DHA Optometrist exam questions

6 worked Optometrist practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Anterior Segment Disease

   A contact lens wearer who rinses her lens case with tap water has severe eye pain for 3 weeks, out of proportion to mild signs. There is a patchy epithelial keratitis and radial infiltrates along corneal nerves. What is the most likely diagnosis?

   1. AAcanthamoeba keratitis
   2. BHerpes simplex dendritic keratitis
   3. CMarginal keratitis from blepharitis
   4. DAdenoviral keratoconjunctivitis
   Show answer and explanation

   Correct answer: A. Acanthamoeba keratitis

   Acanthamoeba keratitis is linked to exposure of lenses to water and typically causes severe pain with early epithelial changes and radial perineuritis, later forming a ring infiltrate. It is often misdiagnosed as herpes. Urgent referral for specialist diagnosis and anti-amoebic treatment is required.

   Reference: Kanski's Clinical Ophthalmology, 9th ed.

2. Question 2 · Binocular Vision and Orthoptics

   During a cover test for distance, when the left eye is covered, the right eye moves outward to take up fixation. What does this indicate?

   1. ARight exotropia
   2. BRight esotropia
   3. CLeft hypertropia
   4. DEsophoria only
   Show answer and explanation

   Correct answer: B. Right esotropia

   A movement of the uncovered eye to take up fixation shows a manifest deviation. An eye that moves outward was previously turned in, so this is a right esotropia. A phoria is shown by the alternate or cover-uncover test, with the covered eye moving on uncovering.

   Reference: Rowe, Clinical Orthoptics, 3rd ed.

3. Question 3 · Glaucoma

   A 68-year-old hyperopic woman has a painful red right eye with headache, nausea and haloes around lights. The cornea is hazy and the pupil is mid-dilated and unreactive. What is the most likely diagnosis?

   1. AAcute anterior uveitis
   2. BAcute primary angle closure
   3. CBacterial conjunctivitis
   4. DEpiscleritis
   Show answer and explanation

   Correct answer: B. Acute primary angle closure

   Pain, nausea, haloes, a hazy cornea and a fixed mid-dilated pupil are classic features of acute angle closure, which raises IOP sharply and needs emergency referral. Uveitis usually gives a small pupil. Conjunctivitis and episcleritis do not affect the pupil or cause haloes.

   Reference: European Glaucoma Society Terminology and Guidelines for Glaucoma, 5th ed.

4. Question 4 · Posterior Segment and Neuro-ophthalmology

   A patient with type 2 diabetes is examined with dilated fundoscopy. Which finding alone meets the 4-2-1 rule for severe non-proliferative diabetic retinopathy?

   1. AHard exudates within 1 disc diameter of the fovea
   2. BVenous beading in 2 or more quadrants
   3. CMicroaneurysms in each of the 4 quadrants
   4. DCotton wool spots in 1 quadrant
   Show answer and explanation

   Correct answer: B. Venous beading in 2 or more quadrants

   Severe NPDR is defined by any one of: severe intraretinal haemorrhages in all 4 quadrants, venous beading in 2 or more quadrants, or intraretinal microvascular abnormalities in 1 or more quadrant. Microaneurysms alone are not severe haemorrhages. Exudates near the fovea indicate maculopathy, a separate assessment.

   Reference: ETDRS Research Group; International Clinical Diabetic Retinopathy Disease Severity Scale, Ophthalmology 2003

5. Question 5 · Posterior Segment and Neuro-ophthalmology

   On the swinging flashlight test, the left pupil dilates when the light moves from the right to the left eye. Both media are clear and the left fundus looks normal. Where is the lesion most likely to be?

   1. ALeft optic nerve
   2. BLeft lens nucleus
   3. CRight optic tract only
   4. DLeft oculomotor nerve
   Show answer and explanation

   Correct answer: A. Left optic nerve

   A left relative afferent pupillary defect with clear media and a normal fundus points to a left optic nerve lesion such as retrobulbar optic neuritis. Cataract does not cause a significant RAPD. An oculomotor lesion affects pupil constriction itself, an efferent problem, rather than causing an RAPD.

   Reference: Kanski's Clinical Ophthalmology, 9th ed.

6. Question 6 · Refraction and Clinical Optics

   A patient wears spectacles of -10.00 DS at a back vertex distance of 12 mm and wants contact lenses. What is the nearest contact lens power?

   1. A-8.00 DS
   2. B-9.00 DS
   3. C-10.00 DS
   4. D-11.25 DS
   Show answer and explanation

   Correct answer: B. -9.00 DS

   Effective power at the cornea is F / (1 - dF) = -10 / (1 - 0.012 x -10) = -10 / 1.12, which is about -8.93 D, so -9.00 DS is nearest. Minus lenses moved closer to the eye need less power. Vertex distance becomes clinically important above about 4 D.

   Reference: Tunnacliffe, Introduction to Visual Optics, 4th ed.