Examination of the eye Flashcards
How should examination of the external eye be structured?
ELCSCALVRNOB
external lid can sag causing a lazy vision RNOB
From front-back
- external eye
- lid
- conjunctiva
- sclera/episclera
- cornea
- anterior chamber
- lens
- vitreous
- retina
- nerve
- orbit
- brain
Name six things you would examine an eyelid for
Ptosis, entropion (turning in), ectropion (turning out), masses, edema, erythema
What is the function of the punctae? How might they be examined?
The two lacrimal puncta are in the medial portion of each eyelid and collect the tears produced by the lacrimal glands. They can be examined for patency
What should soft tissue around the eye be examined for?
Swelling, erythema and any skin disorders
How should the skin overlying the nasolacrimal duct be examined?
Palpated for masses
Name six things that would be looked for when examining the conjunctiva
Signs of inflammation, follicles (round collections of lymphocytes), chemosis (swelling), papillae (bumps), unusual pigmentation or hemorrhages
How should the tarsal conjunctiva be visualized?
By everting the lid (lines the eyelids)
What should the sclera be examined for?
Thinning, deep injection of vessels and discoloration (should be white)
How should the cornea appear normally and what should it be checked for and with what tools?
Clear and without cloudiness or opacities, surface can be checked for ulceration or abrasion with fluorescein eye drops and a cobalt blue filter
What should NOT be seen in the anterior chamber? Provide the clinical terms for both abnormalities
Blood - Hyphema
WBCs - Hypopyon
What is the clinical term for inequality in pupillary size and what might it be an indication of?
Anisocoria - may indicate neurological disease (like horner’s or 3rd nerve palsy)
Which drugs can cause mydriasis and miosis?
Miosis/Pupillary constriction: parasympathomimetic/cholinergic drugs
Mydriasis/Pupillary dilation: sympathomimetic drugs or dilating drops
How should the pupils appear normally on examination?
- Equal in size
- Round
- Reactive to light and accommodation (direct and consensual)
- No relative afferent pupillary defect RAPD
What is the iris evaluated for?
Nodules (i.e neurofibromatosis) and abnormal vascularity
If a patient is experiencing diplopia, what details should you specify?
Whether it’s monocular (single eye) or binocular (both eyes)
If the eye is red, what should you ask about?
Discharge, trauma and photophobia
What specific details about someone’s past medical history should you attain during an eye examination?
Previous ophthalmic history (including surgery) and contact lens wear
What four visual functions should you check “around the eye”? Which nerve is responsible for which?
- Visual acuity - optic
- Colour vision - optic
- Field of vision - optic
- Pupil reactions
Describe the field of vision someone would experience if there was a lesion to the R optic nerve directly after the chiasm
Left Homonymous hemianopia
Why?
Left nasal fibres which crossed over in the chiasma are damaged, meaning loss of L temporal vision
R optic temporal fibres (which didn’t cross over) are damaged, meaning loss of R nasal vision
Describe the field of vision someone would experience if there was a lesion to the R optic nerve at its optic radiations
Left Homonymous hemianopia with macular sparing
Why? Lecture
Describe the field of vision someone would experience if there was a lesion to the optic chiasma
Bitemporal hemianopia
Why?
Damage to the L and R nasal fibres means loss of temporal sided vision on both eyes
How would you assess a patient’s field of vision?
- Both eyes open, patient looking at bridge of examiner’s nose - ask if any part appears missing
- Patient covers each eye in turn, examiner keeps opposite eye open and position the target equidistant between examiner and patient
- move from unseen to seen (peripheral - central) - Map out the physiological blind spot
How should a healthy eye react to light exposure and why?
Constriction
What happens in relative afferent pupillary defect RAPD?
The pupils respond differently to light stimuli shone in one eye at a time due to unilateral or asymmetrical retina and/or optic nerve disease
When is RAPD seen maximally?
With the lights low
Describe the pathology of RAPD
Lecture
What is proptosis and how should you examine for it?
Eyes PROtruding (PROptosis) from the orbit, observe patient from above looking down over brow
Name five potential causes for proptosis
- Infection (orbital cellulitis)
- Inflammation (thyroid eye - severe hypothyroidism)
- Tumours
- Vascular abnormalities
- Bony abnormalities
Which optic nerves are responsible for the extraocular eye muscles (one more time)
CN III, IV and VI
How should the setting ideally be when using a direct ophthalmoscope?
Darkened room and dilated pupils
What is the benefit of using the red free (green) filter in a direct ophthalmoscope?
Makes blood and blood vessels black; useful for seeing hemorrhages or new vessels
What is the benefit of using the cobalt blue filter in a direct ophthalmoscope?
Makes fluorescein drops glow green to find corneal epithelial defects
What is a slit beam useful for examining in a direct ophthalmoscope?
Anterior chamber/cornea
What is the range of an intraocular pressure measurement?
10-22
Differentiate between preseptal vs orbital cellulitis
Proptosis
PS - absent
O - present
Ocular motility
PS - normal
O - painful and restricted
Color vision/Visual acuity/RAPD
PS - normal
O - reduced in severe cases
