Ophthalmology SBAs Flashcards
Scenario: A 5-year-old Pug presents with a mucopurulent ocular discharge and marked chemosis in the left eye. The owner reports that the eye has been red and swollen for the past 2 days. Examination reveals the following.
Lead-in: Which of the following is the most likely cause of the ocular discharge?
Options:
a) Keratoconjunctivitis sicca (KCS)
b) Conjunctivitis secondary to entropion
c) Primary bacterial conjunctivitis
d) Feline herpesvirus-1 infection
e) Chlamydophila felis infection
Answer: b) Conjunctivitis secondary to entropion
Explanation: The entropion is causing the eyelashes to rub against the cornea and conjunctiva, leading to irritation and secondary conjunctivitis.
Scenario: A 7-year-old West Highland White Terrier presents with a 1-month history of bilateral mucopurulent ocular discharge. The owner reports that the dog has been squinting and rubbing its eyes. Schirmer tear test readings are 8 mm/min in both eyes.
Lead-in: Which of the following is the most likely diagnosis?
Options:
a) Keratoconjunctivitis sicca (KCS)
b) Conjunctivitis secondary to entropion
c) Primary bacterial conjunctivitis
d) Feline herpesvirus-1 infection
e) Chlamydophila felis infection
Answer: a) Keratoconjunctivitis sicca (KCS)
Scenario: A 4-year-old Labrador Retriever presents with a 1-day history of acute onset blindness. The owner reports that the dog was previously healthy but suddenly became unable to see. On examination, you note that both pupils are dilated and unresponsive to light.
Lead-in: Which of the following is the most likely diagnosis?
Options:
a) Sudden Acquired Retinal Degeneration (SARD)
b) Optic neuritis
c) Retinal detachment
d) Anterior lens luxation
e) Acute glaucoma
Answer: a) Sudden Acquired Retinal Degeneration (SARD)
Explanation: SARD is a condition that causes acute blindness in dogs. The dilated, unresponsive pupils are a key clinical sign.
Scenario: A 9-year-old cat presents with a 1-week history of conjunctivitis and upper respiratory tract signs. You suspect feline herpesvirus-1 infection.
Lead-in: Which of the following is the most appropriate treatment?
Options:
a) Topical corticosteroids
b) Topical fusidic acid
c) Topical ganciclovir
d) Surgical debridement
e) No treatment
Answer: c) Topical ganciclovir
Explanation: Ganciclovir is an antiviral medication that can be used to treat feline herpesvirus-1 infection.
Scenario: A 9-year-old Labrador Retriever presents with a 3-day history of a red, painful right eye. The owner reports that the dog has been squinting and holding the eye closed. You examine the eye and see the following
Lead-in: Which of the following is the most appropriate treatment for this condition?
Options:
a) Topical corticosteroids
b) Systemic antibiotics
c) Topical atropine
d) Topical chloramphenicol
e) Grid keratotomy
Answer: d) Topical chloramphenicol
Explanation: This image shows a superficial stromal ulcer. Topical antibiotics like chloramphenicol are indicated to prevent secondary bacterial infection and promote healing.
Scenario: A 4-year-old Persian cat presents with a history of chronic ocular discharge and corneal opacity in the left eye. On examination, you note the following.
What is the most likely diagnosis?
a) Superficial stromal ulcer.
b) KCS
c) Deep stromal ulcer.
d) Descemetocoele
e) Entropion
c) Deep stromal ulcer.
Scenario: A 12-year-old Miniature Schnauzer presents for a routine health check. On distant direct ophthalmoscopy, you see the following.
The owner reports no concerns regarding vision at home. What is the most appropriate course of action?
Options:
a) Advise the owner that the dog has cataracts and will soon be blind. No treatment is available.
b) Recommend an ERG to assess retinal function prior to cataract surgery.
c) Reassure the owner that the cataracts are not causing any vision problems currently and no action is required at this time.
d) Prescribe topical anti-inflammatory medication to reduce the inflammation caused by the cataracts.
e) Refer the dog to a specialist ophthalmologist for immediate enucleation.
Answer: c) Reassure the owner that the cataracts are not causing any vision problems currently and no action is required at this time.
Explanation: While the dog does have mature cataracts, if vision is not impaired, there is no need for immediate intervention. Cataract surgery is an elective procedure and should only be considered if the cataracts are significantly affecting the dog’s quality of life.
Scenario: A 7-year-old male neutered Border Collie presents with a 2-week history of a red, painful left eye. The owner reports that the dog has been squinting and rubbing its eye. On examination, you note blepharospasm, epiphora, and conjunctival hyperaemia. Fluorescein staining reveals a superficial corneal ulcer. What is the most important next step?
Options:
a) Perform a Schirmer tear test.
b) Perform tonometry.
c) Instil a mydriatic agent.
d) Examine the eye with a slit lamp.
e) Collect a conjunctival swab for bacterial culture and sensitivity.
Answer: a) Perform a Schirmer tear test.
Explanation: It is crucial to identify any underlying cause for the corneal ulcer. Keratoconjunctivitis sicca (KCS), or dry eye, is a common cause of corneal ulceration in dogs. A Schirmer tear test should be performed to assess tear production.
