Caring for Clients With Sensory Disorders

UNIT 10: Caring for Clients With Sensory Disorders

Introduction to the Sensory System

  • Definitions of Key Terms:

    • Accommodation: The process by which the eye adjusts to see objects at varying distances.

    • Audiometry: The measurement of hearing acuity.

    • Caloric Stimulation Test: A test measuring the vestibular reflexes of the inner ear.

    • Central Vision: The part of vision that is focused straight ahead.

    • Conductive Hearing Loss: Hearing loss caused by problems in the outer or middle ear.

    • Conjunctivitis: Inflammation of the conjunctiva, often causing redness and swelling of the eye.

    • Decibels (dB): Unit of measurement for sound intensity.

    • Electronystagmography: A test to record involuntary eye movement to assess vestibular function.

    • Near Point: The closest point at which an object can be seen clearly.

    • Nystagmus: Involuntary eye movements, often described as oscillating.

    • Ophthalmoscopy: Examination of the interior of the eye.

    • Otoscope: An instrument used to examine the ear.

    • Proptosis: Abnormal protrusion of the eyeball.

    • Ptosis: Drooping of the upper eyelid.

    • Refraction: Bending of light rays as they pass through the eye’s lens.

    • Rinne Test: A hearing test comparing air conduction to bone conduction.

    • Romberg Test: A test for balance that assesses a person's ability to maintain equilibrium.

    • Sensorineural Hearing Loss: Hearing loss caused by issues in the inner ear or auditory nerve.

    • Tonometry: Measurement of intraocular pressure (IOP) in the eye.

    • Tuning Fork: An instrument used in hearing tests.

    • Visual Acuity: Clarity or sharpness of vision.

    • Visual Field Examination: A test to determine the range of vision.

    • Weber Test: A test used to determine the type of hearing loss.

Learning Objectives

On completion of this chapter, you will be able to:

  1. Describe the anatomy and physiology of the eyes.

  2. Discuss tests that are used for visual screening.

  3. Identify questions to ask during an eye assessment.

  4. Describe diagnostic studies for eye function.

  5. Explain the anatomy and physiology of the ears.

  6. Describe methods for assessing the ear and hearing acuity.

  7. Describe specific diagnostic tests for ear function.

Importance of Sensory Systems

  • The special senses of vision and hearing allow humans to interact with their environment and communicate.

  • Disorders in these senses can result in loss of visual acuity or hearing, affecting balance and communication.

  • Nurses play a vital role in early identification and management of eye and ear disorders, thereby reducing severity and long-term effects.

Gerontologic Considerations

  • Teaching aids with a font size of 22 or larger on an ivory background reduce glare for older adults.

  • Color perception may alter due to lens yellowing; important in medication identification.

  • Increased drier cerumen in older adults leads to a higher risk of ear impaction. Softening agents may be used, and healthcare provider referral is suggested if hearing loss persists.

  • Document findings from Rinne and Weber tests carefully for tracking hearing changes and assistive device selection (refer to Chapter 43).

Anatomy and Physiology of the Eyes

  • Eyeball Structure: The eyeball is housed in a bony orbit formed by multiple bones, including frontal, maxillary, zygomatic, sphenoid, ethmoid, lacrimal, and palatine bones.

  • Extraocular Muscles:

    • Superior/Inferior Rectus: Moves the eye up and down.

    • Medial/Lateral Rectus: Moves the eye toward/away from the nose.

    • Superior/Inferior Oblique Muscles: Rotate the eye.

    • Innervation is provided by cranial nerves:

    • Trochlear nerve (CN IV) - superior oblique.

    • Abducens nerve (CN VI) - lateral rectus.

    • Oculomotor nerve (CN III) - remaining muscles.

Extraocular Structures

  • Eyelids & Eyelashes: Protect the anterior surface of the eye; eyelids control light entry and spread tears over the cornea.

  • Conjunctiva: A transparent membrane covering the inner eyelid and eye surface, meeting the cornea at the limbus (the edge of the iris).

  • Tears: Composed of water, sodium chloride, and lysozyme, prevent drying and provide lubrication.

  • Lacrimal Apparatus: Composed of glands and ducts for tear production and drainage.

Intraocular Structures

  • Composed of three layers:

    • Sclera: The white, protective outer layer.

    • Uvea: Includes the vascular choroid and pigmented iris.

    • Retina: Contains photoreceptors (rods and cones) for converting light into nerve signals.

  • Lens: Biconvex structure that adjusts shape for focusing through a process known as accommodation.

  • Ciliary Body: Produces aqueous humor and adjusts shape of the lens for near or far vision.

