents:
- ivermectin
when would you use special eyewash (EDTA)?
chemical conjunctivitis
causes of conjunctivitis in cats?
- herpes virus
- chalamydia virus
- mycoplasma
diagnosis of conjunctivitis in cats?
difficult (PCR could be useful)
treatment of herpes-conjunctivitis?
Famciclovir PO, ganciclovir drops, interferon PO/ drops, L-lysine PO
efficacy is questionable
occurrence of tumours on conjunctiva?
in animals with hypo pigmented conjunctive are easily affected by the suns UV rays
tumour development in cattle?
SCC (irregular surface) caused by hypo pigmentation and UV light effect
tumour development in dogs?
Papilloma (virus) melanoma fibroma fibrosarcoma haemangioma haemangiosarcoma
treatment of tumours in LA?
depends on the value of the animal usually extirpation (complete removal of the organ)
tumour treatment in small animals?
surgery (H plasty)
oncotherapy
enucleation
