Notes
Definition
- Is a condition marked by high intraocular pressure (IOP) that damages the optic nerve.
TYPES:
Chronic open-angle glaucoma
- Results from the gradual deterioration of the trabecular network that, as in the acute form, blocks drainage of aqueous humor and causes IOP to increase.
- If untreated, may result in degeneration of the optic nerve and visual field loss.
- It is the most common form of glaucoma, and its incidence increases with age.
- Genetics and conditions, such as diabetes and hypertension, also play a role.
Acute closed-angle (or narrow-angle) glaucoma
- Results when the angle between the iris and the cornea becomes narrowed, restricting or blocking the drainage of aqueous humor through the trabecular network and the canal of Schlemn. This causes IOP to increase suddenly.
- It may result from trauma, stress, or any process that pushes the iris forward against the inside of the cornea when there is already an anatomically shallow anterior or chamber.
- It is an acute, painful condition that can cause permanent eye damage within several hours.
Risk Factors
- Congenital
- Inherited
- Trauma
Pathophysiology
In chronic open-angle glaucoma
- Obstruction to outflow of aqueous humor through the trabecular meshwork into Schlemm’s canal leads to increased IOP. It usually is bilateral. Increased IOP eventually destroys optic nerve function causing blindness.
In acute closed-angle glaucoma
- Results in increased IOP because of obstructed outflow of aqueous humor. However, acute closed-angle glaucoma typically involves sudden, complete, unilateral closure with pupil dilation stimulated by a dark environment, emotional stress, or mydriatic drugs.
Assessment/Clinical Manifestations/Signs and Symptoms
Chronic open-angle glaucoma
- No early symptoms
- Insidious visual impairment, blurring
- Diminished accommodation
- Gradual loss of peripheral vision (tunnel vision)
- Mildly aching eyes
- Halos around lights later with elevated IOP
Acute closed-angle glaucoma
- Transitory attacks of diminished visual acuity
- Colored halos around lights
- Reddened eye with excruciating pain
- Headache
- Nausea and vomiting
Laboratory and diagnostic study findings
- Tonometry detects elevated IOP (>10 to 20 mmHg)
- Slit-lamp examination reveals abnormalities in the anterior vitreous humor.
Medical Management
- Objective of treatment is to prevent optic nerve damage by lowering the IOP to a level consistent with retaining vision. Treatment is almost always lifelong. Treatment also focuses on achieving the greatest benefit at the least risk, cost and inconvenience to the patient.
- Pharmacologic therapy is the initial and principal treatment for glaucoma. Acute angle-closure glaucoma is treated with medication (including miotics) to reduce IOP before laser or incisional iridectomy. Commonly used agents include:
- Beta-adrenergic blockers/antagonists are the most widely used hypotensive agents. They are effective in many types of glaucoma.
- Cholinergic agents (topical) are miotics (cause papillary constriction) and are used in short-term management of glaucoma with papillary block.
- Alpha-2-adrenergic agonists(topical) reduce IOP by increasing aqueous humor outflow.
- Carbonic anhydrase inhibitors (systemic) and prostaglandins lower IOP by reducing aqueous humor formation.
- Osmotic diuretics reduce IOP by increasing the osmolality of the plasma to draw water from the eye into the vascular circulation.
Surgical Management
- Ophthalmic laser surgery is indicated as the primary treatment for glaucoma or is required when medication therapy is poorly tolerated or ineffective in lowering IOP.
- Conventional surgery procedures are performed when laser techniques are unsuccessful or when patient is not a good candidate for laser surgery (eg. Patient cannot sit still or follow instructions)
- Filtering procedures: an opening or a fistula in the trabecular meshwork (trabeculectomy) is made to allow drainage implant or shunt surgery may be performed.
