Opthalmology - History and Examination

Question 1

Patient presents with red eye

List key questions and d/dx

Answer 1

Question 2

Patient presents with acute vision loss

List key questions and d/dx

Answer 2

Question 3

Patient presents with chronic visual loss

List key questions and d/dx

Answer 3

Question 4

Patient presents with ocular pain

List key questions and d/dx

Answer 4

Question 5

Patient presents with diplopia

List key questions and d/dx

Answer 5

Question 6

Patient presents with ptosis

List key questions and d/dx

Answer 6

Question 7

Outline opthalmic history framework and core questions

Answer 7

History of present illness (HPI):
Chief complaint:
→ Onset: acute (eg. vascular), subacute (eg. optic neuritis), chronic, acute on chronic (eg. acute glaucoma attack)
→ Laterality: Rt (OD), Lt (OS), both (OU)
→ Quality
→ Severity
→ Progression: intermittent vs constant, progressive vs stable
→ Aggravating and relieving factors □ Associating symptoms: ocular and non-ocular symptoms

Past ocular history (POH):
□ Hx of eye disease, incl refractory error
□ Hx of ocular surgery
□ Hx of eye trauma
□ Hx of contact lens wearing

Past medical history (PMH):
□ Vascular diseases, eg. HTN, DM, coronary or cerebrovascular disease
□ Systemic inflammatory diseases, eg. sarcoidosis, CTD, Behcet’s disease
□ Allergic diseases, eg. allergic rhinitis

Drug Hx
□ Current and past medications
□ Drug allergies

Social history:
□ Smoking and alcohol when relevant, eg. vascular event, unexplained optic neuropathy
□ ADL

Family history, eg. retinitis pigmentosa (inherited), glaucoma (FHx is a RF)

Question 8

Red flag opthalmological symptoms

Answer 8

 Red eye (redness ± pain, photophobia, discharge) → usually indicates anterior ocular pathology

 Painless loss of vision → usually posterior pathology

 Glare → usually indicates cataract

 Distortion (metamorphosia), central scotoma → usually macular pathology

 Flashes (photopsia) and floaters → usually vitreoretinal pathology

Question 9

Outline basic and additional clinical exams of the eye

Answer 9

Basic examination:
□ External appearance: eyebrows, eyelids, lacrimal apparatus, obvious ocular abnormalities (eg. squint)
□ Visual acuity (VA): distance vs near acuity, aided vs unaided, ± pinhole
□ Visual field (VF): confrontation or mid-peripheral vision, Goldman perimeter
□ Pupils: symmetry, direct and consensual response, accommodation reflex, swinging torch test
□ Ocular movement and alignment: EOM test, Hirschberg test, cover and uncover test

**Additional examination: **
□ Fluoroscein staining for corneal abrasion and injury
□ Slit lamp (biomicroscopy) for anterior segment examination
□ Goldmann tonometer for intraocular pressure measurement
□ Fundoscopy: disc, retinal vasculature, macula, peripheral retina

Question 10

External exam of the eye

Features to look for

Answer 10

Eyebrows: asymmetry, scarring

Eyelids:
□ Lumps, eg. stye, chalazion, xanthelasma
□ Swelling, eg. blepharitis
□ Abnormalities in position
→ Ptosis: measure distance between upper and lower lids and excursion of upper lid from extreme downgaze to extreme upgaze
→ Entropion and ectropion: eyelid turning inward and outward respectively
□ Eyelash problems, eg. trichiasis (lashes arise from normal position but are posteriorly directed)

Lacrimal apparatus:
□ Tear film: epiphora (watery eye), dry eye
□ Lacrimal swelling: dacryocystitis (lacrimal sac infection)

Question 11

Visual acuity testing:

• Types
• Interpretation
• Charts used

Answer 11

Types:
□ Unaided vs aided: w/o and w/ spectacles respectively
□ Best corrected VA (BCVA): tested w/ trial lenses (gold standard)
□ Near vs distance: test VA at distance (usu 6m) or near (usu ~30cm)

VA expressed as d/D:
□ d = distance at which pt is reading chart
□ D = distance at which pt is expected to be able to read chart

Interpretation:
□ Normal = 6/6 (20/20)
□ <6/9 (20/30) → use pinhole occluder to correct refractory error
□ <6/120 (20/400) → try to determine if pt can → Count fingers (CF) → Hand movement (HM) → Light perception (LP) → No perception of light (NLP)

