Exam 4 Flashcards
Hyperopia
Farsightedness, occurs when the eye doesn’t bend light enough
Myopia
Nearsightedness, occurs when the eye overbends light
Refraction
Bending light rays into the eye to the retina and reflecting back out so you can see an image
Emmetropia
Perfect refraction of the eye, 20/20 vision
Astigmatism
Refractive error caused by uneven curved surfaces in the eye, usually the cornea. The uneven surfaces distort vision
Miosis
Pupillary constriction
Mydriasis
Pupillary dilation
Older adults cornea
Flattens and blurs vision, worsens astigmatism. Encourage them to wear corrective lenses for best vision
Older adults’ ocular muscles reduce in strength, making it harder to maintain an upward gaze/maintain a single image. What do you tell them?
Normal, re-focus your gaze frequently to maintain a single image.
Older adults lens
- Hardens, compacts, forms cataracts, yellows
- Elasticity is lost, making the point of best vision farther away
- Encourage wearing glasses and yearly eye exams
Older adults iris
- Decreases in ability to dilate resulting in small pupils and poor adaption to darkness
- Teach good lighting to avoid falls
Older adults color vision
- Difficulty in discriminating among greens, blues, and violets
- Don’t use “dipstick” or other color indicator monitors of health status
- More light is needed to stimulate photoreceptors
Tear production in older adults
- Reduced, resulting in dry eyes, discomfort, increased risk for corneal damage/eye infections (more common in women)
- Teach pt to use saline eyedrops on a schedule, increase humidity in the home
Arcus senilis
An opaque, bluish white ring on the outer edge of cornea, caused by fat deposits. Very common with aging, doesn’t affect vision
Intraocular pressure in older adults
Slightly higher
Presbyopia
The point at which an object can be can be seen clearly decreases. Objects must be placed farther away. Commonly begins in 40s
Glaucoma
Increase intraocular pressure with aging causes hypoxia of photoreceptors and nerve fibers. Extra pressures push on capillaries and nerve fibers, preventing blood flow.
Cataract
A lens loses its transparency.
Lens
Circular convex structure behind the iris that bends rays of light through the pupil so they focus on the retina
Which drugs tend to dry the eye and increase IOP?
Decongestants and antihistamines
Systemic conditions which can affect vision
Diabetes, HTN, Lupus erythematosus, thyroid dysfunction, immune deficiency, sarcoidosis, cardia dz, multiple sclerosis, pregnancy
Vitamin A deficiency
Can cause dry eye, karatomalacia, blindness
Diet for eye health
Rich in fruit and red, orange, and dark green veggies. Lutein and beta carotene maintain retinal function
When do you notify an ophthalmologist immediately?
For sudden or persistent loss of vision within the past 48 hours, eye trauma, foreign body in eye, or sudden ocular pain.
What would a pt do with double vision?
Cock the head to the side to focus the two images into one or close one eye to see more clearly
Exophthalmos
Protrusion of the eye, “bulging”
Enophthalmos
Sunken appearance of eye
Anisocoria
Unequal pupils
Nystagmus
Involuntary rapid twitching of the eyeball. Normal finding for the far lateral gaze
Ishihara Chart
Tests color vision by showing numbers composed of dots of one color within a circle of dots of a different color. Test each eye seperately
Slit-Lamp Exam
Magnifies the anterior eye structures. Pt leans chin on a rest
Corneal Stain
Places fluorescein/topical dye into conjunctival sac. The dye outlines irregularities of corneal surface. Used for problems with contacts, and corneal traumas. Noninvasive, performed under aseptic conditions. Viewed through a blue filter, non intact areas of the cornea stain a bright green color
Tonometry
Measures IOP. Indicated for pts over 40, adults w/ family history of glaucoma should test twice a year.
Ophthalmoscopy
Views eye’s external and interior structures. Can be done by a nurse. Start 12-15 inches away. Red reflex is a reflection of the light on the retina. Absent red reflex may indicate a lens opacity or cloudiness of the vitreous. Avoid this test w/ a confused pt and use an interpreter for one who doesn’t speak your language.
Angiography
Provides detailed image of eye circulation. Used for assessing problems of retinal circulation or diagnosing intraocular tumors. Instill mydriatic eyedrops to dilate pupils 1 hour before the test. The dye may cause the skin to appear yellow or green for hours after test. IT eliminates through the urine, which will be bright green, drink fluids. Start an IV and inject 5 mL of 10% fluorescein. A digital camera takes pictures, takes only a few minutes. See results immediately.
Perimetry
Screens visual fields. Pt looks straight ahead and presses a control button when a light enters peripheral vision. Draws a “map” of peripheral vision.
Gonioscopy
Performed when a high IOP is found and determines whether open angle or closed angle glaucoma is present. Uses a special lens that eliminates the corneal curve, is painless, allows visualization of the angle where the iris meets the cornea.