Nursing Diagnosis
- Anxiety related to possible vision loss
- Disturbed sensory perception related to visual impairment
- Ineffective health maintenance related to knowledge deficit
- Risk for injury related to impaired vision
- Self-care deficit related to impaired vision
Nursing Management
- Provide information regarding management of glaucoma
- Discuss preoperative and postoperative teaching for immediate surgical opening of the eye chamber.
- Prepare to administer carbonic anhydrase inhibitors IV or IM, to restrict production of aqueous humor.
- Prepare to administer osmotic agents.
- Discuss and prepare the client for surgical or laser peripheral iridectomy after the acute episode is relieved.
- Provide information about laser trabeculoplasty, if medication therapy proves ineffective.
- Teach the client about specific safety precautions.
- Instruct the client to avoid mydriatics such as atropine, which may precipitate acute glaucoma in a client with closed-angle glaucoma.
- Instruct the client to carry prescribed medications at all times.
- Instruct the client to carry a medical identification card or wear a bracelet stating his type of glaucoma and need for medication.
- Instruct the client to take extra precautions at night (e.g. use of handrails, provide extra lighting to compensate for impaired pupil dilation from miotic use).
Exam
Nursing Care Plan
Nursing Diagnosis
- Sensory Perception, disturbed: visual
May be related to
- Altered sensory reception: altered status of sense organ
Possibly evidenced by
- Progressive loss of visual field
Desired Outcomes
- Participate in therapeutic regimen.
- Maintain current visual field/acuity without further loss.
Nursing Interventions
- Determine type and degree of visual loss.
- Rationale: Affects choice of interventions and patient’s future expectations.
- Allow expression of feelings about loss and possibility of loss of vision.
- Rationale: Although early intervention can prevent blindness, patient faces the possibility or may have already experienced partial or complete loss of vision. Although vision loss cannot be restored (even with treatment), further loss can be prevented.
- Implement measures to assist patient to manage visual limitations such as reducing clutter, arranging furniture out of travel path; turning head to view subjects; correcting for dim light and problems of night vision.
- Rationale: Reduces safety hazards related to changes in visual fields or loss of vision and papillary accommodation to environmental light.
- Demonstrate administration of eye drops (counting drops, adhering to schedule, not missing doses).
- Rationale: Controls IOP, preventing further loss of vision.
- Assist with administration of medications as indicated:
- Rationale: These direct-acting topical myotic drugs cause pupillary constriction, facilitating the outflow of aqueous humor and lowering IOP. Note: Ocusert is a disc (similar to a contact) that is placed in the lower eyelid, where it can remain for up to 1 wk before being replaced.
- Stress the importance of meticulous compliance with prescribed drug therapy.
- Rationale: To prevent an increase in IOP, resulting in disk changes and loss of vision.
- Chronic, open-angle glaucoma Pilocarpine hydrochloride (Isopto Carpine, Ocusert [disc], Pilopine HS gel);
- Rationale: [Beta]-blockers decrease formation of aqueous humor without changing pupil size, vision, or accommodation. Note: These drugs may be contraindicated or require close monitoring for systemic effects in the presence of bradycardia or asthma.
- Timolol maleate (Timoptic), betaxolol (Betoptic), carteolol (Ocupress), metipranolol (OptiPranolol), levobunolol (Betagan);
- Rationale: Carbonic anhydrase inhibitors decrease the rate of production of aqueous humor. Note: Systemic adverse effects are common, including mood disturbances, GI upset, and fatigue.
- Acetazolamide (Diamox), methazolamide (Neptazane), dorzolamide (Trusopt).
- Rationale: Contracts the sphincter muscles of the iris, deepens anterior chamber, and dilates vessels of outflow tract during acute attack or before surgery.
- Narrow-angle (angle-closure) type Myotics (until pupil is constricted); Carbonic anhydrase inhibitors like acetazolamide (Diamox); dichlorphenamide (Daranide); methazolamide (Neptazane);
- Rationale:Decreases secretion of aqueous humor and lowers IOP.
