Eyes and Vision Problems Flashcards
bony structure 4cm, 4 sided pyramid,
surrounded by sinuses
Orbit
Sinuses that surround the orbit
Ethmoid (medially)
Frontal (superiorly)
Maxillary (inferiorly)
protect the anterior portion of the
eye, multiple glands, including sebaceous,
sweat, and accessory lacrimal glands;
innervated by the oculomotor nerve (CN III).
Eyelids
CN III- controls the eyelids
oculomotor nerve
3 Layers of tears
Lipoid, aqueous, and mucoid
lacrimal gland and the accessory
lacrimal glands;
Tears
it comprises of 4 rectus muscles and 2 oblique
Extraocular muscles
CN that innervated extraocular muscles
cranial nerves (CN) III, IV, and
VI.
barrier and nourishes the eye
Conjunctiva
Produce and secrete lubricating mucus
Goblet cells
conjunctiva in sclera
Blulbar conjunctiva
conjunctiva in eyelids
Pelpebral conjunctiva
junction in conjunctiva
Fornix
conjunctiva meets cornea
Limbus
white of the eye, maintains shape
Sclera
color of the sclera in children
bluish tinge
color of the sclera in elderly
yellowish
main refracting surface of the eye; 5 Layers
Cornea
behind cornea,filled with continually replenished supply of clear aqueous humor, which nourishes the cornea
Anterior chamber
produced by the ciliary body, related to the intraocular pressure
Aqueous humor
normal IOP
10-21 mmHg
Consists of Iris, Ciliary Body, Choroid
Iris
Uvea
Colored part of the eye, highly
vascularized, pigmented collection of
fibers surrounding the pupil.
Iris
dilates and constricts in response to light, round and constrict symmetrically when a bright light shines on them,
Pupil
% of the population have pupils that are slightly unequal in size but that respond equally to light
20%
parasympathetic NS (pupil)
Sphincter pupillae
sympathetic NS (pupil)
Dilator pupllae
biconvex structure held in position by zonular fibers, behind pupil and iris.
lens
enables focusing for near vision and
refocusing for distance vision.
lens
ability to focus and refocus.
Accommodation
controls accommodation through the zonular fibers and the ciliary muscles
Ciliary Body
a small space between the vitreous and
the iris;
posterior chamber
aqueous fluid flows from the posterior chamber into the anterior chamber, from which it drains through the trabecular meshwork into the
canal of Schlemm
lies between the retina and the sclera. It is avascular tissue, supplying blood to the portion of the sensory retina closest to it.
Choroid
largest chamber of the eye and contains the vitreous humor
Ocular fundus
clear, gelatinous substance, composed mostly of water and encapsulated by a hyaloid membrane
Vitreous humor
occupies about two thirds of the eye’s volume and helps maintain the shape of the eye; shrinks and shifts with age
Vitreous humor
perceived due to gradual loss of gel-like characteristics.
Floaters fiber shadows of various cells
and fibers
innermost surface of the fundus, 10 microscopic layers, consistency of a wet tissue paper, neural tissue
Retina
pink; it is oval or circular and has sharp margins; point of entrance of the optic nerve into the retina
optic disc
area of the retina responsible for central vision
Macula
area of the retina responsible for peripheral vision
Retina
center of macula, most sensitive area; avascular and surrounded by the superior and inferior vascular arcades.
Fovea
2 Important Layers of Retina
Retinal Pigment Epithelium (RPE)
Sensory Retina
Layer of retina: absorption of light
Retinal Pigment Epithelium (RPE)
Layer of retina: contain photoreceptor cells
sensory retina
photoreceptor cells
Rods and Cones
night vision/low light/absent in fovea
Rods
bright light/color vision
Cones
is also known as the second cranial nerve (CN II), transmits impulses from the retina to the occipital lobe of the brain
Optic Nerve
leaves the eye and then meets the optic nerve from the other eye at the optic chiasm.
