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NUR 475 – FNP III

HEENT

Normal Vision Changes with Aging: Diagnosis and Management

VISUAL CHANGE / FUNCTIONAL CORRELATES / MANAGEMENT
Decrease in visual acuity / Performing all visual tasks / Increase illumination
Increase contrast
Presbyopia / Difficulty with near point tasks / Corrective eyeglasses
Increase illumination
Decrease in contrast sensitivity / Difficulty seeing under conditions of poor lighter (e.g., night driving, church) and poor contrast (e.g., reading a newspaper) / Filters
Magnification
Illumination
Decrease in dark adaptation / Problems with tunnels, movie theaters, night driving / Sunglasses when outdoors
Take a moment to dark/light adapt before trying to walk
Delayed recovery from glare / Problems with headlights, decreased visual functioning on sunny days / Sunglasses (but not for night driving)
Antireflective lens coating
Hats, visors
Less fluorescent lighting

(Source: Carter, T.L. (September 1994). “Age-related vision changes: A primary care guide. Geriatrics, 49(9), 37-45.)

Classifications of Visual Impairment

CLASSIFICATION / DEFINITION
Legal blindness / Best visual acuity ≤ 20/200 in the better eye or
Visual filed ≤ 20o
Partially sighted / Best visual acuity ≤ 20/70 in the better eye or
Visual filed ≤ 30o
Functionally visually impaired / When activities of daily living are affected
Best visual acuity ≤ 20/50

(Source: Carter, T.L. (September 1994). “Age-related vision changes: A primary care guide. Geriatrics, 49(9), 37-45.

The four most prevalent age-related ocular diseases and the four leading causes of low vision in the US are:

  • Macular degeneration
  • Open-angle glaucoma
  • Cataract
  • Diabetic retinopathy

Age-Related Macular Degeneration (AMD)

  • Leading cause of irreversible blindness in people 50 years of age or older in the developed world
  • Prevalence: 30% at age 75+; currently 8 million Americans have AMD
  • Risk factors: advanced age, white race, heredity, systemic hypertension, and a history of smoking
  • Only 10% of individuals with macular degeneration have significant functional visual loss.
  • Since the macula is the area for central vision and provides the highest degree of visual resolution, deterioration of this portion of the retina leads to the loss of central vision.
  • Leads to deficits in form recognition and light sensitivity
  • Types of macular degeneration:
  • Dry (non-exudative) macular degeneration
  • Most common (80-90% of cases)
  • Manifested by a progressive loss of retinal and pigment epithelium and gradually increasing central blind spot
  • Untreatable
  • Wet (exudative, or neovascular) macular degeneration
  • Due to accumulation of subretinal blood or exudates (from neovascularization)
  • Can have an acute onset with decreased central vision, metamorphopsia (blurred vision), or a dark spot in the central vision (central scotoma)
  • If found early and not yet in fovea, laser phocoagulation therapy is possible
  • Management (Source: Jager, RD, Mieler, WF, & Miller, JW. (June 12, 2008). NEJM, 358(24), 2606-2617)
  • Antioxidant supplementation (Preser-Vision, Bausch & Lomb): Vitamins C & E, beta carotene, zinc oxide, and cupric oxide.
  • NOTE: Not recommended for those with any smoking history due to increased risk of lung cancer with beta-carotene supplements in current or former smokers. (Source: Gohel, PS, Mandava, N, Olson, JL, & Durairaj, VK.(April 2008). The American Journal of Medicine, 121(4), 279-281.)
  • Lifestyle and dietary modifications
  • Quit smoking
  • Decrease dietary intake of fat
  • Maintain healthy weight and BP
  • Increase dietary intake of antioxidants through foods such as green leafy vegetables, whole grains, fish, and nuts
  • Intravitreal antiangiogenic therapy (injection of antiangiogenic agents directly into the vitreous)
  • Visual rehabilitation for macular degeneration
  • Self-monitor central vision (Amsler’s chart/Amsler’s grid)
  • Magnify the area of central vision
  • Hand-held ocular lenses
  • Video enlargement
  • Microfilm reading systems
  • Increase field illumination