- Sympathomimetids: dipivefrin (Propine), bromonidine (Alphagan), epinephrine (Epifrin), apraclonidine (Lopidine), latanoprost (Xalatan);
- Rationale: Adrenergic drops also decrease formation of aqueous humor and may be beneficial when patient is unresponsive to other medications. Although free of side effects such as miosis, blurred vision, and night blindness, they have potential for additive adverse cardiovascular effects in combination with other cardiovascular agents. Note: Light-colored eyes are more responsive to these drugs than dark-colored eyes, necessitating added considerations when determining appropriate dosage.
- Provide sedation, analgesics as necessary.
- Rationale: Acute glaucoma attack is associated with sudden pain, which can precipitate anxiety and agitation, further elevating IOP. Medical management may require 4–6 hr before IOP decreases and pain subsides.
- Prepare for surgical intervention as indicated: Laser therapy such as argon laser trabeculoplasty (ALT), trabeculectomy or trephination;
- Rationale: Filtering operations (laser surgery) are highly successful procedures for reducing IOP by creating an opening between the anterior chamber and the subjunctival spaces so that aqueous humor can bypass the trabecular mesh block. Note: Apraclonidine (Lopidine) eye drops may be used in conjunction with laser therapy to lessen or prevent postprocedure elevations of IOP.
- Iridectomy;
- Rationale: Surgical removal of a portion of the iris facilitates drainage of aqueous humor through a newly created opening in the iris connecting to normal outflow channels. Note: Bilateral iridectomy is performed because glaucoma usually develops in the other eye.
- Postoperative care after peripheral iridectomy includes cycloplegic eyedrops.
- Rationale: To relax the ciliary muscle and to decrease inflammation, thus preventing adhesions. Cycloplegics must be used only in the affected eye. the use of these drops in the normal eye may precipitate an attack of acute angle-closure glaucoma in this eye, threatening the patient’s residual vision.
- Malento valve implant;
- Rationale: Separates ciliary body from the sclera to facilitate outflow of aqueous humor.
- Cyclocryotherapy;
- Rationale: Used in intractable glaucoma.
- Diathermy or cryosurgery
- Rationale: If other treatments fail, destruction of the ciliary body reduces formation of aqueous humor
- Aqueous-venous shunt;
- Rationale: Experimental ocular implant device corrects and prevents scarring over or closure of drainage sac created by trabeculectomy.
Nursing Diagnosis
- Anxiety [specify level]
May be related to
- Physiological factors, change in health status; presence of pain; possibility/reality of loss of vision
- Unmet needs
- Negative self-talk
Possibly evidence by
- Apprehension, uncertainty
- Expressed concern regarding changes in life events
Desired Outcomes
- Appear relaxed and report anxiety is reduced to a manageable level.
- Demonstrate problem-solving skills.
- Use resources effectively.
Nursing Interventions
- Evaluate anxiety level, degree of pain experienced or suddenness of onset of symptoms, and current knowledge of condition.
- Rationale: These factors affect patient perception of threat to self, potentiate the cycle of anxiety, and may interfere with medical attempts to control IOP.
- Give accurate, honest information. Discuss probability that careful monitoring and treatment can prevent additional visual loss.
- Rationale: Lessens anxiety related to unknown or future expectations, and provides factual basis for making informed choices about treatment.
- Allow patient to acknowledge concerns and express feelings.
- Rationale: Provides opportunity for patient to deal with reality of situation, clarify misconceptions, and problem-solve concerns
- Identify helpful resources and people.
- Rationale: Provides reassurance that patient is not alone in dealing with problem.
Nursing Diagnosis
- Knowledge, deficient [Learning Need] regarding condition, prognosis, treatment, self-care, and discharge needs
May be related to
- Lack of exposure/unfamiliarity with resources
- Lack of recall, information misinterpretation
Possibly evidenced by
- Questions; statement of misconception
- Inaccurate follow-through of instruction
- Development of preventable complications
Desired Outcomes
- Verbalize understanding of condition, prognosis, and treatment.
