The red eye Flashcards
What are the steps to follow when thinking a case of red eye through?
- what where and how redness occurs in this particular case
- investigations that may be needed
- tx plan
Where are the different possible rednesses in the eye?
redness of ocular adnexa and cornea/sclera
iris hyperaemia
intraocular bleed
How can the area of the eye become red?
consider whole globe and adnexa
outside to inside
what structures are in the tissue i’m thinking of?
how would the tissues respond to insult?
how would changes in one tissue affect other tissues around it?
can this be a normal variation for this patient?
can any structures i can’t see be involved?
ocular vs systemic
Where, what and how can eyelids be red?
where: red periocular tissue
what: skin, muscles, meibomian galnds, conjunctiva
how: hyperamia, swelling, ulcers, crusts, loss of hair, etc.
What are common causes of red eyelids?
periocular dermatitis (many causes, some systemic and potentially severe)
meibomian glands (can become infected, inflamed, neoplastic)
How can abnormal eyelids affect the cornea and the tear film?
loss of protective effect
loss of oily component of tears
abnormal contact: hair or masses contacting the ocular surface
What can abnormal eyelids lead to?
irritation of the white eye: conjunctival hyperaemia
corneal irritation: corneal neovascularisation and ulceration
Where and what can the third eyelid be red?
where: red ocular coats
what: cartilage, lymphoid tissue, accessory lacrimal gland
How can the third eyelid become red?
T shape cartilage holds up the third eyelid against the eye: can curl and cause and outward fold
large amount of lymphoid tissue (prominent in some cases) on the inner side and accompanied with hyperaemia
accessory lacrimal gland which produced 30% of aqueous component of tears can prolapse and become inflamed
What is the normal TEL?
some vasculature visible but minimal
variable pigmentation
What are potential causes for TEL hyperaemia and swelling?
ocular surface disease
orbital disease
TEL neoplasia
What is TEL follicular proliferation?
presence of multiple small “bubbles” on the external and internal TEL
seen in young animals, allergies, certain infections in cats
mainly present on inner side
usually accompanied with hyperaemia
Where what and how can the conjunctiva be red?
where: red ocular coats
what: mucous membrane lining eyelids, third eyelid, sclera, epithelium, goblet cells, lymphoid tissue, blood vessels
how: hyperaemia, swelling, ulcers, lymphoid follicles
What is conjunctival hyperaemia a sign for?
ocular surface disease
Where what and how can the episclera/sclera become red?
where: red ocular coats
what: fibrous tunic of the globe, collagen, blood vessels
how: hyperaemia and swelling
What is episcleral hyperaemia a sign of?
sign of deeper ocular tissues diseases (including intraocular)
What does the normal conjunctiva/sclera/episclera look like?
conjunctival vasculature is present but minimal
episcleral vasculature is rarely seen in normal conditions
What is the difference between conjunctival and episcleral hyperaemia?
conjunctival: sign of ocular surface disease, dichotomous division, superficial vessels that move with the conjunctiva, most evident in the fornixes
episcleral: sign of deeper ocular tissues disease, no division and dont move with the conjunctiva, most evident close to the limbus
How can you tell if there is conjunctival or episclera hyperaemia?
conjunctival: tortuous, branching, bright red, vessels move with conjunctiva, most evident at fornixes
episcleral: straight and deep red, vessels stationary, most evident closer to limbus
Where what and how can the cornea become red?
where: red ocular coat
what: anterior part of fibrotic tunic of the globe
how: corneal neovascularisation, +/- intracorneal bleed
What is superficial corneal neovascularisation a sign of and what does it look like?
sign of oculaar surface disease
dichotomous division, long and branching (like trees)
may occur with or without corneal ulceration
What is the difference between superficial and deep corneal neovascularisation?
superficial: sign of ocular surface disease, dichotomous division, long branching vessels
deep: sign of deeper ocular disease, short straight deep red vessels, usually stay close to the limbus and look like a bush
What is ulcerative keratitis and how is it diagnosed?
