Ophtho lec 1

What produces and drains tears ate keep the eye moist and shield it from dust and irritants?

What produces and drains tears ate keep the eye moist and shield it from dust and irritants?

lacrimal apparatus

Where are palpebrae/eyelids connected?

medial and lateral canthus

What do the meibomian / tarsal glands do?

modified sebaceous glands that secrete lipid rich product that keeps eyelid from sticking together

What produces aqueous portion of tear film?

lacrimal gland

what produces outer lipid layer to tear film?

meibomian glands

What is the small hole on the medial edge of eyelid that drains tears?

lacrimal punctum

What is the small channel tat drains tears from eye surface into nasal cavity?

lacrimal canaliculus

What is the reservoir for tear overflow and drains eye of debris and microbes?

lacrimal sac

What connects lacrimal canaliculus to lacrimal sac which drain tears into nasal cavity?

nasolacrimal duct

What do the inferior, middle, and superior nasal conchae do?

filter, humidify, and warm are that we breathe to prevent cold air from entering lungs

Where is lacrimal gland?

superolateral corner of orbit

What innervates the lacrimal gland?

greater petrosal nerve (CN VII)

What is the Z axis of eye movement?

horizontal axis in saggital plane with intorsion and extorsion

What is the Y axis of eye movement?

vertical axis in the sagittal place with elevation and depression

What is the X axis of eye movement?

horizontal axis in the axial plane with abduction and adduction

What eye muscles does CN III innervate?

superior rectus, inferior rectus, medial rectus, inferior oblique

What eye muscle does CN VI innervate?

lateral rectus

What eye muscle does CN IV innervate?

superior oblique

Contraction of what muscle dilates the pupil? SNS or PNS? What is it innervated by?

dilator pupillae; sympathetic; CN III

What is the visible colored part of the eye?

iris

What allows light to enter the eye?

pupil

Contraction of what muscle constricts the pupil? PNS or SNS? What innervates it?

sphincter pupillae; PNS; CN III

When does the pupil constrict?

bright light and close vision

When does the pupil dilate?

dim light and distant vision

What muscle closes eye tightly? What innervates it?

orbicularis oculi; CN VII

What muscle elevates superior eyelid? What innervates it?

levator palpebrae superioris; CN III

What CN opens eyes?

CN III

What CN closes eyes?

CN VII

What is bulbar conjunctiva?

covers anterior aspect / sclera of eye, firm attachment to limbus

What is palpebral conjunctiva?

starts at the mucocutaneous junction and lines the eyelids

What is responsible for maintaining shape of globe?

sclera

What is sclera?

white fibrous eye covering that provides strength and flexibility to eye and provides attachment for muscles

What is the cornea?

outermost clear layer of eye; transparent bulging area connected to the sclera that refracts light upon entry

What is the choroid?

vascular, middle layer of the eye

What holds the lens for focusing at different distances?

suspensory ligaments

What do the anterior choroid and ciliary muscle do?

adjust lens diameter for focusing

What divides eye’s anterior cavity?

iris (located between cornea and lens)

What is aqueous humor?

circulates from posterior to anterior chamber of eye and provides nutrients, taste transport, and a fluid cushion

What does aqueous humor pass through before passing to the scleral veins?

canal of schlemm

What are the 3 layers of tear film?

lipid / oily layer, aqueous / watery layer, mucin / mucous layer

What secretes the lipid layer of tear film?

meibomian glands and glands of zeis

What secretes the aqueous layer of tear film?

lacrimal gland and acessories

What secretes the mucin layer of tear film?

goblet cells in conjunctiva

Where is the retina located?

innermost layer, back of eye

What does the retina contain?

rods, cones, macula, fovea

What is the optic disc?

point of entry for CN II that lacks photoreceptors and is insensitive to light; “blind spot”

What is macula lutea?

area behind optic disc that is specialized for high-acuity vision

What is the fovea centralis?

lies within the macula and contains high density photoreceptors where light rays from center of vision land

What is responsible for vision in low light?

rods

What is responsible for visual acuity and color vision?

cones

Where is clear margin and cup, central retinal artery, and veins?

optic nerve

What is the most common cause of reduced visual acuity?

refractive errors

What is presbyopia?

natural loss of accommodation due to age (can’t focus on nearby objects; starts around 40)

what is myopia?

nearsightedness

what is hyperopia?

farsightedness

Does distant vision or near vision need more refraction for focus?

near vision

What is amblyopia?

reduction of vision in one eye due to eye and brain’s inability to work together

What is color blindness?

hereditary x linked disorder characterized by defective/absense of color vision

What is diplopia?

double vision

What is emmetropia?

“normal” refractive condition / clear vision

what is asinometropia?

refractive power of one eye differs from the other

what is strabismus?

misalignment of the eye

What is the most common color blindness?

red-green

Who is color blindness more common in?

men

What do you use to test for color blindness?

ishihara plates

How does color blindness work?

based on perception of red, green, blue;

defect perception of one color results in color being perceives as a combination of the other two

what should be done before instilling any medications? (except for chemical burns)

visual acuity

what must you do to rule out foreign bodies?

flip / evert the lid to examine underneath

what is hypotropia?

downward

what is hypertropia?

upward

what is exotropia?

outward

what is esotropia?

inward

How does cornea and anterior chamber usually appear?

clear w/o crescent shadows

How does optic disc appear normally?

creamy, orange, yellow color with sharp margins

How does optic cup appear normally?

whiter, les than 0.5 cup to disc ratio

How do arteries and veins appear normally?

2:3 ratio without nicking, spasms, copper wire, silver wire, or box car segments

What is helpful in identifying ulcers vs abrasions?

fluorescein stain and woods lamp

What is a slit lamp?

high intensity light source to view front and back of eye

How do you measure interocular pressure? What is it normally?

tonopen; 10-21 mmHg