External exam and pupils Flashcards
External examination
GROSS OBSERVATION
General guidelines for external examination
- BE OBSERVANT(watch mobility and speech)
- anything strange?
- pay special attention to Head/ face(head tilt, asymmetry) and ocular adnexa/eyes(differences, lids, grossness)
- ASK PATIENT IN APPROPRIATE WAY AND RECORD IT
Eye lid and ocular adnexa
- Before slit lamp, used naked eye and penlight
- Look for large lesions
- Eyelid position
- palpebral aperture(distance between upper and lower lid-usually 8-11mm.
- Ptosis(drooping)
- retraction(eyes too open)
- exophthalmos(eyes push out)
- enophthalmos(eyes depressed in) - Eyelid movement
- check for forced closure
- make sure eye and upper lid move up when looking up
What the hell should I do if something is weird as shit?
- ask the patient without implying it is abnormal
- ask for onset and duration
- look at old photos
- add testing and history if needed
What is a pupil?
- optics terms-numbers
- physiological- regulates light and neurological processes
- real-not a structure. a hole in the middle of the iris
- controls retinal illumination and retinal image quality
Importance of pupil evaluation
- quick, simple, lots of information
- tells us about neurological problems, ocular problems, systemic problems(drug use/ allergies)
What are the ophthalmic vital signs?
- VA
- pupil check
- pressure
- DR.R includes visual fields
how do we evaluate the pupil?
- shape, position, color of iris
- size
- light reflexes
- swinging flashlight test
- near response
Pupil shape
- normal(round and centered(5 mm))
- correctopia(displacement of the pupil)
Heterochromia
-iris color is different between eyes
Transillumination
- see through iris
- some pigment gets rubbed off
Pupil size
- increases size with SYMPATHETIC ACTIVATION of DILATOR MUSCLE
- decreases size with PARASYMPATHETIC ACTIVATION of SPHINCTER MUSCLE
- sphincter muscle is stronger so para has more control so constriction(miosis) is slightly faster than dilation.
Dilation
- enlargement of pupil via sympathetic activation
- enlargement of pupil via parasympathetic block
- mydriasis
- caused by drugs, hypothyroidism, stimuli
- disturbance and glare are worse with larger diameter
Pupil size testing
- measure in NORMAL LIGHT(if weird, check it in dim)
- make sure it fluctuates constantly(hippus is normal)
- abnormal findings can be bilateral or unilateral
- abnormal findings can be seen in light or dark
NORMAL pupil size
age 20- 5mm in light and 8mm in dark age 80-2mm in light and 2.5 in dark -aging causes a reduction in sympathetic tone -senile miosis -measure by largest diameter -round to nearest 0.5mm
Anisocoria
- significant difference in size of pupils in each eye
- difference of 1mm or more is considered significant
- observe in brightest possible light AND dimmest possible light
- FAIRLY COMMON AND FINE BUT DIAGNOSE TO COVER YOUR BASES
Afferent nerve fibers
- sensory
- eye to brain
- leave each eye at optic nerve and they cross paths at the optic chiasm
Efferent nerve fibers
- motor
- brain to eye
- leave brain and go to EACH EYE
direct and indirect responses to light
- light received in one eye causes constriction in BOTH eyes.
- direct is shine light in left and see constriction in left
- indirect is shine light in left and see constriction in right
Pupillary near reflex
- if light response is normal, you do not need to do it.
- pupil constricts due to accommodation, convergence, and miosis
- is present when direct response is normal, but can be present OR absent in abnormal eye (light-near dissociation)
- can be present in blind eyes
Record pupillary evaluation
- Size(equal)
- Shape(round)
- Light(Reactive
PERRL/PERRLA
Pupils Equal Round Reactive to Light and accomodation
-MG/-APD
- no marcus-gunn pupils
- no afferent pupillary defect
Swinging Flashlight Test
- measures strength of direct response with consensual(indirect) response
- used to assess afferent sensory defects
- shine light 2-4 seconds in right then swing to left for 2-4 seconds 4-5 times
- must be consistent in time between and amount of light exposure in both eyes
Swinging Flashlight test results
- pupils should stay constricted throughout the entire test
- direct/indirect responses should be equal and time between eyes should not allow dilation
Pupillary escape
- APD is present
- pupils will BOTH dilate slightly when afferent eye is illuminated
- binocular dilation is observed when affected eye is direct
- binocular constriction should occur when unaffected eye receives direct light
Ectopic pupil
significantly decentered pupil
Sensor for pupillary light response
- photopic system (cones)
- illumination of the fovea determines light reflex
Pupil cycle
- determined by the rapidity with which the neutral and muscular components act to constrict and dilate the pupil
- quickens with defects
- averaged over 30 cycles
- recorded in milliseconds per cycle(954)
Andie’s tonic pupil
- usually females in 30-40
- unilateral semi-dilated pupil that responds minimally or slow to light
- problem is present in near reflex
- suggest legion on para pathway that affects pupil sphincter
- usually show reduced tendon reflexes in lower extremities
Third cranial nerve palsies
- aniscoria greater in bright conditions
- involves extraocular muscles
- pupillary fibers travel with the third cranial nerve and can be compressed by tumor or legion to result in fixed pupil.
Pharmacological pupil
-neurologically dilated pupils will constrict with 1% pilocarpine, but pharmacological will not
Horner’s Syndrome
- sympathetic innervation to the eye is interrupted
- incomplete dilation in the dark
- miosis, ptosis, anhydrosis
- in congenital cases, can cause heterochromia
Amaurotic Pupil
- occurs in an eye with no light perception
- effected eye does not do by direct, but it does respond indirectly