Visual Function Overview

  • The eyeball converts light into nerve signals sent to the cerebral cortex.

  • Refraction: Light bending through eye structures, including cornea and lens.

  • Aging affects lens elasticity, contributing to presbyopia, and cataract formation can obstruct light passage to the macula.

Assessment of Eyes

  • The ophthalmic assessment checks external appearance, pupil responses, and eye movements.

  • Recommendations for examination frequency:

    • 20s: Complete exam once.

    • 30s: Twice.

    • 40: Baseline exam.

    • 40-60: Exam every 2 years.

    • 60+: Every 1-2 years.

Professional Roles in Eye Care

  • Ophthalmologist: M.D. or D.O. who handles medical and surgical eye treatment.

  • Oculoplastic Specialist: Ophthalmologist specializing in plastic surgery of the eye and surrounding structures.

  • Optometrist: Provides vision tests and prescribes corrective lenses.

  • Optician: Creates and fits eyeglasses or contact lenses.

  • Ophthalmic Technician: Assists in eye tests and procedures.

Nursing Assessment of Eyes

  • Key elements in assessing eye health include:

    • Patient description of vision changes and eye discomfort.

    • Use of eyewear (glasses or contacts).

    • History of eye trauma or diseases.

    • Inspection of eyes for symmetry and pupil size; response to light check.

    • Observations for significant ocular symptoms and changes in eyelid structure (ptosis vs proptosis).

  • Age-related changes: dehydration in tear production, yellowing of conjunctiva, arcus senilis, presbyopia increase, etc.

Visual Screening Tests

  • Snellen Chart: For distant vision tests.

    • 20/20 vision means normal acuity.

  • Jaeger Chart: Evaluates near vision.

  • Ishihara Plates: Used for color vision assessment.

  • Corneal Light Reflex Test: Checks the alignment of the eyes.

  • Cover-Uncover Test: Evaluates extraocular muscle function.

  • Positions Test: Assesses muscle strength.

Diagnostic Studies

  • Ophthalmoscopy: Visual examination of the retina.

  • Retinoscopy: Determines focusing power using light.

  • Tonometry: Measures intraocular pressure (norm: 12 to 22 mm Hg).

  • Visual Field Examination: Detects peripheral vision deficits.

  • Slit-Lamp Examination: Magnifies structures of the anterior eye segment.

  • Retinal Angiography: Examines blood flow in retinal vessels.

Anatomy and Physiology of the Ears

  • Structure of the Ear: Divided into three main sections: outer, middle, and inner ear.

  • Outer Ear: Includes the pinna (auricle) and external acoustic meatus, collecting sound waves.

  • Middle Ear: Contains the tympanic membrane and ossicles (malleus, incus, stapes) to amplify sound.

  • Inner Ear: Houses the cochlea (for hearing) and vestibular canals (for balance).

Assessment of Ears

  • Recommendations for hearing tests include:

    • Baseline tests in the 20s, then every decade until the 50s, and every 3 years thereafter.

  • Nursing Assessment of Ears

    • Obtaining the patient’s history regarding their hearing status and possible symptoms of hearing loss.

    • Observation of behaviors indicating hearing difficulties.

    • Performing a whisper test and inspecting the ear with an otoscope.

Tuning Fork Tests

  • Rinne and Weber Tests: Assess bone and air conduction for hearing loss.

  • Romberg Test for balance assessment, evaluating the ability to sustain equilibrium (not appropriate for all clients).

  • Audiometry: Conducted by audiologists to measure hearing.

Caloric Stimulation and Electronystagmography

  • Caloric Stimulation Test evaluates vestibular reflexes using temperature changes in the ear.

  • Electronystagmography measures eye movements in response to vestibular stimuli for balance assessment.

Key Points

  • Understanding the structure and function of the eyes and ears is critical for diagnosing sensory disorders.

  • Regular assessments and screenings help in early identification and management of sensory impairments that affect daily life activities and safety.

Clinical Judgment Exercises

  1. Explore additional data when patients report vision difficulties.

  2. Advise clients on the necessity of routine eye examinations as they age.

  3. Identify cues that indicate possible hearing impairment in older clients.

  4. Guide clients in optimal responses regarding their hearing issues and aids.

Next-Generation NCLEX-Style Review Questions

  1. Addressing age-related vision changes.

  2. Appropriate instructions for vision testing using charts.

  3. Post-cataract fluoroscopy care guidance.

  4. Best approaches for assessing a client’s hearing.

  5. Confirming normal hearing through Weber test outcomes.