Charts:
□ Snellen’s chart
□ LogMAR charts, eg. ETDRS chart
→ MAR = min angle of resolution
≈ 1/Snellen’s quotient (eg. 6/60 = 10)
□ Other variants, eg. Landolt C, illiterate E test

Question 12

Visual field testing

• Steps
• Types

Answer 12

Confrontation:
→ Pt at one arm length, fixate on your pupil
→ One eye covered, no spectacles
→ Object midway between you and pt
→ Ask patient to focus on your eye
Coloured pin/moving finger brought into visual field from four quadrants (superotemporal, superonasal, inferotemporal, inferonasal)
→ ask pt to tell you when object is seen
→ compare your own VF vs patient’s VF

Types:
- Clincal VF confrontation test
Formal tests:
- Goldmann perimetry: manual VF recording using suprathreshold stimuli → detects relative scotomas only
- Humphrey’s perimetry: digital VF recording using threshold stimuli → detects absolute scotomas

Question 13

Outline pupil exam

Answer 13

Size and symmetry:
□ Anisocoria = asymmetry of pupillary size
□ In PN disease, pathological pupil is the larger one (mydriatic)
□ In SN disease, pathological pupil is the smaller one (miotic)

Pupillary light reflexes:
Direct response testing ipsi afferent + ipsi efferent functions
Consensual response testing contra afferent + ipsi efferent functions

Near reflex: to test afferent + efferent function via accommodation, convergence, miosis

Swinging torchlight test for relative pupillary afferent defect (RAPD): compare afferent pathways for optic nerve lesions

Question 14

Ddx light-near dissociation

Answer 14

Light-near dissociation: pupils react to near reflex but not to light

→ Argyll-Robertson pupils: classically a/w midbrain lesions due to neurosyphilis or DM

→ Adie’s tonic pupil: ciliary ganglionitis leading to denervation of pupillary sphincter and pupillary reinnervation by accommodation fibres originally to ciliary body

→ Parinaud syndrome: dorsal midbrain lesion due to eg. MS

Question 15

Eye movement exams

Answer 15

Hirschberg (corneal light reflex) test for any squints (strabismus)
- Torch light held directly ahead (33cm away) with eye in primary position (forward gaze)
- Normal = reflection of light from cornea should be symmetrical
- Squint = reflection from non-fixating eye is displaced
- Pseudosquint = reflection at same position but appear to have squint because of eyelid asymmetry

ROM: abnormal features:
- Diplopia (more sensitive) or malalignment
- Limitation of range (ophthalmoplegia)
- Nystagmus

Cover/uncover test for non-paralytic squints:
Manifest squint (heterotropia) seen in primary gaze
- Affects one eye only with the other used as fixation
Latent squint (heterophoria) NOT seen in primary gaze
- Only seen when binocular fusion is interrupted
- Refers to tendency of visual pathways to drift apart but usually corrected by unconscious effort, i.e. reflects a disparity rather than affect a specific eye

Question 16

Diagnostic uses of fluorescein stain

Answer 16

Principle: fluorescein absorbs blue light and emits green fluorescence

Uses: -
Examination of corneal abrasion/ulcers → any corneal abrasion fluoresces bright green

Examination of corneal breaks leading to aqueous leaks → bright green at junction w/ dark concentrated fluorescein

Question 17

Diagnostic uses of slit lamp exam

Answer 17

Principle:
→ Biomicrosope for magnified stereoscopic view
→ Slit of light directed to highlight a cross-section of transparent media of eye to be examined

Uses: examination of lids and anterior segment
□ Conjunctiva: any injection and distribution? Any discharge? Any subconjunctival haemorrhage?
□ Cornea: clarity? Any opacity or defects? Any oedema?
□ Anterior chamber: Is it intact? Any hypopyon or hyphaema? Any keratic precipitates? Any cells and flare?
□ Iris/pupils: Is shape of pupil normal?
□ Lens: Any opacities/clouding?

Question 18

Intra-ocular pressure tests?

