Ophthalmology 5: Problem Solving - The Red Eye Flashcards
Which structures of the eye could go red?
Conjunctiva, sclera, cornea, mass, eyelids, iris, cherry eye, anterior chamber.
What pathology could make the anatomy of the eye look red.
Inflammation/hyperaemia, haemorrhage/clotting problems, trauma, vascularisation.
What is the top cause of a red eye?
Conjunctivitis.
What can look like a red eye?
Eyelids, third eyelid, conjunctiva (sub-conjunctival haemorrhage, hyperaemia or chemosis, mass or thickening), cornea (vascularisation, cell infiltrate, granulation, haemorrhage), iris (mass, haemorrhage), anterior chamber - hyphaema.
Is a red eye an emergency?
Difficult to tell over the phone so best to assess the same day.
Red eyelids - causes.
Periocular dermatitis.
Blepharitis (Meibomian gland disease and impaction, infected meibomian glands).
Eyelid masses.
Blunt trauma.
Other injuries.
Insect bite reactions.
Cat bite abscess.
Minimum ophthalmic database for every case?
Schirmer tear test.
Fluorescein.
Tonometry (if available).
Neuro-ophthalmic tests (PLR/Menace/Dazzle/Palpebral).
Swabs and culture / cytology.
Biochemistry / haematology.
Schirmer tear test.
Quantitative.
Sterile graduated filter paper strips.
Later lower fornix for 1 min.
Normal reading in dogs = 15-25mm/min.
Measures basal + reflex production.
How can we assess the vision of a patient?
Movement in novel environment (maze test).
- carry out in light and dark.
Menace response.
Visual tracking (cotton ball).
Visual placing - to edge of table.
What would be the main reason a 10yo MN cross breed dog presents w/ bilateral red eyes?
Keratoconjunctivitis Sicca.
Typical signs to look for in KCS?
Mucus string.
Pigmentation.
Stippled/dull corneal reflection.
Reduced STT.
Ocular pain (dryness).
Hyperaemia.
How would KCS be treated?
Ciclosporin ointment.
Lubricants e.g. hyaluronate, carbomer.
Dexamethasone drops - as anti-inflammatory, NOT LONG-TERM – more likely develop ulcers and reduce host response and resistance to infection.
Fusicid acid gel IF SECONDARY INFECTION - SHORT TERM.
Steroid and AB drops - at dx, not long term.
Common eyelid tumours?
Meibomian gland tumours.
Melanoma.
Squamous cell carcinoma (horses, cats, farm).
Mast cell tumours (appropriate to stage before excision).
Histiocytoma.
Sarcoid in horses.
Lipoma.
Papilloma.
Mainly locally aggressive so removing while small always better.
One referral approach to red eyelid/s?
- Identify any mechanical irritation - self (pruritic)/lids/hairs/discharge.
– best in relaxed and unrestrained patient. - Search for dermatophytes and parasites (tape strips / plucks).
- Eyelid infection present? (meibum culture / skin cytology).
- Consider irritants / skin allergy last (speak to dermatologist?)
- Biopsy eyelid if ulcerated, masses or persists in face of tx.
- How is the 3EL kept structurally firm?
- Other names for 3EL?
- T-shaped hyaline cartilage in it, stabilising the leading edge of the 3EL.
- Nictitans/ nictitating membrane.
Causes of 3EL protrusion?
Enophthalmos.
Microphthalmos.
Exophthalmos.
Inflammation of 3EL.
Neoplasia of 3EL.
Horner’s syndrome.
Scrolled cartilage of the 3EL.
Prolapsed gland of 3EL (cherry eye).
Prolapse of 3EL gland - cherry eye.
Primary condition.
Uni or bilateral.
Young dogs.
Red, homogenous mass arising from bulbar aspect of 3EL.
Irritation > inflammation > ulceration w/ continued exposure.
Main breeds affected by cherry eye.
Neapolitan mastiffs.
English bulldog.
Cane Corso.
American cocker.
Lhasa Apso.
French bulldog.
St Bernard / Great Dane / Newfoundland.
Treatment of cherry eye?
DO NOT REMOVE GLAND - can cause 2’ KCS.
Medical Tx.
- reduce inflammation w/ topical or systemic NSAID.
- control 2’ infection w/ topical 1st line AB.
Manual re-positioning of gland - recurrence common.
Corrective Sx usually required.
3EL gland Sx.
Modified ‘Morgan’ Pocket technique. ‘
- Bury the gland in conjunctival pocket.
- Microsurgical instruments.
- Magnification (x3-5).
- Microsurgical absorbable braided suture:
– 5-0 or 6-0. e.g. polyglactin910.
- Knot on palpebral aspect of 3EL.
- Approximately 80% success.
Anchoring techniques also exist.
What is the key to resolving a conjunctivitis?
Working out what has gone wrong in the lacrimal unit to cause the conjunctivitis.
e.g. tear production, tear film removal, immunologic protection of the eye (CALT), ocular movement, corneal healing, mechanical protection.
What diseases can conjunctivitis be present alongside?
Corneal disease - oedema, keratitis, corneal ulceration.
Intraocular - uveitis, glaucoma.
Causes of conjunctivitis.
Irritants/chemicals/ drugs (environment).
Abnormal eyelid conformation (entropion etc).
Aberrant hairs (trichiasis/districhiasis/ectopic cilia).
KCS.
Inflammation extending from proximal tissues.
Trauma/FB.
Corneal or intraocular disease.
Systemic conditions (systemic hypertension / coagulopathy).
Normal increased cranial perfusion in light coloured dogs due to excitement or temp. change.
Differential diagnoses for surface ocular disease.
F - FB.
A - Allergic (drugs / environment).
T - Trauma / toxins.
T - Tear film deficiency - quant, qual, drainage, distribution.
I - Infectious, Immune-mediated.
M - Mechanical irritation – lids, hairs, irritants (soap/wind/sand/fumes/meds).
E - Eyelid – blepharitis extends to conjunctiva.
T - Tumour – infiltrating conjunctiva.
