Ophthalmology 5: Problem Solving - The Red Eye

Question 1

Which structures of the eye could go red?

Answer 1

Conjunctiva, sclera, cornea, mass, eyelids, iris, cherry eye, anterior chamber.

Question 2

What pathology could make the anatomy of the eye look red.

Answer 2

Inflammation/hyperaemia, haemorrhage/clotting problems, trauma, vascularisation.

Question 3

What is the top cause of a red eye?

Answer 3

Conjunctivitis.

Question 4

What can look like a red eye?

Answer 4

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.

Question 5

Is a red eye an emergency?

Answer 5

Difficult to tell over the phone so best to assess the same day.

Question 6

Red eyelids - causes.

Answer 6

Periocular dermatitis.
Blepharitis (Meibomian gland disease and impaction, infected meibomian glands).
Eyelid masses.
Blunt trauma.
Other injuries.
Insect bite reactions.
Cat bite abscess.

Question 7

Minimum ophthalmic database for every case?

Answer 7

Schirmer tear test.
Fluorescein.
Tonometry (if available).
Neuro-ophthalmic tests (PLR/Menace/Dazzle/Palpebral).
Swabs and culture / cytology.
Biochemistry / haematology.

Question 8

Schirmer tear test.

Answer 8

Quantitative.
Sterile graduated filter paper strips.
Later lower fornix for 1 min.
Normal reading in dogs = 15-25mm/min.
Measures basal + reflex production.

Question 9

How can we assess the vision of a patient?

Answer 9

Movement in novel environment (maze test).
- carry out in light and dark.
Menace response.
Visual tracking (cotton ball).
Visual placing - to edge of table.

Question 10

What would be the main reason a 10yo MN cross breed dog presents w/ bilateral red eyes?

Answer 10

Keratoconjunctivitis Sicca.

Question 11

Typical signs to look for in KCS?

Answer 11

Mucus string.
Pigmentation.
Stippled/dull corneal reflection.
Reduced STT.
Ocular pain (dryness).
Hyperaemia.

Question 12

How would KCS be treated?

Answer 12

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.

Question 13

Common eyelid tumours?

Answer 13

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.

Question 14

One referral approach to red eyelid/s?

Answer 14

1. Identify any mechanical irritation - self (pruritic)/lids/hairs/discharge.
   – best in relaxed and unrestrained patient.
2. Search for dermatophytes and parasites (tape strips / plucks).
3. Eyelid infection present? (meibum culture / skin cytology).
4. Consider irritants / skin allergy last (speak to dermatologist?)
5. Biopsy eyelid if ulcerated, masses or persists in face of tx.

Question 15

1. How is the 3EL kept structurally firm?
2. Other names for 3EL?

Answer 15

1. T-shaped hyaline cartilage in it, stabilising the leading edge of the 3EL.
2. Nictitans/ nictitating membrane.

Question 16

Causes of 3EL protrusion?

Answer 16

Enophthalmos.
Microphthalmos.
Exophthalmos.
Inflammation of 3EL.
Neoplasia of 3EL.
Horner’s syndrome.
Scrolled cartilage of the 3EL.
Prolapsed gland of 3EL (cherry eye).

Question 17

Prolapse of 3EL gland - cherry eye.

Answer 17

Primary condition.
Uni or bilateral.
Young dogs.
Red, homogenous mass arising from bulbar aspect of 3EL.
Irritation > inflammation > ulceration w/ continued exposure.

Question 18

Main breeds affected by cherry eye.

Answer 18

Neapolitan mastiffs.
English bulldog.
Cane Corso.
American cocker.
Lhasa Apso.
French bulldog.
St Bernard / Great Dane / Newfoundland.

Question 19

Treatment of cherry eye?

Answer 19

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.

Question 20

3EL gland Sx.

Answer 20

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.

Question 21

What is the key to resolving a conjunctivitis?

Answer 21

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.

Question 22

What diseases can conjunctivitis be present alongside?

Answer 22

Corneal disease - oedema, keratitis, corneal ulceration.
Intraocular - uveitis, glaucoma.

Question 23

Causes of conjunctivitis.

Answer 23

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.

Question 24

Differential diagnoses for surface ocular disease.

Answer 24

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.

Question 25

Primary conjunctivitis in dogs.

Answer 25

Primary infectious - uncommon.
– viral: CDV, CHV, CAV-2.
– Parasitic: Thelazia spp., Leishmania spp.
Allergic conjunctivitis - concurrent skin disease.
– contact / drug reaction, environmental, atopy, demodex.
Follicular conjunctivitis.
– non-specific to cause, sign of chronicity.
Juvenile conjunctivitis.
– Starts in dogs under 18m, often resolves by adulthood.

Question 26

Approach to conjunctivitis.

Answer 26

Identify cause.
PE.
Thorough ophtho exam.
Check nasolacrimal duct drainage.
Conjunctival swab for cyto and C&S.
Conjunctival ‘snip’ biopsy.
Defect in functional lacrimal unit.

Question 27

Empirical Tx for conjunctivitis.

Answer 27

Topical anti-infectives - treat opportunistic flora until cause resolved.
- Fucidic acid gel BID (L), Chloramphenicol (Off-L) TID-QID.

Topical anti-inflammatories - corticosteroids or NSAIDs.
Immune-mediated cause suspected and ulcers ruled out.

Lubrication, support innate defence of tearfilm. e.g. sodium hyaluronate, carbomer, tear replacement.

Lid hygiene/warm compresses (unless pruritis).

Question 28

Superficial vs deep redness.

Answer 28

Superficial:
- Surface inciting cause.
- Focal to cause.
- Branching, fine vessels.
- Extend from bulbar conjunctiva.
- Do cross limbus.
- Corneal ulcer / other corneal disease.
Deep:
- Deep stromal/intraocular disease.
- Circumferential.
- Fine, short, straight vessels.
- Arise from limbus.
- Do not cross limbus.
- E.g. uveitis, glaucoma, v deep ulcer.

Question 29

Pink proliferative cellular infiltrate clinical signs.

Answer 29

Superficial vessels.
+/- pigments.
pink tissue in acute phase.
White crystalline spots.

Question 30

Chronic superficial keratitis - “Pannus”…
1. Breeds.
2. Effect on patient?
3. Origin/cause?
4. Tx.

Answer 30

1. GSD, Greyhounds.
2. Progressive bilateral, can cause blindness.
3. Immune-mediated.
4. Tx to control, not cure.
   - Topical steroids.
   - Topical cyclosporine (Optimmune).
   - Radiotherapy / superficial keratectomy can be an option.

Question 31

Uveitis.

Answer 31

Breakdown of BAB and BRB.
+/- swelling of iris.
Aqueous flare (protein in aqueous).
Hypopyon (WBC, pus), hyphaema (RBC, clot).
+/- corneal oedema.
+/- low IOP.

Question 32

Bloody eye.

Answer 32

Where is the blood?:
In?
- hyphaema - blood in anterior chamber.
- vitreal haemorrhage.
- retineal haemorrhage.
- mass?
On?
- conjunctiva/cornea/sclera.
- in tear film.
- draining tract?
Around?
- on eyelids, deeper tissues?
- trauma, injury, adjacent structures.

Question 33

Acute glaucoma - a red eye.

Answer 33

Conjunctival hyperaemia.
Episcleral congestion.
Ciliary flush.
Corneal oedema (blue).
Haabs Striae.
Prominent 3EL.
Pain and blindness.
Fixed pupil.