Answer 18

Goldmann tonometer
Non-contact devices using puffs of air
Hand-held US pachymeters to measure corneal thickness to correct IOP measurements

Question 19

Fundoscopic exam

• Types
• Steps
• Adjustments

Answer 19

Types: direct ophthalmoscopy, indirect ophthalmoscopy, special lenses in slit lamp

Steps:
1. Lights dimmed, pt looks straight ahead at distance
2. Patient’s pupil first dilated with 1% tropicamide (cycloplegic), 2.5% phenylephrine (mydriatic) or Mydrin-P (combination eyedrop)
3. Examiner’s Rt eye used to examine pt’s Rt eye etc
4. First view the red reflex through pupil at a distance of about ~30cm from eye, further visualized by turning the ophthalmoscope to the hypermetropic side
5. Follow the red reflex and approach the eye to within a few cm → re-focus by adjusting to myopic side
6. Examine the optic disc, retinal vasculature, macula and retina

Adjustments:
- Lenses to adjust magnification power
- Rheostat to adjust brightness of light source
- Apertures: usually use large aperture
- Filters: slit, red-free filter for pale disc/ small vessles, grid

Question 20

Fundoscopic exam
- Features to look for

Answer 20

Optic disc: approach at 15o temporal to gaze line
- Colour: pale in optic atrophy (temporal pallor in MS)
- Contour: blurred margins in papilloedema OR papillitis
- Cup-to-disc ratio: increased (>0.4) in glaucoma
- Disc vessels: neovascularization in proliferative DMR

Retinal vasculature:
- Arteries: bright red, thinner, reflects light (due to sm content)
- Veins: darker red, larger caliber
- HTN retinopathy: AV nipping, silver/copper wiring

Macula: central part of retina bound by sup. and inf. retinal vv.
- Foveal reflex: in youth, foveal pit appears at bright pinpoint of light in centre of retina
- Abnormal lesions, eg. haemorrhage, exudates, CWSs

Retina: systematically in a 360o sweep
- Look for exudates, haemorrhages, colour changes and other lesions

Question 21

Types of retina exudates

Answer 21

Exudates:
Soft exudate (cotton wool spots, CWS) with blurred margins
- Due to microinfarcts of axons
- Seen in microangiopathic ds, eg. DM, HTN

Hard exudate with well-defined margins
- Due to lipoprotein leakage from vessels
- Seen in ↑capillary permeability, eg. DMR

Question 22

Types of retinal hemorrhages

Answer 22

→ Flame-shaped haemorrhage:
- Due to blood accumulating at nerve fibre layer
- Seen in ↑capillary pressure, eg. HTN, RVO, papilloedema, bleeding disorder
→ Dot-and-blot haemorrhage (microaneurysms):
- Due to impaired vascular autoregulation ± rupture
- Specific for diabetic retinopathy
→ Subhyaloid haemorrhage:
- Due to blood between vitreous and retina
- Specific for subarachnoid haemorrhage
→ Vitreous haemorrhage:
- Due to bleeding into vitreous humour

Question 22

Types of retinal vascular obstruction

Answer 22

→ Central retinal artery obstruction (CRAO):
- Pan-retinal pallor with cherry red spot at fovea
- Due to ↓perfusion of retina with macular sparing (derives blood supply from choroid)

→ Branch of retinal artery obstruction (BRAO):
- Partial retinal pallor with partial cherry red spot

→ Central retina vein obstruction (CRVO):
- ‘Blood and thunder’ appearance with disc swelling, diffuse flame haemorrhage and CWSs

Question 23

Causes of the following retinal lesions

Answer 23

→ Laser photocoagulation scars for DM retinopathy

→ Retinal detachment with elevated sheet of retinal tissues with fold - Look for corresponding VF defect (opposite to site of lesion)

→ Retinitis pigmentosa: dark deposits of irregular clumps of pigments

Question 24

Causes of disc pallor and blurred optic disc margin

Answer 24

Disc pallor in optic atrophy

Blurred disc margin in
- Papilloedema: bilateral, a/w diffuse flame-shaped haemorrhage, visual loss if any usually only transient, S/S of ↑ICP
- Papillitis: may be unilateral, no flame-shaped haemorrhage, visual loss more prominent due to optic neuritis

Question 26

Feratures of diabetic retinopathy

Answer 26

• Retinal microangiopathy → microaneurysm, dot-and-blot haemorrhage
• Retinal ischaemia → cotton wool spots, venous beading, intra-retinal microvascular abnormalities (IRMA)
• Breakdown of blood-retinal barrier → hard exudates, macular oedema
• Vasoproliferation → neovascularization → vitreous haemorrhage, tractional retinal detachment, rubeosis iridis ± acute rubeotic glaucoma

Question 27

Grades of hypertensive retinopathy

Answer 27

Hypertensive retinopathy:
- Grade I = silver wiring
- Grade II = G1 + arteriovenous nipping
- Grade III = G2 + flame-shaped haemorrhage and CWS
- Grade IV = G3 + papilloedema