Looks at the bony eye structures and EOM, used for detecting tumors in the orbital space. Not painful, must keep head still. Use contrast dye unless trauma is suspected
CT
Examines orbits and optic nerves, evaluates tumors. DO NOT use with metal in the eye
MRI
Most common method to measure IOP by an ophthalmologist
Goldman’s applanation tonometer with a slit lamp. IOP is usually hight in the morning but may peak at any time of the day. Record the time of procedure and tell pts to measure IOP at the same time each day.
When is easiest to examine the fundus?
When the room is dark bc the pupil will dilate.
How many times does a normal person blink per minute?
5-10
Inflammation of the eyelid edges
Blepharitis
Blepharitis is caused by what in older adults?
Dry eye syndrome
Seborrhea
Greasy and scaly, draining eye. Occurs with blepharitis
Pt’s eye is itchy, red, and burning.
Blepharitis
How to treat blepharitis
Warm compress, dilute baby shampoo, don’t rub
Turning inward of eyelid causing lashes to rub against eye. Corneal abrasion may result from constant irritation
Entropion
Turning outward and sagging of eyelid, reduces the washing action of tears, leads to cornea drying and ulcers
Ectropion
Entropion is caused by what?
Eyelid muscle spasms or post-trauma
Ectropion is caused by what?
Muscle relaxation or weakness w/ aging
Pt has pain and tears, conjunctiva is red, “feels something in their eye”
Entropion
Pt has constant tears and a sagging lower eyelid
Ectropion
How to treat entropion
Surgery tightens orbicular muscles and moves eyelid to normal position or prevents inward rotation. The pt wears an eyepatch after surgery until they’re seen by the ophthalmologist. Tell them to report any pain or drainage under the patch.
How to treat extropion
Surgery restores lid alignment, teaching is same as for entropion
Hordeolum
“Stye,” infection of sweat glands or sebaceous glands in eyelid, doesn’t affect vision. Caused by staph or strep, affects 1 eye at a time
Management of a stye
Warm compresses four times a day, antibacterial ointment. When the lesion opens, the pus (purulent material) drains and the pain subsides
When more than one topical eye drug is prescribed, pts should wait how long in between instillation of each drug?
10-15 minutes
Inflammation of a sebaceous gland in the eyelid that protrudes on the inner lid
Chalazion
Begins with redness and tenderness, followed by a gradual painless swelling. Pt has fatigue, light sensitivity, and excessive tears
Chalazion
Surgery for removing a chalazion
Keep a non pressure eye patch in place for 6 hours and then remove and apply warm compresses. Teach pt to report increasing redness, purulent drainage, or reduced vision to the ophthalmologist
Keratoconjunctivitis sicca
Dry eye syndrome
Results from changes in tear production/composition/distribution or drugs.
Dry eye syndrome
Injury to which cranial nerve inhibits tears?
VII
Pt has foreign body sensation in eye, burning and itching, photophobia, tears contain mucus strands and the corneal light reflex is dulled
Dry eye syndrome
How to treat allergic conjunctivitis
Vasoconstrictor or corticosteroid eyedrop
Bacterial conjunctivitis
“Pink eye,” caused by staph or Haemophilus influenza
Inflammation or infection of conjunctiva caused by exposure to allergens, irritants, infection/bacteria/virus and is very contagious
Conjunctivitis
Allergic conjunctivitis manifestations
Edema, sensation of burning, “bloodshot” eye appearance, excessive tears, itching.
Bacterial conjunctivitis manifestations
Blood vessel dilation, mild edema, tears, watery at first discharge and then it becomes thicker with shreds of mucus
Chronic conjunctivitis, similar symptoms of bacterial pink eye
Trachoma
Trachoma is caused by what
Chlamydia trachomatis
Scars the conjunctiva and is a common cause of preventable blindness, more often in warm, moist climates where sanitation is poor
Trachoma
Incubation period of trachoma
5-14 days
How to treat trachoma
“Big Daddy” antibiotics like erythromycin and tetracycline
Causes of corneal abrasion
Contact lens use, small foreign body, trauma, malnutrition, dry eye syndrome, cancer treatment
Why is corneal ulceration a medical emergency?
Lack of blood supply and permanent vision impairment
S/S of corneal abrasion
Pain, vision loss, photophobia, cloudy at injured site, open allowing germs in, can cause ulcerations
How to treat corneal abrasions
Antibiotic eye drops every hour for 24 hours to prevent vision loss
Degeneration of corneal tissue causing abnormal corneal shape, caused by trauma or genetic disorder
Keratoconus
Treatment for keratoconus when it obscures vision
Keratoplasty (corneal transplant) pt wears eye patch until next day when they return to surgeon. Tell pt to lie on the nonoperative side to reduce IOP. Wear shield at night or around kids/pets. DO NOT use ice pack.
What do you notify the ophthalmologist of after a keratoplasty?
Changes in vitals or drainage on the dressing.
Which drugs may need to be d/c before cataract surgery?
