Sensory Changes of Aging module 1 Brenda K

Sensory Changes of Aging module 1 Brenda K. Keller, M. D. Geriatrics and Gerontology University of Nebraska Medical Center

PROCESS Series of 3 modules and questions on 1. Sensory Changes of Aging 2. Diseases and Disorders of the special senses 3. Treatments for vision and hearing impairment Step #1 Power point module with voice overlay Step #2 Case-based question and answer Step #3 Proceed to additional modules or take a break

Objectives Recognize physiologic changes in the sensory system. Describe the epidemiology of sensory loss. Demonstrate how to screen for sensory loss

Age Related Changes in Vision Decreased accommodation Ø hard to focus on close objects Ø Caused by gradual hardening of the lens and decreased muscular effectiveness of the ciliary body Yellow tint to vision Ø discoloration of the cornea Ø decreased sensitivity of blue-yellow receptors Reduced tolerance for glare Decreased contrast sensitivity

Contrast Sensitivity

Vision Changes with Aging Slower adaptation to low light Ø Pupil size decreases allowing less light into the eye. Decreased night vision Ø Fewer light sensing cells Ø Increased need for illumination in elderly

Normal Hearing Sound energy is transmitted through the external ear to the tympanic membrane and auditory ossicles Malleus, incus, and stapes transmit vibrations to the oval window of the cochlea Fluid waves stimulate hair cells and generate sensory potential An excitatory postsynaptic potential is generated When threshold is reached, impulses are sent via cochlear neurons to the cochlear nuclei and then to auditory pathways in the brain

Age-Related Changes That Can Interfere With Hearing External ear canal: Walls thin Cerumen: Becomes drier, more tenacious Eardrum: Thickens, appears duller Cochlea: Hair cells are lost, basilar membrane stiffens, auditory structures calcify, cochlear neurons are lost Stria vascularis: Capillaries thicken, endolymph production decreases, Na+ K+ ATPase activity decreases Brain: Atrophic changes in temporal auditory cortex

Visual Impairment Visual impairment (acuity < 20/40) Ø Prevalence increases with age Ø Affects 20% to 30% of those aged 75+ years Blindness (acuity < 20/200) Ø Prevalence: 2% of those aged 75+ years Ø 50% of blind population is aged 65 and older Most common cause of blindness in the elderly US population is ARMD; other causes are refractive error, cataract, diabetic retinopathy, glaucoma

Epidemiology of Hearing Loss % of population Prevalence increases with age 50%– 100% of nursing home residents have hearing loss Smokers have higher rates of hearing loss

The Impact of Hearing Loss The 4 th most common chronic disease among elderly persons Often considered benign, but profoundly affects quality of life May contribute to family discord, social isolation, loss of self-esteem, anger, depression Treatment can improve quality of life by facilitating interaction with family, friends, and caregivers

Screening for Vision Loss Near vision: Rosenbaum Card, 16 inches Far vision: Snellen Chart, 20 feet Fundoscopic evaluation Questionnaires

Screening for Hearing Loss Whisper test Hand held audioscope Questionnaires: HHIE Full audiometric testing- pure tone audiogram, Speech discrimination

Hearing Handicap Inventory for Elderly Identifies social and emotional impact of hearing loss. Emotional Embarrassment Frustration Handicap Family arguments Hampered social life Social Difficulty hearing • Whispers • Family conversations • Television Troubles due to hearing at: • Religious services • Restaurants

When to Refer Routine visit to Ophthalmologist q 1 -2 years, tonometry, slit lamp, full dilated exam* Refer sooner if vision worse than 20/40 * By the American Academy of Ophthalmology and USPSTF

When to Refer Otolaryngologist 1. Consult for asymmetrical hearing loss, which may indicate tumor of posterior pharynx blocking eustachian tube or auditory nerve tumor Audiologist 1. Consult to determine the presence and type of hearing loss, recommend and fit hearing aids, and provide auditory rehabilitation 2. Assessment includes evaluation of pure-tone thresholds for both air and bone conduction, speech-recognition thresholds, speech discrimination, and middle-ear function

Mild Moderately severe Severe Profound Permission to use applied for 1 -12 -07

Summary Age related changes with vision and hearing Epidemiology Screening techniques