Glaucoma

Definition:

  • Formerly: increased IOP that leads to blindness
  • Now: A group of conditions characterized by eye changes usually associated with increased IOP
  • A progressive optic neuropathy involving characteristic structural damage to the optic nerve and characteristic visual field defects

Changes in IOP:

  • Normal IOP: 10-20 mm Hg and IOP difference of less than 3 mm Hg between eyes
  • Pressures of 20-30 mm Hg will cause gradual damage over the years due to atrophy of the retinal ganglion cell layer.
  • Damage seen on fundoscopy:
  • optic disk shows cupping of the optic nerve head and a decrease in the diameter of the optic vessels
  • as the orange-red area of nerve fiber axons shrinks, the lighter cup in the center grows and the visual field of the patient becomes smaller
  • Changes in the disk are reflected in the patient’s decreased visual acuity
  • Pressures of 40-50 mm Hg can cause much more rapid vision loss due to ischemia of the optic nerve and retinal structures and may even result in vascular occlusion.
  • For example of how vision can change with glaucoma:

Incidence:

  • 5 million people worldwide are blind from glaucoma (World Health Organization)
  • People diagnosed with glaucoma in Third World countries are more likely to progress t blindness due to lack of treatment options
  • In US: 2 million diagnosed with glaucoma
  • High predominance in:
  • African Americans and Asians than Caucasians
  • Females more than males
  • Between ages 55 and 70

Conventional pathway for normal flow of aqueous humor: fluid passes from the posterior chamber through the papillary aperture to the anterior chamber, then to the trabecular meshwork, exiting through Schlemm’s canal and finally into the episleral veins, which drain into the venous system via the facial vein.

Both diagrams taken from: website of National Glaucoma Research, a program of the American Health Assistance Foundation at

Glaucoma Terminology

(Erwin, EA & Mendelson, M. (July 2005) Acute presentations of glaucoma. Emergency Medicine, 14-21.)

Angle of anterior chamber / Angle created by cornea, iris, and trabecular meshwork
Primary glaucoma / Idiopathic increase in IOP
Secondary glaucoma / Increase in IOP from known disease
Open-angle glaucoma / Insidious increase in IOP that can slowly progress to blindness
Acute angle-closure glaucoma / Medical emergency marked by abrupt increase in IOP that can rapidly progress to optic nerve damage and nerve death

A brief note on secondary glaucoma:

  • many secondary causes are rare
  • exfoliative syndrome and pigment dispersion syndrome
  • debris and granules are caught up in the trabecular meshwork and block the flow of the aqueous humor
  • lens-induced glaucoma (lens subluxation or dislocation)
  • structures which drain aqueous humor collapse without the lens support
  • ocular inflammatory disease (can occur with herpes zoster ophthalmicus)
  • intraocular tumors
  • ** topical or systemic corticosteroids

Open-Angle Glaucoma

  • Most common form of glaucoma
  • Primary type
  • Slow, usually painless process that occurs over a long period of time
  • Diagnosis usually made only after screening of patients in high-risk populations
  • > 40 years of age
  • Obese patients
  • Patients with diabetes, HTN
  • Since flow of aqueous humor is a passive process, increased venous pressure can inhibit the normal removal of aqueous humor.
  • History of ocular or severe head trauma
  • Family history of glaucoma
  • Many elderly patients are being treated for open-angle glaucoma and may present with adverse effects from their medications.
  • Treatment: typically topical medications are used (see next page)

