This offering expires in 2 years: May 21, 2009

The goal of this CE offering is to provide information about how aging affects the eyes and how vision impairment impacts the senior patient population. After reading this article, you will be able to:

1. Discuss the impact of aging on the eyes and eyelids.

2. Discuss signs of vision impairment in the senior patient population.

3. Discuss clinical conditions related to vision impairment.

You can earn 1 contact hour of continuing education credit in three ways: 1) For im-mediate results and certificate, go to www.advanceweb.com/lpn. Grade and certificate are available immediately after taking the online test. 2) Send this answer sheet (or a photocopy) along with the $8 fee (check or credit card) to ADVANCE for LPNs, Learning Scope, 3100 Horizon Dr., King of Prussia, PA 19406. 3) Fax the answer sheet to 610-278-1426. If faxing or mailing, allow 30 days to receive certificate or notice of failure. A certificate of credit will be awarded to participants who achieve a passing grade of 70 percent or better.

Merion Publications Inc. is an approved provider of continuing nursing education by the PA State Nurses Association (No. 008-O-07), an accredited approver by the American Nurses Credentialing Center's Commission on Accreditation. Merion Publications Inc. also is approved as a provider by the California Board of Registered Nursing (No. 13230) and by the Southeastern States Board of Nursing (No. 3298).

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As far as aging is concerned, the eye is no different from other organs. Nurses must be aware of the substantive changes that occur in the eye in their assessment and care of the elderly patient.

Loss of vision may lead to profound changes for the senior patient population. Loss of the ability to drive a car due to changes in visual acuity increases isolation. Visual acuity changes may lead to lifestyle changes, such as inability to continue to work and/or enjoy leisure activities, such as reading and watching television, as well as loss of companionship. The elderly are generally at risk for depression, and visual changes may exacerbate feelings of loss of control, autonomy, independence and self-worth.

Visual acuity changes may be so subtle that they are not noted until profound, and may not be reported by the patient for fear of losing independence. These changes may put the patient at risk of falls and result in safety risks in the home. It is up to nurses to ask questions and be intimately aware of overt and covert signs of vision impairment.

Pupil Size Decrease
Functionality of the extraocular muscles changes with age. By age 70, many individuals are unable to rotate the eye upward greater than 15 degrees from the horizontal plane. The light reflex and accommodation are sluggish. There may be a defect in ocular convergence noted.

With age, the pupil size decreases, a condition referred to as miosis.¹ Because of changes in pupillary reactivity and smaller pupil size, seniors may complain of dim vision due to the limitation of light entering the smaller pupil. The pupil does not react as briskly to changes in light, and going from a darker to a brighter environment may be challenging. The decreased ability of the pupil to react to changes in light conditions leads to complaints of prolonged "blindness" when entering a dark environment. On physical exam, the pupil will not react as aggressively to direct and consensual light exposure. When doing the eye exam, consider these changes normal variants of aging.²

On physical examination, the eye of the elder may appear as sunken into the socket. While dehydration may be the rationale for this condition, loss of the orbital fat pad also brings about this change. As frailty increases and weight loss ensues, the subcutaneous fat pad further deteriorates and enhances the sunken look. Elderly individuals who are critically ill and not receiving adequate nutrition further absorb adipose tissue in the periorbital area, increasing displacement of the eye posteriorly.

Eyelid Changes
Changes in the musculature of the eyelids can lead to entropion or ectropion. Entropion is an inward turning, especially of the lower lid. When the lower lid surface is not in contact with the globe of the eye, the patient complains of excessive tearing due to inability of tears to drain properly and impact corneal intactness. Ectropion is the turning outward of the lower lid. This can lead to drying, foreign body sensation, ulceration and irritation due to inadequate hydration by lacrimal glands and normal tearing. In addition, the weakened periorbital muscles may produce incomplete lid closure during sleep, leading to foreign body sensation complaints.

The upper lid may droop (ptosis) over the eye, causing vision problems with aging. Levator muscle tone decreases and the palpebral fissure angle is decreased. This is not problematic unless the drooping lid occludes the pupil limiting vision. This can be surgically repaired.

Xanthelasma, pinguecula and pterygium also can be seen on the eye exam.