Acknowledgments Slides adapted with permission from the American Geriatrics Society, Geriatric Review Syllabus teaching slide set. Permission granted 1 -10 -07

Post-test question one A 74 -year-old woman has difficulty seeing when she drives. Six months ago, ophthalmologic examination revealed small bilateral cataracts that did not interfere with her corrected vision, which was 20/30 in the right eye and 20/40 in the left eye. She had no signs of glaucoma or macular degeneration. Current examination confirms corrected vision of 20/30 in the right eye and 20/40 in the left eye. What is the most appropriate next step? A. Observation B. Measurement of visual acuity in ambient light C. Slitlamp examination D. Automated perimetry E. Applanation tonometry

Correct Answer: B. Measurement of visual acuity in ambient light This patient has normal visual acuity when it is measured in the office setting, but outdoor light may create a disabling glare when she is driving. Visual acuity testing in ambient sunlight will reveal the extent of this visual disability and its cause. The need for cataract surgery should be based on the extent of visual disability experienced by the patient. Cataract surgery is justified and appropriate when subjective, objective, and educational criteria are met. Used with permission from: Murphy JB, et. Al. Case Based Geriatrics Review: 500 Questions and Critiques from the Geriatric Review Syllabus. AGS 2002 New York, NY.

If the best correctable visual acuity in the affected eye is 20/50 or worse and the cataract is responsible for this impairment, then objective criteria for cataract surgery are met. However, subjective criteria are equally as important. If, as in this case, visual disability fluctuates as a result of the environment (eg, effects of glare, such as lights of oncoming cars or bright sunlight), there may be additional justification for cataract surgery. The differences between measured acuity in a darkened room (and high-contrast chart) and that with ambient light producing glare and reduction of functional acuity need to be documented. When such a verifiable reproducible loss of vision can be documented mimicking the patient's vision disturbance, the patient should be considered for cataract surgery.

In addition to the subjective and objective criteria for cataract surgery, educational criteria must also be met. The patient should be educated about the risks and benefits of cataract surgery, including treatment alternatives. The patient must determine if the expected reduction in disability outweighs the potential risk, cost, and inconvenience of surgery. As a general rule, the better the Snellen acuity, the greater the need for verification and documentation of functional disability. Additional reasons that patients may note functional disability with Snellen testing of 20/40 or better include visual disparity between the two eyes, monocular diplopia or polyopia, or the need but inability to obtain an unrestricted driving license.

A slitlamp consists of a microscope and a special light source. Slitlamp examination, also known as biomicroscopy, is indicated for any condition of the eyelids or eyeball, such as dendritic keratitis or a corneal foreign body, that can be better diagnosed and treated after evaluation using a well -illuminated and highly magnified view of the area involved. This type of examination is not appropriate for this patient. Automated perimetry is used to measure visual fields and is useful in the detection of peripheral field deficits encountered with glaucoma and for monitoring the course of glaucoma. Applanation tonometry measures the force required to flatten a small area of the central cornea in order to measure intraocular pressure. It is useful in detecting and monitoring glaucoma.

Post-test question 2 Which of the following is the most common pattern of hearing loss among older Americans? A. Symmetric high-frequency sensorineural B. Symmetric high-frequency conductive C. Asymmetric high-frequency conductive D. Symmetric low-frequency sensorineural E. Asymmetric high-frequency sensorineura

Correct Answer: A. Symmetric high-frequency sensorineural Hearing loss associated with aging affects nearly 40% of persons aged 65 and over. The prevalence is as high as 80% among nursing-home residents. Cross-sectional and longitudinal studies consistently reveal that hearing sensitivity declines with age, more prominently in high than in low frequencies. Presbycusis is the bilateral, symmetric, high-frequency sensorineural hearing loss that affects older adults. This tends to be gradual in onset and mild to moderate in severity. Risk factors include noise exposure and elevated systolic blood pressure. Overall, men have poorer hearing than women.

Presbycusis is associated with difficulty understanding speech, especially in the presence of noise. Hence, the primary complaint of older adults is that they have difficulty understanding others, especially in a noisy room or when the speaker is standing at a distance. Older adults often blame hearing loss on an accumulation of cerumen, but this usually is not responsible. Asymmetric hearing loss raises concerns about less common conditions, such as acoustic neuroma. End