Cataract & Glaucoma Flashcards
An area of opacity within the lens
Cataract
Leading causes of reversible vision loss worldwide
Cataract
What is cataract?
-An area of opacity within the lens
- Leading causes of reversible vision loss worldwide
Etiology of cataract
-age (senile cataracts)
- trauma (blunt or penetrating)
- congenital factors (maternal rubella)
- radiation/ultraviolet exposure
- topical corticosteroids
- Diabetes mellitus
Pathophysiology of Cataract
Altered metabolic process
- accumulation of water in the lens fiber structure
- affectation of lens transparency
What is the clinical manifestations of cataract?
- Decrease in vision
- Visual decline
- Abnormal color perception
- Glaring of vision
- Secondary glaucoma
worse at night when the pupil dilates
glaring of vision
what is glaring of vision?
worse at night when the pupil dilates
this is due to increased IOP from enlarging lens
secondary glaucoma
what is secondary glaucoma?
due to increased IOP from enlarging lens
Diagnostics of Cataract
-Visual acuity test (Snellen Chart)
- Ophthalmoscopic exam
- Glare testing
-Slit-lamp microscopic examination
Non-surgical management of Cataract
-Prescription change for glasses
- Strong reading glasses or magnifiers
- Increased lighting
- Lifestyle adjustment
Surgical Management of Cataract
-Cataract extraction
- Phacoemulsification
An intraocular procedure
Cataract extraction
Removal of the lens of the eye and replacing it with an artificial lens (intraocular lens)
Cataract Extraction
What is cataract extraction?
-An intraocular procedure
- Removal of the lens of the eye and replacing it with an artificial lens (intraocular lens)
Modern-day cataract surgery
Phacoemulsification
The internal lens is emulsified using ultrasonic energy and replaced with an intraocular lens
Phacoemulsification
What is phacoemulsification?
The internal lens is emulsified using ultrasonic energy and replaced with an intraocular lens
Medical Management of Cataract
-Mydriatics
- Cycloplegic
An a-adrenergic agonist
mydriatics
produces pupillary dilation
mydriatics
example of mydriatic drug
Phenylephrine HCI (mydfrin)
What is mydriatics?
-an a-adrenergic agonist
-produces pupillary dilation
What is cycloplegic?
-an anticholinergic
- produces paralysis of accommodation (cycloplegia) causing pupillary dilation
produces paralysis of accommodation (cycloplegia) causing pupillary dilation
Cycloplegic
Example of cycloplegic drug
Tropicamide (mydriacyl)
Nursing Management of Cataract
- Maintain safety since patient has no depth perception in the next 24 hours
- Antioxidants vitamins (C&E) inhibit lens opacification
- Instruct about the feeling to scratch the operative. Give mild analgesics as ordered.
- Dark glasses to minimize photophobia when taking eye medications
- Monitor for signs of infection
characterized by elevated IOP
Glaucoma
second leading cause of visual loss
Glaucoma
early detection means
early detection prevents blindness
consequences of glaucoma
-optic nerve atrophy
- peripheral visual field loss
Etiology of Glaucoma
-Family history
- Age
- near-sightedness (myopia)
-diabetes
-Ethnicity (African descent)
the axial length increase leads to the tilting of the optic disc, causing damage to the axons in the lamina cribrosa
near sightedness (Myopia)
What is near-sightedness or myopia?
the axial length increase leads to the tilting of the optic disc, causing damage to the axons in the lamina cribrosa
Pathophysiology of Glaucoma
-Imbalance between the rate of aqueous production (inflow) and the rate of aqueous reabsorption (outflow)
-inflow is greater than outflow
- IOP increases
What is the function of aqueous humor?
-for lubrication
- one maintaining the pressure and the appearance of eyeball
-keeps your eye inflated and provides nourishment
2 types of glaucoma
- Primary Open-Angle Glaucoma
- Primary Angle-Closure Glaucoma
the most common type
primary open-angle glaucoma
outflow of aqueous humor is decreased in the trabecular meshwork
primary open-angle glaucoma
drainage channel becomes clogged, and damaged to the optic nerve
primary open-angle glaucoma
What is primary open-angle glaucoma?
-The most common type
- Outflow of aqueous humor is decreased in the trabecular meshwork
- Drainage channel becomes clogged, and damaged to the optic nerve
a reduction in the outflow of aqueous humor that results from angle closure
Primary angle-closure glaucoma
due to bulging of lens because of aging
Primary angle-closure glaucoma
What is primary angle-closure glaucoma?
-a reduction in the outflow of aqueous humor that results from angle closure
- due to bulging of lens because of aging
Clinical Manifestations of Glaucoma
- Frosted appearance of cornea
- Ocular redness
- Colored halos around lights
- Acute pain around the eye
- Symptoms are unnoticeable
- Tunnel Vision
a small center field can be seen
tunnel vision
due to cornel edema
frosted appearance of cornea
Diagnostics of Glaucoma
Tonometry
What is Tonometry?
-IOP measurement
What is the normal IOP?
10- 21 mmHg
Medical Management of Chronic Open-Angle Glaucoma
-B-adrenergic blockers
- Miotics
Mechanism of action of b-adrenergic blockers
decreases aqueous humor production
example of b-adrenergic blockers
Betaxolol (Betoptic)
decreases aqueous humor production
B-adrenergic blockers
A cholinergic
Miotics
Facilitating outflow of aqueous humor
Miotics
Example of Miotics
Carbachol (Isopto Carbachol)
Surgical Management of Glaucoma
-Trabeculectomy
- Argon Laser Trabeculoplasty
Also known as filtration surgery
Trabeculectomy
The gold standard surgery of Glaucoma
Trabeculectomy
The creation of a fistula connecting the anterior chamber and the subconjunctival space
Trabeculectomy
Success rate of Trabeculectomy is
75 to 85%
What is Trabeculectomy?
-aka as filtration surgery
- the gold standard surgery
- the creation of a fistula connecting the anterior chamber and the subconjunctival space
nonivasive procedure; topical anesthesia is given
Argon Loss Trabeculoplasty
decreases IOP (75%)
Argon Laser Trabeculoplasty
Laser stimulates scarring and contraction of the trabecular meshwork, which opens the outflow channels
Argon Laser Trabeculoplasty
corticosteroids are given post-surgery
Argon Laser Trabeculoplasty
Why corticosteroids are given after post argon laser trabeculoplasty surgery?
to prevent inflammation caused by scarring
What is Argon Laser Trabeculoplasty?
- noninvasive procedure; topical anesthesia is given
-decreases IOP (75%)
-Laser stimulates scarring and contraction of the trabecular meshwork, which opens the outflow channels
-corticosteroids are given post surgery
Nursing Management of Glaucoma
-Risk of vision loss must be taught especially as age increases
- Early detection and treatment
- Corticosteroids promote healing during post-operative period (trabeculectomy)
- Eye shield even while sleeping is imperative
- vigorous exercise are contraindicated
