Eye Exam Flashcards
Describe hypermetropia/hyperopia
Focuses behind (posterior to) retina because eyeball is too short
Describe myopia
Focuses in front of (anterior to) retina because eyeball is too long
What can cause a light path to be obstructed?
Cataracts
What is the mechanism behind blind spots caused by things like a pituitary tumor?
There is a malfunction somewhere along the visual pathway (from the retina to occipital lobe)
What can spots in the eye be described as?
Retinal debris floating in vitreous humor
What can spots in the eye be caused by?
Retinopathy
What can flashing lights be described as?
Retinopathy, particularly pulling away of retina from choroid, as seen in retinal detachment
Describe double vision
Image focuses on a different area of retina on each eye
What causes ocular malalignment
Weak or abnormally attached extraocular muscles
What can cause a refractive (lens) abnormality?
Cataracts
What can cause double vision?
Ocular malalignment or refractive (lens) abnormalities
What is visual acuity testing a measurement of and what does it test?
Central vision, CN II (optic nerve)
How far away do you position the patient from the Snellen chart when doing visual acuity testing?
20 feet
You record the visual acuity designated by which line when doing this testing?
The smallest line in which the patient can identify all of the letters
How can you reduce the chance of recall influencing visual acuity testing when testing the second eye?
Asking the patient to read the line in the opposite direction
What is OD?
Visual acuity in the right eye
What is OS?
Visual acuity in the left eye
What is OU?
Visual acuity with both eyes open
How else should you measure near vision?
Testing each eye separating using a handheld card like the Rosenbaum Pocket Vision screener, held about 14 in from the eyes
How do you generally estimate peripheral vision?
Confrontation test, though it can be accurately measured with sophisticated instruments
What are some things that could produce confrontation abnormalities when testing peripheral vision?
Stroke, retinal detachment, optic neuropathy, pituitary tumor compression at the optic chiasm, and central retinal vascular occulsion
What is red testing particularly helpful in determining?
Subtle optic nerve disease, even when visual acuity remains nearly normal
What does an afferent pupillary defect often coexist with?
A red defect
How would you carry out an examination of the external structures of the eye?
Start with the appendages (like the eyebrows and surrounding tissues) and moving inward
A patient with hypothyroidism may have which features in regards to their eyebrows?
Coarse eyebrows that don’t extend beyond the temporal canthus
What may periorbital edema may be indicative of?
Thyroid eye disease, allergies, or (especially in youth), the presence of renal disease (nephrotic syndrome)
What is xanthelasma?
An elevated plaque of cholesterol deposited in macrophages, most commonly in the nasal portion of the upper or lower lid, observed as flat to slightly raised oval, irregularly shaped, yellow tinted lesions on the periorbital tissues
The presence of fasciculations or tremors of the eyelids when lightly closed may be a sign of what?
Hyperthyroidism
When would you say ptosis is present?
If one superior eyelid covers more of the iris than the other or extends over the pupil
Where is the average lower lid position?
At the lower limbus
Describe lagophthalmos and what it causes an increased risk of.
Lagophthalmos is when the closed lids do not completely cover the globe, so the cornea may become dried, increasing risk of infection.
What are some common causes of lagophthalmos?
Thyroid eye disease, seventh nerve palsy (Bell palsy), and overaggressive ptosis or blepharoplasty surgical repair
What is ectropion?
When the lower eyelid is turned away from the eye. It may result in excessive tearing.
What is entropion?
When the lower eyelid is turned inward toward the globe. The lid’s eyelashes may cause corneal and conjunctival irritation, increasing risk of a secondary infection
A hordeolum or stye is generally caused by what?
A staphylococcal infection
An internal hordeolum involves what?
Meibomian glands
Describe normal conjunctivae
Translucent and free of erythema
An erythematous or cobblestone appearance, especially on the tarsal conjunctiva, may indicate what?
An allergic or infectious conjunctivitis
What would indicate a subconjunctival hemorrhage?
Bright red blood in a sharply defined area surrounded by healthy-appearing conjunctiva
What is a pterygium?
An abnormal growth of conjunctiva that extends over the cornea from the limbus
A pterygium is more common in what type of people?
Those heavily exposed to ultraviolet light
Arcus senilis in a person under 40 may indicate what?
A lipid disorder
What is arcus senilis?
A deposit of lipids in the periphery of the cornea, seen in many individuals older than 60n
Decreased corneal sensation is often associated with?
Diabetes, herpes simplex and herpes zoster viral infection, and after trigeminal neuralgia surgery
How would you examine the “flatness” of the anterior chamber?
By shining a light tangentially on it
What is corneal sensitivity controlled by and how is it tested?
By CN V, tested by touching a wisp of cotton to the cornea
If liver or a hemolytic disease is present, what would you expect to see when examining the sclera?
Pigmented sclera that appears either yellow or green
What does senile hyaline plaque appear as?
A dark, slate gray pigment just anterior to the insertion of medial rectus muscle
When would you expect to see enlarged lacrimal glands?
