Eye Flashcards
Layers of the eyeball
External layer (sclera) Middle layer (uvea) Innermost layer (retina)
refractive structures and media
Cornea
Aqueous humor
Lens
Vitreous body
external structures of the eye
Canthus
Conjunctivae
Lacrimal gland
punctum
emmetropia
the perfect refraction of the eye
hyperopia
occurs when the eye does not refract light enough (farsightedness)
myopia
occurs when the eye overrefracts or overbends the light (nearsightedness)
astigmatism
a refractive error caused by unevenly curved surfaces on or in the eye, especially of the cornea
Miosis
pupillary constriction.
mydriasis
is pupillary dilation.
accomadation
the process of maintaining a clear visual image when the gaze is shifted from a distant to a near object.
age related structural changes of the eye
Decreased eye muscle tone Ectropion and dry eye Arcus senilis (does not effect vision) Corneal changes Changes in color of sclera Less ability to dilate pupil More light needed for reading
age related functional changes of the eye
Lens yellows. Accommodation is gradually lost. Near point of vision increases (presbyopia). Far point decreases. Color perception decreases. Intraocular pressure increases.
visual problems / health promotion of the eye
Glaucoma and Diabetic retinopathy are significant causes of preventable visual impairment
Ocular trauma can lead to blindness
Casual care of contact lenses
Women of childbearing age should be immunized against rubella to prevent congenital blindness
Genetically transmitted syndromes and conditions often have ocular manifestations
health promotion and maintenance of the eye
Education is important to preserve eye function
Protection
Nutrition
Importance of regular eye exams
common eye myths
Children outgrow crossed eyes
Night vision will improve by eating more carrots
Reading in dim light for long periods can harm the eye
Watching TV is bad for the eyes
Wearing glasses makes you dependent on them
People with weak eyes should rest them to strengthen them
Older people who have trouble seeing should not use their eyes too much because they wear out sooner
applying eye oitments
Common ophthalmic antibiotics are polymixin B, Bacitracin and Gentamycin
Ointment is placed into exposed conjuntival sac from inner canthus to outer canthus being careful to avoid touching the eyelashes
administration of eye drops
Wash hands
Tilt head back and look toward ceiling
Pull lower lid gently down and out to expose the conjunctiva and create a sac
Bring dropper from the side and apply eye drops. Avoid touching eyelashes, conjunctiva, and the surface of the eye
Close both eyes gently. Do not squeeze them tightly or medication will be expelled
Apply slight pressure at inner canthus to decrease systemic absorption of the med
If more than 1 drop is given, wait 2 to 5 minutes before applying the second drop
assessment of the eye
Patient history Nutrition history Vitamin deficiencies Family history and genetic risk Current health problems Near vision Visual field Extraocular muscle function Color vision
physical and diagnostic assessment of the eye
Physical Assessment Head positioning, squinting, etc Symmetry Eyebrows/lashes Sclera and cornea Pupils Diagnostics Labs Imaging Other (such as corneal staining, slit lamp exam, ophthalmoscopy, etc..)
cataract
Clouding and blurring of the lens distort the image and color projected onto the retina.
As cataract matures, opacity makes it difficult to see the retina.
Visual acuity is restricted.
No pain or eye redness is associated with age-related cataracts.
symptoms of cataracts
Painless blurry vision is characteristic
Patient perceives surroundings as dimmer—as if glasses need cleaning.
Light scattering is common and patient experiences a decrease in contrast sensitivity, sensitivity to glare and a decrease in visual acuity
May have diplopia and altered color perception.
There is reduced light transmission
Secondary glaucoma can occur if the lens enlarges
cataract surgery
Preoperative Pre-op education Consent Assessment Intraoperative Extraction and replacement of lens Postoperative Antibiotics/steriods Care meds
postoperative care of cataracts
Antibiotics are given subconjunctivally. Eye is unpatched. Discharge usually occurs within 1 hr with dark glasses. Instill antibiotic-steroid eyedrops. Mild itching is normal. Pain indicates a complication. Reduce IOP. Prevent infection. Assess for bleeding.
community based care of cataracts
Home care management Adaptive equipment Assistance to instill eye meds Health teaching Close adherence for best outcome Teach s/s of complications Activity hygiene Health care resources Arrange for support and help at home Someone to help with instilling meds
glaucoma
Group of ocular diseases resulting in increased IOP
Common cause of blindness
Age-related
Usually painless
Patient unaware of a gradual reduction in vision
Primary open-angle glaucoma
Angle-closure glaucoma
acute angle closure glaucoma
the onset is acute and the patient will have sudden, severe pain around the eyes that will radiate over the face. The person will have headache or brow pain and N/V may occur. Other s/s may include seeing halos around lights, sudden blurred vision with a decreased light perception. The sclera may appear reddened and the cornea foggy.
clinical manifestations of glaucoma
Cupping and atrophy of the optic disc; disc wider and deeper and turns white or gray
Visual field measurement
Headache or brow pain, nausea and vomiting, colored halos around lights, and sudden blurred vision with decreased light perception
diagnostic tests for glaucoma
Tonometry Measures IOP Perimetry Visual field testing Gonioscopy Assess whether open or closed angle Optic nerve imaging Visualizes the optic nerve
diabetic retinopathy
Retinal blood vessel complication
Retinopathy worsened with poor glucose control
Background diabetic retinopathy
Microaneurysms
Proliferative diabetic retinopathy
Laser therapy
Vitrectomy performed if frequent bleeding into the vitreous occurs
macular degeneration
The macula—the area of central vision—deteriorates.
Degeneration can be atrophic age-related (dry) or exudative (wet).
Rod and cone photoreceptors die.
Central vision declines; patient describes “mild blurring” and “distortion.”
dry macular degeneration
Dry AMD No cure Management based on slowing progression Maximize what vision patient has left Nutrition therapy Antioxidants, B12, lutein, zeaxanthin Wet AMD
Dry AMD
85% to 90% of AMD have dry or non exudative type.
Outer layers of retina break down and druzen forms.
When druzen is outside of macular area, patient’s generally have no symptoms.
Druzens can coalesce causing gradual loss of central vision when within the macula.
At first there is a gradual blurring of vision that patient’s notice when reading. There can be a missing in words, blank spots and loss of central vision.
There is no know treatment that can slow or cure the type of AMD.
wet AMD
May have an abrupt onset.
Is characterized by the development of an abnormal choroidal neovascular network beneath the macula. These vessels leak fluid and bleed, causing edema and the development of fibrosis.
Visual changes can occur rapidly. Straight lines appear crooked and distorted. The resulting macular scar causes loss of central vision.
Some can be treated with laser therapy to stop leaking but vision can be affected by treatment and abnormal vessels can grow back.
medical management of AMD
Nutritional supplements: antioxidant vitamins ( Vitamin C, E, and betacarotene) and Zinc may reduce the impact of AMD in some people.
Photodynamic Therapy (PDT )-Use of Verteporfin, a photosensitive dye, and laser therapy.
Macular Translocation
nursing management of AMD
Teaching regarding disease process, treatments, use of antioxidants, medical follow-up.
Give Amsler grid to patients for home monitoring
Teach about use of bright lighting and magnification devices.
Encourage smoking cessation and protection of eyes from the sun.
Low vision counseling services