The xanthelasma is a flat or slightly raised well-defined yellowish tissue most commonly found at the nasal margin of the eyeball. It is thought to be an indicator of hyperlipidemia.

Pinguecula is a thickening of the conjunctiva. It is found at the external margin of the cornea at either the temporal or nasal aspect. It is not thought to be a significant finding.

Pterygium is thickening of the conjunctiva and connective tissue. It is triangularly shaped and located between the inner canthus and cornea. It becomes problematic if it invades the cornea and impacts vision. Surgical intervention is then required.

Blepharitis is inflammation of the hair follicles and glands along the margin of the eyelids. Signs and symptoms include redness, tenderness and sticky exudate. It may be due to bacterial invasion, allergy or environmental exposures to airborne particulate material like smoke or dust. Gently cleansing the eye to remove secretions is necessary. Depending on the etiology, antibiotic ointment may be prescribed.

Secretion Issues
As the eye ages, the lacrimal ducts may lack adequate tear secretion. This is especially problematic for postmenopausal women.² Symptoms include irritation, burning, discomfort and foreign body sensation. Data suggest a reduction in the risk of lens opacification may be a benefit of postmenopausal estrogen use. Use of estrogen is associated with decreases in nuclear and, to a lesser extent, subcapsular cataract; however, there is no association with cortical opacity. The risk of posterior subcapsular opacity increased significantly for women who experienced surgical rather than natural menopause.³

There are many over-the-counter products available to lubricate the eye and minimize the symptoms of dry eye. The nurse should know whether the patient is sensitive to preservatives in the ophthalmic solutions, which can lead to allergic reactions and exacerbate the irritation.

Lens And Refractory Changes
Glare is a common complaint of the geriatric patient. This may be nighttime or daytime glare and is secondary to changes in the crystalline lens. If visual acuity is not compromised, there is no clinical significance. During daylight hours, the use of sunglasses may help minimize the glare. Driving should not be curtailed because of glare if visual acuity is adequate.

There are a number of refractory changes due to aging. Presbyopia is the one of most common conditions in the aging eye. Its onset is during the fourth to fifth decade of life and continues to progress into the mid-sixth decade. Causation is from nuclear sclerosis of the lens and atrophy of the ciliary muscle leading to loss of accommodation.

Refractory errors may become either more hypertropic (farsighted) or more myopic (nearsighted). Older patients also may demonstrate an increase in myopia due to changes in the lens. The crystalline lens enlarges with age as old lens fibers accumulate in the lens nucleus. This accumulation makes the lens more compact and harder (nuclear sclerosis). This, in turn, increases the refractory power of the lens, which worsens the myopia.²

Arcus senilis is a common finding in the eye exam of the geriatric patient. This is a white ring noted at the margin of the limbus. It is made up of a deposit of calcium and cholesterol salts.⁴ It does not have pathologic significance. It is easier to visualize in those with a darker-colored iris.

Older men may need to have their eyebrows trimmed. As this hair continues to grow, it may cause irritation of the eye from these foreign bodies. Nurses need to coordinate trimming by barbers or may do this as an office procedure.

Flashes And Floaters
Flashing lights and floaters are common sequelae of eye changes in the elderly. The vitreous that fills the posterior eye, posterior to the lens and anterior to the retina, is a gelatinous substance. With aging, the vitreous becomes more liquid and rapid eye movement produces tension at the attachment to the retina. This tugging stimulates the peripheral retina, mechanically producing flashing lights almost always in the far temporal visual field. These flashes are called Moore's lightning streaks. If these flashing lights persist and they feel like a veil over the eye, or if there are visual field changes, they may indicate an emergent retinal detachment.⁵

In the fifth and sixth decades, but also in other age ranges, patients may see opacities appearing as lines, spots, webs and clusters of dots moving across the visual field due to vitreous detachment. The vitreous is clear; but with age, discrete opacities or structural changes may produce floaters, which may be concerning to the patient. These floaters are due to bits of vitreous that have coalesced or broken off their attachment to the retina and now are floating free in the vitreous cavity.