Optic Nerve
The anatomic point at which the nasal fibers from the nasal retina of each eye cross to the opposite side of the brain
Chiasm
healthy functioning of the: eyeball, intact visual
pathway
Visual Acuity
the colored parts of the eyes, called the irises, usually don’t have enough pigment. This allows light to shine through the irises and makes the eyes extremely sensitive to bright light.
Albinism
eye disorder characterized by a complete or partial absence of the colored part of the eye
Aniridia
group of eye diseases that can cause vision loss and blindness by damaging a nerve in the back of your eye called the optic nerve; comprehensive dilated eye exam
Glaucoma
autosomal recessive inborn error of amino acid metabolism that results in inability to break down homocysteine to cystathionine due to deficiency in the enzyme cystathionine beta-synthase.
Homocystinuria
is toxic to cells, so its accumulation can lead to abnormalities in the eye, skeletal system,
vascular system, and central nervous system.
Homocysteine
discoloration or displacement of the lens. Lens is defined as luxated (dislocated) when it lies completely outside of the hyaloid fossa, is free-floating in the vitreous, is in the anterior chamber, or lies directly on the
retina.
Ectopia lentis
Common clinical manifestation of having homocysteine
Ectopia lentis
measure of the ability of the eye to distinguish shapes and the details of objects at a given distance
Visual acuity
Visual Acuity abv in left eye
OS
Visual Acuity abv in right eye
OD
composed of a series of progressively smaller rows of letters, is used to test distance vision.
Snellen chart
considered the standard of normal vision.
20/20
If the patient cannot count fingers, the examiner raises one hand up and down or moves it side to side and asks in which direction the hand is moving. This level of vision is known as
hand motion (HM)
A patient who can perceive only light is described as having
Light perception (LP)
The vision of a patient who cannot perceive light is described as
no light perception (NLP)
is a hand-held instrument with various plus and minus lenses. The lenses can be rotated into place, enabling the examiner to bring the cornea, lens, and retina into focus sequentially
Direct Opthalmoscope
an instrument commonly used by the ophthalmologist to see larger areas of the retina, although in an unmagnified state. It produces a bright and intense light.
Indirect Opthalmoscope
a binocular microscope mounted on a table. This instrument enables the user to examine
the eye with magnification of 10 to 40 times the real image. The illumination can be varied from a broad to a narrow beam of light for different parts of the eye.
Slit lamp
The most common color vision test is performed by using
Ishihara polychromatic plates.
These plates are bound together in a booklet. On each plate of this booklet are dots of primary colors that are integrated into a background of secondary colors. The dots are arranged in simple patterns, such as numbers or geometric shapes
Ishihara polychromatic plates
Vision is impaired because a shortened or elongated eyeball prevents light rays from focusing sharply on the retina.
Refractive errors
consists of placing various types of lenses in front of the patient’s eyes to determine which lens best improves the patient’s vision
Ophthalmic refraction
normal vision
Emmetropia
(nearsightedness) | Deep eyeballs | Image front of retina
Myopia
(farsightedness) | Shallow eyeballs | Image beyond retina
Hyperopia
is the gradual loss of your eyes’ ability to focus on nearby objects; part of aging
Presbyopia
an irregularity in the curve of the cornea
Astigmatism
is a general term describing visual impairment
hat requires patients to use devices and strategies in addition to corrective lenses to perform visual tasks
Low vision
Low vision is defined as a best corrected visual acuity (BCVA) of
20/70 to 20/200
defined as a BCVA that can range from 20/400 to no light perception.
Blindness
The clinical definition of absolute blindness is the
absence of light perception.
is a condition of impaired vision in which a person has a BCVA that does not
exceed 20/200 in the better eye or whose widest visual field diameter is 20 degrees or less.
Legal blindness
a is a group of eye diseases that can cause vision loss and blindness by damaging a nerve in the back of your eye called the optic nerve
Glaucoma
direct mechanical theory in glaucoma
suggests that high IOP damages the retinal layer as it passes through the optic nerve head
Indirect ischemic theory
suggests that high IOP compresses the microcirculation in the optic nerve head, resulting in cell injury and death
silent thief of sight”, blurred vision or “halos” around lights, difficulty focusing, difficulty adjusting eyes in low lighting, loss of peripheral vision, aching or discomfort around the eyes, headache are clinical manifestations of what?