infection causing
- conjunctival hyperaemia
- superficial corneal neovascularisation
positive fluorescein stain
STT1 variable
What is keratoconjunctivitis sicca and how is it diagnosed?
dry eye causing
- conjunctival hyperaemia and ocular discharge
- superficial corneal neovascularisation
fluorescein stain variable
STT1 low
What is deep corneal neovascularisation a sign of?
sign of deep ocular tissues disease (including intraocular)
What are 2 causes for deep corneal neovascularisation?
uveitis
glaucoma
What are the signs of uveitis?
episcleral hyperaemia
deep corneal neovascularisation
small pupil (miosis)
low intraocular pressure
What are the signs of glaucoma?
episcleral hyperaemia
deep corneal neovascularisation
dilated pupil (mydriasis)
high intraocular pressure
What is intracorneal haemorrhage sign for?
relatively uncommon
always associated to corneal neovascularisations
can be associated to systemic disease (systemic hypertension)
Where and what in the aterior chamber or the vitreal cavity can be red?
where: intraocular bleed
what: in normal conditions there is aqueous humour but at the limits of the chamber there is the cornea, iris and iridocorneal angle
What are 4 possible abnormalities that could be found in the anterior chamber?
hyphema: blood
hypopion: WBC
aqueous flare: proteins
fibrinous uveitis: fibrin
How can the anterior chamber or the vitreal cavity become red?
inflammation (uveitis)
trauma (penetrating or blunt)
intraocular neoplasia
retinal detatchement
glaucoma
congenital defect
systemic condition (hypertension, thrombopathy, coagulopathy
Where what and how can the anterior uvea become red?
where: iris hyperaemia (iris rubeosis)
what: uveal vasculature, connective tissue, pigmentation
how: uveal bleed, tumour, engorgment of normal vessels, formation of new vasculature over iris surface
What are pre-riridal fibrovascular membranes?
PIFM
formation of new vasculature over the iris surface
secondary to uveitis, intraocular tumour, retinal detatchement or glaucoma
Where what and how can the posterior uvea/retina be red?
where: intraocular bleed
what: posterior uvea and retina (neuronal cells and retinal vacs.)
how: similar to anterior uvea, most common bleed from the retinal/choroidal vasculature
- some anatomical variations can mimic retinal/choroidal bleeds
Where and what in the retrobulbar space can be red?
where: red 3rd eyelid and red ocular coats
what: intraconal space (extraocular musculature, nerves and vessels), extraconal space (lacrimal and salivary glands, bone, teeth roots and other nerves and vessels)
How can the retrobulbar space be red?
any growing structure within the retrobulbar space (infl. infec. neopl.) will most likely deviate the globe as well as compromising the vascular return from the rest of orbital structures
some orbital conditions can be associated with orbital bleeds or can affect the globe causing an intraocular bleed
What tests are important to not forget in cases presenting with red eye?
STT1
fluorescein stain
IPO/tonometry
- be aware of contraindications for these tests
What cases of red eye contraindicate the use of STT1, fluorescein stain and tonometry tests?
corneal or scleral rupture
may present with red eye
patients should be minimally manipulated and treated as a fragile eye
What diagnostic tests are important when suspecting infectious keratitis?
corneal cytology
culture and sensitivity
What diagnostic tests are important when suspecting glaucoma?
gonioscopy (slit lamp used to evaluate the eye’s drainage angle)
What diagnostic tests are important when suspecting uveitis?
systemic investigations
ocular ultrasound
What diagnostic tests are important when suspecting retrobulbar disease?
MRI/CT
What does a tx plan in gp look like?
give diagnosis and advise when possible
tx what you feel confident about
refer to a specialist when necessary
When to refer or consult with an eye specialist?
when not confident in dx or tx plan
when not able to perform a complete ophtalmic exam
when there is risk of losing the eye or the sight
complex cases or cases requiring further investigation