While annoying, floaters do not typically have any consequences. The floaters and accompanying haziness have no impact on visual acuity or ocular health. If a shower of floaters is accompanied by flashing lights, an ophthalmologist should be consulted emergently for the possibility of retinal detachment.⁵

Cataracts
Senile cataracts are due to clouding or opacification of the crystalline lens. The actual etiology of senile cataracts is not known; however, exposure to ultraviolet light is likely a contributing factor.6 Encourage patients to wear ultraviolet-protective sunglasses and hats. Other risk factors include diabetes mellitus, heredity, smoking, corticosteroid drugs, alcohol use and insufficient antioxidant vitamins.⁷

Cataracts also are a risk factor for motor vehicle collisions. Contrast sensitivity impairment increases the automobile crash risk for older drivers, whether present in one or both eyes.³

The aging lens yellows, and the discoloration filters out both short and long wavelength lights; however, the greatest change occurs in the blue and green end of the spectrum. Colors appear darker to older patients. The key to enhancing color discrimination is to maximize luminance contract. Subtle changes in color vision may indicate developing disease or adverse drug reactions, such as with digoxin. Because of this possibility, color vision should be included as part of routine exams.⁴

Related Clinical Conditions
Clinical studies provide strong correlation between visual acuity and risk of hip fracture. Binocular vision less than 20/60 is significant for increased risk of hip fracture. Other factors include no or limited depth perception (stereopsis), not wearing glasses at the time of the fall and increased time since the last eye exam. The risk of hip fracture attributed to poor visual acuity or stereopsis was 40 percent.⁶ Nursing interventions support the need for assessment of these visual parameters regardless of the clinical practice setting.

A drug history should be taken each time the elderly patient is seen. Ophthalmic solutions may be the source of adverse drug reactions for seniors, affecting multiple body systems. Some common ophthalmic solutions may include beta-blockers (timolol), adrenergics (epinephrine, phenylephrine), cholinergic/anticholinesterase (pilocarpine) or anticholinergic (atropine). Cardiac, respiratory, neurologic, gastrointestinal or other symptoms may be secondary to these solutions and should not be overlooked.

Other clinical conditions of the eye to be monitored include glaucoma, diabetic retinopathy and macular degeneration. The most common type of glaucoma is open angle. The increased intraocular pressure leads to optic nerve damage and visual field loss. Macular degeneration affects the macular area of the retina, which is the area of greatest visual acuity. Loss of vision due to macular degeneration is central loss; the individual retains peripheral vision.

Diabetic retinopathy may be present with either type 1 or type 2 diabetes mellitus. Funduscopic eye exams are necessary to assess the significance of vascular changes with diabetes. Patients should be educated on management of their blood sugar levels. Routine eye exams by an ophthalmologist should be included in the health maintenance regimen of the elderly patient.

Knowing the eye and the unique changes that occur will assist the nurse in screening and educating the senior patient. Fear of vision loss and the impact of that loss can produce anxiety, and the nurse is in a unique position to support this patient population.

References
1. Merck Research Laboratories. (1995). Merck manual of geriatrics, (2nd ed., p. 215). Rahway, NJ: Author.

2. Kane, R.L., Osulander, J.C., & Abrass, I.B. (1999). Essential of clinical geriatrics (4th ed., p. 357). New York: McGraw-Hill.

3. Worzala, K., et al. (2001). Postmenopausal estrogen use, types of menopause and lens opacity. Archives of Internal Medicine, 161(11), 1448-1454.

4. Stone, J., Wyman, J., & Salisbury, S. (1999). Clinical gerontological nursing: A guide to advanced practice (2nd ed., pp. 516-517). Philadelphia: W.B. Saunders.

5. Owsley, C., et al. (2001). Visual risk factors for crash involvement in older drivers with cataracts. Archives of Ophthalmology, 119(6), 881-887.

6. Ivers, R.Q., et al. (2000). Visual impairment and risk of hip fracture. American Journal of Epidemiology, 152(7), 633-639.

7. Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research, Cataract Management Guidelines Panel. (1993). Cataracts in adults: Management of functional impairment. (DHHS Publication No. 93-0542). Rockville, MD: Author.

Mardy Chizek is the owner and operator of Chizek Consulting Inc., a Westmont, IL-based firm specializing in healthcare risk management. <% footer %>