Class / Local side effects / Systemic side effects / Mechanism of action
Cap or label color
Trade (generic) med names
Beta-adrenergic blocking agents /
  • Minimal transient ocular discomfort
/
  • Bradycardia
  • Impotence
  • Fatigue
  • Depression
  • Exacerbation of asthma/COPD
Use with caution in patients with heart block, heart failure, asthma, COPD, or depression / Reduces aqueous humor production
Yellow (5%) or light blue (0.25%)
Betagan (levobunolol)
Timoptic, Betimol (timolol)
Betoptic (betaxolol)
OptiPranolol (metipranolol)
carteolol
Alpha-adrenergic agents /
  • Redness
  • Itching
  • Edema
/
  • Dry mouth
  • Fatigue
Contraindicated with MAOIs (or within 14 days of MAOI) / Reduce aqueous humor production and increases outflow of aqueous humor
Purple
Alphagan (brimonidine)
Iopidine (apraclonidine)
Carbonic anhydrase inhibitors /
  • Stinging
  • Burning
  • Irritation
/
  • Minimal transient bitter taste
Use with caution in patients with liver disease, severe renal disease, adrenocortical insufficiency, or severe COPD / Decreases aqueous humor production
Orange or white
Trusopt (dorzolamide)
Azopt (brinzolamide)
Prostaglandin F2-alpha analogs /
  • Redness
  • Stinging
  • Darkening of the iris
  • Darkening of periorbital skin pigment
  • Longer and thicker eyelashes
/ Negligible system side effects
[Note: bimatoprost also marketed as Latisse, for eyelash hypotrichosis] / Increases the outflow of aqueous humor
Teal
Xalatan (latanoprost)
Lumigan (bimatoprost)
Travatan (travoprost)
Miotics /
  • Blurred vision (especially in younger patients)
  • Tearing
/ Brow aches / Increases the outflow of aqueous humor
Green
IsoptoCarpine, Pilocar (pilocarpine)

Compiled from:

Erwin, EA & Mendelson, M. (July 2005). Acute presentations of glaucoma. Emergency Medicine, 14-21.andKowing, D & Kester, E., (July 2007). Keep an eye out for glaucoma. The Nurse Practitioner, 18-23.

If medications are not sufficient to reduce the IOP, laser surgery is the usual next step.

Depending in the type of procedure, laser surgery may be used for open-angle, angle-closure or neovascular glaucoma. A laser is directed toward the trabecular meshwork, the iris, ciliary body or the retina and is used in various ways to reduce eye pressure. Laser surgery is performed on an outpatient basis in an eye doctor’s office or clinic after the eye has been numbed.

There are several types of laser surgeries:

  • Trabeculoplastyis often used to treat open-angle glaucoma. In argon laser trabeculoplasty (ALT), a high-energy laser is aimed at the trabecular meshwork to open areas in these clogged canals. These openings allow fluid to bypass drainage canals and flow out of the eye. In selective laser trabeculoplasty (SLT) a low-energy laser treats specific cells in the trabecular meshwork. Because it affects only certain cells without causing collateral tissue damage, SLT can potentially be repeated.
  • Laser peripheral iridotomy (LPI) is frequently used to treat angle-closure glaucoma, in which the angle between the iris and the cornea is too small and blocks fluid flow out of the eye. In LPI, a laser creates a small hole in the iris to allow fluid drainage.
  • Cyclophotocoagulation is usually used to treat more aggressive or advanced open-angle glaucoma that has not responded to other therapies. A laser is directed through the sclera or endoscopically at the eye fluid-producing ciliary body. This helps decrease the production of fluid and lower eye pressure. Multiple treatments are often required.
  • Scatter panretinal photocoagulation is a laser procedure that destroys abnormal blood vessels in the retina which are associated with neovascular glaucoma.

The most common side effects of laser surgery are temporary eye irritation and blurred vision. There is a small risk of developing cataracts.

Currently, laser surgery is the most frequently used procedure to treat glaucoma. It normally lowers eye pressure, but the length of time that pressure remains low depends on many factors, including age of the patient, the type of glaucoma and other medical conditions that may be present. In many cases, continued medication is necessary, but potentially in lower amounts.