Drugs that affect blood clotting such as warfarin, aspirin, plavix
Opacity of the lens causing blurred vision
Cataract
Cataract risk factors
Aging, smoking, congenital, trauma/injury, poorly controlled diabetes, steroids
Senile cataracts
Due to aging
Immature cataracts
Partially cover lens
Mature cataracts
Cover entire lens
Optic neuropathy w/ gradual peripheral vision loss and increased IOP, leading cause of blindness, IOP increases due to problems with aqueous humor
Glaucoma
Risk factors for primary glaucoma
Age, more common in AA and hispanics
Risk factors for associated glaucoma
W/ another dz, diabetes, HTN, myopia
Risk factors for secondary glaucoma
Infection, trauma, cataract which pressed against and caused pressure
Open-angle glaucoma
Most common, normal angle, slow progression, partially obstructed aqueous humor, gradual vision loss. Late sign: night vision decreases, halos
Closed-angle glaucoma
Aqueous humor outflow blocked, abrupt onset, fast and permanent vision loss, unilateral, worse with pupil dilation. S/S: severe pain, abrupt change in vision, red conjunctiva, pupil fixed and non-reactive
Bleeding into vitreous cavity from aging, systemic dz, trauma. Caused by torn vessels bleeding, DM, HTN
Vitreous Hemorrhage
How to treat Vitreous Hemorrhage
Vitrectomy if the hemorrhage is still there weeks to months later and doesn’t absorb without treatment.
S/S of Vitreous Hemorrhage
Reduced visual acuity is the main sign. A mild hemorrhage may cause pt to see a red haze or floaters. A moderate hemorrhage may cause pt to see black streaks or tiny black dots. Severe hemorrhage may reduce visual acuity to hand motionThe eye has a reduced red reflex bc light rays do not reach the retina
Inflammation of iris, ciliary body, or choroid
Uveitis
Anterior uveitis
Can be caused by exposure to allergens, infectious agents, trauma, systemic dz (RA or herpes) and may follow local or systemic bacterial infection
Posterior uveitis
“Retinitis” or “Chorioretinitis” occurs from TB, syphilis, toxoplasmosis
S/S of uveitis
Reduced vision in the affected eye results from fluid, fibrin, and cells leaking into the vitreous cavity. The pupil is small, nonreactive, and irregularly shaped. Black dots are visible against the red background of the funds. Lesions appear as grayish yellow patches on the retinal surface.
Treatment of uveitis
Management: resting ciliary body with a cycloplegia drug to paralyze the ciliary muscles and dilate the pupil. Steroid drops are given hour to reduce inflammation and prevent adhesion of the iris to the cornea and lens.
Breakdown of macula that distorts central vision
Macular Degeneration
Types of Macular Degeneration
- Nonexudative (dry) no cure. Central vision declines, pts c/o mild luring and distortion
- Exudative (wet) Pts have a sudden decrease in vision after a serous detachment of pigment epithelium in the macula. Newly formed blood vessels invade this injured area and cause fluid and blood to collect under the macula like a blister resulting in scar formation and visual distortion
Treatment of macular degeneration
VEGFI (vascular endothelial growth factor inhibitors) are successful with wet degeneration
How to diagnose macular degeneration
Amsler
Separation of the retina from the pigmented vascular layer
Retinal Detachment, medical emergency!
Rhegmatogenous retinal detachment
Occur following a hole or tear in the retina caused by mechanical force, creating an opening for the vitreous to move under the retina
Traction retinal detachment
Occur when the retina is pulled away from the support tissue by bands of fibrous tissue in the vitreous
Exudative retinal detachment
Caused by fluid collecting under the retina. Often occur with a systemic dz or ocular tumors. No retinal break occurs
Risk factors for retinal detachment
Eye dz, cataract surgery, family hx, retinal detachment of the other eye
How to diagnose retinal detachment
On ophthalmoscopic examination, detachments are seen as gray bulges or folds in the retina that quiver.
Treatment for retinal detachment
Create an inflammatory response using a freezing probe (cryotherapy), a laser (photocoagulation) or a high-frequency current (diathermy) that will bind the retina and choroid together around the break. Surgery: scleral buckling
Hemorrhage in anterior chamber when force is applied to eye and breaks blood vessels
Hyphema
Traumatic contact from blunt object with eye pushed back into socket
Contusion
Most common malignant eye tumor in adults age 30-40
Ocular Melanoma
Ocular Melanoma is caused by what?
Exposure to UV light
Where can ocular melanomas spread?
Surrounding tissue and brain
S/S of ocular melanoma
Blurred vision may occur if the macular area is invaded. Visual acuity is reduced if the tumor grows inward toward the center of the eye from the choroid and alters the visual pathway. Increased IOP, iris color changed when the tumor infiltrates the iris.
Enucleation
Usually for ocular melanoma, surgical eye removal. A ball implant is inserted as a base for the socket prosthesis.