Scenario: A 3-year-old female entire Persian cat presents with a 1-week history of severe corneal ulceration in the right eye. The ulcer is deep and appears to be melting. What is the most important first step in managing this condition?
Options:
a) Perform a grid keratotomy.
b) Prescribe topical corticosteroids.
c) Apply a subpalpebral lavage system.
d) Hospitalize the cat and treat with topical chloramphenicol and serum every 2 hours.
e) Refer the cat to a specialist ophthalmologist for a conjunctival pedicle graft.
Answer: d) Hospitalize the cat and treat with topical chloramphenicol and serum every 2 hours.
Explanation: Melting ulcers are a sight-threatening condition that require intensive medical management. Hospitalization allows for frequent application of topical antibiotics and anti-collagenases, such as serum, to control the infection and prevent corneal perforation.
Scenario: A 1-year-old female entire Shih Tzu presents with a 2-day history of squinting and holding her left eye closed. On examination, you note mucopurulent ocular discharge, conjunctival hyperaemia, and photophobia in the left eye. Fluorescein staining reveals no corneal ulceration. What is the most appropriate treatment?
Options:
a) Topical chloramphenicol
b) Topical fusidic acid
c) Topical dexamethasone
d) Systemic enrofloxacin
e) Lateral canthotomy
Explanation: Fusidic acid is a licensed ophthalmic antibiotic in the UK and is a good first-line choice for treating conjunctivitis. It is effective against Gram-positive organisms, which are the most common cause of conjunctivitis in dogs.
Scenario: A 8-year-old male neutered West Highland White Terrier presents with a 2-month history of a raised, red mass on the conjunctiva of the left eye. The mass is approximately 3 mm in diameter and is located near the limbus. What is the most likely diagnosis?
Options:
a) Conjunctival melanoma
b) Conjunctival mast cell tumour
c) Conjunctival papilloma
d) Conjunctival squamous cell carcinoma
e) Conjunctival haemangioma
Answer: c) Conjunctival papilloma
Explanation: Conjunctival papillomas are benign growths that are relatively common in dogs. They are often small, raised, and red, and can occur near the limbus.
Scenario: A 5-year-old female spayed Labrador Retriever presents with a 1-day history of an acutely painful left eye. The owner reports that the dog was playing in the park when she suddenly yelped and started squinting. On examination, you note blepharospasm, epiphora, and conjunctival hyperaemia in the left eye. Fluorescein staining reveals a deep stromal ulcer. What is the most appropriate treatment?
Options:
a) Topical corticosteroids
b) Topical fusidic acid
c) Topical chloramphenicol and atropine
d) Topical chloramphenicol
e) Surgical debridement and grid keratotomy
Answer: c) Topical chloramphenicol and atropine
Explanation: Deep stromal ulcers require treatment with topical antibiotics to prevent infection and atropine to control reflex uveitis and pain.
Scenario: A 7-year-old male neutered Border Collie presents with a 2-week history of a red, painful left eye. The owner reports that the dog has been squinting and rubbing its eye. On examination, you note blepharospasm, epiphora, and conjunctival hyperaemia. Fluorescein staining reveals a superficial corneal ulcer. You suspect the ulcer is due to keratoconjunctivitis sicca (KCS).
Lead-in: Which of the following diagnostic tests is most likely to confirm your suspicion?
Options:
a) Schirmer tear test
b) Tonometry
c) Slit-lamp biomicroscopy
d) Gonioscopy
e) Electroretinography
Answer: a) Schirmer tear test
Explanation: The Schirmer tear test is a quick and easy test to measure tear production, which is reduced in KCS.
Scenario: A 3-year-old female entire Persian cat presents with a 1-week history of severe corneal ulceration in the right eye. The ulcer is deep, and you see the following (see image of a melting ulcer).
Lead-in: Which of the following is the most appropriate treatment for this condition?
Options:
a) Topical corticosteroids
b) Topical fusidic acid
c) Topical chloramphenicol and serum
d) Surgical debridement and grid keratotomy
e) Topical chloramphenicol
Answer: c) Topical chloramphenicol and serum
Explanation: This image shows a melting ulcer. Melting ulcers require intensive treatment with topical antibiotics, such as chloramphenicol, and anti-collagenases, such as serum.
A 5 year old presents with a painful left eye. After staining, you note the following.
What is the most appropriate treatment?
a) Topical fusidic acid
b) Topical chloramphenicol and serum
c) Diamond burr keratectomy
d) Keratotomy
e) Topical chloramphenicol
Answer: C.
While D is also a correct treatment option, C has a much higher success rate.
You examine a dog which is already receiving medical treatment for
a corneal ulcer. In addition to providing analgesia, how would you
treat this eye?
a) Continue chloramphenicol and add in
ofloxacin and serum every 2 hours
b) Continue chloramphenicol drops 4
times daily
c) Debride with cotton bud, perform grid
keratotomy and place contact lens
d) Enucleation (or referral)
d) Enucleation (or referral)