(Content on laser surgery taken from:

Acute Angle-Closure Glaucoma

  • Relatively uncommon cause of glaucoma
  • Ocular emergency
  • In patients prone to acute angle-closure glaucoma, the anterior angle of the eye is narrower than normal, and the conventional route of aqueous humor outflow is more easily blocked by occlusion of the trabecular meshwork by the iris and the cornea.
  • IOP can rise to 80 mm Hg, leading to permanent, rapid optic nerve injury or death
  • Usual chief complaint: headache or eye pain and a significant decrease in visual acuity
  • Also: nausea, vomiting, red/painful/swollen eye
  • Systemic effects from vagal nerve stimulation: diffuse abdominal pain, N, V
  • History: patients may recall episodes of eye pain at night or in dark rooms or theaters, during periods of emotional upset, or after receiving an anticholinergic or sympathomimetic medication such as eye drops given prior to an eye exam.
  • These episodes may have been relieved with sleep or bright lights, since both cause miosis, pulling open the anterior chamber angle and allowing aqueous humor to flow out.
  • Physical exam
  • Mid-dilated fixed pupil (commonly oval-shaped)
  • Hazy cornea (can cause patient to see halos around lights)
  • Tearing
  • Conjunctival injection (red eye)
  • Measurement of ocular pressure in both eyes with tonometry
  • Schiotz tonometer
  • Tono-Pen
  • Fundoscopic exam: glaucomatous cupping (ratio of the yellow optic cup to the darker pigmented optic disk increases), retinal vessel displacement, and splinter or flame hemorrhages
  • Visual acuity testing
  • Differential diagnosis
  • Corneal abrasion or lacteration
  • Conjunctivitis
  • Iritis
  • Uveitis
  • Herpes zoster
  • Periorbital cellulitis
  • Retinal artery occlusion
  • Cavernous sinal thrombosis
  • Temporal arteritis
  • Sinusitis
  • Migraine headache
  • Treatment:
  • emergent consultation with an ophthalmologist
  • combination of medications used for open-angle glaucoma
  • other meds: optic steroids, miotic agents, NSAIDS, hyperosmotic agents
  • followed by peripheral irdiotomy or iridectomy
  • Patient education: warn patient that the other eye is also at risk for an acute angle-closure glaucoma episode; emphasize seeking immediate care

Cataracts

  • An opacity in the normally transparent focusing lens inside the eye that prevents light rays from being focused clearly on the retina
  • Blue light most distorted; may help to use yellow-tinted filters on corrective lenses
  • One of the most important causes of reversible blindness in elderly persons
  • Estimated that number of Americans with cataracts will increase by approximately 50% in the next 20 years as the population ages
  • 50% of those over age 40 show signs of lens clouding
  • Leading cause of low vision among whites, blacks, and Hispanics
  • Causes:
  • Aging
  • Cumulative UV-B light exposure
  • Intraocular diseases (uveitis, intraocular malignancies, retinitis pigmentosa, retinal detachment)
  • Trauma
  • Drugs (topical and systemic steroids, phenothiazines, phospholine iodide eyedrops)
  • Endocrine/metabolic disorders (diabetes mellitus, hypoparathyroidism, hypothyroidism, galactosemia)
  • Congenital
  • Treatment: cataract surgery for removal of the cataractous lens and implantation of intraocular lens
  • When to have cataract surgery: typically when decreased vision interferes with the patient’s ability to function in his/her daily living pattern, occupation, lifestyle and desired or required activities.
  • Surgery is not indicated just because a cataract is present, since it may be mild and well tolerated.
  • The surgery may be recommended if the cataract is interfering with diagnosis or treatment of other ocular diseases such as diabetic retinopathy or potential intraocular malignancy
  • Success rate 80-90%
  • Potential complications: wet macular degeneration (usually had early-stage MD lesions pre-op), posterior capsular opacification (easily correct with laser procedure), retinal detachment

Diabetic Retinopathy

(Source: Carter, T.L. (September 1994). “Age-related vision changes: A primary care guide. Geriatrics, 49(9), 37-45.