Glaucoma
is glaucoma curable using medical management?
No
for glaucoma, laser burns are applied to the inner surface of the trabecular meshwork to open the intratrabecular spaces and widen the canal of Schlemm.
Laser Trabeculoplasty
for pupillary block glaucoma, an opening is made in the iris to eliminate the pupillary block.
laser iridotomy
for chronic glaucoma are used to create an opening or fistula in the trabecular meshwork to drain aqueous humor from the anterior chamber to the subconjunctival space into a bleb.
Filtering procedures
is the standard filtering technique used to remove part of the trabecular meshwork.
Trabeculectomy
usually bilateral, but one eye may be more severely affected that the other
open-angle glaucoma
open-angle glaucoma: optic nerve damage, visual field defects, IOP > 21 mmHG, possible ocular pain, headache, and halos
Primary open-angle glaucoma (POAC)
open angle glaucoma: IOP < or equal 21mmHg. Opic nerve damage, visual fields defects
Normal tension glaucoma
open angle glaucoma: Elevated IOP, oculat pain or headache
Ocular hypertension
obstruction in aqueous humor outflow due to the complete or partial closure of the angle from the forward shift of the peripheral iris to the trabecula. The obstruction results in an increased IOP.
Angle-closure (pupillary block) glaucoma
Angle-closure (pupillary block) glaucoma: rapidly progressive visual impairment, periocular pain, conjunctival hyperemia, and congestion
Acute angle-closure glaucoma
Angle-closure (pupillary block) glaucoma: transient blurring of vision, halos around lights; temporal headaches and/or ocular pain; pupil may be semidilated.
Subacute angle-closure glaucoma
Angle-closure (pupillary block) glaucoma: Progression of glaucomatous cupping and significant visual field loss; IOP may be normal or elevated; ocular pain and headache
Chronic angle-closure glaucoma
This condition has clinical manifestations of: Painless, blurry vision, dimmer perception of surroundings, light scattering
Cataracts
TRUE OR FALSE: NO NON—SURGICAL treatment cures cataracts or prevents
age-related cataracts.
True
Inherited as autosomal dominant traits and manifest when the person is about 20 years Decreased vision due to: irregular corneal surface and corneal deposits.
Corneal Dystrophies
formation of blisters that cause pain and discomfort on rupturing
Keratopathy
a condition characterized by a conical protuberance of the cornea with progressive thinning on protrusion and irregular astigmatism
Keratoconus
the most relevant to common retinal disorders.
Two innermost layers, the sensory retina and the retinal pigment epithelium (RPE)
refers to the separation of the RPE from the sensory layer; four types: rhegmatogenous, traction, a combination of rhegmatogenous and traction, and exudative
Retinal detachment
retinal detachment: is the most common form. In this condition, a hole or tear develops in the sensory retina, allowing some of the liquid vitreous to seep through the sensory retina and detach it from the RPE
Rhegmatogenous detachment
Retinal detachment: caused hemorrhages and fibrous proliferation associated with diabetic retinopathy, vitreous hemorrhage.
Traction detachment
Retinal detachment: are the result of the production of a serous fluid under the retina from the choroid. Conditions such as uveitis and macular degeneration may cause the production of this serous fluid.
Exudative retinal detachment
sensation of a shade or curtain coming across the vision of one eye, cobwebs, bright
flashing lights, or the sudden onset of a great number of floaters, no pain.
Retinal detachment
The retinal surgeon compresses the sclera (often with a scleral buckle or a silicone band to indent the scleral wall from the outside of the eye and bring the two retinal layers in contact with each other.
Scleral buckle
intraocular procedure in which 1- to 4- mm incisions are made at the pars plana.
vitrectomy
A vitrectomy is an intraocular procedure in
which 1- to 4- mm incisions are made at the pars plana. One incision allows the introduction of a light source, and another incision serves as the portal for the vitrectomy instrument.