Enlarged lacrimal glands are rare, but can be seen in conditions like Sjogren syndrome, and patients may report dry eyes because the glands produce inadequate tears
When examining the pupils, what is expected?
The pupils should be round, regular, and equal in size, and any irregularity should be noted
The pupils response to light should be tested how?
Both directly and consensually
What are some contributing factors for miosis?
Iridocyclitis, miotic eye drops (like pilocarpine), and drug abuse
What are some contributing factors for mydriasis?
Mydriatic or cycloplegic drops (like atropine), midbrain lesions or hypoxia, drug abuse
Describe Argyll Robertson pupil
Bilateral, miotic, irregularly shaped pupils that fail to constrict with light but retain constriction with conversion, and may or may not be equal in size
What is a common cause of Argyll Robertson pupil?
Neurosyphilis
Acute uveitis is commonly what?
Unilateral
What are signs of oculomotor nerve damage?
Pupil dilated and fixed, eye deviated laterally and downward, ptosis
What would you expect to see in an Adie pupil?
Affected pupil is dilated and reacts slowly or fails to react to light, but responds to convergence, and is often accompanied by diminished tendon reflexes
What is Adie pupil commonly caused by?
Impairment of postganglionic parasympathetic innervation to sphincter pupillae muscle or ciliary malfunction
What are common causes of anisocoria?
It can be congenital or caused by local eye medications, or unilateral sympathetic or parasympathetic pupillary pathway destruction
Full movement of the eyes is controlled by what?
The integrated function of CNs III, IV, and VI and the six extraocular muscles
What is sustained nystagmus?
Involuntary rhythmic movement of the eyes that can occur in a horizontal, vertical, rotary, or mixed pattern
Describe jerking nystagmus
Characterized by faster movements in one direction and defined by its rapid movement phase
What is lid lag?
The exposure of the sclera above the iris when the patient is asked to follow your finger as you direct the eye in a smooth movement from ceiling to floor
Lid lag may indicate what?
Thyroid eye disease (Grave’s disease)
What are some types of ocular malalignments?
Heterotropia and heterophoria
What is heterotropia?
Strabismus/Squint - a manifest lack of parallelism of the visual axes of the eyes
What is esotropia?
A type of heterotropia where the affected eye turns in, toward the nose
What is exotropia?
A type of heterotropia where the affected eye turns out, toward the temple
What is hypertropia?
A type of heterotropia where the affected eye turns up, toward the forehead
What is hypotropia?
A type of heterotropia where the affected eye turns down, toward the chin
What is heterphoria?
An occult lack of parallelism of the visual axes of the eyes, prevented by binocular vision
What is the corneal light reflex used for?
To test the subtle balance of the extraocular muscles
What does inspection of the interior of the eye permit?
Visualization of the optic disc, arteries, veins, and retina
How would you examine a patient’s right eye using an ophthalmoscope?
Examine a patient’s right eye with your right eye and their left eye with your left while holding the ophthalmoscope in the hand that corresponds to the examining eye
If your patient is myopic, what type of lens will you need to use in the ophthalmoscope?
A minus (red) lens
If your patient is hyperopic, what type of lens will you need to use in the ophthalmoscope?
A plus lens
Why is the optic disc considered a blind spot?
It is where the retina converges to the optic nerve and there are no photoreceptors in this part of the eye, so it can’t respond to light stimulation
How do the blood vessels of the optic disc divide?
Into superior and inferior branches, then into nasal and temporal branches
When examining the optic disc, what should you expect?
The disc margin should be shark and well defined, especially in the temporal region, and it is generally yellow to creamy pink, depending on race
What is the macula and where can you find it?
The macula, or fovea centralis, is the site of central vision and is located approximately 2 disc diameters temporal to the optic disc
Will you always be able to see the macula when examining a non-dilated eye?
No, it may be impossible to examine when the pupil isn’t dilated because shining a light on it induces strong pupillary constriction
What would you ask a patient to do in order to bring the macula into your field of vision?
To look directly at the light of the ophthalmoscope
How should the macula appear upon examination?
As a lighter dot surrounded by an avascular area, as no blood vessels enter it
What would you expect to see with papilledema?
Loss of definition of an optic disc margin
How would you distinguish myelinated retinal fibers from chorioretinitis?
An absence of pigment, feathery margins, and full visual fields help distinguish this benign condition from chorioretinitis
What are some general signs of retinopathy?
Reduced visual acuity, visual field defect, white and/or red spots in the retinal exam, and disturbances of blood vessels
What kind of spots might you seen in a retinal exam that are indicative of retinopathy?
White spots, including cotton wool spots, hard exudates, and drusen, or Red spots, including hemorrhages and microaneurysms
Describe flame-shaped hemorrhages
Occur in the nerve fiber layers and the blood spreads parallel to the nerve fiber, and typically appears bright red
Describe round hemorrhages
Tend to occur in deeper layers and may appear as a dark red color
What types of disturbances of blood vessels are considered general signs of retinopathy?
Increased light reflex, generalized narrowing, crossing changes, arteriolar straightening, tortuosity, neovascularization