  • Symptoms: decreased acuity, contrast sensitivity, color perception, and dark/light adaptation, as well as glare disability and scotomas
  • Key in preventing visual impairment: early diagnosis and treatment
  • All people with diabetes should have a yearly retinal exam through a dilated pupil
  • Nonproliferative diabetic retinopathy
  • Clinical manifestations: dilated retinal veins, microaneurysm, intraretinal hemorrhages, hard (lipid) exudates, cotton wool spots (microinfarcts) and macular edema
  • Patient needs to be monitored for macular edema and proliferative changes every 3-6 months
  • Proliferative diabetic retinopathy
  • Clinical signs: neovascularization, vascular fibrosis and preretinal as well as vitreous hemorrhages
  • Managed with laser photocoagulation

Vision Loss in Older Persons (> age 65)

  • Associated with depression, social isolation, falls, and medication errors
  • Should be screened every 1-2 years with attention to specific disorders such as diabetic retinopathy, refractive error, cataracts, glaucoma, and age-related macular degeneration
  • Vision-related adverse effects of commonly used medications, such as amiodarone or phosphodiesterase inhibitors, should be considered when evaluating vision problems
  • Prompt recognition and management of sudden vision loss can be vision saving.
  • Aggressive medical management of diabetes, hypertension, and hyperlipidemia; encouraging smoking cessation; reducing ultraviolet light exposure; and appropriate response to medication adverse effects can preserve and protect vision.

Drugs that are Toxic to the Eyes(from publication of The American Academy of Ophthalmology)

  • Drugs that cause irreversible damage in recommended doses
  • Corticosteroids (cause cataracts)
  • Isotretinoin (Accutane) (can cause pseudo-tumor cerebri)
  • Hydroxychloroquine (Plaquenil) (causes “bull-s eye” pericentral scotoma)
  • Ethambutol (can cause visual loss)
  • Drugs that cause reversible damage in recommended doses (cause paralysis of accommodation, so that patients cannot focus on near targets)
  • Antipsychotics
  • Antihistamines
  • Tricyclic antidepressants
  • Antispasmodics
  • Some centrally-acting drugs for Parkinson’s Disease
  • Drugs that cause damage only above recommended doses or serum levels
  • Digoxin (with dig toxicity, may have yellowish-orange vision; usually returns to normal with normal serum dig level)
  • Phenytoin (Dilantin) can have blurred vision
  • Carbamazepine (Tegretol) can have blurred vision

Eye Pain


Iritis

  • Most common is anterior, confined to the iris
  • Acute iritis is the more common form seen by primary care providers (vs. chronic)
  • Occurs in young adults
  • Causes: ankylosing spondylitis, Reiter’s syndrome, sarcoidosis, collagen diseases (RA, SLE), TB, syphilis, toxoplasmosis
  • Manifests as ocular pain, redness, photophobia, and blurred
  • Tearing may be present, but neither purulent discharge nor a history of trauma or presence of foreign body is elicited
  • Exam: pupil tends to be small, may be irregular because the iris has adhered to the anterior lens
  • Conjunctiva is hyperemic = ciliary flush
  • Dx: confirmed by presence of inflammatory cells
  • The cells, due to the primary inflammation, usually float in the anterior chamber (graded on a scale of 0 to 4+)
  • The inflammatory cells may layer in the anterior chamber
  • The inflamed vessels allow protein to leak into the aqueous fluid, making the fluid appear translucent when viewed with a slit lamp
  • Treatment: targeted at decreasing inflammation and alleviating pain
  • Mydriatic agents (such as phenylephrine) to dilate pupil
  • Cycloplegic agents (such as atropine) to ease pain and photophobia
  • Corticosteroid drops to suppress the inflammation

Floaters and Flashes