Pars Plana Vitrectomy
is the most common cause of visual loss in people older than 60 years of age in
developed countries; 2 types: dry and wet
Age-related macular degeneration (AMD)
Type of AMD: presence of drusen, outside of macula: no symptom, within macula: vision blurring
Dry (Non neovascular and non exudative)
Type of AMD: may have an abrupt onset. Patients report that straight lines appear crooked and distorted or that letters in words appear broken.
Wet (neovascular, exudative)
are given to patients to use in their
homes to monitor for a sudden onset or distortion of vision
Amsler grids
is the leading cause of blindness among children and young adults, especially male trauma victims.
Ocular trauma
a common cause of corneal abrasion
Contact lens wear
ocular pain on exposure to light)
Photophobia
edema of the conjunctiva
Hemorrhagic chemosis
hemorrhage within the chamber)
Hyphema
complete removal of the eyeball and part of the optic nerve
Primary enucleation
an inflammation created in the uninjured eye by the affected eye that can result in blindness of the uninjured eye
Sympathetic ophthalmia
are prescribed to reduce inflammation
topical corticosteroids
is a deficiency in the production of any of the aqueous, mucin, or lipid tear film components; most common complaint in dry eye syndrome is a scratchy or foreign body sensation
Dry eye syndrome, or keratoconjunctivitis sicca
is an effective agent that increases tear production and is used once daily
Cyclosporine ophthalmic emulsion (Restasis)
(inflammation of the conjunctiva)
Conjunctivitis
is the most common ocular disease worldwide. It is characterized by a pink appearance (hence the common term pink eye) because of subconjunctival blood vessel congestion.
Conjuctivitis
may be unilateral or bilateral, but the infection usually starts in one eye and then
spreads to the other eye by hand contact.
Conjunctivitis
3 Types of Conjunctivitis
Microbial, Allergic, Toxic
Conjunctivitis: is almost always self-limiting, lasting 2 weeks if left untreated; most common causative microorganisms are Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus;
Acute bacterial conjunctivitis
includes trachoma is treated with
broad-spectrum antibiotics are administered topically and systemically.
Chlamydial conjunctivitis
conjunctivitis: not responsive to any treatment. Cold compresses may alleviate some symptoms
Viral
Acute suppurative infection of the glands of the eyelids caused by Staphylococcus aureis.
Hordeolum (stye)
Sterile inflammatory process involving chronic granulomatous inflammation od the meibomian glands,
Chalazion
Chronic bilateral inflammation of the eyelid margins .here are two types: staphylococcal and sebortheic. Staphylococcal type is usually ulcerative and is more serious due to the involvement of the base of hair follicles. Permanent scarring can result.
Blepharitis
is the removal of the entire eye and part of the optic nerve.
Enucleation
involves the surgical removal of the intraocular contents through an incision or opening in the cornea or sclera
Evisceration
the removal of the eyelids, the eye, and various amounts of orbital contents. It is indicated in malignancies in the orbit that are life threatening or when more conservative modalities of treatment have failed or are inappropriate.
Exenteration
dynamics of ocular pharmacokinetics
absorption, distribution, metabolism, and excretion
conjunctival sac can hold only:
50 uL
prevent high ocular tissue concentration of most ophthalmic medications because they separate the bloodstream from the ocular tissues and keep foreign substances from entering the eye, thereby limiting a medication’s efficacy.
Blood–ocular barriers
pupil dilation
Mydriasis
is the main objective of the
administration of mydriatic and cycloplegic agents
Mydriasis, or pupil dilation,
administered to paralyze the iris sphincter.
Cycloplegic medications
medications to control ocular hypersensitivity reactions.
Antiallergy Medications like corticosteroids
used to cleanse the external lids to maintain lid
hygiene, to irrigate the external corneal surface to regain normal pH (eg, in chemical
burns), to irrigate the corneal surface to eliminate debris, or to inflate the globe
intraoperatively
Ocular Irrigants and Lubricants-
The extraocular muscles
4 rectus: superior rectus, inferior rectus, lateral rectus, and medial rectus muscles; 2 oblique: superior and inferior oblique