- Identify relationship of signs/symptoms to the disease process.
- Verbalize understanding of treatment needs.
- Correctly perform necessary procedures and explain reasons for the actions.
Nursing Interventions
- Stress the importance of glaucoma screening.
- Rationale: For early detection and prevention. All people older than age 35, especially those with family histories of glaucoma, should have an annual tonometric examination.
- Review pathology and prognosis of condition and lifelong need for treatment.
- Rationale: Provides opportunity to clarify and dispel misconceptions and present condition and something that is manageable.
- Discuss necessity of wearing identification (MedicAlert bracelet).
- Rationale: Vital to provide information for caregivers in case of emergency to reduce risk of receiving contraindicated drugs (atropine).
- Demonstrate proper technique for administration of eye drops, gels, or discs. Have patient perform return demonstration.
- Rationale: Enhances effectiveness of treatment. Provides opportunity for patient to show competence and ask questions.
- Review importance of maintaining drug schedule like eye drops. Discuss medications that should be avoided such as mydriatric drops (atropine, propantheline bromide), overuse of topical steroids, and additive effects of [beta]-blocking when systemic [beta]-blocking agents are used.
- Rationale: This disease can be controlled, not cured, and maintaining a consistent medication regimen is vital to control. Some drugs cause pupil dilation, increasing IOP and potentiating additional loss of vision. Note: All [beta]-blocking glaucoma medications are contraindicated in patient with greater than first-degree heart block, cardiogenic shock, or overt heart failure.
- Identify potential side effects and adverse reactions of treatment such as decreased appetite, nausea and vomiting, diarrhea, fatigue, “drugged” feeling, decreased libido, impotence, cardiac irregularities, syncope,heart failure (HF).
- Rationale: Drug side and adverse effects range from uncomfortable to severe or health-threatening. Approximately 50% of patients develop sensitivity or allergy to parasympathomi-metics (pilocarpine) or anticholinesterase drugs. These problems require medical evaluation and possible change in therapeutic regimen.
- Encourage patient to make necessary changes in lifestyle.
- Rationale: A tranquil lifestyle decreases the emotional response to stress, preventing ocular changes that push the iris forward, which may precipitate an acute attack.
- Reinforce avoidance of activities such as heavy lifting and pushing, snow shoveling, wearing tight or constricting clothing.
- Rationale: May increase IOP, precipitating acute attack. Note: If patient is not experiencing pain, cooperation with drug regimen and acceptance of lifestyle changes are often difficult to sustain.
- Discuss dietary considerations (adequate fluid, bulk or fiber intake).
- Rationale: Measures to maintain consistency of stool to avoid constipation and straining during defecation.
- Stress importance of routine checkups.
- Rationale: Important to monitor progression and maintenance of disease to allow for early intervention and prevent further loss of vision.
- Advise patient to immediately report severe eye pain, inflammation, increased photophobia, increased lacrimation, changes in visual field, veil-like curtain, blurred vision, flashes of light and particles floating in visual field.
- Rationale: Prompt action may be necessary to prevent further vision loss and other complications (detached retina).
- Recommend family members be examined regularly for signs of glaucoma
- Rationale: Hereditary tendency to shallow anterior chambers places family members at increased risk for developing the condition. Note: African-Americans in every age category should have frequent examinations because of increased incidence and more aggressive course of glaucoma in these individuals.
- Identify strategies and resources for socialization like support groups, Visually Impaired Society, local library, and transportation services.
- Rationale: Decreased visual acuity may limit patient’s ability to drive and cause patient to withdraw from usual activities.
Other Nursing Diagnoses:
- Trauma, risk for—poor vision
- Social Interaction, impaired—limited physical mobility (poor vision), inadequate support system.
- Therapeutic Regimen: ineffective management—complexity of therapeutic regimen, economic difficulties, inadequate number and type of cues to action, perceived seriousness (of condition) or benefit (versus side effects)
