Introduction and Examinations Flashcards
What questions should you ask someone presenting with subnormal vision?
duration differences between 2 eyes distortion, haloes, floaters of vision flashing lights momentary losses of vision field defects
What questions should you ask someone with visual loss?
monocular/binocular
time of event, method of symptom awareness (covering other eye)
change in symptoms, associated symptoms
visual loss - general/central/associated field/peripheral only/global effect on function
What other questions should you ask someone?
pain/discomfort
discharge
change in lacrimation - increase/decrease
change in appearance - discolouration/swelling/mass/displacement
diplopia
What medical history is significant?
DM HTN COPD Dysthyroid Eye Disease Connective Tissue disease Smoking Hyperlipideamia
Previous ocular history
DH
FH
SH
How do you test visual acuity?
Distance near and far with and without glasses
pin hole test
How do you examine the pupils?
Bright room light exam, dim room light exam
direct and consensual light reflex
swinging flash light test for relative afferent pupillary defect (RAPD)
accommodation reflex
What is proptosis/enophthalmos?
Bulging of the eyes
How do you test visual fields?
confrontation test
How do you test colour vision?
Ishihara colour chart
How do you examine the fundus?
Red reflex
Retina - optic disc, general fundus, macula
What special investigations are used in ophthalmology?
fluorescein angiography
optical coherence tomography
radiological and USS
Haematological/biochemical/bacteriological/immunological diagnosis
What are the main two different types of diagnoses in ophthalmology?
Anatomical - e.g. cataracts
Aetiological - e.g. diabetes
What does a lack of red reflex suggest?
v dense cataracts
vitreous haemorrhage
What does an afferent pupillary defect imply?
an optic nerve problem or a large retinal lesion
What does an efferent pupillary defect imply?
implies a third nerve problem
ie - the efferent limb on the light reflex, with the pupil failing to constrict, but the afferent limb or optic nerve function normal
What does a retinal afferent pupillary defect imply?
defect implies partial optic nerve or significant retinal damage, with some impulses being transmitted
What would be seen in a patient with a complete third nerve palsy?
ptosis - eye would look down and out AND there is is an efferent pupil defect on the affected side
What would be seen in a patient with Horner’s syndrome?
What will the affected pupil look like?
neck scars
partial ptosis
eye may appear sunken in (apparent enophthalmos)
affected pupil is smaller than normal and the anisocaria is more pronounced in the dark
How does Adie’s pupil normally present?
ability of pupil to constrict is impaired so it is larger in one eye
Patient is often young and had efferent pupillary defect on direct and consensual testing with tonic pupil responses. Pupil constriction on convergence is slow but miosis does eventually occur
What does light-near dissociation imply?
implies an abnormal light reflex with a normal near reflex
Why do patients with cortical blindness have normal light responses?
lesions posterior to the optic tract do not affect the light reflex
What is the primary action of medial rectus?
ADDuction
What is the primary action of lateral rectus?
ABDuction
What is the primary action of superior rectus?
Elevation
What is the primary action of inferior rectus?
Depression
What is the primary action of superior oblique?
Intorsion
What is the primary action of inferior oblique?
Extorsion
What is a manifest squint?
- TROPIA
occurs when one or other of the visual axes is not directed towards the fixation point
/
misalingment of the visual axes due to occular muscles imbalance in the binocular state causes a manifest squint or strabismus
(when the eyes are open and being used)
What is a latent squint?
- PHORIA
the deviation of the eyes is only obvious when the binocular single vision is dissociated or inhibited (by performing the alternate cover test)
commonly found in normal population and not normally symptom producing
What is exotropia?
outwards deviation of the affected eye - MANIFEST SQUINT
What is esotropia?
inwards deviation of the affected eye - MANIFEST SQUINT
What is hypertropia?
upwards deviation of the affected eye - MANIFEST SQUINT
What is hypotropia?
downwards deviation of the affected eye - MANIFEST SQUINT
What is cyclotropia?
wheel rotation of the affected eye - MANIFEST SQUINT
What is exophoria?
tendency for eyes to wander outwards on dissociation - LATENT SQUINT
What is esophoria?
tendency for eyes to wander inwards on dissociation - LATENT SQUINT
What is hyperphoria?
tendency for upward deviation - LATENT SQUINT
What is hypophoria?
tendency for downward deviation - LATENT SQUINT
What is cyclophoria?
tendency for wheel rotation - LATENT SQUINT
What are the 3 groups that manifest squints are classified into?
1- primary
2- secondary (to loss or impairment of vision)
3- consecutive (following a squint op)
What are conjugate movements of the eye?
movements of both eyes in the same direction
What are disjugate movements?
movements of the eyes in the opposite direction, termed vergences
What is myopia?
Short-sightness
Light is focused IN FRONT of the retina
Corrected with DIVERGENT lenses
What is hypermetropia?
Long-sightness
Light is focused BEHIND the retina
Corrected with CONVERGENT lenses
What is astigmatism?
a rugby ball shaped eye - changes the way light will be refracted in the eye
symmetrical in all but one direction
Why is ocular movement testing performed?
It is used to identify whether one or more of the extra ocular muscles is under-acting, over-acting or restricted
What are the main advantages of soft contact lenses?
Flexible Good initial comfort Larger diameter incurs secure fit Safer for sports May be used for extended wear
What are the main advantages of rigid gas permeable lenses?
Fixed shape and durable
Good for all day wear
Smaller diameter incurs less risk of hypoxia
Creates smoother ocular surface
Visual result for irregular corneas and high astigmatism
Easy to clean
Good VA if large levels of astigmatism
What are the main disadvantages of soft contact lenses?
Splits easily
Depositions from tear
More expensive
Dehydrates if left out of the solution
What are the main disadvantages of rigid gas permeable lenses?
Poor initial comfort
Smaller diameter therefore prone to fall out the eye
